Spherical position monitoring system

• US 7,340,344 B2
• Filed: 12/03/2004
• Issued: 03/04/2008
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Chappell, Charles D.
• Primary Examiner(s): Zanelli; Michael J.
• Application Number:
  US11/004,531
• Publication Number:
  US 20060058946A1
• Time in Patent Office: 1,187 Days
• Field of Search: None
• US Class Current: 701/220
• CPC Class Codes: G01C 21/166 Mechanical, construction or arrangement details of inertial navigation systems
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01D 5/347 using displacement encoding scales
• CPC Class Codes: G01P 3/36 Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light G01P3/68 takes precedence; gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams G01C19/64

Abstract

A contact free optical position sensor for an inertial reference system. The surface of an inertial sensor assembly is adapted with a coordinate encoded pattern. One or more optical sensors are adapted to generate image signals of the coordinate encoded pattern of the spherical inertial sensor assembly. A controller is coupled to receive the image signals from the optical sensors and adapted to apply a decoding algorithm to each image signal. The decoding algorithm determines the coordinates of the inertial sensor assembly images captured by each optical sensor and calculates the angular position of the inertial sensor assembly.

Claims

1. A position detection system for a sphere comprising:

one or more optical sensors adapted to generate image signals of a coordinate encoded surface pattern on a spherical object; and

a controller coupled to receive the image signals from the one or more optical sensors, the controller having a decoding algorithm adapted to determine the surface location of the sphere based on one or more imaged surface patterns in the image signals;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the decoding algorithm determines the location of the surface of the sphere from the one or more images of surface patterns by measuring the thickness of intersecting first series and second series lines.

2. The position detection system of claim 1, wherein the controller is further adapted to calculate the angular position of the sphere.

3. The position detection system of claim 2, further comprising:

one or more housings, each optical sensor located in an associated housing.

4. The position detection system of claim 3, further comprising:

a solid mounting surface, each housing attached to the solid mounting surface.

5. The position detection system of claim 4, wherein the controller is located in one of the housings.

6. The position detection system of claim 2, wherein the spherical object is a spherical inertial sensor assembly for an inertial navigation system.

7. The position detection system of claim 1, wherein the decoding algorithm further determines the location of the surface of the spherical object from the one or more images of surface patterns by measuring the rotational angle of the lines appearing in the image signals.

8. The position detection system of claim 1, wherein the double circle series pattern includes a first series of circles defining a series of meridian lines and a second series of circles defining a series of parallel lines.

9. The position detection system of claim 1, wherein the double circle series pattern includes a first series of circles defining a series of meridian lines and a second series of circles defining a series of meridian lines.

10. The position detection system of claim 1, wherein the double circle series pattern includes a first series of circles defining a series of parallel lines and a second series of circles defining a series of parallel lines.

11. An angular position detection apparatus comprising:

an inertial navigation system including a gas bearing supported spherical inertial sensor assembly, said spherical inertial sensor having a coordinate encoded pattern thereon;

one or more optical sensors adapted to generate image signals of the coordinate encoded pattern on the spherical inertial sensor assembly; and

a controller coupled to receive the image signals from the one or more optical sensors, the controller having a decoding algorithm adapted to determine the surface location of the spherical inertial sensor assembly based on one or more imaged surface patterns in the image signals;

wherein the controller is further adapted to calculate the angular position of the spherical inertial sensor assembly;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the decoding algorithm determines the coordinates of the surface of the spherical inertial sensor assembly captured in the image signals by each optical sensor by measuring the thickness of intersecting lines, and the rotational angle of the lines appearing in the image signals.

12. The position detection system of claim 11:

an outer shell assembly enveloping the spherical inertial sensor assembly, the optical sensors attached to the outer shell assembly.

13. An angular position detection apparatus comprising:

an inertial navigation system including a gas bearing supported spherical inertial sensor assembly, said spherical inertial sensor having a coordinate encoded pattern thereon;

one or more optical sensors adapted to generate image signals of the coordinate encoded pattern on the spherical inertial sensor assembly; and

a controller coupled to receive the image signals from the one or more optical sensors, the controller having a decoding algorithm adapted to determine the surface location of the spherical inertial sensor assembly based on one or more imaged surface patterns in the image signals;

wherein the controller is further adapted to calculate the angular position of the spherical inertial sensor assembly;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern includes a first series of circles defining a series of meridian lines and a second series of circles defining a series of parallel lines.

14. An angular position detection apparatus comprising:

an inertial navigation system including a gas bearing supported spherical inertial sensor assembly, said spherical inertial sensor having a coordinate encoded pattern thereon;

one or more optical sensors adapted to generate image signals of the coordinate encoded pattern on the spherical inertial sensor assembly; and

a controller coupled to receive the image signals from the one or more optical sensors, the controller having a decoding algorithm adapted to determine the surface location of the spherical inertial sensor assembly based on one or more imaged surface patterns in the image signals;

wherein the controller is further adapted to calculate the angular position of the spherical inertial sensor assembly;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern includes a first series of circles defining a series of meridian lines and a second series of circles defining a series of meridian lines.

