Fuzzy Sliding Mode Control For Uncertain Time-Delay Furnace Temperature Systems

Because the control of temperature accuracy is required higher and higher in industry, the requirements of the control method for the stability, control accuracy and adaptability is increasingly high.the traditional method of control has not already met the need. Based on the present methods, researchers develop some new means. With the developing of intelligent control theory, more advanced methods which are on the basis of traditional closed loop PID, such as neural networks control, fuzzy control, adaptive control and combined approach of these methods, are used for improving the temperature control. Especially for the complex object, intelligent control is better than traditional ways.Because the controlled object becomes slow, large inertia and large hysteresis characteristics, we can not easy to establish accurate mathematical model of a furnace. Design of variable structure controller to weak the influence of the accused and the degree of complexity of the object outside interference system. System fast reaches a steady state and maintain the steady state of motion and then design of adaptive control to ensure that the system is robust in the external parameters of external interference and uncertainties.To further improve the stability control system and reduce sliding mode controller output chattering, we use the dynamic sliding mode controller and add adaptive fuzzy control to adjust the size of the sliding mode controller gain. Get the system smoother sliding surface and the control output. The controller has better control performance through simulation program.