Online calibration method for three-axis TMR sensor

Abstract

The invention relates to an online calibration method for a three-axis TMR sensor. The sensor comprises a TMR sensor, an X axis, a Y axis and a Z axis. The calibration method of the TMR sensor comprises the following operation steps: initializing parameters, rotating a horizontal rotating machine body, and repeatedly acquiring a pitch angle theta and a roll angle gamma detected by an inertial navigation system and three-axis outputs MX, MY and MZ of the TMR magnetic sensor under a machine body coordinate system in the rotating process; establishing an elliptical orbit model of original magnetic field intensity vector rotation in a horizontal plane, and fitting based on a least square method to obtain magnetic calibration parameters; and after the machine body horizontally rotates for one circle, compensating the elliptical orbit into a circular orbit based on the plurality of groups of magnetic field intensity vectors H1 obtained in the step c and the magnetic calibration parameters obtained in the step e, and calculating the compensated magnetic field intensity. In brief, according to the technical scheme, an excellent optimization scheme is utilized, and the problem that calibration errors exist in a traditional magnetic sensor is solved.

Description

technical field [0001] The invention relates to the technical field of magnetic sensor applications, in particular to an online calibration method for a three-axis TMR sensor. Background technique [0002] The combination of inertia / geomagnetism, as a low-cost navigation method, is widely used in the fields of automatic driving and manipulation of unmanned aerial vehicles, unmanned ships, and unmanned vehicles. The magnetic sensor is the core component of geomagnetic navigation. Through sensitive The direction of the geomagnetic vector is used to calculate the magnetic heading and to correct the error accumulation caused by the inertial navigation. Since the strength of the earth's magnetic field is very weak, only about 0.5 gauss, it is easily disturbed by the external magnetic field. For example, the underwater unmanned submersible In the inertial / geomagnetic integrated navigation, due to the complex external magnetic field environment during navigation, severe geomagnetic...

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Problems solved by technology

[0004] In view of this, the purpose of the present invention is to solve the sensitive axis deviation problem of the three-axis TMR sensor under the interference of the complex external magnetic field, and to provide a method based on twice least square fitting and utilizing the accelerometer that has been calibrated to analyze the TMR The combined calibration scheme for sensor calibration can not only improve the measurement accuracy of TMR sensors in complex magnetic field environments, but also solve the problem of misalignment of the sensitive axes of the acceleration sensor and the magnetic sensor in the system

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