CAMERA BASED MOTION SENSING SYSTEM

• US 20100201808A1
• Filed: 02/09/2009
• Published: 08/12/2010
• Est. Priority Date: 02/09/2009
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Hsu, Feng-Hsiung
• Application Number:
  US12/367,665
• Publication Number:
  US 20100201808A1
• Time in Patent Office: Days
• US Class Current: 348/135
• CPC Class Codes: A63F 13/213 comprising photodetecting means, e.g. cameras, photodiodes or infrared cells A63F13/219, A63F13/655 take precedence
• CPC Class Codes: A63F 2300/1087 comprising photodetecting means, e.g. a camera
• CPC Class Codes: A63F 2300/8011 Ball
• CPC Class Codes: G06F 3/0325 using a plurality of light emitters or reflectors or a plurality of detectors forming a reference frame from which to derive the orientation of the object, e.g. by triangulation or on the basis of reference deformation in the picked up image
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

Providing camera based motion detection is disclosed herein. A camera may track a reference element array of retroreflectors, which reflect light from a light source located proximate the camera. A known arrangement of the reference element array may be compared to a received arrangement on an image sensor of the camera to determine position information of at least one of the camera or the reference element array. The reference elements may include a style (pattern, shape) that may enable extraction of additional position information when the reference element array is captured by the camera. A user-manipulated device may be configured with the camera and light source, or alternatively, the reference elements, to enable communication with a computing device and display device.

Claims

1. A system for controlling a computing device, the system comprising:

a light emitting device;

a reference element array including at least one retroreflector, the at least one retroreflector configured to reflect light from the light emitting device back toward an area proximate light emitting device;

a camera located in the area proximate the light emitting device, the camera having an image sensor configured to form an array image upon detection of the reflected light from the reference element array, the array image having a detected arrangement that changes shape in accordance with a change in a relative position between the image sensor and the reference element array; and

a position determination module configured to receive the detected arrangement of the array image, and to generate position information based on the detected arrangement of the array image, the position information to express the relative position between the image sensor and the reference element array.

2. The system as recited in claim 1, wherein the camera is a video camera that is integrally formed in a user-manipulated device used for controlling the computing device.

3. The system as recited in claim 1, wherein the reference element array includes at least three retroreflectors.

4. The system as recited in claim 3, wherein the reference element array is located proximate a display that is connected to the computing device, the retroreflectors spaced along a side of the display to substantially span the side of the display, the reference element array positioned such that the retroreflectors are within a line-of-sight of the image sensor.

5. The system as recited in claim 3, wherein the position determination module is configured to generate position information using geometric relations based on a projection of a reference arrangement through a three-dimensional space onto the image sensor to form the array image.

6. The system as recited in claim 3, wherein the position determination module is configured to generate position information capable of expressing a multi-axis position of the image sensor with respect to the reference elements array along three axes (x-axis, y-axis and z-axis) that describe a translational position.

7. The system as recited in claim 6, wherein the position determination module is configured to generate position information capable of expressing a multi-axis position of the image sensor with respect to the reference elements array that further includes a first rotational axis that describes a pitch motion, a second rotational axis that describes a roll motion, and a third rotational axis that describes a yaw motion.

8. The system as recited in claim 1, wherein the light emitting source emits non-visible light that is redirected from the image source via the at least one retroreflector and detectable by the image source.

9. The system as recited in claim 1, wherein the image sensor is located proximate a display and the reference element array is movably located proximate a user, the display in connection with the computing device and configured to output a graphical representation of the position information.

10. The system as recited in claim 1, wherein the position determination module is configured to track the position of the user-manipulated device in real-time.

11. The system as recited in claim 1, wherein the position determination module receives information of the array image from the image sensor via a wireless transmission.

12. The system as recited in claim 1, wherein the at least one retroreflector include a style that is distinct from any other retroreflector, the style being detected by the array image and used by the position determination module to generate the position information based on a known configuration of the at least one retroreflector.

13. The system as recited in claim 1, wherein the computing device comprises a game console.

14. A method of determining relative position information between objects, the method comprising:

transmitting light from a light source directed toward a retroreflector array, the retroreflector array including at least three retroreflectors with a known spatial arrangement;

receiving an image of the retroreflector array by capturing light that is redirected from each of the retroreflectors toward the light source, the image including a perceived arrangement of the retroreflectors that changes as the relative position changes between the retroreflectors and the light source; and

converting the perceived arrangement into position information based on a known spatial arrangement of the retroreflector array, the position information to express the relative position between the retroreflector array and the light source.

15. The method as recited in claim 14, wherein the position information includes multi-axis information along three translational axes (x-axis, y-axis and z-axis) that describe a translational position and three rotation axes (roll, pitch, yaw) that describe a the rotational motion.

16. The method as recited in claim 14, wherein converting the perceived arrangement into position information includes:

detecting a style associated with each retroreflector;

identifying the retroreflector based on the style to create a style arrangement, and

comparing the style arrangement to the known special arrangement of the retroreflector array to determine the relative position between the retroreflector array and the light source.

17. The method as recited in claim 14, wherein at least one of the retroreflector or light source is located proximate a user-manipulated device used to transmit commands to a computing device to manipulate data represented via a graphical display.

18. A positioning system comprising:

a user-manipulated device having a camera and a proximately located light source that is configured to emit light within a visible range of the camera;

an array of retroreflectors that are configured to reflect light from the light source back toward the camera, each retroreflector to form a reference image recorded by the camera when the camera is activated and at least partially facing the retroreflectors, the reference image to form a detected arrangement that varies as the user-manipulated device changes position in relation to a known arrangement of the array; and

a position determination module configured to receive the detected arrangement of the reference image, and generate position information based on the detected arrangement of the reference image, the position information to express the relative position between the user-manipulated device and the retroreflector array.

19. The system as recited in claim 18, further comprising a display configured to output a graphical representation of the position information, and wherein the retroreflectors are integrally formed with the display.

20. The system as recited in claim 18, wherein the retroreflectors have a known unique style, the unique style being detectable in the array image and used by the position determination module to generate the position information based on a known configuration of the retroreflectors.