在频域分析中，包络谱分析是一种十分有效的信号处理手段。利用包络谱分析能够准确得出故障频率，能够直观判断故障类型。本文件将包络谱分析直接做成了一个子VI，方便信号处理程序直接调用。(In frequency domain analysis, envelope spectrum analysis is a very effective signal processing method. The fault frequency can be accurately obtained by using e