Mechanics and Control of Soft-fingered Manipulation

by Inoue, Takahiro; Hirai, Shinichi

• ISBN13: 9781848009806
• ISBN10: 1848009801
• Format: Hardcover
• Copyright: 2008-11-01
• Publisher: Springer Verlag

Summary

"It is well known that the anatomy of our fingers, which consists of soft fingertips and hard fingernails, is well designed for grasping and manipulating objects. Mechanics and Control of Soft-fingered Manipulation introduces a new approach to the modeling of fingertips that have a soft pad and a hard back plate, similar to human fingers. Starting from the observation of soft-fingered grasping and manipulation, the book provides a parallel distributed model that takes into account tangential deformation of the fingertips. The model is supported with many experimental verifications and simulation results. Statics and dynamics in soft-fingered grasping and manipulation are also formulated based on this new model." "Mechanics and Control of Soft-fingered Manipulation uniquely investigates how soft fingertips with hard back plates enhance dexterity in grasping and manipulation, theoretically and experimentally. This approach reveals the differences between soft-fingered and rigid-fingered manipulation. Researchers involved in object manipulation by robotic hands, as well as in human dexterity in object manipulation, will find this text enlightening."--BOOK JACKET.

Table of Contents

Introduction	p. 1
Goal	p. 1
A Brief History of Articulated Robot Hands	p. 2
The 1970s	p. 2
The 1980s	p. 4
Overview	p. 11
Observation of Soft-fingered Grasping and Manipulation	p. 13
Introduction	p. 13
Object Pinching by a Pair of 1-DOF Fingers	p. 14
Rotation of a Pinched Object by External Force	p. 16
Concluding Remarks	p. 17
Elastic Model of a Deformable Fingertip	p. 19
Introduction	p. 19
Static Elastic Model of a Hemispherical Soft Fingertip	p. 21
Fingertip Stiffness	p. 21
Elastic Force	p. 24
Elastic Potential Energy	p. 25
Relationship Between Elastic Force and Elastic Energy	p. 25
Comparison with Hertzian Contact	p. 27
Measurement of Young's Modulus	p. 28
Compression Test	p. 29
Concluding Remarks	p. 32
Fingertip Model with Tangential Deformation	p. 33
Introduction	p. 33
Two-dimensional Elastic Energy Model	p. 34
Derivation of the Energy Equation	p. 34
Local Minimum of Elastic Potential Energy (LMEE)	p. 36
Restoring Moment for a Contacted Object	p. 37
Boundary Condition of Slip Motion	p. 38
Formulation of Geometric Constraints	p. 39
Normal Constraints	p. 39
Tangential Constraints	p. 40
LMEE with Constraints (LMEEwC)	p. 43
Concluding Remarks	p. 43
Variational Formulations in Mechanics	p. 45
Introduction	p. 45
Variational Principles	p. 45
Variational Principle in Statics	p. 45
Variational Principle in Dynamics	p. 48
Numerical Optimization of Energy Functions	p. 51
Nelder-Mead Method	p. 51
Multiplier Method	p. 55
Numerical Integration of Equations of Motion	p. 60
Runge-Kutta Method	p. 60
Constraint Stabilization Method	p. 63
Stabilization of Pfaffian Constraints	p. 66
Concluding Remarks	p. 70
Statics of Soft-fingered Grasping and Manipulation	p. 71
Introduction	p. 71
Static Analysis Based on Force/Moment Equilibrium	p. 71
Internal Energy Function	p. 71
Numerical Analysis	p. 72
Simulation	p. 72
Analysis Without Gravity	p. 72
Analysis Under Gravity	p. 75
Degrees of Freedom Desired for Stable Manipulation	p. 78
Experiments	p. 78
Concluding Remarks	p. 81
Dynamics of Soft-fingered Grasping and Manipulation	p. 83
Introduction	p. 83
Dynamics of Soft-fingered Grasping and Manipulation	p. 83
Simulation of Soft-fingered Grasping and Manipulation	p. 86
Numerical Integration of Lagrange Equations of Motion Under Geometric Constraints	p. 86
Computation of Equations of Motion	p. 87
Simulation Results	p. 91
Experimental Results	p. 95
Discussion	p. 98
Conclusion and Research Perspective	p. 98
Control of Soft-fingered Grasping and Manipulation	p. 101
Introduction	p. 101
Equations of Motion of the Two-fingered Hand	p. 102
Simulations I: Posture Control of a Grasped Object	p. 103
Serially-coupled Two-phased Object Orientation Controller	p. 103
Examples of Failure	p. 106
Available Range of the Biased Torque	p. 108
Passivity Analysis	p. 111
Simulations II: Responses for Time Delay	p. 113
Experiments I: Posture Control of a Grasped Object	p. 118
Object Orientation Control Under Constant Biased Torque (Exp. 1)	p. 119
Open-loop Control of Biased Torque (Exp. 2)	p. 121
Object Orientation Control Under Variable Biased Torque (Exp. 3)	p. 121
Experiments II: Responses for Time Delay	p. 124
Concluding Remarks	p. 132
Geometric and Material Nonlinear Elastic Model	p. 135
Introduction	p. 135
Hertzian Contact and Kao's Elastic Model	p. 135
Identification of Nonlinear Young's Modulus	p. 136
Comparison with Hertzian Contact	p. 138
Force Comparison	p. 139
Concluding Remarks	p. 141
Non-Jacobian Control of Robotic Pinch Tasks	p. 143
Introduction	p. 143
Kinematic Thumb Models in Previous Studies	p. 144
Equations of Motion	p. 147
Simulations	p. 149
A Serial Two-phased Controller	p. 149
Revolute Joint vs. Prismatic Joint (RP Joints)	p. 150
Revolute Joint vs. Revolute Joint (RR Joints)	p. 162
Prismatic 1-DOF Hand (P Joint)	p. 167
Rotational 1-DOF Hand (R Joint)	p. 169
Observations and Discussions	p. 181
Concluding Remarks	p. 183
Three-dimensional Grasping and Manipulation	p. 185
Introduction	p. 185
Quaternions	p. 185
Spatial Geometric Constraints Between an Object and a Fingertip	p. 192
Potential Energy of a Fingertip in Three-dimensional Grasping	p. 197
Grasping and Manipulation by Three 1-DOF Fingers	p. 201
Observation	p. 201
Mathematical Description	p. 202
Lagrange Equations of Motion	p. 207
Simulation	p. 214
Concluding Remarks	p. 217
Conclusions	p. 219
Main Contribution	p. 219
Future Work	p. 221
Static Modeling of Fingertips	p. 223
Contact Plane Formula	p. 223
Spring Constant Formulation	p. 223
Coordinate Conversion to Derive Fingertip Stiffness	p. 224
Approximation Method for a Nonlinear Curve	p. 226
Three-dimensional Modeling of Fingertips	p. 229
Derivatives of Angular Velocity Matrix	p. 229
Bilinear Form of the Outer Product Matrix	p. 230
Derivatives of Relative Angle with Respect to Quaternion Elements	p. 231
Derivatives of Relative Angle with Respect to Finger Angle	p. 232
Derivative of the Arctangent Function	p. 233
References	p. 235
Index	p. 243
Table of Contents provided by Ingram. All Rights Reserved.