I. Introduction
Axial piston pumps have been widely used in hydraulic system because of their excellent stability, high working pressure and good applicability. However, they can generate significant pressure ripple which may decrease the performance of hydraulic system and product noise caused by fluid, while in hydraulic pipeline system, the fluid-borne noise interact with the system structure and causes vibration [1]. In order to weaken the fluid-borne noise of hydraulic systems, lots of pulsation attenuators have been presented, such as spring-loaded hydraulic suppressors [2], porous-concentric hydraulic mufflers [3], bladder accumulators [4] and Helmholtz attenuators [5], among which bladder accumulators and Helmholtz attenuators are categorized as the resonant pulsation attenuator.