基于能量衰减比的双通道源数目估计方法

利用源信号到达两传感器间具有不同能量衰减比的特性,提出了一种新的源数估计方法,解决了因传感器数量不足而无法准确估计源信号数目的问题。首先,利用线性时频变换方法得到两观测信号在频域的能量分布,然后,计算能量散点图中对应角度上的能量总和;最后,通过峰值检测法实现源数目的自动检测。通过理论分析、仿真和实验,证明了该方法的有效性。本方法为盲源分离算法处理振动、噪声信号,提供了可靠的先验信息。

A Method Estimating the Number of Sources Based on Ratio of Energy Attenuation Between Two Sensors

The energy of a signal decreases with increasing propagation distance. When two sensors at different locations are used to collect the signals, each signal has its own energy attenuation ratio. In this paper, the energy attenuation feature of signals was employed to estimate the number of sources. For sources located in different frequency bands, the linear time-frequency transform method can be utilized to compute the energy corresponding to different frequency bands. Due to different energy attenuation ratios for each source, several cluster features will appear on the 2-D plot. Then, energy peak detection can be used to determine the number of sources. The proposed method can easily implement the experimental program and algorithm, and can be used to estimate an arbitrary number of sources. The effectiveness was verified by theoretical analysis, simulation data and experimental data, such as gearbox vibration signals, sound pressure signals and modal signals.