Study Of Case-Based Reasoning Modular Fixture CAD System

The high flexible fixture has been an imperatively accessorial means of modern manufacturing system, but there has not appeared very maturely commercial Computer-Aided Fixture Design software as yet. Modular fixture is developed on the base of the systemization, specification and standardization of the fixture. The application of the modular fixture can save the materials and develop time, reduce the cycle for development, it makes significant sense for the quality of the product.The emergence of the Computer-Aided Modular Fixture Design makes it possible to assemble the modular fixture virtually, and have a higher speed than assemble manually, also it can increase the productivity and decrease the labor intensity. Case-based reasoning (CBR) technology saves the former successful case and builds corresponding representative case database and mechanism of case. For the kindred product, the system can use for reference the former successful case. For these reason, it can improve the design efficiency. The research works have been done as follow:With Family Table, provided by Pro/Engineer, to explore the technique standard library. Firstly, establish the 3D character of standard parts in Pro/Engineer, set the standard parameter of standard parts, then input the parameter of standard parts of different types with the function of Family Table, establish the Family Table library of different parts. Construct the case warehouse of the modular fixture and special structure on the base of Microsoft Access.Based on the information model of modular fixture element and component, modular fixture object assembly model is established, modular fixture object assembly rule is proposed, modular fixture object assembly tactics according to hierarchy and effective assembly path are introduced, algorithm for rapidly creating assembly path is built up. Case based reasoning method for computer aided modular fixture design. Introduced the case-based reasoning principle and key technology; detailed describe example based modular fixture design process and the similarity calculation; focus on the case retrieval strategy and examples modification method.Study the method to construct the new fixture based on parametric fixture case assembly. Focus on the parametric fixture assembly, study the fixture assembly reconfiguration strategy which keep the assembly relation of old assembly, and design the reconfigure flow.