Robust Output Feedback Stabilization of MIMO Invertible Nonlinear Systems With Output-Dependent Multipliers

This article studies the robust output feedback stabilization problem for multi-input-multi-output (MIMO) invertible nonlinear systems with output-dependent multipliers. An 'ideal' state feedback is first designed under certain mild assumptions. Then, a set of extended low-power high-gain observers is systematically designed, providing a complete estimation of the 'ideal' feedback law. This yields a robust output feedback stabilizer such that the origin of the closed-loop system is semiglobally asymptotically stable, while improving the numerical implementation with the power of high-gain parameters up to 2.