Acceleration tracking control combining adaptive control and off-line compensators for six-degree-of-freedom electro-hydraulic shaking tables. (September 2017)

• Record Type: Journal Article
• Authors: Shen, Gang; Li, Xiang; Zhu, Zhencai; Tang, Yu; Zhu, Weidong; Liu, Shanzeng
• Is Part Of: ISA transactions. Volume 70(2017:Sep.)
• Page Start: 322
• Page End: 337
• Publication Date: 2017-09
• Subjects: Electro-hydraulic shaking table -- Adaptive control -- Least-mean-squares algorithm -- Recursive extended least-squares algorithm -- Off-line inverse model compensator -- System identification; Engineering instruments -- Periodicals; Engineering instruments; Periodicals; Electronic journals; 629.805
• DOI: 10.1016/j.isatra.2017.07.018
• Languages: English
• ISSNs: 0019-0578

Abstract

Abstract: An electro-hydraulic shaking table (EHST) is an essential experimental facility to simulate in real-time actual vibration situations. An adaptive controller combined with off-line compensators is proposed to improve the acceleration frequency bandwidth and tracking accuracy of a six-degree-of-freedom (6-DOF) EHST. A servo controller has been employed to implement acceleration closed-loop and coordinate control of the 6-DOF EHST. A recursive extended least-squares algorithm is employed to identify acceleration closed-loop transfer functions and a zero-phase-error tracking controller is used to design off-line inverse model compensators using the identified transfer functions. However, the off-line compensators cannot compensate in real-time varying dynamics of the 6-DOF EHST; so an online adaptive controller with a least-mean-squares (LMS) algorithm based on a delay compensator is employed. The proposed controller combines advantages of the off-line compensators and the online adaptive controller, which guarantees both a fast rate of convergence of the LMS algorithm and high-fidelity acceleration tracking accuracy of the 6-DOF EHST. Some experimental studies have been conducted on a 6-DOF EHST and experimental results show that acceleration tracking control performances, including the rate of convergence of the LMS algorithm and acceleration tracking accuracy, have been improved compared to a conventional three-variable controller and adaptive controllers. Highlights: Acceleration closed-loop transfer functions are identified and their inverse models are designed. A three-variable controller, an inverse model controller, and a delay compensator are designed. A novel controller combining off-line compensators with an adaptive controller is proposed. Experimental results improve acceleration tracking accuracy on a 6-DOF electro-hydraulic shaking table.