A Method for Initial Alignment of Static Base of Rotary Strapdown Inertial Navigation System

Abstract

The invention belongs to the technical field of inertial navigation and provides an initial alignment method of a static base of a rotary type strap-down inertial navigation system to overcome the problems of the existing initial alignment method that the calculation amount is great, the convergence rate and the convergence precision are not ideal. The method adopts a low-order Kalman filtering state equation model and a corresponding self-alignment appearance observation obtaining method to effectively reduce the calculation amount in an alignment calculation process; and furthermore, the Kalman filtering performance is optimized through rotating an IMU (Initial Measurement Unit), so that the initial alignment performance of the static base of the inertial navigation system is improved.

Description

technical field [0001] The invention relates to an initial alignment method of a rotary strapdown inertial navigation system under the condition of a static base, and belongs to the technical field of inertial navigation. Background technique [0002] The initial alignment of the strapdown inertial navigation system is to determine the initial position, initial velocity and initial attitude angle of the carrier with a certain accuracy in a short period of time. The initial alignment of a strapdown inertial navigation system is usually divided into two stages: a coarse alignment stage and a fine alignment stage. In the coarse alignment stage, the direction cosine matrix from the carrier coordinate system to the navigation coordinate system is directly estimated according to the measured values ​​of the gravitational acceleration vector and the earth rotation angular rate vector. There is a deviation between the estimated value and the real value, but it should be small; fine ...

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Problems solved by technology

[0020] In order to overcome the problems of large amount of calculation, unsatisfactory convergence speed and unsatisfactory accuracy existing in the existing initial alignment method of velocity appearance measurement, the present invention proposes a method for initial alignment of static base of rotary strapdown inertial navigation system, which The method adopts the low-order Kalman filter state equation model and the corresponding self-alignment appearance measurement acquisition method to effectively reduce the calculation amount during the alignment calculation process. In addition, the Kalman filter performance is optimized by rotating the IMU (inertial measurement unit). Thus the initial alignment of the static base of the inertial navigation system is completed

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