Table Of ContentCISM COURSES AND LECTURES
Series Editors:
The Rectors
Manuel Garcia Velarde - Madrid
Jean Salen<;on - Palaiseau
Wilhelm Schneider -Wien
The Secretary General
Bernhard Schrefter - Padua
Executive Editor
Carlo Tasso - Udine
The series presents lecture notes, monographs, edited works and
proceedings in the field of Mechanics, Engineering, Computer Science
and Applied Mathematics.
Purpose of the series is to make known in the international scientific
and technical community results obtained in some of the activities
organized by CISM, the International Centre for Mechanical Sciences.
INTERNATIONAL CENTRE FOR MECHANICAL SCIENCES
COURSES AND LECTURES -No. 467
. ....rV'V1h.
~~~
~
~TV\~
."LLW"
WALKING: BIOLOGICAL AND
TECHNOLOGICAL ASPECTS
EDITED BY
FRIEDRICH PFEIFFER
TECHNICAL UNIVERSITY OF MUNICH
TERESA ZIELINSKA
WARSAW UNIVERSITY OF TECHNOLOGY
~
( Springer-Verlag Wien GmbH
The publication of this volume was co-sponsored and co-financed by the UNESCO Venice
Office -Regional Bureau for Science in Europe (ROSTE) and its content corresponds to a
CISM Advanced Course supported by the same UNESCO Regional Bureau.
This volume contains 141 illustrations
This work is subject to copyright.
All rights are reserved,
whether the whole or part of the material is concerned
specifically those of translation, reprinting, re-use of illustrations,
broadcasting, reproduction by photocopying machine
or similar means, and storage in data banks.
© 2004 by Springer-Verlag Wien
Originally published by Springer-Verlag Wien New York in 2004
SPIN 11012412
In order to make this volume available as economically and as
rapidly as possible the authors' typescripts have been
reproduced in their original forms. This method unfortunately
has its typographical limitations but it is hoped that they in no
way distract the reader.
ISBN 978-3-211-22134-1 ISBN 978-3-7091-2772-8 (eBook)
DOI 10.1007/978-3-7091-2772-8
PREFACE
Walking is a most ingenious invention of nature. It is versatile, flexible and
perfectly adapted to a natural environments, ranging from sand to ice, from large
plains to high mountains and from grass to woods. Walking in its various forms
enables biological systems access to the wealth of structures that exist on the earth
and to transform it to a rich and nearly infinitely varying theater of life. Walking
performance requires a large and diverse set of structures including legs, muscles,
sensors, signal processing lines, nerves and brains. Together, these components
generate motion of the complete biological system. Walking realizes motion, and
some biologists feel that motion planning is a form of intelligence. If intelligence
is defined as the ability to deal with unknown and new situations, such as the
possibility to find solutions for new problems, biological movement, both mental
and physical, can be consider-ed as a manifestation of intelligence. Therefore,
motion and intelligence might be regarded as the prerequisites for animals and
men to succeed in the various environmental niches that make up the earth.
Walking machines have been worked on by engineers for many years. In
primitive times, numerous trials had been made to realize some mechanisms with
walking capabilities. Nowadays the computer age and a large variety of sophisti
cated technologies give walking machine realizations a high probability of success.
Up to now the most vehicles coming out of the technical world are based mainly
on wheels, a truly human artifact. But cars, trains, ships or airplanes, all need
highly organized areas, at least for starting and landing. They need roads, tracks,
harbors, airports, which might be seen as a price for high speed and comfort. Ac
cess to non-organized areas of the ear-th is still difficult, even today. As successful
as wheeled devices are on the road, they cannot compare to legged locomotion of
animals on complex natural terrain or in disaster areas such as those that exist
after an earthquake or explosion.
