METHOD FOR AUTOMATICALLY CONTROLLING AND SELECTING THE BODIES OF SLAUGHTERED POULTRY

PROCEDE DE CONTROLE ET DE SELECTION AUTOMATIQUES DE CORPS DE VOLAILLES ABATTUES

English Abstract

The invention describes a method for automatically controlling and selecting
the bodies of slaughtered poultry. The invention aims at providing a very easy
and cost-effective method for automatically controlling and selecting the
bodies of slaughtered poultry. According to the invention, said aim is
achieved in that the body of the slaughtered poultry to be controlled is
selected by conducting color analysis of the light reflected from the visible
surface parts, said light being detected as a diffuse color mixing light
eliminating spatial contours using a measuring technique, wherein the measured
value is used for selection as integrating value for the totality of visible
surface parts.

French Abstract

L'invention concerne un procédé de contrôle et de sélection automatiques de corps de volailles abattues. L'objectif de l'invention est la création d'un procédé très simple et économique permettant le contrôle et la sélection automatique desdits corps de volailles. Selon l'invention, cet objectif est atteint par le fait que les corps de volailles abattues à contrôler sont sélectionnés par analyse des couleurs de la lumière rétrodiffusée par les parties superficielles visibles, lumière qui est détectée, selon des techniques de mesure, en tant que lumière mixte colorée diffuse éliminant le contour spatial, et dont la valeur de mesure est utilisée, pour la sélection, en tant que valeur d'intégration pour l'ensemble des parties superficielles visibles.

Claims

Claims
1. A method for automatically controlling and selecting
slaughtered poultry bodies by means of color analysis of the
light backscattered from the visible surface parts,
characterized in that the diffuse mixed color light which
eliminates the spatial contour is detected using measurement
technology and its measurement value is used for selection
as an integration value over the entirety of the visible
surface parts.
2. The method for automatically controlling and
selecting slaughtered poultry bodies according to claim 1,
characterized in that mixed color light passing through a
predetermined aperture (2) is objectivelessly received by a
color light sensor (3).
3. The method for automatically controlling and
selecting slaughtered poultry bodies according to claim 1,
characterized in that the color image captured by a color
camera (11) via predetermined software apertures (10) is
accumulated into a mixed color light in the color data
memory (12).
9. The method for automatically controlling and
selecting slaughtered poultry bodies according to one of
claims 1 to 3, characterized in that each measurement and
color is preceded by an integral balancing over a multitude
of measurements.
5. The method for automatically controlling and
selecting slaughtered poultry bodies according to one of
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claims 1 to 4, characterized in that a measurement takes
place on a number of significant different body parts.
6. The method for automatically controlling and
selecting slaughtered poultry bodies according to one of
claims 1 to 5, characterized in that the control device is
comprised of two similar devices with a color light sensor
(3) or color camera (11), which are disposed opposite each
other and thus simultaneously control the front and back of
the slaughtered poultry body.
7. The method for automatically controlling and
selecting slaughtered poultry bodies according to one of
claims 1 to 5, characterized in that the control device has
the additional rear disposition of an optical mirror
opposite from the color light sensor so that at the same
time, the backscattered mixed color light can be received
and controlled from two opposite sides of the slaughtered
poultry body.
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Description

