Abstract: During the detection of automobile chairs’ electric slides, the characteristic signals related to the comfort characteristic have been extracted from the vibration signal, and its power spectrum density is chosen as one of the criteria for quality control of products. Based on the demodulation of the second-order circulation statistics of cyclic spectrum density (CSD), the CSD slice chart of the vibration signal of the products is analyzed. And the characteristic modulation signals are obtained. As a result, the defect frequencies which effect the riding comfort are obtained according to their respective power, and the products quality can be well evaluated

Key words: vibration and wave, cyclic autocorrelation function, cyclic spectrum density (CSD), demodulation, electric slides, product quality control

摘要： 从汽车座椅电动滑轨产品检测得到的振动信号中提取影响产品舒适性的特征信号，并以其对应的功率密度作为产品质量评判的标准之一。利用二阶循环统计量循环谱密度函数的解调特性，对产品振动信号的循环谱密度函数切片图进行分析，得到隐含在其中的特征调制信号，并根据影响人体舒适感的频率范围找出缺陷频率点。依据缺陷频率点的功率密度，可以很好的评价产品的性能。

关键词: 振动与波, 循环自相关函数, 循环谱密度函数, 解调, 电动滑轨, 产品质量检测