离散余弦包络分析法在列车轮对踏面损伤检测中的应用

列车轮对踏面损伤是危及列车运行安全的重要因素，其损伤程度的实时监测与诊断是高速重载列车需要解决的关键问题之一。探讨了应用离散余弦变换的方法提取列车轮对踏面损伤的特征信息，即首先采用小波基将踏面损伤振动信号变换到时间一尺度域，再对高频段的小波系数采用离散余弦变换进行包络分析。试验结果表明，该方法能快速、准确地检测出机车踏面的损伤，可有效地应用于列车轮对踏面故障的在线监测与诊断。

Application of Discrete Cosine Envelope Analysis in Detecting Scrape of Wheelset Surface

The discrete cosine transform is used to extract the character information of the wheelset scrape. The wavelet bases are adopted to transfer the scrape vibration signals into the time-dimension domain, then the discrete cosine transform is applied to envelope the high frequency wavelet coefficient. The experiment results indicate that the method can examine the condition of wheelset surface scrape quickly and precisely. It can be used effectively in the real-time detecting and diagnosing of wheelset surface.