Session: Controls 1

Paper Number: 111744

111744 - Bandwidth Expansion and Resonant Suppression for High-Frequency Electro-Hydraulic Acceleration Control System by Combining Dynamic Pressure Feedback and Three-Variable Control 

Due to the characteristics of high-power density, high-frequency electro-hydraulic acceleration control system (HEACS) has been an important component of vibration simulation equipment such as load simulators, underwater acoustic simulators, and fatigue testing machines. However, the performance of the HEACS is strongly restricted by the inherent low bandwidth and low damping ratio of the electro-hydraulic subsystem. Generally, these two shortcomings must be traded off to achieve desired compromise performance. To expand the bandwidth and increase the damping ratio of the electro-hydraulic subsystem at the same time, a novel control method combining dynamic pressure feedback with the three-variable controller (TVC) was proposed in this work. Firstly, the dynamic model of the high-frequency electro-hydraulic subsystem was established, and the basic TVC was designed to expand the bandwidth and lightly suppress the resonance of the electro-hydraulic subsystem previously. Secondly, the dynamic pressure was estimated and introduced into the control scheme for increasing the damping ratio of the system, which could suppress the resonance of the system more effectively. Thirdly, simulations and experiments of acceleration power spectrum density (PSD) repetition of the HEACS were conducted to verify the effectiveness of the proposed control method. Experiments results show that the maximum bandwidth of the electro-hydraulic subsystem with PID controller was about 150Hz, the bandwidth of the system with the traditional TVC method was expanded to nearly 300Hz with apparent resonance, while the bandwidth of the system with the proposed method was expanded from 150Hz to 300Hz as well without any resonance, and only the HEACS with the proposed method could achieve the acceleration PSD repetition within the tolerance of ±3dB. Thus, the superior performance of the proposed method in increasing the system bandwidth and reducing the system resonance simultaneously was demonstrated.

Presenting Author: Guifu Luo State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University

Presenting Author Biography: Guifu Luo received the B.S. degree in the College of Mechanical and Electrical Engineering from Central South University, Changsha, China, in 2018, and he is currently a Ph.D. candidate in the State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China.
His research interests include electro-hydraulic system control, dynamics modelling and control of biped robots.