FIELD INTERCHANGABLE BORESIGHT MOUNTING SYSTEM AND CALIBRATION METHOD

• US 20130139566A1
• Filed: 12/04/2012
• Published: 06/06/2013
• Est. Priority Date: 12/06/2011
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Storch, David Robert, Jones, Ralph R., Weed, Douglas Mark
• Granted Patent: US 9,182,211 B2
• Time in Patent Office: Days
• US Class Current: 73/1.75
• CPC Class Codes: F41G 3/32 Devices for testing or checking
• CPC Class Codes: G01B 5/25 for testing the alignment of axes
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices

Abstract

A calibration method comprises providing a mounting fixture including a tray coupled to a frame, and an alignment measurement sensor removably coupled to the tray. An angular orientation of the tray is determined using the alignment measurement sensor removably coupled to the tray in a first position. The alignment measurement sensor is then moved to a second position on the tray that is rotated from the first position, and the angular orientation of the tray is determined using the alignment measurement sensor at the second position. An axis misalignment for at least two of a pitch axis, a roll axis, or a yaw axis of the alignment measurement sensor is then calculated to determine one or more misalignment factors. The one or more misalignment factors are then applied to correct for misalignment of the alignment measurement sensor.

Claims

1. A calibration method, comprising:

providing a mounting fixture including a tray coupled to a frame, and an alignment measurement sensor removably coupled to the tray;

determining an angular orientation of the tray using the alignment measurement sensor removably coupled to the tray in a first position;

moving the alignment measurement sensor to a second position on the tray that is rotated from the first position;

determining the angular orientation of the tray using the alignment measurement sensor at the second position;

calculating an axis misalignment for at least two of a pitch axis, a roll axis, or a yaw axis of the alignment measurement sensor to determine one or more misalignment factors; and

applying the one or more misalignment factors to correct for misalignment of the alignment measurement sensor.

2. The method of claim 1, further comprising:

moving the alignment measurement sensor back to the first position at least once from the second position;

determining an average of data measurements taken by the alignment measurement sensor and whether a current position of the alignment measurement sensor is within repeatability bounds;

if a resulting variation of the current position is within repeatability bounds, the average of the measurements is used as the misalignment factor; and

if the resulting variation is outside of acceptable repeatability bounds, the measurements are rejected.

3. The method of claim 1, wherein the alignment measurement sensor comprises a boresighting device.

4. The method of claim 1, wherein each axis misalignment is calculated using a weighted value for each data measurement at a given position.

5. The method of claim 2, wherein if the current position is not within repeatability bounds, the method further comprising:

determining whether a predetermined number of iterations is exceeded;

if the predetermined number of iterations is not exceeded, moving the alignment measurement sensor to the second position; and

determining whether a then current position of the alignment measurement sensor is within repeatability bounds.

6. The method of claim 1, wherein the misalignment factors are applied to output angles of the alignment measurement sensor.

7. The method of claim 1, wherein the misalignment factors are applied to correct an alignment algorithm for the alignment measurement sensor by starting the alignment algorithm using the misalignment factors.

8. The method of claim 1, further comprising providing one or more angular offset measurement devices coupled to the tray.

9. The method of claim 1, wherein the mounting fixture further includes an adapter that removably couples the alignment measurement sensor to the tray.

10. The method of claim 9, further comprising providing one or more angular offset measurement devices mounted on the adapter.

11. The method of claim 1, further comprising providing a frame movement sensor affixed to the tray.

12. The method of claim 11, wherein the frame movement sensor comprises a boresighting device.

13. A boresight mounting system, comprising:

a mounting fixture comprising a tray having an outer surface and configured to be attached to a frame;

a frame movement sensor affixed to the outer surface of the tray, the frame movement sensor configured to determine attitude measurement changes of the tray; and

an alignment measurement sensor removably coupled to the outer surface of the tray, the alignment measurement sensor configured to determine a first reference position of the tray while the alignment measurement sensor is at a first position and orientation, the alignment measurement sensor configured to determine a second reference position of the tray when the alignment measurement sensor is at a second position and orientation that is rotated from the first position and orientation.

14. The system of claim 13, further comprising one or more angular offset measurement devices coupled to the outer surface of the tray.

15. The system of claim 13, wherein the mounting fixture further comprises an adapter that removably couples the alignment measurement sensor to the tray.

16. The system of claim 15, further comprising one or more angular offset measurement devices mounted on the adapter.

17. The system of claim 13, wherein the frame movement sensor comprises a boresighting device.

18. The system of claim 13, wherein the alignment measurement sensor comprises a boresighting device.

19. A computer program product, comprising:

a non-transitory computer readable medium having instructions stored thereon executable by a processor to perform a calibration method, comprising;

determining an angular orientation of a tray coupled to a frame based on data from a frame alignment measurement sensor removably coupled to the tray in a first position and orientation;

determining the angular orientation of the tray based on data from the alignment measurement sensor after being moved to a second position and orientation on the tray that is spaced apart and rotated from the first position and orientation;

calculating an axis misalignment for at least two of a pitch axis, a roll axis, or a yaw axis of the alignment measurement sensor to determine one or more misalignment factors; and

applying the one or more misalignment factors to output angles of the frame alignment measurement sensor to correct for misalignment of the frame alignment measurement sensor.