Patent ID: 8910521

Claim:
Vibrating structure gyrometer with at least one tuning fork, produced by micro-machining from a thin plate, the said tuning fork comprising a pair of mobile inertial assemblies (EIM 1 , EIM 2 ) linked by a coupling assembly ( 1 ), one mobile inertial assembly (EIM 1 , EIM 2 ) being furnished with first stiffness elements ( 2 , 2 ′) essentially deformable in the plane of the plate along a drive axis x and with second stiffness elements ( 3 , 3 ′) essentially deformable in the plane of the plate along a sense axis y substantially perpendicular to the x axis, the gyrometer comprising, furthermore, for the tuning fork, two first controlled electrodes ( 4 , 4 ′) for electrostatic excitation along the drive axis x which are respectively associated with the two mobile inertial assemblies (EIM 1 , EIM 2 ), two second controlled electrodes ( 5 , 5 ′) for capacitive detection of the drive resonator along the drive axis x which are respectively associated with the two mobile inertial assemblies (EIM 1 , EIM 2 ), two third controlled electrodes ( 6 , 6 ′) for capacitive detection of the drive motion along the sense axis y which are respectively associated with the two mobile inertial assemblies (EIM 1 , EIM 2 ), and: two fourth controlled electrodes ( 9 , 9 ′) for electrostatic equilibration of the sense resonator along the sense axis y which are respectively associated with the two mobile inertial assemblies (EIM 1 , EIM 2 ) of the said tuning fork, characterized in that it comprises: control means (UCE) adapted for applying two respective continuous electrical voltages V 1 and V 2 to the said two fourth electrodes ( 9 , 9 ′) satisfying the relation V 1 2 - V 2 2 = c y_initial a ⁢ ⁢ λ , in which c y — initial represents the initial sensitivity of the gyrometer, when the two electrical voltages V 1 and V 2 are zero, to linear accelerations along the sense axis y, in deg·h −1 ·G −1 , a represents a coefficient characterizing the influence of a discrepancy in stiffness between the two branches of the tuning fork on the sensitivity of the gyrometer to linear accelerations along the y axis, in deg·h −1 ·G −1 ·N −1 ·m, λ represents an electrostatic stiffness coefficient dependent on the said two fourth electrodes ( 9 , 9 ′) in N·m −1 ·V −2 , V 1 and V 2 are expressed in Volts, and G equals 9.81 m·s −2 .