TIME OF FLIGHT (TOF) SENSORS AS REPLACEMENT FOR STANDARD PHOTOELECTRIC SENSORS

• US 20120092485A1
• Filed: 10/18/2010
• Published: 04/19/2012
• Est. Priority Date: 10/18/2010
• Status: Active Grant

• Current Assignee: Rockwell Automation Switzerland GmbH (Rockwell Automation, Inc.)
• Original Assignee: Cedes Safety & Automation AG (Rockwell Automation, Inc.), Rockwell Automation Technologies Incorporated (Rockwell Automation, Inc.)
• Inventors: Meinherz, Carl, Brockman, Craig Martin, Fooks, Elik I., Hardegger, Martin, Chen, Wei Jie, Berner, Reto, Galera, Richard, Black, Robert M., Merz, Roger, Nair, Suresh, Eisenbrown, Steven A., Stein, Manfred Norbert
• Granted Patent: US 9,025,019 B2
• Time in Patent Office: Days
• US Class Current: 348/91
• CPC Class Codes: F16P 3/142 using image capturing devices
• 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 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Abstract

Systems and methods are provided for utilizing time of flight sensors in an industrial automation environment. The method includes employing a multi pixel camera associated with a time of flight sensor to detect an object located within a defined or bounded target area, comparing pixels with adjacent pixels associated with an image of the object captured by the multi pixel camera, identifying the object as being a colored, texture, or highly reflective object, and controlling industrial machinery based on the identification of the object entering the target area.

Claims

1. A method for utilizing a time of flight sensor in an industrial automation environment, comprising:

employing a single or multi pixel camera associated with the time of flight sensor to detect an object located within a target area;

comparing a first pixel with adjacent pixels associated with an image of the object obtained by the single or multi pixel camera;

identifying the object as a shiny object based at least in part on the comparison; and

controlling industrial machinery based at least in part on the identification of the object.

2. The method of claim 1, wherein the target area is proximate to the multi pixel camera.

3. The method of claim 1, wherein the identifying further comprises identifying a color, texture, or finish associated with the image captured by the multi pixel camera.

4. The method of claim 1, wherein the comparing further comprises ascertaining whether the object is located inside or outside the target area.

5. The method of claim 1, wherein the comparing further comprises evaluating a grey scale associated with the image of the object.

6. The method of claim 5, wherein the evaluating is made with respect to one image of the object or a sequence of images of the object obtained by the multi pixel camera.

7. The method of claim 6, wherein the sequences of images is obtained over a staggered period of time.

8. The method of claim 1, wherein the identifying further comprises detecting a movement of the object situated outside the target area.

9. The method of claim 1, wherein the identifying further comprises locating an edge associated with the shiny object.

10. The method of claim 9, wherein the locating further comprises recognizing the shiny object without using a rail.

11. The method of claim 1, wherein the comparing further comprises evaluating a difference between the first pixel and the adjacent pixels with reference to persisted reference data.

12. A system that employs a time of flight sensor to control industrial automation machinery in an industrial automation environment, comprising:

a multi pixel camera associated with the time of flight sensor that captures an image of an object that enters or exits a target area monitored by the multi pixel camera; and

an industrial controller that compares a first pixel with one or more adjacent pixels associated with the captured image of the object, and based at least in part on the comparison the industrial controller instructs the industrial automation machinery to perform an action.

13. The system of claim 12, wherein the industrial controller identifies a color, texture, or finish associated with the detected object.

14. The system of claim 13, wherein the finish associated with the detected object is identified as being highly reflective based at least on a gray scale gradation between an edge of the detected object and a background.

15. The system of claim 13, wherein the industrial controller utilizes an amount of returned light included in the captured image to identify the color, texture, or finish associated with the detected object.

16. The system of claim 12, wherein the industrial controller compares the first pixel associated with the captured image of the object with pixels associated with pixels associated with previously captured images of objects entering or leaving the target area.

17. The system of claim 16, wherein the previously captured images of objects entering or leaving the target area are utilized as persisted reference data.

18. The system of claim 12, wherein the industrial controller identifies whether the detected object is moving outside the target area.

19. A system operable in an industrial automation environment, comprising:

a time of flight sensor that directs a beam of visible or infrared light a single pixel wide towards a three dimensional object situated within a target area that contains no background; and

an industrial controller that compares a returned beam of visible or infrared light a single pixel wide reflected from the three dimensional object with previously or subsequently returned beams of light each a single pixel wide reflected from the three dimensional object, identifies the three dimensional object as having a highly reflective surface, and based at least in part on the identification the industrial controller actuates industrial automation machinery to perform an action.

20. A system that utilizes a time of flight sensor to control industrial automation machinery in an industrial automation environment, comprising:

means for employing the time of flight sensor to detect an object located within a target area;

means for comparing a first pixel with adjacent pixels associated with an image of the object obtained by a means for capture associated with the time of flight sensor;

means for identifying the object as a textured or dark colored object based at least in part on the comparison; and

means for controlling industrial machinery based at least in part on the identification of the object.