A robust adaptive controller with minimal modifications for discrete time varying systems

The robust adaptive controller presented requires a minimal set of assumptions from the controlled plant and minimal modifications on the basis of conventional adaptive control algorithms to guarantee global stability of the closed loop system in the presence of fast parasitics and bounded external disturbances without any restriction on signals in the closed loop system such as persistence of excitation. Also the controlled plant is allowed to have a reduced order system with slowly time varying parameters. Further, the robust adaptive controller can still retain the properties that earlier unmodified conventional adaptive controllers had when the controlled plant satisfies so-called ideal assumptions