Method and device for measuring dimensions by X-rays, on empty glass containers running in a line
AssigneeTiama
InventorsLaurent Cosneau, Olivier Colle
Life of this patent
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Abstract
The invention concerns a method for measuring the dimensions of empty glass containers (2) consisting in: selecting at least one region to be inspected of the container, transporting the containers, positioning, on either side of the region to be inspected, at least one focus of an X-ray generator tube and image sensors, acquiring, using image sensors, for each container during its displacement, at least three radiographic images of the inspected region, analyzing the at least three radiographic images so as to determine the three-dimensional coordinates of a set of points to deduce at least one inner diameter of the neck and/or one thickness of the body.
Claims39
A method for measuring dimensions of at least one region to be inspected of empty glass containers of a series (2) each having a wall forming a neck and a body and delimited by an inner surface and an outer surface, the method comprising:
- selecting at least one region to be inspected comprising at least part of the neck and/or part of the container body;
- transporting the containers placed on their bottom in a conveying plane (Pc) along a flat trajectory with a direction materialized by a displacement vector (T), these containers generating a conveying volume (Vt) during their displacement;
- positioning, on either side of the region to be inspected, at least one focus (Fj) of an X-ray generator tube and X-ray sensitive image sensors (Cji) and each exposed to X-rays obtained from an associated focus (Fj), these X-rays having passed through at least the region to be inspected producing on each image sensor a radiographic projection in the projection direction (Dji);
- acquiring using Image sensors (Cji) for each container during its displacement, at least three radiographic images of the inspected region, obtained from at least three radiographic projections of the region to be inspected, the projection directions of which are different;
- constructing, using a computer system, a digital geometric model of the region to be inspected for each container, from at least three radiographic Images, said geometric model containing the three-dimensional coordinates of a set of points, calculated from the at least three radiographic images, this set of points belonging to the inner and/or outer surface of the wall of the container, with at least two points located in a plane not orthogonal to a projection direction (Dji),
- deducing at least one inner diameter of the neck measured on the model in a plane not orthogonal to a projection direction (Dji), and/or at least one thickness of the wall of the body measured on the model in a plane not orthogonal to a projection direction (Dji).
A facility for automatically measuring linear dimensions of at least one region to be inspected of empty glass containers (2) each having a wall forming a neck and a body and delimited by an inner surface and an outer surface, the facility comprising:
- a device (11) for transporting the containers in a direction materialized by a displacement vector (T), along a substantially rectilinear trajectory in a conveying plane (Pc), the containers traversing a conveying volume (Vt) extended in the direction (T);
- at least one focus (Fj) of an X-ray generator tube (12) located outside the traversed volume (Vt), and creating a divergent X-ray beam directed to pass through at least one region to be inspected comprising at least part of the neck and/or part of the container body;
- at least three image sensors (Cji), located outside the conveying volume (Vt), so as to receive X-rays obtained from an associated focus (Fj), the focus or foci (Fj) and the image sensors (Cji) being arranged so that each image sensor receives the radiographic projection of the region to be inspected by the rays obtained from the focus (Fj) when the container passes through these rays, the projection directions of these radiographic projections being different from each other;
- an acquisition system connected to the image sensors (Cji), so as to acquire for each container during its displacement, at least three radiographic Images of the region to be Inspected, obtained from at least three radiographic projections of the region to be inspected, with different projection directions;
- and a computer system analyzing the at least three radiographic images, obtained from at least the three different radiographic projections, so as to build for each container, a digital geometric model of the region to be Inspected, said digital geometric model containing the three-dimensional coordinates of a set of points, calculated from at least three radiographic Images, this set of points belonging to the inner and/or outer surface of the wall of the container, with at least two points located in a plane not orthogonal to a projection direction (Dji), each digital geometric model allowing to deduce at least one inner diameter of the neck measured on the model in a plane not orthogonal to a projection direction (Dji), and/or at least one thickness of the wall of the body measured on the model in a plane not orthogonal to a projection direction (Dji).
Dependencies are inferred from the claim text.