Vibration gyro having bias correcting function

摘要

A vibration gyro having a structure for canceling a quadrature error generated by structural asymmetricity due to production tolerance and a means for correcting a bias value when an angular velocity is zero. In order to apply a counter torque to a sense mass for canceling the quadrature error, left correction comb electrodes are fixed to a substrate adjacent to a left drive mass, and comb electrodes opposed to the correction comb electrodes are arranged on an inner portion of a frame member which constitutes the left drive mass. By applying DC voltage to the correction electrodes, electrostatic force, for canceling the leakage rotational displacement of the sense mass generated when the input angular velocity is zero, is generated.

主权项

1. A vibration gyro comprising:
a sense mass fixed to a substrate by a second supporting element and configured to be rotatably excited about an axis perpendicular to a plane by a Coriolis force generated by an angular velocity; drive masses on right and left sides, each drive mass being suspended inside the sense mass by a first supporting element so that each drive mass is capable of being driven and vibrated in a direction parallel to the plane, wherein the drive masses are connected to each other by a connecting spring having elasticity in the direction of driving-vibration of the drive masses so that the drive masses represent an anti-phase vibration mode wherein the drive masses are vibrated at opposite phases, wherein the sense mass is configured to not be excited in the direction of the driving-vibration due to the driving-vibration of the drive masses; and a correction electrode positioned adjacent to the sense mass, the correction electrode configured to generate an electrostatic force by an AC voltage applied to the correction electrode based on a phase of a monitor output of the driving-vibration of the drive masses when an angular velocity is not input, to cancel a rotational torque applied to the sense mass due to the driving-vibration of the drive masses.