PLANAR CORIOLIS GYROSCOPE

• US 20130333470A1
• Filed: 03/08/2012
• Published: 12/19/2013
• Est. Priority Date: 03/08/2011
• Status: Active Grant

• Current Assignee: Y-Sensors, Ltd.
• Original Assignee: Y-Sensors, Ltd.
• Inventors: Netzer, Yishay, Girgel, Michael
• Granted Patent: US 9,303,994 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames

Abstract

A planar Coriolis gyroscope comprising at least two counter oscillating masses attached to a common rigid frame by means of a first plurality of elastic members and constituting an excitation axis, said frame is attached to a support region by means of a second plurality of elastic members which together with the masses constitute at least one Coriolis resonator. Said Coriolis resonator responds to inertial rotation of the gyroscope and in conjunction with a position pickoff provides a signal indicative on the gyroscope inertial rotation

Claims

1. An inertial rotation rate sensor comprising:

(a) a lower substrate;

(b) a device layer substantially parallel to said lower substrate, said device layer comprising;

(i) a substantially rigid frame supported by a first plurality of compliant members that extend from a support region attached to said lower substrate, and

(ii) at least two masses each supported by a second plurality of compliant members which extend from said frame,

such that said at least two masses in conjunction with said second plurality of compliant members make up a first resonator having at least a first mode of motion relative to said frame in which said at least two masses undergo counter-oscillation,

and such that said at least two masses and said frame in conjunction with said first plurality of compliant members make up a second resonator having at least a first mode in which said frame and said at least two masses oscillate together relative to said lower substrate;

(c) an actuator deployed for exciting oscillatory motion of one of said first and second resonators, referred to as the excitation resonator; and

(d) a position pickoff deployed for sensing a current position of the other of said first and second resonators, referred to as the Coriolis resonator,

such that, when said excitation resonator is driven via said actuator in an oscillatory motion, said oscillatory motion combines with an inertial rotation rate around at least a first rotation axis to generate a Coriolis force acting on said at least two masses to excite the first mode of said Coriolis resonator, thereby allowing derivation of the inertial rotation rate about the first rotation axis.

2. The sensor of claim 1, wherein said first resonator is said excitation resonator and said second resonator is said Coriolis resonator.

3. The sensor of claim 2, wherein said first mode of said Coriolis resonator is an in-plane rotational mode.

4. The sensor of claim 3, further comprising a second position pickoff deployed for sensing a position of said Coriolis resonator in a second out-of-plane rotational mode, thereby allowing sensing of a second inertial rotation rate about a second rotation axis.

5. The sensor of claim 2, wherein said first mode of said Coriolis resonator is an out-of-plane rotational mode.

6. The sensor of claim 1, wherein said second resonator is said excitation resonator and said first resonator is said Coriolis resonator.

7. The sensor of claim 1, further comprising a processing system including at least one processor, said processing system being associated with said actuator and said position pickoff, and being configured to:

(i) actuate said actuator so as to generate oscillatory motion of said excitation resonator, and

(ii) process a signal from said position pickoff indicative of a motion of said Coriolis oscillator, thereby determining the inertial rotation rate about the first rotation axis.

8. The sensor of claim 1, wherein said position pickoff is part of a force balance arrangement deployed for opposing motion of said Coriolis oscillator, the sensor further comprising a processing system including at least one processor, said processing system being associated with said actuator and said force balance arrangement, and being configured to:

(i) actuate said actuator so as to generate oscillatory motion of said excitation resonator, and

(ii) process a signal from said force balance arrangement indicative of a magnitude of said Coriolis force on said at least two masses, thereby determining the inertial rotation rate about the first rotation axis.