Optical-flow techniques for improved terminal homing and control

• US 8,686,326 B1
• Filed: 03/25/2009
• Issued: 04/01/2014
• Est. Priority Date: 03/26/2008
• Status: Active Grant

• Current Assignee: Arete Associates
• Original Assignee: Arete Associates
• Inventors: Dennison, John C., Campion, David C.
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US12/383,638
• Time in Patent Office: 1,833 Days
• Field of Search: 244 31- 33, 701 1- 18, 701/23, 701/27, 701/28, 701/400, 701/408, 701300-302, 102/206, 102/211, 102/213, 342 52- 55, 342 61- 66, 342/175, 342/195, 342 70- 72, 180167-169, 367/87, 367 95-105, 382100-107
• US Class Current: 244/3.16
• CPC Class Codes: F41G 7/2246 Active homing systems, i.e. comprising both a transmitter and a receiver
• CPC Class Codes: F41G 7/2253 Passive homing systems, i.e. comprising a receiver and do not requiring an active illumination of the target
• CPC Class Codes: F41G 7/2286 using radio waves
• CPC Class Codes: F41G 7/2293 using electromagnetic waves other than radio waves
• CPC Class Codes: F42B 15/01 Arrangements thereon for guidance or control steering arrangements F42B10/60; aircraft flight control B64C; guidance systems other than those installed aboard F41G7/00, F41G9/00; locating by use of radio or other waves G01S; flight control in general G05D1/00; computer aspects G06]
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/3602 Input other than that of destination using image analysis, e.g. detection of road signs, lanes, buildings, real preceding vehicles using a camera
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 3/784 using a mosaic of detectors
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30212 Military
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/269 using gradient-based methods
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80

Abstract

In certain aspects, this invention is a “control system” that detects and minimizes (or otherwise optimizes) an angle between vehicle centerline (or other reference axis) and vehicle velocity vector—as for JDAM penetration. Preferably detection is exclusively by optical flow (which herein encompasses sonic and other imaging), without data influence by navigation. In other aspects, the invention is a “guidance system”, with optical-flow subsystem to detect an angle between the vehicle velocity vector and line of sight to a destination—either a desired or an undesired destination. Here, vehicle trajectory is adjusted in response to detected angle, for optimum angle, e.g. to either home in on a desired destination or avoid an undesired destination (or rendezvous), and follow a path that'"'"'s ideal for the particular mission—preferably by controlling an autopilot or applying information from navigation. Purposes include real-time angle optimization to improve autopilots or guidance, and vehicle development or testing.

Claims

1. A control system, for controlling a vehicle that has a reference axis and that while in motion has a velocity vector, said control system comprising:

an optical-flow subsystem detecting an angle between such reference axis and such velocity vector; and

a vehicle orientation-adjustment subsystem responding to the detected angle, to optimize the detected angle.

2. The control system of claim 1, wherein:

said other subsystem optimizes said angle by adjusting orientation of the reference axis.

3. A control system, for controlling a vehicle that has a reference axis and that while in motion has a velocity vector, said control system comprising:

an optical-flow subsystem detecting an angle between such reference axis and such velocity vector; and

another subsystem responding to the detected angle by modifying said angle;

wherein said other subsystem does not use information from any navigation apparatus or algorithm for responding to the detected angle by modifying said angle.

4. A control system, for controlling a vehicle that has a reference axis and that while in motion has a velocity vector, said control system comprising:

an optical-flow subsystem detecting an angle between such reference axis and such velocity vector; and

another subsystem responding to the detected angle by modifying said angle;

wherein said other subsystem comprises means for providing data from the control system to an autopilot system to guide the vehicle on a terminal path.

5. The control system of claim 4, wherein:

the terminal path is a specific, precise path.

6. The control system of claim 4, wherein:

said other subsystem modifies said angle by adjusting orientation of the reference axis.

7. A control system, for controlling a vehicle that has a reference axis and that while in motion has a velocity vector, said control system comprising:

an optical-flow subsystem detecting an angle between such reference axis and such velocity vector; and

another subsystem responding to the detected angle by modifying said angle;

wherein the vehicle comprises a parachute, or another airborne gliding device.

8. The control system of claim 7, wherein the vehicle comprises one or more of:

a paratrooper or rescue dog, or other living being; and

a module for carrying a payload.

9. The control system of claim 7, wherein:

said other subsystem modifies said angle by adjusting orientation of the reference axis.

10. A guidance system, for controlling a vehicle that has a destination and that while in motion has a velocity vector, said guidance system comprising:

an optical-flow subsystem detecting an angle between such velocity vector and a line of sight to such destination; and

a vehicle trajectory-adjustment subsystem responding to the detected angle, to modify the velocity vector so as to optimize the detected angle.

11. The guidance system of claim 10, wherein:

the trajectory-adjustment subsystem does not use information from any navigation apparatus or algorithm for responding to the detected angle, to modify the velocity vector so as to optimize the detected angle.

12. The guidance system of claim 10, wherein the trajectory-adjustment subsystem comprises:

means for minimizing the detected angle.

