Robust nonlinear control of a three-tank system using finite-time disturbance observers. (March 2019)

• Record Type: Journal Article
• Authors: Yang, Zi-Jiang; Sugiura, Hiroyuki
• Is Part Of: Control engineering practice. Volume 84(2019)
• Page Start: 63
• Page End: 71
• Publication Date: 2019-03
• Subjects: Finite-time disturbance observer -- Backstepping design -- Dynamic surface control -- Mismatched uncertainty -- Three-tank system; Automatic control -- Periodicals; 629.89
• DOI: 10.1016/j.conengprac.2018.11.013
• Languages: English
• ISSNs: 0967-0661

Abstract

Abstract: A finite-time disturbance observer-based robust control method is proposed for output tracking of the Inteco threetank system in the presence of mismatched uncertainties. The controller is designed in a backstepping manner. At each step of the virtual controller design, a robust feedback controller with some effective nonlinear damping terms is designed so that the system states remain in the feasible domain. The nonlinear uncertainty is compensated by a finite-time disturbance observer. And to avoid the shortcoming of "explosion of terms", the dynamic surface control technique which employs a low-pass filter is adopted at each step of the virtual controller design. Attention is paid to reducing the measurement noise effects and to initialization technique of the system states and reference output trajectory. Theoretical analysis is performed to clarify the control performance. And the theoretical results are verified based on the experimental studies on the real Inteco three-tank system. Highlights: A robust nonlinear control method for a three-tank system is proposed. The system is viewed as a semi-strict feedback system. Backstepping design and finite-time disturbance observers are used. The method is verified by experiments on the Inteco Three-tank system.