Abstract: Thickness precision is an important index of measuring the products quality of a plate and strip mill. The high accuracy of strip thickness is needed to be realized through the thickness automatic control (AGC) system. In order to improve the thickness accuracy of the finished strip,fuzzy control,feedback mechanism of biological immune system and traditional PID control are combined in this paper to construct a fuzzy immune PID controller for strip thickness control system,using immune algorithm and fuzzy logic to adjust PID parameters on-line. Simulation results show that the fuzzy immune PID controller were better than thickness controller system based on conventional PID controller in response speed,overshoot,stability and robustness. It can improve the precision of the export thickness remarkably.

Key words: thickness control, fuzzy immune, cold rolling mill