Strapdown inertial navigation system (SINS) swinging base self-aligning method based on Lie group optimal estimation

Abstract

The invention discloses a strapdown inertial navigation system (SINS) swinging base self-aligning method based on Lie group optimal estimation. Lie group description is adopted instead of traditionalquaternion description to realize the calculation of SINS attitude transformation; a linear initial self-aligning filtering model based on the Lie group description is established by using a Lie groupdifferential equation; and a Lie group optimal estimation method is designed to determine an initial attitude matrix required by navigation. According to the method, the optimal estimation is directly performed on the initial attitude matrix by a Lie group optimal estimation algorithm, so that the initial attitude estimation problem is transformed into the optimal estimation problem of a SO(3) group; one-step direct self-alignment of the SINS is realized; the aligning time is shortened greatly; the problems of non-uniqueness and non-linearity generated by the traditional quaternion description of the initial attitude matrix are solved; the alignment accuracy is improved effectively; and the problem that the orthogonality of a rotation matrix cannot be ensured due to the additivity error and the calculation error in a Lie group filtering method is solved. The method has practical value in the practical engineering.

Description

technical field [0001] The invention discloses a self-alignment method for a shaking base of a SINS strapdown inertial navigation system based on Lie group optimal estimation, and belongs to the technical field of navigation methods and applications. Background technique [0002] The so-called navigation is the process of correctly guiding the carrier along the predetermined route with the required accuracy and within the specified time to guide the carrier to the destination. The inertial navigation system calculates various navigation parameters of the carrier based on the output of its own sensors and based on Newton's second law. It is an autonomous navigation system that does not rely on external information and does not radiate any energy to the outside world during work. It has good concealment and strong anti-interference, and can provide complete motion information for the carrier all day and all weather. [0003] The early inertial navigation system was mainly bas...

AI Technical Summary

Problems solved by technology

The purpose of the present invention is to deal with the problems existing in the self-alignment method of the existing rocking base: (1) the present invention describes the initial attitude matrix by Lie groups instead of quaternions, avoiding the non-uniqueness and non-uniqueness of traditional quaternion description methods Non-linear problem; (2) the present invention utilizes Lie group differential equation to set up the linear self-alignment filter model based on Lie group description, has realized the one-step direct self-alignment process of SINS, compares existing two-step alignment method, can Significantly shorten alignment time and improve alignment accuracy; (3) the SINS strapdown inertial navigation system shaking base self-alignment method based on Lie group optimal estimation adopted by the present invention can effectively avoid existing quaternion Kalman In the filtering method, the complex expression problem and a large number of calculation errors caused by the conversion of the quaternion to the attitude matrix can avoid the problem that the orthogonality of the rotation matrix cannot be guaranteed due to the additive error and calculation error in the Lie group filtering method

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