L1 adaptive controller for a class of systems with unknown nonlinearities

This paper presents an extension of the L
₁
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.