Adaptive second-order sliding mode control with uncertainty compensation

ABSTRACT

This paper endows the second-order sliding mode control (2-SMC) approach with additional capabilities of learning and control adaptation. We present a 2-SMC scheme that estimates and compensates for the uncertainties affecting the system dynamics. It also adjusts the discontinuous control effort online, so that it can be reduced to arbitrarily small values. The proposed scheme is particularly useful when the available information regarding the uncertainties is conservative, and the classical `fixed-gain’ SMC would inevitably lead to largely oversized discontinuous control effort. Benefits from the viewpoint of chattering reduction are obtained, as confirmed by computer simulations.

Keywords:

• Second-order sliding modes
• uncertain systems
• nonlinear systems
• adaptation

Acknowledgments

A. Pisano and E. Usai acknowledge the financial support from the Region of Sardinia under project ‘Modeling, control and experimentation of innovative systems for thermal energy storage’, grant number CRP-60913.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Region of Sardinia [grant number CRP-60913].