Distributed robust control for synchronised tracking of networked Euler–Lagrange systems

Abstract

In this paper, we propose a distributed robust control method for synchronised tracking of networked Euler–Lagrange systems, where the time-varying reference trajectory is sent to only a subset of the agents. It is assumed that the agents can exchange information with their local neighbours on a bidirectionally connected communication graph. In the local controller equipped in each generalised coordinate of the agents, a disturbance observer is introduced to compensate for the low-passed-coupled uncertainties, and a sliding mode control term is employed to handle the uncertainties that the disturbance observer cannot compensate for sufficiently. By some damping terms, the boundedness of the signals of the overall networked nonlinear systems is first ensured. Then we show how the disturbance observer and sliding mode control term play in a cooperative way in each local generalised coordinate to achieve an excellent synchronised tracking performance. Simulation results are provided to support the theoretical results.

Keywords:

• multi-agent systems
• Euler–Lagrange systems
• distributed control
• synchronised control
• sliding mode control
• disturbance observer

Additional information

Notes on contributors

Zi-Jiang Yang

Zi-Jiang Yang was born in 1964. He received the DrEng degree from Kyushu University, Fukuoka, Japan, in 1992. He was an Assistant Professor from 1992 to 1996, and an Associate Professor from 1996 to 2001, with Kyushu Institute of Technology, Japan. From 2001 to 2009, he was an Associate Professor with Kyushu University. Since 2009, he has been a Professor with the Department of Intelligent Systems Engineering, Faculty of Engineering, Ibaraki University, Ibaraki, Japan. His research interests include system identification and nonlinear system control.

Yoshiyuki Shibuya

Yoshiyuki Shibuya was born in 1989. He received the BS degree from the Department of Intelligent Systems Engineering, Faculty of Engineering, Ibaraki University, Ibaraki, Japan, in 2011, where he is currently pursuing the MS degree from the Graduate School of Science and Engineering. His research interests include nonlinear system control.

Pan Qin

Pan Qin received the ME degree from Northwestern Polytechnical University, China, in 2004 and the PhD degree from Kyushu University, Japan, in 2008. He worked as a postdoctoral researcher with the Faculty of Mathematics, Kyushu University, from 2008 to 2009. He is currently a research fellow with Institute of Mathematics for Industry (IMI), Kyushu University, Japan. His research interests include control theory, system identification and statistical modelling.