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Avionics and Navigation
This mini-project report was submitted to the department of AeronauticalEngineering of
Kotelawala Defence University in a partial fulfillment of the requirement for the Semester-5 in
Degree of Bachelor of Science
By H.A.M. PIERIS
H.W.L. SAMARAJEEWA
P.V.S. NIRMAL
S.A. SAMARASINGHE
W.M.M.C. ABEYRATNE
Supervised by SQN LDR JI ABEYGOONEWARDENA
MR. S.L.M.D. RANGAJEEVA
Department of Aeronautical Engineering
Kotelawala Defence University
Intake 29
Group 4
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CHAPTER 1
Introduction
The design and integration of avionics systems is one of the most complicated aspects of unmanned
aircraft design. This is a problem with stringent constraints on size, weight and power consumption.
The avionics system consists of an onboard flight computer for flight data processing and a wireless
modem for live streaming of telemetry to and from the UAV to a ground station. The avionics
system in an unmanned aircraft divides in to;
Data and Communication
UAV control system and components
Ground control systems and equipment
Navigation and guidance system
1.1 Data and Communication
Data and communication system of an UAV is consisting of four main sections. They are
architecture, function, coverage and issues arising with the data communication of UAV. Due to the
architecture of UAV, whether the UAV is a military or commercial we have to give the respective
data links to connect the UAV with the ground control station. We have to give our more
consideration to the issues that are existing with the data communication such as time delay, power
and cooling systems etc.
1.2 UAV control system and components
UAV dynamic control system has categorized as auto pilot system and manual controlling system.
How we implement an autopilot system and how we manually control the UAV is mandatory in
UAV dynamics. Synchronizing these two units and necessary components will be discussed later in
our report.
1.3 Ground control systems and equipment
Groundcontrol systems is a land or sea based control center that provides the facilities for human
control of unmanned vehicles in the air or in space. A ground control system could be used to
control UAV.
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CHAPTER 2
Data and Communication
2.1 Airworthiness considerations for UAVs
Road map to Airworthiness requirements
According to the above road mapMission of the system includes
What will be the main tasks of the system?
How long does a mission take?
Where do we want to operate it?
Who is going to operate it?
No aircraft capable of being flown without a pilot over the territory of a contracting state without
special authority by that state and in accordance with the terms of such authority. Each contracting
state undertakes to insure that the flight of such aircraft without a pilot in regions open to civil
aircraft shall be so controlled as to obviate danger to civil aircraft.
Airspace will define the
Related equipment
Related procedures
Related features
In the system there should be specific needsas the UAV is an unmanned system.
A safe communication link
A flight control system
A qualified and accepted emergency plan and system
Additionally as usual in normal flight it should have the systems of
A navigation system
A detection system
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Ariel vehicle is the pre design of the aircraft.
It should have the requirements and specifications as follows.
Endurance >30 h
Altitude >45000 ft
Speed >200 kts
Payload >300 kg
Equipment >250 kg
Engine turbo prop >500 shp
Fuel >1500 kg
Span >25 m
Length >10 m
Height >4 m
Take off >1000 ft
Runaway >1500 ft
MTOW >3000 kg
2.2 Communication system
Due to the architectureof UAV it will have three categories.
Military UAV
Commercial UAV
Common UAV
•TIME DELAY
•SURVIVABILITY
•LOGISTICS
•LOCAL AREA
•LINE OF SIGHT
•OVER THE HORIZON
•UP LINK
•DOWN LINK
•MILITARY
•COMMON
•COMMERCIAL
ARCHITECTURE FUNCTION
OTHER ISSUESCOVERAGE
COMMUNICATION
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Due to the function of UAV it will have the categories of
Uplink
Downlink
Links are used to pass command and data information between the UAV and the ground
control stations.
Uplinks or command links send the command signals to UAVs from the ground stations.
True data links or down data links send data from sensors on the UAVs to their ground
stations.
Considering about the coverage
Local area
Close range operations typically use omni-directional data links
Line of sight
It is a type propagation of that can transmit and receive data only where transmit and
receive stations are in view of each other without any sort of an obstacle between them.FM
radio , microwave and satellite transmission are some examples.
