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中文核心期刊

运动声源多普勒畸变信号自适应校正方法

An adaptive correction method for Doppler distorted signal of moving sound source

  • 摘要: 提出了一种自适应多普勒畸变校正方法,以声源移动速度v、初始时刻麦克风与声源横向距离x两个运动学参数为优化变量,以最大化重采样信号的频域统计指标为优化目标,通过参数寻优进行vx的估计,通过幅值还原和时域插值拟合进行畸变校正。仿真分析结果表明,频谱峭度、频谱偏度、频谱脉冲因子和频谱峰值因子4种统计指标均能准确识别运动学参数,且频谱峭度的抗噪能力最好,临界信噪比达到-3.1dB。实验分析结果表明,列车故障轴承多普勒畸变声音信号校正后,包络谱故障频率成分及其倍频成分清晰准确,说明多普勒畸变得到有效校正。该方法可基于信号本身实现多普勒畸变信号时频结构的全面校正。

     

    Abstract: An adaptive Doppler distortion correction method is proposed. The two kinematics parameters, the sound source moving speed v and the the distance, x, between the microphone and the sound source at the initial moment, are used as the optimization variables, and the maximized frequency domain statistical index of the resampled signal is the optimization objective. The values of v and x are estimated through parameter optimization, and the distortion correction is performed through amplitude restoration and time-domain interpolation fitting. The simulation analysis results show that the four statistical indicators including the spectral kurtosis, spectral skewness, spectral impulse factor and spectral crest factor can accurately identify the kinematic parameters. The spectral kurtosis has the best anti-noise ability, and the critical signal-to-noise ratio reaches -3.1 dB. The experimental analysis results show that after the Doppler distorted sound signal of the faulty train bearing is corrected, the fault frequency component and higher harmonic components of the envelope spectrum are clear and accurate, indicating that the Doppler distortion is well corrected. This method can realize the comprehensive correction of the time-frequency structure of the Doppler distorted signal based on the signal itself.

     

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