DESIGNING AND IMPLEMENTING SINUSOIDAL GAIT CONTROL FOR CHEETAH-CUB QUADRUPED ROBOT
By Linda Wijaya
11110053
A thesis submitted to the Faculty of
ENGINEERING AND INFORMATION TECHNOLOGY
in partial fulfillment of the requirements for the
BACHELOR’S DEGREE in
MECHANICAL ENGINEERING (MECHATRONICS)
SWISS GERMAN UNIVERSITY EduTown BSD City
Tangerang 15339 Indonesia
August 2014
Revision after the Thesis Defense on 21 July 2014
Linda Wijaya STATEMENT BY THE AUTHOR
I hereby declare that this submission is my own work and to the best of my knowledge, it contains no material previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any other degree or diploma at any educational institution, except where due acknowledgement is made in the thesis.
Linda Wijaya
Student Date
Approved by:
Dipl. –Ing. Maralo Sinaga
Thesis Advisor Date
Dr. Ir. Prianggada Indra Tanaya, MME
Thesis Co-Advisor Date
Dr. Ir. Gembong Baskoro, M. Sc.
Dean Date
Linda Wijaya ABSTRACT
DESIGNING AND IMPLEMENTING SINUSOIDAL GAIT CONTROL FOR CHEETAH-CUB QUADRUPED ROBOT
By Linda Wijaya
Dipl. –Ing. Maralo Sinaga, Advisor
Dr. Ir. Prianggada Indra Tanaya, MME, Co-Advisor
SWISS GERMAN UNIVERSITY
This thesis will discuss about the design and development of the sinusoidal gait control for a quadruped robot designed based on the Cheetah-cub quadruped robot, taking special care on the joint angle profile modeling. Developing the actual quadruped robot consisted of building the mechanical, electrical, communication and software systems. The method for implementing the sinusoidal gait control on the newly-developed quadruped robot will also be described. Finally, the implementation method will be tested, and the implementation result will be evaluated and analyzed.
Keywords: quadruped robot, quadrupedal gait, sinusoidal gait, gait control, gait design, gait implementation
Linda Wijaya
© Copyright 2014 by Linda Wijaya All rights reserved
Linda Wijaya DEDICATION
I dedicate this works to Buddha, those who are dearest to me and myself.
Linda Wijaya ACKNOWLEDGEMENTS
My deepest gratitude would be granted to those who supported me with their own ways while I was working on this thesis.
My family members Jong Edy Wijaya, Ngo Piet Yun and Luciana Wijaya, who had handled my needs especially during the hard, chaotic time.
My thesis advisor Dipl.-Ing Maralo Sinaga and co-advisor Dr. Ir. Prianggada Indra Tanaya, MME, along with Dipl.-Ing Ketut Tejawibawa and Cepi Hanafi, MT, who have given supporting and inspiring advices regarding this thesis work—especially during the mechanical parts design—and emotional encouragement whenever I lost confidence on myself.
My senior Nicolaus Levin, who has always been willing to offer his considerate thoughts concerning practical work of my thesis.
Dear colleagues and friends: Aaron Richard Wijaya, Gandhi Winata, Glenn Vialli, Elmore Eleazar, Stevie Lucardi, Jonathan Marshell Kevin, Willy Haliim, Harsyadi Adhiarsa, Kelvin Recia, Victorino Aditya Chandra, Addythia Saphala, Davine Kohar, Saras Safitri, Aryaputra Teguh, Denny Suryamin, Muhammad Fajar Firmansyah, Ryan, Dhuhaa Auga Mulyacita, Daniel Ng, Dirga Pratama, Vassilissa Tjondro, Glenn Sullistio, Bhagya Rio Ellardo and Fredric Ang, because of whom I found enjoyement during our last two weeks before thesis submission despite the physical and mental burden.
My dearest friends Jason Fernandez Tatuil Gosal, Jesse Naftali and Henry Gunawan Hartanto, who have always successfully motivated me—although mostly in undeniably unpleasant and annoying way—and somehow also made me feeling better with each joke shared during our quality time together.
