57
Agostino De Marco 7 April 2014
Agostino De Marco 7 April 2014
What is JSBSim
JSBSim is a high fidelity 6 DoF flight dynamics and control software library written in the C++ programming language Simulation features bull Vehicle agnostic (completely data-driven) bull Standard or EGM96 gravitational model bull Geodetic (WGS-84) and geocentric position bull Standard or custom table-driven atmosphere bull MIL-F-8785C Turbulence model bull Mass properties update continuously bull Selectable integrators (explicit integration)
What is JSBSim
bull Flight dynamics and control SW library bull ~50000 lines of C++ code bull ~80 C++ classes bull In development since 1997 bull Data driven bull XML configuration files
httpwwwjsbsimorg
Goals of JSBSim
bull To make simulation ndash of aerospace vehicles in particular ndash more accessible
bull Ease of use and easy to learn (targeted at upper level college students)
bull Minimize input required to model a vehicle and a scenario
bull Provide for quick and easy analysis debugging
JSBSim most notable uses
bull FlightGear wwwflightgearorg bull Outerra wwwouterraorg bull BoozSimulator (Paparazzi)
wikipaparazziuavorgwikiBoozSimulator bull OpenEaagles wwwopeneaaglesorg
A team of main developers and a large base of users
JSBSim users in the world
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
What is JSBSim
JSBSim is a high fidelity 6 DoF flight dynamics and control software library written in the C++ programming language Simulation features bull Vehicle agnostic (completely data-driven) bull Standard or EGM96 gravitational model bull Geodetic (WGS-84) and geocentric position bull Standard or custom table-driven atmosphere bull MIL-F-8785C Turbulence model bull Mass properties update continuously bull Selectable integrators (explicit integration)
What is JSBSim
bull Flight dynamics and control SW library bull ~50000 lines of C++ code bull ~80 C++ classes bull In development since 1997 bull Data driven bull XML configuration files
httpwwwjsbsimorg
Goals of JSBSim
bull To make simulation ndash of aerospace vehicles in particular ndash more accessible
bull Ease of use and easy to learn (targeted at upper level college students)
bull Minimize input required to model a vehicle and a scenario
bull Provide for quick and easy analysis debugging
JSBSim most notable uses
bull FlightGear wwwflightgearorg bull Outerra wwwouterraorg bull BoozSimulator (Paparazzi)
wikipaparazziuavorgwikiBoozSimulator bull OpenEaagles wwwopeneaaglesorg
A team of main developers and a large base of users
JSBSim users in the world
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
What is JSBSim
bull Flight dynamics and control SW library bull ~50000 lines of C++ code bull ~80 C++ classes bull In development since 1997 bull Data driven bull XML configuration files
httpwwwjsbsimorg
Goals of JSBSim
bull To make simulation ndash of aerospace vehicles in particular ndash more accessible
bull Ease of use and easy to learn (targeted at upper level college students)
bull Minimize input required to model a vehicle and a scenario
bull Provide for quick and easy analysis debugging
JSBSim most notable uses
bull FlightGear wwwflightgearorg bull Outerra wwwouterraorg bull BoozSimulator (Paparazzi)
wikipaparazziuavorgwikiBoozSimulator bull OpenEaagles wwwopeneaaglesorg
A team of main developers and a large base of users
JSBSim users in the world
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Goals of JSBSim
bull To make simulation ndash of aerospace vehicles in particular ndash more accessible
bull Ease of use and easy to learn (targeted at upper level college students)
bull Minimize input required to model a vehicle and a scenario
bull Provide for quick and easy analysis debugging
JSBSim most notable uses
bull FlightGear wwwflightgearorg bull Outerra wwwouterraorg bull BoozSimulator (Paparazzi)
wikipaparazziuavorgwikiBoozSimulator bull OpenEaagles wwwopeneaaglesorg
A team of main developers and a large base of users
JSBSim users in the world
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
JSBSim most notable uses
bull FlightGear wwwflightgearorg bull Outerra wwwouterraorg bull BoozSimulator (Paparazzi)
wikipaparazziuavorgwikiBoozSimulator bull OpenEaagles wwwopeneaaglesorg
A team of main developers and a large base of users
JSBSim users in the world
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
A team of main developers and a large base of users
JSBSim users in the world
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
JSBSim users in the world
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Who is a JSBSim Developer
