Laser-based speed determination device for use in a moving vehicle

• US 9,134,338 B2
• Filed: 11/05/2013
• Issued: 09/15/2015
• Est. Priority Date: 08/13/2007
• Status: Active Grant

• Current Assignee: Watchguard Video Incorporated (Motorola Solutions, Inc.)
• Original Assignee: Enforcement Video Incorporated (Enforcement Technology Group Incorporated)
• Inventors: Cilia, Andrew, Vanman, Robert V.
• Primary Examiner(s): RATCLIFFE, LUKE D
• Application Number:
  US14/072,518
• Publication Number:
  US 20140071284A1
• Time in Patent Office: 679 Days
• Field of Search: 356 301- 315, 356 401- 41, 356 501- 515, 356 6- 22, 356/28, 356/28.5
• US Class Current: 1/1
• 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
• CPC Class Codes: G01P 3/38 using photographic means
• CPC Class Codes: G01P 3/68 using optical means, i.e. using infrared, visible, or ultraviolet light G01P3/80 takes precedence ; by reflection of waves G01S17/58
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems

Abstract

A method of laser-based speed determination includes determining, via a digital scan of a field of view, a location of a target, directing, via a laser-aiming device, a laser from a laser device to the determined location, and determining a speed of the target via light reflected from the target to the laser device.

Claims

1. A method of laser-based speed determination, the method comprising:

determining, by a processor via a digital scan of a field of view, a location of a target;

directing, by the processor via a laser-aiming device in communication with the processor, a laser from a laser device to the determined location of the target;

determining a speed of the target via light reflected from the target to the laser device;

wherein, during at least a portion of each of the determining the location, the directing, and the determining the speed, the target and a laser-based speed-determination system are each independently in motion relative to a fixed point; and

wherein the determining the speed comprises detecting and considering ground speed of the laser-based speed-determination system.

2. The method of claim 1, further comprising displaying an annotated field of view, the annotated field of view comprising the field of view and the determined speed.

3. The method of claim 1, wherein:

the step of determining a location of a target comprises determining a location of a plurality of targets;

the directing step comprises directing, via the laser-aiming device, the laser to the determined location for each of the plurality of targets; and

the step of determining a speed of the target comprises determining a speed of the plurality of targets via light reflected from the plurality of targets to the laser device.

4. The method of claim 3, further comprising displaying an annotated field of view, the annotated field of view comprising the field of view and the determined speed for each of the plurality of targets.

5. The method of claim 1, wherein the laser-aiming device comprises a dual mirror system.

6. The method of claim 5, wherein the dual mirror system comprises a first mirror that permits aiming of the laser-aiming device in a horizontal direction and a second mirror that permits aiming of the laser-aiming device in a vertical direction.

7. The method of claim 1, wherein the laser-based speed-determination system comprises the processor and the laser-aiming device.

8. The method of claim 1, wherein:

the determined location of the target comprises a set of coordinates; and

the directing step comprises directing, via the laser-aiming device, the laser to the set of coordinates.

9. The method of claim 8, wherein the field of view comprises one or more images provided by a camera.

10. The method of claim 9, wherein the determining the location of the target comprises:

identifying an identifiable feature of a vehicle within the one or more images provided by the camera, the identifiable feature having a reflective surface; and

determining a set of coordinates for the identifiable feature.

11. The method of claim 10, wherein the identifiable feature is a license plate.

12. The method of claim 1, wherein the laser-aiming device comprises a device that pans and tilts.

13. The method of claim 6, wherein the first and second mirrors are attached to an electromechanical actuator.

14. The method of claim 1, wherein the laser-aiming device comprises a rotating mirror wheel having a plurality of mirror facets.

15. The method of claim 14, wherein:

vertical aim of the laser-aiming device is permitted by a change in angular orientation of the plurality of mirror facets as the rotating mirror wheel rotates; and

horizontal aim of the laser-aiming device is permitted by each of the plurality of mirror facets having a distinct horizontal inclination.

16. The method of claim 1, wherein the laser-aiming device comprises a single mirror mounted in a mechanical armature that pivots both horizontally and vertically.

17. The method of claim 1, further comprising calibrating the laser-aiming device according to the field of view.

18. A laser-based speed-determination system, the system comprising:

a laser device;

a laser-aiming device coupled to the laser device;

a processor in communication with the laser device and the laser-aiming device, the processor being adapted to execute instructions to;

determine, via a digital scan of a field of view, a location of a target;

cause, via the laser-aiming device, a laser to be directed from the laser device to the determined location of the target;

determine a speed of the target, the speed being determined via light reflected from the target to the laser device;

wherein, during at least a portion of each of the determination of the location, the direction of the laser, and the determination of the speed, the target and the laser-based speed-determination system are each independently in motion relative to a fixed point; and

wherein the determination of the speed comprises detection and consideration of ground speed of the laser-based speed-determination system.

19. The laser-based speed-determination system of claim 18, the system further comprising:

a display device in communication with the processing device; and

wherein the processor is operable to execute instructions to display an annotated field of view on the display device, the annotated field of view comprising the field of view and the determined speed of the target.

20. The laser-based speed-determination system of claim 18, wherein the processor is operable to:

determine, via a digital scan of the field of view, a location of a plurality of targets;

cause, via the laser-aiming device, a laser to be directed from the laser device to the determined location for each of the plurality of targets; and

determine a speed for each of the plurality of targets, the speed being determined via light reflected from the plurality of targets to the laser device.