Aircraft Nonlinear AFTC based on Geometric Approach and Singular Perturbations in case of actuator and sensor faults

The Singular Perturbation (SP) theory seems to be a very advantageous framework to describe the longitudinal aircraft dynamic and for designing advanced Flight Controls. In this paper, thanks to SP theory, a novel Active Fault Tolerant Flight Control (AFTFC) has been developed in order to accommodate faults occurring on all actuators and sensors. The proposed AFTFC is composed by two main subsystems: a Fault Detection and Diagnosis (FDD) module, that provides fault estimation, and a Controller that, exploiting this estimation, tracks a reference trajectory, even in presence of fault. The jointly use of the NonLinear Geometric Approach and SP allows the solution of the FDD problem, otherwise not possible for the considered fault scenario. The effectiveness of the proposed AFTFC system is highlighted by extended simulations exploiting a detailed wide–body aircraft flight simulator.