Study On Cloud Model Parameter Self-tuning Pid Control Strategy For Electro-hydraulic Servo System

In recent years, due to the development of the military and aerospace technology,electro-hydraulic servo control technology is developing rapidly. Electro hydraulic servosystem is a typical nonlinear uncertain system, with characteristics of time-varyingparameters, external load disturbance and other factors, so using conventional PIDcontroller is difficult to meet the control requirements. The development of intelligentcontrol, in order to solve control problem of complicated nonlinear uncertain system,found the new method, combining intelligent control with conventional PID control,Structure of the intelligent PID controller, both intelligent control the ability ofself-learning, self-organizing, adaptive, can according to the change of parameters incontrol process, automatically setting control parameters, and PID control advantages ofgood dynamic quality and high reliability, so the research on intelligent PID controller isvery important to both theoretical research and engineering application.The cloud model is a method of uncertainty, the cloud model is applied to theintelligent control, can not depend on the accurate mathematics model of controlled object,effectively solve control problem of nonlinear, uncertain system. In this paper, the methodof cloud model is combined with conventional PID control, constitute a cloud model PIDintelligent controller, and applied to the control of electro-hydraulic servo system, in orderto improve dynamic performance of the controlled system.Firstly, expounds the basic theory of cloud model, Including the basic concept ofcloud model and cloud model generator, etc., on the basis of a study of rule reasoningprinciples of cloud model. The rule reasoning of cloud model is applied to the PID controlparameters tuning, designed a parameter self-tuning PID controller based on cloud model.The controller to adjust PID control parameters in engineering experience into control rulebase, and then according to the actual response of the control system, using cloud rulereasoning, tuning PID control parameters online.Secondly, to establish the mathematical model of material testing machine electricalhydraulic position servo system, and used to construct the simulation model of the MATLAB Simulink software package, Respectively using cloud model parametersself-tuning PID control strategy and the conventional PID control strategy, For comparingthe performance of the system simulation.Finally, based on LabVIEW software platform, design a computer control system ofthe parameters self tuning controller based on cloud model. Application of the system,carry on the computer real-time control experiment of material testing machine electricalhydraulic position servo system.The simulation and experimental results verify the cloud model parameter self-tuningPID control can improve the dynamic quality of the system, obtain satisfactory controleffect.