The two classes of vibrating gyroscopes

Unlike mechanical spinning-top gyroscopes, where the number of varieties is relatively small, there is a profusion of vibrating gyroscope formulas that differ in terms of resonator shape, transducer elements (electromechanical coupling between the mechanical resonator and the electronics), operating mode, technology and materials.

The most common operate in gyrometer mode. One of the resonance modes of the elastic body is maintained at a given amplitude. When the device rotates around a particular axis, the resultant Coriolis forces acting on the resonator's moving masses excite a second resonance mode. Sperry's first Gyrotron operated on this principle: the maintained mode is the natural vibration mode of the tuning fork in phase opposition; the second mode is the torsion mode of the tuning fork around its longitudinal axis.

The speed at...