Perspective tracking system

• US 9,052,161 B2
• Filed: 12/19/2006
• Issued: 06/09/2015
• Est. Priority Date: 12/19/2005
• Status: Expired due to Fees

• Current Assignee: Raydon Corporation (By Light Professional IT Services, LLC)
• Original Assignee: Raydon Corporation (By Light Professional IT Services, LLC)
• Inventors: Page, David
• Primary Examiner(s): Gishnock, Nikolai A
• Application Number:
  US11/641,123
• Publication Number:
  US 20070166669A1
• Time in Patent Office: 3,094 Days
• Field of Search: 434/11, 434/16, 434/19, 434/21, 345/157
• US Class Current: 1/1
• CPC Class Codes: F41A 33/00 Adaptations for training adaptations of barrels for recoil reinforcement F41A21/26; Gun simulators teaching or practice apparatus for gun-aiming or gun-laying F41G3/26 ; shooting games A63F9/02; military simulation G09B9/003
• CPC Class Codes: F41G 3/26 Teaching or practice apparatus for gun-aiming or gun-laying shooting games A63F9/02; light- or radiation-emitting guns F41A33/02; targets therefor F41J; responders, transponders for radar, sonar, lidar G01S13/767, G01S15/74, G01S17/74
• CPC Class Codes: F41G 3/2605 using a view recording device cosighted with the gun F41G3/2616 takes precedence
• CPC Class Codes: F41G 3/2661 in which the light beam is sent from the target to the weapon F41G3/2638 takes precedence
• CPC Class Codes: F41J 5/02 Photo-electric hit-detector systems comprising a light-emitting device for simulating the firing of a gun F41G3/2622; detecting by optical means G01V8/10
• CPC Class Codes: F41J 9/00 Moving targets, i.e. moving when fired at F41J2/00 takes precedence
• CPC Class Codes: F41J 9/08 Airborne targets, e.g. drones, kites, balloons aircraft for towing targets B64D3/02
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G01B 21/042 Calibration or calibration artifacts G01B3/30, G01B9/02072 take precedence
• CPC Class Codes: G01S 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: G06F 16/7328 Query by example, e.g. a complete video frame or video sequence graphical querying G06F16/7335
• CPC Class Codes: G06F 16/7335 Graphical querying, e.g. query-by-region, query-by-sketch, query-by-trajectory, GUIs for designating a person/face/object as a query predicate end-user interface involving hot spots associated with the video H04N21/4725; end-user interface for selecting a Region of Interest H04N21/4728
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
• CPC Class Codes: G09B 19/00 Teaching not covered by other main groups of this subclass teaching or practice apparatus for gun-aiming or gun-laying F41G3/26
• CPC Class Codes: G09B 9/00 Simulators for teaching or training purposes for the use of weapons F41; computing aspects G06; protocols for games, networked simulations or virtual reality H04L67/131
• CPC Class Codes: G09B 9/003 for military purposes and tactics
• CPC Class Codes: G09B 9/006 : for locating or ranging of objects
• CPC Class Codes: G09B 9/04 : for teaching control of land vehicles
• CPC Class Codes: G09B 9/08 : for teaching control of aircraft, e.g. Link trainer
• CPC Class Codes: G09B 9/301 : by computer-processed or -generated image
• CPC Class Codes: G09B 9/307 : by helmet-mounted projector or display G09B9/36 takes precedence; optical parts of head-up displays G02B27/01

Abstract

Resolution of perspective in three dimensions is necessary for intermeshing real players into simulated environments during virtual training exercises. A combination of small sized sensors and image recognition tracking algorithms allows the tracking element to be placed directly on the device whose perspective is desired. This provides a solution to determining perspective as it provides a direct measurement from the center axis of the observer. This invention employs a perspective tracking device to determine a point-of-gaze or a point-of-aim in a three-dimensional space to a high degree of accuracy. Point-of-gaze may be used to determine views for head mounted displays and aim-points for weapons. The invention may operate in an unconstrained space allowing simulation participants to operate in a larger, open environment. Areas of interest in the environment are bounded by emitters which identify the region and its physical constraints.

