Fuzzy logic aided fault-tolerant control applied to transport aircraft subject to actuator stuck failures

Failure to counteract in-flight actuator stuck failures within a limited amount of time can result in catastrophic consequences. Aircraft safety is also undermined when fault-tolerant control (FTC) systems are designed based on inaccurate diagnostic results. This paper presents an FTC scheme for transport aircraft subject to actuator stuck failures, which is integrated with fuzzy logic system (FLS), real finite-time sliding mode control (RFTSMC), and least squares control allocation (LSCA) techniques. First, the term, including the stuck information, is obtained by resorting to an FLS. The norm of the weight matrix is adopted in the FLS estimation, such that the amount of the adaptive parameters is independent of the number of FLS rules. Following this, a virtual fuzzy logic aided FTC strategy is developed using RFTSMC, by which the actuator stuck failure is counteracted within finite time. Furthermore, an LSCA unit is capable of distributing the commands to the fault-free actuators, with explicit consideration of incorrectly identified values of actuator effectiveness indicators. Finally, simulation studies of a nonlinear Boeing 747 longitudinal model are performed to validate the effectiveness of the proposed scheme.