The Development of an Antagonistic SMA Actuation Technology for the Active Cancellation of ...

285 Pages·2010·6.35 MB·English

The Development of an Antagonistic SMA Actuation
Technology for the Active Cancellation of Human Tremor

by

Anupam Pathak

A dissertation submitted in partial fulfillment
of the requirements for the degree of
Doctor of Philosophy
(Mechanical Engineering)
in the University of Michigan
2010

Doctoral Committee:

Associate Professor Diann Erbschloe Brei, Co-Chair
Assistant Research Scientist Jonathan E. Luntz, Co-Chair
Associate Professor Brent Gillespie
Associate Professor John A. Shaw
© Anupam Pathak
All Rights Reserved
2010
Acknowledgements

I am sincerely grateful for my advisor, Diann Brei, who has offered her guidance
and support through my graduate school career and enabled me to complete this
dissertation. Diann’s mentorship helped to foster my creativity both as a researcher and
engineer, and she has always encouraged me to pursue new ideas and opportunities. I
have felt, among the rest of her students, a part of an extended family, which is
something I have always appreciated. Jon Luntz, my co-advisor, has also played a key
part in my work. I have been fortunate to experience his passion for technical
knowledge almost every day, and he has always encouraged me to have the confidence
to learn new topics, no matter how difficult they seem. My committee members, John
Shaw and Brent Gillespie have offered significant guidance in this process, for which I
am thankful. Several portions of this dissertation could not have been accomplished
without John Shaw’s help and the use of his experimental facilities.
My excellent science and math instructors in the past have collectively influenced
my pursuit of this dissertation through their guidance, and encouragement for personal
development. My Berkeley professors have all challenged me to learn, pursue research,
and attempt to solve the many social issues we experience today. I particularly want to
thank Benson Tongue my research advisor at Berkeley for his generous mentorship and
support, both past and present. His instruction helped me immensely, and his comedy
has taught me to enjoy life and stay optimistic.
I’d like to thank all of my friends all across the world for their support and
camaraderie, and I want to give a special thanks to the participants in the China EAPSI
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program for their interest and discussion regarding my research. My lab mates (past and
present) -- Paul Alexander, Jarod Kelly, Jim Otten, Monica Toma, Nathan Wilmot,
Brian Barnes, John Redmond, Julianna Abel, Brent Utter, Won Hee Kim, Shishira, and
Poorna Mane -- have all supported me along the way, and I have always enjoyed
sharing our common interests in creativity and invention.
Most importantly, I must acknowledge my family. I’m thankful for my
girlfriend Karolina who has supported me through this entire process, and served as an
inspiration through her love for learning, and her artistic creativity. She has been a
wonderful influence in my life. My two sisters, Smita and Shalini, who I love very
much, have always been proud and supportive of my endeavors and I am so lucky to
have them. My brilliant parents have been and continue to be role models that I aspire
to. Both my Mom and Dad have always offered unconditional love and support that has
enabled me to take risks in life and pursue areas I’m passionate about.

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Table of Contents

Page
Acknowledgements ............................................................................................................... ii

List of Figures ........................................................................................................... x

List of Tables .......................................................................................................... xvi

Abstract ................................................................................................................ xviii

