Lie group filtering-based initial alignment method for strapdown inertial navigation

Abstract

The invention discloses a Lie group filtering-based initial alignment method for strapdown inertial navigation. A strapdown algorithm is described by adopting Lie group and Lie algebra, so that the problem of singular value and a normalized error in a quaternion solving process can be effectively avoided. A new system model is established by integral computation and geographical position information of inertial elements. Recursive estimation is directly performed on an SO(3) group by adopting a Lie group filter, so that the problem of nonlinearity of a quaternion model can be effectively solved, and rapid and accurate initial alignment can be realized. An attitude change of a carrier under swaying interference is reflected in real time, so that the initial alignment can still be rapidly and accurately realized independently of an error model of a system under a swaying condition, and the initial alignment under a swaying pedestal can be finished without fine alignment on the basis of rough alignment. The method is simple in computation and high in adaptability, can be used for a complex random system, and has broad application prospect in practical engineering, the alignment accuracy is ensured, and meanwhile, the alignment speed is increased.

Description

technical field [0001] The invention discloses a strapdown inertial navigation initial alignment method based on Lie group filtering, 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, and can provide complete motion information for the carrier all day and all weather. [0003] The early inertial navigation system was mainly based on platform inertial navigation. With...

AI Technical Summary

Problems solved by technology

[0006] The quaternion representation method makes up for the lack of Euler angles. There is no singularity problem in the calculation process, but there are constraints in the quaternion. When the quaternion is used to describe the attitude movement, it is difficult to satisfy the problems with its constraints

Moreover, the quaternion description method is complex in the calculation process, and calculation errors are unavoidable, resulting in deviations in attitude calculations

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