by Li Chi Keung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 95-100). / Acknowledgements --- p.ii / Abstract --- p.iii / Notations --- p.vii / List of Figures --- p.viii / List of Tables --- p.x / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Serial Manipulator and Parallel Manipulator --- p.1 / Chapter 1.2 --- Literature Overview --- p.4 / Chapter 1.3 --- Objective --- p.10 / Chapter Chapter 2 --- Classification and General Approach / Chapter 2.1 --- Overview --- p.11 / Chapter 2.2 --- Classification of Stewart Platform Type Parallel Manipulators --- p.12 / Chapter 2.3 --- Sub-structures of Stewart Platform Type Mechanism --- p.14 / Chapter 2.3.1 --- Point-Line (PL) Structure --- p.14 / Chapter 2.3.2 --- Point-Body (PB) Structure --- p.16 / Chapter 2.3.3 --- Line-Line (LL) Structure --- p.17 / Chapter 2.3.4 --- Line-Body (LB) Structure --- p.21 / Chapter 2.4 --- Approach for Closed-Form Direct Position Analysis --- p.25 / Chapter 2.4.1 --- DOF of Stewart Platform Type Parallel Mechanism --- p.26 / Chapter 2.4.2 --- DOF of Stewart Platform Type Parallel Mechanism with Disconnected Legs --- p.27 / Chapter 2.4.3 --- Formation of Rotation and Translation Matrices --- p.28 / Chapter 2.4.4 --- Formation of Closure Equations --- p.32 / Chapter 2.4.5 --- Elimination of Variables --- p.33 / Chapter 2.4.6 --- Final Solution --- p.35 / Chapter 2.5 --- Summary --- p.35 / Chapter Chapter 3 --- Case Studies / Chapter 3.1 --- Overview --- p.37 / Chapter 3.2 --- Type 5-5 Case II --- p.38 / Chapter 3.3 --- Type 6-5 --- p.47 / Chapter 3.4 --- Type 6-6 with 4 Collinear Joint Centers on Both Link (type 6-6 (L4L)) --- p.51 / Chapter 3.5 --- Type 6-6 with 4 Collinear Joint Centers on Movable Link (type 6-6 (L4B)) --- p.59 / Chapter 3.6 --- Summary --- p.63 / Chapter Chapter 4 --- Singularity Analysis / Chapter 4.2 --- General Theory --- p.64 / Chapter 4.2.1 --- Multiple Root Configuration --- p.64 / Chapter 4.2.2 --- Special Configuration --- p.66 / Chapter 4.2.3 --- Multiple Root Configuration and Special Configuration --- p.66 / Chapter 4.3 --- Examples --- p.66 / Chapter 4.3.2 --- Special Planar Parallel Manipulator --- p.66 / Chapter 4.3.4 --- Special Stewart Platform Type Parallel Manipulator --- p.71 / Chapter 4.4 --- Summary --- p.74 / Chapter Chapter 5 --- Conclusions and Recommendations for Future Research / Chapter 5.1 --- Conclusions --- p.75 / Chapter 5.2 --- Recommendations for Future Research --- p.77 / Appendices / Chapter A.l --- Direct Position Analysis of P5B Structure --- p.79 / Chapter A.2 --- Analytic Expressions for Symbols of Type 5-5 Case II --- p.82 / Chapter A.3 --- Analytic Expressions for Sybmols of Type 6-6 (L4L) --- p.84 / Chapter A.4 --- Mathematica Scripts for Case Studies in Chapter 3 --- p.85 / Chapter A.4.1 --- Type 5-5 Case II --- p.85 / Chapter A.4.2 --- Type 6-6 with 4 Collinear Joint Centers on Both Link Connected Together --- p.91 / Reference --- p.95

by Ho Siu Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 105-110). / ACKNOWLEDGEMENT --- p.i / ABSTRACT --- p.ii / NOMENCLATURE --- p.iii / TABLE OF CONTENTS --- p.v / LIST OF FIGURES --- p.vii / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 2 --- FORM-CLOSURE GRASP --- p.9 / Chapter 2.1 --- Condition for Form-closure Grasp --- p.9 / Chapter 2.2 --- Construction of Form-closure Grasp --- p.12 / Chapter 2.3 --- Configuration Stability of Form-closure Grasp --- p.28 / Chapter 2.4 --- Determination of Object Frame from a Form-closure Grasp --- p.33 / Chapter 3 --- DYNAMIC MODEL OF MULTI-ARM SYSTEMS HANDLING ONE OBJECT --- p.36 / Chapter 3.1 --- System Description --- p.36 / Chapter 3.2 --- Manipulator Dynamics --- p.37 / Chapter 3.3 --- Object Dynamics --- p.37 / Chapter 3.4 --- Contact Forces --- p.38 / Chapter 3.5 --- Kinematic Relations --- p.40 / Chapter 3.6 --- Overall System --- p.41 / Chapter 3.7 --- Constraint Space Matrices --- p.42 / Chapter 3.8 --- Motion Space Matrices --- p.48 / Chapter 3.9 --- General Joint Model --- p.54 / Chapter 4 --- FORWARD DYNAMICS OF MULTI-ARM SYSTEMS HANDLING ONE OBJECT --- p.65 / Chapter 4.1 --- Previous Works --- p.65 / Chapter 4.2 --- Modified Approach --- p.69 / Chapter 4.3 --- Constraint Violation Stabilization Method --- p.73 / Chapter 4.4 --- Computation Requirement of the Algorithm --- p.75 / Chapter 5 --- CONCLUSION --- p.78 / Chapter 5.1 --- Future Researches --- p.79 / APPENDICES / Chapter A --- PROOFS AND DISCUSSIONS RELATED TO CHAPTER TWO --- p.81 / Chapter B --- IMPLEMENTATION OF THE ALGORITHM FOR DETERMINING THE OBJECT FRAME FROM A FORM-CLOSURE GRASP --- p.95 / Chapter C --- EXPRESSING WRENCHES WITH ZERO-PITCH WRENCHES --- p.96 / Chapter D --- IMPLEMENTATION OF THE PROPOSED SIMULATION ALGORITHM --- p.98 / REFERENCES --- p.105