Over the horizon
Communication of radio waves which are beyond the line of sight distances. This is
usually due to the scattering by the ionosphere or troposphere. It is also known as the
horizon communication.
There are someissues in UAV communication system. They are
Time delay
It is also known as the latency or lag. Each and every system has latency.
When the control latency is greater than 40ms UAV is at a high risk.(accept through an
autopilot)
Survivability
If the link has been lost there should be the survivability of the UAV. So UAVs have the
preprogrammed lost link procedures.
Power and cooling
Communication equipment (especially transmitters) requires significant power and
cooling to meet steady state and peak requirements. At low altitudes, meeting this power
and cooling requirements typically is not an issue. But in high altitudes these requirements
should be satisfied.
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Normally UAV communication system consists with Ground data terminal(GDT) and Air data
terminal (ADT).
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CHAPTER 3
Ground control Systems
3.1 Ground control data links
There are three kind of main ground control systems. We use these three system for controlling our
UAV. There are
M-GSC (main ground control station)
GDT (ground data terminal)
P-GCS (portable ground control station)
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3.2 Ground control station
A ground control station (GCS) is a land- or sea-based control enter that provides the facilities for
human control of unmanned vehicles in the air or in space. A GCS could be used to control
unmanned aerial vehicles or rockets within or above the atmosphere.
In the case of this application, the GCS is a land based control center. Video and telemetry data are
generated by the UAV’s sensors and is downloaded via the downlink to the GCS and then this
information is used in real time to guide the UAV on the operator’s desired path.
This operator’s commands, such as change in waypoint coordinate, change in direction are relayed
back to the UAV by the GCS over an uplink.
The GCS has two consoles. One for the aircraft’s main operator and one for the secondary operator.
The commands such as change in destination of the UAV can be done by just giving the longitude
and latitude coordinates of the destination. The UAV’s onboard computers will manipulate the
control surfaces in order to make the desired course change.
The information is relayed to the operators from two displays.
3.2.1 Main ground control station
M-GCS is a remote control station for UAVs that can be used for TCS (Tactical Control System). It
can transfer information to the External Control System, we can operate our UAV via satellite by
using this system but here when we give a command signal first we will have to convert it to high
voltage electrical signal and then we have to convert it to microwave signal, after that that signal
will be send to satellite and then satellite send it to our UAV. Because of this long process there is a
time delay, then we can’t do take-off and landing by using this system because of the time delay.
But after 200km we can’t use GDT system then we have to use this system. In this system two man
can control UAV because the error will be minimum.
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The M-GCS is a field-proven system that provides continuous transmission and reliable reception
of UAV data. It offers a complete C-4I solution when combined with the DSL-MK1 or MK2 Date
Link System. This rugged system is easily transportable and has minimal electrical requirements.
The M-GCS can be ready for operation within an hour of arrival at the site. User-friendly software
and setups reduce crew requirements and operator training. The M-GCS is designed around a
ruggedized military-type shelter with three operator stations, Pilot, Sensor Operator and Mission
Planner. Each station is equipped with hot-swappable PC’s for redundancy
Features
3 Dimensional Digital Map Operation
Uses skyview software
Pre-flight Path Analysis and Simulation
In-flight Real time Hazard Analysis
Autonomous flight Control command and Real time Flight Path Change
Real Time Image Processing/Display/Editing
Flight Data Analysis and Database
Mission Planning & Control
Sensors & Payload Control
Versatile the coordination system change(UTM,GP, MGRS)
Artillery Guide
Touch Monitors & Panel
IT Network Interface (Outer)
Dual System (Fault Tolerant)
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3.2.2 Portableground control station
The P-GCS can be completely free standing for ease of operational flexibility, or can be mounted in containers, trucks, SUVs and mini-vans to give easy mobility. The system can also be ship-mounted if required and integration into embedded operational systems is also possible. We can use this system for take-off and landing purposes because the time delay is very small then damages will be very rare.
