Multibody System Simulation

... users on the other side of the fence ... have long said that until we numerical analysts take time to write good software and get it out to the users, our ideas will not be put into action. -C.W. GEAR IN [AIKE85] This monograph is based on my doctoral thesis which I wrote dur ing my work at the Interdisciplinary Center for Scientific Computing (IWR) at the Ruprecht-Karls University of Heidelberg. One of my intentions was and still is to stress the practical aspects leading from the conception of mathematical methods to their effective and efficient realization as scientific software. In my own experience, I had always wished there had been something to guide me through this engineering process which accompanies the basic research for which there were nu merous treatises dealing, e.g., with mathematical theory for descriptor systems. Therefore, I felt that writing this monograph provided a good op portunity to try to fill this gap by looking at software engineering from a scientific computing angle. Thus, this monograph contains a chap ter on software engineering with numerous examples from the work on MBSSIM. This is meant as a beacon for those of us who really do want to produce scientific software instead of just hacking some code. On the other hand, for those more interested in the theory of differential-algebraic equations, many bibliographical references have been included where appropriate.

The German Research Council (DFG) decided 1987 to establish a nationwide five year research project devoted to dynamics of multibody systems. In this project universities and research centers cooperated with the goal to develop a general pur pose multibody system software package. This concept provides the opportunity to use a modular structure of the software, i.e. different multibody formalisms may be combined with different simulation programmes via standardized interfaces. For the DFG project the database RSYST was chosen using standard FORTRAN 77 and an object oriented multibody system datamodel was defined. The project included • research on the fundamentals of the method of multibody systems, • concepts for new formalisms of dynamical analysis, • development of efficient numerical algorithms and • realization of a powerful software package of multibody systems. These goals required an interdisciplinary cooperation between mathematics, compu ter science, mechanics, and control theory. ix X After a rigorous reviewing process the following research institutions participated in the project (under the responsibility of leading scientists): Technical University of Aachen (Prof. G. Sedlacek) Technical University of Darmstadt (Prof. P. Hagedorn) University of Duisburg M. Hiller) (Prof.

This book introduces the techniques needed to produce realistic simulations and animations of particle and rigid body systems. It focuses on both the theoretical and practical aspects of developing and implementing physically based dynamic simulation engines that can be used to generate convincing animations of physical events involving particles and rigid bodies. It can also be used to produce accurate simulations of mechanical systems, such as a robotic parts feeder. The book is intended for researchers in computer graphics, computer animation, computer-aided mechanical design and modeling software developers.

Mechanical engineering, an engineering discipline born of the needs of the industrial revolution, is once again asked to do its substantial share in the call for industrial renewal. The general call is urgent as we face profound issues of productivity and competitiveness that require engineering solu tions, among others. The Mechanical Engineering Series features graduate texts and research monographs intended to address the need for informa tion in contemporary areas of mechanical engineering. The series is conceived as a comprehensive one that will cover a broad range of concentrations important to mechanical engineering graduate edu cation and research. We are fortunate to have a distinguished roster of consulting editors, each an expert in one of the areas of concentration. The names of the consulting editors are listed on the front page of the volume. The areas of concentration are applied mechanics, biomechanics, computa tional mechanics, dynamic systems and control, energetics, mechanics of material, processing, thermal science, and tribology. Professor Leckie, the consulting editor for applied mechanics, and I are pleased to present this volume of the series: Kinematic and Dynamic Simulation of Multibody Systems: The Real-Time Challenge by Professors Garcia de Jal6n and Bayo. The selection of this volume underscores again the interest of the Mechanical Engineering Series to provide our readers with topical monographs as well as graduate texts. Austin Texas Frederick F. Ling v The first author dedicates this book to the memory of Prof F. Tegerizo (t 1988), who introduced him to kinematics.

Comprehensive, up-to-date and firmly rooted in practical experience, a key publication for all automotive engineers, dynamicists and students.

Dynamics of multibody systems is of great importance in the fields of robotics, biomechanics, spacecraft control, road and rail vehicle design, and dynamics of machinery. Many research problems have been solved and a considerable number of computer codes based on multibody formalisms is now available. With the present book it is intended to collect software systems for multibody system dynamics which are well established and have found acceptance in the users community. The Handbook will aid the reader in selecting the software system which is most appropriate to his needs. Altogether 17 research groups contributed to the Handbook. A compact summary of important capabilities of these software systems is presented in tabular form. All authors dealt with two typical test examples, a planar mechanism and a spatial robot. Thus, it is very easy to compare the results and to identify more clearly the advantages of one or the other formalism.

This textbook – a result of the author’s many years of research and teaching – brings together diverse concepts of the versatile tool of multibody dynamics, combining the efforts of many researchers in the field of mechanics.