Modeling Technologies Of Manufacturing Process Resource And Application In Fixture Design Support System

Manufacturing process resource is an important enterprise information resource in product designing and manufacturing, and an indispensable part of information technology system in manufacturing industries. Facing individuation and diversification of user's demand and rapid change market competition, to realize the integration, share and optimization utilization of manufacturing process resource is a key factor in enhancing of enterprise rapid response ability. However, because of the diversity, complexity, experience, uncertainness etc.,. and other characteristics of manufacturing process resource, how to effectively generalize, arrange, formalize and digitize manufacturing process resource in dispersive enterprises so as to preserve them in explicit forms is one of the front studies in digitization of enterprises resource information system.The research work is. supported by the science and technology project of national tenth five-yesr plan (No.2001BA201A09) and the project of Sichuan province application foundation (No. 01CY051-29). By analyzing the demand of manufacturing process resource oriented collaborative process planning, according to problems existed in now manufacturing resource modeling, this research focuses upon the modeling" methods, technologies of integration and sharing, representation and optimization configuration of manufacturing resource oriented collaborative process planning, and application technologies of fixture design support system based on resource sharing platform. The main achievements and highlights of the dissertation are as follows:(1) Based on object-oriented modeling principle, by using structure, ability and state of manufacturing process resource as object, the basic structure, extraction method and abstract principia of the object are analyzed, and manufacturing process resource base including product database, equipment resource base, tooling resource base, process knowledge base and process planning database is built. The representation schema, description method, stratification management and storage method of resource base are discussed. Based on functional requirements of manufacturing process resource sharing platform, the key technology of manufacturing process resource sharing in cooperative process design is presented, including data diversion, retrieval mechanism, data exchange standards and interface technology.(2) Aiming at representation of feature level structure, classification and resource object relation of manufacturing process resource feature, adopting design ideas of object oriented technology, feature modeling technology, feature mapping technology and fuzzy theory, feature model of manufacturing process resource is built and used to feature mapping between part structures, machining method and manufacturing process resource. Feature set of manufacturing process resource described by process procedure feature in process planning is researched, and then a formalized definition is given. The method of process procedure resource feature retrieved from manufacturing process resource database, and the retrieval algorithms of feature parameter similarity matching resource feature to process procedure are put forward. The method is then used in matching manufacturing process resource feature to process procedure feature.(3) Based on systematical, consistent and comprehensive description of the concepts, objects, activities and relationships among resources sharing, the theory, the method and architecture of the resources sharing schema are studied. The sharing process model of manufacturing process resource is built which is composed of four modules including resource organization, resource retrieval, resource application and resource maintenance. Through the analysis of the main framework of resource matching, semantic model to the resource attribute, resource ability, and resource relation and process unit task is defined and then formalized expression is given. The matching algorithm of process unit task to resource, resource to task imput and resource to task output is designed.(4) According to selecting and decision-making problems of manufacturing resource in process planning, the evaluation model and the evaluating factor system of manufacturing process resource are constructed. The multi-scheme decision-making problem without determining weights for each evaluation indices are studied and evaluation values are given by using fuzzy linguistic term. An integrative evaluation approach is proposed to solve such problems, the fuzzy preference relation about each evaluation indices between schemes is worked out firstly, and then this problem is solved through determining compromise weight and participants with conflicting preference. At the same time, this research focuses upon solving algorithm of dominance degree function based on fuzzy numbers linguistic, and decision-making method for Multi-scheme based on preference relation.(5) Manufacturing resource information model and process resource information model relevant to fixture design process is built by adopting BOOCH method. These models mentioned above can provide enough information support for all activities in fixture design and manufacturing process. The fixture resource system including fixturing knowledge base, fixture calculation base and fixture drawing base are designed. The concept of Directed Process Feature Relationship Graph (DPFRG) is put forward. The isomorphs of DPFRG are defined. The fixture case base is constructed with DPFRG and process feature properties of parts. The algorithm to calculate the similarity for part with process feature properties and the fixture case retrieval algorithms based on Directed Process Feature Relationship Graph is presented.(6) Fixture graphics library including parameter fixture element base, fixture component base and fixture case base is built. By adopting the technology' based on knowledge representation and reasoning, the design methods of locating and clamping knowledge in fixturing design are researched. By using the theory of manufacturing process resource modeling and the technology of fixture design, a fixture design support system based on resource sharing platform which is composed of manufacturing process resource management, fixture resource management, graphics library management, fixturing design management and design calculation management is developed for verification of the architecture, key technologies and implementing methods in the platform.