Research On Bidirectional Double Closed Loop Synchronous Control Of Proportional Valve-Controlled Combination Cylinder

In many applications where multi-cylinder position synchronization is required,it not only requires the hydraulic cylinder to have high tracking and synchronization accuracy in both directions,but also satisfies the control requirements for speed,but due to the coupling between the cylinders,external disturbances,and the complex variability of the load.,making it difficult to achieve a good control effect.This paper takes pre-bending machine as the research object,and studies the synchronous control system of the proportional valve-controlled combination cylinder.According to its hydraulic working principle,the mathematical model of the synchronous control system is established,and the nonlinear factors existing in the synchronous control system are analyzed.The corresponding control strategies are formulated for the single axis control and the four axis control.Considering the influence of load on speed stability and position accuracy,a four-axis synchronous control strategy based on double-closed-loop control of position and speed with single axis and load compensation is proposed.For single-axis simultaneous control of position and speed characteristics,a double closed-loop control method for outer-loop position control and inner-loop speed control is used;for the four-axis synchronization,two sets of master-slave synchronization are used,and the synchronous synchronization between the two sets of spindles adopts mean synchronization..In order to verify the feasibility of the proposed control strategy,the system was co-simulated with AMEsim and Simulink.The simulation results show that the proposed control strategy achieves bi-directional high synchronization precision and speed tracking accuracy under different loads,different interferences,and different control methods.This not only satisfies the control requirements of the actual production process of the pre-bending machine,but also provides a valuable theoretical basis and application reference for the research and application of the hydraulic synchronous system.