Fault Diagnosis And Multi-Model Fault Tolerant Controller Design For A Multi-Vector Propeller Aerostat

With the increasing complexity of modem aircraft,the possibility of failure of aircraft components is greatly increased.Therefore,how to diagnose the failure of aircraft in real time and design the corresponding fault-tolerant controller has become a focus problem of modem flight control system design.Modern flight control system should have the following functions:real-time monitoring and identification of the possible faults of the system,and then adjusting the corresponding control strategy,so as to ensure the stability of the system under the fault conditions,and achieve feasible performance.In this paper,the typical faults of sensors and actuators of the multi-propeller combined aerostat are monitored in real time by principal component analysis(PCA).Contribution graph method is used to identify sensor faults and state observer method is used to identify actuators faults respectively.On the basis of fault diagnosis,multi-reference model tracking control method based on performance reduction is used to design controller.The stability and feasible performance are ensured by this controller.The main work and achievements of this paper are as follows.Principal Component Analysis(PCA)and Contribution Graph are combined to monitor and identify the typical faults of the sensor.The simulation results show that the method can effectively identify the drift faults,bias faults and impact faults of the sensor.Principal Component Analysis(PCA)and State Observer are combined to monitor and diagnose the actuator faults of the aerostat,and multiple propeller thrust efficiency faults can be identified at the same time.The simulation results are given.A multi-reference model tracking control method based on performance reduction is used to design the controller.Aiming at the faults of different efficiency loss of actuators,different reference models are designed,and then the control gain can be adjusted automatically under different faults.The results show that the designed fault diagnosis algorithm can diagnose sensor and actuator faults in real time,and a fault-tolerant controller is designed based on the diagnostic results to achieve feasible flight performance.At the same time,by using the reference model based on performance reduction,the problem of saturation of output amplitude of the controller can be avoided.