Research On Expert System Of Resistance Spot Welding Of Stainless Steel

The manufacture industry including welding develops towards advanced technology based on information while it is rapidly developed of science and technology in the world. Meantime, as for a important method,, the expert system technology will lead welding technology into informationization, automatization and intelligence. On the other hand, the expert system application can be more competitive for enterprises in market,improve the scientific research ability and production efficiency, resource conservation and production costs also can be reduced.A resistance spot welding process in which fusion is produced by the heat obtained from the resistance to the flow of electric current through the workpieces held together under pressure by electrodes. As for one of the fast,affordable important methods, it applies to producing the sheet of stamping and rolling which orders the lap joint non-gas tightness and less than 3mm.It is a preliminary part in welding production to regulate welding procedure and specification papers. A good welding procedure regulation can save the fund of production enterprises, reduce the technical preparation cycle and be more competition. Meanwhile to reserve the welding procedure regulation experience that comes from experts also make a great influence to the enterprises. The essence of expert system includes its expert knowledge, and the theory of knowledge application comes from knowledge indication and inference means. The system design bases on knowledge vault and inference mechanism, namely"knowledge library + inference mechanism = expert system", compare to the traditional software structure which is"data + algorithm = programme", as a knowledge ware, the expert system have many superior aspects and advantages in despite of its various editions and different structures.Above all, this paper had a main research on the functional model building of spot welding procedure and system structure design after the system function analysis. First, adequate knowledge in welding field was acquired and summed up, then selected to indication. In accordance with the inference mechanism of expert system, inference direction,searching strategy,conflict resolution strategy,methods of uncertainty inference. Second, data base design of welding information. As a direct form of expert system, the database which provides knowledge resource consists of base metal library,criteria library,standard library,process library and so on. Third, combined with the last two steps, model analysis was made and the final structure form was accomplished. Last, expert system test and the program installation.Applied with the software engineering method,modularized program and the model design of incremental environment, the system separate the control inference mechanism from information data as a knowledge source which can be managed and maintained by both developers and users with database control system, especially for users allowed to modify and expand the database. The inference mechanism control design of the system which is multilevel model, is convenient with the inference of system controlling and program testing,updating.Expert system of spot welding, which has visual windows, was developed by Visual Basic 6.0 software and SQL Server 2000 database. Visual Basic software has two special benefits: one is its integrated development environment; the other is its separation application programs from machine language, so it can be easily used to design,test and compile that programmers can be concentrating to the solution of actual problems instead of considering the details of windows application programs. The key point of the paper is software design of ES and record writing of the expert knowledge, and put an emphasis on solution of procedure regulation scheme under the plant circumstance.