Patent ID: 8549915

Claim:
A micromachined z-axis vibratory rate gyroscope comprising: a first 1-DOF drive subsystem restrained to oscillate substantially only in the drive mode, and having a drive suspension and drive mass, and wherein the 1-DOF drive subsystem further comprises: an outer anchor; an inner anchor; an outer decoupling frame coupled to the outer anchor by at least one drive suspension that constrains the motion of the outer decoupling frame to substantially only the drive axis; and an inner decoupling frame coupled to the inner anchor and at least one drive suspension that constrains the motion of the outer decoupling frame to substantially only the drive axis; and a 2-DOF sense subsystem restrained to oscillate substantially only in the sense mode, having at least two sense mode resonant frequencies, and resiliently coupled to the 1-DOF drive subsystem, where the 1-DOF drive subsystem has a drive frequency independent of the at least two sense mode resonant frequencies, which drive frequency is determined by selection of dynamic parameters for the drive suspension and drive mass, and wherein the 2-DOF sense subsystem further comprises: a first sense mass m a coupled to one of either the inner decoupling frame or the outer decoupling frame and restrained to oscillate substantially only in the sense direction; a second sense mass m b coupled to the other one of either inner decoupling frame or outer decoupling frame and restrained to oscillate substantially only in the sense direction; and an independent flexure coupling the first and second sense masses to allow relative motion of the first and second sense masses ma and mb in substantially only in the sense direction.