Reaserch On Design And Simulation Of Intelligent Adaptive PID Controllers

The PID controller since its inception has been the most widely used controller.However, PID controller has good control effects only when the PID controller hassuitable control parameters. As the controlled objects become more and morecomplex, some problems emerges, such as controlled objects difficult to model,inaccurate models and strong nonlinear controlled objects and so on, which makethe traditional PID controller parameter tuning method applicability get worse andintelligent PID controllers (mainly the PID controller parameter-tuning methodsbased on artificial intelligence technology) and new type PID controllers become theresearch hotspot.Modern PID controllers can be basically divided into two kinds as the PIDcontroller parameter-tuning methods.The first is based on the human’s controlexperience and the second is based on performance indicators. To a certain extent,these two methods get rid of the shackles of the plant model, but algorithms arerelatively complex, large amount of computing and badly real-time. Thecomputation of new type PID controllers is relatively small, basically free of theshackles of the object model, but new type PID controllers not only possess manyparameters but also the structure is relatively complex. Combine both advantages,the purpose of this paper is to design intelligent adaptive PID controllers, that is,without identification of an accurate model for the objects, the controllersautomatically adjust the parameters of the controllers in accordance with theinformation of the control system itself to achieve better control effect.This paper studies the common PID controller parameter-tuning methods, anduses these methods to simulate and analyze the simulation results. Considering theidea of the analytical description of the fuzzy PID controller and the variation trendsof PID controllers’ parameters in the process of system response, by a large numberof simulation and analysis, an intelligent self-adaptive PD controller and anintelligent self-adaptive PID controller are devised. Then these two controllers areadopted to control second-order controlled objects and servo objects, and thesimulation results show that these two controllers own better control performance.Finally, a new intelligent error weight factor are created to control nonlinear objects,which is use to simulate five different types of nonlinear systems. The simulationresults prove the effectiveness of the new intelligent error weight factor.