SINS self-alignment and latitude calculation method based on apparent motion of gravity

Abstract

The invention discloses an SINS self-alignment and latitude calculation method based on apparent motion of gravity. The method comprises the following steps: (1) constructing vectors of the apparent motion of gravity according to measured values of a gyroscope and an accelerometer; (2) eliminating influences caused by random noises of instruments via a parameter identification and reconstruction method; (3) calculating the coordinate of a central point of a base circle of a cone of the apparent motion of gravity and the radius of the base circle according to the vectors of the apparent motion of gravity at three moments; (4) constructing the vector of a center axis of the cone and finishing initial alignment according to a vector calculation method; and (5) finishing the calculation of a latitude L according to geometrical relationships of all vectors in the cone.

Description

technical field [0001] The invention relates to a SINS initial alignment and latitude calculation method based on gravity apparent motion, which is suitable for initial alignment under the wireless movement and swing conditions of the carrier aircraft, and does not require any external reference information during the alignment process, and is During the calibration process, the latitude calculation can be completed, which belongs to the technical field of navigation algorithms. Background technique [0002] For the inertial navigation system based on the integral working method, the initial alignment is the premise and foundation of its work, and it is also one of the key and difficult technologies of INS. Specifically for SINS, the initial alignment refers to obtaining the attitude matrix between the carrier system b and the navigation system n. Among many SINS initial alignment methods, self-alignment technology has been widely researched and concerned because it does no...

AI Technical Summary

Problems solved by technology

[0003] However, the above methods all have the disadvantage of insufficient anti-interference ability when performing initial alignment on a shaking base

For example, on a shaking base, the alignment cannot be completed because the angular velocity of the earth's rotation is completely submerged in the gyro noise

[0004] In addition, the above methods all need to use external position information during the initial alignment process

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