US 8,083,066 B2Granted

Method and machine for automatically inspecting and sorting objects according to their thickness

AssigneePellenc Selective Technologies

InventorAntoine Bourely

Life of this patent

Estimating the term…

Loading patent…

Abstract

This invention has as its object an automatic process and machine for inspecting and sorting non-metallic objects. Process characterized in that it consists essentially in temporarily subjecting a surface or outside layer (4) of objects (1) passing in a single-layer stream to the caloric radiation of at least one remote heating means (5), so as to deliver to each of these passing objects (1) a non-altering heat pulse that is identical for all of the objects in terms of heat energy applied per unit of surface area in the conveying plane (2), then to acquire at least one thermal image of each of said objects by means of at least one linear or matrix thermal sensor (6), for example a thermal camera, this after a determined length of time has elapsed following the application of the heat pulse, then to classify or to categorize each passing object (1) based on data contained in its thermal image or images and to deliver a control or actuation signal for each object and, finally, to separate the passing objects (1) based on their class or category and/or the corresponding control or actuation signal that is delivered.

Claims29

Dependent claims

An automatic process for inspecting and sorting non-metallic objects that belong to at least two different categories and pass in an essentially single-layer stream on a conveying plane of a conveyor belt, comprising:

temporarily subjecting a surface layer (4) of said passing objects (1) to the caloric radiation of at least one remote heating means (5), so as to deliver to each of these passing objects (1) a non-altering heat pulse that is identical for all of the passing objects in terms of heat energy applied per unit of surface area in the conveying plane (2);
after a determined length of time has elapsed following the application of the heat pulse, acquiring at least one thermal image of each of said passing objects by means of at least one linear or matrix thermal sensor (6);
processing data contained in the acquired thermal image to determine a thickness of the surface layer (4) affected by the caloric radiation of the passing objects, and classifying each passing object (1) based on the data, and delivering a control or actuation signal for each passing object;
and
separating the passing objects (1) based on at least one of i) a class or category and ii) the delivered control or actuation signal for each passing object,
wherein the constituent material of said surface layer (4) of the passing objects (1) is identical for all of the passing objects, and
wherein for each passing object (1), the determined length of time that elapses between an application of the caloric radiation and the acquisition of the thermal image is sufficient i) for said surface layer (4) to absorb an essentially homogeneous distribution of caloric energy such that a temperature difference after heating said passing objects on the surface is essentially inversely proportional to the thickness of this surface layer (4), and also ii) so that the phenomena of lateral thermal diffusion, cooling by radiation and convection are negligible.

4 more elements

An automatic machine for inspecting and sorting non-metallic objects, said objects belonging to at least two different categories and passing in a direction and in an essentially single-layer stream on a conveying plane of a conveyor belt, comprising:

at least one remote heating means (5) configured to temporarily subject a surface or outside layer (4) of said passing objects (1) to caloric radiation so as to deliver to each of said passing objects a non-altering heat pulse that is identical for all of said passing objects in terms of thermal energy that is applied per unit of surface area in the conveying plane (2);
at least one linear or matrix thermal sensor (6) placed at a predetermined distance (d) downstream from said at least one heating means (5) in the direction of passing, the at least one thermal sensor (6) configured to acquire at least one thermal image of each of said passing objects;
and
at least one processing unit (12) for performing a discrimination or characterization of said passing objects (1), the at least one processing unit (12) configured to determine a thickness of said surface layer (4) based on data contained the at least one acquired thermal image, to classify each of said passing objects (1) based on the determined thickness, and to deliver a control or actuation signal for each passing object, said at least one processing unit (12) being connected to at least one means (13) for separating said passing objects (1) based on i) a category or class, and ii) the delivered control or actuation signal,
wherein the predetermined distance (d) separating a heating zone (7) in which the thermal energy is applied and a zone in which the at least one thermal image is acquired of each of said passing objects is determined based on a length sufficiently long so that a caloric energy absorbed in the surface layer (4) of each passing object (1) has an essentially homogenous distribution in the surface layer, and also sufficiently short so that effects of lateral thermal diffusion, cooling by radiation, and cooling by convection are negligible, and
wherein the constituent material of at least the surface layer (4) of the passing objects (1) is identical for all of the passing objects (1).

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/159,629Filed 28 Dec 2006
Priority: FR 05 1350730 Dec 2005
Published: US 2008/0302707 A111 Dec 2008
Granted: 27 Dec 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B07C 5/34
Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or…:…
G01N 25/72
Investigating or analyzing materials by the use of thermal means: investigating presence of flaws
Y10S 209/939
Classifying, separating, and assorting solids: video scanning
B07C
Postal sorting