Dryer surface temperature control system based on improved self-adaptive fuzzy Smith prediction controller

In bank-note paper making process, the paper moisture is controlled mainly by regulating the steam traffic of dryers to change the surface temperature of dryers. The heat transfer process of drying bank-note paper is very complicated, and the process has serious nonlinearity, parameters drift, lag and inertia characteristic etc, so the accurate mathematical model of the process can not be acquired. A self-adaptive fuzzy Smith prediction control system for the dryer surface temperature is introduced in this paper. According to the deviation of the dryer surface temperature, some control strategies are adopted in the system. The bang-bang control method is used to reduce the rising time and regulation time of the system; for improving the adapting capability and control precision, a self-adjusted fuzzy-PID controller is designed; in main feedback loop, the first-order inertia element is used to filter the history deviation, which can improve the Smith prediction controller when the model is mismatch. The results show that the control system works well, and also possesses better robustness and higher precision