Airborne widefield airspace imaging and monitoring

• US 8,494,760 B2
• Filed: 12/14/2010
• Issued: 07/23/2013
• Est. Priority Date: 12/14/2009
• Status: Active Grant

• Current Assignee: American Aerospace Advisors, Inc.
• Original Assignee: American Aerospace Advisors, Inc.
• Inventors: Yoel, David William, Littlefield, John E., Hill, Robert Duane
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): MELTON, TODD M
• Application Number:
  US12/967,718
• Publication Number:
  US 20110184647A1
• Time in Patent Office: 952 Days
• Field of Search: 701/301, 385/117, 385/120, 348/36, 348/359
• US Class Current: 701/301
• CPC Class Codes: G08G 5/0021 located in the aircraft
• CPC Class Codes: G08G 5/0069 specially adapted for an unmanned aircraft
• CPC Class Codes: G08G 5/0078 for monitoring traffic from the aircraft radar or analogous systems specially adapted for traffic control G01S13/91

Abstract

A Widefield Airspace Imaging and Navigation System to provide UASs with wide field airspace imaging and collision avoidance capabilities. An array of optical lenses are distributed throughout the aircraft to provide an unobstructed view in all directions around the aircraft. Each collection lens is coupled through an optical fiber to a camera that multiplexes the several images. A processing system is connected to the wide array imaging system, and it runs an image interpolation program for resolving a background image and for distinguishing objects that are not moving with the background. In addition, a navigation control program reads the image interpolation software and, upon detection of an approaching object, implements a rule-based avoidance maneuver by sending an appropriate signal to the existing UAS autopilot.

Claims

1. A widefield airspace imaging and monitoring system for imaging the airspace around an unmanned aerial vehicle having a right-side wing, a left-side wing, and an autopilot system, comprising:

a digital camera mounted within said vehicle, said camera having a digital image sensor;

a plurality of stationary collection lenses mounted in a distributed array about the vehicle and oriented in a plurality of angular orientations, said plurality of stationary collection lenses further consisting of six (6) collection lenses, a first lens being mounted on a leading upward distal tip of the right-side wing of said vehicle, a second lens mounted on an aft upward distal tip of the right-side wing of said vehicle, a third lens mounted on a leading downward distal tip of the right-side wing of said vehicle, a fourth lens mounted on a leading upward distal tip of a left-side wing of said vehicle, a fifth lens mounted on an aft upward distal tip of a left-side wing of said vehicle, and a sixth lens mounted on a leading downward distal tip of a left-side wing of said vehicle, each of said plurality stationary collection lenses having a pre-determined 112 degree field of view, said angular orientations being calculated so that the field of view of each of said plurality stationary collection lenses overlaps with the field of view of another of said plurality stationary collection lenses; and

a plurality of optical fiber image transfer devices each connected at one end to a corresponding one of said plurality of stationary collection lenses;

a mechanical mount connected to the other end of said plurality of optical fibers in such a way so as to project the images captured by each of said plurality stationary collection lenses onto adjacent defined subareas of said digital camera image sensor, thereby forming a mosaic of narrow-field images resolved by said camera into a wide field image of the airspace surrounding the vehicle; and

a processor and memory for storing software and image data comprising a plurality of sequential frames of said wide field image of the airspace surrounding the vehicle; and

software comprising computer instructions stored on non-transitory memory for carrying out the steps of,

resolving a background image moving at a constant rate within said image data,

distinguishing an object within said image data that is not moving with the background image,

determining a rate at which said object changes its position,

determining that an avoidance measure is needed to avoid colliding with said object, and

communicating to said autopilot that said avoidance measure is needed.

2. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 1, wherein said software for carrying out the step of deciding when avoidance measures are needed further comprises a collision target extraction software module for interfacing between the image interpolation software module and an existing UAS autopilot system for rule-based avoidance maneuver decision making based on said determined rate at which said object changes its position.

3. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 1, wherein said mosaic of narrow-field images are resolved by said camera into a wide field image of a full 360 degree view of said airspace around the vehicle.

4. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 1, wherein the ends of said plurality of optical fibers connected to said mechanical mount are rectangular in cross section.

5. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 1, wherein said processor is a field-programmable gate array (FPGA)-based processor.

6. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 1, wherein said image interpolation software module distinguishes objects that are not moving within a background image by analyzing sequential image frames, identifying image features moving at a constant rate between sequential frames, and then identifying features moving at a different velocities than said constant rate within the defined background.

7. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 1, wherein said image interpolation software module sends a command to the UAS autopilot system for rule-based avoidance maneuver decision making.

8. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 7, wherein said command may be any one from among the group consisting of change direction, change speed, and change altitude.

