爆炸加速度信号重构速度和位移方法研究

RESEARCH ON RECONSTRUCTION VELOCITY AND DISPLACEMENT FROM EXPLOSION ACCELERATION SIGNAL METHOD

  • 摘要: 针对爆炸试验测试的加速度信号存在误差趋势项导致积分后速度和位移失真的问题,系统研究了最小二乘拟合、小波分解和EEMD(集成经验模态分解)分别去除爆炸加速度的趋势项中的应用,并积分重构了速度和位移,研究表明:最小二乘法的拟合阶数、小波分解法的分解层数和EEMD法的白噪声标准差对重构的速度和位移幅值有较大的影响;提出了使用频谱偏差指数s2和均偏差指数S2评价趋势项修正结果的方法,可以通过偏差s2频率分布与积分时程特征的联合分析选择合适的阶数、分解层数和白噪声标准差,精准去除信号中的趋势项。通过与爆炸试验结果的比对,证明3种方法均能还原爆炸冲击作用下的运动趋势和残余位移特征,其中小波分解法具有一定的优势。

     

    Abstract: Aiming at the problem of velocity and displacement distortion after integration caused by error trend term in acceleration signal tested in explosion test, the velocity and displacement after integration were reconstructed by removing the trend term of explosion acceleration based on least square fitting, wavelet decomposition and EEMD (Ensemble Empirical Mode Decomposition). The research shows that: The fitting order of the least square method, the number of decomposition layers of the wavelet decomposition method and, the standard deviation of the white noise of EEMD method have great influence on the reconstruction speed and displacement amplitude. A new method is proposed to evaluate the trend term correction results by using the spectral deviation index s2 and the mean deviation index S2, and the appropriate order, decomposition level and white noise standard deviation can be selected through the joint analysis of the frequency distribution and integral time history characteristics of the deviation S2 to accurately remove the trend term in the signal. Compared with the explosion test results, it is proved that the three methods can restore the motion trend and residual displacement characteristics under the impact of explosion, and the wavelet decomposition method has some advantages.

     

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