Adaptive control of time‐delay nonlinear HOFA systems with unmodeled dynamics and unknown dead‐zone input
Liuliu Zhang, Peng Wang, Changchun Hua
Abstract
Abstract This paper focuses on the control problem of time‐delay nonlinear high‐order fully actuated (HOFA) systems with unmodeled dynamics and unknown dead‐zone input. The primary objective of this paper is to design an adaptive controller by using the HOFA systems approach. To do so, we need to tackle some technical obstacles. Firstly, in order to deal with unmodeled dynamics in the HOFA systems, the technique of changing the supply rate is combined with the HOFA systems approach. Secondly, an adaptive dead‐zone inverse is constructed to compensate for the influence of the unknown asymmetrical dead‐zone input nonlinearity. Then, the controller is designed by the HOFA systems approach, and it is proved that all states of the systems converge to a bounded region based on the Lyapunov‐Krasovskii functions. Finally, the simulation results demonstrate the effectiveness of the designed adaptive controller.