bull Developers ndash Add or modify C++ code ndash Integrate JSBSim into new simulation architectures ndash Compile the code ndash Interact with the code using the API ndash Use models (XML files) for testing new features
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Who is a JSBSim User
bull Users ndash Do not write C++ code ndash Do not use compilers ndash Write or use XML models ndash Interact with the simulation using properties and
XML files ndash Run the simulation to produce data ndash Analyze the data resulting from the runs ndash Unix command skills useful
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
JSBSim lsquorunning modesrsquo
bull JSBSim can be run by itself as a standalone application (batch mode) and told to connect to FlightGear via socket subsequently directing FlightGear what to display
bull The JSBSim executable for batch mode runs has a reset capability bull Reset integrator past states bull Reset flight control component past states bull Reconfigure aircraft settings in scripts bull Trim aircraft
bull Scripted runs are possible where the aircraft configuration file is loaded once but multiple runs are made such as for a set of Monte Carlo runs
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
JSBSim in batch mode
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Developer directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
User Directories
JSBSim Directory Tree (
root
)
src
aircraft
data_output
data_plot
scripts
initialization input_output math models utilities
Aero Engines Ground MassProperties Propulsion Systems
DC
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Files Needed by Users
bull Model files (vehicle engine systems aero etc)
bull Script files bull Data logging files bull Data plotting files bull Shell scripts for running monte carlo analyses
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Tools Needed
bull Bash shell (cygwin or linux) bull Gnuplot bull Prep_plot
bull Optional (pick one)
ndash Microsoft Visual C++ 20102012 Express (free devel)
ndash Notepad++ (free userdevel) ndash Matlab (non-free users post-processing)
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
User Workflow
bull Setup scenario (edit model scripts etc) ndash Run simulation ndash Auto-generate plots (eg Matlab) ndash Analyze plots ndash Modify input conditions parameters ndash Rerun
bull When ready make runs for the record bull Plot data bull Archive CSV data with input files and run
information in zip file to reduce storage reqmts bull Present results
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Analysis Computerized Model CM and Traceability
bull Must be able to recreate runs bull For any run must know
ndash Vehicle configuration ndash Dispersions ndash Environment setup ndash Other inputs and assumptions etc
bull Save all run data note executable version used and archive input data files wdata
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Key Concepts in JSBSim
bull XML bull Properties bull Functions
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
What is XML
bull eXtensible Markup Language bull A way of encoding data bull Range of tools technology and code already
available ndash Schema ndash Transforms ndash Editors ndash Parsers (JSBSim uses the eXpat library)
bull See ndash W3 Schools (httpwwww3schoolscomxml) ndash XMLorg (httpwwwxmlorg)
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
XML Elements
Format ltelementgt content ltelementgt Example ltfunctiongt ltproductgt ltcosgt 0707 ltcosgt ltvaluegt aeroqbar-area ltvaluegt ltproductgt ltfunctiongt
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
XML Attributes
Format ltelement attribute=ldquovaluerdquogt content ltelementgt
Example ltixx dispersion=ldquo700rdquo type=ldquouniformrdquo unit=ldquoSLUGFT2rdquogt 140099 ltixxgt
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Early JSBSim Data Specification ltCOEFFICIENT NAME=CLalpha TYPE=VECTORgt Lift_due_to_alpha 8 velocitiesmach-norm aeroqbar-psf | metricsSw-sqft | aeroalpha-rad 000 450 040 380 060 360 105 450 140 400 280 250 600 110 900 100 ltCOEFFICIENTgt
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Current JSBSim Data Spec ltfunction name=aeroforceCLDfgt ltdescriptiongt Delta lift due to flap deflection ltdescriptiongt ltproductgt ltpgt aerofunctionground-effect-factor-lift ltpgt ltpgt aeroqbar-area ltpgt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 025 200 030 300 035 lttableDatagt lttablegt ltproductgt ltfunctiongt
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Properties A Property is used like a Variable
bull Property names are defined in a hierarchical style ndash attitudephi-rad ndash velocitiesu-fps
