Research on Knowledge-based Intellectualized CAD System of Automobile Body Welding Jig

摘要

According to the modularization, standardization and other characteristics of automobile body welding jig,based on design experience, the analysis and summary of jig structures, research on knowledge-based intellectualized CAD system of automobile welding jig is carried out on the CAD software platform of NX adopting the method of object-oriented knowledge representation.The model of knowledge-based intellectualized CAD system is established firstly. And then the concept of outer process repository and inner design repository which include design repository of rule, module repository and case repository is put forward. Outer process repository is the knowledge representation of automobile body processes, welding jig design process sheet and design standards. Among inner repositories, the repository of design rule is the knowledge representation of design methods of welding jig and design experience. The repository of design module is the knowledge representation of typical module structure unit. The repository of design case is the knowledge representation of typical single positioning and clamping unit. In addition,the three-dimensional parameterized part graphic database is constructed. Mixed reasoning machine based on rule and case reasoning is realized. As a result, the knowledge-based intellectualized CAD system of automobile welding jig is accomplished. The initial intellectualized design of automobile welding jigs of the single work station can be completed using the system.