Springer Tracts in Advanced Robotics Volume 77 Editors: Bruno Siciliano · Oussama Khatib Satoshi Murata and Haruhisa Kurokawa Self-Organizing Robots ABC Professor Bruno Siciliano, Dipartimento di Informatica e Sistemistica, Università di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy, E-mail: [email protected] Professor Oussama Khatib, Artificial Intelligence Laboratory, Department of Computer Science, Stanford University, Stanford, CA 94305-9010, USA, E-mail: [email protected] Authors Prof. Satoshi Murata Dr. Haruhisa Kurokawa Tohoku University National Institute of Advanced Industrial Department of Bioengineering and Robotics Science and Technology (AIST) Graduate School of Engineering Intelligent Systems Institute 6-6-1 Aoba-yama, Sendai 980-8579 Field Robotics Research Group Japan 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 E-mail: [email protected] Japan E-mail: [email protected] Additional material to this book can be downloaded from http://extra.springer.com ISBN 978-4-431-54054-0 e-ISBN 978-4-431-54055-7 DOI 10.1007/978-4-431-54055-7 Springer Tracts in Advanced Robotics ISSN 1610-7438 Library of Congress Control Number: 2011942597 c Satoshi Murata and Haruhisa Kurokawa 2012 Original Japanese edition Jikososhiki Kikai System no Sekkeiron By Satoshi Murata and Haruhisa Kurokawa Copyright c 2009 by Satoshi Murata and Haruhisa Kurokawa Published by Ohmsha, Ltd. 3-1 Kanda Nishikicho, Chiyodaku, Tokyo 101-8460, Japan This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Typeset by Scientific Publishing Services Pvt. Ltd., Chennai, India. Printed on acid-free paper 543210 springer.com Editorial Advisory Board Oliver Brock, TU Berlin, Germany Herman Bruyninckx, KU Leuven, Belgium Raja Chatila, LAAS, France Henrik Christensen, Georgia Tech, USA Peter Corke, Queensland Univ. Technology, Australia Paolo Dario, Scuola S. Anna Pisa, Italy Rüdiger Dillmann, Univ. Karlsruhe, Germany Ken Goldberg, UC Berkeley, USA John Hollerbach, Univ. Utah, USA Makoto Kaneko, Osaka Univ., Japan Lydia Kavraki, Rice Univ., USA Vijay Kumar, Univ. Pennsylvania, USA Sukhan Lee, Sungkyunkwan Univ., Korea Frank Park, Seoul National Univ., Korea Tim Salcudean, Univ. British Columbia, Canada Roland Siegwart, ETH Zurich, Switzerland Gaurav Sukhatme, Univ. Southern California, USA Sebastian Thrun, Stanford Univ., USA Yangsheng Xu, Chinese Univ. Hong Kong, PRC Shin’ichi Yuta, Tsukuba Univ., Japan European * * * * * * * * * * * STAR (Springer Tracts in Advanced Robotics) has been promoted un- ROBOTICS* Research der the auspices of EURON (European Robotics Research Network) Network EURON Foreword Robotics is undergoing a major transformation in scope and dimension. From a largely dominant industrial focus, robotics is rapidly expanding into human envi- ronments and vigorously engaged in its new challenges. Interacting with, assisting, serving, and exploring with humans, the emerging robots will increasingly touch people and their lives. Beyond its impact on physical robots, the body of knowledge robotics has pro- duced is revealing a much wider range of applications reaching across diverse research areas and scientific disciplines, such as: biomechanics, haptics, neurosci- ences, virtual simulation, animation, surgery, and sensor networks among others. In return, the challenges of the new emerging areas are proving an abundant source of stimulation and insights for the field of robotics. It is indeed at the inter- section of disciplines that the most striking advances happen. The Springer Tracts in Advanced Robotics (STAR) is devoted to bringing to the research community the latest advances in the robotics field on the basis of their significance and quality. Through a wide and timely dissemination of critical re- search developments in robotics, our objective with this series is to promote more exchanges and collaborations among the researchers in the community and con- tribute to further advancements in this rapidly growing field. The monograph by Satoshi Murata and Haruhisa Kurokawa is an English trans- lation from a recently appeared book in Japanese on self-organizing mechanical systems. This is a relatively new area of research focusing on the realization of machines and robots, made to have a certain structure and functions, which are in- deed capable to adapt to unexpected situations, such as a misuse or a break-down, and ultimately reorganize themselves. As such, the book has a wide interest for scholars in the area of autonomous distributed systems, modular