Adaptive Output Feedback Control for Uncertain Systems with Unknown Disturbance

In this paper, we present a new scheme to design adaptive controllers for both linear and nonlinear uncertain systems in the presence of unknown disturbances. The control design is achieved by introducing certain well defined functions and a new linkage term in the adaptive update law. For the design and implementation of the controller, no knowledge is assumed on the unknown system parameters and disturbances. It is shown that the proposed controller can guarantee global uniform ultimate boundedness. A bound for the truncated L₂ norm of the tracking error is obtained as a function of design parameters