US 6,439,050 B1Granted

Compensated integrated micro-machined yaw rate sensor with quadrature switching

AssigneeMelexis NV

InventorsFrancois-Xavier Musalem, William R. Betts, Roger Diels

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Abstract

An integrated circuit combines micro-machined elements, piezoelectric elements and signal processing components as part of a compensated oscillating gyroscopic sensor for angular motion detection. An oscillating mass is supported on a number of flexible beams micro-machined into an integrated circuit device, such as a silicon CMOS device. Several Piezo-electric elements, deposited on the beams, are provided to excite the mass and to measure the accelerations. Integrated in the device are electronic circuitry that initiates and maintains the oscillation and electronic circuitry that detects and measures the subsequent motion. Additional circuitry is also provided to eliminate the effects of quadrature oscillation and to determine the Coriolis acceleration and thus the magnitude of the external perturbing velocity.

Claims15

Dependent claims

A micro-machined gyro sensor capable of measuring an externally imposed velocity comprising:

a mass coupled to a rigid annular support by a first pair of opposing flexible members and a second pair of opposing flexible members, wherein the first pair of members define a first axis, and wherein the second pair of members define a second axis substantially orthogonal to the first axis;
a first pair of piezo electric driving elements deposited on the first pair of members;
a first piezo electric sensing element deposited on one of the first pair of members, wherein the first sensing element generates a first signal proportional to the oscillation of the mass along the first axis;
a second pair of piezo electric driving elements deposited on the second pair of members;
a second piezo electric sensing element deposited on one of the second pair of members, wherein the second sensing element generates a second signal proportional to the oscillation of the mass along the second axis;
a control circuit coupled to the first and second sensing elements and to the first pair of driving elements, wherein the control circuit generates a control signal which when applied to the first pair of driving elements causes the mass to oscillate along the first axis;
and
a detection circuit coupled to the first and second sensing elements, wherein the detection circuit receives the first and second signals and generates an output signal proportional to the imposed velocity;
wherein the control circuit receives the first and second signals and generates a signal proportional to an undesired oscillation of the mass along the second axis so as to compensate for the undesired oscillation along the second axis when applied to the second pair of driving elements.

6 more elements

A micro-machined gyro sensor capable of measuring an externally imposed velocity comprising:

a mass coupled to a rigid annular support by a first pair of opposing flexible members and a second pair of opposing flexible members, wherein the first pair of members define a first axis, and wherein the second pair of members define a second axis substantially orthogonal to the first axis;
first driving means coupled to the first pair of members for causing the mass to oscillate along the first axis;
second driving means coupled to the second pair of members for causing the mass to oscillate along the second axis;
detection means, coupled to the first pair of members and the second pair of the second pair of members, for detecting and comparing oscillations of the mass along the first axis and along the second axis so as to measure the Coriolis acceleration caused by the imposed velocity;
a first sensing means, deposited on one of the first pair of members, for generating a first signal proportional to the oscillation of the mass along the first axis;
a second sensing means, deposited on one of the second pair of members, for generating a second signal proportional to the oscillation of the mass along the second axis;
and
a control means is coupled to the first and second sensing means and the first and second driving means and includes a means for comparing the first and second signals to determine an undesired oscillation of the mass along the second axis and for generating signals so as to compensate for the undesired oscillation when applied to the first and second driving means.

5 more elements

Dependencies are inferred from the claim text.