Latitude Unknown Self-alignment Method of Strapdown Inertial Navigation System under Dynamic Interference Conditions

Abstract

A latitude unknown self-aligning method of a strapdown inertial navigation system under the dynamic interference condition includes the steps that firstly, a geometrical analytic formula is built by means of the characteristic that the projection of gravity acceleration is unchanged in an inertial coordinate system, the gravity acceleration is subjected to integration to obtain speed information, and the latitude value of the position where a carrier is located is calculated according to the speed information; secondly, on the basis of the double-vector altitude determination principle and by means of the characteristic that the gravity acceleration of an inertial system includes north orientation information, rough solution of an initial attitude matrix under the inertial system is achieved; finally, on the basis that coarse alignment is finished, a precise alignment error model under the latitude unknown dynamic interference condition is built according to a speed error equation, a misalignment angle equation and a latitude error equation, the latitude error angle and the misalignment angle of the carrier are calculated by means of the self-adaptive filtering method based on information, the latitude value is compensated with the latitude error angle, the strapdown altitude matrix is corrected according to the misalignment angle, and high-precision quick self-aligning of the strapdown inertial navigation system is achieved.

Description

technical field [0001] The invention provides a latitude-unknown self-alignment method of a strapdown inertial navigation system under dynamic interference conditions, which involves the calculation of the latitude information of the position of the carrier under the shaking base, the solution of the rough initial attitude matrix under the inertial system, and the fine alignment The establishment of the quasi-state space model, the calculation of the latitude error angle and the carrier misalignment angle by the innovation-based adaptive filtering method, the compensation of the latitude error angle to the latitude value, and the correction of the strapdown attitude matrix by the misalignment angle. The present invention is suitable for the strapdown inertial navigation self-alignment process of the carrier in situations where the posture information is constantly changing due to external interference and does not provide accurate positioning information, such as in the depths ...

AI Technical Summary

Problems solved by technology

However, in an actual system, the system often becomes a random system due to various random factors. Approximate calculations are used in the calculation process, making it impossible to obtain an accurate system model, and it is difficult to know the system characteristics. In addition, considering the dynamic Interference conditions and unknown latitude lead to factors such as the latitude error term. There is too much system interference in the system, and the noise is not strictly white noise, resulting in poor Kalman filtering effect, and may even directly lead to Kalman filtering failure.

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