Table of Contents Introduction Historical Review of Robotic Orienting Devices Kinematic Position Analysis Instantaneous Kinematic Analysis

Transcription

1 Table of Contents 1 Introduction Background in Robotics Robot Mechanics Manipulator Kinematics and Dynamics Robot Architecture Robotic Wrists Origins of the Carpal Wrists Motivation for the New Wrist Outline of Contents 9 2 Historical Review of Robotic Orienting Devices Serial Configurations Parallel Configurations Parallel, Spherical Wrists Parallel, Spatial Wrists Analytical Methods 15 3 Kinematic Position Analysis Review of Similar Geometric Architectures Geometric Model of the Wrist Architecture Kinematic Position Analysis of Proposed Wrist Architecture Forward Kinematic Analysis Inverse Kinematic Analysis Artificially Coupled Spherical Configuration Kinematic Workspace Analysis Conclusions to Kinematic Position Analysis 25 4 Instantaneous Kinematic Analysis Discussion of Singularities Singularities in Current Robotic Wrists Discussion of Dexterity Closed-Form Jacobian Singularity Analysis Dexterity Analysis Dexterous Manipulator Workspace Approach to Dexterous Measure Definition of Dexterous Measure Application to Three Pointing Manipulators 38 iv

2 Stephen L. Canfield Contents v Carpal Wrist Serial Pitch-Yaw Wrist Spherical Five-Bar Pointer Dexterous Measure Results Conclusions 43 5 Dynamic Force Analysis Introduction to Dynamic Analysis Review of Research in Manipulator Dynamics Carpal Wrist Dynamics Review of Position Information Determining Tool Velocity Angular Velocity of the Distal Frame Translational Velocity of the Tool Center of Mass Lagrange s Equations for the Wrist-Isolated Problem Derivatives of Kinetic and Potential Energy Solving Lagrange s Equations Application to the Carpal Wrist Prototype Results and Conclusions 58 6 Dynamic Simulation Environment Introduction Wrist Dynamics Angular Velocity of the Distal Frame Translational Velocity of the Tool Center of Mass Lagrange s Equations for the Wrist-Isolated Problem Derivatives of Kinetic and Potential Energy Expanding the Equations of Motion Solving the Forward Dynamics Results and Conclusions 68 7 Application Issues Full Orientational Capability of the Carpal Wrist Redundancy Resolution Redundancy Resolution Literature Review Optimizing on Dexterity Optimizing for Mechanical Advantage Optimizing for Dynamic Performance Path Planning Path Planning Based on Input Torque Requirements / Constraints Optimal Path Planning Based on Input Torque Requirements 79

3 Stephen L. Canfield Contents vi 7.6 Summary of Application Issues 80 8 Conclusions and Recommendations Recommendations, Future Work 82 Bibliography 84 Appendix A: Carpal Wrist Prototype 90 Carpal Wrist Prototype Objectives 91 Kinematic Parameters 91 Strength Considerations 92 Actuation Scheme 92 Physical Design of Components 93 Legs 93 Base 94 Midplane Joints 94 Actuation 95 Pictorial Demonstration of Carpal Prototype 96

4 List of Figures 1.1 Kinematic Diagram of the Carpal Wrist CAD Model of the Carpal Wrist Prototype Photograph of the Carpal Wrist Prototype Gimbal Representing General Serial Wrists Cincinnati Milacron Three-Roll-Wrist Slim Wrist by Graco Robotics Inc Omni Wrist Parallel Spherical Manipulator Parallel, Spatial Manipulator Schematic of Double Octahedron Kinematic Diagram of Proposed Wrist Wrist Reference Frames Spherical Kinematic Model Theoretical Workspace Corresponding to Various R d Ratios Kinematic Diagram of the Carpal Wrist Midplane Normal Kinematic and Singular Workspace Boundaries Dexterity Measures Plotted Over an Angular Representation of the Workspace Determinant-Based Dexterity Plotted Over the Workspace for Multiple R d Ratios Serial Pitch-Yaw Wrist Spherical Five-Bar Pointer Minimum Dexterity Plot of the Carpal Robotic Wrist Minimum Dexterity Plot of the Serial Pitch-Yaw Wrist Minimum Dexterity Plot of the Spherical Five-Bar Linkage Carpal Wrist Kinematic Model Base and Distal Frame Assignment Orientation of Z axis of Distal Frame {D} Wrist Mounted Tool Dynamic Force Measurement System Gages on Actuating Rod Path Trajectory Plot for a Longitudinal Move Required Motor Moment Plots: Dynamic Model Actuator Rod Force: Dynamic Model Actuator Rod Force: Experimental Model 57 vii

5 Stephen L. Canfield List of Figures viii 6.1 Wrist Mounted Tool Conceptual Roll Axis Design Exploded View of Roll dof 72 A.1 Flowchart of Prototype Evolution 70 A.2 Prototype Carpal Wrist 91 A.3 Leg 93 A.4 Base 94 A.5 Midplane Joints 94 A.6 Actuation Components 95 Prototype Pictorial 96

6 List of Tables 1.1 Features of Alternative Manipulator Structures Combining Two Dexterity Measures Comparison of Singularity Measure and Kinematic Closure Results of the Dexterous Measure Evaluation Prototype Carpal Wrist Parameters for Dynamic Analysis 55 A.1 Kinematic Parameter Selection 92 ix