Novel disturbance-observer-based control for systems with high-order mismatched disturbances

ABSTRACT

A novel disturbance-observer-based control method is investigated to attenuate the high-order mismatched disturbances. First, a finite-time disturbance observer (FTDO) is proposed to estimate the disturbances as well as the derivatives. By incorporating the outputs of FTDO, the original system is then reconstructed, where the mismatched disturbances are transformed to the matched ones that are compensated by feed-forward algorithm. Moreover, a feedback control law is developed to achieve the stability and tracking performance requirements for the systems. Finally, the proposed composite control method is applied to an unmanned helicopter system. The simulation results demonstrate that the proposed control method exhibits excellent control performance in the presence of high-order matched and mismatched disturbances.

KEYWORDS:

• High-order mismatched disturbances
• finite-time disturbance observer (FTDO)
• disturbance-observer-based control (DOBC)
• system reconstruction
• unmanned helicopters

Acknowledgments

The authors gratefully acknowledge the associate editor and reviewers for their helpful comments and suggestions, which have improved the quality of this article.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by the Natural Science Foundation of China [grant number 61473137], [grant number 61703118]; and the Fundamental Research Funds for the Central Universities [grant number JUSRP11744].

Notes on contributors

Xing Fang

Xing Fang was born in 1987. He received his PhD degree in control theory and engineering from Tianjin University, Tianjin, China in 2016. He is now a lecturer in Institute of Automation, Jiangnan University, Wuxi, China. His research interests include flight control systems, disturbance rejection and robust control.

Fei Liu

Fei Liu was born in 1965. He received his PhD degree in control theory and engineering from Zhejiang University, Hangzhou, China in 2002. He is now a professor in Institute of Automation, Jiangnan University, Wuxi, China. His research interests include process control system, markov jumping system and robust control.

Zhiguo Wang

Zhiguo Wang was born in 1977. He received his PhD degree in control theory and engineering from Jiangnan University, Wuxi, China in 2013. He is now an associate professor in Institute of Automation, Jiangnan University, Wuxi, China. His research interests include process control system and robust control.

Na Dong

Na Dong was born in 1982. She received her PhD degree in control theory and engineering from Nankai University, Tianjin, China in 2011. She is now an associate professor in School of Electrical Engineering and Automation, Tianjin University, Tianjin, China. Her research interests include flight control systems, data-driven control and robust control.