Adaptive backstepping control of hydraulic servo system with input saturation for rolling mill based on multi-model switching

For the problems of parameters change abruptly and input saturation of the rolling mill hydraulic servo systems, an adaptive backstepping control method based on multi-model switching is presented in this paper. Firstly, multiple models of the rolling mill hydraulic servo systems under different operating modes are established. Secondly, an auxiliary system is introduced to reduce the effects of input saturation, and the adaptive backstepping controllers are designed for all subsystem. With the help of common Lyapunov theory, the proposed method can guarantee stability of the multi-model switched system under arbitrary switching strategy. Finally, the simulation results demonstrate the effectiveness of the proposed control method.