飞机座舱密封系统的气体泄漏信号检测

Detection of gas leakage signals in aircraft cockpit sealing system

飞机座舱密封系统是高空飞行中保障乘员生命安全的重要气密系统,需要定期或应急开展气体泄漏检测工作。传统检测方式错检、漏检率高,噪声环境复杂,难以实现定量检测并准确辨识气体泄漏信号。基于此,利用超声检测原理和座舱密封系统气体泄漏的小孔泄漏特征,根据气体泄漏孔处超声信号声压、声强与气体泄漏量之间的对应关系,推导得到座舱密封系统气体泄漏定量检测模型;针对强背景噪声环境下气体泄漏信号的检测需求,提出了改进的混沌Duffing振子方程,通过混沌阈值与噪声标准差、最大Lyapunov指数、系统相轨迹状态变化对比分析,以及开展飞机座舱气体泄漏检测实例分析,验证了该方法更适用于飞机座舱密封系统的气体泄漏信号辨识。

Cockpit sealing system of aircraft is an important air-tight system to ensure safety of crew in high-altitude flight,which should be carried out regularly or emergency quantitative detection of gas leakage.Because of high error and leakage detection rate and complex noise environment,it is difficult to realize quantitative detection and accurately identify gas leakage signal.Based on principle of ultrasonic detection and characteristics of small hole leakage of cockpit sealing system,according to corresponding relationship between sound pressure,sound intensity of ultrasonic signals and gas leakage at gas leakage hole,quantitative detection model of cockpit sealing system was derived.An improved chaotic Duffing oscillator equation was proposed for detection of gas leakage signals in presence of strong background noise.By comparing chaotic threshold with standard deviation of noise and maximum Lyapunov index,and analyzing state change of system's phase trajectory,as welas developing aircraft cockpit gas leakage detection example analysis,this method was proved to be more suitable for identification of gas leakage signals of aircraft cockpit sealing system.