+ All Categories
Transcript
Page 1: Outline - ntrs.nasa.gov
Page 2: Outline - ntrs.nasa.gov

Outline

♦ As Background:

• Project Orion Mission

• iGNC role in Orion Program

♦ Design and Development Plans:

• External Interfaces

• Functional Architecture

• GN&C Software Overview

• Development and Validation Process

• Key Challenges

Orion Integrated GN&C / K. Chevray Page 2

Page 3: Outline - ntrs.nasa.gov

Injection Burn REO D

LaunchOn AbortCLV (contingency) Precision landing in

US coastal waters

Deorbit Burn

JettisonSM

Precision landing inUS coastal waters

JettisonSM

Injection Burn

LaunchOnCLV

Abort(contingency)

Project Orion Mission At-A-Glance

ISS Design Reference MissionAltair/Crew onSurface Trans-Earth

Injection BurnsUncrewed

Ref: Orion GN&C Subsystem Design ReviewFebruary 2009

Lunar Design Reference MissionOrion Integrated GN&C / K. Chevray Page 3

Page 4: Outline - ntrs.nasa.gov

Integrated GN&C(iGNC)Role within Oriong

♦ Orion GN&C team operates under Multiple Organizational Designand Engineering (MODE) team agreement between NASA and primecontractor, Lockheed-Martin (LM)

n MODE team arrangement allows NASA engineers to collaborate with theprime contractor during design process

• Allows to leverage off of NASA’s experience with manned systems

• Allows greater insight into prime contractor’s design

• Each MODE team within the GN&C Subsystem Products Team (GNC SPT) isco-led by a NASA lead and a LM lead

♦ As a NASA side lead, I have responsibilities on both sidesn As a System Manager, monitor design activities and evaluate the design

• 30 System Managers and 80 Subsystem Managers

n The roles are expected to diverge after CDR, as LM personnel concentrateson test and verification while NASA personnel will focus on assessment of LMdata for vehicle acceptance

Orion Integrated GN&C / K. Chevray Page 4

Page 5: Outline - ntrs.nasa.gov

iGNC Role within Orion (cont’d)

♦ iGNC is a MODE team that is responsible at the subsystem level for:• Systems Engineering

• Inter-MODE team integration and external interfaces

• Requirements

• Flight software architecture including Phases, Segments, and Modes

• Fault Detection, Isolation, and Recovery (FDIR)

• Test and Verification

• Simulation development

♦ In addition, iGNC personnel participates in the following activitieswith other organizations

• Constellation (level II) requirements coordination through Flight PerformanceSystem Integration Group (FPSIG) – CARD and IRD requirements

• Coordination with the International Space Station (ISS) for Rendezvous,Proximity Operations, and Docking (RPOD) related topics – Orion/ISS IRDrequirements, docking conditions

Orion Integrated GN&C / K. Chevray Page 5

Page 6: Outline - ntrs.nasa.gov

MODE Team Responsibilities

♦ Integrated GN&C (iGNC):n Requirements, verification, sim development, and technical integration

♦ Ascent Abort (AAMT):n Handles GN&C for all ascent aborts including LAS and SM aborts

♦ Orbit (OMT):n Handles navigation filter design and GN&C for on-orbit, transit, and RPOD

♦ Entry (EMT):n Handles entry GN&C including CM burns, guided entry, and roll under mains

♦ Operability and Piloting (OPMT):n Handles manual control, flight displays, and ops interfaces across mission

♦ Contingency Return (CRMT):n Handles GN&C for BEC/MRC vehicle capabilities

♦ Navigation Systems (NavSys):n Nav hardware design and system integration across all mission phases

Orion Integrated GN&C / K. Chevray Page 6

Page 7: Outline - ntrs.nasa.gov

Aerosciences Thermal• aero database • trajectories

Models &Sims Loads & Dynamics• models from Osiris • dynamic environment

database • trajectories

Propulsion (PROP)• thruster specifications• thruster commanding• thruster configuration

Guidance,Navigation &

Control(GNC)

EnvironmentalControl and LifeSupport (ECLS)• active thermal

control of VPU & IMU• venting constraints

Crew Health andHabitation

Accommodation(CHHA)

