Perspective tracking system

• US 20070166669A1
• Filed: 12/19/2006
• Published: 07/19/2007
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: Raydon Corporation (By Light Professional IT Services, LLC)
• Original Assignee: Raydon Corporation (By Light Professional IT Services, LLC)
• Inventors: Page, David
• Granted Patent: US 9,052,161 B2
• Time in Patent Office: Days
• US Class Current: 434/21
• 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. With the advent of high resolution image sensors the ability to sense position and orientation using image capture devices is possible. The 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 area of interest markers which identify the region and its physical constraints.

Claims

1. A perspective tracking system comprising:

a perspective tracking device;

at least one area of interest marker;

at least one area of interest defined by said area of interest marker;

wherein said perspective tracking device is adapted to capture one or more frames of said at least one area of interest;

wherein the perspective tracking system analyzes said frames to compute one or more of orientation, perspective, and motion characteristics of said at least one are of interest marker.

2. The system of claim 1 wherein said at least one area of interest marker comprises a light emitter.

3. The system of claim 2 wherein said light emitter is adapted 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 at least one area of interest marker.

6. The system of claim 5 wherein said perspective tracking system is adapted to identify said n-sided polygon by configuration fingerprint.

7. The system of claim 1 wherein said one or more of orientation, perspective, and motion characteristics comprise one or more of:

current coordinates;

predicted future coordinates;

direction;

speed;

acceleration;

point of gaze; and

point of aim.

8. The system of claim 1 further comprising motion sensing equipment.

9. The system of claim 8 wherein said motion sensing equipment comprises one or more of:

an accelerometer;

a gyroscope; and

a magnetometers.

10. The system of claim 1 wherein said perspective tracking system and said at least one area of interest marker are adapted to communicate wirelessly.

11. A perspective tracking method comprising the steps of:

(a) capturing a first frame wherein said frame includes the location of said at least one area of interest marker;

(b) capturing a second frame wherein said second frame includes the location of said at least one area of interest marker;

(c) determining a path based on the locations of said at least one area of interest marker in said first frame and said second frame;

(d) extrapolating a future location of said at least one area of interest marker;

(e) capturing a third frame wherein said subsequent frame includes the location of said at least one area of interest marker;

(f) comparing the location of said at least one area of interest marker in said third frame with said extrapolated future location;

12. The method of claim 11, wherein the frame capturing in steps (b) and (c) comprises:

(i) measuring the light intensity of said at least one area of interest marker over a detection threshold.

(ii) calculating the centroid of the area of interest marker

13. The method of claim 12 wherein step (i) further comprises:

(1) applying correction equations to the light intensity measurements.

14. The method of claim 13 wherein said correction equations yield one or more of:

temperature-based offsets; and

optical error correction.

15. A computer program product comprising a usable medium having control logic stored therein for causing a computer to track the movement and perspective of at least one area of interest marker, the control logic comprising:

first computer readable program code means for capturing a first frame wherein said frame includes the location of said at least one area of interest marker;

second computer readable program code means for capturing a second frame wherein said second frame includes the location of said at least one area of interest marker;

third computer readable program code means for determining a path based on the locations of said at least one area of interest marker in said first frame and said second frame;

fourth computer readable program code means for extrapolating a future location of said at least area of interest marker;

fifth computer readable program code means for capturing a third frame wherein said subsequent frame includes the location of said at least one area of interest marker; and

sixth computer readable program code means for comparing the location of said at least one area of interest marker in said third frame with said extrapolated future location.

16. The computer program product of claim 15, wherein the frame capturing comprises:

(i) measuring the light intensity of said at least one area of interest marker over a detection threshold.

(ii) calculating the centroid of the area of interest marker

17. The computer program product of claim 16, wherein step (i) further comprises:

(1) applying correction equations to the light intensity measurements.

18. The computer program product of claim 17, wherein said correction equations yield one or more of:

temperature-based offsets; and

optical error correction.