Optic fiber gyroscope strapdown inertial navigation system two-position initial alignment method based on filtering

Abstract

The invention provides an initial alignment method of two positions of a strapdown inertial navigation system of an optical fiber gyro which is based on filtering and comprises the following steps: initial position parameters of a carrier is determined by external equipment; data output by the optical fiber gyro and a quartz accelerometer is collected; the collected data of the optical fiber gyro and the quartz accelerometer is processed; a course angle K1 of the carrier, optical fiber gyro drift Xix1 in the east direction on the b system of a carrier coordinate system, and optical fiber gyro drift Xiy1 in the north direction on the carrier coordinate system are estimated; the carrier is rotated from a first position to a second position around an azimuth axis; a course angle K2 of the carrier, optical fiber gyro drift Xiy1 in the east direction on the b system of the carrier coordinate system, and optical fiber gyro drift Xiy2 in the north direction on the carrier coordinate system are estimated; gyro drift Xix and Xiy of the optical fiber gyro on the carrier coordinate system are computed; successive starting error of the gyro is calibrated; a platform alignment falloff angle is estimated. The initial alignment method of two positions of the strapdown inertial navigation system of the optical fiber gyro can overcome the influence of the equivalent gyro drift in a geographical coordinate system on the estimation precision of the azimuth alignment falloff angle and improve the alignment precision.

Description

(1) Technical field [0001] The invention relates to a two-position measuring method, in particular to a two-position measuring method for initial attitude parameters of an optical fiber gyroscope strapdown inertial navigation system based on filtering technology. (2) Background technology [0002] The initial alignment error is the main measurement error source of the fiber optic gyro strapdown inertial navigation system. The influence of the initial alignment error on the system error is not only reflected in the attitude measurement output, but also in the velocity and position measurement output. The measurement accuracy of the initial attitude of the carrier relative to the navigation coordinate system directly affects the accuracy of the navigation parameters. Therefore, before the FOG strapdown inertial navigation system enters the navigation solution state, the initial alignment process must be completed first. [0003] According to the motion state of the base, the ...

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Problems solved by technology

[0007] The purpose of the present invention is to provide a filter-based fiber optic gyro that can solve the problem that the eastward drift of the fiber optic gyroscope in the geographic coordinate system cannot be observed when the carrier is in a static state, which makes it difficult to improve the observability of the azimuth misalignment angle. Two-position Initial Alignment Method for Strapdown Inertial Navigation System

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