Most walking machines take some biological systems as templates, with two,
four or with six legs. This makes sense, because natural evolution has created
a large variety of excellent solutions, within the evolutionary constraints of his
tory and biological development. For several reasons it makes no sense to copy
biology precisely. Evolution had to find its solutions within the framework of 'its
possibilities: no wheels, muscles instead of rotating motors, nerves with synapses
instead of wires and various types of sensors on a biological analogue basis. How
ever-, the number of sensors applied is sometimes extremely large. For example,
one antenna of a cockroach includes approximately 300,000 sensors! But on the
other hand technology can offer some positive constructive solutions: computer
and computer science, a sophisticated design methodology, excellent motor-gear
combinations with a high power to weight ratio, a highly developed sensor technol
ogy and very advanced light-weight solutions. Design should be minimalist in the
sense of Saint-Exupery: every part necessary for realizing certain functionality
should be included but not one more.
An intelligent strategy would combine the design principles of biological evolu
tion with the best of technological possibilities. This results in two requirements.
Firstly, biological research should be able to depict as many design principles in
vented by biological evolution as possible. Secondly, technology should make fea
sible the application of the most advanced software and hardware available with
respect to cognition, mechanics, sensors and actuator control. The realization of
a truly efficient walking machine is an enormous challenge that would, in itself,
push technology to its limit.
Beyond various applications addressed in this book there exists another im
portant aspect. Walking machines related to biological systems might serve as
hardware models on which biologists and physicians could test hypotheses on open
new questions concerning control of walking. Such tests represents a unique a
challenge in itself. The machines used for this purpose must be designed in a
way that allows for easy exchange of components, mainly components related to
control and "intelligence", i.e. sensors, computers and computer software. This
requires a special machine design, which is not easily realized.
Various aspects of the above problems were presented and discussed during
a CISM -Course on "Walking- Biological and Technological Aspects" in Udine,
Italy, from September 8 to 12, 2003. "Matus est Vita", the motto of CISM, fitted
perfectly to this Course. We are grateful to CISM to have enabled this Course,
and we thank all lecturers and participants taking part in the meeting.
Friedrich Pfeiffer
Teresa Zielinska
CONTENTS
Preface
Biological Aspects of Locomotion
by T. Zielinska ............................................................................................................... l
Locomotion in Complex Terrain
by R. E. Ritzmann and R. D. Quinn ............................................................................ 31
Evolution ofVertebrate Locomotory Systems
by M S. Fischer and H F. Witte ................................................................................ 51
WalkNet-a Decentralized Architecture for the Control of Walking Behaviour
Based on Insect Studies
by H Cruse, B. Blasing, J Dean, V. Dilrr, T. Kindermann,
J Schmitz, M Schumm ............................................................................................... 81
Technological Aspects of Walking
by F. Pfeiffer ............................................................................................................. 119
Motion Synthesis
by T. Zielinska ........................................................................................................... 155
Biological Aspects of Locomotion
Teresa Zielinska *
Department of Power and Mechanical Engineering, Warsaw University of Technology, Warsaw,
Poland, e-mail:teresaz@meil. pw .edu. pl
1 First Biologically Inspired Walking Machines
Since antiquity people have been fascinated by legged locomotion. This fascination has
been reflected in mythology. According to the books of Iliad, written by Homer (VIII
BC), one of the Greek gods built diverse walking devices. Some of them were human-like.
In the old scripts from India we can find descriptions of mechanical elephants. In Egyp
tian pyramids archaeologists identified a wooden dog (toy) dated from the XX century
BC. Mimicking human or animal motion started with the decoration of water organs and
*Acknowledgements: This work was supported by statutory funds of Institute of Aeronautics
and Applied Mechanics. Author would like to thank Dr.R.Ritzmann for professional review of the
text.
Figure 1. Model of the leg with 10 Figure 2. Model of running wooden
links horse
2 T. Zielinska
support phase
Figure 4. Model of a walking
Figure 3. Leg-end trajectory machine with 4-link legs (Chen
Paihung)
water clocks with moving figures. The precursor of the inventors of this type of devices
was Ctesibius, who worked in Alexandria circa 270 BC. His student, Philo of Byzantium,
wrote (circa 200 BC) the Mechanical Collection in which he described his teacher's in
ventions. The continuation of these works can be found in Hero's of Alexandra (I century
AD): Treatise on hydraulics, Treatise on pneumatics, and Treatise on mechanics.
