Title: Position servo with variable speed pump-controlled cylinder: design, modelling and experimental investigation

Authors: Haigang Ding; Yalong Li; Quanmin Zhu; Jingyi Su

Addresses: School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu, China; State Key Laboratory of Intelligent Mining Equipment Technology, Xuzhou, Jiangsu, China ' School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu, China ' Department of Engineering Design and Mathematics, University of the West of England, Bristol 161QY, UK ' School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, Jiangsu, China

Abstract: This paper proposes a position servo system with variable-speed pump-controlled cylinder (VSPC), which controls an asymmetric cylinder in four quadrants by adjusting servomotor speed, and elucidates the system working principle. The system mathematical model is established, an anti-integral saturation PID controller is designed, and the resonance frequency and damping ratio are obtained. The system simulation model and experimental bench are established, and step response and sinusoidal tracking experiments are carried out, revealing the change rule of servomotor speed and torque, and analysing the gas volume and pressure change process of accumulators. The results show that the actuator can accurately and quickly track the command signal under positive and negative loads by regulating the pump speed; when the cylinder position is unchanged, the motor operates at low speed with a fixed steering to compensate for system leakage and maintain pressure to keep the desired position.

Keywords: variable speed pump control; variable-speed pump-controlled cylinder; VSPC; position servo; resonance frequency; four quadrants; servomotor.

DOI: 10.1504/IJHM.2024.138267

International Journal of Hydromechatronics, 2024 Vol.7 No.2, pp.155 - 175

Received: 24 Aug 2023
Accepted: 07 Oct 2023
Published online: 30 Apr 2024 *