Research On Control Algorithm Of Pure Lag System

A series of advanced PID control methods specific to pure lag systems are studied in this paper. Simulations of conventional PID control methods and intelligent PID control methods are given by taking advantage of Matlab. The results show that conventional PID control methods perform well in pure lag system if proper control parameters are set under the condition of permanent system parameters and environment. Considering the disadvantages of conventional PID control, the fuzzy adaptive nonlinear PID control algorithm and improved RBF neural network PID control algorithm are presented in this paper. PID control parameters are adjusted adaptively according to the parameters of the object. The adaptability, robusness and easy operation are improved significantly compare to the conventional PID control methods.The main research methods are as follows:Several improved PID control methods are discussed and a number of problems of pure lag systems are analyzed by researching the advantages and disadvantages of conventional PID control methods.The mechanism of fuzzy control is analyzed. The idea of adjusting nonlinear PID parameters is put in and a fuzzy adaptive nonlinear PID control algorithm is raised based on the combination with conventional PID control algorithm. The fuzzy rules are designed dynamicly via the non-linear characters by experience to adjust the PID control parameters adaptively.PID control algorithm which based on BPNN tuning is studied. The algorithm can adjust the PID control parameters adaptively according to the changing of delay system parameters, and have a great capacity of anti-interference. Improvements of the neural network learning algorithm are proposed by the research of PID control based on RBF neural network. And the Smith controller based on RBFNN-PID is applied to the pure lag system control, achieved the rapidity of system response and adaptability of control parameters.