Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Psychology. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND HUMANITIES. / Vita. / Includes bibliographies. / by Marc H. Raibert. / Ph.D.

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published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

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by Lo, Ka-wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 76-81 (2nd gp.)). / Acknowledgments --- p.i / Abstract --- p.ii / Notations --- p.iii / List of Figures --- p.v / List of Tables --- p.vii / Chapter 1. --- Introduction / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Literature Review --- p.4 / Chapter 1.3 --- Objective --- p.10 / Chapter 2. --- Comparison of Different Approaches / Chapter 2.1 --- Sample Manipulator --- p.11 / Chapter 2.1.1 --- Force Decomposition Method --- p.12 / Chapter 2.1.2 --- Forward Rate Kinematics Base Method --- p.15 / Chapter 2.1.3 --- Grassmann Geometry Method --- p.18 / Chapter 2.2 --- Comparison Criteria --- p.20 / Chapter 2.2.1 --- Computational Complexity --- p.20 / Chapter 2.2.2 --- Scope of Application --- p.22 / Chapter 2.3 --- Summary --- p.23 / Chapter 3. --- Enumeration of Configuration Singularity / Chapter 3.1 --- Novel 6 DOF --- p.25 / Chapter 3.1.1 --- Result Analysis --- p.31 / Chapter 3.2 --- A 3 DOF with Symmetric Base --- p.33 / Chapter 3.2.1 --- Result Analysis --- p.35 / Chapter 3.3 --- A 3 DOF with Non-Symmetric Base --- p.36 / Chapter 3.3.1 --- Result Analysis --- p.37 / Chapter 3.4 --- A New Model of 6-SPS Defined by Kong et al --- p.40 / Chapter 3.5 --- A New Class of 6-SPS Platform-Type Parallel Manipulator --- p.45 / Chapter 3.5.1 --- The Hexagonal Base --- p.46 / Chapter 3.5.2 --- The Pentagonal Base --- p.50 / Chapter 3.5.3 --- The Tetragonal Base --- p.52 / Chapter 3.5.4 --- The Triangular Base --- p.55 / Chapter 3.6 --- Summary --- p.59 / Chapter 4. --- Numerical Analysis / Chapter 4.1 --- Parameter Analysis --- p.60 / Chapter 4.1.1 --- One Unknown Variable --- p.61 / Chapter 4.1.2 --- Two Unknown Variables --- p.63 / Chapter 4.2 --- Critical Value of Ratio R/q --- p.69 / Chapter 4.3 --- Summary --- p.72 / Chapter 5. --- Conclusions and Future Work / Chapter 5.1 --- Conclusions --- p.73 / Chapter 5.2 --- Future Work --- p.75 / References --- p.76 / Appendix --- p.82

Chan, Ho Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 92-94). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.iii / ACKNOWLEDGEMENTS --- p.iv / PUBLISHED PAPERS --- p.vi / TABLE OF CONTENTS --- p.vii / LIST OF FIGURES --- p.ix / LIST OF TABLES --- p.xi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Traditional methods of cell manipulation --- p.1 / Chapter 1.2 --- New methods of cell manipulation using MEMS technology --- p.2 / Chapter 1.2.1 --- Electrostatic actuation --- p.2 / Chapter 1 2.2 --- Shape memory effect --- p.4 / Chapter 1.2.3 --- Pneumatic --- p.5 / Chapter 1.2.4 --- Electromagnetic --- p.5 / Chapter 1.2.5 --- Thermal --- p.6 / Chapter 1.3 --- Objective of this project --- p.1 / Chapter Chapter 2 --- Literature review --- p.11 / Chapter Chapter 3 --- "Design, modeling and heat transfer analysis" --- p.14 / Chapter 3.1 --- Design and the temperature-radius relationship of thermal actuators --- p.14 / Chapter 3.2 --- Heat transfer analysis --- p.17 / Chapter 3.2.1 --- Heat dissipation from the actuator --- p.18 / Chapter 3.2.2 --- Thermal transient response in liquid environment --- p.23 / Chapter 3.3 --- "Temperature, radius of curvature and tip deflection and actuation voltage relationship" --- p.24 / Chapter Chapter 4 --- Fabrication process of the thermal actuators --- p.28 / Chapter 4.1 --- Basic processes involved in fabricating the thermal actuators --- p.28 / Chapter 4.1.1 --- Photolithography --- p.28 / Chapter 4.1.1.1 --- Spin on and pattern photoresist --- p.29 / Chapter 4.1.1.2 --- Methods for alignment --- p.31 / Chapter 4.1.2 --- Lift off and etching processes --- p.33 / Chapter 4.1.3 --- Sacrificial release process --- p.35 / Chapter 4.1.4 --- Deposition --- p.38 / Chapter 4.1.4.1 --- Sputtering --- p.39 / Chapter 4.1.4.2 --- Thermal evaporation --- p.39 / Chapter 4.1.4.3 --- Thermal oxidation --- p.40 / Chapter 4.1.4.4 --- Parylene deposition --- p.41 / Chapter 4.2 --- Fabrication process of thermal actuators/grippers --- p.45 / Chapter 4.2.1 --- Fabrication of thermal actuators --- p.45 / Chapter 4.2.1.1 --- Mask design and making --- p.45 / Chapter 4.2.1.2 --- Process flow --- p.49 / Chapter 4.2.1.3 --- Fabricated samples --- p.53 / Chapter 4.2.1.4 --- Problems encountered during fabrication process --- p.54 / Chapter 4.2.2 --- Fabrication of multi-finger gripper --- p.55 / Chapter 4.2.2.1 --- Mask design --- p.55 / Chapter 4.2.2.2 --- Process flow --- p.57 / Chapter 4.2.2.3 --- Fabricated samples --- p.57 / Chapter Chapter 5 --- Testing thermal actuators --- p.58 / Chapter 5.1 --- Actuation by applying voltage (underwater) --- p.58 / Chapter 5.1.1 --- Experimental setup --- p.58 / Chapter 5.1.2 --- Experimental results --- p.59 / Chapter 5.1.3 --- Discussion --- p.63 / Chapter 5.2 --- Actuation by water bath heating --- p.66 / Chapter 5.2.1 --- Experimental setup --- p.66 / Chapter 5.2.2 --- Experimental results --- p.66 / Chapter 5.2.3 --- Discussion --- p.68 / Chapter 5.3 --- Frequency response and force analysis --- p.69 / Chapter 5.3.1 --- Frequency response --- p.69 / Chapter 5.3.2 --- Force analysis --- p.70 / Chapter Chapter 6 --- Cell grasping system --- p.73 / Chapter 6.1 --- Demonstration of cell grasping using single arm gripper --- p.73 / Chapter 6.2 --- MEMS chip with multi-finger grippers --- p.75 / Chapter 6.2.1 --- Mask design for MEMS chip --- p.76 / Chapter 6.2.2 --- Actuation of thermal gripper in air --- p.78 / Chapter 6.2.3 --- Demonstration of actuation and cell grasping --- p.79 / Chapter 6.2.4 --- A flexible cell grasping motion --- p.80 / Chapter 6.3 --- Proposed cell grasping system --- p.82 / Chapter Chapter 7 --- Summary and future work --- p.83 / Chapter 7.1 --- Summary --- p.83 / Chapter 7.2 --- Future work --- p.84 / APPENDIX --- p.87 / BIBLIOGRAPHY --- p.92

