Title Page
ABSTRACT
Contents
Chapter 1. Introduction 15
1.1. Research Motivation 15
1.2. Previous Research Literatures 18
1.2.1. Cyclic Walking with Artificial Single Leg Control 18
1.2.2. Biped Robot System with ZMP Control 20
1.2.3. Control of Multi-legged Robot with Gait Pattern Analysis 23
1.2.4. Quadruped Robot System inspired by Mammalian 25
1.3. Research Objectives and Thesis Structure 31
Chapter 2. Role of the Spinal Motion of the Feline Animal for the Speed Increase 33
2.1. Introduction: Importance of the Spinal Motion 33
2.2. Selection of the Spinal Joint Configuration 36
2.2.1. Bone Structure of the Spinal Column of the Cat 36
2.2.2. Passive Bending Range of the Cat 36
2.3. Dynamic Observation of Feline Spinal Motion 43
2.3.1. Motivation of Dynamic Observation of Feline Spinal Motion 43
2.3.2. Marker Placement based on an experimental object for the dynamic behavioral experiment 43
2.3.3. Experimental Environment 44
2.3.4. Data Measurement 44
2.4. Role of Spinal Motion for Speed Increase 50
2.4.1. Role of Spinal Motion I : Pelvic-Spinal Motion Synchronization 50
2.4.2. Role of Spinal Motion II : Body CoM Pivot to Optimal Extension Flight 59
Chapter 3. Sprinter: Bio-inspired Quadruped Experimental Set for Spinal Motion 67
3.1. Introduction 67
3.2. Bio-Inspired Quadruped System: Sprinter 67
3.2.1. Bio-inspired Under-actuation Leg Design 67
3.2.2. Design of Experimental System Structure based on Cat Skeletal model 73
3.2.3. Design of Data Measurement Unit 73
3.3. Quadruped Motion Controller Design 80
3.3.1. Gait Pattern Modulator Design and Control Architecture for the Hindlimb Bounding Motion 80
3.3.2. Gait Pattern Modulator Design and Control Architecture for Quadruped Bounding Motion 84
Chapter 4. Optimal Spinal Motion Profile Based on Q-Learning Algorithm 86
4.1. Importance of the Optimal Spinal Profile with Learning Algorithm 86
4.1.1. Simplification of 2D-planar quadruped robot system design 86
4.1.2. Introduction to the Reinforcement Learning 86
4.1.3. Objective: Re-Design of the Spinal Motion Profile for unit step bounding gait 87
4.2. Optimal Spinal Motion Profile Design with Kinematic Model 90
4.2.1. Introduction to Q-Learning Algorithm 90
4.2.2. The Optimal Spinal Motion Profile Re-Design with Q-learning Algorithm 90
4.3. Optimal Spinal Motion Profile into Dynamic System 104
4.3.1. Optimal Spinal Motion Profile into Dynamic Simulator 104
4.3.2. Optimal Spinal Motion Profile into 2D-Planar Quadruped System 111
Chapter 5. Conclusion and Future Work 118
5.1. Conclusion 118
5.2. Future Work 119
REFERENCE 121
Summary 126
이력서(Curriculum Vitae) 129
Table 2.1. Initial Marker Positions on the Experimental Object 46
Table 2.2. Length Variation of the 9 Body Links at 2 different States 46
Table 2.3. Relative Angle and Speed Variation during Low Speed Galloping 54
Table 2.4. Relative Angle and Speed Variation during High Speed Galloping 54
Table 4.1. Pseudo Code of Q-learning algorithm 95
Table 4.2. Parameter of the Hindlimb/Forelimb Stance Model 96
Table 4.3. Parameter of the Dynamic Simulator: Simulation, Mass, and Length Data 107
Table 4.4. Parameter of the Dynamic Simulator: Initial Input Data 107
Figure 1.1. Optimal Strategy of Quadruped Animal for Terrains 17
Figure 1.2. Galloping Sequence of Cheetah 17
Figure 1.3. One Leg Hopping Machine and its Simplified Model 19
Figure 1.4. Vertical Movement Cycle of the Hopping Leg 19
Figure 1.5. Definition of the Zero Moment Point 21
Figure 1.6. Cart-table model for Zero Moment Point 21
Figure 1.7. Walking Pattern Genernation based on ZMP 22
Figure 1.8. Follow Chart of Walking Pattern Genernation Algorithm based on ZMP 22
Figure 1.9. Support Polygon of a Multi-Legged Robot System 24
Figure 1.10. Gait Position and its Parameters 24
Figure 1.11. Wave Gait of a Quadruped Robot 24
Figure 1.12. Quadruped Running Machine 27
Figure 1.13. Dynamic Gait Patterns, Trot, Pace, Bounding 27
Figure 1.14. Tekken 2 and Control Design with Central Pattern Generator 28
Figure 1.15. Scout II and its compliant prismatic leg component 28
Figure 1.16. Specification of BigDog and its Operation in 35˚ slope 29
Figure 1.17. LS3 Squad Unit for the US Army 29
