Active control of fluid pressure pulsation in hydraulic pipe system by bilateral-overflow of piezoelectric direct-drive slide valve

In this paper, a novel active control of fluid pressure pulsation (ACFPP) is proposed, which meets the need of the high-pressure and high-speed hydraulic pipe system. A piezoelectric direct-drive slide valve (PDDSV) is designed and used as the active vibration absorber. Two ports of the PDDSV both connect to a bypass near the pump outlet and the other two ports both connect to the oil tank. By the bilateral-overflow through the shoulder of the PDDSV, the overflow wave generated in one cycle of spool motion can cancel two cycles of flow ripple. An adaptive-optimum control method based on the rotate-vector optimization method (RVOM) is adopted to adjust the control parameters in order to minimize the amplitude of the pressure pulsation. The biggest advantage of the proposed ACFPP is that it can eliminate the pressure pulsation when PDDSV only works at half of the pressure pulsation's frequency. The simulation and experimentation both verify the proposed ACFPP. By the proposed ACFPP, the suppression for the singlefrequency component and dual-frequency components of the pressure pulsation have been both realized.