Temperature control of a plastic extrusion barrel using PID fuzzy controllers

In this paper, a new PID fuzzy scheme is proposed to control the temperature of a plastic extrusion barrel. This fuzzy controller is based on the proportional-integral derivative fuzzy control scheme with if-then rules and triangular membership functions. For a traditional PID controller, the output is a linear combination of the error of the system, the derivative of the error, and the integral of the error. On the other hand, a conventional fuzzy controller has a nonlinear function of the error of the system and the derivative of the error as output. Since a nonlinear controller can usually control a nonlinear system more efficiently, thus fuzzy controllers often provide better performances than PID controllers in terms of shorter rise time and smaller overshoot. However, the traditional fuzzy controller cannot improve its steady-state performance for time-varying systems. To avoid this drawback, the PID fuzzy controller is developed. The design of this controller is briefly described. Then the experiment results are demonstrated. It is shown that the PID fuzzy control algorithm can meet the requirement of this temperature control project