高速列车转向架区气动噪声分离研究

提出了一种基于快速路径优化的自适应短时傅里叶变换时频分析方法，并将该方法用于行星齿轮箱的故障诊断。该时频分析方法通过使用快速路径优化获得瞬时频率变化规律，在短时傅里叶变换过程中自适应的改变时窗长度，从而获得更恰当的时频分辨率。针对行星齿轮箱运行状态不稳定的特点，通过使用笔者提出的时频分析方法可以有效地提取出行星齿轮箱的转速信息，利用参考转速对故障信号角度域重采样和阶次分析，从而实现变转速情况下的行星齿轮箱故障诊断。仿真分析表明，与传统短时傅里叶变换相比基于快速路径优化的自适应短时傅里叶变换得到的时频分布能量更加集中；试验分析证明了基于快速路径优化的自适应短时傅里叶变换方法在行星齿轮箱故障诊断中的有效性。

Study on Separation of Aerodynamic Noise from High Speed Train Bogies

This paper proposes an adaptive short-time Fourier transform (ASTFT) method based on fast path optimization (FPO). The proposed method is applied to the fault diagnosis of planetary gearbox. This method can estimate the instantaneous frequency from the time-frequency distribution. Thus, the time window size can be adaptively adjusted by considering the instantaneous frequency. According to the characteristics of the planetary box, this method can be used to effectively extract the speed information and resample the fault signal in angle domain from which we can get the fault orders of the planetary gearbox. The vibration analysis of a gearbox demonstrates its effectiveness for fault diagnosis.The performance of the proposed method in this research work is validated by both the simulated and experimental signals including a vibration signal. Compared with the STFT, the proposed method demonstrates its superb accuracy and perfection in characterizing the time-varying time-frequency features of the signal.