PRECISION MECHATRONICS LAB ROBOT DEVELOPMENT A Thesis by ADAM G. ROGERS

219 Pages·2007·5.16 MB·English

PRECISION MECHATRONICS LAB ROBOT DEVELOPMENT

A Thesis
by
ADAM G. ROGERS

Submitted to the Office of Graduate Studies of
Texas A&M University
in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE

December 2007

Major Subject: Mechanical Engineering
PRECISION MECHATRONICS LAB ROBOT DEVELOPMENT

A Thesis
by
ADAM G. ROGERS

Submitted to the Office of Graduate Studies of
Texas A&M University
in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE

Approved by:

Chair of Committee, Won-jong Kim
Committee Members, Yoonsuck Choe
Daejong Kim
Head of Department, Dennis O' Neal

December 2007

Major Subject: Mechanical Engineering
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ABSTRACT

Precision Mechatronics Lab Robot Development. (December 2007)

Adam G. Rogers, B.S., Southwest Texas University

Chair of Advisory Committee: Dr. Won-jong Kim

This thesis presents the results from a modification of a previously existing research
project titled the Intelligent Pothole Repair Vehicle (IPRV). The direction of the
research in this thesis was changed toward the development of an industrially based
mobile robot. The principal goal of this work was the demonstration of the Precision
Mechatronics Lab (PML) robot. This robot should be capable of traversing any known
distance while maintaining a minimal position error. An optical correction capability
has been added with the addition of a webcam and the appropriate image processing
software. The primary development goal was the ability to maintain the accuracy and
performance of the robot with inexpensive and low-resolution hardware. Combining the
two abilities of dead-reckoning and optical correction on a single platform will yield a
robot with the ability to accurately travel any distance. As shown in this thesis, the
additional capability of off-loading its visual processing tasks to a remote computer
allows the PML robot to be developed with less expensive hardware. The majority of
the literature research presented in this paper is in the area of visual processing. Various
methods used in industry to accomplish robotic mobility, optical processing, image
enhancement, and target interception have been presented. This background material is
important in understanding the complexity of this field of research and the potential
application of the work conducted in this thesis. The methods shown in this research can
be extended to other small robotic vehicles, with two separate drive wheels. An
empirical method based upon system identification was used to develop the motion
controllers. This research demonstrates a successful combination of a dead-reckoning
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capability, an optical correction method, and a simplified controller methodology
capable of accurate path following. Implementation of this procedure could be extended
to multiple and inexpensive robots used in a manufacturing setting.
v

To my wife, ….and cat
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ACKNOWLEDGMENTS

I would like to take this opportunity to thank my fellow students at A & M. They
helped shed light and bring perspective during my time here. I would especially like to
mention Reza S., Sheridon H., Ruzbeh H. and Ali S. for their help, friendship and
academic support. Thanks to G-Wayne and Suze for all the gourmet meals during my
stay in College Station. All the time I spent at the THRC helped me focus and study
those long hours. Thanks to Randall L. for the discounts. Mostly I would like to thank
my Amy for her unflagging support and constant cheer.
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TABLE OF CONTENTS

Page

ABSTRACT.............................................................................................................. iii

DEDICATION.......................................................................................................... v

ACKNOWLEDGMENTS......................................................................................... vi

TABLE OF CONTENTS.......................................................................................... vii

LIST OF FIGURES................................................................................................... xi

LIST OF TABLES.................................................................................................... xiv

CHAPTER

I INTRODUCTION................................................................................ 1

1.1 History......................................................................................... 2
1.2 Thesis Objectives........................................................................ 3
1.2.1 First thesis objective........................................................... 3
1.2.2 Second thesis objective...................................................... 4
1.2.3 Third thesis objective......................................................... 5

II LITERATURE REVIEW..................................................................... 7

2.1 Possible Developmental Topics.................................................. 7
2.1.1 Household robots................................................................ 8
2.1.2 Factory robots..................................................................... 9
2.2 Developmental Challenges.......................................................... 9
2.2.1 Hardware based front-end image pre-processor................. 10
2.2.2 Distributed-architecture control systems............................ 10
2.2.3 Multiple-sensor control system.......................................... 11
2.2.4 The development of an inexpensive secondary
sensor system...................................................................... 12
2.2.5 Mapping and localization................................................... 13
2.2.6 Communication between a human and a robot.................. 14
2.3 Summary of Literature Review................................................... 15
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CHAPTER ............................................................................................ Page