Figure 1.18. Cheetah Robot Galloping in Treadmill Environment 29
Figure 1.19. MIT Cheetah Galloping in Outdoor Environment 30
Figure 1.20. Cheetah Cub Trotting in Outdoor Environment 30
Figure 1.21. Boston Dynmics Wildcat Galloping in Outdoor Environment 30
Figure 2.1. Energy Fluctuations in a Galloping Gait Pattern 35
Figure 2.2. Half Bound of Quadruped Animal, Pika 35
Figure 2.3. Vertebral Column of a Felis Catus Domestica 39
Figure 2.4. Experimental Set of the Sagittal Angle Range of the Lumbar Vertebrae 40
Figure 2.5. Experimental Components of the Sagittal Angle Range of the Lumbar Vertebrae 40
Figure 2.6. Sagittal Angle Range of the Lumbar Vertebrae in Flexion 41
Figure 2.7. Result of the Sagittal Angle Range of the Lumbar Vertebrae in Extension 41
Figure 2.8. Flexion and Extension of the Body Trunk of a Domestic Cat 42
Figure 2.9. Relationship between Thoracolumbar and Lumbosacral Vertebrae 42
Figure 2.10. Marker Placements on the Legs 47
Figure 2.11. Marker Placements on the Spinal Column 47
Figure 2.12 (A) Experimental Set with a High Speed Camera and Infrared Motion Capture. Cameras... 48
Figure 2.13. Center of Mass Location Region in X Axis on the Body Trunk 48
Figure 2.14. (A) Speed variation of the proximal points on the link 5(S1-S2), (B) Speed variation of the... 49
Figure 2.15. Measurement Angle Data: Relative Spinal and Pelvic Angle 49
Figure 2.16. Relative Angles at Low Speed Galloping Gait 53
Figure 2.17. Relative Angles at High Speed Galloping Gait 53
Figure 2.18. Relative Angle Tendency from 10 Experiments at Low Speed Galloping Gait 55
Figure 2.19. Averaged Relative Angle Tendency at Low Speed Galloping Gait 55
Figure 2.20. Forward Speed Tendency from 10 Experiments at Low Speed Galloping Gait 55
Figure 2.21. Averaged Forward Speed Tendency at Low Speed Galloping Gait 56
Figure 2.22. Relative Angle Tendency from 10 Experiments at High Speed Galloping Gait 56
Figure 2.23. Averaged Relative Angle Tendency at High Speed Galloping Gait 56
Figure 2.24. Forward Speed Tendency from 10 Experiments at High Speed Galloping Gait 57
Figure 2.25. Averaged Forward Speed Tendency at High Speed Galloping Gait 57
Figure 2.26. Averaged Relative Angular Velocity Tendency at Low Speed Galloping 57
Figure 2.27. Averaged Relative Angular Velocity Tendency at High Speed Galloping 58
Figure 2.28. Motion Match Diagram based on the Exerted Torques at the Hindlimb Stance 58
Figure 2.29. Averaged Relative Angular Velocity Tendency at High Speed Galloping 61
Figure 2.30. 3D plot of the relationship among CoM Length, CoM Speed, and Spinal Angle Variation at... 61
Figure 2.31. Plot of the relationship between CoM Speed and Spinal Angle 61
Figure 2.32. Plot of the relationship between CoM Speed and Length 62
Figure 2.33. Plot of the relationship between CoM Length and Spinal Angle 62
Figure 2.34. Simplification Map of the Hindlimb Stance Phase as the Spring-Mass System 62
Figure 2.35. 3D plot of the relationship among CoM Angle, CoM Speed, and Spinal Angular Rate at the... 64
Figure 2.36. Plot of the relationship between CoM Speed and Angle 64
Figure 2.37. Plot of the relationship between CoM Speed and Spinal Angular Rate 64
Figure 2.38. Plot of the relationship between CoM Speed and Hindlimb Angular Rate 65
Figure 2.39. Plot of the relationship between CoM Angle and Spinal Angular Rate 65
Figure 2.40. Plot of the relationship between CoM Speed and Spinal Angular Rate 65
Figure 2.41. Plot of the relationship between CoM Speed and Hindlimb Angular Rate 66
Figure 2.42. Phase Map of the Hindlimb Stance Phase as the Spring-Mass System 66
Figure 3.1. Dissected Hindlimb of a Domestic Cat 70
Figure 3.2. Rotational Range of the Hip Joint of the Hindlimb 70
Figure 3.3. Rotational Range of the Knee Joint of the Hindlimb 70
Figure 3.4. Leg Modification by Dual 4 bar Passive Linkage Combination 71
Figure 3.5. Rotational Range of Dual Four bar Passive Linkage Combination 71
Figure 3.6. Parallel Angle Variation between Hip and Knee Angle 71
Figure 3.7. Parallel Angle Variation between Hip and Knee Angle 72
Figure 3.8. Unit Cycle of the Leg Motion in Sagittal Plane 72
Figure 3.9. Morphologically Inspired Quadruped System: Length, Angle 76
