Non-alignment error correction method used for geomagnetic element measuring system

Abstract

The invention discloses a non-alignment error correction method used for a geomagnetic element measuring system, which comprises the following steps: (1) a rectangular table-board is arranged and a reference coordinate system for the rectangular table-board is established; (2) a magnetic sensor of the geomagnetic element measuring system and an accelerometer are encapsulated together in a non-magnetic regular hexahedron; two surfaces of the non-magnetic regular hexahedron are attached to two vertical surfaces of the rectangular table-board; and a regular hexahedron coordinate system is established for the non-magnetic regular hexahedron; (3) the non-magnetic regular hexahedron is turned for multiple times, and after multiple times of turning, the non-magnetic regular hexahedron is still attached to the rectangular table-board; (4) multiple sets of measurement values of the non-magnetic regular hexahedron and the accelerometer during the process of multiple times of turning are utilized, and through solving multiple non-linear equations simultaneously, the non-alignment error of the magnetic sensor and the non-alignment error of the accelerometer are calculated; (5) the non-alignment error between the magnetic sensor and an inertial navigation is indirectly calculated to correct the non-alignment error of the measurement value of the magnetic sensor. The method has the advantages of simple principle, facilitation of realization and operation, higher correction accuracy, etc.

Description

technical field [0001] The invention mainly relates to the technical field of magnetic measurement, in particular to a non-alignment error correction method for a geomagnetic element measurement system. Background technique [0002] Geomagnetic measurement sensors can be divided into two categories: total type and three-component type according to the difference of the measured. The "total type" measurement is the total strength of the geomagnetic field, which is customarily called scalar measurement; the "three-component type" measurement is the projection size of the total geomagnetic field on the three sensitive axes of the magnetic sensor. If the Euler angle relationship between the rectangular coordinate system formed by the three sensitive axes of the magnetic sensor and the geographic coordinate system is known, all seven elements of the geomagnetic field vector can be obtained through mathematical transformation: the northward component of the geomagnetic field, the ...

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Problems solved by technology

However, this method requires precise adjustment of the three-dimensional coordinate system of the optical system, and the local magnetic inclination information is needed, and the initial coordinate system of the regular hexahedral optical prism is consistent with the local north, east, and ground coordinate systems

Therefore, this method has high requirements for the precise adjustment of the initial coordinate system of the optical system and the optical prism.

[0007] 3. Using a six-dimensional DOF robot to correct misalignment errors; similarly, this method requires precise control of the attitude and is complex to operate

[0009] 5. Some practitioners package the magnetic sensor and accelerometer into an open plastic resin material regular hexahedron, place the regular hexahedron on a non-magnetic flat plate, and then rotate it around the axis perpendicular to the regular hexahedron and the flat plate, using the magnetic field of the rotating axis According to the invariant principle of gravity projection, the misalignment error of the magnetic sensor and accelerometer to the regular hexahedron coordinate system is calculated respectively, but this method also needs to know the magnetic field value in the direction of the rotation axis

[0010] All in all, all the above-mentioned existing correction methods for misalignment angle errors have disadvantages such as complicated operation, and all require the use of geomagnetic vector information, magnetic field angle information, and attitude information provided by GPS or accelerometers. High requirements affect the calibration accuracy

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