The Research Of Fuzzy Smith Intelligent Control Method And Its Realization Based On MCU

In the complicated industry controlled process, the controlled objects usually own the time delay, nonlinear, time-change characteristic and exist the category of interferences. So,if the traditional PID control method is only used, the static and dynamic output capability is not very satisfy ing. The fuzzy control as a branch of intelligence control field could be good at controlling those complicated,nonlinear systems with the characteristic of the parameter drift, the inaccurate model and time delay because the essence of fuzzy control is nonlinear control and adaptive control. Fuzzy control makes the systems more stable and more robust.Temperature box is a typical system which has pure lag, large inertia and time-change characteristic. Based on the theory of fuzzy control,this paper mainly studys fuzzy PID control which combine the fuzzy controller with PID controller to a new type of controller. Fuzzy PID of self-adjusting parameters is applied to the temperature control system of temperature box.Allowing for the system's peculiarity ,this paper discuss the self-adjusting rule of PID parameters,and design the fuzzy controller. Simulation results have shown that fuzzy control has very good control effect and robustness because it has the sensitivity and flexibility of fuzzy control and high precision of PID control.Smith predictor possessing one-order inertia tache is proposed for the large time-delay processe. The fuzzy control is applied to the Smith predictor,which make it adjust its parameter with the change of the object.Then,this paper propose the fuzzy Smith intellident control method which combines the fuzzy PID control with the fuzzy adaptive Smith predictor. By simulating when the object parameters is changed , regulation rules about parameters of inertia are obtained ,and a self-adjusting organ to adjust inertia tache parameter on real time is designed and realized based on these rules. Simulation results have shown that the method can improve the qualities of control and enhance the robustness and stability of the temperature control system.At last this paper study the realization of fuzzy Smith intelligent control method through a MCU(Micro Controller Unit).The hardware and software of the temperature control system based on a MCU are introduced in this paper.