Research On Control Technology Of Spot Welding Based On ANN And FLC

Resistance spot welding has the advantages of high production efficiency, simple operation and easy to realize automation. It is widely used in the fields of aerospace, automobile manufacturing and other industries. However, the resistance spot welding is a complex and dynamic process with time- varying, highly non- linear and multi-parameter coupling which is difficult to use accurate mathematical model to describe the relationship between welding parameters and welding quality. Therefore, how to establish the model of resistance spot welding process parameters and welding quality and effective control of the optimized welding parameters is the main research direction in this research field. This paper mainly studied the resistance spot welding process parameters optimization and welding current fuzzy logic control(FLC).Firstly,this paper analyzed the welding process of 0.8 mm thick 08 AL steel plate.Study the influence of welding process parameters on welding quality and the model between welding process parameters and welding quality was established with artificial neural network(ANN). The three main process parameters(welding time, welding current and electrode pressure) optimal matching was obtained which optimized the model used logistic mapping particles swarm optimization algorithm(LPSO) to improve the global searching ability.Secondly, the welding current control system approximation mathematical model was seted up according to the working principle of the medium frequency inverter spot welding machine. At the same time, the variable universe fuzzy PID control theory was introduced into the welding current control system and designed the welding current variable universe fuzzy PID control system which can solve the problem of welding current control system with no precise mathematical model. The simulation result showed that the system has high control performance which can restrain the influence of various factors on the welding current in the welding process effectively and realized the constant process control of welding current finally.