UAVS Project - (BEng Aerospace Dissertation)

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UAVS Project - (BEng Aerospace Dissertation)
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Bhat, U. 2009. UAV Project 2009, BEng Aerospace Technology Dissertation. Faculty of Engineering and Computing, Coventry University.

Unmanned Arial Vehicles have seen an unprecedented growth in recent years in both military as well as civilian application domain. This has increased the interest and research in unmanned technology at academic level. Coventry University as also invested in technology related to development of UAVs like an autopilot and flight simulators. This report details the work done on implementation of an autopilot system on UAV and simulation of the aircraft.

NOTE: I am putting this online just to give the undergraduate students an example of a final year dissertation. Please do not copy as it will be considered plagiarism by your university.

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C O V E N T R Y

U N I V E R S I T Y









Faculty of Engineering and Computing

Department of Aerospace Engineering

BEng Aerospace Technology



388SYS Individual Project





UAVS Project 2009



Author: UBAIER AHMAD BHAT

Supervisor: DR. S M HARGRAVE



Submitted in partial fulfilment of the requirements for the Degree of Bachelor of

Aerospace Technology





2008 - 2009

“I have not failed. I've just found ten

thousand ways that won't work.”



--Thomas Alva Edison

DECLARATION





The work described in this report is the result of my own investigations. All sections

of the text and results that have been obtained from other work are fully referenced.

The dissertation and the original work related to it have not been submitted to any

institute for an academic award. I understand that cheating and plagiarism constitute

a breach of University Regulations and will be dealt with accordingly.









Signed: Date:









i

ABSTRACT

Bhat, U. 2009. UAV Project 2009, BEng Aerospace Technology

Dissertation. Faculty of Engineering and Computing, Coventry

University.



Unmanned Arial Vehicles have seen an unprecedented growth in recent years

in both military as well as civilian application domain. This has increased the

interest and research in unmanned technology at academic level. Coventry

University as also invested in technology related to development of UAVs like

an autopilot and flight simulators. This report details the work done on

implementation of an autopilot system on UAV and simulation of the aircraft.



The approach used for this project was to get familiar with the autopilot

system (Micropilot MP2028g) and install it onto an aircraft. The project also

involved an attempt to simulate and analyse of the pitch dynamics of the

aircraft model acquired.



The autopilot was implemented on a test aircraft and was tested on ground

but a flight test did not take place. Different packages for simulations and

problems related to them were also investigated.









Keywords: unmanned aerial vehicle, UAV, autopilots, flight simulation,

modelling.









ii

CONTENTS



Declaration i

Abstract ii

Table of Contents iii

Acknowledgements and Dedication v



1. INTRODUCTION 1



1.1 Aims and Objectives of the Project 1

1.2 Outline of the Report 1

1.3 Modifications to project aim. 2



2. LITERATURE REVIEW 3



2.1 Unmanned Arial Vehicles 3

2.1.1 Introduction 3

2.1.2 Types of UAVs 3

2.1.3 Components of a UAV System 5

2.1.4 Applications 6



2.2 Stability and Automation of UAVs 8



2.3 Dynamics of Flight 10

2.3.1 Introduction 10

2.3.2 Six Degrees of Freedom (6DOF) 10

2.3.3 Pitch dynamics and Longitudinal stability 10



2.4 Modelling and Simulations 12

2.4.1 Introduction 12

2.4.2 Modelling and Simulation Techniques 12

2.4.3 Applications 12

2.4.4 Problems 13



2.5 System Identification 14





3. UAV PLATFORM 15



3.1 INTRODUCTION 15

3.2 TEST PLANE 15

3.3 2009 UAV PLATFORM 18



4. THE AUTOPILOT 20



4.1 Introduction 20

4.2 Components 20

4.3 Installation 22



iii

4.4 Working and Configuration 23

4.5 Problems 23







5. FLIGHT SIMULATOR 25



5.1 Introduction 25

5.2 Merlin Flight Simulator 25

5.3 Flight Simulation Modals 28

5.4 Flight Tests 28



6. System Identification using AeroSim 33



7. Conclusion 39



8. Further Work and Recommendations 40



9. References 41



10. Bibliography 42



11. Appendixes



A Initial Documentation and Interim Report I



B Test Results IX









iv

ACKNOWLEDGEMENTS AND DEDICATIONS



I would like to thank Dr. Stephen Hargrave for supervising the project and helping

me throughout the course. I would also like to thank Mr. Basini, Mr. Fisher, Dr.

Lambert and Mr. Thorley for their help for the project and the course.



I would also like to thank fellow students Mohammad Bahrami, Arnaud Dupin,

Thomas Gobeaut, Douglas Mackenzie and Kelvin Nelson.



I would like to thank Allah for giving be strength and patience throughout the project

and the course. I would also like to thank my family for their financial and emotional

support.



I would also like to dedicate this project to those innocent children who have been

killed in UAV strikes worldwide and pray that the unmanned technology is not used

for any inhumane activities.









v

CHAPTER 1: INTRODUCTION





CHAPTER 1: INTRODUCTION

1.1 Aims and Objectives of the Report



The report presents the details of the work done on implementation of MicroPilot

MP2028g autopilot on the UAV platforms developed in the university. The report also

presents the results of research into the modelling and simulation of the UAV. The

main objectives set for the project were as follows:



1. Familiarisation and implementation of the MicroPilot 2028

2. Familiarisation with Merlin Flight Simulator and modelling and simulation of

the UAV.

3. System identification and generation of linearised model of the pitch dynamics

of the aircraft.



1.2 Outline of the Report



Chapter 2: Literature Review:

This chapter background information about UAVs and their applications, Automation

of aircrafts, modelling and simulation of systems.



Chapter 3: UAV platform

This chapter gives details about the UAV platforms used for the project.



Chapter 4: Autopilot

In this chapter details about the MicroPilot MP2028g along with some information

related to installations and setup.



Chapter 5: Flight Simulation

This chapter contains detailed information about Merlin Flight simulators and gives

some details modelling and simulation of the aircraft.



Chapter 6: System Identification

This chapter contains some details about AeroSim Blockset.



Chapter 7: Conclusion



Chapter 8: Further Work and Recommendations



References



Bibliography



Appendix A:

This Appendix contains the initial documentation and the interim report of the project.



Appendix B

This Appendix contains the flight test and simulation results.







1

CHAPTER 1: INTRODUCTION





1.3 Modifications to the project aims



Initially it was planned to use Merlin Flight Simulator for simulation and modelling

purpose but due to some reason, which are discussed later in the report, this was

changed to AeroSim Blockset. This had a major effect on the aims that the project

had initially set to in regards to simulations.









