Research on a High-Frequency Response Direct Drive Valve System Based on Voice Coil Motor

Improving frequency response of direct drive valve (DDV) system is a research focus on the hydraulic system. This paper presents a high-frequency response DDV system based on voice coil motor (VCM-DDV). First, a new design of VCM with high acceleration is proposed. A magnetic circuit method and electromagnetic finite element method are adopted in this paper. A 3-D thermal field element method is also employed to analyze the temperature rise of the developed VCM at rated current. Next, a dual closed-loop control structure is applied in the developed VCM-DDV system. Moreover, a nonlinear PID control strategy is proposed to resolve the contradiction between stability and rapidity. The results of performance test indicate that the acceleration of the developed VCM is evidently improved, and it reaches 306 times of gravity acceleration. Experimental investigation indicates that the developed VCM-DDV system has excellent static and dynamic performances. The position bandwidth of the developed VCM-DDV is capable of achieving 350 Hz.