Rapid conceptual design evaluation using a virtual product model

Abstract

This paper presents an architecture and test results for a computer-based system for assisting the conceptual phase of building design. The system uses 3D CAD to represent a graphic model of the design, and it uses AI symbolic models of the geometric forms, intended functions and computed and assigned behaviors of the design. The system uses A1 symbolic reasoning methods to analyze design behavior and compare predicted behavior with intended function. The Semantic Modeling Extension (SME) system incorporates a virtual product model: a small but extendible set of classes that define generic forms, functions and behaviors of facilities. After drawing a design using 3D CAD, a designer interactively creates interpretation objects as instances of the virtual product model. The interpretation objects express the meaning of the graphic representation with respect to a particular engineering issue, such as energy use or cost. The interpretation represents geometric and topological attributes of the features for use by automated design analysis tools. Interpretation objects unite support for graphically-oriented design thinking with support for automated symbolic reasoning. The paper includes an example building design scenario using the software prototype, illustrating how interpretation of the geometric model produces a symbolic model and supports multiple and changing analyses and evaluations during design. Students and practising engineers have tested the system in classes and workshops.