Linda Wijaya TABLE OF CONTENTS
STATEMENT BY THE AUTHOR ... 2
ABSTRACT ... 3
DEDICATION ... 5
ACKNOWLEDGEMENTS ... 6
TABLE OF CONTENTS ... 7
LIST OF FIGURES ... 11
LIST OF TABLES ... 14
CHAPTER 1 - INTRODUCTION ... 16
1.1. Background ... 16
1.2. Research Problems ... 16
1.3. Research Objectives ... 17
1.4. Significance of Study ... 17
1.5. Research Questions ... 18
1.6. Hypothesis ... 18
CHAPTER 2 - LITERATURE REVIEW ... 19
2.1. Similar Works ... 19
2.1.1. SCOUT-1 Quadruped Robot ... 19
2.1.2. SCOUT-2 Quadruped Robot ... 21
2.1.3. Cheetah-cub Quadruped Robot... 24
2.1.4. Comparison Table of the Evaluated Quadruped Robots ... 27
2.2. Theoretical Perspectives ... 28
2.2.1. Quadrupedal Gaits ... 28
Linda Wijaya
2.2.2. Stride Cycle of Cat ... 29
2.2.3. Dynamic Treatment of Legged Locomotion ... 29
2.2.4. Mechanical Torque Calculation ... 30
2.2.5. Smart Servo Motor ... 31
2.2.6. Microcontroller Board ... 33
CHAPTER 3 - METHODOLOGY ... 34
3.1. Methodology Overview ... 34
3.2. Mechanical Modeling ... 35
3.2.1. Kinematic Model ... 35
3.2.2. Dynamic Model ... 38
3.3. Gait Locomotion Design Justification ... 48
3.3.1. Hip Joint Angle Profile ... 51
3.3.2. Knee Joint Angle Profile ... 52
3.4. Platform Design Justification ... 53
3.4.1. Overview of the Whole System ... 53
3.4.2. Mechanical System Design ... 54
3.4.3. Electrical System Design ... 59
3.4.4. Communication System Design ... 63
3.4.5. Software System Design ... 64
3.5. Gait Implementation Method ... 81
3.5.1. Gait Approximation through Position Control ... 82
3.5.2. Gait Approximation through Speed Control ... 82
3.6. Testing Plan ... 84
3.6.1. Motor Test ... 84
3.6.2. Gait Model Performance Test ... 85
Linda Wijaya
3.6.3. Gait Approximation Performance Test ... 85
3.6.4. Gait Implementation Performance Test ... 86
CHAPTER 4 - RESULTS AND DISCUSSIONS ... 88
4.1. Experiment Introduction ... 88
4.2. Result of Motor Test ... 89
4.3. First Gait Parameters Set – Walking Gait ... 92
4.3.1. Result of Gait Model Performance Testing of the 1st Parameters Set .... 93
4.3.2. Result of Gait Approximation Performance Testing of the 1st Parameters Set ... 94
4.4. Second Gait Parameters Set – Trotting Gait ... 97
4.4.1. Result of Gait Model Performance Testing of the 2nd Parameters Set ... 98
4.4.2. Result of Gait Approximation Performance Testing of the 2nd Parameters Set ... 99
4.5. Third Gait Parameters Set – Bounding Gait ... 101
4.5.1. Result of Gait Model Performance Testing of the 3rd Parameters Set .. 102
4.5.2. Result of Gait Approximation Performance Testing of the 3rd Parameters Set ... 103
4.6. Summary of Gait Approximation Performance ... 104
4.7. Result of Gait Implementation Performance Testing ... 105
CHAPTER 5 - CONCLUSION AND FUTURE RECOMMENDATION ... 107
5.1. Conclusion ... 107
5.2. Future Recommendations ... 108
GLOSSARY ... 110
REFERENCES ... 111
Linda Wijaya
APPENDICES ... 112
A. Technical Drawing ... 112
A.1. Front Leg 1 ... 112
A.2. Front Leg 2 or 4 ... 113
A.3. Front Leg 3 ... 114
A.4. Hind Leg 1 ... 115
A.5. Hind Leg 2 or 4 ... 116
A.6. Hind Leg 3 ... 117
A.7. Idler ... 118
A.8. Cam ... 119
A.9. Block ... 120
A.10. Spring Shaft ... 121
A.11. Spring Slot ... 122
A.12. Lower Platform ... 123
A.13. Backbone ... 124
A.14. Upper Platform ... 125
B. ATMega 2560 Datasheet ... 126
C. Source Code ... 130
C.1. GaitSimulator ... 130
C.2. GaitSetpoint ... 154
C.3. Motor Controller ... 170
CURRICULUM VITAE ... 177
Linda Wijaya LIST OF FIGURES
Figure 2.1. SCOUT-1 Quadruped Robot [2] ... 19
Figure 2.2. SCOUT-1 Kinematic Model [2] ... 20
Figure 2.3. SCOUT-2 Quadruped Robot [3] ... 21
Figure 2.4. SCOUT-2 Mechanical System [3] ... 22
Figure 2.5. Cheetah-cub Quadruped Robot [1] ... 24
Figure 2.6. Schematic of SLP-leg (left) and ASLP-leg (right) of Cheetah-cub Quadruped Robot ... 25
Figure 2.7. One Stride Cycle Trajectories of Cheetah-cub Quadruped Robot ... 26
Figure 2.8. Illustration of Horse Walking Gait ... 28
Figure 2.9. Systems of Interconnected Bodies [7] ... 31
Figure 2.10. Dynamixel AX-12A (left) and HerkuleX DRS-0101 (right) ... 32
Figure 2.11. Arduino UNO (left) and Arduino Mega 2560 R3 (right) ... 33
Figure 3.1. Methodology Overview of the Research ... 34
Figure 3.2. Kinematic Model of the Quadruped Leg ... 36
Figure 3.3. Kinematic Model of the Quadruped Body ... 37
Figure 3.4. Free Body Diagram of the Front Right Leg, First Segment ... 38
