Device and method for non-contact detection of structural and/or surface faults in large surface bodies

• US 20010050772A1
• Filed: 04/13/2001
• Published: 12/13/2001
• Est. Priority Date: 10/13/1998
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Meinlschmidt, Peter, Sembach, Joerg
• Granted Patent: US 6,461,035 B2
• Time in Patent Office: Days
• US Class Current: 356/430
• CPC Class Codes: G01N 25/72 Investigating presence of flaws

Abstract

A device for contactless testing of structural and/or surface defects of large-surface bodies, especially of slab-shaped materials includes a conveying device with an unsupported area; a source of heat arranged above the plane of conveyance and extending transversally to the direction of conveyance and which radiates heat in lines or strips onto the plane of conveyance; a thermographic camera having at least one camera line aligned transversally to the direction of conveyance and arranged above the plane of conveyance and after the source of heat in the direction of conveyance; and a computer connected to the camera that has a monitor and generates a separate heat image pattern from every camera line.

Claims

1. A device for non-contact detection of structural and/or surface faults in large-surface bodies, comprising:

a conveying device having a generally horizontal conveying plane and an unsupported area with respect to the large-surface bodies conveyed thereby;

a heat source located above the conveying plane and disposed over the unsupported area, the heat source extending transversely to a direction of conveyance and for radiating heat toward the conveying plane;

a thermal imaging camera positioned above the conveying plane and directed at the conveying plane, said thermal imaging camera having several camera lines arranged in succession and extending transversely to the direction of conveyance; and

a computer and a monitor for processing information recorded in succession from the camera lines of the thermal imaging camera and constructing heat image models of various depths of the large surface bodies.

2. The non-contact detection device as set forth

claim 1

, wherein the conveying device includes two spaced continuous conveyors to create the unsupported area of the conveying device in the area of the heat source.

3. The non-contact detection device as set forth in

claim 1

, including an adjustment device for changing the distance between the heat source and the thermal imaging camera in the direction of conveyance.

4. The non-contact detection device as set forth in

claim 1

, including an adjustment device for changing the speed of the conveying device.

5. The non-contact detection device as set forth in

claim 1

, including an adjustment device for changing the distance of the heat source from the conveying plane.

6. The non-contact detection device as set forth in

claim 1

, including means for adjustment the power delivered to the heat source.

7. A device for non-contact detection of structural and/or surface faults in large-surface bodies, comprising:

a conveying device having a generally horizontal conveying plane and an unsupported area with respect to the large-surface bodies conveyed thereby, the conveying device including two spaced continuous conveyors to create the unsupported area, and means for changing the speed of the conveying device;

a heat source located above the conveying plane and disposed over the unsupported area, the heat source extending transversely to a direction of conveyance and for radiating heat toward the conveying plane, the heat source including means for changing the distance of the heat source from the conveying plane, and means for adjustment the power delivered to the heat source;

;

a thermal imaging camera positioned above the conveying plane and directed at the conveying plane, said thermal imaging camera having several camera lines arranged in succession and extending transversely to the direction of conveyance;

an adjustment device for changing the distance between the heat source and the thermal imaging camera in the direction of conveyance; and

a computer and a monitor for processing information recorded in succession from the camera lines of the thermal imaging camera and constructing heat image models of various depths of the large surface bodies.

8. A method for non-contact detection of structural and/or surface faults in large-surface bodies, comprising:

conveying the large surface bodies in one direction;

heating the large surface bodies with a heat source spaced therefrom;

after heating, taking thermal images of the large-surface bodies using a thermal imaging camera having several camera lines arranged in succession and transverse to said one direction; and

constructing heat image models of various depth planes of the large surface bodies using a computer that processes information recorded in succession from the camera lines to construct said heat image models.