Table of Contents

1 Introduction ........................................... 1
1.1 Introduction ........................................ 1
1.2 Hydrodynamic Modeling and Testing ..................... 3
1.2.1 Hydrodynamic Modeling ......................... 4
1.2.2 Hydrodynamic Experimental Techniques.............. 5
1.3 Kinematic Modeling and Control ......................... 8
1.3.1 Kinematic Measurement of Fish Swimming ........... 8
1.3.2 Motion Control ................................ 9
1.4 Learning Control and Motion Optimization ................. 11
1.4.1 Learning Fishlike Swimming ...................... 11
1.4.2 Motion Optimization ............................ 13
1.5 Coordination ....................................... 14
1.5.1 AFSA ....................................... 15
1.5.2 Coordinated Control of Multiple Robotic Fish .......... 16
1.6 Concluding Remarks.................................. 18
References ............................................. 19
2 Bioinspired Fish Body Wave Model Considering Linear Density ... 25
2.1 Introduction ........................................ 25
2.2 Problem Formulation ................................. 27
2.2.1 An Overview of Fish Body Wave ................... 27
2.2.2 Necessary Conditions of Steady Swimming ............ 28
2.3 Design of Body Wave Considering Linear Density ............ 29
2.4 Design of Fish Morphology: Two Cases Studies ............. 32
2.4.1 Design of Main Body ........................... 32
2.4.2 Formation of Caudal Fin and Its Counterpart........... 35
2.4.3 Formation of Pectoral Fin and Its Counterpart .......... 36
2.4.4 Formation of Pelvic Fin and Its Counterpart ........... 36
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2.5 Simulation and Result Analysis .......................... 37
2.6 Discussion ......................................... 42
2.7 Concluding Remarks.................................. 43
References ............................................. 43
3 Implementing Flexible and Fast Turning Maneuvers
of Multijoint Robotic Fish ................................. 47
3.1 Introduction ........................................ 47
3.2 Analysis and Control of C-Start.......................... 49
3.2.1 Design of Stage 1 .............................. 50
3.2.2 Design of Stage 2 .............................. 53
3.2.3 Design of Stage 3 .............................. 55
3.2.4 Closed-Loop Control of the Turning Angle ............ 56
3.3 Experiments and Results ............................... 58
3.3.1 Experimental Setup ............................. 58
3.3.2 Experiments on the Blunt Fish ..................... 60
3.3.3 Experiments on the Slim Fish ...................... 63
3.4 Discussion ......................................... 66
3.5 Concluding Remarks.................................. 67
References ............................................. 68
4 CPG-Based Swimming Control ............................. 71
4.1 Introduction ........................................ 71
4.2 Overview of Robotic Fish Prototype ...................... 73
4.2.1 Mechatronic Design ............................. 73
4.2.2 Swimming Gaits Design.......................... 75
4.2.3 Hardware and Software Design of the Controller ........ 75
4.3 Design of a Two-Phase Control System .................... 77
4.3.1 A Two-Phase CPG Control Architecture .............. 77
4.3.2 CPG Model ................................... 78
4.3.3 Lower Reflex Model ............................ 79
4.3.4 Medium Sensory Feedback Model .................. 81
4.3.5 High Hierarchical Feedback Control Model ............ 83
4.4 FSM-Based Gait Transition ............................. 85
4.5 Swimming Performance Optimization ..................... 87
4.5.1 Swimming Performance Indicators .................. 87
4.5.2 Performance Under Consistent Phase Differences........ 88
4.5.3 Performance Under Inconsistent Phase Differences ...... 90
4.6 Test Results Analysis ................................. 91
4.7 Discussion ......................................... 94
4.8 Conclusion and Remark ............................... 97
References ............................................. 98
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5 3D Maneuvering Control of a Robotic Fish ................... 101
5.1 Introduction ........................................ 101
5.2 Mechatronic Design of the Updated Robotic Fish ............. 102
5.2.1 Head Design .................................. 103
5.2.2 Pectoral Fins .................................. 104
5.2.3 Multilink Propulsive Mechanism ................... 105
5.3 Analysis and Control of 3D Maneuvers .................... 106
5.3.1 CPG Network ................................. 106
5.3.2 Rotational Maneuvers ........................... 108
5.3.3 Translational Maneuvers ......................... 112
5.3.4 Head Motion Control ............................ 113
5.4 Experiments and Discussion ............................ 114
5.4.1 Testing of Rotational Maneuvers ................... 114
5.4.2 Testing of Backward Swimming .................... 116
5.5 Discussion ......................................... 117
5.6 Concluding Remarks.................................. 119
References ............................................. 120
6 Control of Yaw and Pitch Maneuvers of a Multilink Dolphin
Robot ................................................ 123
6.1 Introduction ........................................ 123
6.2 Overview of the Dolphin Robot ......................... 125
6.3 Analysis and Control of Yaw Turn ....................... 127
6.3.1 Analysis of Yaw Turn ........................... 127
6.3.2 A Two-Segment Model for Yaw Turns ............... 127
6.4 Analysis and Control of Pitch Turn ....................... 128
6.4.1 Analysis of Pitch Turn ........................... 128
6.4.2 Design of the Unbending Phase .................... 129
6.4.3 Maintaining the Pitch Angle ....................... 132
6.5 Results and Discussions ............................... 134
6.5.1 Experimental Setup ............................. 134
6.5.2 Testing of Yaw Turns ........................... 135
6.5.3 Testing of Wide-Range Pitch Turns ................. 136
6.6 Discussion ......................................... 145
6.7 Concluding Remarks.................................. 147
References ............................................. 147
7 Leaping Control of Self-propelled Robotic Dolphin ............. 149
7.1 Introduction ........................................ 149
7.2 Theoretical Analysis of Dolphin Leaping Motion ............. 151
7.3 Motion Control of Leaping Robotic Dolphin ................ 154
7.3.1 Prototype of Leaping Robotic Dolphin ............... 155
7.3.2 AoA-Based Speed Control ........................ 158
7.3.3 Pitch Control .................................. 162
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7.3.4 Roll Control .................................. 164
7.3.5 Yaw Control .................................. 164
7.3.6 Depth Control ................................. 165
7.4 Experiments and Results ............................... 165
7.4.1 Speed Tests ................................... 165
7.4.2 Leap Tests ................................... 167
7.5 Discussion ......................................... 169
7.6 Concluding Remarks.................................. 170
References ............................................. 171
8 Motion Control of Self-propelled Robotic Jellyfish .............. 173
8.1 Introduction ........................................ 173
8.2 Prototype of the Self-propelled Robotic Jellyfish ............. 174
8.2.1 Mechanical Design ............................. 174
8.2.2 Analysis for Barycenter Adjustment Mechanism
of the Robotic Jellyfish .......................... 178
8.2.3 Dynamic Analysis .............................. 181
8.3 Reinforcement Learning Based Attitude Control .............. 184
8.3.1 A Brief Introduction of Reinforcement Learning ........ 185
8.3.2 Attitude Control of the Robotic Jellyfish .............. 186
8.4 Experiments and Results ............................... 191
8.5 Discussion ......................................... 194
8.6 Concluding Remarks.................................. 195
References ............................................. 196
9 Summary and Outlook ................................... 197
9.1 Technical Contributions ............................... 197
9.2 Future Studies ...................................... 200
Index ...................................................... 203