Predefined Output Adaptive Tracking Control for Switched Nonlinear Systems with Unknown Control Directions and Full States Time-Varying Constraints

This article explores the challenge of adaptive tracking control for switched nonlinear systems with unspecified control directions. To address this issue, we employ Nuss-baum gain technology to tackle unknown control directions. Additionally, the utilization of a time-varying symmetric bar-rier Lyapunov function (BLF), in conjunction with the tuning function method, was employed to guarantee compliance with the entire state constraint. Moreover, a predefined specific moment is established, and the output of the system is ensured to adhere to the constraint prior to reaching the designated point through the incorporation of the shift function nested within the initial BLF. The efficacy of the proposed method is substantiated through an example of simulation.