The reasons why the methodology and techniques underlying CAD systems cannot be used as the basis for engineering design support systems required to integrate computer-based support of the engineering design process are given. An argument is put forward that a combination of artificial intelligence techniques and geometric modelling techniques can meet these requirements.

AI-based versus geometry-based design or Why design cannot be supported by geometry alone

Conceptual design is a process of converting design requirements into an acceptable design solution. An object-oriented system for conceptual design is presented. The process of component synthesis is guided by production rules. An object-oriented programming paradigm is chosen since it simulates the designer's way of thinking during conceptual design. The system is implemented in Smalltalk-80 programming language and environment. Besides providing all the characteristics of an object-oriented language, Smalltalk-80 allows for development of highly user-friendly interfaces. The design synthesis process is presented using a graphical and textual description.

Intelligent design synthesis. An object-oriented approach

IDABES: An expert system for the preliminary stages of conceptual design of building energy systems

A knowledge-based system is presented that has been developed to be used as an advisor in the preliminary design stage of HVAC systems. It enables designers to configure and size HVAC equipment for different climatic conditions, in terms of building type, indoor requirements, outdoor and indoor air pollution. A new approach has been used in building the system, using a modified knowledge engineering methodology and a menu-driven front-end to a full frame-based system.

Select-HVAC: knowledge-based system as an advisor to configure HVAC systems

This thesis explores the architectural requirements of engineering design support systems based on knowledge based systems technology. The exploration is based on an understanding of the nature of designing as a professional activity and on the extent to which designers' competence can be modelled. Attention is focused on certain salient aspects of designers' competent behaviour. The theoretical study leads to the specification of requirements to be satisfied by a knowledge based system which will support designers in their professional setting and to the proposal of some knowledge based system components which will meet the requirements identified. The theoretical aspect of the thesis is complemented by a case study based on a designer of high voltage electricity distribution networks. The case study illustrates the theoretical component of the thesis and the methodological basis for the work. The practical realizability of the components of the knowledge based systems architecture proposed are demonstrated using the results of the analysis of the knowledge elicited in the case study without prejudicing the general applicability of the ideas. An object-oriented knowledge engineering software development environment is used to demonstrate how some components of the design situation represented can be implemented.

Supporting engineering design using knowledge based systems technology with a case study in electricity distribution network design

This paper deals with knowledge representation of the conceptual design process for Building Energy Systems. The design problem is one of a set of problems where the ob jective is the design of a system that performs a certain function by selection and configuration of components whose characteristics and interrelationships are fixed and known. Domain, Constraint, Design, Analysis and Developing Solution knowledge are discussed in relation to the above problem. The need for heuristic design knowledge augmented by non-heuristic numerical knowledge is identified. Abstraction of knowledge into a modular and hierarchical form leads to efficient search for a design solution. This paper outlines the framework for a longer-term development of an expert system for conceptual design of Building Energy Systems.

James G. Doheny

Papers

Knowledge Representation in the Conceptual Design Process for Building Energy Systems