Chapter 1: Introduction .............................................................................................. 1
1.1 Tremor ....................................................................................................... 3
1.1.1 Tremor Classifications .......................................................................................... 3
1.1.2 Tremor Motion Characteristics ............................................................................. 4
1.1.3 Treatments for Essential Tremor .......................................................................... 6
1.1.3.1 Pharmacological Treatments ............................................................................ 7
1.1.3.2 Surgical Treatments ......................................................................................... 7
1.1.3.3 Assistive Devices ............................................................................................. 8
1.1.4 Mitigation of Physiological Tremor ................................................................... 10
1.1.4.1 Medical Sector ............................................................................................... 11
1.1.4.2 Manufacturing Sector .................................................................................... 12
1.1.4.3 Military Sector ............................................................................................... 13
1.2 Classification of Tremor Reduction Approaches ....................................... 15
1.2.1 Isolation .............................................................................................................. 15
1.2.2 Suppression ......................................................................................................... 16
1.2.3 Active Cancellation ............................................................................................ 17
1.2.4 Summary and Downselection ............................................................................. 18
1.3 Actuator Selection for Active Cancellation ............................................... 20
1.3.1 Conventional Actuation vs. Smart Material Actuation ....................................... 21
1.3.2 Smart Materials ................................................................................................... 25
1.3.2.1 Magnetostrictors ............................................................................................ 25
1.3.2.2 Electrostrictors ............................................................................................... 26
1.3.2.3 Piezoelectrics ................................................................................................. 27
1.3.2.4 Shape Memory Alloys ................................................................................... 28
1.4 Shape Memory Alloy Background ........................................................... 29
1.4.1 History of Shape Memory Alloys ....................................................................... 30
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1.4.2 Shape Memory Phenomena ................................................................................ 31
1.4.2.1 Shape Memory Effect .................................................................................... 32
1.4.2.2 Pseudoelasticity ............................................................................................. 33
1.4.3 Applications ........................................................................................................ 34
1.4.3.1 Military and Aerospace .................................................................................. 34
1.4.3.2 Medical Field ................................................................................................. 35
1.4.3.3 Consumer Market .......................................................................................... 36
1.4.4 Antagonistic Architecture ................................................................................... 37
1.4.5 Research Issues ................................................................................................... 40
1.4.5.1 Cyclic Repeatability ....................................................................................... 40
1.4.5.2 Actuation Frequency ...................................................................................... 42
1.4.5.3 Prediction and Control ................................................................................... 43
1.5 Research Goals and Objectives ................................................................. 45
1.6 Research Approach .................................................................................. 45
1.6.1 The Study of Shakedown in the Quasi-Static Design of the SMA
Stabilizing Handgrip ........................................................................................... 46
1.6.2 Investigations of Convective Heat Transfer from SMA ..................................... 47
1.6.3 Transient Thermodynamic Modeling and Experimental Validation of
the Antagonistic SMA Actuation Architecture ................................................... 48
1.6.4 Dynamic Design of the Active Cancellation of Tremor System ........................ 48
1.7 Contributions ........................................................................................... 49

Chapter 2: The Study of Shakedown in the Design of the SMA Stabilizing Handgrip
............................................................................................................... 52
2.1 Dynamic Weapons Modeling ................................................................... 54
2.1.1 Generic Weapons Model .................................................................................... 55
2.1.1.1 System of Equations ...................................................................................... 58
2.1.1.2 Estimating Human Disturbances ................................................................... 61
2.1.1.3 Generation of Actuator Requirements ........................................................... 63
2.1.2 Weapon System Case Studies ............................................................................. 64
2.1.2.1 M24 Sniper Rifle ........................................................................................... 65
2.1.2.1.1 Human Disturbance Estimation........................................................................ 65
2.1.2.1.2 Actuator Requirements ..................................................................................... 66
2.1.2.2 M16 Assault Rifle ........................................................................................... 67
2.1.2.2.1 Human Disturbance Estimates ......................................................................... 68
2.1.2.2.2 Actuator Requirements ..................................................................................... 69
2.1.3 M16 Stabilizing Handgrip Specifications ........................................................... 70
2.2 Stacked Platform Design .......................................................................... 71
2.2.1 Architecture and Operation ................................................................................. 72
2.2.2 Loading Theory .................................................................................................. 73
2.3 Quasi-Static Design Methodology ............................................................ 75
2.3.1 Stabilizing Handgrip Prototype .......................................................................... 76
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2.3.2 Initial System Load Lines ................................................................................... 77
2.3.2.1 Experimental Setup and Procedure ................................................................ 77
2.3.2.2 Initial Azimuth Load Lines ............................................................................ 78
2.3.2.3 Initial Elevation Load Lines .......................................................................... 79
2.3.2.4 Pre-Shakedown SMA Load Lines ................................................................. 80
2.3.3 Post-Shakedown SMA Load Lines ..................................................................... 81
2.3.3.1 Shakedown Experimental Setup and Procedure ............................................ 81
2.3.3.2 SMA Shakedown Results and Empirical Modeling ...................................... 82
2.3.3.3 Post-Shakedown Material Characterization ................................................... 84
2.3.3.4 SMASH SMA Length Selection .................................................................... 84
2.4 Platform Characterization ......................................................................... 85
2.4.1 Quasi-Static Platform Performance .................................................................... 85
2.4.1.1 Azimuth Testing with Shaken Down Wire .................................................... 86
2.4.1.2 Elevation Testing with Shaken Down Wire ................................................... 87
2.4.2 Device Motion Performance ............................................................................... 88
2.4.2.1 Test Results .................................................................................................... 88
2.4.2.2 Spooling Effects ............................................................................................. 89
2.4.3 Dynamic Performance: Motion and Power Draw ............................................... 91
2.4.4 Feasibility Studies for Cancellation of Motion Disturbances ............................. 93
2.4.4.1 Initial Tremor Tests ....................................................................................... 94
2.4.4.1.1 Experimental Setup for Cancellation ............................................................... 94
2.4.4.2 Cancellation Trials ......................................................................................... 96
2.4.4.2.1 Square Wave Input ........................................................................................... 97
2.4.4.2.2 Smoothing Functions........................................................................................ 99
1 Hz .............................................................................................................................. 100
2 and 3 Hz ..................................................................................................................... 101
2.4.4.3 Smoothing Summary ................................................................................... 101
2.5 Conclusions ........................................................................................... 102

