EP2315650B1 - Method and device for determining control data for a device for slicing food products, and for obtaining constant weight slices based on said control data - Google Patents

Description

The invention relates to a method and a device for determining control data that can be used for a device for slicing food products, in particular a high-performance slicer, and a method for slicing food products. The invention further relates to a method for obtaining weight-constant discs or portions of slices from food products sliced by means of a cutting device, in particular a high-performance slicer, in which a plurality of cross-sectional areas of the product is determined for at least one product to be sliced, in particular according to the light-slit method Total weight of the product is determined, calculated using the cross-sectional areas and the total weight control data, and the cutting device, in particular a product feed of the cutting device, at least partially operated using the control data.
The invention also relates to a device for slicing food products, which operates or is operated in particular according to the above method. This device comprises a product feed, which is designed to supply at least one product to be cut to a cutting plane, in which at least one cutting blade, in particular rotating and / or rotating, moves, in particular working according to the light section method, scanning device for determining a plurality of cross-sectional areas of the product, and a control and computing device for calculating control data using the cross-sectional areas and the total weight of the product and for operating the cutting device, in particular the product feeder, at least in part using the control data.

As will be explained in more detail below, such cutting devices, also referred to simply as slicers, are basically known. For example, with planetary rotating and additionally rotating circular blades or with only rotating sickle blades, the speeds of several 100 to several 1,000 revolutions per minute, are separated at a constant cutting frequency of food products slices. In practice, it is important that either the individual slices or portions formed from a plurality of slices have a predetermined weight. Preferably, since the cutting frequency is constant, the weight of the individual discs is influenced by varying the thickness of the discs, and this is done by appropriate control of the product delivery: the farther the product between two consecutive cuts of the blade over the Cutting edge is pushed out, the greater the thickness of the subsequently separated product disc. The slice thickness is just a parameter that determines the weight of the slice in question. The weight of the disk is determined by the disk volume and the average density of the disk, the disk volume being the disk thickness and the outer surface contour of the disk.
From the WO 99/06796 A1 a device is known for slicing a food product, eg a meat product, into individual slices of predetermined weight (page 1, paragraph 2, page 16, lines 1-6).

The aim is to maximize the yield of the product when slicing and to minimize the loss or waste (page 1, lines 12-14).

The respective food product, which has an irregular surface profile, is guided on a conveyor belt for weight determination via a weighing station and for determining its surface profile by a scanning device, wherein in the scanning device at predetermined intervals in each case the peripheral contour is detected transversely to the transport direction. The signals from the scanner are fed to a microprocessor controller which calculates and stores the cross-sectional area and cross-sectional contours at the predetermined intervals (page 12, lines 2-18).

The volume is calculated from the stored values and the density of the food product is determined by dividing the total weight by the volume (page 15, lines 25-32).

Volume, weight, density and the three-dimensional circumferential contour of the food product are stored in a memory of the microprocessor control unit and can then be supplied from the microprocessor to a processing device for the food product. For example, the stored data for each food or meat product may be fed to a slicer so that the meat product can be cut into slices of predetermined weight, which slicer can determine from the stored data the thickness of each slice to deliver slices of predetermined weight received (page 15, line 33 to page 16, line 6).

The scanning device for determining the peripheral contour of the respective product preferably consists of one or more of this Product swiveling ultrasonic scanning heads. Alternatively, the use of laser scanners or other suitable scanners is suggested (page 17, lines 10-13).

Similar devices and methods are also in WO 99/47885 A2 such as DE 198 20 058 A1 described.

From the DE 196 04 254 A1 For example, a method and an apparatus for obtaining weight-constant portions or slices of cut-up food products of irregular shape are known, as well as in the case of WO 99/06796 A1 the yield from slicing should be increased (page 1, lines 24 and 25).

For this purpose, in turn, the outer surface contour of the respective food product is determined prior to slicing, and the mass of a product piece enclosed by this outer surface contour is calculated directly from the outer surface contour. By correspondingly changing the feed during slicing, the slice thickness can be set as a function of the outer contour so that the slice masses or the slice weights of one serving differ less (page 1, lines 40-42, page 1, lines 67 to page 2, line 1).

In order to detect the entire outer surface contour, in this case a plurality of line projection lasers and a plurality of associated recording devices are provided in the form of cameras which are arranged at a defined angle to the laser (page 3, lines 37-41, page 4, lines 56) -61). The respective camera observes the course of the projected laser line and a computer connected to the cameras calculates the cross-sectional area from the signals obtained a potential product slice (page 3, lines 49-54). The scanning device thus operates according to the so-called light section method.

Depending on the size of the respective cross-sectional area, the disk thickness is varied via the control system of the slicing device.

