Patent ID: 7277764

Claim:
An apparatus receiving a commanded output signal y c to control a plant, the apparatus having a nominal controller implementing a plant model to control a plant to generate plant output signal y that is a function of all states of the plant, at least one of the plant states being unavailable, the nominal controller generating a nominal controller signal u ec (y), the apparatus comprising: a reference model unit generating a plant model output signal y m based on the commanded output signal y c , using a reference controller identical to the nominal controller, and a plant model identical to that upon which the nominal controller was based; a first combining unit coupled to receive and difference the plant output signal y and the plant model output signal y m to generate the plant output error signal {tilde over (y)}; an adaptive control unit coupled to receive the plant output error signal {tilde over (y)}, and comprising an error observer to generate an observed error signal Ê that estimates errors in all states of the plant, including those plate states that are unavailable, the adaptive control unit further comprising a neural network having connection weights M, N updated based on the observed error signal Ê, the neural network receiving a plant control signal u and the plant output signal y as inputs, and generating a neural network control signal u NN based on the plant control signal u, the plant output signal y, and the connection weights M, N, the adaptive control unit outputting an adaptive control signal u ad based on the neural network control signal u NN ; and a second combining unit coupled to receive the nominal controller signal u ec (y) and the adaptive control signal u ad , and generating the plant control signal u to control the plant based on the nominal controller signal u ec (y) and the adaptive control signal u ad .