Fast Initial Alignment Method for Sins Strapdown Inertial Navigation System Moving Base Based on Lie Group Description

Abstract

The invention discloses a fast initial alignment method for a moving base of a SINS strapdown inertial navigation system based on a Lie group description. The method uses the Lie group description instead of the traditional quaternion description to realize the calculation of the SINS attitude transformation, and uses the Lie group differential equation A linear initial alignment model is established, and the gyro drift is used as an augmented state quantity to establish an augmented initial alignment model, and then the Kalman filter algorithm in the form of a matrix is ​​used to realize the simultaneous estimation of the initial attitude matrix and the constant drift of the gyroscope. The invention uses the constant value drift of the gyroscope as the augmented quantity, and establishes a more accurate augmented linear alignment model compared with the traditional initial alignment model. The alignment method of the present invention can not only realize the one-step direct alignment of SINS, but also greatly shorten the alignment time, facilitate the compensation of errors in the strapdown solution process, effectively improve the alignment accuracy, and be more suitable for practical engineering applications .

Description

technical field [0001] The invention discloses a fast initial alignment method for a moving base of a SINS strapdown inertial navigation system described by Li Qun, which 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 performance, and can provide complete movement information for the carrier all day and all weather. [0003] The early inertial navigation system was mainl...

AI Technical Summary

Problems solved by technology

The purpose of the present invention is to deal with the problems existing in the existing moving base auxiliary alignment method: (1) the present invention describes the initial attitude matrix by Lie groups instead of quaternions, avoiding the non-uniqueness and non-uniqueness of the traditional quaternion description method Non-linear problem; (2) The present invention utilizes Lie group differential equations to establish a linear initial alignment model, and realizes a one-step direct self-alignment process of SINS, which can greatly shorten the alignment time compared with the existing two-step alignment method and improve the alignment accuracy; (3) the present invention uses the gyroscope constant value drift as an augmented state quantity to establish an augmented initial alignment model, which can effectively avoid the model error that the traditional initial alignment model does not consider the gyroscope constant value drift , at the same time, the constant value drift of the gyroscope can be estimated online synchronously, which is convenient for compensating the error in the strapdown solution process

Images