Research on Fault-Tolerant Control of Aeroengine Nozzle Actuator

To address the loss of closed-loop nozzle control caused by failures in the nozzle throat angle sensor or the nozzle oil separator valve displacement sensor, a fault-tolerant control method for the aeroengine nozzle actuator based on dynamic control loop reconfiguration is proposed. When either sensor fails, the control structure is reconfigured by removing the corresponding servo loop that can no longer form a closed loop, thereby preserving the remaining effective control loops and maintaining nozzle controllability. The proposed method is validated through full-digital simulation, hardware-in-the-loop simulation, and bench testing. The results show that the method ensures the stable operation of the digital control system over the representative operating conditions across the flight envelope and maintains satisfactory steady-state and dynamic performance under sensor fault conditions. The steady-state fluctuations before and after faults remain comparable. Although transient overshoot and droop increase after fault occurrence, the deterioration is limited: the fan speed overshoot and droop remain within 3% and 4%, respectively, while those of the compressor speed remain within 1% and 3%, respectively. Overall, the proposed method mitigates post-fault performance degradation and improves the fault tolerance of the nozzle control system. These results show that the method provides a feasible technical approach for enhancing the reliability of aeroengine digital control systems.