title: Coupled-disturbance-observer-based position tracking control for a cascade electro-hydraulic system.
abstract: The disturbance suppression is one of the most common control problems in electro-hydraulic systems. especially largely an unknown disturbance often obviously degrades the dynamic performance by biasing the desired actuator outputs (e.g., load forces or torques). In order to reject the dynamic disturbances in some multi-degree-of-freedom manipulators driven by electro-hydraulic actuators, this paper proposes a state feedback control of the cascade electro-hydraulic system based on a coupled disturbance observer with backstepping. The coupled disturbance observer is designed to estimate both the independent element and the coupled element of the external loads on each electro-hydraulic actuator. The cascade controller has the ability to compensate for the disturbance estimating, as well as guarantees the system state error convergence to a prescribed steady state level. The effectiveness of the proposed controller for the suppression of largely unknown disturbances has been demonstrated by comparative study, which implies the proposed approach can achieve better dynamic performance on the motion control of Two-Degree-of-Freedom robotic arm.
authors.affiliation: School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, 611731 Chengdu, China. Electronic address: guoqinguestc@uestc.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Guo
authors.affiliation: School of Aeronautics and Astronautics, University of Electronic Science and Technology of China, 611731 Chengdu, China. Electronic address: yinjm1028@163.com.
authors.forename: Jing-Min
authors.initials: JM
authors.lastname: Yin
authors.affiliation: Center for Power Transmission and Motion Control, Department of Mechanical Engineering, University of Bath, BA2 7AY Bath, UK. Electronic address: ty267@bath.ac.uk.
authors.forename: Tian
authors.initials: T
authors.lastname: Yu
authors.affiliation: School of Mechatronics Engineering, University of Electronic Science and Technology of China, 611731 Chengdu, China. Electronic address: jdan2002@uestc.edu.cn.
authors.forename: Dan
authors.initials: D
authors.lastname: Jiang
keywords: Cascade controller; Coupled disturbance observer; Electro-hydraulic system; Two-Degree-of-Freedom robotic arm