Gyro platform assembly

• US 5,406,858 A
• Filed: 10/22/1993
• Issued: 04/18/1995
• Est. Priority Date: 10/22/1993
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Brainard, Robert E.
• Primary Examiner(s): Bonck, Rodney H.
• Application Number:
  US08/139,655
• Time in Patent Office: 543 Days
• Field of Search: 74/5.22, 74/5.34
• US Class Current: 74/5.34
• CPC Class Codes: G01C 19/04 Details
• CPC Class Codes: G01C 21/18 Stabilised platforms, e.g. by gyroscope
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: Y10T 74/1221 Multiple gyroscopes

Abstract

A gyro platform assembly for determining a drift rate of a sensing axis of first gyro, the sensing axis being fixedly aligned to a carrousel axis. The first gyro is on a plane of a first platform. The first platform is connected to a vehicle along the carrousel axis. The first platform has the plane and an opening. A second platform is connected to the first platform within the opening. The second gyro is on a surface of the second platform. The second platform is carrouselable around a carrousel axis that is perpendicular to the carrousel axis of the first platform. The second gyro has a sensing axis that is adjustibly aligned with the sensing axis of the first gyro. When the vehicle rotates, each sensing axis experiences the same rotation rate. Each sensing axis produces a signal that is the result of the rotation rate of the vehicle, and a sensing axis drift rate. The second platform is carrouseled 180 degrees and the sensing axis of its gyro produces another signal. The drift rate of the sensing axis of the first gyro is determined from the three produced signals.

Claims

1. A gyro platform assembly, comprising:

(a) first platform means having a plane and an opening, for supporting a gyro means, the first platform means being supported along a carrousel axis;

(b) first gyro means located on the plane of the first platform means for sensing for rotation, the first gyro means having two mutually orthogonal sensing axes, a first sensing axis being orthogonal to the carrousel axis of the first platform means and a second sensing axis being in line with the carrousel axis of the first platform means;

(c) means for rotating the first platform means around its carrousel axis;

(d) second platform means having a surface and connected to the first platform means within the opening of the first inertial platform means, for supporting a second gyro means, the second platform means being supported along a carrousel axis, the carrousel axis of the second platform means being orthogonal to the carrousel axis of the first platform means;

(e) second gyro means located on the surface of the second platform means for sensing for rotation, the second gyro means having two mutually orthogonal sensing axes, a first sensing axis of the second gyro means being orthogonal to the carrousel axis of the first platform means and a second sensing axis of the second gyro means being alignable with the carrousel axis of the first platform means; and

(f) carrousel means for carrouseling the second platform means around its carrousel axis.

2. A gyro platform assembly, comprising:

(a) first platform means having a plane and an opening, for providing support, the first platform means having a carrousel axis;

(b) first rate-gyro means located on the plane of the first platform means, the first rate-gyro means having a sensing axis substantially in line with the carrousel axis of the first platform means, for sensing for rotation;

(c) means for rotating the first platform means around its carrousel axis;

(d) second platform means having a surface and being connected to the first platform means within the opening, for providing support, the second platform means having a carrousel axis that is substantially perpendicular to the sensing axis of the first rate-gyro means;

(e) second rate-gyro means located on the surface of the second platform means, the second rate-gyro means having a sensing axis that is substantially alignable with the sensing axis of the first rate-gyro means, for sensing for rotation;

(f) means for carrouseling the second platform means around its carrousel axis; and

(g) computer means for calculating a drift rate of the sensing axis of the first rate-gyro means from a signal from the sensing axis of the first rate-gyro means, a signal from the sensing axis of the second rate-gyro means, and a signal from the sensing axis of the second rate-gyro means after the second platform means is carrouseled 180 degrees.