Figure 3.10. Tethered Boom attached to the Sprinter System 76
Figure 3.11. Planar Boom with a Linear Guide 77
Figure 3.12. Motion Capture Camera Set for Quadruped Planar Motion 77
Figure 3.13. Mechanical Framework of the Sprinter Platform 78
Figure 3.14. Electronic Framework of the Sprinter Platform 78
Figure 3.15. Electronic Control Unit(ECU) of the Sprinter System 79
Figure 3.16. Control Flow of the Sprinter System 79
Figure 3.17. Experimental Set of the Hindlimb Stance Phase 82
Figure 3.18. Block Diagram of the Hindlimb Stance Phase Locomotion Control 82
Figure 3.19. Dynamic Tendency of the Non-Spinal Hindlimb Stance 83
Figure 3.20. Dynamic Tendency of the Pelvic-Spinal Synchronized Hindlimb Stance 83
Figure 3.21. GRF in X, Y axis 83
Figure 3.22. Concept of the Gait Pattern Modulator in the Sprinter Controller 85
Figure 3.23. Phase Graph for Relative Sequence of the Spinal Bounding Gait 85
Figure 3.24. Gait Pattern Modulator Signals for Spinal Bounding Gait 85
Figure 4.1. Needs for the Optimized Spinal Profile: Simplified Leg Design 88
Figure 4.2. Needs for the Optimized Spinal Profile: Different Linkage Configuration 88
Figure 4.3. Definition of Reinforcement Learning 89
Figure 4.4. Concept of the Optimal Spinal Motion Profile Design 89
Figure 4.5. Overall Process of the Optimal Spinal Motion Profile Design with Q-Learning 95
Figure 4.6. Hindlimb Stance Model based on Kinematic Chain 96
Figure 4.7. Forelimb Stance Model based on Kinematic Chain 96
Figure 4.8. Velocity based Sigmoid Reward Function 97
Figure 4.9. Flowchart of Q-learning Algorithm for the Optimal Spinal Motion Profile 97
Figure 4.10. Initial Condition of Hindlimb Stance Phase 98
Figure 4.11. Spine Trajectory of the Hindlimb Stance Phase in Non-Spinal/Spinal Motion 98
Figure 4.12. Spinal Angle of the Hindlimb Stance Phase in Non-Spinal/Spinal Motion 99
Figure 4.13. CoM Speed of the Hindlimb Stance Phase in Non-Spinal/Spinal Motion 99
Figure 4.14. CoM Length during the Hindlimb Stance Phase 99
Figure 4.15. Plot of CoM Speed with respect to Angular Velocity 100
Figure 4.16. Initial Condition of Forelimb Stance Phase 100
Figure 4.17. Spine Trajectory of the Hindlimb Stance Phase in Non-Spinal/Spinal Motion 101
Figure 4.18. Spinal Angle of the Hindlimb Stance Phase in Non-Spinal/Spinal Motion 101
Figure 4.19. CoM Speed of the Hindlimb Stance Phase in Non-Spinal/Spinal Motion 101
Figure 4.20. CoM Length during the Hindlimb Stance Phase 102
Figure 4.21. Plot of CoM Speed with respect to Angular Velocity 102
Figure 4.22. Spinal Motion Profile for the Unit Bounding Gait 102
Figure 4.23. Fitted Spinal Motion Profile for the Unit Bounding Gait 103
Figure 4.24. Fitted Spinal Angular Velocity Profile for the Unit Bounding Gait 103
Figure 4.25. Dynamic Simulation Environment 106
Figure 4.26. Overall Trajectory of the Non-Spinal Bounding 108
Figure 4.27. Dynamic Simulation Result for the Non-Spinal Bounding 108
Figure 4.28. Overall Trajectory of the Spinal Bounding 109
Figure 4.29. Dynamic Simulation Result for the Spinal Bounding 109
Figure 4.30. CoM Speed with respect to the CoM length at the Hindlimb Stance Phase 110
Figure 4.31. CoM Speed with respect to the Time at the Hindlimb Stance Phase 110
Figure 4.32. CoM Speed with respect to the Spinal Angular Velocity at the Hindlimb Stance Phase 110
Figure 4.33. Experimental Setup for the Unit Step Bounding 113
Figure 4.34. Non Spinal Bounding for Unit Step 113
Figure 4.35. CoM Speed for the Non Spinal Bounding for Unit Step 114
Figure 4.36. Spinal Angle for the Non Spinal Bounding for Unit Step 114
Figure 4.37. Spinal Bounding for Unit Step 115
Figure 4.38. CoM Speed for the Spinal Bounding for Unit Step 115
Figure 4.39. Spinal Angle for the Spinal Bounding for Unit Step 116
Figure 4.40. CoM Speed with respect to CoM Length for Unit Step Bounding 116
Figure 4.41. CoM Speed with respect to Time for Unit Step Bounding 117
Figure 4.42. Spinal Angular Velocity with respect to CoM Speed for Unit Step Bounding 117
Figure 5.1. Sprinter System with Wireless Camera on Treadmill Environment 120
Figure 5.2. Wireless Camera Data during the Bounding Gait 120
Figure 5.3. Consistency of the Cervical Vertebral Column during Galloping Gait 120