Investigation on the dynamic characteristics and control accuracy of a novel proportional directional valve with independently controlled pilot stage

Junhui Zhang; Zhengyu Lu; Bing Xu; Qi Su

doi:10.1016/j.isatra.2019.03.023

Investigation on the dynamic characteristics and control accuracy of a novel proportional directional valve with independently controlled pilot stage

ISA Trans. 2019 Oct:93:218-230. doi: 10.1016/j.isatra.2019.03.023. Epub 2019 Mar 27.

Authors

Junhui Zhang¹, Zhengyu Lu², Bing Xu³, Qi Su⁴

Affiliations

¹ The State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, No.38 Zheda Road, Hangzhou, 310027, China. Electronic address: benzjh@zju.edu.cn.
² The State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, No.38 Zheda Road, Hangzhou, 310027, China. Electronic address: luzhenyu@zju.edu.cn.
³ The State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, No.38 Zheda Road, Hangzhou, 310027, China. Electronic address: bxu@zju.edu.cn.
⁴ The Shanghai Aerospace Control Technology Institute, China Aerospace Science and Technology Corporation, No.1555 Zhongchun Road, Shanghai, 201109, China. Electronic address: 06jxlsq@zju.edu.cn.

PMID: 30987805
DOI: 10.1016/j.isatra.2019.03.023

Abstract

The pilot operated directional valves are widely used in hydraulic systems. For the purpose to improve the dynamic characteristics and control accuracy of the traditional valve, this paper proposes a novel pilot valve that employs two independent valve spools instead of the traditional port coupled valve spool. Due to the new structure, the influence of deadzone and damping on the performance of the valve is lightened; the dynamic characteristics and control accuracy of the valve are improved. Both of the open-loop simulation and experimental closed-loop position control of the entire valve demonstrate that the novel valve has impressive performance improvement of the entire valve. The results of experiments show that the -3dB-frequency of novel valve improves 61.5% in the case of single side control mode (SS) and 57.1% in the case of both side control mode (BS); the tracking error decreases from 6.21% to 2.6% in the case of SS and from 7.48% to 3.96% in case of BS.

Keywords: Deadzone; Dynamic characteristics; Independent controlled pilot stage; Pilot operated directional valve; Position tracking control.