小波域中值滤波在激光陀螺信号处理中的应用

Application of median filter in wavelet domain in the signal processing of the laser gyro

各种随机噪声是导致激光陀螺产生误差的主要因素,且其性质特殊,很难用传统的滤波方法去除。为了减小激光陀螺的随机误差,提高测量精度,提出了小波域的中值滤波器滤波方法,对激光陀螺零漂数据进行了滤波,并采用Allan方差法对滤波效果进行了定量分析。结果表明,此方法的滤波效果优于中值滤波和小波软阈值滤波效果,能有效地减小激光陀螺零漂信号中的角度随机游走、角速度随机游走、速率斜坡、零偏不稳定性和量化噪声,提高激光陀螺零漂输出的稳定性。

The various random noises in laser gyro are the main factor affecting the accuracy. In accordance with the property of its noise, traditional filtering methods have many shortages. In order to decrease the random error and improve the measuring precision of laser gyro, a median filter method in wavelet domain is presented to denoise a set of zero drift signal of laser gyro, and the method of Allan variance is used to analyze the filtering result quantitatively. The result shows that the filtering algorithm can produce the better filtering effect than median filter and wavelet soft threshold denoising, decrease the angle random walk, rate random walk, rate ramp, the bias instability and quantization noise, and improve the stability of laser gyro drift output.