Compensation of Non-Orthogonality Changes in Low-Cost MEMS Gyroscopes Across Soldering, Temperature and Lifetime

Abstract

This paper examines changes of non-orthogonality in 40 consumer-grade, triaxial MEMS gyroscopes across three different environmental conditions: Soldering, temperature and accelerated lifetime testing. We find that through all three treatments, similar correlations of $yx$ non-orthogonality change to z-axis quadrature change appear. We attribute the behavior to a common susceptibility to mechanical stress. Consequently, we evaluate the feasibility of an in-run, active compensation of non-orthogonality using only the sensor-internal quadrature signal. Improved $yx$ non-orthogonalities reach stability between $\pm 0.021{\%}$ and $\pm 0.040{\%}$ with a reduction of −73% across soldering, up to −69% across temperature and −55% across lifetime. We also demonstrate that the non-orthogonality changes of the devices across each of the three environmental conditions do not correlate to each other. It is furthermore shown, that the other two non-orthogonalities, $zx$ and $zy$, offer excellent stability below $\pm 0.015{\%}$ across temperature solely by design.