Fuzzy Supervisory Control with Fuzzy-PID Controller and Its Application to Petroleum Plants

This chapter presents a new practical control system that can apply conventional PID controllers to nonlinear field by using fuzzy reasoning. The proposed system is a hierarchical one consisting of two components: (a) a Fuzzy-PID controller, and (b) a supervisor for setting the control target of this controller. The fuzzy controller in the Fuzzy-PID controller compensates the output error of the conventional PID controller. The supervisor calculates the control target by fuzzy reasoning. This hierarchical control system is applied to the temperature control in a petroleum plant. The parameters in fuzzy controller are tuned on-line in the actual plant and the system can control the temperature effectively in the transient state, such as feed property changing or operation mode changing, as well as in the steady state