Control System Development and Technological Investigation for a Climbing Robot in Offshore ...

238 Pages·2012·6.15 MB·English

UNIVERSITY OF OSLO
Department of Informatics
Control System
Development and
Technological
Investigation for a
Climbing Robot in
Offshore platforms
Master Thesis
Akbar Faghihi
Moghaddam
(Shahab)
February 2012
Acknowledgment
Tomy parents& family...
I want to first of all thank my parents and family whose sacrifices allowed
meto behereandfinish thiswork. Ialsowanttospeciallythankmygirlfriend,
Yao Wang, who supported and helped me during the whole process of this
work. InadditionIwouldliketothankmysupervisorsandallthosefriendsand
classmates, whose fruitful discussions inspired me through my work. My dear
classmatesandclosefriendssuchasMagnusLange,MohammadBagher(Puya)
Afsharian, Aryan Esfandiari and Ashkan Mardanpour. At the end I would like
to end this acknowledgment by mentioning my regards to Robotica Osloensis
robotics student community whose membersand resources were alwaysto my
help andinspiration.
Akbar FaghihiMoghaddam(Shahab), February 2011
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Abstract
To improve human safety and environmental concerns, oil and gas industry is
interested in using remote and autonomous robots instead of human workers
on offshore platforms. This will also increase their revenue and allow oper-
ations in places where it is too difficult to operate in. This project is further
development of a custom climbing robot called Walloid at University of Oslo,
currently under development. Walloid is a 4 arm climbing robot with arms
and grippers designed for possible later usage in offshore platforms. Through
this project, as a contribution to the Walloid project, an end effector with grip-
pingfunctionalityandthreeclimbinggaitswithfocusonoptimizationofspeed
were developed. Thereafter, the focus was on developing a control hardware
capable of handling 12 motors and 24 encoders simultaneously. To achieve
this a distributed embedded system consists of five micro-controllers (Arduino
boardswithAtmegaAVR8bit)wasdesignedandimplementedwithtwointer-
connection protocols (ZigBee and RS-232). Based on the hardware design, a
distributed control algorithm wasdesignedtoimplementtheearlierdeveloped
climbing gaits. Thisdistributed navigation program supported remote control-
ling, semi-autonomy, repeating taught (logged) tasks, and power optimization
algorithms to put idle parts into sleep mode. Due to absence of the physical
robot, the evaluation of the work wasdone byself-developed simulation tools.
The power optimization algorithm, together with optimized climbing gaits
reduced the powerconsumption ofthe system significantly.
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Short Contents
Acknowledgment i
Abstract iii
1 Introduction 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Background 5
2.1 Previous Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 ClimbingRobots . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Automation andSmart Agents . . . . . . . . . . . . . . . . . . . . 9
2.4 Offshore Platforms, Challengesand Opportunities . . . . . . . . . 15
2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3 WalloidRobot 27
3.1 Ongoing Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2 WalloidHardware Components . . . . . . . . . . . . . . . . . . . . 28
3.3 CalculatedKinematics andWorkspace . . . . . . . . . . . . . . . . 30
3.4 Reviewand TechUpgrade ofWalloid Robot . . . . . . . . . . . . . 35
3.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4 Top LevelPerspective 41
4.1 Top Down Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2 Analysisofoffshore platforms asan area ofapplication . . . . . . 42
4.3 ClimbingOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.4 Control Hardware, a Distributed EmbeddedSystem (DES) . . . . 43
4.5 Control Algorithm, a Distributed Navigation Program (DNP) . . 43
4.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
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5 DevelopmentProcess 47
5.1 ClimbingStrategy and Design . . . . . . . . . . . . . . . . . . . . . 47
5.2 Control Hardware, the Distributed EmbeddedSystem . . . . . . . 58
5.3 Distributed EmbeddedSystem Design . . . . . . . . . . . . . . . . 66
5.4 Control Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.5 Distributed Navigation Program (DNP) andFeatures . . . . . . . 84
5.6 Simulation andconformability of data . . . . . . . . . . . . . . . . 92
5.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
6 ImplementedControlSystems andResults 99
6.1 Offshore Industry Point Of View . . . . . . . . . . . . . . . . . . . 99
6.2 ClimbingOperation Results . . . . . . . . . . . . . . . . . . . . . . 100
6.3 Control Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
6.4 Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
6.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
7 RobustnessIssues 111
7.1 Listof Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
7.2 Blocked Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
7.3 Positioning afterImproperShutdowns . . . . . . . . . . . . . . . . 113
7.4 Passive Joint Control . . . . . . . . . . . . . . . . . . . . . . . . . . 115
7.5 PowerInterruption . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
7.6 Instability /Current Orientation . . . . . . . . . . . . . . . . . . . 118