bull A property can have read andor read-write access
bull There are native and created properties bull [Programmatically a property may be bound
to a program variable or a function ndash this is a concern mostly for developers]
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Aircraft FDM catalog
bull Exports a lsquocatalogrsquo of JSBSim internal properties related to the selected aircraft (Cessna 172)
bull Properties are nothing but variablevalue pairs handled during simulations
bull Each property value is lsquoexposedrsquo to the user ie can be grabbed and used for specific purposes
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
User files
Vehicle configuration file
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Vehicle configuration file
ltfdm_configgt ltfileheadergt hellip ltfileheadergt lt-- 0 or 1 instance --gt ltmetricsgt hellip ltmetricsgt lt-- 1 instance --gt ltmass_balancegt hellip ltmass_balancegt lt-- 1 instance --gt ltground_reactionsgt hellip ltground_reactionsgt lt-- 1 instance --gt ltexternal_reactionsgt hellip ltexternal_reactionsgt lt-- 0 or 1 instance --gt ltbuoyant_forcesgt hellip ltbuoyant_forcesgt lt-- 0 or 1 instance --gt ltpropulsiongt hellip ltpropulsiongt lt-- 0 or 1 instance --gt ltsystemgt hellip ltsystemgt lt-- 0 to n instances --gt ltautopilotgt hellip ltautopilotgt lt-- 0 or 1 instance --gt ltflight_controlgt hellip ltflight_controlgt lt-- 0 or 1 instance --gt ltaerodynamicsgt hellip ltaerodynamicsgt lt-- 1 instance --gt ltinputgt hellip ltinputgt lt-- 0 or 1 instance --gt ltoutputgt hellip ltoutputgt lt-- 0 to n instances --gt ltfdm_configgt
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Vehicle configuration
Geometry Masses
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Vehicle configuration Propulsion configuration files
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Vehicle configuration bull Fuel tanks bull Thrusters bull Flight Control System
(FCS)
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Vehicle configuration FCS
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Vehicle configuration
Landing gears and terrain contact
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Sim configuration
Initialization file
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Sim configuration JSBSim Script file
Example of scripted trim
(default simple algorithm)
AC model and initialization file selection
Initial final time integration interval
Event scheduling
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Functions Arbitrary functions can be defined in XML Functions are used to bull Define aerodynamics forces and moments bull Define specific control system algorithms bull Set property values in scripted events Functions support most routines available in the C language standard library (eg cos sin tan exp pow mod etc)
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Example Lift build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo AoA rate
ldquoDue tordquo pitch rate
Baseline function
ldquoDue tordquo hellip
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Example Pitching Mom build-up ldquoDue tordquo flap deflection
ldquoDue tordquo elevator deflection ldquoDue tordquo pitch rate
ldquoDue tordquo AoA rate
Baseline function
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
ltfunction name=aeromomentDfgt ltdescriptiongt Pitch moment due to flap deflection ltdescriptiongt ltproductgt ltpropertygt aeroqbar-area ltpropertygt ltpropertygt metricscbarw-ft ltpropertygt lttablegt ltindependentVargt fcsflap-pos-deg ltindependentVargt lttableDatagt 00 00 100 -00654 200 -00981 300 -01140 lttableDatagt lttablegt ltproductgt ltfunctiongt
Represents Mδf = qbar bull Sw bull cbar bull Cmδf
XML Function Example Aero
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
XML System Function Example ltfcs_function name=guidanceangle-to-roll-radldquogt ltfunctiongt ltacosgt ltsumgt ltproductgt ltpgt guidancex1a ltpgt ltpgt guidancex2a ltpgt ltproductgt ltproductgt ltpgt guidancey1a ltpgt ltpgt guidancey2a ltpgt ltproductgt ltsumgt ltacosgt ltfunctiongt ltfcs_functiongt
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
XML Script Function ltevent name=Patrick Atmosphere Temperature and Pressure continuous=tru ltdescriptiongt Implements a Patrick atmosphere by overriding temp and p ltconditiongt simulationsim-time-sec ge 00 ltconditiongt ltset name=atmosphereoverridetemperaturegt ltfunction name=atmosphereoverridetemperature-functiongt ltsumgt lttable name=atmosphereoverridetemperature-meangt ltindependentVar lookup=rowgt positionh-agl-ft ltindependentVa ltindependentVar lookup=columngt simulationmonth ltindependent lttableDatagt lt-- This data is from the Patrick AFB Range Reference At lt-- Annual January February March Apri 0 1 2 3 4 00 529128 518220 517824 522468 5277 98 528480 517788 517446 522090 5276 65620 511776 505674 504846 507528 5107 hellip hellip hellip hellip hellip hellip 2296700 394794 397080 398826 399474 392 lttableDatagt lttablegt
