COUPLED RANGE AND INTENSITY IMAGING FOR MOTION ESTIMATION

• US 20130211657A1
• Filed: 02/10/2012
• Published: 08/15/2013
• Est. Priority Date: 02/10/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: ZENG, Shuqing
• Granted Patent: US 9,069,075 B2
• Time in Patent Office: Days
• US Class Current: 701/28
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/894 3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/269 using gradient-based methods
• CPC Class Codes: G08G 1/16 Anti-collision systems road vehicle drive control systems for predicting or avoiding probable or impending collision otherwise than by control of a particular sub-unit B60W30/08
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A method and system may operate a coupled range imager and intensity imager to obtain a sequence of at least two automatically registered images, each automatically registered image including concurrently acquired range data and intensity data with regard to an imaged scene. The registered range and intensity data is analyzed to yield an estimated motion of an element of an imaged object of the imaged scene.

Claims

1. A method comprising:

operating a coupled range imager and intensity imager to obtain a sequence of at least two automatically registered images, each automatically registered image including concurrently acquired range data and intensity data with regard to an imaged scene; and

analyzing the registered range and intensity data to yield an estimated motion of an element of an imaged object of the imaged scene.

2. The method of claim 1 comprising rescaling pixels of the acquired range data to match pixels of the acquired intensity data.

3. The method of claim 1, wherein obtaining each of the automatically registered images comprises combining a pixel of range data with a corresponding pixel of intensity data to form a pixel of the automatically registered image.

4. The method of claim 1, wherein analyzing the registered range and intensity data comprises finding a range flow plane to constrain the estimated motion.

5. The method of claim 1, wherein analyzing the registered range and intensity data comprises applying an optical flow technique.

6. The method of claim 1, wherein analyzing the registered range and intensity data comprises applying an iterative technique.

7. The method of claim 1, wherein operating the coupled range imager and intensity imager comprises generating a common trigger signal to cause data acquisition by the range imager and the intensity imager.

8. The method of claim 1, wherein operating the range imager comprises operating a light emitting device to emit a pulse of light to be detected by the range imager.

9. The method of claim 8, wherein acquiring the range data comprises measuring a time delay between emission of the pulse and detection of the pulse.

10. The method of claim 1 comprising calculating a time to collision with the imaged object.

11. A system comprising:

collection optics to collect light from a scene and focus the collected light;

an intensity imager detector;

a range imager detector;

a beam splitter to divide light that is collected by the collection optics such that part of the collected light is focused on the intensity imager detector, and another part of the collected light is focused on the range imager detector; and

a controller to control the intensity imager detector to acquire an intensity image of the scene and concurrently control the range imager detector to acquire a range image, to combine the acquired intensity and range images into an automatically registered image, and to analyze a sequence of successively acquired automatically registered images to calculate an estimated motion of an element of an imaged object in the scene.

12. The system of claim 11, wherein the intensity imager detector comprises an array of CCD or CMOS detecting elements.

13. The system of claim 11, comprising an emitter for emitting a pulse of light toward the scene.

14. The system of claim 13, wherein the controller is configured to measure a time of flight between emission of the pulse by the emitter to detection of the pulse by a detecting element of the range imager detector when reflected by an element of the object, and to calculate a range to the element based on the measured time of flight.

15. The system of claim 11, wherein the intensity imager detector is controllable to acquire an intensity image and the range imager detector is controllable to acquire a range image by a single trigger.

16. The system of claim 11, wherein the controller is configured to calculate the estimated motion by calculating an optical flow between successively acquired automatically registered images.

17. The system of claim 16, wherein the calculation of the optical flow comprises a calculation of a range flow plane.

18. The system of claim 11, incorporated into a vehicle.

19. The system of claim 18, wherein the controller is configured to estimate a time to collision with the imaged object.

20. The system of claim 18, wherein the vehicle comprises an autonomous driving system for controlling motion of the vehicle in accordance with the calculated motion of the element.