From PID to Model-free Controller

Several PID methods and their problems are analyzed. Basic theory and design method of model-free controller are introduced. After comparing the effects of PID with model-free controller, it is shown that 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. It can control a nonlinear and strong-couple system stably but PID cannot.