小型涡喷发动机故障分析及控制系统改进

针对小型高速无人机配装的小型涡喷发动机发生的空中停车故障,以发动机转速异常为顶层事件,以导致顶层事件发生的全部可能性为基本事件建立故障树,结合发动机控制原理及对遥测数据进行仔细分析,确认发动机转速采集信道出现问题导致发动机控制系统进入边界控制,而边界条件设置不合理导致发动机工作在超速超温状态,最终失效.通过采取增加转速采集备份信道、改进ECU控制保护算法、修改ECU档位油门限幅等措施有效地排除了此类故障,提高了发动机工作的可靠性.

Failure Analysis and Control System Improvement of Small Turbojet Engine

For small turbojet engine shutdown failure in flight of small high-speed unmanned air vehicle, a fault tree was established based on the abnormal engine speed as the top event, taking all the possibilities which caused the top event as the basic event. The telemetry data were carefully analyzed with the principle of engine control. Acquisition channel of engine speed caused a trouble, it may lead to engine control system into the boundary control problem. However, unreasonable boundary condition made engine work under the over speed and over temperature state, eventually lead to the failure. Increasing backup channel of engine speed acquisition, improving the ECU control protection algorithm and modifying the ECU limitation of gear throttle can resolve this failure effectively, and can improve the reliability of the engine.