Stability analysis and adaptive control for nonlinear discrete-time systems with time delays and dead zone via state-feedback technique

摘要

This research addresses the stability analysis and adaptive state-feedback control for a class of nonlinear discrete-time systems with multiple interval time-varying delays and symmetry dead zone. The multiple interval time-varying delays and symmetry dead zone are considered in the nonlinear discrete-time system. The multiple interval time-varying delays are bounded by the nonlinear function with unknown coefficients, and the symmetry dead zone is considered without the knowledge of the dead zone parameters. The adaptive state-feedback controller is designed for the nonlinear discrete-time systems with multiple interval time-varying delays and dead zone. The discrete Lyapunov-Krasovskii functional is introduced, such that the solutions of the closed-loop error system converge to an adjustable bounded region and the state errors can be rendered arbitrarily small by adjusting the adaptive parameters. The designed adaptive state-feedback controller does not require the knowledge of maximum and minimum values for the characteristic slopes of the dead zone. Finally, three simulation examples are given to show the effectiveness of the proposed methods.