2

CHAPTER 2: LITERATURE REVIEW





CHAPTER 2: LITERATURE REVIEW

2.1 Unmanned Arial Vehicles



2.1.1 Introduction



An Unmanned Arial Vehicles (or UAV), also known as a drone, is an aircraft without

a human operator on board (MSN Encarta c. 2008). UAVs are different that guided

missile or cruise missiles in that the air vehicle is designed to come back and be re-

used. These are also different from normal remote controlled aircrafts in that they

have a high technology control systems on board which means can operate out of

line of sight and at altitudes where person on the ground cannot readily see them.

These air vehicles still need a pilot or an operator who rather than being seated in

the aircraft itself is located in a control centre normally referred to as a Ground

Control Station. (UAVSA c. 2008).



2.1.2 Types of UAVs



2.1.2.1 Classification by Aircraft Configuration



In general an aircraft is any flying machine/vehicle in all possible configuration be it

fixed-wing, rotary-wing, a balloon or an airship and potentially any aircraft can be

converted into an UAV with the right technology and control systems installed on

board (Beggs 2009). Therefore one of the ways classifying different types of UAVs is

by type of aircraft configuration.



a) Fixed wing UAV



These are the most common types

of UAVs and are currently being

used for wide range of

applications. These can be of

different sizes like the big Northrop

Grumman Global Hawk with a

wing span of 39.9m (Northrop

Grumman 2007a) to the small

backpack Casper form Becker

Avionics with a wing span of just

2.5 m (Becker Avionics 2006).

Some examples of different size

and range fixed wing UAVs can be

seen in figure 2.1a



One of the reasons for the

success of fixed wing UAVs is that

these are quite stable and require Figure 2.1a Examples of some fixed wing UAVs (BBC

simpler systems to control News 2009)

compared to other configurations.







3

CHAPTER 2: LITERATURE REVIEW







b) Rotary-wing UAVs



There has been a lot of development in rotary-wing UAVs in recent years. The

manoeuvrability and the ability to maintain the aircraft in hovering of a Rotary wing

UAVs or a helicopter UAV present several advantages for UAV applications.

However, rotary-wing aircrafts are very unstable and therefore more difficult to

control and require the application of reliable control laws. (Remub et al. 2007:111)









Northrop Grumman MQ-8B Fire Scout is an A-160 Hummingbird by Boeing/Frontier

advanced rotary-wing UAV (US OSD 2005)

(Northrop Grumman 2007)

Figure 2.1b Examples of Rotary-wing UAVs.



c) Airship UAVs



A number of unmanned airship projects, both free-flying and tethered (aerostats),

have been initiated to provide synergistic capabilities to those provided by unmanned

aircraft, most notably extended persistence. There appears to be potential for

synergy between airships and UAS that enhance capability or reduce cost in several

mission applications including force protection, signals intelligence collection,

communications relay and navigation enhancement. An airship UAV’s most

significant challenge appears to be limited mobility. (US OSD 2005:32)



Example of some Airship UAVs can be seen in Figure 2.1c









Advanced Airship Flying Laboratory by American Tethered Aerostat Radar System (TARS) by ILC

Blimp Corporation Dover

Figure 2.1c Types of UAVs (US OSD 2005)









4

CHAPTER 2: LITERATURE REVIEW





2.1.2.2 Classification by Autonomy



Based on the autonomy of the flight control system the UAVs can be categorised into

three main levels:



Level 1: no autonomy on-board the aircraft. This will be more like a remote controlled

aircraft (similar to a hobby plane). However different systems on-board the aircraft

like sensors, cameras, GPS receivers and transmitters can be used to assist the on

ground operator to fly the air craft out of sight.

Level 2: semi-autonomous aircraft with autopilot on-board to keep the aircraft stable.

Difficult tasks like landing and takeoff will still be carried out remotely by a human

pilot

Level 3: fully-autonomous aircraft with onboard flight management system that can

manage the whole set operation (including takeoff and landing) once the mission is

uploaded.



These levels of autonomy are only related to the basic flying capabilities of the UAV

like take off, landing, cruse, some navigation and not to any other autonomous

function that a UAV might be required like tracking objects, object recognition,

collision avoidance etc. Autonomy of the aircraft has been discussed in detail in the

section 2.2.



2.1.3 Components of a UAV System



A UAV system can be divided into three main components. These will be the UAV

platform, the ground station and the payload (UAVSA c. 2008). These have been

discussed individually below.









Fig. 2.1c Components of a UAV system.



2.1.3.1 UAV Platform



The UAV Platform itself will consist of the following components/systems:



a) The airframe



As mentioned earlier the airframe of a UAV can be of any configuration i.e. fixed-

wing, rotary-wing etc. Like any conventional aircraft the airframe must have the

required aerodynamic properties, be light weight and must be able to sustain the

specified loads for the different application.



5

CHAPTER 2: LITERATURE REVIEW







b) The propulsion system



The type of propulsion system used within a UAV will depend on the type of aircraft

and task requirements.



c) Flight control System.



The flight control system (FCS) is the most important system within the UAV. The

system is connected to different types of sensors (gyroscopes, pressure sensors),

navigations systems and avoidance systems. Complexity of the FCS again depends

on the UAV application.



2.1.3.2 Payload



The UAV may be required to carry different types of payloads. One of the most

common payloads is a camera or an optical sensing system. This is usually used by

the operator on the ground station to see were the UAV is going or look at particular

targets. Other payloads can be infrared cameras, radiation detectors, air sampling

systems etc. Military UAVs may have munitions, radars, scanners etc.



2.1.3.3 Ground Control System or Station



At the ground control station the operator controls or monitors the UAV. The ground

station will therefore have avionics flight display, navigation systems, Position

Mapping system, system health monitoring. The Ground Station will also have some

kind of manual control devices like joysticks to control the aircraft. (UAVSA c. 2008)



The Ground Control station will also have system to receive data from the UAV like

video, photographs, etc depending on the onboard systems



2.1.4 Applications



Unmanned Arial Vehicles (UAVs) have seen unprecedented levels of growth in

military and civilian applications domains. UAV applications are usually referred to as

3D or D3, ‘dull, dirty and/or dangerous’. The primary applications identified and used

to date all involve putting the UAV and its payload in environments where the pilot in

a manned operation might be significantly at risk of losing his life or dying of

boredom. Currently the UAV applications are mostly defence related and main

investments are driven by future military scenarios. Today the civilian UAV market is

small compared to the military one. Significant civil markets for UAVs are still to

emerge, with only limited niche applications being currently available. However, in

the next 10-15 years, the expectations for the market growth of civil and commercial

aerial robotics are very high. (Ollero and Manza 2007:3)



There is also a cost justification for using UAVs. They can have longer operational

duration: they can require less maintenance: they can be cheaper on fuel to operate:

they can be operated remotely and sometimes autonomously carrying out the

mission with the minimum of human intervention and supervision: and they can be

deployed in a number of different terrains and are not always dependent on prepared





6

CHAPTER 2: LITERATURE REVIEW





runways. Some argue that the use of UAVs in the future will be a more responsible

approach to certain airspace operations from an environmental, ecological and

human risk perspective (UAVSA c. 2008).



