Method and an apparatus for the detection of objects moved on a conveyor means by means of an optoelectronic sensor

• US 7,199,385 B2
• Filed: 12/18/2003
• Issued: 04/03/2007
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: Sick AG (Sick)
• Original Assignee: Sick AG (Sick)
• Inventors: Kaltenbach, Thomas, Wehrle, Klemens, Nubling, Achim, Uhl, Hubert
• Primary Examiner(s): Luu; Thanh X
• Assistant Examiner(s): Wyatt; Kevin
• Application Number:
  US10/739,893
• Publication Number:
  US 20040144934A1
• Time in Patent Office: 1,202 Days
• Field of Search: 250/559.19, 250/559.01, 250/591, 250/221, 250/559.24, 250/559.39, 250/223.R, 356/625, 356/626, 356/627, 356/628
• US Class Current: 250/559.19
• CPC Class Codes: G01B 11/04 specially adapted for measuring length or width of objects while moving

Abstract

The invention relates to a method and to an apparatus for the detection of objects moved on a segmented conveyor means by means of an optoelectronic sensor, in which in each case the geometric center of the objects is determined via the optoelectronic sensor, whereupon the objects are each associated with that conveyor segment in the region of which the respectively determined geometric center is located. The invention further relates to a method and to an apparatus for the determination of the dimensions of objects moved on a conveyor means by means of an optoelectronic sensor, in which the dimensions of the objects are detected and corresponding. object-related values are supplied, and in which the optoelectronic sensor additionally also detects the dimensions of the conveyor means and supplies corresponding, conveyor means-related values, with conveyor means tolerances and/or hollow spaces possibly present between the object and the conveyor means being compensated by an offsetting of the object-related values with the conveyor means-related values.

Claims

1. A method for detecting objects moved on a segmented conveyor means using an optoelectronic sensor, comprising:

determining a geometric center (S) of each of the objects via the optoelectronic sensor, and

associating each of the objects with a respective conveyor segment over which the respective geometric center (S) is located, wherein an object that straddles a plurality of conveyor segments is associated with a single segment over which its respective geometric center (S) is located.

2. A method in accordance with claim 1, characterized in that such objects are also completely detected which lie partly outside a conveyor segment or which are located in two sequential conveyor segments.

3. A method in accordance with claim 1, characterized in that the geometric center (S) is generally determined on the basis of a detected actual base surface of the object, on a detected projected base surface of the object or on a detected object volume.

4. A method in accordance with claim 1, characterized in that a trigger signal is generated for those conveyor segments which are loaded with an object.

5. A method in accordance with claim 4, characterized in that the length in time of a trigger signal corresponds to the length of a conveyor segment extending in a conveying direction such that the trigger signal characterizes the start and the end of the conveyor segment.

6. A method in accordance with claim 4, characterized in that the association of the objects with the conveyor segments takes place by a comparison of determined positions of the geometric centers (S) of the objects with the positions determined via the trigger signal of the conveyor segments loaded with objects.

7. A method in accordance with claim 4, characterized in that an association signal can then be output synchronously, or with a time delay or a path delay relative to the trigger signal.

8. A method in accordance with claim 1 characterized in that an element, in particular a code, a barcode or an address label, located on an object is detected and associated with the object.

9. A method in accordance with claim 8, characterized in that a detected element is associated with the object whose geometric center (S) or whose contour extending parallel to the conveyor plane is closest to the detected element.

13. A method in accordance with claim 1 characterized in that the objects are detected continuously by the optoelectronic sensor over their total length extending in a conveying direction and/or over their total width extending transversely to the conveying direction.

15. A method in accordance with claim 1, characterized in that objects lying close to one another or adjacent to one another are distinguished from one another on the basis of their contours, of their contrast and/or of their color.

10. A method for determining dimensions of objects moved on a conveyor means using an optoelectronic sensor, comprising:

detecting dimensions of objects,

supplying corresponding, object-related values based on the dimensions of the object,

detecting dimensions of the conveyor means using the optoelectronic sensor, wherein the conveyor means includes a non-planar surface over which a planar surface of the object lies, and

supplying corresponding, conveyor means-related values based on the dimensions of the conveyor means, wherein conveyor means tolerances and/or hollow spaces possibly present between the object and the conveyor means are compensated for by offsetting of the object-related values with the conveyor means-related values.