15. An angular position detection apparatus comprising:

an inertial navigation system including a gas bearing supported spherical inertial sensor assembly, said spherical inertial sensor having a coordinate encoded pattern thereon;

one or more optical sensors adapted to generate image signals of the coordinate encoded pattern on the spherical inertial sensor assembly; and

a controller coupled to receive the image signals from the one or more optical sensors, the controller having a decoding algorithm adapted to determine the surface location of the spherical inertial sensor assembly based on one or more imaged surface patterns in the image signals;

wherein the controller is further adapted to calculate the angular position of the spherical inertial sensor assembly;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern includes a first series of circles having lines of a different color than a second series of circles.

16. An angular position detection apparatus comprising:

an inertial navigation system including a gas bearing supported spherical inertial sensor assembly, said spherical inertial sensor having a coordinate encoded pattern thereon;

one or more optical sensors adapted to generate image signals of the coordinate encoded pattern on the spherical inertial sensor assembly; and

a controller coupled to receive the image signals from the one or more optical sensors, the controller having a decoding algorithm adapted to determine the surface location of the spherical inertial sensor assembly based on one or more imaged surface patterns in the image signals;

wherein the controller is further adapted to calculate the angular position of the spherical inertial sensor assembly;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern includes a first series of circles having lines of a different style than a second series of circles.

17. A method for determining the angular position of an inertial sensor assembly, the method comprising:

applying a coordinate encoded pattern to the surface of the inertial sensor assembly;

simultaneously capturing one or more images of the inertial sensor assembly, where each image captures a different surface location on the inertial sensor assembly;

calculating the angular position of the inertial sensor assembly based on the surface location and rotational angles in the captured images; and

looking up the captured intersecting lines in a table to determine the surface locations of the points of intersection.

18. A method for determining the angular position of an inertial sensor assembly, the method comprising:

simultaneously capturing a first image of the inertial sensor assembly and a second image of the inertial sensor assembly, where the first image and second image capture different locations on the surface of the inertial sensor assembly;

analyzing the first image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the first image;

analyzing the second image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the second image;

calculating the angular position of the inertial sensor assembly based on the surface location and rotational angles in the captured images;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern further comprises a first circle series having lines of a different color from a second circle series.

19. A method for determining the angular position of an inertial sensor assembly, the method comprising:

simultaneously capturing a first image of the inertial sensor assembly and a second image of the inertial sensor assembly, where the first image and second image capture different locations on the surface of the inertial sensor assembly;

analyzing the first image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the first image;

analyzing the second image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the second image;

calculating the angular position of the inertial sensor assembly based on the surface location and rotational angles in the captured images;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern further comprises a first circle series having different style lines from a second circle series.

20. A method for determining the angular position of an inertial sensor assembly, the method comprising:

simultaneously capturing a first image of the inertial sensor assembly and a second image of the inertial sensor assembly, where the first image and second image capture different locations on the surface of the inertial sensor assembly;

analyzing the first image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the first image;

analyzing the second image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the second image;

recognizing intersecting lines in the coordinate encoded pattern captured in the first and second images; and

measuring the respective thickness of the intersecting lines and the rotational angle of the intersecting lines appearing in the images.

21. The method of claim 20, wherein analyzing the first image and second image to decode the coordinate encoded pattern imaged further comprises:

comparing the measured widths of the respective lines with widths stored in a table.

22. The method of claim 20, wherein analyzing the first image and second image to decode the coordinate encoded pattern imaged further comprises:

determining the respective colors of the intersecting lines appearing in the first image and second image.

23. The method of claim 22, wherein analyzing the first image and second image to decode the coordinate encoded pattern imaged further comprises:

comparing the widths and colors of the respective lines with widths and colors stored in a table.

24. The method of claim 20, wherein analyzing the first image and second image to decode the coordinate encoded pattern imaged further comprises:

determining the respective style of the intersecting lines appearing in the image signal.

25. The method of claim 23, wherein analyzing the first image and second image to decode the coordinate encoded pattern imaged further comprises:

comparing the widths and styles of the respective lines with widths and colors stored in a table.

26. A method for determining the angular position of an inertial sensor assembly, the method comprising:

simultaneously capturing a first image of the inertial sensor assembly and a second image of the inertial sensor assembly, where the first image and second image capture different locations on the surface of the inertial sensor assembly;

analyzing the first image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the first image;

analyzing the second image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the second image;

calculating the angular position of the inertial sensor assembly based on the surface location and rotational angles in the captured images;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern includes a first series of circles defining a series of meridian lines and a second series of circles defining a series of parallel lines.

27. A method for determining the angular position of an inertial sensor assembly, the method comprising:

simultaneously capturing a first image of the inertial sensor assembly and a second image of the inertial sensor assembly, where the first image and second image capture different locations on the surface of the inertial sensor assembly;

analyzing the first image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the first image;

analyzing the second image to decode the coordinate encoded pattern imaged and to determine the location and rotational angle of the inertial sensor assembly appearing in the second image;

calculating the angular position of the inertial sensor assembly based on the surface location and rotational angles in the captured images;

wherein the coordinate encoded surface pattern includes a double circle series pattern; and

wherein the double circle series pattern includes a first series of circles defining a series of meridian lines and a second series of circles defining a series of meridian lines.