RESEARCH ON APPLICATION OF WAVELET ANALYSIS IN NORTH-SEEKER SYSTEM USING DITHER LASER GYROSCOPE

摘要

The strapdown north-seeker designed in this paper consists of a dither laser gyroscope, two quartz flexible accelerometers and a high precision rotating mechanism. In the engineering application, there are a lot of random noises in the dither laser gyroscope signal, which reduce the precision of north-seeker. To solve this problem, the preprocessing method based on the wavelet threshold filtering is proposed. After selecting the wavelet basis and the proper level of wavelet decomposition, the laser gyroscope signal is preprocessed. Besides, the levelling rotating mechanism is not necessary in this north-seeker. Meanwhile, the constant drift of inertial components can be compensated by using the two-position method. Simulation experiment shows that the preprocessing method based on wavelet filtering used in this paper can effectively improves the precision of the north-seeker. The heading information precision is better than 5 arc min in the north-seeker, which can give out the heading information in 300 seconds. By using the preprocessed dither laser gyroscope signal based on the wavelet analysis method, the strapdown north-seeker system could provide some references in the engineering application.