Marine fiber optic gyroscope attitude heading reference system mooring extractive alignment method under the large heading errors

Abstract

The invention provides an accurate aligning method for berthing ship-used fiber peg-top strapdown attitude system in large misalignment angle. For a ship-used fiber peg-top strapdown attitude system in berthing condition, on the base that coarse alignment is performed according to collected information of the output of peg-top and the acceleration output (because of very big longitudinal vibration, transverse vibration, vertical vibration), a converting array between a carrier coordinate system and a calculating geography coordinate system is built to determine quaternion error; a kalman filtering equation using the quaternion error and the speed error as state variables and a measuring equation using speed error as measuring variable are built; by the quaternion error and the quaternion corresponding to the attitude array in first time, the quaternion corresponding to converting array between the carrier coordinate system and an inertia system is figured out for original aligning. In the invention, the system equation is still linear for large misalignment angle, relatively mature kalman filtering is used for filtering estimating, a high accuracy and a good reliability are attained; the invention is not sensitive to the three vibrations in ship berthing condition, thus a high aligning accuracy is got.

Description

(1) Technical field [0001] The invention relates to a measurement method, in particular to an alignment technology of a strapdown heading attitude system, and in particular to a mooring fine alignment method of a marine optical fiber gyro strapdown heading attitude system. (2) Background technology [0002] The strapdown attitude system is a navigation system that connects the inertial instrument to the carrier and uses a computer to complete the navigation platform function. Compared with the platform inertial navigation system, it has the advantages of small size, light weight, low cost, high reliability, and easy maintenance. advantages, so it has been more and more widely used. And its navigation accuracy largely depends on the accuracy of the initial alignment. The initial alignment is generally divided into two stages: rough alignment and fine alignment, where the attitude matrix is ​​given by the rough alignment and the misalignment angle is generally not too large, ...

AI Technical Summary

Problems solved by technology

The coarse alignment method directly uses the measured value of the accelerometer, but the ship is affected by surge, sway, and heave under mooring conditions, and the accelerometer information is polluted, so the alignment effect is often not very good, and the misalignment Larger angle system error presents more serious nonlinear characteristics

However, the traditional fine alignment method (such as the second-order leveling method) often cannot meet the alignment accuracy requirements due to the influence of surge, sway, heave and large misalignment angle under mooring conditions.

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