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

• US 20040144934A1
• Filed: 12/18/2003
• Published: 07/29/2004
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: Sick AG (Sick)
• Original Assignee: Sick AG (Sick)
• Inventors: Wehrle, Klemens, Kaltenbach, Thomas, Nubling, Achim, Uhl, Hubert
• Granted Patent: US 7,199,385 B2
• Time in Patent Office: Days
• 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 gravity 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 of gravity 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 the detection of objects (5-7) moved on a segmented conveyor means by means of an optoelectronic sensor (8),characterized in that the geometric center of gravity (S) of the objects (5-7) is respectively determined via the optoelectronic sensor (8), whereupon the objects (5-7) are each associated with that conveyor segment (1-4) in the region of which the respectively determined center of gravity (S) is located.

2. A method in accordance with claim 1, characterized in that such objects (5-7) are also completely detected which lie partly outside a conveyor segment or which are located in the region of two sequential conveyor segments (1-4).

3. A method in accordance with any one of the preceding claims, characterized in that the geometric center of gravity (S) is generally determined on the basis of the detected actual base surface of the object, on the detected projected base surface of the object or on the detected object volume.

4. A method in accordance with any one of the preceding claims, characterized in that a trigger signal is generated for those conveyor segments (1-4) which are loaded with an object (5-7).

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 (1-4) extending in the conveying direction such that the trigger signal characterizes the start and the end of the conveyor segment (1-4).

6. A method in accordance with one of the claims 4 or 5, characterized in that the association of the objects (5-7) with the conveyor segments (1-4) takes place by a comparison of the determined positions of the geometric centers of gravity (S) of the objects (5-7) with the positions determined via the trigger signal of the conveyor segments (1-4) loaded with objects (5-7).

7. A method in accordance with one of the claims 4 to 6, characterized in that an association signal can then be output synchronously with, or with a time delay or a path delay relative to the trigger signal.

8. A method in accordance with any one of the preceding claims, characterized in that an element, in particular a code, a barcode (10) or an address label, located on an object (5-7) is detected and associated with an object (5-7).

9. A method in accordance with claim 8, characterized in that a detected element (10) is associated with that object (5-7) whose geometric center of gravity (S) or whose contour extending parallel to the conveyor plane is closest to the detected element (10).

13. A method in accordance with any one of the preceding claims, characterized in that the objects (5-7) are detected continuously by the optoelectronic sensor (8) over their total length extending in the conveying direction and/or over their total width extending transversely to the conveying direction.

14. A method in accordance with any one of the preceding claims, characterized in that objects (5-7) 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.

15. A method in accordance with one of the claims 1 to 9 and one of the claims 10 to 14.

17. An apparatus in accordance with claim 16 with a data processing unit (9) for the carrying out of a method in accordance with one of claims 1 to 9 or 13 to 15.

10. A method for the determination of the dimensions of objects (5-7) moved on a conveyor means (1-4) by means of an optoelectronic sensor (8) which detects the dimensions of the objects (5-7) and supplies corresponding, object-related values, characterized in that the optoelectronic sensor (8) additionally also detects the dimensions of the conveyor means (1-4) and supplies corresponding, conveyor means-related values, with conveyor means tolerances and/or hollow spaces (12) possibly present between the object (5-7) and the conveyor means (1-4) being compensated 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 (1-4, 11) and/or of the objects (5-7) are detected in all three dimensions.

12. A method in accordance with claim 10 or claim 11, characterized in that the desired dimensions of the conveyor means (1-4, 11) are stored and compared with the detected actual dimensions of the conveyor means (1-4, 11), with the result of this comparison being used as the correction value for the compensation.

19. An apparatus in accordance with claim 18 with a data processing unit (9) for the carrying out of a method in accordance with one of claims 10 to 15.

16. An apparatus for the detection of objects (5-7) moved on a segmented conveyor means by means of an optoelectronic sensor (8), characterized in that the optoelectronic sensor (8) is coupled to an evaluation unit (9) for the determination of the geometric centers of gravity (S) of the objects (5-7), with an association unit being provided for the association of the objects (5-7) with that conveyor segment (1-4) in the region of which the respectively determined center of gravity (S) is located.

20. An apparatus in accordance with one of claims 16 to 19, characterized in that the optoelectronic sensor (8) is designed as a light barrier, as a scanner or as a camera, with it being made in particular for distance measurement.

21. An apparatus in accordance with claim 20, characterized in that the optoelectronic sensor (8) is formed as a laser scanner with a scanning direction extending transversely or obliquely to the conveying direction.

22. An apparatus in accordance with one of claims 16 to 21, characterized in that the optoelectronic sensor (8), or an evaluation unit (9) coupled to it is designed for code recognition and/or for image processing.

23. An apparatus in accordance with one of claims 16 to 22, 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.

18. An apparatus for the determination of the dimensions of objects (5-7) moved on a conveyor means with an optoelectronic sensor (8) for the detection of the dimensions of the objects (5-7) and for the provision of corresponding object-related values, characterized in that the optoelectronic sensor (8) is designed for the additional detection of the dimensions of the conveyor means (1-4, 11) and for the provision of corresponding conveyor means-related values, with a compensation unit (9) being provided for the compensation of conveyor means tolerances and/or of hollow spaces (12) possibly present between the object (5-7) and the conveyor means (1-4, 11).