MEMS gyroscope bias drift cancellation using continuous-time mode reversal

A continuous-time mode-reversal technique demonstrates reduction of bias drift of a MEMS pendular gyroscope. The technique relies on continuous excitation of two axes of the gyroscope. Forces required to maintain a particular proof-mass trajectory indicate the angular rate. The individual forcers also contain correlated error terms which can be cancelled with an appropriate linear combination. This technique demonstrates an Allan-deviation improvement from 9 deg/hr to 2 deg/hr on a 3.3kHz MEMS vibratory gyroscope.