From the EP 1 178 878 B1 that on the WO 00/62983 A1 is an automatic system for processing a product based on the detection of its surface profile with a conveyor belt on which the product is passed in sequence between a scanning device and a product processing device, wherein the scanning device line laser above and below the product for illuminating the surface profile of the product and cameras for imaging the surface profile indicated by the line lasers. Each line laser is adapted to illuminate the surface profile of the product across a plane transverse to the direction of conveyance of the product, and a controller is connected to the cameras for detecting and processing a plurality of visual images taken by the cameras along the length of the product during the process Throughout the product are detected by the scanning device to determine the volume of the product, wherein the control means is arranged to have carried out the processing of these visual images before the product is processed in the product processing means and the product processing means a control system has to vary their machining operations on the product partly based on the volume of the product.

This system differs from the device according to WO 99/06796 A1 in that instead of a scanning arrangement with moving sensors, which are designed for distance measurement, a scanning arrangement used with line projection or line lasers with associated cameras, as they are for the same purpose from the DE 196 04 254 A1 is known.

As far as the actual procedure in the use of the determined contour or profile data is mentioned at all, the known devices together that from the contour or profile data first the total volume of the product and from this - using the also measured total product weight - calculated the average product density becomes.

The object of the invention is to improve the known systems in terms of the use of the contour or profile data, in particular to minimize the computational effort.

The solution of this object is achieved by the features of the independent claims.

The invention is based on the idea to use exclusively the cross-sectional areas of the product and its total weight for the calculation of the control data by a weight table is created from these directly on the product sizes, which can then be used when cutting or creating a slicing plan.

The invention eliminates any volume computation compared to conventional methods. Furthermore, within the scope of the invention, no mathematical determination of the density based on a determined volume takes place.

Thus, the invention consistently avoids the computation of such quantities, which in themselves are not needed at all to achieve the preferred goal of obtaining weight-constant slices or slices of slices. For that purpose, knowledge of the volume of the product to be sliced is neither necessary nor of interest. The same applies to the average density of the product. By avoiding the calculation of such unnecessary intermediate parameters, the invention can be extremely efficient in processing the cross-sectional areas and the total product weight with the preferred goal of obtaining weight-accurate slices or slice portions.

In a preferred embodiment, the determination of the cross-sectional areas of the product according to the light section method. However, this is not mandatory. Alternatively or additionally, methods based on a different measuring principle can also be used to determine the cross-sectional areas of the product, because how the required cross-sectional areas are specifically determined on the product is irrelevant for the subsequent calculations.

According to a further advantageous embodiment, the cross-sectional areas on the basis of which the weight table is created together with the total weight of the product are in each case an average of two directly successive measured cross-sectional areas.

In a further preferred embodiment of the invention, the cross-sectional areas are determined perpendicular to a Produktzuführrichtung, the cross-sectional areas are determined at constant intervals along this Produktzuführrichtung.

In the case of the methods and devices according to the invention, it can be provided that the determination of the total product weight takes place in the course of the cross-sectional area determination. In particular, a scale for determining the total weight of the product may be integrated in a scanning device used to determine the cross-sectional areas. However, this is not mandatory. The total product weight can also be determined at another time and made available in a suitable manner to the method according to the invention or the device according to the invention in such a way that it can be taken into account in the preparation of the weight table.

Further preferred embodiments of the invention are also specified in the dependent claims, the description and the drawing.

Fig. 1

schematisch eine mögliche Ausgestaltung einer erfindungsgemäßen Vorrichtung,

Fig. 2

eine Darstellung zur Erläuterung der Bestimmung von Querschnittsflächen eines aufzuschneidenden Produkts, und

Fig. 3

eine Darstellung zur Erläuterung einer erfindungsgemäßen Gewichtstabelle.

The invention will now be described by way of example with reference to the drawings. Show it:

Fig. 1

schematically a possible embodiment of a device according to the invention,

Fig. 2

a representation for explaining the determination of cross-sectional areas of a product aufzuschneidenden, and

Fig. 3

a representation for explaining a weight table according to the invention.

In Fig. 1 schematically is a possible embodiment of a slicing device according to the invention, hereinafter referred to simply as slicer shown, which can be operated by the method according to the invention.

The slicer comprises a product feeder 13 which is provided here in the form of a holding or gripping device engaging the rear end of the product 11 to be sliced, which is movable in a product feed direction A by means of a drive (not shown) to move the product 11 perpendicular to the product feed direction A. Feed cutting plane S. In this cutting plane S, a cutting blade 15 moves, which - as already mentioned - can be, for example, a planetary revolving and rotating circular blade or a sickle blade which carries out only a self-rotation. The products to be sliced 11 rest on a product support 27, which extends parallel to the product feed A direction. In addition to the product holder 13 further drive means for the products 11 may be provided, which are not shown here.

