汽车发动机瞬时转速信号的小波分析

采用小波变换这一工具对瞬时转速信号进行处理。在介绍小波变换基本原理的基础上，对曲轴瞬时转速信号进行了多分辨率分析，即把转速信号分解为多个层次的细节部分和平滑部分。曲轴瞬时转速信号中的噪声被分解到了各层的细节部分，由剩余的平滑部分呆判断发动机的失火和检测各缸工作均匀性，从而为实现失火检测和各缸工作均匀性检测提供了一个新的信号处理方法。

Momentary Speed Analysis or Automotive Engines Using Wavelet

This paper presents a new methodwavelet transform. After a brief introduction to the principle of wavelet transform, the original speed signal isdecomposed into approximation components and detailcomponents at several levels. This decomposition processis called multi-scale analysis. After the decomposition,the noise in the speed signal is separated from the approximation components and stored in the detail components. From the approximation components, workingunevenness of each cylinder can be easily estimated, evenunder the high speed condition. Therefore, Wavelettransform paves a new way to process engine momentaryspeed.