摘要
针对光纤陀螺捷联惯性导航系统在晃动基座条件下传感器的输出噪声增大,导致对准结果收敛过程振荡剧烈、对准时间长、对准精度低的问题,提出了一种小波实时预滤波方法,确定了最优的小波基和分解级数,采用滑动数据窗、对称周期拓展和软阈值函数处理相结合的方案实现对惯性仪表的实时降噪。实验证明,该小波预滤波方法可以有效抑制惯性仪表输出信号的高频噪声。在晃动基座条件下,航向角大约在精对准,50s后收敛,其1σ值为2.77′,且与预滤波前相比姿态角收敛过程更加平缓。
The noise of sensors increase when the fiber optic gyroscope strapdown inertial navigation system （FOG SINS） performed on a rocking base, it will cost FOG SINS much more time to accomplish the initial alignment, with a sharply oscillatory convergence process and a low precision. To solve this problem, a preprocessing method based on wavelet real-time filtering is presented combined with sliding data window, symmetry boundary expansion and soft threshold to realize the real-time noise reduction of inertial instruments. The optimal level of wavelet decomposition and basic-wavelet are determined. Test results show that the wavelet pre-filtering method proposed in this paper can restrain high-frequency noise of inertial instruments effectively. Under the condition of swaying base, it approximately takes 50s for heading angle to reach the ultimate precision, and the value of 1σ is 2. 77′, and compared with the case without pre filtering, the convergence of attitude angles is steadier.
作者
石利利
张志鑫
吴海仙
吉云飞
SHI Li-li;ZHANG Zhi-xin;WU Hai-xian;JI Yun-fei(Beijing Aerospace Times Optical-electronic Technology Co.,Ltd,Beijing 100094)
出处
《导航与控制》
2018年第5期72-77,共6页
Navigation and Control
关键词
小波预滤波
光纤惯导
初始对准
噪声抑制
MALLAT算法
wavelet pre-filtering
fiber optic inertial navigation system
initial alignment
noise suppression
Mallat algo-rithm