Here the controller can go to the runway and then he can control the UAV by using this unit. That is the safety way to take off and landing purposes because the cross wind can effect suddenly to the UAV. The M-GSC and GDT controllers can’t feel that kind of disturbances and he is not able to see around the UAV. M-GSC operator can see only camera video feed back then it is very difficult to understand the real situation around the UAV. That’s why we use this kind of P-GCS system for landing and take-off the UAV. Here we use radio frequency for transfer data from P-GCS to UAV because of that the time delay will be very small and we use IDLS MKII data link system. The IDLS MKII is based on cutting edge technologies and combines advanced performance, modularity and light weight. Moreover, the IDLS MKII is a software defined data link which enables the system to make adaptations to customer requirements in short time with minimal effort.
Features
Can operate below 5km range. Can do safe take-off and landing within this range Battery charge up to 7 hours Use radio frequency One man can operate operate within minute from start Video feed back unit can carry anywhere and operate sun readable uses skyview software IDLS MKII data link system
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3.2.3 GDT (Ground Data Terminal)
The GDT is normally setup <100 ft. from the GCS on a hard-packed pad, preferably asphalt or
concrete. The GDT should have unobstructed line of sight to all taxiways, runways, and
approach/departure corridors. The location of the GDT also depends on and requires knowledge of
the operating area. Line of Sight (LOS) to the AV is required for operations without over the
horizon communications. The antenna shall be placed away from structures and vehicle traffic that
may result in multi-path interference. Vegetation, trees, etc., are obstructions due to high water
content.
Features
Can operate 250km range
Use radio frequency
Uses skyview software
IDLS MKII data link system
Low latency and high quality video compression
Support multi-video sensors
High bit rate transmission
Advanced & efficient modulation types. QPSK & GMSK
Color video digital compression – Industry standard MPEG, MPEG2, MPEG4, Motion JPG,
DIVX and other customized options.
Optional ECCM anti-jam capabilities
Optional COMSEC - Secure Encrypted Transmissions
Small size, lightweight and low power consumption
Automatic tracking antenna sub-system utilizing GPS and signal-strength technologies
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3.3 Skyview 10 software
The new Altitude Intercept Arc (AKA periwinkle plantain) depicts the location that the aircraft will
intercept the current altitude bug setting based on the current flight path. For example, you can set
the altitude bug at the altitude that you need to descend to to squeeze under class B airspace
Show the full name of the airport on the Nearest Airport List; Press the FILTER button to suppress
the display of airports that don't have usable runway surfaces or lengths for your aircraft.
Better IFR GPS support: Have an IFR certified GPS in your plane, but hate the small screen?
SkyView can now display the whole flight plan from an IFR GPS right on the SkyView map,
including arcs, holds, entries, and more. The text flight plan is also displayed on SkyView in the
flight planning page.
SkyView will now also follow the CDI button on your navigator, switching between VLOC and
GPS modes. If your navigator sequences automatically, SkyView will follow. No more pressing
HSI SRC on the approach as you intercept the ILS or go missed.
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Vertical Speed required to destination Info Item on map and PFD VSI displays the current VS
required to set up at a specified point at or before and above your final destination waypoint. Fly the
vertical speed number displayed to arrive perfectly at the right altitude at the right time to join the
pattern.
Features
Open source software
Can detect altitude of landmarks
Show the full name of the airport on the Nearest Airport List
Better IFR GPS support
Display the whole flight plan from an IFR GPS right on the SkyView map, including arcs,
holds and entries.
can filter the nearest list by runway type, length, and if it is a public airport
measure vertical speed
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3.4 DLS - MK II (DIGITAL Date LINK SYSTEM)
The DLS-MK2 Digital Date Link System provides the uplink and downlink communication link
between the Ground Control Station and the airborne platform. The DLS-MK2 provides a robust
link out to a range of 250KM and the digital signal enables.
Features
• Low latency and high quality video compression
• Supports multi-video sensors (optional)
• High bit rate transmission
• Advanced and efficient modulation types - QPSK and GMSK
• Color video digital compression – Industry standard MPEG, MPEG2, MPEG4,
Motion JPG, DIVX and other customized options.
• Optional ECCM anti-jam capabilities
• Optional COMSEC - Secure Encrypted Transmissions
• Small size, lightweight and low power consumption
• Extended operational range of over 140 NM / 250 Km
• Automatic tracking antenna sub-system utilizing GPS and signal-strength
technologies.
