A MA-AT Based Fault Diagnosis Method of Large Aircraft

Aiming at the typical faults of the electromechanical actuation system of a redundant aileron control surface of the large aircraft, this paper proposes a fault diagnosis method based on the combination of multi-agent and adaptive threshold (MA-AT) considering the redundant electromechanical actuation system-flight control system closed-loop, which tackles the difficult problem of the determination of the fault diagnosis threshold. Firstly, the composition of the electromechanical actuation system of large aircraft is analyzed and an accurate mathematical model of the electromechanical actuator with fault information of each component is established. Secondly, the homogeneous multi-agent model is established according to the information interaction among the redundant electromechanical actuators and the distributed relative output error vector is obtained. To minimize the estimation error, the gain matrix of the observer is solved by combining pole assignment and H-infinity performance multi-objective design method, and the design of fault diagnosis observer for redundant electromechanical actuation system is completed. Finally, combined with the flight quality requirements of large aircraft and the design of typical roll angle control mode control law, the signal threshold for fault diagnosis of the electromechanical actuation system is adaptively obtained from the influence of fault signal on the electromechanical actuator and the influence of electromechanical actuator performance parameters on the key state of the flight control system, which provides the judgment basis for fault isolation of electromechanical actuator.