Research on the position–pressure cooperative control strategy for full-hydraulic leveler

Abstract

The characteristics of electro-hydraulic servo system of full-hydraulic leveler are high speed, large inertia, high frequency response, and multi-degree of freedom. In order to improve the degree of automation of full-hydraulic leveler and achieve the simultaneous control between position and pressure, the position–pressure cooperative control strategy is presented in the article. In the working process, the dynamic working pressure signal of the hydraulic cylinder is turned into a real-time position signal by the pressure–position conversion gain and then compensates the converted signal into the position closed loop. Meanwhile, the pressure signal of the rear cavity of the hydraulic cylinder is fed back to the input of the proportional relief valve at the pump source, and then the system work pressure changes quickly according to the different thickness. In this article, the mathematical model of position–pressure cooperative control of hydraulic straightening machine is established. The simulation results in AMESim software verify the correctness of the control strategy. Finally, the feasibility and practicability of the control strategy are verified by the field prototype of 11-roller full-hydraulic leveler. The control strategy provides the theoretical basis for designing the electro-hydraulic servo system.