Design And Analysis Of Model-free Controller For A Class Of Nonlinear System

At present, the controllers used in industrial process control are mostly classical PID which were developed in the 1940s. The basic idea of designing this kind of controllers is based on linear system construction. Despite of ensuring stability in many applied systems, this controller cannot overcome nonlinear influence and disturb effect. Modern control theory has been fast developed in recent years, but many mathematical models of controlled objects cannot be given suitably. Therefore, it is of great theoretical significance and applicable value to find out control methods which are supposed to have low demand to models and are with better comprehensive control effect.Model-free controller is a new kind of controller, which combines modern control theories with classical PID. The method of designing model-free controller is only using inputs and outputs, which is independent of the mathematical model of controlled objects. Model-free controller is absolutely different from PID and its designing in linear pattern. It is a new controller in which an adaptive pattern and the unity of modeling and controlling are used.This paper introduces the progress of theory and application of model-free controller. The issues of model-free controller which is based on universal model are particular represented. Then we analysis the convergence and rationality of model-free controller. To further enhance the performance of model-free controller, we can get a new algorithm of model-free controller by universal model improved. In the end, simulation results show that the new control algorithm is obviously better on the ability of traceability and adaptability.