Application of Model-Free Adaptive Control in billet flash butt welding

In the process of billet flash butt welding of the ending welding rolling (EWR), the huge upset force served by dual loading hydraulic cylinder must respond with high-speed, and it demands the two cylinders move and load synchronously while the cylinders are sharing the even load. Furthermore, in the upset force loading system, there are nonlinear parts which are difficult to model accurately, time-varying parameters to hydraulic system, and force coupling arising from mechanical structure. Considering abovementioned challenges, we present our force control approach based on Model-Free Adaptive Control (MFAC) and element-based physical modeling. First, the element model of loading system is directly built upon AMESim, thus ensuring our model reflects the nonlinearity characteristics of hydraulic system and the feature of actuator mechanical coupling; second, MFAC is designed and based on it the force servo simulations research are done through joint platform provided by AMESim and Matlab. The results show that the difficulty of modeling the system is successfully solved by introducing of physical modeling tool of AMESim, the upset force servo can achieve sound performance based on MFAC, and hence, the feasibility of our approach is verified.