Chapter 3: Investigations of Convective Heat Transfer from SMA Wires............... 106
3.1 Transformation Strain Based Method for Convective Heat Transfer
Characterization of Shape Memory Alloy Wires .................................... 107
3.1.1 Transformation Strain to Temperature Correlation .......................................... 111
3.1.2 Transformation Strain Based Experimental Method ........................................ 113
3.1.2.1 Experimental Procedure ............................................................................... 114
3.1.2.2 Convection in Air......................................................................................... 115
3.1.2.2.1 Free Convection in Air ................................................................................... 115
3.1.2.2.1.1 Validation ................................................................................................ 116
3.1.2.2.1.2 Empirical Correlation .............................................................................. 119
3.1.2.2.2 Forced Convection in Air ............................................................................... 121
3.1.2.2.2.1 Empirical Correlation .............................................................................. 121
3.1.2.3 Free Convection in Mineral Oil ................................................................... 123
3.1.2.4 Effective Convection in Thermal Grease ..................................................... 124
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3.1.2.5 Free Convection in Water ............................................................................ 126
3.1.2.6 Comparison of Cooling Media .................................................................... 127
3.2 Carbon Nanotube (CNT) Fins for the Enhanced Cooling of Shape
Memory Alloy Wire .............................................................................. 129
3.2.1 CNT Growth ..................................................................................................... 131
3.2.2 Experimental Setup and Procedure ................................................................... 134
3.2.3 Results and Discussion ..................................................................................... 136
3.2.3.1 Cooling Model ............................................................................................. 137
3.2.3.2 Cooling Comparison .................................................................................... 139
3.3 Conclusions ........................................................................................... 140

