L1 Adaptive Output Feedback Controller for Systems with Time-varying Unknown Parameters and Bounded Disturbances

This paper presents an extension of the L₁ adaptive controller to output feedback for systems with time-varying unknown parameters and time-varying bounded disturbances. The adaptive controller ensures uniformly bounded transient and asymptotic tracking for system´s both signals, input and output, simultaneously. The performance bounds can be systematically improved by increasing the adaptation rate. Simulations verify the theoretical findings.