Tuning Function-Based Adaptive Observer Backstepping Control for Parametric Output Feedback Systems

An nonlinear adaptive observer based on filters is designed for parametric output feedback systems, and based on this observer using observer backstepping method to design an adaptive controller. Tuning function method is used to avoid over-parametrization. Nonlinear damping is used to counteract the destabilizing effect of the observation errors. This scheme is different from the K-filter scheme and MT-filter scheme. We use the estimated states as the virtual control other than the output signals of the filters. The closed-loop system can be guaranteed all the signals involved globally uniformly bounded and the convergence of the tracking error