QUADRATURE COMPENSATION FOR A ROTATION-RATE SENSOR

• US 20100132461A1
• Filed: 11/23/2009
• Published: 06/03/2010
• Est. Priority Date: 11/25/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hauer, Joerg, Gauger, Christoph
• Granted Patent: US 8,650,954 B2
• Time in Patent Office: Days
• US Class Current: 73/504.120
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames

Abstract

A rotation-rate sensor includes a substrate having a surface, a movable element situated above the surface, which is deflectable based on a Coriolis force along a first axis that runs perpendicular to the surface, a driving device which is prepared to activate the movable element along a second axis that runs parallel to the surface, a compensation device, in order to generate an electrostatic force along the first axis, including electrodes corresponding to one another, developed on the substrate and on the movable element; a relative degree of covering of the electrodes in the direction of the first axis being a function of the deflection of the movable element along the second axis; and the electrode developed on the movable element runs around an insulating region of the movable element.

Claims

1. A rotation-rate sensor comprising:

a substrate having a surface;

a movable element situated above the surface, that is deflectable, based on a Coriolis force, along a first axis running perpendicular to the surface;

a driving device for activating the movable element along a second axis that runs parallel to the surface; and

a compensation device for generating an electrostatic force along the first axis including electrodes that correspond to one another, situated on the substrate and on the movable element, a relative degree of covering of the electrodes in a direction of the first axis being a function of a deflection of the movable element along the second axis, at least one of the electrodes being situated on the movable element and extending around an insulating region of the movable element.

2. The rotation-rate sensor according to claim 1, wherein the insulating region is a recess in the movable element.

3. The rotation-rate sensor according to claim 1, wherein a number of insulating regions in an edge region of the movable element have the electrode extending around them in such a way that fissures in an edge region of the movable element, that runs perpendicular to the first axis, are minimized.

4. The rotation-rate sensor according to claim 3, wherein the edge region of the movable element forms four substantially straight outer edges.

5. The rotation-rate sensor according to claim 4, wherein a number of elastic elements are fastened to the outer edges of the movable element.

6. The rotation-rate sensor according to claim 1, wherein first and second of the electrodes are situated on the substrate and are situated on different sides of a center line, which runs in a direction of a third axis that runs perpendicular to the second axis and parallel to the surface.

7. The rotation-rate sensor according to claim 6, wherein an insulating region of the movable element is situated symmetrically over the center line in a deflection-free position of the movable element in a direction of the second axis.

8. The rotation-rate sensor according to claim 6, wherein a first voltage applied between the electrode of the movable element and the first electrode is different from a second voltage applied between the electrode of the movable element and the second electrode.

9. The rotation-rate sensor according to claim 8, wherein the first and second voltages differ in their signs, so that as a function of the sign of a deflection of the movable element along the second axis, an attractive or a repulsive force is exerted between the movable element and the substrate along the first axis.