Calibration method of strapdown inertial measurement unit three-axis accelerometer

Abstract

The invention discloses a calibration method of a strapdown inertial measurement unit three-axis accelerometer, and relates to the technical field of inertial navigation. According to the calibrationmethod, the zero deviation and the scale factor deviation are calculated through a pitch angle and a roll angle of a rest position and the output of the three-axis accelerometer, and the calibration of the zero deviation and the scale factor of the three-axis accelerometer is achieved. According to the calibration method, the roll angle or pitch angle of the inertial measurement unit rotating at ahorizontal position is not limited, alternatively, it may be less than 90 degrees and may also be greater than 90 degrees, for the inertial measurement unit which does not have an angle of more than90 degrees, the zero deviation and the scale factor change need to be assessed, and the calibration of the three-axis accelerometer also can be carried out. Moreover, during calibration, the change ofat least four position can be realized, compared with the existing calibration method of nineteen positions, eleven positions and twenty-four positions, the calibration time is greatly shortened, thecalibration efficiency is improved, and the method can meet the requirement of large-batch production.

Description

technical field [0001] The invention belongs to the technical field of inertial navigation, in particular to a method for calibrating the zero bias and scale factor of a three-axis accelerometer through a series of angular position changes of an inertial group. Background technique [0002] The three-axis accelerometer of the strapdown inertial group can provide the attitude angle during inertial navigation. The error of the three-axis accelerometer has a great influence on the accuracy of the inertial navigation. Therefore, the errors of the three-axis accelerometer must be checked before use. The parameters are calibrated, and corresponding compensation is performed according to the calibration results during the processing. [0003] The calibration of SIM accelerometer can be divided into discrete calibration and system-level calibration. Discrete calibration directly takes the output of the accelerometer as the observation quantity, and uses the least square method to c...

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Problems solved by technology

[0005] Aiming at the problem in the prior art that the inertial group does not have the ability to meet the calibration of the accelerometer when it is turned over an angle of more than 90 degrees, the present invention provides a calibration method for the three-axis accelerometer of the strapdown inertial group, which is carried out through a series of angular position changes of the inertial group. The calibration of the zero bias and scale factor of the accelerometer can realize the calibration of the accelerometer when the inertial group does not need to be turned over an angle of more than 90 degrees, and can achieve the accuracy of the existing calibration method

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