Application of an intelligent fuzzy PID in temperature control system

An intelligent fuzzy PID (IF-PID) control algorithm was proposed aiming at the characteristics of time-varying, nonlinearity and lag of temperature control system. The fuzzy control was used when the error was large and the fuzzy PID control with independent differentiation was used when the error was small by threshold-switch method. Then the simulation models were created in Simulink of Matlab for simulation comparison of PID control, fuzzy control and IF-PID control. Simulation results show IF-PID is better than the others in overshoot, settling time obviously and it has good adaptability and robustness. Thus it is very suitable for the control of nonlinear system with time-varying delay, which is an ideal control algorithm.