Pump-controlled Hydraulic Cushion Pre-accelerate The Service Research On Position Synchronization Control Strategy Of Double Cylinder

With the rapid development of the automobile industry,the market of stretch forming products puts forward higher requirements for the manufacturing process,reliability and economy of deep drawing equipment.The pump-controlled hydraulic system with compact structure and high energy utilization rate is used to replace the valve control system in the conventional hydraulic cushion,so as to form the pump-controlled hydraulic cushion will be a better product upgrade direction.The synchronous control system of pump-controlled hydraulic cushion is a complex nonlinear and time-varying electromechanical-hydraulic coupling system.The excessive coupling internal force caused by asynchrony will reduce the operating accuracy and service life of the system.In this paper,the research on dual-cylinder position synchronization control under pre-acceleration condition of pump-controlled hydraulic cushion is taken as the goal.The research is carried out from dynamic modeling,hydraulic model establishment,single-cylinder position control strategy design,dual-cylinder position synchronization control strategy design,simulation and experiment.The main research contents of this paper include :(1)The mathematical model of pump-controlled hydraulic cushion synchronous control system is established.The basic composition and working principle of pump-controlled hydraulic cushion system are analyzed.The mathematical models of servo motor and pump-controlled hydraulic cushion hydraulic system are established by vector control method and mechanism modeling method respectively.Based on the mathematical model,the position control characteristics of pump-controlled hydraulic cushion are studied,and the existing problems of the system are analyzed.(2)Determine the single-cylinder position control algorithm of the pump-controlled hydraulic pad and the synchronous control algorithm of the double-cylinder position.The boundary layer of quasi-sliding mode variable structure is designed by using the stability of fuzzy control,so as to suppress the defects of sliding mode variable structure control of its own jitter,and improve the tracking accuracy of single-pump control cylinder system during steady-state operation.Fuzzy control and PID control are introduced into the cross-coupling control part to improve the synchronization accuracy of the two-cylinder system during stable operation.(3)A simulation platform and experimental platform for the position control of pump-controlled hydraulic pads were built,and the single-cylinder position control algorithm and the double-cylinder synchronous control algorithm were simulated and experimentally verified.Simulink is used to design fuzzy adaptive sliding mode control algorithm and fuzzy PID cross-coupling control algorithm,and the prototype experimental research is carried out,and the results show that fuzzy adaptive sliding mode control can improve the position control accuracy of the system,and fuzzy PID cross-coupling control can improve the position synchronization control accuracy of the two-cylinder system.By comparing the experimental results with the simulation results,the effectiveness of the control algorithm is verified.