振动信号趋势项提取方法研究

针对某车载武器振动位移测试中存在的严重趋势项干扰问题，提出了基于经验模态分解（Empirical Mode Decomposition，EMD）的信号处理方法.为有效提取趋势项，提出了一种新的趋势项判定方法.该方法根据振动信号相对时间轴对称的特点，通过比较各IMF分量与原始信号的均值判定该阶IMF分量是否为趋势项.模拟振动信号仿真证明了方法的有效性.最后对实测信号进行了EMD处理并最终重构了振动位移信号，与小波变换方法及一种定性的EMD趋势项判定方法进行了比较，结果表明提出的基于EMD的信号趋势项提取和判定方法有更大的优越性，有助于客观评价该武器性能.

Research on Vibration Signal Trend Extraction

A signal processing method based on empirical mode decomposition (EMD) is proposed,aiming at the serious interference problems that exist in the vibration displacement tests for the vehicle weapon.A new judgement criterion of determining the trend is presented for extracting the trend effectively.According to the symmetrical characteristics of the vibration signal relative to the time axis,the method determines whether the IMF component belongs to the trends by comparing the mean value between each order IMF component and the original signal.Effectiveness of the method is verified by the simulation vibration signal.The measured signals are processed by EMD,and the vibration displacement signal eventually is reconstructed.By comparing with wavelet transform method and a qualitative EMD trend determinant method,the results show that the trend extraction method based on EMD is effective and helpful to evaluate the performance of the weapon objectively.