A method for rapid and coarse alignment in large headings

Abstract

The invention relates to a coarse alignment method for serial inertial navigation, and particularly relates to a rapid coarse alignment method suitable for a large course for a serial inertial navigation system. The rapid coarse alignment method disclosed by the invention comprises the following steps of: measuring an east initial attitude angle at time zero; measuring a north initial attitude angle at time zero; constructing a transformation matrix from a carrier coordinate system to a platform intermediate coordinate system, and executing a serial inertial navigation update calculation under a condition of a static base; obtaining the accelerations fn(1),..., fn(m) at a series of time points in a navigation coordinate system; determining an intermediate speed parameter vn of coarse alignment under the condition of a static base at a time end of 60 s; calculating the trigonometric function value of a coarse course; and constructing a transformation matrix from the platform intermediate coordinate system n' to the navigation coordinate system n, and determining the initial attitude matrix of the large course. In the method disclosed by the invention, the step of course alignment for the large course can be finished only by performing a group of serial calculations, thus greatly shortening the time of course alignment in case of no increase of hardware cost, and providing a high accuracy for fine alignment in the next step.

Description

technical field [0001] The invention relates to a rough alignment method of a strapdown inertial navigation system, in particular to a fast rough alignment method suitable for large headings of a strapdown inertial navigation system. Background technique [0002] The main task of the initial alignment is to give the initial attitude matrix of the SINS. The initial alignment of SINS can generally be divided into two stages: coarse alignment and fine alignment. The main task of coarse alignment is to quickly estimate the rough value of the attitude, that is, to control the attitude error within a relatively small range, and create conditions for the next step of using a linear model for fine alignment. According to the requirements of the main task of coarse alignment, the requirement for accuracy is not very strict at this stage, but the rapidity of speed is what is required. Therefore, it is necessary to provide a coarse alignment method to quickly determine the rough init...

AI Technical Summary

Problems solved by technology

From the simulation results, it is effective to shorten the time of coarse alignment based on the multi-strapdown solution method, which reaches about 100s. Interval division, such as taking the heading angle of 60° as an example, divide it into 6 intervals, and use the center of the interval as the initial value of the heading angle to carry out 6 groups of strapdown calculations and Kalman filter calculations at the same time, which greatly increases the The amount of calculation, which requires the computing performance of the computer to be high

[0004] The rough alignment of strapdown inertial navigation has been described and explored above, but the requirements of rapidity and small amount of calculation for rough alignment have not been met at the same time. Therefore, it is innovative to study a coarse alignment method with small amount of calculation and fast and practical engineering value

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