Micromachined vibratory gyroscope with electrostatic coupling

US6966224B2 · kind B2 · utility

Assignees

• BEI Technologies, Inc. · US
• Conti Temic microelectronic GmbH · DE
• Continental Teves AG & Co. OHG · DE

Inventors

• Hai Yan · Chapel Hill, US
• Roland Burghardt · Frankfurt am Main, DE
• Bernhard Hartmann · Birkenfeld, DE
• Konrad Kapser · Gräfelfing, DE
• Matthias Rose · Eindhoven, NL

Key dates

• Filing date: Mar 2, 2004
• Grant date: Nov 22, 2005
• Expiry date: Mar 2, 2024

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T74/1275
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Micromachined vibratory gyroscope having two or more coplanar movable masses suspended over a planar substrate. Two perpendicular axes (x and y) are defined within the substrate plane, while a third, the z-axis or input axis, is defined to be perpendicular to the substrate plane. The movements of the two masses along the x-axis are coupled through an electrostatic coupling means so that the natural resonant frequency of the in-phase mode and that of the anti-phase mode are separated from each other for the resonances along the x-axis. When the two masses are driven to vibrate along the x-axis in the anti-phase mode and the device experiences rotation about the z-axis, Coriolis forces act differentially on the masses in the Y-direction, causing the two masses to dither in an anti-phase motion along the y-axis. The anti-phase dithering along the y-axis can be sensed directly by a rate sensor to measure the rate of rotation about the z-axis. Alternatively, the anti-phase dithering of the first and second bodies along the y-axis can be transferred to other movable bodies (i.e., rate-sensing masses) whose movement is then sensed to measure the rate of rotation about the z-axis. The sens…