Finite-time dynamic surface control using a novel nonlinear filter for nonlinear systems with input saturation and output constraint

Abstract

This paper proposes a finite-time dynamic surface control (FTDSC) scheme using a novel nonlinear filter for nonlinear systems with input saturation and output constraint. The FTDSC scheme featured by nonlinear filter is presented to overcome the drawback of the traditional DSC scheme using first-order linear filter. The barrier Lyapunov function (BLF) is used to handling output constraint and the disadvantage of conventional input saturation problem is solved through introducing a nonlinear smooth function. In order to deal with the impact of external disturbance, the nonlinear disturbance observer (NDO) is introduced to estimate the disturbance. It is proved that All signals are semi-globally uniformly ultimately bounded (SGUUB) in the closed loop system. Moreover, the tracking error can convergences to a neighborhood of zero through the proper designed parameters. Comparison studies are conducted to verify that the proposed FTDSC scheme comparing with the traditional DSC scheme has the more accurate tracking capability.

KEYWORDS:

• Finite-time dynamic surface control
• barrier Lyapunov function
• backstepping technique
• nonlinear disturbance observer
• input saturation
• output constraint

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation (NNSF) of China under grant number [62073335], and the China Postdoctoral Science Foundation [2017M613201, 2019T120944, 2020M683737].