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CHAPTER 4
UAV FLIGHT CONTROL BASICS
An airplane can rotate around three axes (x y z) from the plane’s center of gravity. The position
control of UAV is usually converted to the angular control: roll (φ), pitch (θ ) and yaw (ψ ). The
axes of motion of airplanes are shown in Fig. 1.The main control surfaces or control inputs for a
fixed wing UAV may include some or all of the following:
• Ailerons: to control the roll angle.
• Elevator: to control the pitch angle (up and down).
• Throttle: to control the motor speed.
• Rudder: to control the yaw angle (left and right).
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4.1 Control Algorithm
The control algorithm consists of two layers.
1. Waypoint sequencer.
2. PID (proportional, integrative, and derivative) controller.
4.1.1 Waypoint sequencer
The action performed by the FMS (Flight Management Systems)/ RNAV (Area navigation) when
the aircraft effectively has reached the active waypoint, and then automatically switches to the next
waypoint in the programmed route.
RNAV is a method of navigation which permits the operation of an aircraft on any desired flight
path; it allows its position to be continuously determined wherever it is rather than only along tracks
between individual ground navigation aids.
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4.1.2 PID (proportional, integrative, and derivative) controller
The waypoint sequencer reads the waypoints given to the autopilot control system by the operator.
Each waypoint basically consists of 3D world coordinate which are latitude,longitude and altitude.
Based on this waypoint information and current position, attitude and ground speed, the waypoint
sequencer will output several objectives: attitude (roll, pitch and yaw/heading objective) and ground
speed objectives. These objectives will be read by PID controller as its setting point and will be
compared with actual value using PID algorithm to produce servo command value that will actuate
the airframe's surface control (aileron, elevator and rudder) and throttle.
4.1.3 The state variables of a UAV
• pn ,pe , and h : the inertial (north, east) position and the altitude or the height, e.g., latitude
longitude and height (LLH) or universal transverse Mercator (UTM) coordinates.
• vn ,ve and vd : the speeds with respect to the ground coordinate frame.
•u, v, and w : the velocities measured along body x, y, z axes.
• ax ,ay and az : the accelerations measured along body x, y, z axes.
• φ, , θ and ψ : the roll, pitch, and yaw angles.
• p, q, and r : the angular rates measured along body x, y, z axes.
• ,v α and β : the air speed, the angle of attack, and the sideslip angle.
UAV models can be used to approximate the UAV dynamics. UAVs normally have two control
modes:
remote control (RC) mode
Autopilot control mode.
Remote control mode, or radio control mode, requires human pilots to control the UAV through
radio signals, while autopilot control mode can automatically keep the airplane at the desired state.
There are also mixed control modes in some UAV applications, A semi-autonomous control mode
is provided in where the onboard autopilot controls the altitude and the human operator controls the
flight path.
4.2 Radio control
Radio controlled UAVs, which are normally controlled by an experienced
RC hobbyist through a hand-held RC transmitter with a RC receiver onboard. The signals
transmitted can be pulse position modulation (PPM) signals, or pulse code modulation (PCM)
signals. PPM also falls into the category of frequency modulation (FM). The operating frequency
for RC airplanes in United States is 72 MHz or 2.4 GHz band. The frequency is normally fixed for
RC transmitter/receiver and up to eight channels of PPM signals can be transmitted each time. After
the receiver decodes the signals from the transmitter, pulse width modulation (PWM) signals will
be generated for servo control.
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4.3 Autopilot control
An autopilot is a MEMS system used to guide the UAV without assistance from human operators,
consisting of both hardware and its supporting software. The objective of UAV autopilot systems is
to consistently guide UAVs to follow reference paths, or navigate through some waypoints. A
powerful UAV autopilot system can guide UAVs in all stages including take-off, ascent, descent,
trajectory following, and landing. Note that the autopilot is a part of the UAV flight control system
as shown in figure. The autopilot needs to communicate with ground station for control mode
switch, receive broadcast from GPS satellite for position updates and send out control inputs to the
servo motors on UAVs. A UAV autopilot system is a close-loop control system, which comprises
of two parts: the state observer and the controller. The most common state observer is the micro
inertial guidance system including gyro, acceleration, and magnetic sensors. There are also other
attitude determination devices available like Attitude Heading Reference System or vision based
ones (RGB camera). The sensor readings combined with the GPS information can be passed to a
filter to generate the estimates of the current states for later control uses.