9. A widefield airspace imaging and monitoring system for imaging the airspace around an unmanned aerial vehicle having a right-side wing, a left-side wing, and an autopilot system, comprising:

a digital camera mounted within said vehicle, said camera having a digital image sensor;

a plurality of stationary collection lenses mounted in a distributed array about the vehicle and oriented in a plurality of angular orientations, said plurality of stationary collection lenses further consisting of six (6) stationary collection lenses including a first lens mounted on a leading upward distal tip of the right-side wing of said vehicle, a second lens mounted on an aft upward distal tip of the right-side wing of said vehicle, a third lens mounted on a leading downward distal tip of the rightside wing of said vehicle, a fourth lens mounted on a leading upward distal tip of a leftside wing of said vehicle, a fifth lens mounted on an aft upward distal tip of a left-side wing of said vehicle, and a sixth lens mounted on a leading downward distal tip of a left-side wing of said vehicle, each of said plurality stationary collection lenses having a pre-determined 64 degree field of view, said angular orientations being calculated so that the field of view of each of said plurality stationary collection lenses overlaps with the field of view of another of said plurality stationary collection lenses;

a plurality of optical fiber image transfer devices each connected at one end to a corresponding one of said plurality of stationary stationery collection lenses;

a mechanical mount connected to the other end of said plurality of optical fibers in such a way so as to project the images captured by each of said plurality of collection lenses onto adjacent defined subareas of said digital camera image sensor, thereby forming a mosaic of narrow-field images resolved by said camera into a wide field image of the airspace surrounding the vehicle;

a processor and memory for storing software and image data comprising a plurality of sequential frames of said wide field image of the airspace surrounding the vehicle; and

software comprising computer instructions stored on non-transitory memory for carrying out the steps of,

resolving a background image within said image data,

distinguishing an object within said image data that is not moving with the background image,

determining a rate at which said object changes its position,

deciding that an avoidance measure is needed to avoid colliding with said object based on said change in position, and

communicating to said autopilot that said avoidance measure is needed.

10. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 9, wherein said mosaic of narrow-field images are resolved by said camera into a wide field image of a 220 by 30 degree view of said airspace around the vehicle.

11. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 9, wherein said mechanical mount comprises a mounting block positioned to resolve the discrete images from each of said six (6) stationary collection lenses directly onto the imaging sensor of said camera.

12. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 11, wherein said digital camera imaging sensor comprises a 15 million pixel imaging sensor.

13. The widefield airspace imaging and monitoring system for imaging the airspace around a vehicle according to claim 12, wherein said mechanical mount comprises a mounting block positioned to resolve the discrete images from each of said six (6) stationary collection lenses into six defined 2.5 million pixel mosaics of said image sensor.

14. An airborne imaging system for monitoring airspace by a UAS vehicle having a right-side wing, a left-side wing, and an autopilot system, comprising:

a wide array imaging system, including,

a single high definition camera mounted within the vehicle,

an array of collection lenses distributed throughout the vehicle to provide a wide field of view from a plurality of narrower overlapping fields of view, said array of collection lenses further comprising six collection lenses, including three said collection lenses mounted at a tip of the right-side wing of said vehicle, and three said collection lenses mounted at a tip of the left-side wing of said vehicle, each of said plurality of stationary collection lenses having a pre-determined field of view equal to one of 64 degrees or 112 degrees and being mounted at an angular orientation calculated so that the field of view of each of said plurality stationary collection lenses overlaps with the field of view of another of said plurality of said stationary collection lenses;

a plurality of optical fiber image transfer devices each coupled to one of said collection lenses for conveying the discrete optical images there from,

a mechanical mount coupled to one end of said plurality of optical fibers for multiplexing the several images there from onto a single imaging sensor,

said imaging sensor having a plurality of predefined image areas each corresponding to one of said discrete optical images and collectively forming a mosaic wide field airspace image; and

a processing system connected to said wide array imaging system, said processing system including an image interpolation software program comprising computer instructions stored on non-transitory memory for carrying out the steps of,

resolving a background image within said wide field airspace image,

distinguishing an object that is not moving with the background image,

deciding that an avoidance measure is needed to avoid colliding with said object, and

communicating to said autopilot that said avoidance measures are needed.

15. The airborne imaging system for monitoring airspace according to claim 14, wherein said software further comprises a navigation control software program for interfacing between the image interpolation software program and an existing UAS autopilot system for performing said step of deciding that an avoidance measure is needed by rule-based avoidance maneuver decision making.

16. The airborne imaging system for monitoring airspace according to claim 14, wherein each of said plurality of stationary collection lenses has a pre-determined field of view equal to 64 degrees, and said multiplexing of the several images onto said single imaging sensor mosaic are resolved into a wide field image of a full 360 degree spherical view of said airspace around the vehicle.

17. The airborne imaging system for monitoring airspace according to claim 14, wherein each of said plurality of stationary collection lenses has a pre-determined field of view equal to 112 degrees, and said multiplexing of the several images onto said single imaging sensor mosaic are resolved into a wide field image of a subset of a 360 degree view of said airspace around the vehicle.

18. The airborne imaging system for monitoring airspace according to claim 14, wherein said camera is one of a frame camera for acquiring a sequence of individual images or a video camera for acquiring images at a high frame rate.

19. The airborne imaging system for monitoring airspace according to claim 18, wherein said camera acquires images in any one or more of the following segments of the light spectrum, comprising color, near infrared, short wave infrared, medium wave infrared or long wave infrared segments of the spectrum.