Vibrating structure gyrometer with at least one tuning fork

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 (EIM1, EIM2) linked by a coupling assembly (1), one mobile inertial assembly (EIM1, EIM2) 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 (EIM1, EIM2), 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 (EIM1, EIM2), 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 (EIM1, EIM2), 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 (EIM1, EIM2) of the said tuning fork, characterized in that it comprises:
• control means (UCE) adapted for applying two respective continuous electrical voltages V1 and V2 to the said two fourth electrodes (9, 9′) satisfying the relation
• V
• 1
• 2
• -
• V
• 2
• 2
• =
• c
• y_initial
• a
• ⁢
• ⁢
• λ
• ,
• in which cy—initial represents the initial sensitivity of the gyrometer, when the two electrical voltages V1 and V2 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, V1 and V2 are expressed in Volts, and G equals 9.81 m·s−2.