Paul Veerkamp

Intelligent CAD Systems III

Designing often involves rather complex processes of reasoning. For building knowledge-based systems for designing, a detailed logical analysis of these processes is inevitable. This paper aims to present a logical framework for describing the steps in a design process as logical inferences. To represent the various kinds of reasoning involved, this framework uses reasoning about viewpoints and reasoning about partial models. These are particular kinds of meta-level reasoning. The logical framework, which is presented in this paper, offers a basis for a formal specification of knowledge-based systems for design.

Design process representation in ADDL

This paper presents the use of ADDL (Artifact and Design Description Language) for design process representation in an intelligent CAD system. ADDL is a special purpose programming language which conceived at the Centre for Mathematics and Computer Science (CWI). It is now being further developed both at the University of Tokyo and at CWI. ADDL is designed for implementing systems which assist a designer in performing a design task. It allows dynamic design object descriptions and a flexible design process representation. In this paper we briefly introduce design object representation in ADDL and elaborate on design process representation. In particular, we pay attention to the multi-world mechanism and the scenario interpreter. In the last section the actual implementation of ADDL on top of Smalltalk-80† is discussed.

Qualitative reasoning about design objects

Abstract This paper presents an intelligent design system which interactively assists a designer during the design process. The system is based on a general design model by which design is viewed as a stepwise refinement process. During this process a model of the design object is gradually refined from a rough abstract model to an exact description meeting the desired specifications. This model is called a meta-model since it is used as a central model from which aspect models are derived. For the meta-model description we use a qualitative model which describes the design object in terms of function and behavior. The system is a so called empty shell since it is only a framework on which an intelligent CAD system can be built. As an example we show an intelligent CAD system for the key design of a technical device in order to visualize the phenomenon of aquaplaning.