Subspace-based continuous-time identification of fractional order systems from non-uniformly sampled data

Abstract

This work focuses on the identification of fractional commensurate order systems from non-uniformly sampled data. A novel scheme is proposed to solve such problem. In this scheme, the non-uniformly sampled data are first complemented by using fractional Laguerre generating functions. Then, the multivariable output error state space method is employed to identify the relevant system parameters. Moreover, an in-depth property analysis of the proposed scheme is provided. A numerical example is investigated to illustrate the effectiveness of the proposed method.

Keywords:

• fractional order systems
• continuous-time identification
• non-uniformly sampled data
• fractional Laguerre generating functions
• subspace identification methods

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (grant number 61004017) and the National 863 Project of China (grant number 2011AA7034056).

Notes on contributors

Yangsheng Hu

Yangsheng Hu received his BEng degree in automation from Xidian University, in 2013. He is currently a Master degree candidate at the University of Science and Technology of China. His research interests include fractional order system identification and active disturbance rejection control.

Yuan Fan

Yuan Fan received BEng degree in Automation from the University of Science and Technology of China, Hefei, China, in 2006, and PhD degrees in Control Science and Engineering both from the University of Science and Technology of China and the City University of Hong Kong in 2011. He was a senior research associate in the Department of Mechanical and Biomedical Engineering, City University of Hong Kong, from July to September 2013. He has been with Anhui University since 2011, where he is currently an Associate Professor. His main research interests include networked dynamic systems, distributed control, multi-agent coordination, intelligent systems and control, and robotics.

Yiheng Wei

Yiheng Wei received his BEng degree in automation from Northeastern University in 2010. He is currently a PhD candidate of Automation at the University of Science and Technology of China. His research interests include fractional order systems analysis and controller synthesis.

Yong Wang

Yong Wang received his BEng degree in automatic control from the University of Science and Technology of China, Hefei, China, in 1982, and MEng and PhD degrees in navigation, guidance, and control from Nanjing Aeronautical Institute, Nanjing, China, in 1985 and 1999, respectively. He has been with the Department of Automation, University of Science and Technology of China since 2001, where he is currently a professor. He has published more than 260 refereed journal and conference papers. His research interests include active vibration control, vehicle guidance and control and fractional order dynamic and control.

Qing Liang

Qing Liang received his BEng degree in automatic control in 1983 and MEng degrees in control theory and applications in 1986 from the University of Science and Technology of China, Hefei, China. He is currently an Associate Professor in the Department of Automation, University of Science and Technology of China. His research interests include vibration control, robotics, motor control, and intelligent information processing.