III PML DESIGN OVERVIEW............................................................. 16

3.1 Introduction................................................................................. 16
3.1.1 Examples of redesign......................................................... 16
3.2 System Overview........................................................................ 17
3.2.1 Dead reckoning overview................................................... 18
3.2.2 Optical-correction overview............................................... 19
3.2.3 Course-correction overview............................................... 24
3.3 Hardware Overview.................................................................... 26
3.3.1 Wheelchair and power supply............................................ 27
3.3.2 System hardware overview................................................ 29
3.4 Robot Operating System Overview............................................. 32

IV MOTOR CONTROL SYSTEM........................................................... 36

4.1 Introduction................................................................................. 36
4.2 IFB Voltage Controller................................................................ 37
4.2.1 Voltage controller output range.......................................... 39
4.2.2 Voltage controller system design....................................... 40
4.2.3 Voltage controller circuit design........................................ 42
4.2.4 Voltage controller summary............................................... 44
4.3 Joystick and JSIC Circuit............................................................ 45
4.4 MC-7 and Gear Motor................................................................. 47
4.4.1 MC-7 motor controller....................................................... 48
4.4.2 Gear motor description....................................................... 50
4.5 Summary of Motor Control System............................................ 50

V POSITION SENSING AND 5-VDC POWER SUPPLY.................... 53

5.1 Introduction................................................................................. 53
5.2 Five-VDC Power Supply............................................................ 53
5.3 Four-Bit Position Counter Buffer System................................... 55
5.3.1 Minimum sampling frequency for position count.............. 57
5.3.2 Position sensor diagram..................................................... 58
5.3.3 Application of position buffer............................................ 59
5.3.4 Selection of magnets.......................................................... 59
5.3.5 Use of the NAND IC in the position sensor circuit............ 60
5.4 Summary of Electronics System................................................. 64
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CHAPTER ............................................................................................ Page

VI OPTICAL CORRECTION SYSTEM.................................................. 63

6.1 Introduction................................................................................. 63
6.1.1 Camera hardware................................................................ 64
6.1.2 Organization of this chapter............................................... 66
6.2 Server-Side Optical Correction Program.................................... 67
6.2.1 Server-side webcam driver................................................. 67
6.2.2 Server-side optical correction data return.......................... 68
6.3 Client-Side OCS Manager........................................................... 69
6.3.1 Client-side data extraction.................................................. 69
6.3.2 Client-side data conversion module................................... 71
6.3.3 Development of the data-conversion mapping algorithm.. 73
6.3.4 Correlation of image data to real position.......................... 75
6.3.5 Decoupling of input variables............................................ 79
6.3.6 Development of the one-to-one map equation................... 81
6.3.7 Development of one-to-one map with a non-zero (cid:1)........... 85
6.3.8 Error data encoding............................................................ 87
6.3.9 Use of error data by robot to correct for positional error... 89
6.4 Summary of Optical System....................................................... 89

VII ROBOT OPERATING SYSTEM........................................................ 91

7.1 Introduction.................................................................................... 91
7.2 Peripheral Modules ........................................................................ 92
7.2.1 DIO device......................................................................... 92
7.2.2 ROS wireless capability..................................................... 95
7.2.3 Operational data................................................................. 99
7.2.4 Path database...................................................................... 99
7.3 Program Design.............................................................................. 101
7.3.1 Main program..................................................................... 102
7.3.2 Subroutines used by the main program.............................. 103
7.3.3 Modules.............................................................................. 104
7.4 Straight Path Controller.................................................................. 105
7.4.1 Definition of units used in ROS and controllers................ 106
7.4.2 SP-controller-error signal computation.............................. 107
7.4.3 One-to-one map between OffsetRef and RefAng.............. 109
7.4.4 Supplemental small-angle oscillation controller................ 110
7.4.5 SP-controller experimental results and conclusions........... 112
7.5 LA-Control..................................................................................... 115
7.5.1 Design of LA-controller..................................................... 116
7.5.2 LA-control conclusion........................................................ 120
7.6 Summary of ROS........................................................................... 125
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CHAPTER ............................................................................................Page

VIII CONCLUSIONS AND SUMMARY................................................... 126

8.1 Specific Accomplishments............................................................. 127
8.2 Limitations and Future Work......................................................... 128
8.3 Conclusions.................................................................................... 128

REFERENCES.......................................................................................................... 130

APPENDIX A........................................................................................................... 133

APPENDIX B........................................................................................................... 171

APPENDIX C........................................................................................................... 181

VITA......................................................................................................................... 205