L1 adaptive controller for a class of systems with unknown nonlinearities

This paper presents an extension of the L₁ adaptive controller to a class of general nonlinear uncertain systems, nonaffine in control. The control signal interacts with system states and time-varying uncertainties in an unknown nonlinear way. The adaptive controller ensures uniformly bounded transient for system´s both input and output signals simultaneously. The performance bounds can be systematically improved by increasing the adaptation rate. Simulation results verify the theoretical findings.