Objektorientierte Modellierung mechatronischer Systeme am Beispiel geregelter Roboter M. Otter Fortschrittsherichte VDI, Reihe 20, Nr.147, VDI-Verlag Diisseldorf, 1995 ISBN 3-18-314720-3 (in German)

This book (aPhD thesis) starts with a short overview on modelling in various disciplines and the presenta- tion of DYMOLA, the simulator that serves as a basis for the developments in the next chapters. Furthermore, a roboter system is presented as an example for a system that has to be modelled with tools coming from different disciplines: the mechanical parts - with multi- body system tools; the electric motors and their control _ with electrical engineering tools; the controllers of the joints - with control engineering tools. In the fol- lowing chapters the author describes object-oriented (00) modelling techniques, starting with basic con- cepts and basic algorithms and also state-dependent structural variable systems. Then the 00 modelling of multi-body systems, of drives and of control systems follows. In each of these chapters the author gives a theoretical (mathematical/physical) background and also related case studies. Furthermore, he develops the corresponding tools in DYMOLA. These modelling techniques are finally applied to a model for a concrete robot system, with interesting experiments. The book concludes with a discussion of the presented methods and an outlook to the future. In addition, the reader can find several proofs and aspects connected with DAE systems, a description of DYMOLA and a summary of the developed class hierarchies.

This book gives a good documentation of the capa- bilities of 00 modelling techniques and of the features of DYMOLA. It is shown in an understandable way how to build up models of mechatronic systems. The book can be highly recommend.

.I. Plank, Dept. Simulation Techniques, TU Vienna, Email: jplank@argesim.tuwien,ac,at

Solid State Physics Simulations The Consortium of Upper-Level Physics Sotware John Wiley &Sons 1996 ISBN 0-471-54885-S

In the book series “The Consortium of Upper Level Physics Education”, edited by John Wiley & Sons, a while ago the title “Solid State Physics Simulation” was published. The name already indicates that this part of the series is mainly concerned with computer simula- tions of physical effects and properties relevant to solid state physics. The programs run in the DOS mode on any PC. This fact, however, can be regarded - as far as

user friendliness and graphics are concerned - as a minor drawback and cannot be considered as state-of- the-art. Nonetheless, the user interface is quite conven- ient and does its job, even if the appearance might seem a bit clumsy.

The book issued together with a diskette contains basically a chapter for each of the seven programs which cover several aspects of solid state physics (Pho- non Dispersion Curves and Density of States, Lattice Specific Heat of Solids, Electron States in a One-Di- mensional Lattice, Energy Bands, Gaps, and Eigen- functions in an Injinite Lattice, Free Motion of a Wave Packet in a One-Dimensional Luttice, Inhomogeneous Semiconductor Laboratory, LCAO Workbench). I would like to mention, however, that in my regard too much emphasis is put on energy bands and wave func- tions and some of the programs seem to cover too similar subjects. This fact is even more evident, if one takes into account the programs in the other part of the series entitled “Modern Physics”. Each chapter consist of three parts. In the first part the theoretical background of the physical phenomenon simulated in the program is described. What follows is a short description of the program and finally, several simulation examples are given. The treatment of the theory is well done and gives a good background. However, in my opinion at least, this section arises more expectations for the computer program than the actual features of the simulation can live up to. Performing the simulations the connection with the theory it is not always evident.

As an example I would like to mention two of the programs in more detail. In Electron States in a One- Dimensional Lattice we can observe the development of energy bands, as one progresses from single atoms to a simple solid. The influence of several parameters can be studied. For instance, the appearance of energy levels in forbidden zones as a result of defects can be visualized. By means of the LCAO Workbench we can obtain a first insight in the energy levels and physics of clusters.

In conclusion, the physics simulation course “The Consortium of Upper Level Physics Education: Solid State Physics Simulation” in spite of some justified critique proves to be a useful tool for undergraduate physics education in order to demonstrate several phe- nomena and quantities from solid state physics. A prior knowledge of the issues involved or a detailed study of the theory found in the book seems to be necessary before a useful “playing” with the simulations.

W. Husinsky, InstitutL Allgemeine Physik, TU Wien Email: wohuiap@iap. tuwien.ac.at

EUROSIM - Simulation News Europe - p35 - Number 19, March 1997