Dextrous Robot Hands

348 Pages·1990·15.811 MB·English

by  Mark R. Cutkosky, Robert D. Howe (auth.), Subramanian T. Venkataraman, Thea Iberall (eds.)

Dextrous Robot Hands
S.T. Venkataraman T. Iberall
Editors
Dextrous Robot Hands
With 95 Figures
Springer-Verlag
New York Berlin Heidelberg
London Paris Tokyo Hong Kong
Subramanian T Venkataraman
Jet Propulsion Laboratory
4800 Oak Grove Drive
Pasadena, CA 91109
USA
Thea Iberall
Center for Neural Engineering
Department of Computer Science
University of Southern California
Los Angeles, CA 90089
USA
Library of Congress Cataloging-in-Publication Data
Dextrous robot hands / edited by Subramanian T. Venkataraman. Thea
Iberall.
p. em.
"This book grew out of the Workshop on Dextrous Robot hands that
occurred at the 1988 IEEE Conference on Robotics and Automation in
Philadelphia ... co-sponsored by the IEEE Computer Society and the
Office of Naval Research"-Pref.
Includes bibliographical references.
ISBN-13: 978-1-4613-8976-7 e-ISBN-13: 978-1-4613-8974-3
DOl: 10.1007/978-1-4613-8974-3
1. Robotics-Congresses. 2. Manipulators (Mechanism)-Congresses.
I. Venkataraman, Subramanian T. II. Iberall, Thea. III. Workshop
on Dextrous Robot Hands (1988 : Philadelphia, Pa.) IV. IEEE International
Conference on Robotics and Automation (1988 : Philadelphia, Pa.)
V. IEEE Computer Society. VI. United States. Office of Naval
Research.
TJ211.D49 1990
629.8'92-dc20 89-21999
Cover illustration by Jacqueline Weir.
Printed on acid-free paper.
ID 1990 by Springer-Verlag New York Inc.
Sofl:cover reprint of the hardcover 1st edition 1990
All rights reserved. This work may not be translated or copied in whole or in part without
the written permission of the publisher (Springer-Verlag, 175 Fifth Avenue, New York, NY
10010, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use
in connection with any form of information storage and retrieval, electronic adaptation,
computer software, or by similar or dissimilar methodology now known or hereafter devel
oped is forbidden.
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even if the former are not especially identified, is not to be taken as a sign that such
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be used freely by anyone.
Camera-ready text prepared using LaTEX.
9 8 7 6 5 432 1
Preface
Dextrous manipulation has been a topic of interest in industrial assembly,
prosthetic hand design, and in the study of human movement. In recent
years, dextrous robot hands, developed in the United States, Europe, and
Japan, have become available as research tools. While significant progress
is being made in their design, construction, and low level control, the true
potential of dextrous mechanical hands has yet to be realized. Roboticists
are up against fundamental problems in developing algorithms for solving
real-time computations in multi-sensory processing and motor control.
One possible way to develop better dextrous robot hands is through the
study of human hands. After decades of research into the control problem
of human arm movement, motor behaviorists are discovering key features
of sensorimotor integration in the central nervous system. In a sense, they
are reverse engineering the controller of a highly versatile, multiple degree
of freedom, sensor-based 'machine', of the type that roboticists would love
to build.
The aim of this book is to explore parallels in sensorimotor integration
in dextrous robot and human hands. While it is a view of the state of
knowledge in 1989, we feel that one way the robotics community can design
and learn to control more sophisticated robot hands is for them to work
with motor behaviorists. As seen from some of the work presented in this
book, such alliances have already proven fruitful.
The significance of this text is that it brings together researchers in
dextrous manipulation, and is a generally accessible resource for both ex
perimentalists and engineers. In a computer science department, it would
be a good companion text for a graduate level course in robotics, as it deals
with integrating sensory information with motor control for performing a
task. It would be a useful resource for a mechanical engineering course in
robot hand design, as students could use it to gain insights into functional
requirements for a dextrous hand. However, a strong feature of the book is
that it could be used as a text for an interdisciplinary graduate course on
sensorimotor integration for both experimentalists and engineers.
This book grew out of the Workshop on Dextrous Robot Hands that
occurred at the 1988 IEEE Conference on Robotics and Automation in
Philadelphia, Pennsylvania. Highly successful, the workshop was attended
by over 150 people, and was co-sponsored by the IEEE Computer Society
and the Office of Naval Research.
The first part of the book focuses on the functionality of human hands,
discussing results from studies in prehension and apprehension. The first
four chapters describe models of human hand function and present evidence
VI Preface
for why these models are valid. It is interesting to note that knowledge
based expert systems are described in Chapters 1 and 4 for codifying those
models. The second part of the book focuses on control and computational
architectures needed for dextrous hands. Chapters 5 through 7 describe
architectural design decisions for three different robot hands: the Stan
ford/JPL hand, the Utah/MIT hand, and the Belgrade/USC hand. The
third part of the book focuses on the two key features relevant to the ac
tual usage of dextrous robot hands. Chapters 8 and 9 describe grasp and
manipulation planning algorithms, while the subsequent three chapters de
scribe the use of sensors in dextrous hand usage. The fourth part of the
book is an edited transcript of the panel discussion that occurred at the end
of the workshop. Emerging from the discussion was a clear sense that key
problems in dextrous robot hand development and control include hand ge
ometry, hand functionality, development and placement of sensors, sensory
fusion, and the need for better actuators. And while the psychologists were
able to offer ideas about how these are accomplished in human systems,
they stressed the need for better criteria for evaluating effective dextrous
robot hand design and sensorimotor control.
