Adaptive and reconfigurable flight control using feed-forward action

Indirect adaptive control for reconfigurable flight control is advocated. Specifically, on-line static system identification using a moving window/batch estimation, is used. The ensuing linear regression is augmented with an intercept to address the effects of trim change associated with the occurrence of a control surface failure. Parameter estimate information is used to adjust the inner loop´s control gains and a command derived from the intercept estimate is fed forward to retrim the aircraft automatically. The tracking performance of this automatic retrimming method which uses system identification, surpasses the conventional approach of exclusively relying on integral action for automatic retrimming. The novel adaptive and reconfigurable flight control system successfully handles a horizontal tail control surface loss