3. A gyro platform assembly, comprising:

(a) first platform means having a plane and an opening, for providing support, the first platform means having a carrousel axis;

(b) first two-degree-of-freedom rate-gyro means located on the plane of the first platform means for sensing for rotation, a first sensing axis of its two orthogonal sensing axes being in line with the carrousel axis of the first platform means;

(c) means for rotating the first platform means around its carrousel axis;

(d) second platform means having a surface, for providing support, the second platform means being connected to the first platform means within the opening, the second platform means having a carrousel axis that is substantially perpendicular to the first sensing axis of the first rate-gyro means;

(e) second two-degree-of-freedom rate-gyro means located on the surface of the second platform, for sensing for rotation, a first orthogonal sensing axis being substantially alignable with said first sensing axis of the first rate-gyro means at which time the other of its sensing axes is orthogonal to the two sensing axes of the first rate-gyro means;

(f) means for carrouseling the second platform means around its carrousel axis; and

(g) computer means for calculating a drift rate of the first sensing axis of the first rate-gyro means from a signal from the sensing axis of the first rate-gyro means, a signal from the first sensing axis of the second rate-gyro means, and a signal from the first sensing axis of the second rate-gyro means after the second platform means is carrouseled 180 degrees.

4. A gyro platform assembly, comprising:

(a) first platform means having a plane and an opening, for providing support, the first platform means having a carrousel axis;

(b) first two-degree-of-freedom rate-gyro means located on the plane of the first platform means, the first rate-gyro means having a first sensing axis of its two sensing axes in line with the carrousel axis of the first platform means, for sensing for rotation;

(c) means for rotating the first platform means around its carrousel axis;

(d) second platform means having a surface, for providing support, the second platform means having a carrousel axis, the second platform means being connected to the first platform means within the opening, the carrousel axis being substantially perpendicular to the first sensing axis of the first rate-gyro means;

(e) second two-degree-of-freedom rate-gyro means located on the surface of the second platform, the second rate-gyro means having a first sensing axis that is substantially alignable with said first sensing axis of the first rate-gyro means and having a second sensing axis orthogonal to the two sensing axes of the first rate-gyro means, for sensing for rotation; and

(f) means for carrouseling the second platform means around its carrousel axis; and

(g) computer means for calculating a drift rate of the first sensing axis of the first rate-gyro means from a signal from the first sensing axis of the first rate-gyro means, a signal from the first sensing axis of the second rate-gyro means, and a signal from the first sensing axis of the second rate-gyro means after the second platform means is carrouseled 180

5. An inertial platform case unit for a vehicle, the vehicle having a vehicle rotation axis, the inertial platform case unit comprising:

(a) case means mountable to the vehicle;

(b) a first platform within the case means, the first platform having a plane and an opening, and being carrouselable around a first carrousel axis, the first carrousel axis located along the vehicle rotation axis;

(c) first gyro means located on the plane of the first platform and having a sensing axis parallel to the first carrousel axis, for sensing for rotation of the vehicle around the vehicle rotation axis;

(d) a second platform having a surface, the second platform being connected to the first platform within the opening of the first platform, the second platform being carrouselable around a second carrousel axis, the second carrousel axis being in the plane of the first platform and perpendicular to the first carrousel axis;

(e) second gyro means located on the surface of the second platform and having a sensing axis parallel to the carrousel axis of the first platform, for sensing for rotation of the vehicle around the vehicle rotation axis;

(f) carrousel means for carrouseling the second platform means around its carrousel axis; and

(g) computer means for calculating a drift rate of the sensing axis of the first gyro means from a signal from the sensing axis of the first gyro means, a signal from the sensing axis of the second gyro means, and a signal from the sensing axis of the second gyro means after the second platform is carrouseled 180 degrees.

6. The inertial platform case unit of claim 5 wherein the first gyro means has a spin axis, the spin axis of the first gyro means being perpendicular to the first carrousel axis, the spin axis of the first gyro means also being parallel to the plane of the first platform, the first gyro having first drift characteristics, and wherein the second gyro means has a spin axis, the spin axis of the second gyro means being perpendicular to the plane of the second platform, the second gyro means having second drift characteristics.

7. The inertial platform case unit of claim 6 wherein the first gyro means is a two-degree-of-freedom gyro and wherein the second gyro means is a two-degree-of-freedom gyro.

8. The inertial platform case unit of claim 6 and further comprising a vehicle having said vehicle rotation axis.

9. The inertial platform case unit of claim 7 and further comprising a vehicle having said vehicle rotation axis.

10. The inertial platform case unit of claim 5 and further comprising a vehicle having said vehicle rotation axis.