by Lam Pak Chio. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 101-105). / Abstract also in Chinese. / Abstract --- p.ii / Acknowledgements --- p.v / Contents / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Problem Definition and Approach --- p.3 / Chapter 1.3 --- Outline --- p.5 / Chapter 2 --- Algorithm Outline --- p.7 / Chapter 2.1 --- Introduction --- p.7 / Chapter 2.2 --- Assumptions --- p.7 / Chapter 2.3 --- Object Model --- p.8 / Chapter 2.4 --- Hand Model --- p.9 / Chapter 2.5 --- Measurement Data --- p.11 / Chapter 2.6 --- Algorithm Outline --- p.12 / Chapter 3 --- Calculation of Contact States --- p.14 / Chapter 3.1 --- Introduction --- p.14 / Chapter 3.2 --- Problem Analysis --- p.15 / Chapter 3.3 --- Details of Algorithm --- p.17 / Chapter 3.3.1 --- Calculation of Contact Points --- p.18 / Chapter 3.3.2 --- Calculation of Object Position and Orientation --- p.26 / Chapter 3.3.2.1 --- The Object Orientation --- p.26 / Chapter 3.3.2.2 --- The Object Position --- p.28 / Chapter 3.3.3 --- Contact Points on Other Fingers --- p.32 / Chapter 4 --- Calculation of Contact Motion --- p.34 / Chapter 4.1 --- Introduction --- p.34 / Chapter 4.2 --- Search-tree --- p.34 / Chapter 4.3 --- Cost Function --- p.36 / Chapter 4.4 --- Details of Algorithm --- p.37 / Chapter 4.4.1 --- Calculation of the Next Instant Contact States --- p.39 / Chapter 4.4.1.1 --- Contact Region Estimation --- p.41 / Chapter 4.4.1.2 --- Contact Point Calculation --- p.45 / Chapter 4.4.1.3 --- Object Position and Orientation Calculation --- p.48 / Chapter 4.4.1.4 --- Contact Motion Calculation --- p.50 / Chapter 5 --- Implementation --- p.56 / Chapter 5.1 --- Introduction --- p.56 / Chapter 5.2 --- Architecture of Friendly Teaching System --- p.56 / Chapter 5.2.1 --- CyberGlove --- p.57 / Chapter 5.2.2 --- CyberGlove Interface Unit --- p.57 / Chapter 5.2.3 --- Host Computer --- p.58 / Chapter 5.2.4 --- Software --- p.58 / Chapter 5.3 --- Algorithm Implementation --- p.59 / Chapter 5.4 --- Examples for Calculation of Contact Configuration --- p.59 / Chapter 5.5 --- Simulation --- p.68 / Chapter 5.6 --- Experiments --- p.82 / Chapter 5.6.1 --- Translation of an Object --- p.82 / Chapter 5.6.2 --- Rotation of an Object --- p.90 / Chapter 6 --- Conclusions --- p.98 / References --- p.101 / Appendix --- p.106

Ding Dan. / "October 2001." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 121-130). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Typescript. Includes bibliographical references (leaves 91-95).

