Nonlinear disturbance observer based sliding mode control for a benchmark system with uncertain disturbances

Xianqing Wu; Yijiang Zhao; Kexin Xu

doi:10.1016/j.isatra.2020.10.032

Nonlinear disturbance observer based sliding mode control for a benchmark system with uncertain disturbances

ISA Trans. 2021 Apr:110:63-70. doi: 10.1016/j.isatra.2020.10.032. Epub 2020 Oct 21.

Authors

Xianqing Wu¹, Yijiang Zhao², Kexin Xu³

Affiliations

¹ Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, China. Electronic address: wxq@zstu.edu.cn.
² Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, China. Electronic address: yijiangz1996@163.com.
³ Faculty of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, China. Electronic address: xukexinskkk@163.com.

PMID: 33121735
DOI: 10.1016/j.isatra.2020.10.032

Abstract

Taking uncertain disturbances into account, the control problem of the translational oscillator with a rotational actuator (TORA) is considered in this paper. Motivated by the desire to attenuate influences from unknown disturbances/uncertainties, the disturbance-observer-based methodology is utilized. Specifically, a system model with a cascade structure for the TORA system is obtained after a series of coordinate transformations. Then, inspired by the backstepping control technique, for the first subsystem, a virtual control variable is introduced and an error-signal-based system is designed. Next, an estimator is presented and used to estimate unknown disturbances, based upon which a sliding mode control approach is devised to ensure the underactuated TORA system is asymptotically stable at the origin. Finally, the applicability and robustness of the designed control method are examined via three group numerical simulation tests.

Keywords: Disturbance observer; Sliding mode control; TORA; Underactuated system.