Method for improving precision of fiber optic gyroscope (FOG) north-seeker

Abstract

The invention discloses a method for improving precision of a fiber optic gyroscope (FOG) north-seeker, comprising the following steps of: calibrating the north-seeker to obtain calibration factor and installation error of FOG and an accelerometer; carrying out four-position data acquisition and pretreatment based on system installation error calibration, and then calculating axial acceleration of a base system to obtain pitch angle and roll angle of the north-seeker; and calculating and determining axial angular velocity of the base system to finally obtain azimuth angle of the north-seeker. By the adoption of the method, north-seeking errors caused by rotating errors and rotating shaft orientation errors of an indexing mechanism are eliminated; north-seeking errors caused by installation errors of FOG and the accelerometer are eliminated; technological requirements of the north-seeker are reduced; there is no need to eliminate installation errors from the aspect of technology; it is unnecessary for the four positions rotated by the indexing mechanism to be strictly orthogonal each other; and the north-seeking precision of the FOG north-seeker under all-attitude state is improved.

Description

technical field [0001] The invention relates to the fields of navigation, guidance and control, in particular to a method for improving the precision of an optical fiber gyro north finder. Background technique [0002] In the fields of military applications and engineering surveys, such as missile launch systems, ground radar systems, tunnel construction, etc., there is a demand for autonomous orientation. As a precision inertial measurement instrument, the gyro north finder plays a vital role in precise orientation, improving the precision of military systems and engineering efficiency. [0003] Fiber optic gyroscope is a kind of all-solid-state gyroscope, which has the characteristics of stable impact resistance, short start-up time, wide temperature range, small size, light weight, low power consumption, etc. It has very obvious advantages over mechanical gyroscopes. Therefore, the north finder using the fiber optic gyroscope has a higher degree of miniaturization, lower...

AI Technical Summary

Problems solved by technology

[0015] It can be seen that the traditional method has the following defects: (1) It cannot completely eliminate the rotation angle error and the rotation axis azimuth error of the indexing mechanism

(3) The components and mechanisms of the north finder are required to be processed with high precision, but the sensitive axis of the fiber optic gyroscope is a virtual axis, and it is difficult to ensure the misalignment angle of the sensitive axis through the process, so it is difficult to ensure its parallelism with the sensitive axis of the accelerometer

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