IMPROVING ELECTRO-HYDRAULIC SYSTEM PERFORMANCE BY DOUBLE-VALVE ACTUATION

Restricted by narrow bandwidth of the existing high-flow servo valves, dynamic performance of high-flow electro-hydraulic servo systems can only be enhanced to a certain extent by advanced control algorithms. This paper proposes a new hydraulic control circuit, in which two valves are arranged in parallel to control the actuator jointly. Frequency response of the equivalent valve is raised and thereby the performance of high-flow electro-hydraulic servo systems can be improved. A model of the proposed system is built and the principle of improving system dynamic performance using the new circuit is analyzed. Simulation results show that double-valve actuation schemes can quicken system response and increase system bandwidth regardless to if the two valves have the same or different behaviors.