Below are some of the examples of UAV applications taken from UAVS website.



Aerial Policeman and Crowd Monitoring

Aerial Reconnaissance

Aerial Traffic and Security Watch

Air to Air Missiles, Air to Ground Missiles, Anti-Tank Missiles

Battlefield Management

Crop Dusting, Crop Management

Disaster damage estimation, Disaster effects management

Fire Fighting

Fishery Protection, Forestry

Geophysical surveys

Guided Shells

Life raft Deployment

Litter on beaches and in parks

Maritime and Mountain Search and Rescue

Mineral exploration

Oil and Gas Exploration and Production

Oil and gas pipeline

Pollution Control and Air Sampling

Search and Rescue

Telecoms relay and signal coverage survey

Waterways and shipping

Wide Area Munitions Deployments









7

CHAPTER 2: LITERATURE REVIEW





2.2 Stability and Automation of UAVs



Need for taking control out of the human hands and putting it under some sort of

automatic control has been there since a long time in aviation history. The reason

being that of itself, the path of any aircraft is never stable and aircrafts only neutral

stability in heading. Without control, aircraft tend to fly in a constant turn. In order to

fly a straight and level course continuously-controlling corrections must be made

(McLean 1990). For the human pilot this can be very exhausting and therefore there

is a need for some sort of automatic flight control system (AFCS). In an Unmanned

the need for having some sort of stability devices and AFCS is therefore quite

obvious because an operator on ground will not be able to provide the necessary

control correction will be very difficult.



As mentioned in the previous section UAV can be dived into different categories

based on autonomy they have. This section will have a bit more detail into how

stability and autonomy of UAVs.



a) Stability of un-autonomous UAVs.



An un-autonomous UAV can simply be called a remote control aircraft or a hobby

plane. Some people will argue that such an aircraft cannot be categorised as a UAV

as mentioned section 2.1. The stability of such an aircraft will depend more on the

aerodynamic stability of the airframe. Such stability can be achieved by using

conventional methods like using a dihedral wing for roll stability and positioning the

centre of mass on front of aerodynamic centre for longitudinal stability (Kermode

2006). The ground operators will thus be responsible for manoeuvres and provide

corrections from time to time. The problem in such an aircraft will be that the

increase in aerodynamic stability will mean decrease in manoeuvrability.



b) Stability of semi-autonomous UAVs



In a semi-autonomous UAV the roll of operator is limited to manoeuvres lonely.

Flying the aircraft will be more like playing a video game where the operator can

move around using a joystick and does not have to worry about stabilising or

providing any control corrections. An onboard computer or an autopilot will to this

job. Apart from the aerodynamic stability methods mentioned in previous section

following methods/devices



Aerodynamic Stability Augmentation System (SAS): This system makes

use of the aerodynamic control surfaces like elevators, ailerons and rudders

to provide improved handling qualities (McLean 1990:10). For example for the

pitch stability will be achieved by applying elevator deflections proportional to

the pitch rate which will provide additional damping. Example of such an

autopilot system will be in Chapter 5. This type of systems will require

gyroscopes to record the changes and provide feedback to the autopilot.



Non-Aerodynamic Stability Augmentation Systems: Non-aerodynamic

augmentation devices are used mostly for small and miniature UAVs. Such

devices are used because adverse meteorological conditions generally affect

smaller aircraft more strongly than they affect larger aircraft and there is no





8

CHAPTER 2: LITERATURE REVIEW





known way to create controlled aerodynamic forces sufficient to counteract

the uncontrollable meteorological forces on miniature aircraft. Such systems

can use devices like telescopic shafts with a mass pod or counter weight at

the end. The telescoping shaft and mass pod are stowed in the rear of the

aircraft. When deployed, they extend below the aircraft. (Langley Research

Centre 2005) A similar example of such a system can be of the long rod or

shaft that a funambulist uses while tightrope walking to balance himself.



c) Fully autonomous UAVs



A fully autonomous UAV will have AFCS or autopilot that completely replaces the

human operator in the control of the aircraft. Such AFCS will be capable of take off,

landing, following a navigation path and depending on the specification able to

perform non-aggressive and aggressive manoeuvres. The components and sensors

with fully autonomous UAV will include gyroscopes, pressure sensors, GPS

navigations system, collision avoidance system and electronic compass. The aircraft

will uses similar methods of stability as mentioned earlier.



Table 2.1 shows a list of commercially available systems autopilot system for UAVs.



Table 2.1 List of Commercially Available Autopilots (UAS Research 2008)

Company Autopilot Models Used on website

A Level Aerosystems (Russia) Autopilot A Level Aerosystems, Russia www.zala.aero



RQ-2A/B Pioneer (Pioneer Inc., USA)

MIAG BQM-74 (Northrop Grumman, USA)

BAE Systems (USA) www.baesystems.com

NSU CL327 (Bombardier, Canada)

Mirach100/5E (Galileo Avionica, Italy)

Curtiss Wright - Vista Controls

Global Hawk (Northrop Grumman, USA) www.cwfc.com

Vista Controls Corp (USA) IMMC

Autopilot I Cabure, Yagua (Nostromo, Argentina)

Mavionics (Germany) www.mavionics.de

Autopilot II Yarara (Nostromo, Argentina)



Scarab (SCR, Spain)

X-Vision (SCR, Spain)

Boomerang (BlueBird Aero, Israel)

MicroPilot (Canada) MP2028 www.micropilot.com

Blueye (BlueBird Aero, Israel)

ALBA (INTA, Spain)

Casper (Becker Avionics, Israel)

Rockwell Collins, Inc (USA) G-311 Sky-X (Aliena Aeronautica, Italy) www.rockwellcollins.com

Selex Sensors & AS (UK) Selex FCS Phoenix (BAE Systems, UK) www.selex-sas.com

Scorpio (EADS, France)

Copter I (SurveyCopter, France)

APID (CybAero, Sweden)

wePILOT 1000

DRAC (EADS, France)

weControl (Switzerland) wePILOT 2000 www.wecontrol.ch

DVF 2000 (SurveyCopter, France)

wePILOT4RMAX

Skeldar (Saab, Sweden)

Tracker (EADS, France)

RMAX (Yamaha, Japan)









9

CHAPTER 2: LITERATURE REVIEW





2.3 Dynamics of Flight



2.3.1 Introduction



In the previous section it was said that the reason why Autonomous Flight Control

Systems were used in aircrafts was to keep the aircraft stable and under control.

