Stable multiple model adaptive flight control for accommodation of a large class of control effector failures

We propose a new parametrization for the modeling of control effector failures in flight control applications. The failures include float, lock-in-place, hard-over, and loss of effectiveness. It is shown that the resulting representation leads naturally to a multiple model formulation of the corresponding control problem that can be solved using a multiple model adaptive reconfigurable control approach. We derive stable multiple model adaptive reconfigurable control algorithms for the most complex case when one of the effectors undergoes float, lock-in-place or hard-over failure, while all others lose effectiveness. The stability of the overall reconfigurable control system is demonstrated using the Lyapunov method and the separation between identification and control arising in the context of indirect adaptive control. The approach is illustrated through numerical simulations of the F-18 aircraft carrier landing manoeuvre.