Design and Simulation of Smith and Fuzzy Turning PID Controller

An improved Smith predictor is proposed.According to the shortcoming of traditional Smith prediction control relying on precise mathematic model and the difference between Smith predictor and controlled object,the Smith pure hysteresis compensation principle and Fuzzy adaptive turning PID parameter control integrated algorithm are adopted.The controller of traditional Smith prediction system is replaced by Fuzzy turning PID controller.And the method is adopted in the diameter controller of laser crystal growth system.Experiment results show that the method adopted is feasible,and the advantages of the Fuzzy PID controller and Smith predictor are combined and satisfactory control effects are gained for the laser crystal growth system with the nonlinear,great inertia,pure hysteresis and time -varied characteristics.