• VNS & DockingCamera stowage

External Interfaces

Avionics (AV)• transfer commands and data to / from

sensors & effectors• data for crew displays & other constellation

elements• health / status, FDIR & test report data

• abort & contingency data• phase, segment, activity & mode data

• crew and ground commands• range, range rate & bearing

• command latency & resolution• memory and processing resources

Landing andRecovery Systems

(LRS)• trigger conditions

notification• vehicle control fordescent and landing

Electrical Power(EPS)• power

Thermal Protection Mechanisms (MECH) Structures (STR)Wiring (WIRE) System (TPS) • docking mechanism • sensor mounting• power & signal • thermal protection for constraints • windows for optical

distribution Star Tracker sensors

Org Org Org Provides Org ProvidesDriving Interface SEIT (Subsystem to Subsystem) Other Organizations Provides Receives & Receives & Receives

Ref: Orion GN&C Subsystem Design ReviewOrion Integrated GN&C / K. Chevray Page 7 February 2009

Page 8: Outline - ntrs.nasa.gov

Ref: Orion GN&C Subsystem Design ReviewOrion Integrated GN&C / K. Chevray Page 8 February 2009

606E GN&C Subsystem Boundary DiagramY rY ramg

Backup Flight System

GN&C Software

Page 9: Outline - ntrs.nasa.gov

r---------------------------1 Guidance/Targeting

------

i i

-------------------------- -------^

Guid Health Ascnt EntryFTaMgmt TargGuid TargGuid Guid

CSCI = Computer SW Configuration ItemCSC = Computer SW ComponentCSU = Computer SW Unit

"Domains”/CSCs(CSU detail not shown here)

Ownership

Ascent Abort MODE Team

Orbit MODE Team

Entry MODE Team

Navigation Systems

Propulsion

Orion GN&C FSW Overviewz ^

Flight Computer/VMC

FCM (SCP)

DCM (SCP)

CCM

VMC = Vehicle Mgmt ComputerFCM = Flight Control ModuleDCM = Display Control ModuleCCM = Communications Control ModuleSCP = Self Checking Pair (of processors)

"CSCIs“(1 SRS per CSCI)

Rate Grou ps, Hz (ms)40 (25 ms) - High20 (50 ms) - Med-High10 (100 ms) - Med5 (200 ms) - Med-Low1 (1000 ms) - Low

Note:D&C HW/SW reuse requires data ratesin multiples of 20Hz (50 ms).

input output

GNCP Partitions

Navigationr--------------------------- ------

GNC Cmd Interface

---------------------------- -----^

Control/Propulsion-------------------

Cntrl Health LAS- CM- SM-i Mgmt Cntrl Cntrl Cntrl

Mass PropSys EngineProp Cntrl Cntrl

----------------------------------i

CSC CSC iCSU CSU

CSU CSU ii

Nav Health Abs Rel EphemMgmt Nav Nav Proc

Time/Space(notional)

ARINC 653 Partitions

SKP IOP ANAV GNCP IOP CDH CMT ADL TM

Multiple rate groups can reside within the partition. Ref: Orion GN&C FSW OverviewOrion Integrated GN&C / K. Chevray

Page 9

W. Tamblyn

Page 10: Outline - ntrs.nasa.gov

!!: Development processment and validationz ^ p p

♦ GN&C MODE teams responsible for the development of GN&Calgorithms

n Guidance, navigation, control, executive, FDIR, parameters for display

♦ Algorithms documented in modeled based design tool(Matlab/Simulink)

n FSW provides the executive architecture• Architecture developed by GN&C FSW architecture working group, co-led by GN&C

and FSW

n GNC provides the detailed algorithms within the architecture (CSCI’s)

n Simulation capability to close the loop directly with the FSW algorithms duringthe development phase

♦ Auto-coded version of the Matlab/Simulink becomes the flightsoftware at the CSCI level

♦ Flight software then will get tested and verified via various testfacilities

Orion Integrated GN&C / K. Chevray Page 10

Page 11: Outline - ntrs.nasa.gov

Key Challenges

♦ Communication• With the size of Orion Project and the GN&C team, maintaining an open

communication channels is difficult• Need to find the right balance of enough participation to make correct decisions vs.

too many people attending too many meetings to get the “real” work done♦ Horizontal vs. vertical integration

• GN&C team is organized by flight phase, which allows for easier integration insidea given phase. iGNC is responsible for horizontal integration across various flightphases, which requires matrixed support from flight phase teams.

♦ Requirements management• Flow down from Level II (Constellation Program) and Level III (Orion Project)

through Crew Module and Service Module Specifications to GN&C Specifications• Performance allocations at the vehicle level• GN&C subsystem spec vs. flight software requirements• How many requirements is too many?

♦ Test and verification• Development vs. formal verification testing• Testing at subsystem vs. system level• Time required to complete the verification in test facilities

Orion Integrated GN&C / K. Chevray Page 11


Top Related