Rates and temperature optimized measurement planning for triaxial gyroscopes calibration

Abstract

This work is concerned with the optimization of triaxial gyroscopes’ thermal calibration. Previous works mostly focused on advanced modeling and estimation techniques while assuming standard time profiles of the angular rates and temperature measurements, typically steps or piecewise-linear, that span the whole operational range. As a result, calibration tests are long and costly processes and not as efficient as they could be. In this work, we introduce a systematic approach to conducting a calibration experiment more efficiently. The calibration experiment is designed to maximize its accuracy by choosing the best combination of temperature and angular rate measurement planning. This is achieved by maximizing the determinant of the observability Gramian associated with the gyro error model, subject to constraints due to the turntable and thermal chamber operational limits. The outcome is an optimized measurement planning that provides the best accuracy for a given calibration time. Numerical and experimental results on a Coriolis vibratory gyro show that the optimized approach outperforms a standard temperature ramp profile, by up to one order of magnitude in the angular rate prediction error.