13. The guidance system of claim 10, wherein the trajectory-adjustment subsystem comprises:

means for applying information from a navigation unit or algorithm, in optimizing the detected angle.

14. The guidance system of claim 10, wherein the vehicle has a mission of destruction or rendezvous or avoidance, or any other particular type of mission, and the trajectory-adjustment subsystem comprises:

means for modifying the vector to provide a path to the destination.

15. The guidance system of claim 14, particularly for use while such vehicle approaches such destination, and wherein the optical-flow subsystem comprises:

an imaging unit secured to the vehicle; and

means for causing the imaging unit to form a succession of images of such destination; and

means for receiving and analyzing the succession of images.

16. The guidance system of claim 15, wherein the imaging unit comprises one or more of:

a camera;

a radar, lidar or ladar module;

or an IR imager or other electrooptical imager; and

a sonar module.

17. The guidance system of claim 10, wherein:

the vehicle comprises a controlled-movement device such as a parachute or another airborne gliding device.

18. The guidance system of claim 17, wherein the vehicle comprises one or more of:

a paratrooper or rescue dog, or other living being; and

a module for carrying a payload.

19. The guidance system of claim 10, particularly for use as such vehicle approaches a destination region, and wherein the optical-flow subsystem comprises:

an imaging unit secured to the vehicle;

means for causing the imaging unit to form a succession of images of such destination region; and

means for receiving and analyzing the succession of images.

20. The guidance system of claim 19, wherein:

the imaging unit comprises a camera.

21. The guidance system of claim 19, wherein the imaging unit comprises one or more of:

a radar, lidar or ladar module;

or a sonar module;

or an IR imager or other electrooptical imager.

22. The guidance system of claim 19, wherein the receiving means comprise one or more of:

a multipurpose digital processor;

a field-programmable gate array; and

analog circuits.

23. The guidance system of claim 10, particularly for an airborne vehicle and further comprising:

an autopilot controlled by the orientation-adjustment subsystem.

24. The guidance system of claim 10, particularly for an airborne vehicle that is a penetrating munition, and wherein:

the orientation-adjustment subsystem extends depth of penetration of the munition.

25. The guidance system of claim 10, particularly for a ground vehicle and further comprising:

an autopilot controlled by the orientation-adjustment subsystem.

26. A guidance system, for controlling a vehicle that operates in relation to another object or to a particular undesired destination, and that while in motion has a velocity vector, said guidance system comprising:

an optical-flow subsystem detecting an angle between such velocity vector and a line of sight to such other object or particular destination; and

a vehicle trajectory-adjustment subsystem responding to the detected angle, to modify the velocity vector so as to optimize the detected angle for avoidance of the other object or particular undesired destination.

27. A guidance system for guiding a vehicle that is under engineering development or testing, or both;

or that is for operation with an autopilot or a guidance algorithm, or both;

or is under combinations of these circumstances; and

that while in motion has a velocity vector, said guidance system comprising;

an optical-flow subsystem detecting an angle between such velocity vector and a line of sight to another object, or to a particular destination that is either desired or to be avoided; and

another subsystem responding to the detected angle—

to report or modify, or both, the velocity vector so as to;

optimize the detected angle for real-time measurement input to improve performance and robustness of such autopilot or such guidance algorithm, or both, or guide such engineering development or testing of air vehicles, or both.

28. A control system, for controlling a vehicle that has a reference axis and that while in motion has a velocity vector, said control system comprising:

an optical-flow subsystem detecting an angle between such reference axis and such velocity vector; and

another subsystem responding to the detected angle, to modify said angle.

29. The control system of claim 28, wherein:

the reference axis is a centerline of the vehicle.

30. The control system of claim 28, wherein:

said other subsystem comprises means for minimizing the detected angle.

31. The control system of claim 28, wherein:

said other subsystem comprises means for adjusting the detected angle to a specific value or range of values.

32. The control system of claim 28, particularly for use as such vehicle approaches a destination region, and wherein the optical-flow subsystem comprises:

an imaging unit secured to the vehicle;

means for causing the imaging unit to form a succession of images of such destination region; and

means for receiving and analyzing the succession of images.

33. The control system of claim 32, wherein:

the imaging unit comprises a camera.

34. The control system of claim 32, wherein the imaging unit comprises one or more of:

a radar, lidar or ladar module;

or a sonar module;

or an IR imager or other electrooptical imager.

35. The control system of claim 32, wherein the receiving means comprise one or more of:

a multipurpose digital processor;

a field-programmable gate array; and

analog circuits.

36. The control system of claim 28, particularly for an airborne vehicle and further comprising:

an autopilot controlled by the other subsystem.

37. The control system of claim 28, particularly for an airborne vehicle that is a penetrating munition, and wherein:

said other subsystem extends depth of penetration of the munition.

38. The control system of claim 28, particularly for a ground vehicle and further comprising:

an autopilot controlled by said other subsystem.

39. The control system of claim 28, wherein:

said other subsystem modifies said angle by adjusting orientation of the reference axis.

40. The control system of claim 28, wherein:

said other subsystem also comprises means for recording the detected angle, or transmitting the detected angle, or both.