CA 02339965 2001-02-07
Method for Automatically Controlling and Selecting the
Bodies of Slaughtered Poultry
The invention describes a method for automatically
controlling the bodies of slaughtered poultry which after
slaughter, are transported past a control device by means of
a conveyor device and are then selected by means of a
triggered optical measurement that is a function of the
control result.
In modern slaughterhouses, large quantities of poultry
are slaughtered automatically. As a result, the assurance of
quality control and the automatic selection and quality
control that are required by this are of considerable
significance. Only thus can it be assured that on the one
hand, no unhealthy, damaged, or otherwise abnormal poultry
reaches the market and on the other hand, the necessary
product qualities for particular marketing paths can be
presorted.
According to the International Patent Classification
(IPC), the processing of slaughtered poultry bodies is
classified in the class A22B 5/00.
The patent DE19619099 has disclosed the contact-free
evaluation of slaughtered poultry bodies by means of image
processing. In this connection, an optical image of the
complete slaughtered poultry body is photographically
evaluated and is adapted to models for parameter
determination. In addition, there is a detection of
defective regions of the poultry body such as differently
colored image regions.
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The disadvantage of this embodiment is the elaborate
and cost-intensive photographic processing in order to
detect the slaughtered poultry body or its body parts. The
contour detection involves unnecessary error risks and
decreases the reliability in the control of slaughtered
poultry bodies.
Patent DE 196 37 234 A1 describes a process for on-line
verification of the colour purity of structured or unstructured
surfaces, The surfaces are captured by a video camera and the
electronic signals received are evaluated by computer.
Simultaneously with the surfaces, color values of one or more
patterned reference tables are captured, with the optical
resolution of the capture devices set sufficiently low that the
structure of the surfaces is not captured. The integral, specified
color values of a surface are determined. Deviations of the
specific, specified surface colours from a nominal/reference value
can be used, for example, to grade the quality of textiles or of
meat as well. The use of reference tables, the determination of
image points of equal brightness for red, for green, and for blue,
demand correspondingly high effort to perform a color comparison.
Simple and cost-effective selection of damaged or abnormal
slaughter poultry is not possible with this process.
The object of the invention is to produce a very simple
and inexpensive method for automatically controlling and
selecting slaughtered poultry bodies.
The object is attained by means of the features
disclosed in claim 1. Preferred modifications ensue from the
dependent claims.
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The essence of the invention lies in the color analysis
of the mixed color light that is backscattered by the
slaughtered poultry body to be controlled and is received by
means of a color light sensor and the subsequent computer-
executed evaluation of the color data for the required
selection. Through the use of a diffuse mixed color light,
all predetermined visible surface regions are detected
simultaneously and can be evaluated by means of a color
analysis. Consequently, the continuing image processing of
an optical picture is eliminated. In this connection, the
invention makes use of the knowledge that in slaughtered
poultry bodies which are essentially alike, the reliable
selection of very abnormal body regions such as breast,
wing, and leg is of primary interest.
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In a first variant, this mixed color light is generated
without an optical image by means of the objectiveless
reception of the diffusely backscattered light through a
predetermined limiting aperture in front of the slaughtered
poultry body. In a second variant, an illustrative image of
the slaughtered poultry body is captured by a color camera
and the computer-based production of the color image in the
computer, which simply selects the predetermined region by
means of software apertures and respectively accumulates
only the individual color components, by means of which the
mixed color light is consequently produced simply by means
of software. It is advantageous to use a narrow band barrier
filter to suppress a monochromatic background.
In principle, it is conceivable to~link suitable
threshold switches to each piece of color data via logical
subassemblies in order to achieve the evaluation. The
computer preferably used for evaluation and selection
control includes only the evaluation routines and in the
second variant, also includes the routines for the
accumulation within the boundaries of the predetermined
region as well as optionally for control purposes, also
includes an intermediate memory region for a color image
region. In the second variant, the accumulation of the
respective color components is executed within the -
preferably rectangular - boundaries of the color image
region directly during the feeding of this image from the
color camera. In principle, therefore, a micro-controller is
sufficient as the computer. In particular, photographic
image processing routines and their continuous performance
parameters are not required.
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Preferably, the color signals (red, green, blue) used
by conventional color light sensors or color cameras which
are close to the spectral sensitivities of the human eye are
used for the color analysis of the mixed color light.
However, it is also conceivable to use other spectral
regions. The individual color signals of the mixed color
light determine the color in the chromatic circle by means
of their relative components and determine the color
saturation and luminosity by means of their absolute
intensity. With the color signals or alternatively with the
color, color saturation, and luminosity, every detectable
state of the mixed light can simply be described
analytically, preferably vectorially in a mufti-dimensional
space. In particular, definite spatial regions can be
defined which correspond to the selection criteria. Such
selection criteria are, for example, missing body parts,
burns, reddenings, missing skin, protruding bones, etc.
The totality of all the spatial regions should
preferably fill the entire space without overlaps. If
parameters of the analyzed mixed color light lie within a
spatial region of these selection criteria, then the
associated selection or identification, screening, partial
processing is activated.
It is also conceivable that for each measurement and
color, a color balancing is executed by means of the
integral average of a multitude of slaughtered poultry
bodies detected - white balancing - and preferably in
alternation, by means of the integral average of only the
background - black balancing -, by virtue of the fact that
this integral average is respectively treated before the
evaluation as the norming quantity - which is used as a
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CA 02339965 2001-02-07
divisor - or as an offset - which is subtracted from the
measurement value ahead of time. As a result, fluctuations
in the light conditions or characteristic values do not have
a significant effect on the evaluation result. The norming
produces a projection of the evaluation space onto an
associated evaluation plane, preferably color and color
saturation.
There is also the possibility, through the use of a
specially adapted aperture, of using a number of color light
sensors which are each associated with a particular body
part or body section of the slaughtered animal (breast, left
leg, right wing). With the use of a color camera, the
selection of the different body parts and body sections to
be controlled can take place by means of a number of
software apertures.
In a favorable manner, the control device could if
necessary also include two similar arrangements of color
light sensors which are disposed opposite from each other
and thus simultaneously control the backscattered mixed
color light from the front and back of the slaughtered
poultry body.
Another possible embodiment of the control device could
include the additional rear disposition of an optical mirror
opposite from the color light sensor so that at the same
time, the backscattered mixed color light can be received
and controlled from two opposing sides of the slaughtered
poultry body.
The invention will be explained in more detail as an
exemplary embodiment in Fig. 1 as variant 1 with optical

