Error correction method for geomagnetic vector measurement system based on Lagrange multiplier method

Abstract

The invention relates to the field of magnetic measurement and, more particularly, to an error calibration method for a geomagnetic vector measurement system based on a Lagrange multiplier method. The error calibration method comprises the steps of (S1) selecting a calibration area, setting a non-magnetic platform at the center of the area, and measuring the total amount of the geomagnetic field above the non-magnetic platform with a proton magnetometer; (S2) encapsulating a geomagnetic vector measurement system in a non-magnetic L-face box, and placing the box on a non-magnetic surface; (S3) turning over and placing the non-magnetic L-faced box on the non-magnetic platform successively with each side as a bottom surface, when each face is used as the bottom surface, rotating the L-faced box around the vertical axis of the non-magnetic platform under uniform angle differences for R attitudes, and recording output values of a three-axis magnetic sensor and an inertial navigation system at each attitude; and (S4) establishing a linear system of equations with the total amount of the geomagnetic field as a constraint for joint solution to obtain comprehensive error model parameters and further obtaining a geomagnetic vector value under a geometrical coordinate system and a magnetic sensor coordinate system after calibration.

Description

technical field [0001] The invention belongs to the field of magnetic measurement, and specifically relates to a method for calibrating the error of a geomagnetic vector measurement system based on the Lagrangian multiplier method, mainly for the inherent error of a three-axis magnetic sensor, the soft magnetic and hard magnetic interference of the measurement system, and the three-axis magnetic Sensitive axis misalignment error between sensor and inertial navigation system. Background technique [0002] The geomagnetic field is a vector field. In the geographic coordinate system, its three components are northward component X, eastward component Y and vertical component Z. Generally speaking, the geomagnetic vector refers to these three components. Therefore, in actual measurement, the three-axis magnetic sensor is used to measure the projection component of the geomagnetic field in the direction of the sensitive axis of the magnetic sensor, and the Euler angle between it a...

AI Technical Summary

Problems solved by technology

However, the geomagnetic field vector obtained by the global geomagnetic model itself also has errors, which will affect the accuracy of parameter estimation, thereby reducing the accuracy of error calibration

[0008] In summary, the existing single-item error separation correction method cannot meet the requirements of geomagnetic vector measurement accuracy, and the error comprehensive correction method based on the global geomagnetic model also has inherent defects. Therefore, a comprehensive error correction method for geomagnetic vector measurement system is studied. The calibration method has certain theoretical significance and practical value

Images