The ultimate goal of this book is to make the motor behaviorists' litera
ture more accessible to roboticists, and vice versa. The human brain solves
many motor problems in real-time and seemingly without much effort that
engineers would like their robots to solve. As well, psychologists could use
many of the tools that roboticists have developed for analyzing motor con
trol. Solving these fundamental engineering problems, and perhaps even
gaining insights into the human brain, will take a combined effort of re
searchers coming top-down from the task level and bottom-up from the
servo-control level. We hope that this book will facilitate interdisciplinary
communication and make a contribution toward advancing knowledge on
dextrous manipulation.
For their insights, and encouragement, we would like to thank Michael
Arbib, Ruzena Bajcsy, George Bekey, Alan Desrochers, Virginia Diggles
Buckles, Krithi Ramamritham, and Rukmini Vijaykumar. We would also
like to thank Harry Hayman of the IEEE Computer Society for his help
in assuring the success of the workshop, as well as Alan Meyrowitz of the
Office of Naval Research for his support. We thank E. Colleen Scott for
her assistance in manuscript preparation, and Jacqueline Weir for her own
artistic dexterity. Our special thanks to the authors for their invaluable
contributions and timeliness, and to our families for their constant encour
agement and support.
August 1989 SUBRAMANIAN T. VENKATARAMAN
Pasadena, California
THEA IBERALL
Los Angeles, California
Contents
Preface v
I Lessons Learned from Human Hand Studies 1
1 Human Grasp Choice and Robotic Grasp Analysis 5
Mark R. Cutkosky and Robert D. Howe
2 Opposition Space and Human Prehension 32
Thea Iberall and Christine L. MacKenzie
3 Coordination in Normal and Prosthetic Reaching 55
Alan M. Wing
4 Intelligent Exploration by the Human Hand 66
Roberta 1. Klatzky and Susan Lederman
II Dextrous Hand Control Architectures 83
5 A Task-Oriented Dextrous Manipulation Architecture 87
Subramanian T. Venkataraman and Damian M. Lyons
6 CONDOR: A Computational Architecture for Robots 117
Sundar Narasimhan, David M. Siegel and John M. Hollerbach
7 Control Architecture for the Belgrade/USC Hand 136
George A. Bekey, Rajko Tomovic, and Ilija Zeljkovic
III Lessons Learned from Dextrous Robot Hands 151
8 Issues in Dextrous Robot Hands 154
Zexiang Li and Shankar Sastry
viii Contents
9 Analysis of Multi-fingered Grasping and Manipulation 187
Tsuneo Yoshikawa and Kiyoshi Nagai
10 Tactile Sensing for Shape Interpretation 209
Ronald S. Fearing
11 Tactile Sensing and Control for the Utah/MIT Hand 239
Ian D. McCammon and Steve C. Jacobsen
12 A New Tactile Sensor Design based on Suspension-Shells267
Tokuji Okada
IV Panel Discussion 287
References 299
Author Index 319
Subject Index 325
Part I
Lessons Learned from
Human Hand Studies
Thea Iberall
For thousands of years, the human hand and its neural controller has
been a constant source of fascination to philosophers. Aristotle pointed out
that the hand can grasp a variety of weapons and tools, noting that:
". .. Nature has admirably contrived the actual shape of the hand
so as to fit in with this arrangement. It is not all of one piece,
but it branches into several pieces; which gives the possibility
of its coming together into one solid piece, whereas the reverse
order of events would be impossible. Also, it is possible to use
the pieces singly, or two at a time, or in various ways. Again,
the joints of the fingers are well constructed for taking hold of
things and for exerting pressure." - Aristotle, Parts of Animals,
IV, X.
From these philosophical underpinnings, it was not until the end of the
19th century that psychology distinguished itself as an exact science of
behavior [Schultz 1975]. Using carefully controlled observation and experi
mentation to study human behavior, tools, techniques, and methods have
been developed and further refined in order to achieve precision and objec
tivity in measurement. One of the earliest systematic studies of rapid arm
and finger movements was done by Robert Sessions Woodworth [1899],
who argued that not only must the response to a stimulus be considered,
but also the structure and condition of the organism doing the responding.
Combining introspection, observation, and experimentation, he described
goal-directed movements as being two-phased: an initial, ungoverned ad
justment followed by a final, controlled adjustment. In the first demonstra
tion of accuracy-speed measurements, he showed that visually-guided slow
movements were more accurate than fast ones or eyes-closed slow move
ments. These early experiments led to studies by other researchers that
addressed questions such as: how much time is needed for processing visual
feedback, what happens if visual feedback is distorted or suppressed, what
2 Iberall
happens if the target is moving, and what are the different contributions
of central and peripheral vision.
