Research On Synchronous Control Method Of Four-cylinder Isothermal Forging Hydraulic Press Based On Fuzzy Sliding Mode Algorithm

With the rapid development of aerospace technology and automobile industry,the demand of isothermal forging hydraulic press with high precision,high speed and high automation level is increasing.The working principle of most isothermal forging hydraulic press is driving the beam to suppress the deformation of the blank by multi cylinder.There has a very high demand for the synchronization of multi hydraulic cylinder in the driving process.Therefore,it becomes more and more important to study the synchronous control algorithm of multi cylinder system.In recent years,the research of intelligent control algorithm and various kinds of complex control algorithms attracts more attention,which provides a new idea to solve the problem of multi-cylinders synchronization.In this paper,the synchronous control of YH10-4000 isothermal forging hydraulic press is studied.The main research contents are as follows:(1)Analyze the reasons for the phenomenon of the non synchronism in the process of the beam movement through the establishment of the mathematical model of the movable beam.Then design the hydraulic system and control system of four cylinder isothermal forging hydraulic press.(2)Establish the mathematical model of electro-hydraulic proportional valve and valve controlled asymmetrical hydraulic cylinder based on the analysis of the dynamic performance of electro-hydraulic proportional valve and hydraulic cylinder.Determine the relevant parameters,and then get the transfer function of the system.According to the step response of the system,it is obvious that the system has a large oscillation.So it is necessary to join the correction to improve the stability of the system.(3)Introduce the sliding mode variable structure control and fuzzy control.In this chapter,a control method combining fuzzy control with sliding mode variable structure control is designed.The method improve the control effect of sliding mode variable structure effectively.(4)AMESim/Simulink is used to simulate the system and the result shows that the fuzzy sliding mode variable structure control method designed in this paper has better control precision and robustness.