Discrete time L1 adaptive control for systems with time-varying parameters and disturbances

An extension to the L
1
adaptive control theory in a discrete-time framework is proposed. The extension addresses discrete-time systems with unknown time varying parameters, which include input disturbances, unknown input gain and system uncertainties. Sufficient stability conditions and performance bounds are derived. The proposed structure is applied to Rohrs' example to illustrate its stability and robustness features.