The Study And Application Of Differentiator And Differentiator Controller

This thesis discusses differential estimator and controller and their application. It is a part of project that intelligent estimator and controller and their application in the system adjust speed by changing frequency which is sponsored by developing fund of science and technology in university of Tianjin city.The estimating precision , ability of disturbance-rejection and the filtering characteristic of classical differentiator are discussed in the paper. We point out it's problem based on simulation by MATLAB. The structure of traditional PID as well as its advantage and disadvantage are discussed.At present, the PID controller and the intelligent PID controller is widely used in the controlling process of industry. PID control can realize system's dynamic expectation property through the differential of the error between input signal and output signal of the closed-loop system. It's control rule bases on the function of error and error's differential. But PID controller only concerns error's one order differential only, does not concern the second and high order of error's differential, thus the PID controller can't depict dynamical behavior perfectly.Usually the controlled plant is nonlinear high order uncertainty system. According to the viewpoint of inverting system, the controller also should concern with the input output signal and it's differential and higher order differential, therefore it is not enough the controller concerns signal and it's one order differential only.High order differentials feedback controller doesn't depend on the model of the system, its control objective is that the output of the system and its differential and high differentials approximate the given reference input, and its differential and high order differentials. Improve largely requirement of the control quality. Based on the idea, design high order differentiator (HOD) that is well able to extract differential and high order differentials of measured signals, the HOD has preferable ability for resisting high frequency interferential signal, and is provided with perfect precision, the proposed HOD has a few parameters and is easily adjusted. Furthermore, presents high order differentials feedback adaptive controller (HODFC) for unknown model nonlinear SISO systems with unknown disturbance, and gives the analysis of stability and robustness of the closed system. At the same time, some applications of differentiator are introduced in the paper.