Simultaneous state and output disturbance estimations for a class of switched linear systems with unknown inputs

ABSTRACT

The paper considers the issues of state estimation and output disturbance reconstruction for a class of switched linear systems with unknown inputs. A singular switched system is derived from the original switched system by taking the output disturbance as a part of a new extended state vector. For the constructed singular switched system, a robust sliding-mode switched observer which can not only estimate the states of original switched system but also reconstruct output disturbances is proposed, where the switching of the observer is synchronous with that of the switched system. A sufficient condition is provided to guarantee the existence of the switched observer by the feasibility of an optimisation problem with linear matrix inequality constraint, and the corresponding switching signal with average dwell time is designed such that the convergence of the estimation error system is proven to be exponential. Based on the state estimation of singular switched system, the methods of state estimation and output disturbance reconstruction of original switched system are proposed. Finally, the simulation results confirm the predicted performance of the proposed methods.

KEYWORDS:

• Uncertain switched system
• switched observer
• output disturbance
• unknown input

Acknowledgements

The authors would like to thank the editors and anonymous reviewers for their time and effort spent in handling the paper as well as many constructive comments provided for improving much further the presentation and quality of the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

National Nature Science Foundation of China [grant number 61403129], [grant number 61573129]; Programme of Key Young Teacher of Henan Province Higher School [grant number 2015GGJS-064]; Doctoral Fund Program of Henan Polytechnic University [grant number B2015-30]; Fund of Key Laboratory of Control Engineering of Henan Province [grant number KG2014-08]; Program of Natural Science of Henan Provincial Education Department [grant number 13B413028], [grant number 13B413035].

Notes on contributors

Junqi Yang

Junqi Yang was born in 1979. He received his BS degree in computer science and technology from Henan Polytechnic University, Jiaozuo, China, in 2002; MS degree in control theory and control engineering from China Three Gorges University, Yichang, China, in 2005; and PhD degree in control theory and control engineering from Tongji University, Shanghai, China, in 2013. He is currently an associate professor of Henan Polytechnic University. His research interests include state estimation, system identification, model-based fault detection and hybrid system.

Yantao Chen

Yantao Chen received her MS degree in control theory and control engineering from China Three Gorges University, Yichang, China, in 2005. She is currently a lecturer of Henan Polytechnic University. Her research interests include parameter estimation and fault-tolerant control.

Fanglai Zhu

Fanglai Zhu received his PhD degree in control theory and control engineering from Shanghai Jiao Tong University in 2001. Now he is a professor of Tongji University, China. His research interests include nonlinear observer design, system identification, and model-based fault detection and isolation.

Fuzhong Wang

Fuzhong Wang received his PhD degree in automation from China University of Mining and Technology. He is currently a professor of College of Electrical Engineering and Automation in Henan Polytechnic University. His research interests include industrial process control, artificial intelligent control, modeling and simulation of control system, electrical system operation and control.