A robust adaptive reconfigurable flight control scheme for accommodation of control effector failures

The authors present the proof of robustness of the newly developed Failure Detection and Identification (FDI) and Adaptive Reconfigurable Control (ARC) scheme for accommodation of control effector failures. The failures include lock-in-place and hard-over. The scheme is based on adaptive interacting multiple observers (AIMO) arising from the concept of multiple models, switching and tuning. The overall system consists of online FDI observers for all control effectors, plus one for the no-failure case, and corresponding adaptive reconfigurable controllers. It is shown that, in the case of control effector lock-in-place or hard-over and in the simultaneous presence of large sporadic disturbances, the scheme assures the boundedness of all signals in the system, guarantees asymptotic tracking, and ensures convergence of the failure-related parameter estimate to its true value. The scheme is tested on a linearized model of the Boeing's Tailless Advanced Fighter Aircraft (TAFA), augmented with position and rate limits on the control effectors, and resulted in an excellent overall response despite simultaneous presence of flight-critical failures and large external disturbances.