MEMS gyro drift compensation using multiple rate measurements derived from a single resonator

Axisymmetric resonators possess multiple pairs of nominally degenerate modes, each of which can be configured as a Corilois vibratory gyro. In this paper we report a technique to extract simultaneous angular rate measurements from the same resonator. Specifically, both of the n = 2 and n = 3 pairs of modes in a disk resonator are configured to yield measurements of angular rate. Although the short-term noise is uncorrelated between these rate measurements, the long-term drifts show very strong correlation. A technique is implemented to fuse the two measurements into a single estimate of rate with much lower drift thereby providing a technique for in-situ bias drift compensation.