多凹点滤波器在LINS中的应用  

Multi-notch filter application in laser inertial navigation system

作　　者：李汉舟[1,2] 潘泉[1] 杨娜 张娟妮 邓麟 

机构地区：[1]西北工业大学自动化学院,西安710072 [2]航天科技集团第16研究所,西安710100

出　　处：《中国惯性技术学报》2015年第4期451-456,共6页Journal of Chinese Inertial Technology

基　　金：国家自然科学基金重点项目(61135001)

摘　　要：分析了激光捷联惯性导航系统中的激光陀螺频谱特性,指出激光捷联惯性导航系统中三个激光陀螺的抖动频率会互相干扰。提出一种多凹点有限冲击响应低通滤波器频域设计方法,通过指定三个抖动频率点幅值为小量,在幅频特性曲线上产生三个凹陷点。该滤波器采用标准滤波算法,同时实现了对激光捷联惯性导航系统三个激光陀螺的滤波和机抖信号的陷波。给出了一个24阶多凹点滤波器设计实例,幅频特性分析说明,由于三个陷波点的集中,该滤波器还可以在机抖频率可能存在的频段上,提供额外的80 d B以上的衰减,可防止激光陀螺抖动频率漂移后陷波性能下降。试验结果表明,多凹点滤波器输出数据波动幅度比原激光捷联惯性导航系统使用的滤波器结果减小5~8倍,三轴摇摆试验的导航精度也有一定提高。The power spectrum characteristics of ring laser gyros in laser inertial navigation system（LINS） are analyzed, which suggests that three laser gyros＇ dithering frequencies will interfere with each other in LINS. A novel low-pass finite impulse response（FIR） filter with three-notch is proposed to filter the dither frequencies of the ring laser gyros. A multi-notch FIR filter is designed with frequency-domain design method by specifying the amplitude of three dithering frequencies to be a small quantity. Three notches are produced naturally in the FIR amplitude frequency characteristic curve. The filter adopts a standard FIR algorithm. Meanwhile, the low-pass filter for the three laser gyros＇ signal in LINS and notching for the dithered signal are realized. A 24-order multi-notch FIR filter is given as an example to process the data of a high-precision LINS. The amplitude-frequency characteristic analysis shows that the new filter provides extra attenuation by at least 80 d B in the possible dithering frequency band due to three notch points concentrated. The extra decay can effectively prevent the filter performance degradation due to the laser gyro＇s dithering frequencies drift. Experiments suggest that the data oscillation of the output from the new filter is decreased by 5~8 times compared with that of the old filter in the LINS. Furthermore, the three-axis wobbling test results show that the navigation precision can also be improved.

关 键 词：激光捷联惯性导航系统 激光陀螺 有限冲击响应滤波器 陷波 抖动频率 

分 类 号：U666.1[交通运输工程—船舶及航道工程]