Self-adaptive initial alignment method of combined inertial navigation system suitable for satellite communication in motion

Abstract

The invention relates to a self-adaptive initial alignment method of a combined inertial navigation system suitable for satellite communication in motion. The method comprises the following steps: (1)defining coordinate systems; (2) obtaining a conversion matrix from an inertial coordinate system to a navigation coordinate system; (3) obtaining a conversion matrix from a base relation coordinatesystem to the inertial coordinate system; (4) obtaining a conversion matrix from a carrier coordinate system to a base relation coordinate system; (5) calculating an average value of conversion matrices from multiple carrier coordinate systems to the base relation coordinate system; (6) calculating an error of a conversion matrix from the base relation coordinate system to the inertial coordinatesystem; (7) setting a threshold value and comparing the threshold value with the error; and (8) obtaining a conversion matrix from the carrier coordinate system to a navigation coordinate system according to the steps (2), (3) and (4) so as to realize initial alignment of a carrier. The method makes use of the characteristic of slow change of a projection of a gravity acceleration on a base inertial system, and merges judgments of dynamic characteristics to adapt to satellite communications in motion in different states.

Description

technical field [0001] The invention relates to the field of combined attitude measurement, and mainly relates to an adaptive initial alignment method of a combined inertial navigation system suitable for communication in motion. Background technique [0002] In the prior art, the coarse alignment of the inertial navigation system in motion is generally implemented in two ways, one is analytical coarse alignment, and the other is swing dynamic alignment. [0003] Analytical coarse alignment requires that the carrier must be completely still. In the case of a vehicle, it is even required to turn off the engine and avoid people from walking. Initial alignment is performed, therefore, analytical coarse alignment is not suitable for communication-in-motion. [0004] Swing dynamic alignment can meet the coarse alignment of communication in motion under dynamic conditions, but the alignment time of this method is long, and it takes at least 1-2 minutes to complete the coarse alig...

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Problems solved by technology

[0004] Swing dynamic alignment can meet the coarse alignment of communication in motion under dynamic conditions, but the alignment time of this method is long, and it takes at least 1-2 minutes to complete the coarse alignment with a certain accuracy, so it will prolong the initial alignment time of the inertial navigation system , unable to meet the rapidity requirements of users

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