CA 02339965 2001-02-07
apertures and in Fig. 2 as variant 2 with software
apertures.
According to Fig. l, the device for automatically
controlling and selecting slaughtered poultry bodies with
optical apertures is comprised of an illumination device 1
that emits white light, an aperture 2 in front of the
slaughtered poultry body, which narrowly encompasses the
visible outline, an objectiveless color light sensor 3,
which in a position-triggered manner, receives the diffuse
mixed color light backscattered by the slaughtered poultry
body and whose color data are transmitted to a computer 5
via a line 4. The computer 5 executes a color analysis 6 of
the backscattered mixed color light based on the color
signals used. After internal evaluation 7 of the color
analysis according to selection criteria 8, a control signal
9 is emitted in accordance with the respective selection
type associated with the slaughtered poultry body in order
to trigger selection devices in the technological process.
According to Fig. 2, a possible variant of the device
for automatically controlling and selecting slaughtered
poultry bodies with software apertures 10 is comprised of an
illumination device 1 that emits white light, a color camera
11 with a color sensor array whose color image is
transmitted to a computer 5 via a line 4. A predetermined
region of the color image is selected by means of a software
aperture 10 when being fed into the computer 5 and the
respective color data are accumulated in a color data memory
12. This can advantageously occur in line-by-line
transmission of the color image if, by means of suitable
counters, a rectangular region is selectively filtered with
regard to lines/columns as a software aperture 10. The
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computer S executes a color analysis 6 of the represented
mixed color light based on the color data memories 12. After
internal evaluation 7 of the color analysis 6 according to
the selection criteria 8, a control signal 9 is emitted in
accordance with the selection type associated with the
respective slaughtered poultry body in order to trigger
selection devices in the technological process.
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Reference Numerals Used
1 illumination device
2 aperture
3 color light sensor
4 line
computer
6 color analysis
7 evaluation
8 selection criteria
9 control signal
software aperture
11 color camera
12 color data memory
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Representative Drawing