基于FFT的航空发动机整机振动分量实时跟踪监视

Tracing and Monitoring for Aero-engine Harmonic Vibration Based on Fast Fourier Transform

依据DFT(离散傅立叶变换)、FFT(快速傅立叶变换)、加窗等数字信号处理理论,以及复指数函数的相关性质,并结合目前国内航空发动机整机振动信号处理现状,提出了基于FFT的航空发动机整机振动分量跟踪监视方法。该方法首先将时域加速度振动信号分解为多个简谐振动合成结果,然后根据系统输入的转子转速信号,跟踪计算转子基频激起的简谐振动幅值,达到实时跟踪航空发动机整机振动分量的目的。还对该方法的系统误差进行了分析,指出了保证该方法测量准确度需注意的问题。理论分析和实测数据验证表明,该方法理论充分,且具有很好的实用性。

According to Discrete Fourier Transform （DFT）, Fast Fourier Transform （FFT）, window digital signal processing algorithms and complex exponent characteristics, a method of tracing and monitoring for aero-engine harmonic vibration is presented based on FFT. After having decomposed the aceeleration vi- bration signal as sum of several harmonic vibration, this method traces the amplitude of single-frequency vibration spurred by a rotor to implement the aim of tracing and monitoring aero-engine vibration. System error of the method is also analyzed, and some problems affecting the exactness are emphasized too. The theoretical analysis and test data show that the theory used for this method is powerful and practical ap- plication of this method is very good.