The Research And Application Of PID Parameters Self-tuning

Because of its simple structure, adaptability, and no dependence on the precise model of the controlled object, PID control method becomes the most widely used control method. However, the difficult parameter tuning makes it difficult used in the dynamic, nonlinear and uncertain systems.The thesis will research the PID parameter tuning control theory, and analyze the model-identification-based PID parameter auto-tuning method and rule-based PID parameter auto-tuning method. And then the thesis research and reference several intelligent PID controller parameter auto-tuning methods and analyze a PID parameter tuning method based on relay feedback identification and step response pattern recognition. This method combines the advantages of the model-identification-based method, the rule-based method and the fuzzy control method. This PID controller is used in motor control. The thesis will analyze of relay feedback identification method, improve it with the fuzzy PID control method and the pattern recognition algorithms based on the actual application, and propose the algorithm according to the improvement. After that we will test the method under different speeds and different loads, and compare the results between manual tuning method and the new method just improved.Finally, the method is tested in practical industrial applications. Experimental results show that this method has preferable control performance, stability and strong practicability.