Study On Chaos Optimization-based Parameter Self-tuning Pid Control Strategy For Electro-Hydraulic Servo System

Since the twentieth century, especially with the development of automation technology and continuous improvement of the industrial automation systems, electro-hydraulic servo system has also got a booming development. Electro-hydraulic servo system is a typical nonlinear and uncertain system. Because of the uncertainty of the parameters and external load disturbance, it becomes more and more difficult for the conventional PID controller to meet its requirements. The controlling problem of uncertain-nonlinear system has got a breakthrough with the emergence of intelligent control. The intelligent PID controller, which comprising intelligent control and conventional PID control, not only has the advantage such as good dynamic quality, high reliability and so on, but also can be capable of self-learning, self-organization, self-adaptation and tune control parameters automatically according to the change of the control processing parameters. So it has important theoretical and practical engineering significance to have a study on the intelligent PID controller.Chaos is a random motion without any additional factors which itself has intrinsic randomness. Since the chaos has neither superposed nor overlap attractor, it can effectively avoid falling into local minima and therefore it can effectively solve control problems of nonlinear and uncertain system. In this paper we design a chaos-PID controller by applying the chaos optimization method into the conventional PID control and then apply it to control the electro-hydraulic servo system so as to improve the dynamic quality of the controlled system.Firstly, to explain thoroughly the basic theory and dynamical characteristics of chaotic motion and then apply it to the PID parameters tuning, in which way to devise a parameter tuning PID controllers based on chaos optimization.Secondly, to establish the mathematical model of the electro-hydraulic position servo system of the material testing machine and then to respectively simulate using conventional PID control method and PID control method based on chaos optimization so as to comparatively study the performance of the system.Finally, to design a computer control system of PID parameter tuning based on chaos optimization method in LabVIEW software development platform and then use it to carry out the real-time control experiment on the electro-hydraulic position servo system of the material testing machine.The result of simulation and experiment improves that PID parameter tuning based on chaos optimization method can improve the dynamic quality of the system and can get a satisfactory controlling results.