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Flight Control System Components in JSBSim
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
ltsensor name=fcsattitudesensorphi-radgt ltinputgt attitudephi-rad ltinputgt ltlaggt 05 ltlaggt ltnoise variation=PERCENTgt 005 ltnoisegt ltquantization name=attitudesensorquantizedphi-radgt ltbitsgt 12 ltbitsgt ltmingt -314 ltmingt lt-- -180 degrees --gt ltmaxgt 314 ltmaxgt lt-- +180 degrees --gt ltquantizationgt ltbiasgt 0001 ltbiasgt ltsensorgt
ltpid name=fcsroll-ap-error-pidgt ltinputgt fcsattitudesensorphi-rad ltinputgt ltkpgt 20 ltkpgt ltkigt 02ltkigt ltkdgt 1 ltkdgt ltpidgt
Flight Control System Components in JSBSim
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Complex Functions ltfcs_function name=ldquoguidanceheading-to-waypointrdquogt ltfunctiongt ltatan2gt lt-- atan2 (deltaY deltaX )--gt ltproductgt ltsingtltpropertygt fcsdelta-lon-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltproductgt ltcosgtltpropertygt positionlat-gc-rad ltpropertygtltcosgt ltsingtltpropertygt apwp_latitude_rad ltpropertygtltsingt ltproductgt ltproductgt ltsingtltpropertygt positionlat-gc-rad ltpropertygtltsingt ltcosgtltpropertygt apwp_latitude_rad ltpropertygtltcosgt ltcosgtltpropertygt fcsdelta-lon-rad ltpropertygtltcosgt ltproductgt ltdifferencegt ltatan2gt ltfunctiongt ltfcs_functiongt
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Output JSBSim has a versatile data logging system bullAny number of ldquooutputrdquo sections can be specified in
the configuration file but it is preferred to create individual output directive files
bull Logical data sets can be output andor individual parameters
bullOutput can be sent to one or many (in any combination)
bull Socket (local or remote) bull File bull Console
bullNormally file is sent to a CSV data file
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Output Example ltoutput name=DCcsv type=CSV rate=30gt ltmasspropsgt OFF ltmasspropsgt ltratesgt ON ltratesgt ltvelocitiesgt ON ltvelocitiesgt ltforcesgt ON ltforcesgt ltmomentsgt ON ltmomentsgt ltpositiongt ON ltpositiongt ltpropulsiongt ON ltpropulsiongt ltaerosurfacesgt OFF ltaerosurfacesgt ltaerodynamicsgt OFF ltaerodynamicsgt ltfcsgt ON ltfcsgt ltground_reactionsgt OFF ltground_reactionsgt ltatmospheregt OFF ltatmospheregt ltpropertygt velocitiesve-kts ltpropertygt ltpropertygt velocitiesmach ltpropertygt ltpropertygt flight-pathgamma-deg ltpropertygt hellip ltoutput
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Gravity Model JSBSim can use either a classical gravity model (proportional to 1r2) or the model used with the WGS-84 datum the Earth Gravitation Model of 1996 (EGM96 ndash the default) For the Dream Chaser ascent abort simulation runs we use the latter The implementation does not use the full set of 130676 coefficients but only the first coefficient which is two orders of magnitude larger than the next coefficient The gravity model is selected via the following property usually set in a script (0 = standard 1 = EGM96) simulationgravity-model [Reference Aircraft Control and Simulation Stevens and Lewis]
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Atmosphere Model The atmosphere model that is standard in JSBSim is the 1976 standard atmosphere as defined in ldquoUS Standard Atmosphere 1976 NASA TM-X-74335 We currently use the Patrick AFB Range Reference atmosphere for ascent abort runs This is satisfactory for aborts taking place entirely within a short range around the Florida launch site For more geographically expansive aborts (Charleston TAL etc) we plan to use the GRAM 2007 atmosphere model GRAM is the ldquogold standardrdquo atmosphere model and is a product of NASA Marshall Spaceflight Center
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Example Tecnam P2006T CS-23FAR-23 Certified Cockpit
Baggage compartme
nt
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Example Tecnam P2006T
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Pull manouever
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
More elaborated command hystory
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
Conclusions An easy-to-use open source software
Capability to model basic intermediate or advanced vehicles
No need to use commercial software
Interface with FlightGear
JSBSim wwwjsbsimorg