This section is gives some background information about to flight dynamics as it is

directly related to control an stability of a aircraft and thus links up with the

discussion about the autonomous flight controls



2.3.2 Six Degrees of Freedom (6DOF)



An aircraft has got six degrees of freedom in other words it can move in three

directions along three axes (up/down, forward, backward, lift, right) and rotate in

three directions around the three axis (pitch, roll and yaw).Figure 2.3a shows the

6DOF in a body axis system and also shows the conventional nomenclature for

different forces, velocities and moments.









Figure 2.3a Six degrees of freedom of an aircraft in body axis system

(McLean 1990:17)



Stability or the lack of it is a property of an equilibrium state. The equilibrium is stable

if, when the body is slightly disturbed in any of its degrees of freedom, it returns

ultimately to its initial state. An aircraft which may be stable with respect to one

degree of freedom but unstable with respect to another (Etkin 1996). Therefore

based on the inherent stability of the aircraft and AFCS does not to control all the

degrees of freedom. And for this reason autopilots used on an aircrafts can be one-

axis, two-axis or three axes.



2.3.3 Pitch dynamics and Longitudinal Stability



One of the aims set for the project was to look into pitch control of the UAV and

therefore it is important to give some brief background to pitch dynamics. The pitch

of the aircraft is controlled by the elevators. Any deflection on the elevator will

change the pitch of the aircraft. The aircraft usually oscillates at this point before





10

CHAPTER 2: LITERATURE REVIEW





settling on the new pitch angle. The change in pitch can also be induced by

activation of high lift devices like flaps, movement of centre of gravity or external

forces and turbulence. There are types of oscillation around the longitudinal axis.



a) Short Period Pitching Oscillations



The short period pitching oscillations is a damped oscillation about the pitch

axis. Whenever the aircraft is disturbed from its pitch equilibrium the mode is

excited ad manifested itself as an oscillation in which the principal variables

are pitch rate and angle of attack. Typically the frequency of the mode is 0.5

to 2 Hz. In manned aircraft, this is in the region of a human pilot natural

frequency, therefore it is essential that the short period mode should be well

damped, otherwise severe handling problems can arise (NFTC 2007:22). For

computer controlling a UAV will usually be capable to handle a higher

frequency but it still needs to be damped as it will damage the onboard

systems or payload. It is the short period oscillation which recovers the angle

of attack to its trim value, and this happens sufficiently quickly that the speed

remains substantially constant.



b) Long Period Pitch Oscillations



The long period pitch oscillations, also known as phugoid oscillations, is the

most commonly seen as a lightly damped low frequency oscillation in speed,

which couples with height. Whenever the aircraft is disturbed from trim speed,

the mode manifests itself as a sinusoidal oscillation in which the principal

variables are pitch attitude and speed changes. A significant feature of the

mode is the angle of attack remains substantially constant throughout. Thus

the change in pitch attitude gives a corresponding change in flight path angle,

and hence the height excursions. The period is long, typically in the band of

40 to 100 seconds, and the damping mainly due to the rate of change of drag

of the aircraft whit speed change. I is possible to deduce that the period of the

mode is determined most entirely by the datum speed, and a good

approximation is that the period is seconds is equal to 0.25 of the true

airspeed in knots (NFTC 2007:23). Since the phugoid mode has such a low

frequency, it poses an undemanding task, and an AFCS can control the mode

even when it is unstable. The phugoid manifests itself as a trimming problem,

which, although not regarded as hazardous when poorly damped however it

will hinder the UAV applications like taking images, sensing or tracking a

target.









11

CHAPTER 2: LITERATURE REVIEW





2.4 Modelling and Simulation



2.4.1 Introduction



Modelling and simulations are one of the most important parts of any control system

design and integration. This section gives some background information about

modelling and simulation and how it can be used for UAV systems.



2.4.2 Modelling and Simulation techniques



In order to understand the behaviour of a system, mathematical models are needed.

These models are equations which describe the relationship between the inputs and

output of a system. The basis for any mathematical model is provided by the

fundamental physical laws that govern the behaviour of that system (Bolton

2003:185). For an aircraft the basis of the model will be the relationship between

different Newton’s Laws and Aerodynamic laws that define the motion of an aircraft.



As said in the previous section an aircraft has got six degrees of freedom. This

makes the mathematical model of the aircraft very complex and will take a lot of time

and effort to put all the relationships together. It is therefore important to set of

conditions and assumptions which will define the boundary of the system. For

example with the mathematical modelling of the aircraft a simpler model can be

made by considering only three degrees of freedom or even just two degrees of

freedom. This would make the equations much simpler.



Another important thing to know in modelling is that the equations will include

different constant values or coefficients which are set for the physical system. These

coefficients are needed to be determined for the model to represent the true system.

For example with a simple spring mass model it is important to know the spring

coefficient and the mass for the model to truly represent the system. For an aircraft

these can be different aerodynamic coefficient like lift coefficient, drag coefficient etc.



These coefficients may be determined by doing measurements and calculations on

the actual system, by experimentation or even by simulations that used a different

set of data. For an aircraft this might mean doing wind tunnel tests or CFD tests.



Simulation is the process in which a range of inputs are put through the

mathematical model and the outputs would show the behaviour of the system. Once

the model has been verified it can be used for designing the controller and for

predicting the actual model.



Modelling and simulations are usually done with aid of computer packages. Table

2.4a lists some of the modelling tools that are available for aerospace applications.



2.3.3 Applications



As mentioned in the beginning modelling and simulations are a very important part of

control system designs. These can also be used to investigation behaviour of

systems for optimisation or proving a new concept without risking a real system.







12

CHAPTER 2: LITERATURE REVIEW





Table 2. List of Flight Modelling and Simulation tools

Package Description

Merlin Flight Simulator Commercially available flight simulator that enables

the user to configure their own aircraft models for

simulation.

