Systems and methods for detecting the movement of an object

• US 8,737,685 B2
• Filed: 04/25/2011
• Issued: 05/27/2014
• Est. Priority Date: 04/25/2011
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Becker, Karl, Lyn-Sue, Nicholas, Rodriguez, Manuel I., White, John
• Primary Examiner(s): ANSARI, TAHMINA N
• Application Number:
  US13/093,548
• Publication Number:
  US 20120269387A1
• Time in Patent Office: 1,128 Days
• Field of Search: None
• US Class Current: 382/103
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30204 Marker
• CPC Class Codes: G06T 2207/30248 Vehicle exterior or interior
• CPC Class Codes: G06T 7/254 involving subtraction of images

Abstract

Systems and methods are provided for detecting a movement of an object marked with a marker. The system includes a sensor configured to capture a first image of the marker and to capture a second image of the marker after the first image, each of the first and second images having pixels each having a visual intensity. A controller is configured to compare the first image and the second image by comparing the visual intensity of each of the pixels of the first image and the second image, determine an area of overlap between the first image and the second image based on the comparison, calculate a change in position of the marker in the second image relative to the marker in the first image based on the area of overlap, and detect the movement of the object based on the change in position of the marker.

Claims

1. A system for detecting a movement of an object marked with a marker, comprising:

a sensor configured to capture a first image of the marker and to capture a second image of the marker after the first image, each of the first and second images comprising pixels each having a visual intensity; and

a controller coupled to the sensor and configured to;

compare the first image and the second image by comparing the visual intensity of each of the pixels of the first image with the visual intensity of each of the pixels of the second image,

determine an area of overlap between the first image and the second image based on the comparison,

calculate a change in position of the marker in the second image relative to the marker in the first image based on the area of overlap, and

detect the movement of the object based on the change in position of the marker,

wherein the marker is a circle and the controller is configured to determine the area of overlap as an intersection of a first arc associated with the marker in the first image and a second arc associated with the marker in the second image,

wherein the controller is configured to compare the first image and the second image by summing values associated with the visual intensity of the pixels of the first image with values associated with the visual intensity of the pixels of the second image to generate composite pixel values.

2. The system of claim 1, wherein the controller is configured to determine the visual intensity of the pixels of the first image and the visual intensity of the pixels of the second image in grayscale.

3. The system of claim 2, wherein the controller is configured to determine the visual intensity as a 1 or a 0.

4. The system of claim 2, further comprising memory coupled to the controller and configured to store the visual intensity of the pixels of the first image with a resolution of 1-bit per pixel.

5. The system of claim 1, wherein the intersection is defined by a first intersection point, a second intersection point, and a chord with a length extending between the first intersection point and the second intersection point, and wherein the controller is configured to determine the change in the position of the marker between the first image and the second image based on the length of the chord.

6. The system of claim 5, wherein the controller is configured to determine a direction of the change in position based on a perpendicular vector extending from the chord.

8. The system of claim 1, wherein the system is a navigation system of a vehicle, and wherein the controller is configured to calculate a kinematic state of the vehicle based on the movement of the object.

9. The system of claim 1, wherein the controller is configured to determine the area of overlap by identifying relatively large composite pixel values.

16. The system of claim 1, wherein the controller is configured to calculate the change in position such that,

as the area of overlap increases, an extent of the change in position decreases, and

as the area over overlap decreases, the extent of the change in position increases.

7. A system for detecting a movement of an object marked with a marker, comprising:

a sensor configured to capture a first image of the marker and to capture a second image of the marker after the first image, each of the first and second images comprising pixels each having a visual intensity; and

a controller coupled to the sensor and configured to;

compare the first image and the second image by comparing the visual intensity of each of the pixels of the first image with the visual intensity of each of the pixels of the second image,

determine an area of overlap between the first image and the second image based on the comparison,

calculate a change in position of the marker in the second image relative to the marker in the first image based on the area of overlap, and

detect the movement of the object based on the change in position of the marker,

wherein the marker is a circle and the controller is configured to determine the area of overlap as an intersection of a first arc associated with the marker in the first image and a second arc associated with the marker in the second image,

wherein the sensor defines a field of view, and wherein the field of view is selected based on an anticipated change of position of the marker in the second image relative to the first image.

10. A method for detecting a movement of an object marked with a marker, the method comprising the steps of:

capturing a first image of the marker;

capturing a second image of the marker, the first and second images comprising pixels, each with a respective visual intensity;

comparing the first image and the second image by comparing the visual intensity of each of the pixels of the first image with the visual intensity of each of the pixels of the second image;

determining an area of overlap between the first image and the second image based on the comparison;

calculating a change in position of the marker in the second image relative to the marker in the first image based on the area of overlap; and

detecting the movement of the object based on the change in position of the marker,

wherein the step of capturing the second image includes selecting a field of view based on an anticipated change of position of the marker in the second image relative to the first image,

wherein the marker is a circle, and wherein the step of determining the area of overlap includes identifying an intersection of a first arc associated with the marker in the first image and a second arc associated with the marker in the second image.

11. The method of claim 10, wherein the steps of capturing the first image and capturing the second image include capturing the first image and the second image in grayscale.

12. The method of claim 10, wherein the intersection is defined by a first intersection point, a second intersection point, and a chord with a length extending between the first intersection point and the second intersection point, and wherein the calculating step includes calculating the change in position based on the length of the chord.

13. The method of claim 12, wherein the calculating step includes calculating a direction of the change in position based on a perpendicular vector extending from the chord.

14. The method of claim 10, wherein the comparing step includes summing values associated with the visual intensity of the pixels of the first image with values associated with the visual intensity of the pixels of the second image to generate composite pixel values.

15. The method of claim 14, wherein the determining step includes identifying relatively large composite pixel values as the area of overlap.

17. The method of claim 10, wherein calculating step includes calculating the change in position such that an extent of the change in position is negatively correlated to the area of overlap.