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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/