Practical finite-time fuzzy control of uncertain nonstrict-feedback systems with actuator saturation and output constraints

This article investigates the devise issue of a practical finite-time output-tracking control for uncertain nonlinear nonstrict-feedback systems subject simultaneously to time-varying output constraints (TVOC), actuator saturation, and bounded unmatched disturbances. An adaptive fuzzy approximator-based control system is devised using the dynamic surface control (DSC) concept. System output constraints are addressed by employing an appropriate barrier Lyapunov function. Adaptive fuzzy disturbance observers are constructed to practically deal with time-varying unmatched but bounded disturbances. It is verified via Lyapunov stability analysis and simulation experiments that all closed-loop signals remain bounded, the output tracking error practically converges in finite time to a tiny but adjustable neighborhood around the origin, and the system output stays within its required time-varying bounds.