Semi-global Output Feedback Stabilization of Non-Minimum Phase Nonlinear Systems
It addresses a challenging control problem for nonlinear systems with non-minimum phase dynamics, but the approach is incremental and lacks concrete numerical results.
The paper solves output feedback stabilization for nonlinear systems with unstable zero dynamics, achieving semi-global stability and performance recovery using an extended high-gain observer and Kalman filter, demonstrated via simulation.
We solve the problem of output feedback stabilization of a class of nonlinear systems, which may have unstable zero dynamics. We allow for any globally stabilizing full state feedback control scheme to be used as long as it satisfies a particular ISS condition. We show semi-global stability of the origin of the closed-loop system and also the recovery of the performance of an auxiliary system using a full-order observer. This observer is based on the use of an extended high-gain observer to provide estimates of the output and its derivatives plus a signal used by an extended Kalman filter to provide estimates of the remaining states. Finally, we provide a simulation example that illustrates the design procedure.