Application of Modified Control Strategies for Temperature Control Process of Conditioning Cylinder with Large Delay-Time

Systems with a ratio of delay-time to time constant greater than 1 are often difficult to be controlled, especially the robustness would be severely deteriorated. First, a simplified predictive PI controller is proposed, which utilizes predictive PI algorithm to tune the parameters of PID controller. Then, a pseudo-predictive PI controller is designed based on the simplified predictive PI controller. This controller utilizes the heating effect of the conditioning cylinder on the tobacco and combines the characteristics of the combined integral and predictive PI. Finally, the two control strategies are respectively applied to the first order plus delay time model, and the simulation results show that both control strategies have good properties of dynamic response, anti-interference, and no overshoot, when compared to commonly used control strategies, such as fuzzy PID. Most importantly, the robustness of both control strategies is excellent.