Auto-alignment system for high precision masted head mirror

• US 9,404,792 B2
• Filed: 07/01/2013
• Issued: 08/02/2016
• Est. Priority Date: 07/01/2013
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Shimon, Philip T., Cook, Lacy G., Robinson, Brendan H.
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): Wyatt, Kevin
• Application Number:
  US13/932,921
• Publication Number:
  US 20150001381A1
• Time in Patent Office: 1,128 Days
• Field of Search: 250/206.1, 250/216
• US Class Current: 1/1
• CPC Class Codes: F41G 3/22 for vehicle-borne armament, e.g. on aircraft
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures
• CPC Class Codes: G01C 11/025 by scanning the object
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G02B 23/08 Periscopes arrangements on floating structures of underwater viewing devices B63C11/49; arrangement of visual watch equipment on submarines B63G8/38
• CPC Class Codes: G02B 27/64 Imaging systems using optical elements for stabilisation of the lateral and angular position of the image
• CPC Class Codes: G02B 27/644 compensating for large deviations, e.g. maintaining a fixed line of sight while a vehicle on which the system is mounted changes course
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• CPC Class Codes: G02B 27/648 for automatically maintaining a reference alignment, e.g. in self-levelling surveying instruments surveying instruments per se G01C

Abstract

According to an embodiment of the disclosure, an optical sensor system comprises a mast, a mast mirror, a navigation unit, one or more faceted mirrors, and at least two beam-steering mirrors. The mast is elevated from a vehicle. The mast mirror reflects signals either to or from object space along a line of sight. The navigation unit determines a location and attitude of the mast mirror. The one or more faceted mirrors reflect an error sensing beam to reveal a flexure of the mast mirror. The at least two beam-steering mirrors prevent the line of sight for the signals reflected off the mast mirror from walking off the mast mirror by adjusting an angle and translation of the signals reflected off the mast mirror.

Claims

1. An optical sensor system comprising:

a mast configured to be elevated from a vehicle;

a mast mirror configured to reflect signals to or from object space along a line of sight, the mast mirror positioned on top of the mast;

a navigation unit configured to determine a location and attitude of the mast mirror;

one or more faceted mirrors configured to reflect an error sensing beam, the reflected error sensing beam revealing a flexure of the mast mirror, each of the one or more faceted mirrors having a plurality of facets; and

at least two beam-steering mirrors configured to prevent the line of sight for the signals reflected off the mast mirror from walking off the mast mirror by adjusting an angle and translation of the signals reflected off the mast mirror, the adjustment of the at least two beam-steering mirrors based on the reflected error sensing beam;

wherein the optical sensor system is configured such that angular movement of the mast mirror due to the flexure of the mast mirror causes the error sensing beam to translate from one of the facets to another of the facets.

2. The system of claim 1, wherein the mast is configured to be elevated from a ground vehicle.

3. The system of claim 2, further comprising:

one or more sensors configured to analyze the signals from object space, the one or more sensors configured to be positioned inside the ground vehicle.

4. The system of claim 3, wherein the one or more sensors are changeable with a new sensor configured to re-use the mast and mast mirror.

5. The system of claim 1, wherein:

the navigation unit comprises at least one accelerometer and at least one gyroscope; and

the system further comprises a global positioning system (GPS) unit co-located with the navigation unit.

6. The system of claim 1, wherein the signals include a laser beam that is reflected to object space along the line of sight.

7. The system of claim 6, further comprising:

a range finder configured to be pumped in a same optical path as the laser beam.

8. The system of claim 6, wherein the optical sensor system is configured to propagate the error sensing beam along a same path as the laser beam from the beam-steering mirrors to the mast mirror.

9. The system of claim 1, further comprising:

a range finder with a pulsed laser configured to calculate an internal range fluctuation with a corner cube at the mast mirror or with the mast mirror.

10. An optical sensor system comprising:

a mast configured to be elevated from a vehicle;

a mast mirror configured to reflect signals to or from object space along a line of sight, the mast mirror positioned on top of the mast, wherein the signals include a laser beam that is reflected to object space along the line of sight;

a navigation unit configured to determine a location and attitude of the mast mirror;

one or more faceted mirrors configured to reflect an error sensing beam, the reflected error sensing beam revealing a flexure of the mast mirror;

at least two beam-steering mirrors configured to prevent the line of sight for the signals reflected off the mast mirror from walking off the mast mirror by adjusting an angle and translation of the signals reflected off the mast mirror, the adjustment of the at least two beam-steering mirrors based on the reflected error sensing beam;

a range finder configured to be pumped in a same optical path as the laser beam; and

a range-finding fiber in each corner of the mast mirror.

11. An optical sensor system comprising:

a mast configured to be elevated from a vehicle;

a mast mirror configured to reflect signals to or from object space along a line of sight, the mast mirror positioned on top of the mast;

a navigation unit configured to determine a location and attitude of the mast mirror; and

one or more faceted mirrors configured to reflect an error sensing beam, the reflected error sensing beam revealing a flexure of the mast mirror, each of the one or more faceted mirrors having a plurality of facets;

wherein the optical sensor system is configured such that angular movement of the mast mirror due to the flexure of the mast mirror causes the error sensing beam to translate from one of the facets to another of the facets.

12. The system of claim 11, wherein the mast is configured to be elevated from a ground vehicle.

13. The system of claim 12, further comprising:

one or more sensors configured to analyze the signals from object space, the one or more sensors configured to be positioned inside the ground vehicle.

14. The system of claim 13, wherein the one or more sensors are changeable with a new sensor configured to re-use the mast and mast mirror.

15. The system of claim 11, wherein:

the navigation unit is an inertial measurement unit (IMU); and

the system further comprises a global positioning system (GPS) unit co-located with the IMU.

16. The system of claim 11, wherein the signals include a laser beam that is reflected to object space along the line of sight.

17. The system of claim 16, further comprising:

a range finder configured to be pumped in a same optical path as the laser beam.

18. The system of claim 16, further comprising:

a beam-steering mirror;

wherein the optical sensor system is configured to propagate the error sensing beam along a same path as the laser beam from the beam-steering mirror to the mast mirror.

19. The system of claim 11, further comprising:

a range finder with a pulsed laser configured to calculate an internal range fluctuation with a corner cube at the mast mirror or with the mast mirror.

20. An optical sensor system comprising:

a mast configured to be elevated from a vehicle;

a mast mirror configured to reflect signals to or from object space along a line of sight, the mast mirror positioned on top of the mast, wherein the signals include a laser beam that is reflected to object space along the line of sight;

a navigation unit configured to determine a location and attitude of the mast mirror;

one or more faceted mirrors configured to reflect an error sensing beam, the reflected error sensing beam revealing a flexure of the mast mirror;

a range finder configured to be pumped in a same optical path as the laser beam; and

a range-finding fiber in each corner of the mast mirror.