X-plane This is a flight simulator package which enables

users to configure their own aircrafts. This program

can run on and PC

JSB Sim This is another flight simulator package with user

definable aircrafts. It’s an open source software and

therefore will enable to the user to make changes

and even change the working of the simulations

YS Sim This is another flight simulator package with user

definable aircrafts. It’s an open source software and

therefore will enable to the user to make changes

and even change the working of the simulations

Matlab This is a very powerful mathematical computational

package which is widely used for modelling and

control related applications

Simulink Part of Matlab this package enables modelling a

system with the help of GUI blocks

AeroSim Blockset This package working using Simulink and is

designed for aerospace applications and modelling.

Aerospace Blockset This package working using Simulink and is

designed for aerospace applications.





2.3.4 Problems with modelling



A model is defined by assumptions about the real system and therefore can never be

hundred percent accurate. These assumptions can also include the different

coefficients used for the modelling and without the right values the model will be way

off form the real system. In order to get more accurate results a more complex model

will be required. The problems in doing so will be that a complex model will require

more computation and might cause delay when used in control systems.









13

CHAPTER 2: LITERATURE REVIEW





2.5 System Identification and control



2.5.1 Introduction



System Identification is the a method of developing a model from a real system in

which tests are used to determine the response from the system to some input, e.g.

a step input and then finding a model that fits the response (Bolton 2003:240).



2.5.2 System Identification tools



Different software packages can be used for system identification some of these are

listed in Table 2.5a

Table 2a. List of System Identification Software packages

Package Description

Matlab A very powerful computational tool with may system

identification functions

Simulink Part of Matlab this package enables modelling a

system with the help of GUI blocks

System Identification Toolbox This is a Matlab/Simulink model used for system

identification

SIDPAC This is a Simulink block set used specifically for

aircraft system identification.



These tools can be used to analysis the outputs for the system on step-response

plots, bode plots and root locus plots.









14

CHAPTER 3: UAV PLATFORM





CHAPTER 3: UAV PLATFORM

3.1 Introduction



There were two UAV platforms that were planned to be used for this project. One

was built as a test plane for 2008 UAV built projects and the second one was to be

built for the 2009 UAV projects. The second one was to be constructed with the help

of other students working on other aspects of UAV project.



3.2 Test Plane



The test plane is a high wing Clipped Wing Taylorcraft ARF model aircraft. The

aircraft had been chosen for its stability and enough space for the payload (Castle

2008:37). The test plane had been flown by the 2008 UAV Project students using

remote control and therefore aim was to use the test plane for the testing of autopilot

and initial modelling for 2009 UAV projects as well.









Figure 3.2a Top Gun Clipped Wing Taylorcraft from Hanger-

9 (Hanger-9 2008)





3.2.1 The Airframe



The dimensions of the airframe are given in the table below.



Table: Speciation of the Test Plane

Wing span 1.07 m

Wing Area 0.428 m2

Length 1.485 m

Weight 6 kg approx



3.2.2 Propulsion Unit and Speed Controller



The aircraft uses an ‘AXi 5330/18 Gold Line’ electric motor with radial mounted

propeller holder (see figure 3.2b). The motor uses two FlightPower EON28 11.1 LiPo

batteries. The output is controlled through a Jeti ADVANCE 90 plus controller.









15

CHAPTER 3: UAV PLATFORM









Figure 3.2b (Model Motors 2006)



Table 3.2a

AXi 5330/18 Gold Line

Specification (Model Motors 2006)



No. of cells max 32

max. 10s Li-Poly



RPM/V 259 RMP/V



Max. efficiency 90%



Max. efficiency current 25 - 60 A (>85%)



No load current / 10 V 2A



Current capacity 75 A/60 s



Internal Resistance 32 m



Dimensions (Diameter x Length) 63 x 64 mm



Shaft diameter 8 mm



Weight with cables 652 g









16

CHAPTER 3: UAV PLATFORM









Table 3.2a

Jeti ADVANCE 90 plus controller Specifications

(Jeti 2005)

Dimensions: 65 x 55 x 17 mm

Weight: 75/90 g

Continuous current: 90 A

Accu NiXX / LiXX: 14-32 / 5-10

Voltage 15 – 42 V

Figure: 3.2c Jeti Advance 90 plus speed

controller.







3.2.3 Control system



PCM9X RS10DS.

The aircraft is manually controlled by PCM ii Transmitter via RS10DS The aircraft

has got four servos which control the ailerons, elevators and rudder.









JR PCM9X ii Transmitter JR RS10DS Receiver

Figure: Manual control unit



MicroPilot

The aircraft is autonomously controlled by Micro ilot MP2028g autopilot. Details

about the autopilot are given in Chapter 4.



3.2.4 Power supplies



The aircraft has got separate power supply autopilot, servos and the motor.



3.2.5 Work done on test plane



The test plane had been assemble by the 2008 Project students but there were

asks

some of the tasks required to make the aircraft airworthy



• systems.

Installation of remote control receiver, autopilot and other systems

• Measurement of the aircraft for modelling and simulation.









17

CHAPTER 3: UAV PLATFORM





3.3 UAV 2009 Platform



3.3.1 The Airframe



Figure 3.3a below show the dimensions for the aircraft. The airframe was designed

by other students working on the UAV project. The aircraft was still under

construction at the time of this report being written.









Figure 3.3a Pheonix 09 UAV designed by M. E .Bahrami









18

CHAPTER 3: UAV PLATFORM









Figure 3.3b UAV fuselage under construction.



3.3.2 Propulsion Unit and Speed Controller



Same as the test plane. See section 3.2.2



3.3.3 Control system



Same as the test plane. See section 3.2.3



3.3.4 Power Supply



Same as the test plane. See section 3.2.4



3.3.5 Other components



An extra servo will be used to unlock and drop the flaps.









19

CHAPTER 4: AUTOPILOT





CHAPTER 4 AUTOPILOT

4.1 Introduction



The autopilot used for the UAV is a MicroPilot MP2028g. The autopilot is capable of

flying the UAV fully autonomously. The autopilot uses gyroscope, air pressure and

GPS as senses for inertia, speed, altitude and position to control the aircraft. During

the project the autopilot been tested on ground but a flight test could not be

achieved.



4.2 Components





The MicroPilot MP2028g autopilot system consists of the following components.



Table 4a: List of components for autopilot system

Component Description



MP2028g CORE









This is the main autopilot board and all the other

components are connected to it.









Figure 4.2a (MicroPilot 2004)



MP2028g AGL









Above Ground Level (AGL) is an ultrasonic altimeter

that provides altitude information to an altitude of

about 4.88m above the ground. It is required for

autonomous takeoff and landing.