Based on different control strategies, the UAV autopilots can be categorized to PID based
autopilots, fuzzy based autopilots, NN based autopilots and other robust autopilots. A typical off-
the-shelf UAV autopilot system comprises of the GPS receiver, the micro inertial guidance system
and the onboard processor (state estimator and flight controller) as illustrated in Fig. 3. The UAV
autopilot system has two fundamental functions: state estimation and control inputs generation
based on the reference paths and the current states.
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4.3.1 Autopilot hardware
A minimal autopilot system includes sensor packages for state determination and onboard
processors for estimation & control uses, and peripheral circuits for servo & modem
communications. Due to the physical limitations of small UAVs, the autopilot hardware needs to be
of small sizes, light weights and low power consumptions. The accurate flight control of UAVs
demands a precise observation of the UAV attitude in the air. Moreover, the sensor packages should
also guarantee a good performance, especially in a mobile and temperature-varying environment.
4.3.1.1 MEMS System
Micro-Electro-Mechanical Systems, or MEMS, is a technology that in its most general form can be
defined as miniaturized mechanical and electro-mechanical elements (i.e., devices and structures)
that are made using the techniques of microfabrication.
4.3.1.2 MEMS inertial sensors
Inertial sensors are used to measure the 3-D position and attitude information in the inertial frame.
The current MEMS technology makes it possible to use tiny and light sensors on UAVs. Available
MEMS inertial sensors include:
(1) GPS receiver: to measure the absolute positions
( pn ,pe , h) and ground velocities (vn , ve , vd )
(2) Rate or gyro: to measure the angular rates (p, q, r ).
(3) Acceleration: to measure the accelerations (ax, ay, az).
(4) Magnetic: to measure the magnetic field, which could be used for the heading correction (ψ ).
(5) Pressure: to measure the air speed (the relative pressure) and the altitude (h).
(6) Ultrasonic sensor or SONAR: to measure the relative height above the ground.
(7) Infrared sensor: to measure the attitude angles (φ,θ ).
(8) RGB camera or other image sensors
4.3.2 Sensor selection
Based on the Control Algorithm Development step, there several measurements needed by the PID
control scenarios .These measurements are position measurements and attitude measurements. For
acquiring position measurements, a GPS receiver issued. The uBlox TIM-LA is chosen because it's
relatively low cost and can provide 4 position information (speed, latitude, longitude, altitude and
heading) every second (4Hz). For measuring roll and pitch angle, the best solution would be using
Attitude and Heading Reference System (AHRS). AHRS consists of inertial sensors (gyroscope and
accelerometer) and magnetic field sensor (magnetometer).Strap down inertial navigation
mechanization and proprietary fusion algorithm is usually used in combining the sensor readings to
produce reliable attitude information.
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4.3.2.1 GPS Module U Blox TIM- LA
u-blox is an international company headquartered in Switzerland, with sales organizations in the
Americas, Europe and Asia. Founded in 1997, u-blox develops leading positioning products based
on the Global Position-ing System (GPS) for the automotive and mobile communications markets.
TIM-LA is a cost-optimized module equipped with a low noise amplifier and suitable for passive
antennas. It is powered by the 16- channel and shows superior performance in any static and
dynamic environment, particularly in the most challenging metropolitan areas.
In addition, TIM-LA provides high sensitivity (-150 dBm) without compromising navigation
accuracy, advanced WAAS / EGNOS support, excellent acquisition performance with 34 s cold
start time, and highly effective multi-path suppression. The low power consumption (150 mW and
under), the power-saving mode and the built-in low noise amplifier make the TIM-LA especially
attractive for battery-operated devices with stringent space and power requirements.
4.3.2.2Attitude Heading Reference System
Attitude Heading and Reference Systems better known as AHRS is a 3-axis Inertial Measurement
Unit (IMU) combined with a 3-axis magnetic sensor, and an onboard processor that creates a virtual
3-axis sensor capable of measuring heading (yaw), pitch, and roll angles of an object moving in 3D
space.
