Self-Tuning Of PID Controllers

Because of its simple theory. good robustness and being early mer-chandised, PID controllers are widely used by control engineers. The majority of the controllers used in industry are of the PID type. But on the other side . it has a important problem—parameter tuning.Tuing PID controllers manully both takes considerable time and is not benificial to economy. It is natural that self—tuning became the popular task of process control. Experts have done lots of work and made some achivements at this. Based upon analysing the existing methods, the new method that could automatically tune PID controllers was developed.The most important part of the new method is process identification. The author acquired the model of the process on line by using the step response and enen rectangle wave response of the process. Then. based upon the existing documents. this paper revised and set out the self—tuning formulae of single—loop and cascade control system. At last, the result of simulation tests of several typical control system was set out to verify the adaptability of the method.