实测一组机械系统的振动信号，记录采样频率、采样点数，估计该组振动信号的均值、均方值、方差、自相关函数和功率谱，其中功率谱估计对比频率平滑与分段平滑的效率，针对分段平滑、分析不同平滑次数对功率谱估计的影响-Found a mechanical vibration signal system, the recording sampling frequency, sampling points, the estimated mean the set of vibration signals mean square value, variance, autocorrelation function and power spectrum, wherein the power spectrum estimation and comparison of frequency smoothing piecewise smooth efficiency for piecewise smooth, analyze the impact of different smooth frequency power spectrum estimation