Initial Alignment of the Strapdown INS on the Vibrating Base

摘要

The problem of the strapdown INS' initial alignment, which base have small rectangular and angular vibrations respect to Earth, is considered. The similar problems take place at the initial alignment of strapdown INS on a car with working engine. If the amplitudes of rectangular and angular vibration are accordingly 5 mm and I arc minute, and the frequencies are equal 10 Hz, the output signals of strapdown INS' sensors exceed levels of useful signals in 2 times for acceleration and in 250 times for angular velocity. Initial alignment algorithms are divided for two parts: the rough algorithms, which use the accumulated sums of quasi coordinates arriving from accelerometers and angular velocity sensors (AVS); the fine algorithms, which include attitude-navigation algorithms and the asymptotic filters with constant gain coefficients. Finally, the results of the mathematical simulation are reported. It is shown, that the initial alignment algorithms can supply accuracy of the alignment in 3 arc minute for 5/10 minutes depends on vibration parameters.