Figure 3.5. Free Body Diagram of the Front Right Leg, Second Segment ... 39
Figure 3.6. Free Body Diagram of the Front Right Leg, Third Segment ... 40
Figure 3.7. Free Body Diagram of the Front Right Leg, Fourth Segment ... 40
Figure 3.8. Forces Acting on the Quadruped Robot in Static Condition ... 44
Figure 3.9. Free Body Diagram of One Whole Leg as One Rigid Body: Front Leg (right) and Hind Leg (left) ... 47
Figure 3.10. Illustration of Hip and Knee Joint Angle Profile ... 50
Linda Wijaya
Figure 3.11. Overview of the Whole System ... 53
Figure 3.12. Components of the Mechanical System ... 54
Figure 3.13. Leg Illustration of the Quadruped Robot ... 55
Figure 3.14. Leg in Fully-Compressed Condition ... 56
Figure 3.15. Leg in Fully-Extended Condition ... 56
Figure 3.16. Assembled Platform Set ... 57
Figure 3.17. Lower Platform ... 58
Figure 3.18. Upper Platform ... 58
Figure 3.19. Backbone ... 58
Figure 3.20. Components of the Electrical System ... 59
Figure 3.21. Gens ace High Discharge LiPo Battery ... 61
Figure 3.22. Electrical Circuit Diagram of the Quadruped Robot ... 62
Figure 3.23. Components of the Communication System ... 63
Figure 3.24. Components of the Software System ... 64
Figure 3.25. Flowchart of the Motor Controller with Position Approximation ... 67
Figure 3.26. Flowchart of the Motor Controller with Speed Approximation ... 69
Figure 3.27. Flowchart of the Subroutine "pwmCalculation" ... 70
Figure 3.28. Flowchart of GaitSimulator Main Program ... 71
Figure 3.29. Flowchart of the Subroutine "initialization" of GaitSimulator ... 72
Figure 3.30. Flowchart of the Subrouting "updateLeg" ... 73
Figure 3.31. Flowchart of the Subroutine "legDrawing" ... 73
Figure 3.32. Flowchart of the Subroutine "finalization" of GaitSimulator ... 74
Figure 3.33. Flowchart of the Subroutine "resultOutput" ... 74
Figure 3.34. User Interface of GaitSimulator ... 75
Figure 3.35. Example of the Resulting Gait Generated using GaitSimulator ... 77
Linda Wijaya
Figure 3.36. Flowchart of the GaitSetpoint Main Program ... 78
Figure 3.37. User Interface of GaitSetpoint ... 79
Figure 4.1. Angular Velocity as a Function of PWM Duty Cycle Value at Different Input Voltage ... 90
Figure 4.2. Slope m as a Function of Input Voltage – Graphical Representation ... 91
Figure 4.3. Leg Motion Prediction Result, 1st Parameters Set ... 93
Figure 4.4. Leg Motion Prediction Result, 2nd Parameters Set ... 99
Figure 4.5. Leg Motion Prediction Result, 3rd Parameters Set ... 103
Figure 4.6. Implementation of the 1st Set of Gait Parameters ... 106
Linda Wijaya LIST OF TABLES
Table 2.1. Comparison Table of Some Quadruped Robots ... 27
Table 3.1. Phase Offset Differences on Common Quadrupedal Gaits ... 49
Table 3.2. Specification of Dongbu HerkuleX DRS-0101 ... 60
Table 3.3. Specification of Arduino Mega 2560 R3 ... 60
Table 3.4. Specification of Gens ace 2200mAh 7.4V 25C 2S1P LiPo Battery ... 61
Table 3.5. List of Commands Supported by HerkuleX Library for Arduino (1) ... 65
Table 3.6. List of Commands Supported by HerkuleX Library for Arduino (2) ... 66
Table 3.7. List of Additional Commands Added to the Library ... 66
Table 3.8. Leg Parameters of GaitSimulator ... 75
Table 3.9. Angle Profile Parameters of GaitSimulator ... 76
Table 3.10. Simulation Parameters of GaitSimulator ... 77
Table 3.11. Leg Parameters of GaitSetpoint ... 79
Table 3.12. Angle Profile Parameters of GaitSetpoint ... 80
Table 3.13. Gait Parameters of GaitSetpoint ... 81
Table 4.1. Angular Velocity Measurement Result ... 89
Table 4.2. Slope m as a Function of Input Voltage – Tabular Representation ... 91
Table 4.3. First Gait Parameters Set: Walking Gait ... 92
Table 4.4. Hip Motor Setpoints Calculation Result, 1st Parameters Sets ... 95
Table 4.5. Cam Motor Setpoints Calculation Result, 1st Parameters Set ... 97
Table 4.6. Second Gait Parameters Set: Trotting Gait ... 98
Table 4.7. Hip Motor Setpoints Calculation Result, 2nd Parameters Set ... 100
Table 4.8. Cam Motor Setpoints Calculation Result, 2nd Parameters Set ... 101
Table 4.9. Third Gait Parameters Set: Bounding Gait ... 102
Linda Wijaya Table 4.10. Hip Motor Setpoints Calculation Result, 3rd Parameters Set ... 103 Table 4.11. Cam Motor Setpoints Calculation Result, 3rd Parameters Set ... 104 Table 4.12. Comparison of Gait Approximation Result ... 105
