A fuzzy PID controller with nonlinear compensation term for mold level of continuous casting process

Abstract

The mold level is the key to stable continuous casting production process, and its fluctuation determines the quality of the slab. It is of great economic and scientific value to stabilize the mold level in numerous disturbances and complicated operating modes. To achieve high-precision and fast-response control of mold level control in engineering applications, a fuzzy PID controller with nonlinear compensation term is designed in this paper. By analyze the dynamic characteristics of the mold level, a fuzzy PID controller is designed. The parameters of fuzzy controller is optimized by using PSO algorithm, which achieves a better control effect in abnormal operating conditions. More importantly, a nonlinear compensation term is introduced to compensate the output of the fuzzy PID controller, thus further improving the anti-interference ability of the system. To verify the superiority of our method, a series of simulation studies are carried out. Finally, the method is applied to industrial sites. The running results show that, compared with the traditional control method, our method effectively improves the anti-interference ability under normal operating conditions and better suppresses the fluctuation of casting opening.