Research On The Fuzzy PID Control Of Hydraulic System Of The Reloading Fine Blanking Machine

Fine blanking press is the special equipment to realize fine blanking process,the rapid cylinder system is a typical hydraulic servo system,the performance of the hydraulic servo system directly affects the stable operation of the system and the quality of blanking parts.With the development of the stamping parts toward the thick,large,complex shape and so on,the requirement of control accuracy,response speed and the degree of fine blanking automation of hydraulic system increasing.Therefore,it is an urgent problem to study the control strategy which is suitable for hydraulic servo system of fine blanking press.There are time varying parameters,nonlinear factors and load coupling in the hydraulic servo system of the hydraulic cylinder of the fine blanking press.The traditional PID control is difficult to obtain ideal control performance.Based on the hydraulic servo system of the quick cylinder of the 1200T hydraulic fine blanking press,which is producted by Huang Shi Hua Li Metal Forging machine tool co.LTD,as the research object,target for optimum control performance.The fuzzy PID control of the hydraulic servo system of the rapid cylinder is designed,and the following works are done:Firstly,the working principle and control characteristics of the fast cylinder are analyzed,and the mathematical model of hydraulic cylinder servo system is established by hydrodynamics and classical control theory,the stability and dynamic performance of the system are analyzed.Then,established fast cylinder hydraulic model based on AMESim.Reveals the factors that affect the system tracking error and stability.The PID control strategy is designed,optimizedK_p?K_i?K_d base on genetic algorithm,to get the optimal value.Combined with the application of intelligent control theory,a fuzzy PID control strategy is designed.In this paper,the fuzzy PID controller model is established in MATLAB/Simulink.Through the joint simulation interface technology,the hydraulic model is imported into Simulink to realize the joint simulation.The genetic algorithm is used to optimize the parameters of membership function,and the parameters of the controller are obtained.Finally,the optimized fuzzy PID control strategy is applied to the simulation of the hydraulic servo system.Compared with the optimized PID control,The tracking precision of the optimized fuzzy PID control is improved,which meets the requirements of the system operation precision,the response time is obviously accelerated,and the speed of the fast cylinder inlet and outlet ports is stable,and the speed switch and the commutation are good adaptability.The fuzzy PID control performance is still very good,and has strong robustness under the 5%load disturbance.By applying the fuzzy PID to the hydraulic cylinder servo system of the fine blanking press,it provides not only guidance for improving the performance of the hydraulic system of the fine blanking press,but also the theoretical support for the optimization design of the hydraulic system.