Figure 4.2a (MicroPilot 2004)









20

CHAPTER 4: AUTOPILOT





MP-Servo board









The Servo board distributes the servo signal to each

servo









Figure 4.2a (MicroPilot 2004)



MP-ANT









This is the GPS antenna which connects to the

CORE board. The antenna is mounted on a 10cm x

10cm copper board.









Figure 4.2a (MicroPilot 2004)



Radio Modems and MP-COM board

COM









The radio modem connects to the ground station

computer and communicates with the autopilot via

the COM board.









Figure 4.2a



Faraday Cage







The Faraday cage had been designed by 2008 UAV

Project Students to shield the CORE board from any

external interference especially from the motor.







Figure 4.2a









21

CHAPTER 4: AUTOPILOT





Software The software is used to communicate with the

autopilot from the ground station.



MicroPilot Horizon:

This software provides a GUI for configuring the

autopilot and setting up flight path.



Microsoft HyperTerminal:

The HyperTerminal can be used to communicate

with the autopilot. It uses a commend line

setting

interference but will enable to configure more set

and acquire flight data.







4.3 Installation



The autopilot components were installed on the control board. In this section only the

important points to be remembered while installing the MP2028g is mentioned. Full

details of installing MP2028g can be found MicroPilot Autopilot Manual and

Installation DVD.



a) Control Board



All the autopilot components are installed on a single board. The layout of the control

board for the test aircraft is shown in figure 4.3a









Figure 4.3a: Autopilot Board for Test Plane.



b) Servo Board





22

CHAPTER 4: AUTOPILOT





The servo board was connected to the servos for normal setting. This means that

only servos for ailerons, elevators, rudder and throttle were connected. Figure 4.3b

below shows which pins are supposed to be connected to which servo.









Figure 4.3b: Servo Board



4.4 Configuration



The autopilot was configured using the MicroPilot Horizon software. It was

configured for Normal settings and under a fake GPS lock.



The autopilot was then tested on ground for basic servo responses.



4.5 Problems with the autopilot



There were some issues with configuration the autopilot



a) Communication Problem



The autopilot should be able to communicate with the ground station either by using

MicroPilot Horizon or by using Microsoft HyperTerminal. The autopilot was able to

communicate with the Horizon software properly most of the time but it did freeze the

computer while configuring the Rudder setting couple of times. This behaviour

however only happened while using the personal laptop and did not occur when

universities laptop was used. This might have happened have happened due to the

former being too slow.



The main communication problem occurred when HyperTerminal was used to

communicate with the autopilot. The HyperTerminal only communicated once and for

other attempts showed nonsense values on the screen as shown in figure 4.5.



The communication using HyperTerminal is very important to get the flight data for

any further investigation. Most importantly the data is very important for analysis for

selection of proper gains.



23

CHAPTER 4: AUTOPILOT









Figure 4.5a Screenshots of the HyperTerminal data. Top: The data on the HyperTerminal screen

when a proper connection was estabilished. Above: The HyperTerminal data showing nonsense

values.



b) Battery problem:



The autopilot seems to drain the batteries in a very short period of time and this

delayed configuring it. However with the new batteries this did not seem to be a

problem.



The autopilot had some issues with the AGL unit in the 2008 UAV project. However

the AGL seem to respond properly during the ground tests showing the right

distance from ground. It might be possible that the interference from the motor would

have affected the AGL unit in the past.









24

CHAPTER 5: FLIGHT SIMULATION





CHAPTER 5: FLIGHT SIMULATION

5.1 Introduction



The UAV was planned to be simulated using Merlin Flight Simulator present at

Coventry University’s Aerospace Lab. The objective behind doing so was to

understand the stability of the aircraft so that the proper gains for the MicroPilot

MP2028g can be determined without risking the UAV in a real flight test. In order to

do this it was important to understand the working of Merlin Simulator1 and its own

Arthur Autopilot.



5.2 Merlin Flight Simulator



5.2.1 Simulator Choice



There were two flight simulators available for the simulations, Merlin’s MP520 and

MP521. Some of the options available on the two can be seen in Table 5.2a.



Table 5.2a Merlin Flight Simulators present at Coventry University.



Merlin MP520 Merlin MP521

Excalibur I

Aircraft Config. Software Excalibur I

Excalibur II (beta)

Aircraft Systems

Autopilot Arthur

Flight Controls Systems

Motion base actuators Electric Hydraulic









Because no autopilot was present on MP520 it was initially decided to use MP521

for the simulations. However MP520 could still be used if the autopilot was not

needed for the particular flight and if the model was not for Excalibur II format.



5.2.2 Aircraft Configuration Software



There were two aircraft configuration software available with MP521, the Excalibur I

(Ex-I) and Excalibur II (Ex-II). Excalibur I is a stable version and also works on

MP520. However the aircraft model designed using Excalibur I is very simple and it

does not provide options for advance design like multiple section wing, horizontal

and vertical panels.



MP521 had beta version of Excalibur II. This version does provide advance

configuration. During the initial stage of the project Ex-II was used to configure



25

CHAPTER 5: FLIGHT SIMULATION





aircraft models but due to some problem the models did not work or were unstable.

These issues were reported to Merlin. Another problem with Ex-II was that it could

not be installed on any other computer which meant that the aircraft needed to be

configured in lab only. Therefore it was decided to use Ex-II only and keep the

models simple.



5.2.3 Autopilot



The MP521 simulator has software autopilot installed on it called Arthur. Arthur is a

4-axis (roll, pitch, yaw and altitude) autopilot which means it can be used for fixed

wing as well as rotary wing aircrafts. The cockpit controller deflections (from. pitch

and roll stick, Yaw pedals and throttle lever) are mixed with autopilot servo deflection

to provide closed-loop control. (Merlin Products 2007)



5.2.3.1 Control Modes





Arthur provides control using five modes. Figure 5.2a shows the Control Panel inside

the simulator cockpit to control the autopilot. It also shows the backend for Arthur

which shows the current status of the autopilot and can also be used to set gains for

the different modes



1.) Stability Augmentation System (SAS) Modes



The stability augmentation seeks to provide handling qualities in roll, pitch and

yaw by providing additional damping. For example for the pitch stability this is

achieved by applying a control surface deflection proportional to the pitch rate.



It is important to engage the SAS Modes before any other autopilot modes

can be used.



2.) Autopilot (AP) Modes



The AP modes maintain a particular flight parameter. For example for the

Altitude (ATT) mode the autopilot will maintain the aircraft at a specific pitch

altitude. ATT mode will either maintain the current altitude when the mode is

engaged or will move the altitude set in command mode.