AHRS sensors were originally designed to replace the large traditional mechanical gyroscopic
aircraft flight instruments and provide better reliability and accuracy. Typically an AHRS will
consists of either a fiber optic (FOG) or MEMS 3-axis angular rate gyro triad, a 3-axis MEMS
accelerometer, and a 3-axis magnetic sensor known as a magnetometer. A onboard Kalman filter is
used to compute the orientation solution using these various measurements. Some AHRS sensors
will also use GPS to help the gyro drift and provide a more accurate estimate of the inertial
acceleration vector.
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Parts that make up an AHRS
An AHRS starts with a calibrated Inertial Measurement Unit. In some cases this is provided as a
single drop in part, in other cases it is constructed using separate single-axis accelerometers and
gyroscopes. A magnetometer is added to the sensor package to measure the magnetic field vector. A
32-bit processor or DSP is added to provide a platform to run a Kalman filter attitude estimation
algorithm. VectorNav specializes in high performance inertial measurement units, orientation sensors and
inertial navigation systems using the latest miniature solid-state Micro-Electro-Mechanical Systems
(MEMS) inertial sensor technology.
The VN-200 Rugged (capable of withstanding rough handling) is a miniature high-performance
GPS-Aided Inertial Navigation System combining the MEMS inertial sensors and high-sensitivity
GPS receiver, and advanced Kalman filtering algorithms to provide optimal estimates of position,
velocity, and orientation for industrial applications with a lightweight, robust aluminium enclosure.
Utilizing the latest advancements in MEMS technology, the VN-200 incorporates a wide
assortment of inertial sensors including a 3-axis accelerometer, 3-axis gyroscope, 3-axis
magnetometer, and a barometric pressure sensor. The VN-200 has been carefully designed to
provide the highest performance achievable, by eliminating common error sources such as
sensitivity to supply voltage variations and temperature dependent hysteresis. To provide the
highest level of accuracy, each VN-200 is individually tested and characterized over the full
operating temperature range to determine the bias, sensitivity and cross-axis alignment for each
individual sensor. Calibration coefficients are stored on the sensor and are fully temperature
compensated in real-time onboard to ensure high accuracy measurements over the full operating
temperature range.
The VN-200 is the smallest, lightest, and lowest power GPS/INS available on the market. The
sensor package and all electronics are housed in a rugged aluminum enclosure. Precision
alignment holes are provided to ensure accurate installation.
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Advantages in using VN-200 Rugged GPS-Aided Inertial Navigation
System
In GPS/INS for Unmanned Aerial Vehicles
The VN-200 provides exceptional performance for control of unmanned
aerial platforms. With an update rate of 200 Hz, high bandwidth, low-
latency position and attitude measurements can be directly connected
to the necessary control loops. The VN-200 calibration procedures ensure a high accuracy pitch
and roll solution relative to the horizon while the on-board barometric pressure sensors provide
autonomous aircraft with greater ability to precisely hold altitude.
High Sensitivity GPS Receiver
The VN-200 incorporates an onboard high sensitivity 50-channel u-blox GPS module. A
MCX connector is provided for connection to an external active antenna.
Receiver Type: 50-channel u-blox GPS L1 C/A
Update Rate: 5 Hz
Sensitivity: -159 dBm Tracking
Cold Start: 27s
(VN-200S)
Is calibrated for bias, scale factor, misalignment errors and gyro g-sensitivity at 25° C
(VN-200T)
Is over the entire operating range of the sensor (-40° C to +85° C).
Only a single 3.2 - 5.5V power supply is required.
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4.3.2.3 0.74M Ku-Band Rx/Tx Antenna (Series 1742)
We use antennas in uav to transmit and receive the signals with ground control unit. In this type we
can fulfill both the requirements.
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4.3.2.4 Heating system
At high altitudes the temperature is very low. So in order to avoid uav electrical systems being
damaged at high altitudes, we use a heating system.
Cox & company 2950 Series Temperature Control Systems — Power levels from 250
to 1,000 watts.
4.3.2.5 Pan-Tilt Unit-D300 E Series
The PTU-D300 E Series is a precision pan-tilt designed for extreme performance on demanding
applications. It provides high-speed, accurate positioning of camera, laser, antenna, or other
payloads up to 70 lbs. or more. It features a integrated Ethernet, programmable ranges of motion,
and enhanced motion control. The PTU-D300 E Series includes a fully integrated controller with
single weatherized connection for outdoor fixed and mobile applications.
