INTERACTIVE SURFACE MODELING, AN IMPLEMENTATION OF AN EXPERT-SYSTEM FOR SPECIFICATION OF SURFACE-ROUGHNESS AND TOPOGRAPHY

Making roughness a useful tool for obtaining optimally functional surf aces demands a high quality foundation for surface specifications. Err oneous specifications in many cases lead to costly production and perh aps nonfunctional surfaces. The Interactive Surface Modelling system, ISM, presented in this paper, addresses those problems with an approac h where functional demands control the route from specification of par ameters through manufacturing preparation to measurement of the machin ed surface. Here, the operator, be it the designer, the production eng ineer, or the quality control engineer, can iteractively reason with t he system to reach a suitable specification with the aid of integrated software in a PC-Windows environment controlled by an expert system s oftware. The representation of the surface's 3D geometry then is a nat ural component. The access to depiction and literature references and standards is implemented together with the ability to serve the user w ith graphic feedback by generating synthetic surfaces from the specifi cation made. The described features have been implemented in a prototy pe developed in cooperation between Volvo and Chalmers on two function al surfaces: cylinder liners and synthetic leather for the automotive industry. Problems with specifying correct roughness and topography ac tually have emerged when changes have been made of material or manufac turing process for an old and proven product. This has shown that know ledge is missing or incomplete about proper intervals for roughness pa rameter values for definition of the relationship between a surface's function and its parameters. The result is misunderstandings and error s. By letting ISM be a base for continuous updating and modification o f knowledge, opportunities will be created for increased quality of su rface roughness specifications through this systematic approach to the complex, expanding field of Surface Roughness and Surface Topography.