There are three modes available under AP mode:

a) Altitude (ATT) mode

b) Wing Leveller (WNG LVL) mode

c) Turn Co-Coordinator (TC) mode









26

CHAPTER 5: FLIGHT SIMULATION









Figure 5.2a Merlin Flight simulator Autopilot: The Flight Control Panel and Arthur backend.





3) Command (CMD) Modes



The CMD modes are used to set the demands for AP mode. For example the

Altitude hold mode will be used to set the required altitude and vertical speed.

The ATT autopilot mode will then try to maintain this altitude.



There are three modes available under CMD mode

a) Heading Hold (HDG) Mode

b) Altitude Hold (ALT) Mode

c) Speed Hold (IAS) Mode



These modes can be engaged only if the related AP modes are engaged first.



4) Navigation (NAV) Mode



Arthur includes two navigation modes for tracking VOR beacons and

instrument landing systems. These modes were not required for this project.









27

CHAPTER 5: FLIGHT SIMULATION





Control Mixing



It is important that the aircraft model has got External

Controls enabled on the system settings of Excalibur

in order for autopilot to engage (see figure 5.2b).



5.3 Flight Simulation Models



In order to understand the working of the flight

pre-built stable model

simulator and Arthur autopilot a pre

of Cessna172 was used. The plan was to modify this

model convert it into the Test Plane model and UAV Figure 5.2b The external Controls

settings must be checked on the

model. Systems settings on the Excalibur

editor for autopilot to function.

One of the issues with the configuring the models

scaled

were the simulator could not run small models and therefore the models were sca

up. Another issue was that Excalibur only as combustion engines as power plant

which means that the total mass of the aircraft will reduce once the consumption of

fuel. One way to overcome this was to use a value of zero for SFC.



5.4 Test Flights



e

The aim of the flight testes was to look into the longitudinal stability of the aircraft.

This meant analysis of the natural short-period oscillations and long- -period (or

Phugoid) oscillations damping of the aircraft and how the autopilot will assist in

further damping.



The tests were done to find the open loop response and close loop response i.e.

when the autopilot was engaged.



5.4.1 Open Loop and Close Loop Response Test



In order to get the open loop response of the aircraft different types of signals were

manually inputted using the control stick.



The closed loop response flight tests were similar to the open loop test the only

these

difference being that the autopilot was switched on for the tests.



One of the main problems encountered during the tests was that a perfect and

repeatable input could not be inputted manually. Another problem for these tests

was that as these were done quite earlier stage in the project getting used to the

ight

flight simulator took some time.



5.4.2 Comparison test



These testers were done in the last stages of the project using Merlin Simulator in

order to see how the different modes available within the autopilot will affect the

ee

stability if flight. For this three flights were conducted. The Cessna 172 model was

used.







28

CHAPTER 5: FLIGHT SIMULATION





a) Autopilot off: For the first test took place in autopilot off. The flight test procedure

is given below



Time (min) Action Comment

00:00 Fly from 609.6m (2000ft) with IAS

129.64 km/h (70 kt)

02:15 Pull stick back for 45 sec Aircraft stalls

03:00 Release stick Wait for aircraft to settle

11:30 Stop. Save as fly1



b) Autopilot on SAS Pitch mode. For this test the autopilot was left on in stability

augmentation mode



Time (min) Action Comment

00:00 Fly from 609.6m (2000ft) with IAS

129.64 km/h (70 kt) SAS mode

engaged

02:30 Pull stick back for 45 sec Aircraft stalls

03:15 Release stick Wait for aircraft to settle

11:45 Stop. Save as fly2



c) Autopilot on in ATT mode. For this test the autopilot was set in ATT mode. The

flight test procedure is given below



Time (min) Action Comment

00:00 Fly from 609.6m (2000ft) with IAS

129.64 km/h (70 kt) ATT mode

engaged

02:15 Pull stick back for 45 sec

03:00 Release stick Wait for aircraft settle

11:30 Stop. Save as fly3



The results for these tests are discussed in next section.



5.5 Results and Analysis



5.5.1 Open Loop and Close Loop Response Analysis



As mentioned section 5.4 these tests were done in the earlier stage of the project.

The full list of test and results can be found in Appendix B.



There was a major problem with these tests because proper input signals could not

be generated and because of the unfamiliarity with the M521 keeping the aircraft in a

straight path was found to be very difficult.









29

CHAPTER 5: FLIGHT SIMULATION





30

Elv Angle

Pitch Angle

X: 43

Y: 20.9

X: 61

20

Y: 17.15









10









0





X: 33

Y: -9.31



-10









-20





X: 28

Y: -28.61



-30

0 10 20 30 40 50 60 70 80 90 100



Figure : Pitch response for a impulse elevator deflection



5.5.2 Comparison test analysis.



5.5.2c

Figure 5.5.2a, 5.5.2b and 5.5.2c show the results from the comparison test in No

. differences

Autopilot Mode, SAS Pitch Mode and AP ATT Mode respectively. The differ

between the three are quite clear from these plots.









5.5.2a:

Figure 5.5.2a Results for the flight without Autopilot.







30

CHAPTER 5: FLIGHT SIMULATION









Figure 5.5.2b: Aircraft flight in SAS Autopilot mode.









Figure 5.5.2c: Aircraft flight in ATT Autopilot mode.







31

CHAPTER 5: FLIGHT SIMULATION





Without the autopilot the elevator deflection looks almost like a square signal which

is maintained at a constant value till the control stick is released. Comparing this with

possible

the SAS Pitch mode plot, it is possible to see deflections even when the control stick

has been held in set position. This is even more visible in the third test when the ATT

mode was engaged on the autopilot. Another difference between the three is the

amplitude and frequency of oscillations in altitude plot of the three tests. The values

for these are given in table 5.5a





Table 5.5a : Results analysis of comparison flight









Control Stick Pulled



No. of Frequency

Amp1 oscillations t1 ω (rad/s) T (sec)

Fly 1 50.5367 3.020134 14.9 0.42169 45

Fly 2 80.8 2.472527 18.2 0.34523 45

Fly 3 48.7 3.020134 14.9 0.42169 45





Control Stick Released

No. of Frequency

Amp2 oscillations t2 ω (rad/s) Ts (sec)

Fly 1 48.6 11 21.1 0.297781 232.1

Fly 2 49.6 10 21 0.299199 210

Fly 3 4.3 5 22.6 0.278017 113





Figure 5.5.2d . Cmparison Test analyis





5.6 Conclusion



There wasn’t much analysis done one the data from the flight simulations because

most of these test were done on C172 model in order to get used to the simulator

and for the actual UAVs the data would be quite different. The results were however

recorded and some examples can be seen in the Appendix B. This was done at an

early stage of the project and it was found that the input signals were making the

aircraft unstable. It was also for that the data was difficult to analyse as the results

were not the perfect step responses which were shown on text books. At that point it

was thought that may be a different package could be used to simul simulate to have more

control over the simulation.









