Ernst G. Schlechtendahl – författare

Principal authors: U. Kroszynski, B. Palstr9Sm 1.1 The evolution of concepts and specifications for CAD data exchange The CAD/CAM community has witnessed, during the last decade, the appearance of several specifications as well as proposals for standards which either attempt to cover wider areas or to be more reliable and stable than the others. With the rapid evolution of both hardware and software, the capabilities offered by CAD systems and CAD based application systems are far more advanced than they were only ten years ago, even when they are now based on micro-computers or personal comput­ ers. The situation with standards, however, is not and cannot be so. In order to be reliable and accepted by a wide community of both vendors and users, a standard has to be sta­ ble. This implies a life span of at least a decade. This also implies that the standard has to be general and flexible enough to accommodate present as well as expected future developments. 1.1.1 IGES The initial development of concepts for CAD data exchange is strongly influenced by the US Integrated Computer Aided Manufacturing (ICAM) programme, that dealt with the development of methods for data exchange. In September 1979, a subgroup was estab­ lished with participation of the National Bureau of Standards, the General Electric Com­ pany, and the Boeing Company. The result of this effort was the Initial Graphics Exchange Specification (IGES) that was published as a NBS report [61] in 1980.

2 e This book describes principles, methods and tools that are common to computer applications for design tasks. CAD is considered in this book as a discipline that provides the required know-how in computer hardware and software, in systems analysis and in engineering methodology for specifying, designing, implementing, introducing, and using computer based systems for design purposes. The first chapter gives an impression of the book as a whole, and following chapters deal with the history and the components of CAD, the process aspect of CAD, CAD architecture, graphical devices and systems, CAD engineering methods, CAD data transfer, and application examples. The flood of new developments in the field and the success of the first edition of this book have led the authors to prepare this completely revised, updated and extended second edition. Extensive new material is included on computer graphics, implementation methodology and CAD data transfer; the material on graphics standards is updated. The book is aimed primarily at engineers who design or install CAD systems. It is also intended for students who seek a broad fundamental background in CAD.