The Query Method Research On Knowledge-Based System For Car-Body-in-white Product Line Process Planning

BIW (car-body in white) product line process planning is an important part of which determines the assembly vehicle manufacturing period. Currently, process layout and planning still depend on the amount of experience that people obtain. The planning concepts and methods are comparatively behind the times. To remove the bottleneck, the well-developed software technology can be used to develop the KBS (knowledge-based system) for BIW product line process planning. Based on this system, the planning can be promptly carried out by planner in the digital environment, thus shortening the period of that. To make planner availably choose the information, it is necessary for the system to be integrated with the query wizard which is one of the key factor improving the system performance. Therefore, this article stresses the research on query methods and theories, and defines how to use the relevant technology to develop the query wizard in detail.The theoretical research of this article should take the actual condition of process planning into consideration. Firstly, the query wizard demand and data aimed to query such as standard components, manufacturing resources, process information and welding point information have been analyzed. Secondly, query methods have been researched. When selecting the search mode, the advantage and disadvantage of blind search, heuristic search and inductive search have been compared before determining the last one as the route. When selecting the reasoning mode, forward reasoning and CBR (case-based reasoning) have been analyzed before the feasibility of the latter one is confirmed. Then the detailed technical plan is set forth according to the search and reasoning mode. Based on CBR, the query wizard foreground and background application and the integration of those ones have been developed with SQL Server2000 and VC++.net platform and several software techniques. Thirdly, combined with the practical assignment of planning, the query wizard functions of all kinds have been tested.The significance of this article is the achievement of combining the query methods with BIW product line process planning, and the new thought of managing the process planning information of KBS. When developing the wizard, theories are partially put into practice and the ability to find,dispose,store,use knowledge is well enhanced, thus improving the efficiency of process planning.The article finally expects the query methods research of the latter period, bringing forward the improvement of date storage,query confidence level,intellectualization and so on.