Overview of CVG Gyroscope Technology
Solid-state Coriolis Vibrating Gyroscopes are based on the control of two standing waves in a physical body. This body is a resonator which is designed as an axisymmetrical shape, as axisymmetrical shapes lead to top of the range performances.
The following picture show the InnaLabs’ CVG sensitive element (SE). This sensitive element is common to all InnaLabs® CVG products.
Each SE consists of a cylindrical resonator which has two flexural second order resonant modes which occur at the same nominal frequency. The geometric shape of the resonance modes takes the form of an elliptical oscillation with four antinodes and four nodes located circumferentially along the rim.
The SE is excited such that the first flexural resonance mode is maintained on the resonance maximum and at a constant amplitude (Mode 1), with the second principle resonance mode being used to sense rotation (Mode 2).
A closed-loop system is used to drive the second flexural mode to zero and the force required to null this mode is proportional to the input rotation rate. The corresponding control loop system is called the force-rebalanced mode.
In order to provide forces and to sense induced motions, piezo-electric elements are attached to the base of the resonator. This electromechanical system is particularly effective and leads to low output noise and large dynamic range as required in case of demanding applications.