Rate sensing device

• US 20050092084A1
• Filed: 02/23/2004
• Published: 05/05/2005
• Est. Priority Date: 03/28/2003
• Status: Abandoned Application

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: McWilliam, Stewart, Rourke, Anthony Kevin, Fell, Christopher Paul
• Application Number:
  US10/490,845
• Publication Number:
  US 20050092084A1
• Time in Patent Office: Days
• US Class Current: 73/504.13
• CPC Class Codes: G01C 19/567 using the phase shift of a vibration node or antinode

Abstract

A rate sensing device includes a cylindrical vibratory resonator, a hemispherical vibratory resonator or a substantially planar vibratory resonator (1) having a substantially ring or hoop-like shape structure, which resonators have inner and outer peripheries extending around a common axis (2), first carrier mode drive means (18) for causing the resonator (1) to vibrate in a Cos n₁θ carrier mode to provide a first rate sensing channel along the common axis (2), where n₁ has an integer value of 2 or more, and second carrier mode drive means (19) for causing the resonator (1) to vibrate in a Cos n₂θ carrier mode to provide a second rate sensing channel along the common axis (2) where n₂ has an integer value of 2 or more and where n₂ is not equal to n₁, which first and second rate sensing channels are independent of one another and operate over different rate ranges where the rate range increases for higher values of n₁ and n₂.

Claims

1. A rate sensing device including a cylindrical vibratory resonator, a hemispherical vibratory resonator or a substantially planar vibratory resonator having a substantially ring or hoop-like shape structure, which resonators have inner and outer peripheries extending around a common axis, first carrier mode drive means for causing the resonator to vibrate in a Cos n₁θ

carrier mode to provide a first rate sensing channel along the common axis, where n, has an integer value of 2 or more, and second carrier mode drive means for causing the resonator to vibrate in a Cos n₂θ

carrier mode to provide a second rate sensing channel along the common axis, where n₂ has an integer value of 2 or more and where n₂ is not equal to n₁, which first and second rate sensing channels are independent of one another and operate over different rate ranges where the rate range increases for higher values of n₁ and n₂.

2. A device according to claim 1, in which the first carrier mode drive means and second carrier mode drive means are arranged at any arbitrary relative alignment around the resonator with respect to one another.

3. Device according to claim 1, wherein the first rate sensing channel is also provided with a first carrier mode pick-off means, a first response mode drive means and a first response mode pick-off means, and wherein the second rate sensing channel is provided with a second carrier mode pick-off means, a second response mode drive means, and a second response mode pick-off means.

4. A device according to claim 3, wherein the drive means and pick-off means are located at any radial anti-nodal position for a given vibration mode.

5. A device according to claim 3, including for each channel a carrier mode control loop and a response mode control loop.

6. A device according to claim 5, wherein each carrier mode control loop includes an Automatic Gain Control, a Voltage Controlled Oscillator and a Phase Lock Loop and wherein each response mode control loop includes a quadrature component loop and a real component loop.

7. A device according to claim 3, in which n₁=2 and n₂=3.

8. A device according to claim 7, in which the Cos 2θ

carrier mode drive means is positioned relative to the resonator at an angle of 0°

, the Cos 2θ

carrier mode pick-off means is positioned at 180°

, the Cos 2θ

response mode motion is detected by the Cos 2θ

response mode pick-off means located at 225° and

nulled by the Cos 2θ

response mode drive means positioned at 45°

, the Cos 3θ

carrier mode drive means is positioned at 330°

, the Cos 3θ

carrier mode pick-off means is positioned at 150°

, and the Cos 3θ

response mode motion is detected by the Cos 3θ

response mode pick-off means located at 120° and

nulled by the Cos 3θ

response mode drive means positioned at 300°

.

9. (canceled).