Simulation, Control and Path Planning for Articulated Unmanned Ground Vehicles

145 Pages·2016·6.42 MB·English

Simulation, Control and Path Planning for
Articulated Unmanned Ground Vehicles
Yutong Yan
YutongYan
VT2015
MasterThesis,30ECTS
Master’sPrograminRoboticsandControl,120ECTS

Simulation, Control and Path Planning for
Articulated Unmanned Ground Vehicle
by
Yutong Yan
SubmittedtotheDepartmentofAppliedPhysicsandElectronicsinpartial
fulfillmentoftherequirementsforthedegreeofMasterofScienceinElectronics
(SpecializationinRoboticsandControl)
at
Umea˚ University
2016
Writtenby
Yutong Yan
Master Student
Certifiedby
Kalle Prorok
Thesis Supervisor
Certifiedby
Anders Backman
Thesis Supervisor
Acceptedby
Sven Ro¨nnba¨ck
Examiner, Program Coordinator
iii

Abstract
The purpose of this project is to implement obstacle avoidance algo-
rithms to drive the articulated vehicle autonomously in an unknown
environment, which is simulated by AgX Dynamics™ simulation soft-
ware and controlled by Matlab® programming software. Three driving
modesaredevelopedfordrivingthevehicle(Manual,Semi-autonomous
andAutonomous)inthisproject. Pathtrackingalgorithmsandobstacle
avoidance algorithms are implemented to navigate the vehicle. A GUI
was built and used for the manual driving mode in this project. The
semi-autonomous mode checked different cases: change lanes, U-turn,
followingaline,followingapathandfigure8course. Theautonomous
modeisimplementedtodrivethearticulatedvehicleinanunknownen-
vironment with moving to a pose path tracking algorithm and VFH+
obstacle avoidance algorithm. Thus, the simulation model and VFH+
obstacle avoidance algorithm seems to be working fine and still can be
improvedfortheautonomousvehicle. Theresultofthisprojectshowed
agoodperformanceofthesimulationmodel. Moreover,thissimulation
software helps to minimize the cost of the articulated vehicle since all
testsareinthesimulationratherthaninthereality.
Keywords: AgXDynamics™,Matlab®,Autonomous,Articu-
latedvehicle,Pathtracking,ObstacleAvoidance,VFH+,GUI
i

Acknowledgments
My deepest gratitude is to my supervisor, Kalle Prorok, for his patience, motivation, and
immenseknowledge. Hissupporthelpedmeinallthetimeofresearchandforreadingmy
Masterthesisreports,commentingonmyviewsandhelpingmeunderstandandenrichmy
ideas.
My sincere gratitude is to my co-advisor, Anders Backman, who has always been there to
helpmesortoutthetechnicaldetailsofthesimulationsoftware.
I am grateful to my examiner, Sven Ro¨nnba¨ck for his encouragement and practical advice
throughmyentireMasterperiod. Inaddition,providingalltheresourcesIneeded.
My gratitude to Algoryx Simulation AB Company and all its amazing staff, for giving me
theopportunitytodomyMasterthesiswithAgXDynamicssimulationsoftware.
Andthankyou,allmyfriends,foralwaysstandingbymyside.
Lastbutnottheleast,IwouldliketothankmyparentsYuanshengYanandAipingTian,for
theirendlesssupportandtrust. Iamsoblessedtohavesuchawonderfulfamily.
Umea˚,September16,2016
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Contents
Abstract i
Acknowledgments iii
ListofFigures xii
ListofTables xiii
ListofAlgorithms xv
ListofAcronyms xvii
ListofSymbols xix
1 Introduction 1
1.1 Background 1
1.2 Goal 2
1.3 Simulators 2
1.4 Deliverable 2
1.5 Scenario 3
1.6 RiskAnalysis 3
1.6.1 Strengths 3
1.6.2 Weaknesses 3
1.6.3 Opportunities 3
1.6.4 Threats 3
1.7 Resources 4
1.8 Requirements 5
1.9 LiteratureReview 5
1.10 ThesisOutline 6
2 Methods 7
v
2.1 Clarification 7
2.2 VehicleModel 7
2.3 DegreesOfFreedom 8
2.4 AngleDefinition 10
2.5 TurningRadiusandSlipEffect 11
2.6 HomogeneousTransformationinTwoDimensions 12
2.7 VehicleBasicControl 14
2.7.1 Engine 14
2.7.2 Clutch 14
2.7.3 Gear 15
2.7.4 Throttle 15
2.7.5 Steering 15
2.8 Sensors 15
2.8.1 LaserRangeFinder 15
2.8.2 InertialNavigationSystem 16
2.9 PIDController 18
2.10 HistogrammicInMotionMapping 19
2.11 PathTrackingAlgorithms 20
2.11.1 MovingtoaPoint 21
2.11.2 MovingtoaPose 21
2.11.3 Look-aheadDistance 22
2.12 Semi-AutonomousAlgorithms 23
2.12.1 ChangeLanes 23
2.12.2 U-turn 23
2.12.3 FollowingaLine 25
2.12.4 FollowingaPath 26
2.12.5 Figure8 27
2.13 ObstacleAvoidanceAlgorithms 28
2.13.1 VectorFieldHistogram 29
2.13.2 VectorFieldHistogram+ 32
3 Results 41
3.1 VehicleModelandFrameProblem 41
3.2 ManualDriving 46
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