Methods for resolving kinematic redundancies of manipulators by the effect on joint torque are examined. When the generalized inverse is formulated in terms of accelerations and incorporated into the dynamics, the effect of redundancy resolution on joint torque can be directly reflected. One method chooses the joint acceleration null-space vector to minimize joint torque in a least squares sense; when the least squares is weighted by allowable torque range, the joint torques tend to be kept within their limits. Contrasting methods employing only the pseudoinverse with and without weighting by the inertia matrix are presented. The results show an unexpected stability problem during long trajectories for the null-space methods and for the inertia-weighted pseudoinverse method, but rarely for the unweighted pseudoinverse method. Evidently a whiplash action develops over time that thrusts the endpoint off the intended path, and extremely high torques are required to overcome these natural movement dynamics.

An improved robot manipulator decentralized non-linear adaptive controller that performs well in the presence of disturbances with unknown parameters and non-linearities is presented in this work. The proposed decentralized adaptive structure is a modification of the controller developed by Seraji [13-17] and is characterized by an auxiliary signal that compensates for the unmodeled dynamics and improves the tracking performance, by a feedforward component based on the inverse system to ensure high performance over a wide range and by a PD feedback component of constant gain to improve the speed of response of the system. As a result, a very accurate and fast path tracking is achieved despite the non-linearities. The scheme requires only the measurement of angular speed and displacement of each joint, and it does not require any knowledge about the mathematical model of the manipulator. Due to its decentralized structure, it can be implemented on parallel processors to speed up the operation. The main advantages of the proposed control scheme over similar controllers are that the control activity is smoother, it is less sensitive to sampling size and to the time period elapsed when the whole trajectory is traversed, as verified by simulations of several test conditions of-two of the joints of the PUMA 560 robot arm. / Graduation date: 1991

The development of modern industries calls for the robotic manipulators with high speed and accurate tracking performance. Many authors have paid attention to robust control of robotic manipulators; however, only few authors have also considered the control problem of manipulators with power limitation. In this dissertation, the robotic manipulator is modeled as an uncertain system, with such uncertainties as varying moments of inertia, damping and payloads during tracking. The resulting uncertain part of the system is norm-bounded by a known constant. The total control consists of a linear part with gain matrix K, and a nonlinear part Δv, typically used for control of uncertain dynamical systems. Saturation of the resulting controller is assumed, with bounds imposed by the power limitation of actuators. It is proved at the dissertation that such a system is globally uniformly practically stable. The distribution of the control power between two controllers is discussed. It is found that when small gain matrix K is used and Δv dominates the controller, the solution to the system can approach a smaller region with faster response; that is, higher tracking accuracy is obtained. Theoretical analysis is provided to support the proposed control scheme. A two-link robotic manipulator is simulated with the results confirming the prediction. / Graduation date: 1992