11. A method in accordance with claim 10, characterized in that the dimensions of the conveyor means and/or of the objects are detected in all three dimensions.

12. A method in accordance with claim 10, characterized in that desired dimensions of the conveyor means are stored and compared with detected actual dimensions of the conveyor means, with the result of this comparison being used as the correction value for the compensation.

14. A method in accordance with claim 10 characterized in that the objects are detected continuously by the optoelectronic sensor over their total length extending in a conveying direction and/or over their total width extending transversely to the conveying direction.

16. A method in accordance with claim 10, characterized in that objects lying close to one another or adjacent to one another are distinguished from one another on the basis of their contours, of their contrast and/or of their color.

17. A method for detecting objects moved on a segmented conveyor means using an optoelectronic sensor, comprising:

determining the respective geometric centers (S) of each of the objects via the optoelectronic sensor,

associating each object with the conveyor segment over which the respective geometric center (S) is located, wherein an object that straddles a plurality of conveyor segments is associated with a single segment over which its respective geometric center (S) is located;

determining dimensions of the objects moved on the conveyor means using the optoelectronic sensor,

supplying corresponding, object-related values based on the dimensions of the objects,

detecting dimensions of the conveyor means using the optoelectronic sensor, and

supplying corresponding, conveyor means-related values, wherein conveyor means tolerances and/or hollow spaces possibly present between the object and the conveyor means are compensated for by offsetting of the object-related values with the conveyor means-related values.

18. An apparatus for detecting objects moved on a segmented conveyor means, comprising:

an optoelectronic sensor that is coupled to an evaluation unit for determining respective geometric centers (S) of the objects, and for associating the objects with a respective conveyor segment over which the respective geometric center (S) is located, wherein an object that straddles a plurality of conveyor segments is associated with a single segment over which its respective geometric center (S) is located.

19. An apparatus in accordance with claim 18, characterized in that a data processing unit is provided for the detection of the geometric center (S) of the objects is respectively determined via the optoelectronic sensor, whereupon the objects are each associated with the respective conveyor segment which the respectively determined center (S) is located.

20. An apparatus in accordance with claim 18, characterized in that a data processing unit is provided for receiving signals from the optoelectronic sensor, with the objects being detected continuously over their total length extending in a conveying direction and/or over their total width extending transversely to the conveying direction.

23. An apparatus in accordance with claim 18, characterized in that the optoelectronic sensor is designed as a light barrier, as a scanner or as a camera, with it being made in particular for distance measurement.

24. An apparatus in accordance with claim 23, characterized in that the optoelectronic sensor is formed as a laser scanner with a scanning direction extending transversely or obliquely to a conveying direction.

25. An apparatus in accordance with claim 18, characterized in that the optoelectronic sensor, or an evaluation unit coupled to it is designed for code recognition and/or for image processing.

26. An apparatus in accordance with claim 18, characterized in that the conveyor means is made as a conveyor belt, as a shell conveyor, as a trough conveyor or as a cross-belt conveyor.

21. An apparatus for determining dimensions of objects moved on a conveyor means comprising:

an optoelectronic sensor that detects dimensions of objects and that provides corresponding object-related values, wherein the optoelectronic sensor also detects dimensions of the conveyor means and provides corresponding conveyor means-related values, the conveyor means having a non-planar surface over which a planar surface of the object lies, and

a compensation unit that compensates for conveyor means tolerances and/or of hollow spaces possibly present between the object and the conveyor means by offsetting of the object-related values with the conveyor means-related values.

22. An apparatus in accordance with claim 21 characterized in that a data processing unit is provided;

and in that the optoelectronic sensor also detects the dimensions of the conveyor means and supplies corresponding, conveyor means-related values to the data compensation unit, with conveyor means tolerances and/or hollow spaces possibly present between the object and the conveyor means being compensated by offsetting of the object-related values with the conveyor means-related values.