7.7 Offline Modus, Network-less Operation . . . . . . . . . . . . . . . 119
7.8 Security Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
7.9 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
8 Conclusion 123
8.1 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
8.2 MyContribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
8.3 Further Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
A Interviews 126
A.1 AndersRøyrøy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
B VisualReports 128
B.1 3DDesigns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
C Remainings 133
C.1 ClimbingOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
C.2 Hardware Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
C.3 Software Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
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D SourceCode 144
D.1 Control program, Java . . . . . . . . . . . . . . . . . . . . . . . . . 144
D.2 Control algorithm, ArduinoC . . . . . . . . . . . . . . . . . . . . . 173
D.3 Simulation, Processing . . . . . . . . . . . . . . . . . . . . . . . . . 192
D.4 Matlab, Workspace . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Listof Figures 217
Bibliography 225
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Contents
Acknowledgment i
Abstract iii
1 Introduction 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Background 5
2.1 Previous Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 ClimbingRobots . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Automation andSmart Agents . . . . . . . . . . . . . . . . . . . . 9
2.3.1 Autonomous Robots . . . . . . . . . . . . . . . . . . . . . . 9
2.3.2 Artificial Intelligence Methods . . . . . . . . . . . . . . . . 11
2.3.3 EmbeddedSystems . . . . . . . . . . . . . . . . . . . . . . . 13
2.4 Offshore Platforms, Challengesand Opportunities . . . . . . . . . 15
2.4.1 Motivations . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.4.2 Automation Opportunities in Offshore Platforms . . . . . 20
2.4.3 Challengesin Automation ofOffshore Platforms . . . . . . 22
2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3 WalloidRobot 27
3.1 Ongoing Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2 WalloidHardware Components . . . . . . . . . . . . . . . . . . . . 28
3.2.1 Encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.3 CalculatedKinematics andWorkspace . . . . . . . . . . . . . . . . 30
3.3.1 One Arm, Three Prismatic Joints . . . . . . . . . . . . . . . 31
3.3.2 Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3.3 Workspace . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.4 Reviewand TechUpgrade ofWalloid Robot . . . . . . . . . . . . . 35
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3.4.1 Adjoining Surface Climbing . . . . . . . . . . . . . . . . . . 36
3.4.2 Speed Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.4.3 Design, Material and Methodsof Production . . . . . . . . 37
3.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4 Top LevelPerspective 41
4.1 Top Down Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2 Analysisofoffshore platforms asan area ofapplication . . . . . . 42
4.3 ClimbingOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.4 Control Hardware, a Distributed EmbeddedSystem (DES) . . . . 43
4.5 Control Algorithm, a Distributed Navigation Program (DNP) . . 43
4.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5 DevelopmentProcess 47
5.1 ClimbingStrategy and Design . . . . . . . . . . . . . . . . . . . . . 47
5.1.1 End Effectors . . . . . . . . . . . . . . . . . . . . . . . . . . 47
5.1.2 ClimbingGaits . . . . . . . . . . . . . . . . . . . . . . . . . 50
5.2 Control Hardware, the Distributed EmbeddedSystem . . . . . . . 58
5.2.1 On-board Motherboard . . . . . . . . . . . . . . . . . . . . 58
5.2.2 Micro-controllers, the embeddedsystem . . . . . . . . . . 60
5.2.3 Centralized vs. Distributed EmbeddedSystems . . . . . . 61
5.2.4 Arduino Boards, the chosen embeddedsystem . . . . . . . 63
5.2.5 Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.3 Distributed EmbeddedSystem Design . . . . . . . . . . . . . . . . 66
5.3.1 Cable BasedDistribution . . . . . . . . . . . . . . . . . . . 66
5.3.2 WirelessDistribution . . . . . . . . . . . . . . . . . . . . . . 70
5.4 Control Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.4.1 Robot-Server-Client(RSC)ArchitectureandDevelopment
Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.4.2 Hardware -Software Interaction . . . . . . . . . . . . . . . 79
5.4.3 Development Process . . . . . . . . . . . . . . . . . . . . . 80
5.5 Distributed Navigation Program (DNP) andFeatures . . . . . . . 84
5.5.1 DNPPositioning Logics . . . . . . . . . . . . . . . . . . . . 84
5.5.2 ReadingSensor Data . . . . . . . . . . . . . . . . . . . . . . 84
5.5.3 Power Optimizer Feature . . . . . . . . . . . . . . . . . . . 85
5.5.4 Remote Control System . . . . . . . . . . . . . . . . . . . . 87
5.5.5 Logging System . . . . . . . . . . . . . . . . . . . . . . . . . 88
5.5.6 Semi-Autonomous System . . . . . . . . . . . . . . . . . . 91
5.6 Simulation andconformability of data . . . . . . . . . . . . . . . . 92
5.6.1 ImplementedSimulations . . . . . . . . . . . . . . . . . . . 92
5.6.2 Conceptual Simulations . . . . . . . . . . . . . . . . . . . . 95
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