High Gain Adaptive Output Feedback Control of Nonlinear Systems with Some Uncertainties in Control Input Term

This paper deals with an adaptive output feedback controller design problem for nonlinear systems with higher order relative degree and some uncertainties in control input term. In this proposed method, the controlled system has a relative degree of one from the virtual filter signals as a control input to the controlled system output by introducing two virtual filters. The actual control input is designed for the virtual filter signals to be a high gain output feedback control through backstepping in the introduced filter dynamics. This proposed method is useful in the case where only the output signal is available.