Patent ID: 8677821
Filing Date: 2014-03-25
Classification: G01C

Abstract:
1. A mode matching method for use with a microelectromechanical systems gyroscope, comprising: determining a current zero rate output level of the gyroscope; storing the current zero rate output level; determining if the current zero rate output level is greater than or equal to a previous zero rate output level; if the current zero rate output level is less than the previous zero rate output level, incrementing a counter, increasing polarization voltage applied to the gyroscope, and determining the zero rate output level of the gyroscope; if the current zero rate output level is greater than or equal to the previous zero rate output level, decreasing the polarization voltage applied to the gyroscope, and verifying a phase difference (.DELTA. .phi.) between drive and sense signals applied to and derived from the gyroscope; iteratively incrementing the polarization voltage until a maximum in residual zero rate output amplitude level is detected; monitoring a 90.degree, phase difference to ensure that mode-matching is achieved; and once mode matching is achieved, controlling a bandwidth of the gyroscope by varying the polarization voltage to introduce a controlled frequency separation between drive and sense resonant modes of the gyroscope.