At the same time that the field of experimental psychology was emerging,
physiological experiments were being conducted that began to shed light
on tile neural control of movement [Schmidt 1982]. Dominating the early
work in this field, the physiologist Sir Charles Sherrington coined the term
proprioception for the collective position sense stemming from sensors in
the muscles, joints, and tendons. Ultimately, this work has led to questions
such as: in what frame of reference do movements occur, how does auto
matic regulation of movement occur, what happens when different parts of
the brain are lesioned, and what are the physical characteristics of muscle.
Today, these fields blend as tools and techniques for measurement become
more and more sophisticated, and the complexity of the central nervous
system realized. An important influence on today's current trend toward
understanding the processes that support movement came from the psy
chologist Ulric Neisser [1967]. As Schmidt [1982] points out, Neisser was
able to legitimize the study of underlying processes, which ultimately can
only be inferred from behavior and not directly observed.
Struggling to develop testable hypotheses for how the neural controller
might work, studies in motor behavior address many of the same problems
faced by roboticists: how does the brain coordinate multiple degree of free
dom limbs, how are sensors used and modalities integrated, how is sensory
information integrated with movement, how does stable grasping occur,
how does movement occur in spite of the complex forces acting on the sys
tem, how are objects perceived, and how does planning occur. A current
controversy facing the study of human movement, relevant to feedforward
and feedback robot control, is the question of the existence of motor pro
grams [Keele 1968]; that is, are skilled movements stored as a prestructured
set of muscle commands that are just read out as a movement sequence oc
curs? If so, how many patterns can the nervous system store? If not, what
are the underlying control mechanisms for movements that are too rapid
for feedback processing?
In this section, two important skills of the human hand are studied. The
first is prehension, or the hand's ability to grasp or take hold of objects. The
second is apprehension, or the hand's ability to understand through active
touch, or haptics. Both involve highly complex sensorimotor integration,
dexterity, compliance with the environment, and tactile sensibility. As well,
both involve two separate components: stabilization and exploration. In
apprehension, if the object is not stabilized (by the environment, by the
other hand, or even by fingers from the same hand), then there is a problem
with exploration: the fingers will push the object away. In prehension, forces
for stabilizing the object in the hand are applied in opposition to each
other; sensibility facilitates dextrous manipulation. Engineers interested in
understanding the dexterity of the human hand are encouraged to read
these four chapters carefully.
Lessons Learned from Human Hand Studies 3
As an introductory bridge between experimentalists and roboticists, the
first chapter is by Cutkosky and Howe. Being mechanical engineers, they
focus on the question of how to capture the skill of human prehension for
the design of robot hands. By studying single-handed operations in small
batch machining, a grasp taxonomy was constructed, extending earlier work
done in the medical literature. Using this taxonomy, an expert system was
then developed that attempts to duplicate the human brain's ability to
choose a grasp posture given the necessary task and object parameters.
An important result of their work is that they can tie analytic approaches
to prehension with more abstract notions of human prehensile tasks. For
readers interested in exploring the details of the analytic approaches, Chap
ters 8 and 9 are excellent sources.
Taking a less reductionist approach, in Chapter 2 Iberall and MacKenzie
look carefully at human prehension in order to identify all its complexity.
Pointing out that numerous constraints act upon this skill, they put to
gether a comprehensive picture, drawing on current knowledge from hand
anatomy, biomechanics, sensory physiology, perception of object proper
ties, and task functionality. In order to relate this picture to dextrous robot
hands, they argue that the asymmetries in the human hand, in terms of
its structure, motor control, functionality, and distribution of sensors, are
an important lesson to be learned from nature. In addition, they present
an abstracted 'machine-independent' view of prehension that could map
either into robot hands or human hands.
In Chapter 3, Wing follows the Woodworth tradition and looks at human
prehensile movements when constrained to occur under conditions of sen
sory deficit. Reminiscent of non-sensor-based robot control, this situation
arises in human motor behavior when visual information is lacking (due
to rapidity of movement or eyes-closed conditions) or when proprioceptive
information is affected (as in the use of prostheses without proprioceptive
feedback). Ultimately, Wing shows that human prehension involves aspects
of stabilization and exploration, and argues that engineers should take into
account some of the underlying motor control processes in their designs of
prosthetic devices. Related to this is an important point about variability:
in robot control, engineers want to reduce variability in order to achieve
absolute repeatability; however, in human movement, variability is an im
portant feature, with the brain compensating as necessary to cope with a
variety of uncertainties in order to ensure success in the task.
In the last chapter of this section, Klatzky and Lederman ask the ques
tion "What determines the next hand movement?" Unfortunately for en
gineers, they show that there is no one simple answer to this question.
Coming from the tradition of psychophysics where researchers attempt to
catalogue sensations and measure discrimination thresholds, Klatzky and
Lederman systematically identify the components of object perception. In
a concise overview of their research, they offer a theoretical model as well
as their empirical evidence for how humans explore their environment. Ob-