Chapter 4: Transient Thermodynamic Modeling and Experimental Validation of an
Antagonistic SMA Actuation Architecture ........................................... 145
4.1 Model of SMA Wire in Antagonistic Architecture .................................. 147
4.1.1 SMA Modeling Background ............................................................................. 148
4.1.1.1 Empirical Modeling ..................................................................................... 149
4.1.1.2 Microstructure Modeling ............................................................................. 150
4.1.1.3 Thermomechanical Modeling ...................................................................... 150
4.1.2 Model Formulation ........................................................................................... 152
4.1.3 Antagonistic Compatibility Relations ............................................................... 155
4.1.3.1 Antagonistic Wire Taught ............................................................................ 156
4.1.3.2 Antagonistic Wire Slack .............................................................................. 157
4.1.4 Energy Balance and Convective Heat Transfer ................................................ 157
4.1.5 Solution Procedure for Transient Model .......................................................... 160
4.2 Experimental Validation of the Transient Thermodynamic Model .......... 161
4.2.1 Experimental Setup and Procedure ................................................................... 162
4.2.2 Model Analysis ................................................................................................. 164
4.2.2.1 Convective Coefficient ................................................................................ 165
4.2.2.2 Slack ............................................................................................................ 168
4.2.2.3 Boiling ......................................................................................................... 171
4.2.2.4 Friction ......................................................................................................... 171
4.2.2.5 Inertia ........................................................................................................... 172
4.2.2.6 Summary ...................................................................................................... 174
4.2.3 Varying Experimental Conditions .................................................................... 175
4.2.3.1 Frequency Tests ........................................................................................... 176
4.2.3.2 Partial Transformation Tests ........................................................................ 177
4.2.3.3 Duty Cycle Tests .......................................................................................... 180
4.2.3.4 Wire Diameter Tests .................................................................................... 182
4.3 Design Studies ....................................................................................... 184
4.3.1 Mechanical Advantage ..................................................................................... 185
4.3.2 Environmental Effects ...................................................................................... 188
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4.3.2.1 Convective Coefficient ................................................................................ 189
4.3.2.2 Ambient Temperature .................................................................................. 190
4.3.3 Duty Cycle ........................................................................................................ 192
4.3.4 Summary and Design Implications ................................................................... 196
4.4 Conclusions ........................................................................................... 198

Chapter 5: Dynamic Case-Study: The Active Cancellation of Tremor (ACT) System
............................................................................................................. 202
5.1 Handheld Tremor Cancellation Device ................................................... 203
5.1.1 ACT System Architecture and Operation ......................................................... 203
5.1.2 Motion Generating Platform Kinematics .......................................................... 205
5.1.3 ACT System Model Solution ............................................................................ 207
5.2 Parameter Analyses ................................................................................ 208
5.2.1 Assumptions ..................................................................................................... 208
5.2.1.1 Variables ...................................................................................................... 209
5.2.1.2 Constraints ................................................................................................... 210
5.2.2 Convective Coefficient ..................................................................................... 211
5.2.3 Diameter ........................................................................................................... 213
5.2.4 Length ............................................................................................................... 214
5.2.5 Controller Gain ................................................................................................. 215
5.2.6 Wire Angle ....................................................................................................... 217
5.3 Tremor Cancellation Device and Experiments ........................................ 220
5.3.1 ACT Prototype .................................................................................................. 220
5.3.2 Cancellation Test Procedure ............................................................................. 223
5.3.3 Single Frequency Testing ................................................................................. 223
5.3.4 Human Tremor Cancellation ............................................................................ 227
5.3.5 Power Consumption.......................................................................................... 229
5.4 Conclusions ........................................................................................... 230

Chapter 6: Conclusion ........................................................................................... 233
6.1 Contributions ......................................................................................... 234
6.1.1 Quasi-Static Design Accounting for Shakedown ............................................. 234
6.1.2 Investigation of Convective Heat Transfer ....................................................... 236
6.1.3 Thermodynamic Modeling ............................................................................... 239
6.1.4 ACT Case Study ............................................................................................... 241
6.1.5 Antagonistic SMA Actuator Characteristics and Design Strategies ................. 242
6.1.5.1 Environmental Conditions ........................................................................... 243
6.1.5.2 Geometric Properties ................................................................................... 245
6.1.5.3 Electric Heating Input .................................................................................. 247
6.2 Limitations and Future Work.................................................................. 248
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6.2.1 SMA Material ................................................................................................... 248
6.2.2 Cooling Techniques .......................................................................................... 249
6.2.3 Modeling ........................................................................................................... 250
6.2.4 Active Tremor Cancellation ............................................................................. 251
6.3 Future Applications and Spinoffs ........................................................... 252

References ............................................................................................................. 255

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