自适应滤波技术在激光多普勒测速仪中的应用

摘要

Noise always exists in photoelectric signal detected by laser Doppler velocimcter (LDV). A new method of signal processing was proposed in order to eliminate the noise interference and enhance the measurement accuracy of LDV. The least mean square(LMS) adaptive filter technology was applied in the signal detection system of LDV. By processing the Doppler signal, we greatly minished the interference of noise. The simulation ari3 experiment results indicate that this technology effectively increases the signal to noise ratio(SNR) of Doppler signal, reduces.the system's demand for SNR of signal, and obviously improves the noiseproof ability, the sensibility,as well as the measurement accuracy of LDV system. This application creates conditions for the design of high accuracy LDV.%激光多普勒测速仪检测系统提取的光电信号中存在较大的噪声信号.为了消除这些噪声干扰,提高激光多普勒测速仪的测量精度,提出一种新的信号处理方法,将最小均方差自适应滤波技术应用于激光多普勒测量中,利用多普勒信号和噪声信号的统计特性,以最小均方误差估计为准则,最大程度地滤除噪声信号.阐述了最小均方差自适应滤波算法的基本原理,在MATLAB平台上将其应用于理想正弦信号进行仿真,并将其应用于实测多普勒信号的处理中.仿真和实验均表明,该技术可以有效抑制激光多普勒测量中的多频率噪声的干扰,大大提高多普勒信号的信噪比和测量精度,为设计高精度的激光多普勒测速仪创造了条件.