The Study Of The Car Body Quality Monitoring And Control System For RSW Joint

RSW is the main assembly connection means in car body manufacturing process. Spotwelding process is susceptible to variety of factors, such as material properties, surfaceconditions, process parameters, the network voltage fluctuations etc. It caused by theinstability of the welding process and lead to the defects of solder joints easily. In order toensure the quality of the body solder, most enterprises used quality assurance system, itcontained ensure welding conditions before welding-welding process feedback control-sampling after welding, but it can not ascertain the quality of each solder joint. This paperproposes a quality assurance model. A quality monitoring and management software system isdeveloped. It can real-time monitoring the welding process, obtaining quality information,realizing quality evaluation and management of each joint.There is a certain relationship between the welding parameters and the joint quality, Acombination of the actual body welding process and the basic principles of RSW analysis theimpact of different welding parameters on the joint quality. According to the requirements ofreal-time control of the welding process, the platform of real-time computer monitoringhardware is built. On the basis of obtaining the digital signal, the framework of the jointquality control system based on data-driven is put forward.A new quality guarantee mode is put forward to monitor each joint in RSW process forflexible car assembling line. The quality monitoring and management system is developed forin auto car assembling line. Firstly, through software engineering method, after the analysis ofthe system demands, the UML modeling tool are used to set up the system model of the needs,such as example-chart, state-chart and activity-chart etc, and the operation mechanism of thesystem model is analyzed. Secondly, the function structure and the flow chart of the functionanalysis is designed, and the data flow graph analysis the information flow between eachmodule. Thirdly, According to the database design process, the needs analysis, ER diagram,the physical and logic model is designed. Fourth, information monitoring, fault diagnosisquality evaluation and other major module carried on the detailed design. On the basis, thesome branch modules, such as information monitoring, quality evaluation, report generationand information management is realized by means of object-oriented programming languageVB6.0.Basis on the system of monitoring and management, the PLS-SVM data mining modelsis establish, it is key to achieve a solder joint quality evaluation. Firstly, the dynamicmonitoring data is extracted from the database, feature values is extracted, and data market isestablished. Secondly, the prediction model that the PLS-SVM established for the quality jointto predicted and judged the joint shear strength. Finally, the results of the model that solderjoint quality prediction is analysis and evaluate. Practical test result is shown that, the system can accomplish quality informationmonitoring, fault diagnosis, quality evaluation and management function of each joint. It is alow cost, easy and convenient quality control method.