Payloads to 70 lbs
Integrated slip-ring for 360-continuous pan rotation
Small form-factor
Under 29 lbs.
Tilt position resolution down to 0.00625°
Pan/tilt speeds up to 100° / Sec.
Wide range DC voltage input
Integrated Ethernet
Programmable ranges of motion
High resolution digital encoders
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Uses of this are:-
Comparison of the attitude of the airplane with the main gyro system.
Can mount a camera to avoid obstacles in the line of motion of the airplane.
That camera can be rotated any direction by this system, So we can use this for surveillance
purposes also.
4.3.2.6 Lumenera’s Lg11059 Camera
The Lg11059 is an 11 megapixel camera that provides 5 fps at full 4008 x 2672 resolution. This
industrial-grade camera with a 35 mm high resolution CCD sensor and a fully integrated Canon EF
lens controller makes it an ideal solution for demanding environments such as UAVs. Additionally,
a fully global electronic shutter takes a snapshot at a precise moment where all rows are captured at
the same time and light intensity, resulting in high-speed images with zero blur. The Lg11059
camera utilizes its high quality CCD sensor to its maximum by providing either vivid color or very
sensitive visible light and near IR monochromatic images.
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Full streaming of uncompressed video along with still image captures are easily controlled through
our standard API interface or through the GigE Vision interface. Region of interest and binning
modes allow the camera to run at faster frame rates (14 fps at 640 x 480 resolution) while providing
only the needed image data.
Image capture synchronization is achieved using either a hardware or software trigger, and is
complemented by 32 MB of on board memory for frame buffering to ensure image delivery. The
robust and compact design of the Lg11059, measuring 76.2 x 76.2 x 82.6 mm, makes it ideal for
installation into compact systems where space is at a premium. The fully locking Gigabit Ethernet
cabling, power connector and digital I/O interface ensure a simple plug-and-play installation,
minimizing camera clutter with only one standard cable. Simplified I/O cabling is provided through
a locking Hirose connector supporting 4 output and 3 input ports that can be automatically or
manually controlled through software. The use of locking connector ensures reliable operation even
under high vibration environment. The camera is void of fans or cooling holes further increasing
reliability.
SDK Application
The Lumenera Camera SDK provides a full suite of features and functions that allow you to
maximize the performance of your camera within your application. The SDK is compatible with all
USB and GigE based cameras. Microsoft DirectX/DirectShow, Windows API and .NET API
interfaces are provided allowing you the choice of application development environments from
C/C++ to VB.NET or C#.NET. Full inline IntelliSense autocompletion and documentation is
provided with the .NET API interface and is accompanied by a full API manual describing all the
camera functions and properties.
Highlights
• Lumenera’s Lg11059 offers is an 11 megapixel camera that provides 5 fps at full 4008 x 2672
resolution
• Provides either vivid color or very sensitive visible light and near IR monochromatic images
• Full streaming of uncompressed video along with still image captures are easily controlled
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4.3.2.7 Honeywell DC001NDR4 Silicon Pressure Sensor
Here we use pressure sensor to detect speed of the uav. It measures the actual velocity.
.
4.3.3 Autopilot software
All the inertial measurements from sensors will be sent to the onboard processor for further filter
and
Control processing. Autopilot could subscribe services from the available sensors based on different
control objectives.
4.3.3.1 State observation
The autopilot processor needs to collect all the sensor readings in real time. Then all these state
observations are passed on for further processing.
4.3.3.2 Autopilot control objectives
Most UAVs can be treated as mobile platforms for all kinds of sensors. The basic UAV waypoints
tracking task could be decomposed into several subtasks including:
(1) Pitch attitude hold.
(2) Altitude hold.
(3) Speed hold.
(4) Automatic take-off and landing.
(5) Roll-Angle hold.
(6) Turn coordination.
(7) Heading hold.
