Adaptive tracking control of uncertain large-scale nonlinear time-delay systems with input saturation

Abstract

This paper investigates the adaptive tracking control problem of uncertain large-scale nonlinear time-delay systems with input saturation. Unknown constants and continuous functions with respect to output or delayed output are allowed in the nonlinear interconnected functions. The dynamic gain control technique is used to study the tracking control problem of considered system, which simplifies design process and form of controller. By introducing a full-order state observer and three dynamic equations, output feedback tracking control scheme is constructed to ensure that all signals of the closed-loop system are globally uniformly ultimately bounded (GUUB). In addition, the tracking error can converge to a small neighbourhood around the origin by selecting appropriate parameters. Finally, a practical example is presented to illustrate the feasibility of the proposed control scheme.

Keywords:

• Uncertain large-scale systems
• input saturation
• tracking
• dynamic gain control technique

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [grant numbers 61973189 and 61873334], the Research Fund for the Taishan Scholar Project of Shandong Province of China [grant number ts20190905], and the Natural Science Foundation of Shandong Province of China [grant number ZR2020ZD25].

Notes on contributors

Zhiyu Duan

Zhiyu Duan is a present master student with the School of Control Science and Engineering, Shandong University, China. Her current research interests include nonlinear systems and saturation control.

Lingyu Kong

Lingyu Kong is currently the associate dean of scientific research of School of Mechanical and Electrical Engineering, director of Mechanical and Electrical Engineering Research Center of Shandong Yingcai University, etc. He has presided over one project of National Natural Science Foundation of China, one project of National Innovation Fund for Small and Medium Enterprises, and one general project of Natural Science Foundation of Shandong Province, etc. His research interests include new sensing detection and its complex process control.

Debao Fan

Debao Fan is presently a master's student with the School of Control Science and Engineering, Shandong University, China. His current research interests include nonlinear systems and multi-agent systems.

Xianfu Zhang

Xianfu Zhang received the M.Sc. degree in Mathematics from the School of Mathematics Sciences, Shandong Normal University, China, in 1999, and the Ph.D. degree in Operational Research and Control from the School of Mathematics, Shandong University, China, in 2005. From 1999 to 2011, he worked in the School of Science, Shandong Jianzhu University, China. He joined the School of Control Science and Engineering, Shandong University, China, in 2012, where he is currently a professor. From September 2008 to February 2009, he was a visiting scholar in the Department of Mechanical Engineering, Ecole Polytechnique de Montreal, Canada. From November 2009 to February 2010, and from July 2012 to October 2012, he was a research assistant in City University of Hong Kong, Hong Kong. His main research interests include nonlinear systems, fractional-order systems, and time-delay systems. He received the Prize of Shandong Natural Science in 2017, and he was recognized as the Taishan Scholar Distinguished Professor of Shandong Province in 2019.