design and bio- logically-inspired robotics. Rich in examples and case studies, deep in the discussion of various issues in the implementation and instrumentation of self-organizing mechanical systems, this volume ambitiously aims at inspiring the designers of the next generation of robots. A very fine addition to the STAR series! Naples, Italy Bruno Siciliano August 2011 STAR Editor Preface* The notion of self-organization has recently been used in a variety of areas. It refers to the phenomenon in which an entity produces its own organization or structure by itself, just as biological organisms do. For example, seeds sown in the ground will sprout and leaves will grow. Then flowers will bloom, fruit will form, and finally seeds are reproduced. By simply putting the seed into the ground, it spontaneously becomes these things without any outside guidance. What an intriguing and fascinat- ing process! What, then, about machines? There has never been a machine that de- veloped by itself from a seed. Machines are built from many parts in factories using external forces. Instructions are given from the outside for each step of assembly. In short, machines are made to have a certain structure. These days, the machines we need in our everyday life have become more and more complicated. It now has become difficult to grasp every detail of these machines, and every detail of the mechanisms at work. Moreover, when those ma- chines break down or are used in unexpected manners, the behavior of the ma- chines can become unpredictable or in fact completely useless. In situations like this, one might hope that the machine would somehow adapt to the situation by reorganizing itself. This is where the notion of self-organizing mechanical systems comes in. It means changing from machines that are made to have a certain struc- ture and functions, to those that become reorganized in a desired way. Engineers have been learning from biology for a very long time. The drawing of flying machines by Leonardo da Vinci shows that research fields such as bio- mechanics and biomimetics have their origins back at least to that time. However, in order to create a machine that becomes properly organized, it is not sufficient to copy the appearance or the superficial mechanisms of biological organisms. It is necessary to understand the architecture and mechanisms behind the organisms that enable them to function. The theme of this book is to examine the feasibility of creating such artificial systems, namely self-organizing robots, the title of this book, within the limitations of current mechanical engineering. We have to con- sider how to construct such robots, and have to find possible applications for them. Robotics in general has many different aspects such as dynamics, fabrica- tion, control, electronic implementation, and software. In this book, in addition to * This book is an English translation of “Jiko-soshiki kikai sisutemu no sekkeiron (Design- ing self-organizing mechanical systems)” published in 2009 by Ohm-sha, Japan. Transla- tion and publication were supported by Grant-in-Aid for Publication of Scientific Research Result (No. 226006) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. X Preface these items, a robot is viewed as an autonomous distributed system. Taking this viewpoint, what needs to be considered to create robots that possess the capability of self-organization is discussed in detail. Here is an outline of the chapters: Chapter 1 describes the philosophy of design of self-organizing mechanical systems. The discussion here may seem a little ab- stract but it contains a simple introduction to the notion of autonomous distributed systems, which forms the basis of the concept of self-organization and self- organizing mechanical systems. Chapter 2 considers some examples of self- organization at various levels of hierarchy in biological systems, which is our source of inspiration when we design self-organizing machines and robots. Chapter 3 presents a history of the research related to self-organizing mechanical systems. Instead of providing a complete history, we present several selected topics suitable for grasping the flow of research in this area. Chapter 4 explains some mathematics and methodology necessary for understanding theoretical background to use self- organization phenomena. Chapter 5 demonstrates the feasibility of building a self- organizing machines by introducing an actual machine that is able to assemble it- self and repair