Patent ID: 7853338

Claim:
An apparatus receiving a command signal y c to control a plant, the plant generating a plant output signal y that is a function of states of the plant, the apparatus comprising: a nominal controller for generating a nominal control signal u ec to control the plant based upon a plant model of the plant in response to a difference between at least the command signal y c and the plant output signal y; a reference controller for generating a reference control signal u ec (y m ) based upon a same plant model as the nominal controller in response to a difference between at least the command signal y c and a reference model output signal y m ; a plant model comprising an approximation of the plant and operatively coupled to receive the reference control signal u ec (y m ) from the reference controller and produce the reference model output signal y m ; a first combining unit operatively coupled to the plant and the plant model to find a difference between at least the plant output signal y and the reference model output signal y m to generate the plant output error signal {tilde over (y)}; an adaptive control unit operatively coupled to the first combining unit to receive the plant output error signal {tilde over (y)} and generate an adaptive control signal u ad based on the plant output error signal {tilde over (y)}; and a second combining unit operatively coupled to the adaptive control unit, the nominal controller and the plant to augment the nominal control signal u ec based on the adaptive control signal u ad .