32

CHAPTER 6: SYSTEM IDENTIFICATION





CHAPTER 6: SYSTEM IDENTIFICATION

6.1 Introduction



In order to get more controlled modelling and simulation different options for system

identification tool were researched. Based on the research done U-Dynamics

AeroSim Block set seemed to be a good option to use for both simulation and

system identification.



6.2 Reasons for choosing AeroSim Blockset



The AeroSim seemed to be a very attractive package for modelling and simulation

part of the project for the following reasons:



• AeroSim offered a wide range of complete aircraft models for Simple up to

6DOF Aircraft models (U-dynamics 2008)

• AeroSim could be used on any PC with Matlab/Simulink installed on it. (U-

dynamics 2008). This was very attractive as it meant the data can be

analysed straight after the simulation was done.

• AeroSim offered Visual output to FlightGear Flight Simulator and Microsoft

Flight to simulator. (U-dynamics 2008) The block also included a Cessna 172

model for FlightGear demo. This seemed to be a good feature as same

model had been tested on Merlin Flight Simulator.

• From the research done and looking into different journal articles and

conference papers it was found that AeroSim blockset was used for many

similar projects.

• The blockset was free for Academic and Educational purposes. (U-dynamics

2008)



Based on the above features offered by AeroSim blockset decision to move the

simulations from MP521 to AeroSim for system identification was taken.



6.2 Aircraft model configuration problem with AeroSim



This was the main problem with using the blockset. The aircraft configuration model

for AeroSim was very complex compared to the models used previously. It required

the many aerodynamic coefficients which were not used for any of the previous

models and therefore were not know. For example the Lift coefficient as a sum of

many other coefficients as shown in the equation below.









To determine the coefficients required much deeper understanding of aircraft

aerodynamics. The other problem was that to derive these coefficients manually

would take a lot of time and would therefore shift the whole aim of the project.







33

CHAPTER 6: SYSTEM IDENTIFICATION





The block model for the Cessna 172 was completed even the aircraft configuration

was not complete. Figure 6.2a and Figure 6.2b









Figure 6.2a Simulink model designed for C172 using AeroSim Blockset.









Figure 6.2b Response for running the Simulink model









34

CHAPTER 6: SYSTEM IDENTIFICATION







6.3 DDATCOM software package



computational

Research was done to find some kind of computational tool to derive the coefficient.

A software package called DDATCOM was found to be used in some projects that

e coefficients.

could give these aerodynamic coefficients. Data compendium (DATCOM) had been

developed by United States Air Force (USAF) and contained a large collection of

information containing of classical aerodynamics and analysis and experimental

2007).

data. (Jung and Tsiotras 2007) DDATCOM or DigitalDATCOM is a computer

database of this information and uses it on to the aircraft model to determine the

aerodynamic coefficients.



6.3.1 DATCOM modelling



DATCOM used a different set of perimeter for aircraft configuration. In particular it

required coordinates for the shape of the aircraft. In order to do so measurements

were taken from C172 photograph. This can be seen in figure 6.3a.









:

Figure 6.3a: Measurement taken from Cessna 172 photograph (EuroControl, c. 2009) for

DDATCOM.



After taken the measurements data was put into the DDATCOM aircraft configuration

file. Based on this data DDATCOM produced a 3d model of the aircraft as seen in

figure 6.3b



Despite the 3d model looking alright there were some problems within the

configuration which caused error and the results for the model could not be accrued.

The screen shot of the output file are shown in figure 6.3c









35

CHAPTER 6: SYSTEM IDENTIFICATION









Figure 6.3b: DATCom model for Cessna 172









Figure 6.3c Output file from DDATCOM







It wasn’t possible to resolve these errors in the due time. DDATCOM did plot some

graphs which can be found in Appendix B.







36

CHAPTER 6: SYSTEM IDENTIFICATION







6.4 Flight Gear simulation problem



The AeroSim blockset contained an example of a C172 model that would simulate in

Flight gear package, see figure 6.4a. The problem was that the C172 model was

actually in flight gear and therefore could not be used for any other analysis. Also

problems were encountered while trying to use this example. Example can be seen

in 6.4b.









Figure 6.4a C172 model simulation in Flight Gear









Figure 6.4b Error while trying to run Flight gear with AeroSim.







37

CHAPTER 6: SYSTEM IDENTIFICATION







6.5 Conclusion



As can be seen from the previous sections the experience with using the AeroSim

did not go very well and no system identification analysis was done unfortunately.

The models and configuration files can be found in the CD attached with this report.









38

CHAPTER 7: CONCLUSION





CHAPTER 7: CONCLUSION

The aim of this project was to implement and understand the working of MP2028 and

to model and simulate the aircraft and the autopilot. Even though the project did not

go as planned the following can be listed as the achievements or the positive points

of the project.



• Better understanding of aircraft control systems.

• Familiarisation and implementation of the MP2028g autopilot

• Better understanding of working of Merlin Flight simulator

• Knowledge of different packages available for simulation.



However there are some things that the project did not achieve.



• The simulations did not work as planned specially with AeroSim Blockset.

This also ended up in lack of analysis.

• A linearised model of the pitch dynamics was not designed.

• A real flight test did not take place and therefore no real data could be

acquired for further analysis.



The move to use AeroSim Blockset made the simulation side of the project more

complicated. Also not getting to fly the test plane according to plan was also a de-

motivation. If flown the data from the aircraft would have been good for comparison

for simulations and broadened the analysis. There was a very useful knowledge

gained during the project though and therefore if the project was run again the use of

AeroSim Blockset will still be considered but this time he models would be designed

specifically for the blockset rather than adapting or converting the models for other

packages.









39

CHAPTER 8: FURTHER W ORK AND RECOMMENDATIONS





CHAPTER 8: FURTHER WORK AND RECOMMENDATIONS

There is a lot of potential work for continuing and improving all aspects of this

project.



The autopilot has not been used in a real flight till now and therefore the full potential

of the autopilot has not been tested till date. Therefore there is still some work that

can be done in this area.



As seen in the report the major problems were related to simulations. It would be

recommended to install Matlab/Simulink on the Merlin Simulators. This can be used

for more controlled simulations and analysis of aircraft models. It might be possible

to integrate the models with AeroSim Blockset.



All the open source and freeware software like DDATCOM, Flight Gear, and

AeroSim has been included in the project and would help further work related to a

similar project.









40

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