| CPC C03B 7/005 (2013.01) | 22 Claims |
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1. A measurement method for measuring kinematic characteristics of a free fall of a glass gob in a glass article molding installation, in an area of free fall of the gob along a gob load path between a glass source and a forming cavity, the gob having a theoretical vertical free fall path along a direction in the free fall area and the gob having a start end and a tail end and a gob length between the start end and the tail end, the measurement method comprising:
acquiring, using four distinct linear cameras each linear camera having a linear photoelectric sensor, a lens with an optical center and an optical axis, defining for said linear camera an observed linear field, at least four series of successive digital linear images, each linear image of a given series of linear images being the linear image of the observed linear field of the corresponding linear camera, the four series comprising a first high series acquired by a first high camera, a first low series acquired by a first low camera, a second high series acquired by a second high camera, and a second low series acquired by a second low camera, the four series of linear images corresponding to linear images respectively of a first high linear field, of a first low linear field, of a second high linear field and of a second low linear field such that:
the first high linear field and the first low linear field each extend along a respective plane defined by the corresponding optical axis and a horizontal extension direction perpendicular to the corresponding optical axis, the first high linear field and the first low linear field each intercepting the theoretical free fall path, respectively at a first high point of interception and at a first low point of interception, the first high and low points of interception being offset from each other according to the theoretical free fall path by a vertical offset;
the second high linear field and the second low linear field each extend along a respective plane defined by the corresponding optical axis and a horizontal extension direction perpendicular to the corresponding optical axis, the second high linear field and the second low linear field each intercepting the theoretical free fall path, respectively at a second high point of interception and at a second low point of interception, the second high and low points of interception being offset from each other along the direction of the theoretical free fall path;
the linear images of the four series of linear images each comprising an image of the corresponding point of interception, acquired respectively along a first high axis of observation, a first low axis of observation, a second high axis of observation and a second low axis of observation, the axis of observation of each point of interception by the corresponding linear camera being contained in the linear field of the corresponding linear camera, passing through the optical center of the lens of the camera, and through the corresponding point of interception of the theoretical free fall path;
the first and second high axes of observation form together, in projection on a plane perpendicular to the direction of the theoretical free fall path, a high deviation angle of observation different from 0 angle degree and different from 180 angle degrees around the theoretical free fall path;
the first and second low axes of observation form together, in projection on a plane perpendicular to the direction of the theoretical free fall path, a low deviation angle of observation different from 0 angle degree and different from 180 angle degrees around the theoretical free fall path;
a time interval between the acquisition of any two images of the same series and between any two images of two distinct series is determinable;
the measurement method including a computer identification of a high linear image and a low linear image each comprising an image of a same given end of the gob among the start end and the tail end of the gob and a computer deduction of a time interval between the acquisition of the high linear image and the acquisition of the low linear image and, from said identification:
a computer calculation of an instantaneous speed of vertical translation of said given end of the gob upon passage of the given end of said gob at one among the high and low points of interception, from the time interval between the acquisition of the high linear image and the acquisition of the low linear image, and by application of a law of kinematics of free falling bodies;
and computationally, a matching, for intermediate linear images comprising an image of a segment of the gob other than the start and tail ends, of the image of the gob contained in the intermediate linear image with a corresponding segment of the gob, by application of the law of kinematics of the free falling bodies as a function of said instantaneous speed of vertical translation of the given end of said gob upon passage of the given end of the gob at the point of interception corresponding to said instantaneous speed of vertical translation of the given end of said gob, and of time elapsed between the acquisition of said considered intermediate linear image and said passage of said end of the gob at the point of interception corresponding to said instantaneous speed of vertical translation of the given end of said gob;
and the measurement method including a computer determination of at least one among:
for at least two distinct segments of the gob, a set of first and second amounts of horizontal translation of the segment, or a set of first and second average speeds of horizontal translation of the segment, respectively along a first horizontal measurement axis and along a second horizontal measurement axis, distinct from each other, between the high and low points of interception,
a set of first and second amounts of rotation of the gob, or a set of first and second average speeds of rotation of the gob, respectively around a first horizontal axis and around a second horizontal axis, distinct from each other, between the high and low points of interception,
an amount of deformation of the gob, or an average speed of deformation of the gob, between the high and low points of interception, and
a path of at least one or more segments of the gob according to three dimensions of space.
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