Model reference fuzzy adaptive PID control and its applications in typical industrial processes

To improve the dynamic response, regulation precision and robustness of the closed-loop system, a novel two degree of freedom control method called model reference fuzzy adaptive PID (MRFA-PID) control is proposed for industrial processes. The proposed control law consists of two parts, PID controller and fuzzy logic controller. The PID controller, which is designed for the nominal plant, guarantees the basic requirement on stability and product quality. The fuzzy logic controller, as an extra degree of freedom, improves the system dynamic performance, regulation precision, and robustness to the uncertainty of the system. The effectiveness of MRFA-PID control is illustrated by its applications in some typical industrial processes. Since the proposed method need not identify the uncertain parameters of the plant, it has a very good real-time performance, and is easy to be implemented on-line.