title: Real-time tracking control of electro-hydraulic force servo systems using offline feedback control and adaptive control.
abstract: This paper focuses on an application of an electro-hydraulic force tracking controller combined with an offline designed feedback controller (ODFC) and an online adaptive compensator in order to improve force tracking performance of an electro-hydraulic force servo system (EHFS). A proportional-integral controller has been employed and a parameter-based force closed-loop transfer function of the EHFS is identified by a continuous system identification algorithm. By taking the identified system model as a nominal plant model, an H∞offline design method is employed to establish an optimized feedback controller with consideration of the performance, control efforts, and robustness of the EHFS. In order to overcome the disadvantage of the offline designed controller and cope with the varying dynamics of the EHFS, an online adaptive compensator with a normalized least-mean-square algorithm is cascaded to the force closed-loop system of the EHFS compensated by the ODFC. Some comparative experiments are carried out on a real-time EHFS using an xPC rapid prototype technology, and the proposed controller yields a better force tracking performance improvement.
authors.affiliation: School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China; Jiangsu Key Laboratory of Mine Mechanical and Electrical Equipment, China University of Mining and Technology, Xuzhou 221116, China. Electronic address: shenganghit@163.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Shen
authors.affiliation: School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China; Jiangsu Key Laboratory of Mine Mechanical and Electrical Equipment, China University of Mining and Technology, Xuzhou 221116, China. Electronic address: zhuzhencai@vip.163.com.
authors.forename: Zhencai
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control, Yanshan University, Qinhuangdao 066004, China. Electronic address: jinsongzhao@163.com.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Mechanical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA. Electronic address: wzhu@umbc.edu.
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhu
authors.affiliation: School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China; Jiangsu Key Laboratory of Mine Mechanical and Electrical Equipment, China University of Mining and Technology, Xuzhou 221116, China. Electronic address: tangyumail@126.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Tang
authors.affiliation: School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou 221116, China; Jiangsu Key Laboratory of Mine Mechanical and Electrical Equipment, China University of Mining and Technology, Xuzhou 221116, China. Electronic address: lixiang_nn@126.com.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
keywords: Adaptive control; Electro-hydraulic force servo system; H(∞) control; Least-mean-square algorithm; System identification