The application of the phase plane in the tuning method for fuzzy PID

As a simple and practical nonlinear controlling strategy, the fuzzy PID controller still lacks of a standardized tuning method at present, which causing the performance can be guaranteed. The paper analyses the method for designing the fuzzy PID rule library on the phase plane and presents the general steps for development. The rule library makes flexible changes to describe the nonlinear characteristics of the object accurately according to the corresponding dynamic trait on the phase plane. Simulation results prove the better performance with the introduced method, which plays a strongly instructional and practical role in the tuning of the fuzzy PID controlling.