He can be named the precursor of entertainment robots, due to his theaters with moving
figures. According to many old Chinese scripts, e.g. the Romance of Three Kingdoms
(written in XIV AD) describing Shu, Wei and Wu kingdoms, about 2400 years ago in
Shu region (southwest part of actual China), a wooden walking machine was build. The
machine was called Mu Niu Liu Ma (in Chinese MU means wooden, MA means horse,
NIU means cow, in free translation it is a device as powerful as a horse and as fast
as a cow), it was designed under the supervision of a Chinese officer Zhu Ge-Liang in
the frame of preparation for the war against Wei kingdom located in the central part of
current China. Mu Nu Liu Ma was used as a wheelbarrow for transportation of food
supplies needed by the army. The machine was able to cover a distance of 10 km in a day
in an undulating terrain carrying a load of 200-250kG. This story was recorded, but no
author supplied the information about the design details. Probably, thanks to the com
plex mechanism incorporating wooden gears, the machine - when pushed - transferred
its legs in a sequence similar to the sequence of motions of a cow or a horse when moving
slowly. This story fascinated many researchers interested in walking machines who tried
to reconstruct the device. Reconstruction done by Wan Jian from Xinjiang Institute of
Technology (XX c) is one of the most well known.
This prototype is probably the most complex one, each leg consist of 10 links (Figure 1).
Work on a copy of Mu Niu Liu Ma was also done in Taiwan. The investigations resulted
in several prototypes resembling the horses or cows. Following the work of Wang Jian,
Chiu Chengping from Taiwan elaborated a proposal of Mu Niu Liu Ma with similar leg
structure. Figure 2 illustrates the legs positions during motion of the proposed mecha-
Biological Aspects of Locomotion 3
Figure 5. Another version of Mu Niu Figure 6. Steam engme with
Liu Ma (according to Shen Huanwen legs
and Kwang Kai)
nism. The size and proportions of the mechanical components is chosen on such a way
that the leg-end trajectories are similar to the trajectories produced by walking animals
(Figure 3). Chen Paihung suggested the leg design with 4 links (Figure 4). Models build
by Shen Huanwen and Kwang Kai (Figure 5) uses a similar idea. In Mu Niu Liu Ma
reconstructions the key question is how did the mechanism work? This problem was
studied by Wang Jian and others. In several models proper leg movement was obtained
by the careful choice of lengths of leg links and the special design of mechanical con
nections between them. Wang Jian's prototype was of a size of a real animal and when
pushed transferred the legs keeping stable posture. Unfortunately the internal structure
of ancient Mu Niu Liu Ma is not know.
In more recent times with the advent of precision mechanics, many sophisticated
moving mechanisms were build, e.g. mechanical dolls built in the XVIII c. by Swiss
watch-makers: Pierre Jaquet-Droz, Jean Frederic Leschat, Henri Jaquet-Droz and Henri
Millarde. The device designed at the turn of the XVIII and XIX c. by Branton (Milonov
Ju.K. (1936)) should also be mentioned. This steam engine vehicle was supported
by wheels, but it also had two legs (see Figure 6). The legs helped to initiate the
motion which was difficult due to low friction between the wheels and rails (at that
time the friction phenomena were not well identified). To overcome the problem with
initiating motion, extra legs were added to push the vehicle. Another steam engine
with legs was the so called Blueprint vehicle (XVIII c.) (the name of the designer is
not known), here the wheels were used only for support and legs powered the motion.
Another interesting design was a four-legged "feet-walking machine" designed by the
famous Russian mathematician and mechanical engineer P.L.Tchebychev (1821-1899)
