Gyro information-introduced double-position strapdown inertial navigation system initial alignment method

Abstract

A gyro information-introduced double-position strapdown inertial navigation system initial alignment method contains the following steps of: establishing an initial alignment state equation of a strapdown inertial navigation system; establishing a gyro information-introduced initial aligning measurement equation of the strapdown inertial navigation system; constructing a Kalman filter used for the initial alignment of the strapdown inertial navigation system; acquiring strapdown inertial navigation system information and completing initial alignment filtering of a first position; and acquiring strapdown inertial navigation system information and completing initial alignment filtering of a second position. The invention brings forward the gyro information-introduced double-position strapdown inertial navigation system initial alignment method. According to the method, based on the strapdown inertial navigation system double-position aligning method, equivalent east-facing gyro information is introduced into an initial aligning observation equation, so as to realize rapid estimation of random literal errors of an inertial device and realize rapid alignment of an azimuth angle. The final alignment precision is similar to the precision of a conventional double-position alignment method. The alignment time in the invention is far lower than that of the conventional double-position alignment method.

Description

Technical field [0001] The invention belongs to the technical field of inertial navigation, is an initial alignment method for strapdown inertial navigation systems, and is suitable for autonomous initial alignment before strapdown inertial navigation systems work. Background technique [0002] The task of initial alignment of strapdown inertial navigation system is to obtain the initial attitude matrix of strapdown inertial navigation system. According to the initial alignment process of the strapdown inertial navigation system, the initial alignment can be divided into two stages: coarse alignment and fine alignment. Analytical coarse alignment is the most commonly used autonomous coarse alignment method. It uses the transformation relationship between the earth’s rotation angular velocity and gravitational acceleration on the navigation system and the carrier coordinate system to calculate the initial attitude matrix; on the basis of coarse alignment, a small Strapdown inerti...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem of improving the alignment accuracy and prolonging the initial alignment time in the conventional two-position initial alignment method, the present invention proposes a two-position strapdown inertial navigation system initial alignment method that introduces gyro information

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