Unmanned Aerial Vehicle (UAV)

94 Pages·2015·11.02 MB·English

by  Andre C. Marta

Raspberry Drone: Unmanned Aerial Vehicle (UAV)
Guilherme Lereno Santos Vale
Thesis to obtain the Master of Science Degree in
Telecommunications and Information Engineering
Supervisors: Prof. Nuno Filipe Valentim Roma and Prof. Ricardo Jorge Fernandes
Chaves
Examination Committee
Chairperson: Prof. Paulo Jorge Pires Ferreira
Supervisor: Prof. Nuno Filipe Valentim Roma
Member of the Committee: Prof. Alberto Manuel Ramos da Cunha
May 2015
ii
Acknowledgments
IwouldliketothankProfessorNunoRomaandProfessorRicardoChavesforgivingmetheopportunity
toworkundertheirsupervisionandtheywerealwaysavailabletohelpmethroughouttheentireproject.
iii
iv
Resumo
Estatesefoca-senodesenvolvimentoeimplementac¸a˜odeummo´dulocomputacionalnumunmanned
aerialvehicle(UAV)baseadonumminicomputadordebaixocusto. Estemo´dulointeragecomaestac¸a˜o
terrestre, de maneira a transmitir a informac¸a˜o obtida de um conjunto de sensores (GPS, imagem e
outrossensoresdoUAV).Naestac¸a˜oterrestre,ascoordenadasdeGPSsa˜osubsequentementeusadas
para trac¸ar a trajeto´ria num mapa baseado em Google Maps, embebendo a informac¸a˜o dos sensores
no mapa. A estac¸a˜o mo´vel foi desenvolvida em linguagem de programac¸a˜o C no mini computador
Raspberry Pi com uma distribuic¸a˜o de Linux. A estac¸a˜o mo´vel captura de imagens com uma webcam
pronta a usar e usa um GPS convencional para adquirir a latitude/longitude. A informac¸a˜o adquirida
e´ enta˜o subsequentemente enviada para a estac¸a˜o terrestre atrave´s de um link de comunicac¸a˜o WiFi
sem fios. A estac¸a˜o terrestre e´ composta por uma aplicac¸a˜o web, desenvolvida em Node.Js, com
umainterfacegra´ficaquemostra(emtemporeal)atrajeto´riadoUAVeinsereainformac¸a˜odosdados
dossensoreseimagensdevidamentegeorreferenciadoscommarcadoresnomapa. Deacordocoma
avaliac¸a˜odedesempenhorealizada,aimplementac¸a˜odosistemapreencheosrequisitos,sendocapaz
deoferecerumataxadetransfereˆnciade4imagensporsegundo.
Palavras-chave:
UnmannedAerialVehicle,SistemaEmbebido,MiniComputador,Aquisic¸a˜o
eCodificac¸a˜odeImagem,Aquisic¸a˜odeSinaisdeGeorreferenciac¸a˜o,InterfaceGra´fica.
v
vi
Abstract
This thesis focuses on the development and implementation of an on-board computing module in an
unmannedaerialvehicle(UAV)basedonalow-costsingle-boardcomputer. Thismoduleinteractswith
a base station, in order to transmit the data gathered in a set of sensors (GPS, image and other UAV
sensors). At the base station, the GPS coordinates are subsequently used to track the trajectory in an
user interface based on Google Maps, embedding the sensors data on the map. The mobile station
was developed using C programming language on a Raspberry Pi single board computer with Linux
distribution. It captures images with an off-the-shelf low-cost webcam and uses a conventional GPS
moduletoacquirethelatitude/longitude. Theacquireddataisthensubsequentlysenttothebasestation
throwawirelessWiFicommunicationlink. Thebasestationiscomposedofawebapplication,developed
in Node.Js, with a graphical interface to show (in real time) the trajectory of the UAV, by embedding
the georeferenced sensors data and images with convenient markers on the map. According to the
conducted performance evaluation, the implemented system is able to fulfil the aimed requirements,
beingabletoofferanimageacquisitionthroughputof4fps.
Keywords:
Unmanned Aerial Vehicle, Embedded System, Single-Board computer, Image ac-
quisitionandencoding,Georeferencesignalacquisition,GraphicalInterface.
vii
viii
Contents
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Resumo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
ListofTables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
ListofFigures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
1 Introduction 1
1.1 Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 RelatedWorkandTechnologies 4
2.1 ExistingSolutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1 FPVVideoSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.2 Video/TelemetryTransmissionSystems . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.3 ExistingSolutionsDiscussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 RelevantTechnology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.1 ProcessingBoards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2.2 VideoAcquisitionSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.3 GPSSystems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2.4 DataCommunication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.5 DataVisualisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3 SystemArchitecture 20
3.1 OverallSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2 MobileStation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.2.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2.2 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.3 BaseStation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
ix
4 SystemIntegrationandImplementation 36
4.1 MobileStation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.1.1 OperatingSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.1.2 ImageAcquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.1.3 ImageEncode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.1.4 ImplementationoftheImageAcquisitionandEncode . . . . . . . . . . . . . . . . 46
4.1.5 GPSAcquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.1.6 ImageGeotagging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.1.7 ThreadsManagement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.2 Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4.3 BaseStation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.3.1 MessageFormattingandProtocolImplementation . . . . . . . . . . . . . . . . . . 55
4.3.2 SystemControlandDataMultiplexing . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.3.3 MapModule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
4.3.4 ChartsModule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.3.5 UserInterface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5 ExperimentalResults 63
5.1 MobileStation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.1.1 ImageAcquisitionandEncoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.1.2 GPSAcquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.1.3 EXIF:ImageGeotag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.1.4 SensorsData . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.2 CommunicationLink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.3 BaseStation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.4 FinalTest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
6 Conclusions 73
6.1 FutureWork. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Bibliography 77
x