Claims

1. A perspective tracking system comprising:

a computer-based perspective tracking device; and

an array of emitters configured to define at least one area of interest based on emitted signals from at least two emitters in the array of emitters;

wherein the computer-based perspective tracking device is configured to determine a spatial position, orientation, and size of the area of interest based on the emitted signals from the array of emitters;

wherein the computer-based perspective tracking device is configured to capture a plurality of image frames of said at least one area of interest;

wherein the computer-based perspective tracking system is configured to analyze said plurality of image frames to determine a motion formulae of the computer-based perspective tracking device, and

wherein the computer-based perspective tracking system is configured to measure a light intensity of each of the at least two emitters in the array of emitters over a detection threshold and apply a correction equation to the light intensity measurement that yields temperature-based offsets.

2. The system of claim 1 wherein at least one emitter in the array of emitters comprises a light emitter.

3. The system of claim 2 wherein said at least one emitter in the array of emitters is configured to modulate the light to output an identification of said light emitter.

4. The system of claim 3 wherein said identification comprises one or more of:

an identification sequence;

an error correction; and

a validation sequence.

5. The system of claim 1 wherein said at least one area of interest comprises an n-sided polygon defined by said array of emitters.

6. The system of claim 1 wherein said spatial position, orientation, and size comprise:

point of gaze;

or

point of aim.

7. The system of claim 1, wherein the perspective tracking system is configured to determine the motion formulae in six degrees of freedom.

8. The system of claim 7 wherein said determining by the perspective tracking system comprises the use of one or more of:

an accelerometer;

a gyroscope; and

a magnetometer.

9. The system of claim 1 wherein said computer-based perspective tracking device and at least one emitter of the array of emitters are configured to communicate wirelessly.

10. A perspective tracking method comprising:

capturing, using a computer-based system, a first image frame wherein said first image frame includes a first location of a first emitter and a first location of a second emitter;

determining, using the computer-based system, a first area of interest based on the first location of the first emitter and the first location of the second emitter;

determining, based on the first locations of the first and second emitters, a spatial position, an orientation, and a size of the first area of interest;

capturing, using the computer-based system, a second image frame wherein said second image frame includes a second location of said first emitter and a second location of said second emitter;

determining, using the computer-based system, a second area of interest based on the second location of the first emitter and the second location of the second emitter;

determining, based on the second locations of the first and second emitters, a spatial position, an orientation, and a size of the second area of interest; and

determining a motion characteristic of the first and second emitters,

wherein the capture of each image frame comprises measuring a light intensity of each of the first and second emitters over a detection threshold and applying a correction equation to the light intensity measurement that yields temperature-based offsets.

11. The method of claim 10, wherein the capture of each image frame further comprises

calculating a centroid of the light intensity of each of the first and second emitters.

12. The method of claim 10, wherein:

said first image capturing step further comprises capturing said first image frame wherein said first image frame includes a first location of a third emitter;

said first determining step comprises determining said first area of interest based on the first location of each of the first, second, and third emitters;

said second image capturing step further comprises capturing said second image frame wherein said second image frame includes a second location of said third emitter; and

said second determining step comprises determining said second area of interest based on the second location of each of the first, second and third emitters.

13. A computer program product comprising a non-transitory computer usable medium having control logic stored therein for causing a computer to track a movement and a perspective of an array of emitters, the control logic comprising:

first computer readable program code for causing the computer to capture a first image frame wherein said first image frame includes a first location of a first emitter and a first location of a second emitter;

second computer readable program code for causing the computer to determine a first area of interest based on the first location of the first emitter and the first location of the second emitter;

third computer readable program code for causing the computer to determine, based on the first locations of the first and second emitters, a spatial position, an orientation, and a size of the first area of interest;

fourth computer readable program code for causing the computer to capture a second image frame wherein said second image frame includes a second location of said first emitter and a second location of said second emitter;

fifth computer readable program code for causing the computer to determine a second area of interest based on the second location of the first emitter and the second location of the second emitter;

sixth computer readable program code fir causing the computer to determine, based on the second locations of the first and second emitters, a spatial position, an orientation, and a size of the second area of interest; and

seventh computer readable program code for causing the computer to determine a motion characteristic of the first and second emitters,

wherein each of the first and fourth computer readable program code comprises;

computer readable program code for causing the computer to measure a light intensity of each of the first and second emitters over a detection threshold; and

computer readable program code for causing the computer to apply a correction equation to the light intensity measurement that yields temperature-based offsets.

14. The computer program product of claim 13, wherein each of the first and fourth computer readable program code further comprises:

computer readable program code for causing the computer to calculate a centroid of the light intensity of each of the first and second emitters.

15. The computer program product of claim 13, wherein said correction equation yields an

optical error correction.