Design, Fabrication and Thrust/Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators Nguyen, Quang Sang Thesis of the Doctor of Philosophy Department of Advanced Technology Fusion Graduate School of Konkuk University Design, Fabrication and Thrust/Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators Nguyen, Quang Sang Thesis of the Doctor of Philosophy Department of Advanced Technology Fusion Graduate School of Konkuk University Design, Fabrication and Thrust/Drag Analysis of Improved Fish Robots Actuated by Piezoceramic Composite Actuators Nguyen, Quang Sang A Dissertation Submitted to the Department of Advanced Technology Fusion and the Graduate School of Konkuk University in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 2010 Approved by Park, Hoon Cheol Major Advisor Table of Content List of Figures v List of Tables ix ABSTRACT x Introduction 1.1 Understanding fish swimming 1.1.1 Reynolds number 1.1.2 Froude number: 1.1.3 Strouhal number 1.2 Overview of research on fish 1.3 Overview of research on fish robot driven by electromagnetic motor 1.4 Overview of fish robot driven by smart material 14 1.5 Objective and approach 21 A fish robot driven by piezoceramic actuators 24 2.1 Description of the fish robot 24 2.1.1 Actuator 25 2.1.2 Linkage design 26 2.1.3 External power supply 27 2.1.4 Miniaturized power supply 31 2.2 Swimming test 33 2.2.1 Linkage analysis 33 i 2.2.2 Thrust measurement 36 2.2.3 Wired-swimming test 38 2.2.4 Free-swimming test 38 2.3 2.3.1 Tail-beat angle 39 2.3.2 Thrust 40 2.3.3 Swimming speed 41 2.4 Experimental result 39 Summary 43 An improved fish robot driven by piezoceramic actuators 44 3.1 Design and fabrication of the actuation system 44 3.1.1 Actuator 44 3.1.2 Design and working principle of the linkage system 46 3.1.3 Linkage analysis 48 3.1.4 Fabrication of the actuation system 51 3.2 Fish robot configuration 52 3.2.1 Tail fin of the fish robot 52 3.2.2 Description of the improved fish robot 53 3.3 Evaluation of the improved fish robot 53 3.3.1 Tail-beat angle of the fish robot in water 54 3.3.2 Swimming test of the fish robot 55 3.3.3 Thrust of the fish robot 58 3.3.4 Thrust coefficient 62 3.3.5 Turning swimming radius of the fish robot 63 ii 3.4 3.4.1 Reynolds number 68 3.4.2 Froude number 68 3.4.3 Strouhal number 70 3.5 Summary 70 Thrust improvement by using Compressed LIPCAs 71 4.1 Fish robot 71 4.1.1 Actuator 71 4.1.2 Actuation mechanism 72 4.1.3 Fish body 72 4.2 Experiment 73 4.2.1 Swimming experiment 73 4.2.2 Thrust Measurement 77 4.2.3 Drag Estimation 77 4.3 Result 79 4.3.1 Swimming speed 79 4.3.2 Thrust of the Fish Robot 80 4.3.3 Drag of the Fish Robot 80 4.3.4 Drag coefficient 85 4.4 Parameter study 68 Summary 86 CFD simulation 87 5.1 Simulation model 87 5.2 Model validation 90 iii 5.3 Results and discussions 92 Concluding remarks and recommendations future work 100 6.1 Concluding remarks 100 6.2 Academic contribution 102 6.3 Recommendation for future work 103 REFERENCE 104 APPENDIX 107 요약문 108 iv List of Figures Figure 1-1: Fish configuration [2] Figure 1-2: Swimming mode associated with (a) BCF propulsion and (b) MPF propulsion [3] Figure 1-3: Diagram showing the relation between swimming propulsors and swimming functions [4] Figure 1-4: (a) The forces acting on a swimming fish; (b) Pitch, yaw, and roll definitions [5] Figure 1-5: Typical velocity of the largest possible variety of swimmers as a function of the Reynolds number [1] Figure 1-6: Flow visualization of velocity field in the x-y planes [13] 10 Figure 1-7: Viscous flow around a swimming fish: (a) mesh around the fish model; (b) detail of a cut through the mesh [14] 10 Figure 1-8: Schematic view of the eight internal links of the MIT’s Robot Tuna mechanism [18] 11 Figure 1-9: Draper Lab’s hydraulic-actuated Vorticity Control Unmanned Undersea Vehicle’s configuration [19] 11 Figure 1-10: RoboPike [20] 12 Figure 1-11: Design of Boxybot fish robot [21] 12 Figure 1-12: Prototype of the experimental robot fish [22] 13 Figure 1-13: Apparatus of pectoral fin motion [23] 13 Figure 1-14: Pressure sensor and its location on the fish body [24] 15 Figure 1-15: Drag measurement apparatus [25] 15 Figure 1-16: Geometry and position of neutral axis of LIPCA [28] 17 Figure 1-17: An IPMC strip under a low voltage [29] 17 Figure 1-18: Large actuation displacement and actuation force of SMA with low responsiveness [31] 18 Figure 1-19: Lamprey robot actuated by SMA [32] 18 v Figure 1-20: Two type robots driven by IPMC [33] 19 Figure 1-21: The tadpole robot: (a) configuration of the microrobot; (b) miniaturized of the battery, electrode and embedded controller located inside the body [34] 19 Figure 1-22: The floating boat driven by THUNDER [35] 20 Figure 1-23: Fish robot actuated by two LIPCA: (a) Configuration of the fish robot; (b) Linkage system 20 Figure 2-1: Assembly of the fish 25 Figure 2-2: Geometry and position of layers in a LIPCA 25 Figure 2-3: Linkage system of the fish robot 27 Figure 2-4: Function generator (Agilent 33220A) 29 Figure 2-5: Voltage amplifier (MATSUSADA model AML-1.5B40-LC) 29 Figure 2-6: Oscilloscope (Tektroniks TDS 2024) 29 Figure 2-7: The schematic of the MIPAD 30 Figure 2-8: Hardware implementation of the MIPAD 32 Figure 2-9: MIPAD response to square wave command 32 Figure 2-10: Tail-beat angle analysis by vector calculus 34 Figure 2-11: Tail-beat angle measurement apparatus 35 Figure 2-12: Load cell (Nano 17 Transducer) 36 Figure 2-13: The apparatus of the thrust measurement 37 Figure 2-14: Schematic diagram of the wired-swimming test 37 Figure 2-15: Fish robot in the free-swimming test 38 Figure 2-16: Tail-beat angle by vector calculus 40 Figure 2-17: Tail-beat angle of the fish robot in water 40 Figure 2-18: The average thrust of the fish robot 42 Figure 3-1: Fabricated LIPCA 45 Figure 3-2: Design of the actuation mechanism 45 Figure 3-3: Working principle of the actuation mechanism 47 Figure 3-4: Configuration of linkage system 49 vi