TVCAPP, tolerance verification in computer-aided process planning

An expert system approach to generate alternative process plans for mechanical parts with tolerance requirements is described. The expert system, TVCAPP, starts by extracting and verifying dimensional and geometrical tolerances for each machining surface. The selected groups of machines and tools are then verified by the machining parameters which are generated based on geometric dimensioning and tolerancing approach. The geometric tolerancing features such as the dimensional and shape variations of surfaces, straightness, circularity, cylindricity, and concentricity with a given datum, were considered in the design of the tolerance verification module. Application of the expert system to a mechanical part is illustrated.