Oscillating voltage of sense electrodes in a MEMS tuning fork gyroscope
First Claim
1. A method for operating a micro-electro-mechanical system (MEMS) tuning fork gyroscope, the method comprising:
- applying a first AC drive signal to a first in-plane electrode that is in-plane with a first proof mass in order to induce in-plane motion on the first proof mass;
oscillating a first voltage on a first sense electrode out-of-plane from and proximate a first side of the first proof mass between a first voltage value and a second voltage value at a first frequency, wherein the first voltage value is different from the second voltage value;
oscillating a second voltage on a second sense electrode out-of-plane from and proximate a second side of the first proof mass between the first voltage value and the second voltage value at the first frequency and 180 degrees out-of-phase with the first voltage on the first sense electrode; and
generating a rate signal corresponding to a rotation rate of the first proof mass by first demodulating an out-of-plane signal from the first proof mass at the first frequency and second demodulating the out-of-plane signal in phase with in-plane motion of the first proof mass.
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Abstract
Embodiments of the subject application provide a method for operating a micro-electro-mechanical system (MEMS) tuning fork gyroscope. The method includes oscillating a voltage on a first sense electrode out-of-plane from and proximate a first side of a first proof mass between a first voltage and a second voltage at a first frequency. The method also includes oscillating a voltage on a second sense electrode out-of-plane from and proximate a second side of the first proof mass between the first voltage and the second voltage at the first frequency and 180 degrees out-of-phase with the voltage on the first sense electrode. The method also includes generating a rate signal corresponding to a rotation rate of the first proof mass by first demodulating an out-of-plane signal from the first proof mass at the first frequency and second demodulating the out-of-plane signal in phase with in-plane motion of the first proof mass.
13 Citations
20 Claims
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1. A method for operating a micro-electro-mechanical system (MEMS) tuning fork gyroscope, the method comprising:
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applying a first AC drive signal to a first in-plane electrode that is in-plane with a first proof mass in order to induce in-plane motion on the first proof mass; oscillating a first voltage on a first sense electrode out-of-plane from and proximate a first side of the first proof mass between a first voltage value and a second voltage value at a first frequency, wherein the first voltage value is different from the second voltage value; oscillating a second voltage on a second sense electrode out-of-plane from and proximate a second side of the first proof mass between the first voltage value and the second voltage value at the first frequency and 180 degrees out-of-phase with the first voltage on the first sense electrode; and generating a rate signal corresponding to a rotation rate of the first proof mass by first demodulating an out-of-plane signal from the first proof mass at the first frequency and second demodulating the out-of-plane signal in phase with in-plane motion of the first proof mass. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A micro-electro-mechanical system (MEMS) tuning fork gyroscope comprising:
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a first planar proof mass defining a first surface and a second surface; a first sense electrode out-of-plane from the first proof mass and proximate the first surface; a second sense electrode out-of-plane from the first proof mass and proximate the second surface; a first in-plane electrode having a comb that interleaves with a comb on the first planar proof mass; and control electronics configured to; apply a first AC drive signal to the first in-plane electrode to induce in-plane drive motion on the first proof mass; apply a first oscillating voltage to the first sense electrode and a second oscillating voltage to the second sense electrode, wherein the first oscillating voltage oscillates between a first voltage value and a second voltage value at a first frequency, and wherein the second oscillating voltage oscillates between the first voltage value and the second voltage value at the first frequency and 180 degrees out-of-phase from the first oscillating voltage, wherein the first voltage value is different from the second voltage value; and determine a signal corresponding to a rotation rate of the first proof mass by first demodulating an out-of-plane signal from the first proof mass at the first frequency and second demodulating the out-of-plane signal in phase with in-plane drive motion of the first proof mass. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A micro-electro-mechanical system (MEMS) tuning fork gyroscope comprising:
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a first planar proof mass defining a first surface and a second surface; a first sense electrode out-of-plane from the first proof mass and proximate the first surface; a second sense electrode out-of-plane from the first proof mass and proximate the second surface; a first in-plane electrode having a comb that interleaves with a comb on the first planar proof mass; a second planar proof mass in-plane with the first proof mass and defining a third surface and a fourth surface, wherein the third surface faces the same direction as the first surface; a third sense electrode out-of-plane from the second proof mass and proximate the third surface; a fourth sense electrode out-of-plane from the second proof mass and proximate the fourth surface; a second in-plane electrode having a comb that interleaves with a comb of the second planar proof mass; and control electronics configured to; apply a first AC drive signal to the first in-plane electrode to induce in-plane drive motion on the first proof mass; apply a second AC drive signal to the second in-plane electrode to induce in-plane drive motion on the first proof mass; apply a first oscillating voltage to the first sense electrode and a second oscillating voltage to the second sense electrode, wherein the first oscillating voltage oscillates between a first voltage value and a second voltage value at a first frequency, and wherein the second oscillating voltage oscillates between the first voltage value and the second voltage value at the first frequency and 180 degrees out-of-phase from the first oscillating voltage, wherein the first voltage value is different from the second voltage value; apply the first oscillating voltage to the fourth sense electrode and the second oscillating voltage to the third sense electrode; and determine a signal corresponding to a rotation rate of the first and second proof masses by first demodulating an out-of-plane signal from the first and second proof masses at the first frequency and second demodulating the out-of-plane signal in phase with in-plane drive motion of the first and second proof mass. - View Dependent Claims (20)
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Specification