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4.3.3.3 State estimation
To achieve the above control objectives, different system states are needed with relatively high
frequency
However, sensors like GPS can only provide a noisy measurement in 4Hz. Kalman filter can be
used here to make an optimal estimation (H2) of the current states including the UAV location,
velocity and acceleration. The users need to define a noise estimation matrix, which represents how
far the estimate can be trusted from the true states. Kalman filtering needs lots of matrix
manipulations, which adds more computational burden to the onboard processor. Therefore, it is
necessary to simplify the existing Kalman filtering techniques based on different applications.
Besides, several other issues like gyro drifting and high frequency sensor noise also need to be
canceled out through filtering techniques.
4.3.3.4 Controller design for autopilots
Most current commercial and research autopilots focus on GPS based waypoints navigation. The
path-following control of the UAV can be separated to different layers:
(1) Inner loop on roll and pitch for attitude.
(2) Outer loop on heading and altitude for trajectory or waypoints tracking.
(3) Waypoint navigation.
There are two basic controllers for the UAV flight control: altitude controller, velocity and heading
controller. Altitude controller is to drive the UAV to fly at a desired altitude including the landing
and take-off stages. The heading and velocity controller is to guide the UAV to fly through the
desired waypoints. To achieve the above control requirements, different control strategies can be
used including PID, Most commercial autopilots use PID controllers. Given the reference waypoint
coordinates and the current UAV state estimates, the controller parameters of different layers can be
tuned off-line first and re-tuned during the flight. Most commercial autopilots use traditional PID
controllers because they are easy to be implemented on the small UAV platforms. But the PID
controllers have limitations in optimality and robustness. Besides, it is also difficult to tune the
parameters under some circumstances.
Sets of PID (proportional, integrative, and derivative)
4.4 Synchronization between autopilot software and microprocessors. (Final Analysis)
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Auto pilot system consist two microprocessors . One is for program the flight path using way point
navigation. And other one to identify the measurements from the sensors
Ex- gyro, accelerometer, GPS
These two micro processers are synchronized using PID. Sensor detected measurements (actual
flight path) and programmed flight path is compared using PDI algorithm to produce servo
command value that will actuate the airframe surface control and also current position, (pitch, roll,
yaw), acceleration, air speed, magnetic field altitude and camera view.
Ground control can identify the barriers in the flight path and control the UAV manually using
remote controller.
Conclusion
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Here in this our mini project finally we were able to complete the areas which are included in the
UAV Avionics system.
We first considered about the Airworthiness regulations pertaining to UAV because these
considerations are much important when constructing the avionic system as well as the whole UAV.
We have to give our consideration into four main categories to pertain the airworthiness
requirements for our desired UAV.
We have introduced an auto pilot unit to fly the UAV in the optimum flight path. It will help in the
self-control of the UAV. The programmed flight path is programmed and included in the autopilot
system to navigate the UAV.
When identification the UAV position we have found the required instruments to fulfill the
necessary requirements. The indications of GPS, Rate gyro, accelerometer, magnetometer, pitot-
static tube, are sensed by the respective sensors and giving the required measurements to the ground
control station.
According to the airworthiness requirements also, there should be a system to control the UAV in
case of an emergency like loss of controlling data link. These can be due to cases like fire, failure of
a system, barriers, hacking. So we have introduced a mechanical control system to control via
ground control station in case of an emergency.
We have also given our concern to the methods of generating feedback for ground control station.
We have implemented our Avionics system to generate the error messages in the ground control
station if the given conditions are not met. These errors will be transmitted to ground control via the
microwave link.
Finally we have designed our avionics system of the UAV as we have discussed in the report with
having the contribution with the other teams also.
References
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1. ohn M. Seddon, Simon Newman. Basic Helicopter Aerodynamics p216, John Wiley and
Sons, 2011. Accessed: 25 February 2012. ISBN 1-119-99410-1. Quote: The rotor is best served by
rotating at a constant rotor speed
2. http://www.groundcontrol.com/Satellite_Dish_Equipment.htm
3. Unmanned Air-system (www.rohaUAV.com) .pdf
4. Amie Stepanovich. "Unmanned Aerial Vehicles and Drones". Electronic Privacy
Information Center. Retrieved 2012-06-19.
5. http://www.unmannedsystemstechnology.com/company/sri-international-sarnoff/