Integrated calibration method for gyro and magnetic transducer

Abstract

The invention provides an integrated calibration method for a gyro and a magnetic transducer. The method is characterized by comprising the following steps: step 1, obtaining an associated measuring model of the magnetic transducer and the gyro, wherein the measuring model includes a calibration parameter; and step 2, adopting constraint non-linear least square estimation based on the calibration parameter to obtain a determined value of the calibration parameter. Compared with a method in the prior art, the integrated calibration method has the following beneficial effects: 1, both a misalignment angle between the magnetic transducer and the gyro and a gyro zero offset are calibrated; 2, in a calibration process, the more stable the magnetic field is, the better the calibration effect is, and the calibration effect is not interfered by any accelerated speed, so that the gyro and the magnetic transducer do not need to be kept in a stationary state; and 3, the method can be used for attitude rectification of the magnetic transducer and an inertia measuring unit (including the gyro and an accelerometer).

Description

technical field [0001] The invention relates to the technical field of sensors, in particular to a joint calibration method of a gyroscope and a magnetic sensor. Background technique [0002] Gyroscopes and magnetic sensors (the latter also known as magnetometers, magnetometers) are often used in the field of attitude determination or scientific measurements. The gyro is sensitive to the angular velocity of the carrier, and the magnetometer is sensitive to the ambient magnetic field. When the magnetometer is near ferromagnetic materials, the magnetic field around the magnetometer is distorted, and the magnetic field strength cannot be measured correctly. Magnetic field interference can be divided into hard magnetic effect and soft magnetic effect. The hard magnetic effect is the additive magnetic interference produced by permanent magnets or currents, while the soft magnetic effect is induced by soft magnetic materials. The soft magnetic materials in the background magneti...

AI Technical Summary

Problems solved by technology

The commonly used magnetometer calibration method takes advantage of the fact that the local magnetic field strength has nothing to do with the attitude of the magnetometer. The advantage is that no external auxiliary equipment is required, and the disadvantage is that it cannot calibrate the misalignment angle of the coordinate system between the magnetometer and other sensors.

On the other hand, the zero bias error of low-cost gyroscopes (such as MEMS gyroscopes) is relatively large, and it changes every time it is used. If the measured values ​​​​of the gyroscope are directly used without compensation, it will affect the misalignment of the coordinate system between the magnetometer and the gyroscope. Corner Calibration Effect

Images