High-gain-predictor-based output feedback control for time-delay nonlinear systems

This paper designs a high-gain predictor for output feedback control of nonlinear systems in the presence of input, output, and state delays. The high-gain predictor realizes the states appearing in the output feedback control in terms of predictive state, delayed state, and current state. The system includes internal and external dynamics, and the closed-loop system under state feedback is required to be asymptotically stable and locally exponentially stable. Positively invariant sets are found to verify boundedness, exponential stability, and performance recovery. In the simulation, a saturated sliding mode control is applied to demonstrate the performance recovery of the closed-loop system, and the fact that the high-gain-predictor parameter has a lower bound related to time delays.