PML - PRODUCT MODELING LANGUAGE

This paper presents the development of a design modelling language called Product Modelling Language based on analysis of CAD systems, modelling, and feature-based modelling. The language is a unique representation of product, solid and features, and an effective communication method for linking design and various manufacturing activities. The language consist of five levels: product level, unit level, part level, form-feature level, and feature-boundary level, each providing particular information. The product level includes information regarding the whole product such as product name, size, weight, specifications, directly assembled parts and sub-assemblies. At the unit level, information such as unit name, specifications, directly assembled parts and sub-assemblies is provided. The part level concerns information for the entire component such as part name, classification code, heat-treatment requirements, material type, and all solid primitives which form the part in a chosen solid modeller. At the form-feature level, information is required by the chosen solid modeller such as CSG (constructive solid geometry) primitives, their dimensions and locations in a given coordinate system. The feature-boundary level is designed associated with the boundary representation (B-rep). At this level, the detailed primitives information is provided such as dimensions, locations, tolerances, relations, surface finish and the like. The language syntax, semantics and vocabulary have been defined by taking into consideration human designer, compatibility with engineering terminology, computer implementation and future expansions. The language processing system consists of a number of lexical analyzers, a parser and three translators which are used for solid modelling, cellular manufacturing planning and inspection planning. By using the language, solid model, feature-based model and product model and manufacturing applications have been integrated. An example is included to illustrate the language and its integration.