Calibration of the triaxial navigation accelerometers unit using the mathematical apparatus of eleptic functions

Abstract

This paper presents the alternative calibration technique of a triaxial This paper presents the alternative calibration technique of a triaxial accelerometer unit based on the ellipsoid fitting. The proposed method allows performing high-quality identification of the metrological model parameters of the unit in the absence of information about its spatial orientation. The fitting procedure is based on the geometry constraint of an ellipsoid and insensitiveness to small errors in the data. The effectiveness of the proposed method was confirmed during the experiment using a block based on the navigation accelerometer A-17. The calibration results have been validated using professional calibration tools. Based on a series of tests, the measurement accuracy of this unit can reach 3·10 -5 g, which means that the proposed method has high calibration accuracy and can meet the application requirements of the navigation triaxial unit of accelerometers. Described technique can also be used with other sensors, such as gyroscopes or magnetometers. However, the inability to use the calibrated unit in the IMU orthogonal coordinate system results in the impossibility of calibrating several units in one coordinate system.