Despite decades of research robotic manipulation systems outside of highly-structured industrial applications are still far from ubiquitous. Perhaps particularly curious is the fact that there appears to be a large divide between the theoretical grasp modeling literature and the practical manipulation community. Specifically, it appears that the most successful approaches to tasks such as pick-and-place or grasping in clutter are those that have opted for simple grippers or even suction systems instead of dexterous multi-fingered platforms. We argue that the reason for the success of these simple manipulation systemsis what we call passive stability: passive phenomena due to nonbackdrivable joints or underactuation allow for robust grasping without complex sensor feedback or controller design. While these effects are being leveraged to great effect, it appears the practical manipulation community lacks the tools to analyze them. In fact, we argue that the traditional grasp modeling theory assumes a complexity that most robotic hands do not possess and is therefore of limited applicability to the robotic hands commonly used today. We discuss these limitations of the existing grasp modeling literature and setout to develop our own tools for the analysis of passive effects in robotic grasping. We show that problems of this kind are difficult to solve due to the non-convexity of the Maximum Dissipation Principle (MDP), which is part of the Coulomb friction law. We show that for planar grasps the MDP can be decomposed into a number of piecewise convex problems, which can be solved for efficiently. Despite decades of research robotic manipulation systems outside of highlystructured industrial applications are still far from ubiquitous. Perhaps particularly curious is the fact that there appears to be a large divide between the theoretical grasp modeling literature and the practical manipulation community. Specifically, it appears that the most successful approaches to tasks such as pick-and-place or grasping in clutter are those that have opted for simple grippers or even suction systems instead of dexterous multi-fingered platforms. We argue that the reason for the success of these simple manipulation systemsis what we call passive stability: passive phenomena due to nonbackdrivable joints or underactuation allow for robust grasping without complex sensor feedback or controller design. While these effects are being leveraged to great effect, it appears the practical manipulation community lacks the tools to analyze them. In fact, we argue that the traditional grasp modeling theory assumes a complexity that most robotic hands do not possess and is therefore of limited applicability to the robotic hands commonly used today. We discuss these limitations of the existing grasp modeling literature and setout to develop our own tools for the analysis of passive effects in robotic grasping. We show that problems of this kind are difficult to solve due to the non-convexity of the Maximum Dissipation Principle (MDP), which is part of the Coulomb friction law. We show that for planar grasps the MDP can be decomposed into a number of piecewise convex problems, which can be solved for efficiently. We show that the number of these piecewise convex problems is quadratic in the number of contacts and develop a polynomial time algorithm for their enumeration. Thus, we present the first polynomial runtime algorithm for the determination of passive stability of planar grasps. For the spacial case we present the first grasp model that captures passive effects due to nonbackdrivable actuators and underactuation. Formulating the grasp model as a Mixed Integer Program we illustrate that a consequence of omitting the maximum dissipation principle from this formulation is the introduction of solutions that violate energy conservation laws and are thus unphysical. We propose a physically motivated iterative scheme to mitigate this effect and thus provide the first algorithm that allows for the determination of passive stability for spacial grasps with both fully actuated and underactuated robotic hands. We verify the accuracy of our predictions with experimental data and illustrate practical applications of our algorithm. We build upon this work and describe a convex relaxation of the Coulombfriction law and a successive hierarchical tightening approach that allows us to find solutions to the exact problem including the maximum dissipation principle. It is the first grasp stability method that allows for the efficient solution of the passive stability problem to arbitrary accuracy. The generality of our grasp model allows us to solve a wide variety of problems such as the computation of optimal actuator commands. This makes our framework a valuable tool for practical manipulation applications. Our work is relevant beyond robotic manipulation as it applies to the stability of any assembly of rigid bodies with frictional contacts, unilateral constraints and externally applied wrenches. Finally, we argue that with the advent of data-driven methods as well as theemergence of a new generation of highly sensorized hands there are opportunities for the application of the traditional grasp modeling theory to fields such as robotic in-hand manipulation through model-free reinforcement learning. We present a method that applies traditional grasp models to maintain quasi-static stability throughout a nominally model-free reinforcement learning task. We suggest that such methods can potentially reduce the sample complexity of reinforcement learning for in-hand manipulation.We show that the number of these piecewise convex problems is quadratic in the number of contacts and develop a polynomial time algorithm for their enumeration. Thus, we present the first polynomial runtime algorithm for the determination of passive stability of planar grasps.

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by Lam Miu-Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 64-67). / Abstracts in English and Chinese. / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- Mathematical Preliminaries and Problem Definition --- p.6 / Chapter 2.1 --- Grasp Synthesis in Discrete Domain / Chapter 2.2 --- Assumptions / Chapter 2.3 --- Frictionless Form-Closure Grasp / Chapter 2.4 --- Frictional Form-Closure Grasp / Chapter 2.5 --- Problem Definition / Chapter Chapter 3. --- A Qualitative Test Algorithm and a Local Search Algorithm --- p.18 / Chapter 3.1 --- A Qualitative Test Algorithm / Chapter 3.2 --- A Local Search Algorithm / Chapter 3.3 --- Grasp Planning under Kinematic Constraints / Chapter Chapter 4. --- A Divide-and-Conquer Technique --- p.29 / Chapter 4.1. --- Determining a Separating Hyperplane / Chapter 4.2. --- Divide-and-Conquer in Frictionless Case / Chapter 4.3. --- Divide-and-Conquer in Frictional Case / Chapter Chapter 5. --- Implementation and Examples --- p.40 / Chapter 6.1. --- Examples of Frictionless Grasps / Chapter 6.2. --- Examples of Frictional Grasps / Chapter 6.3. --- Examples of Grasps under Kinematic Constraints / Chapter Chapter 6. --- Conclusions --- p.62 / Bibliography --- p.64

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 112-121). Also available in electronic version.