At a sufficient distance in front of the cutting plane S, a scanning device 17, shown only schematically here, is arranged, which will also be referred to below simply as a scanner. The scanner 17 serves to determine a plurality of cross-sectional areas of a product 11 to be sliced, running prior to the slicing by the scanner 17 in a scanning plane 29, which in this embodiment is fixed with respect to the cutting plane and also perpendicular to the product feed direction A. With dashed lines is in Fig. 1 For illustrative purposes only, an already scanned product is shown, but the slicing has not yet begun.

In the exemplary embodiment shown here, the scanner 17 operates according to the light-section method and is for this purpose with one or more Light sources, for example, so-called line lasers, and one or more cameras 25 are provided.

In Fig. 1 only one is shown above the product 11 arranged scanning unit. The scanner 17 may additionally comprise a scanning unit arranged below the product 11, suitable means being provided for enabling the underside of the product 11 to be scanned, for example a gap 35 provided on the scanning plane 29 between two consecutive, the product supports 27 at least in the Area of the scanning plane 29 forming endless conveyor belts.

In principle, the scanner 17 can have any desired number of scanning units arranged around the product 11 in the scanning plane 29 in order to scan the product 11 "all around" and thus be able to determine the respective cross-sectional areas with high accuracy.

The basically known light-section method is based on the principle of projecting a light line onto the respective surface to be examined-in this case the surface of the products 11 to be sliced-and to detect this light line with a suitable detection device. Due to the known geometrical conditions, the contour of the surface along the light line can be determined by processing images taken with the detection device. If the surface contour in a plane around the entire object has been determined in this way, the cross-sectional area of the object in this plane can be calculated by means of the light-section method, for example. Since light-section methods, in particular from the prior art already mentioned at the beginning, are also known in connection with the slicing of food products, this will not be discussed in detail.

The slicer comprises according to the embodiment of Fig. 1 In addition, a control and computing device 19, which here comprises two units, one of which is arranged in the scanner 17 and the other at a different location, in particular in a provided for operating the Slicers and in particular the product feeder 13 control. These two units can alternatively be combined into a single unit. In the illustrated embodiment, the cross-sectional areas F (x) measured directly on the product 11 are fed to the slicer unit 19, which also receives the total weight Gges of the product 11, which is measured by means of a balance 21. The scale 21 may be a component of the scanner 17, but in principle may also be arranged at another location of the slicer or in front of the slicer.

The measured cross-sectional areas F (x) transmitted to the slicer unit 19 are a set of cross-sectional areas which are measured at constant intervals along the product feed direction A on the product 11. This can be achieved, for example, by moving the product 1 through the scanner 17 at a constant speed and operating the scanner 17 at a constant recording frequency. The constant distance dx between two directly successive measured cross-sectional areas F (x) is for example 5 mm. By varying the product feed rate and / or scan frequency of the scanner 17, this constant distance, also referred to as scan or pitch, may be changed to thereby change the accuracy or resolution at which the product 11 is scanned and for its performance Outside contour or its profile is measured.

In the manner according to the invention, as will be described in more detail below, the control and computation unit 19 calculates the cross-sectional areas of the product 11 and its total weight Gges control data C, thus in this way, when slicing the product 11 in the manner explained above, the slice thickness and thus to vary the weight of the disc in the desired manner, in particular with the aim of separating weight-constant discs or weight-constant slice portions from the product 11.

The calculation of the control data C can be carried out completely or partially in one of the two arithmetic units 19, i. in whole or in part, either in the scanner 17 or entirely or partially on the slicer, i. e.g. in the slicer control. This is at the discretion of the user.

The manner according to the invention of using the cross-sectional areas of the product and the total product weight for determining the control data C, in particular for establishing a weight table, which can then be used for slicing or for creating a slicing plan, will be described below with reference to FIGS Fig. 2 and 3 explained.

Fig. 2 shows a schematic side view of a aufzuschneidenden food product 11, already completely eg by means of a based on Fig. 1 explained scanner 17 was scanned. At constant distances dx along the product feed direction A, n cross-sectional areas F (xi) were determined. Here and below, i = 1 to n always apply.

A front product end 31 and a rear product residue 33, which in Fig. 2 are indicated by a dashed line, are not considered here. The front end of the product 31 represents one in practice not recycled bleed, while the rear product residue 33 is also not recycled and in particular serves to attack a product holder (see. Fig. 1 ).

In a preferred embodiment of the invention, the creation of the weight table does not take place directly with the cross-sectional areas F (xi) measured directly on the product 11, but with mean values Fi, for which in each case the in Fig. 2 given relationship applies. In the following, that piece of the product 11 which lies exactly between two successive measured cross-sectional areas is referred to as a segment. The product 11 thus comprises n segments. The mentioned average values of the measured cross-sectional areas, which are also referred to below as average cross-sectional areas or simply as cross-sectional areas, are therefore in each case within the relevant product segment. The mean cross-sectional areas Fi are for the two first segments of the product 11 in FIG Fig. 2 located. Each average cross-sectional area Fi represents the cross-sectional area which is used in the further calculation for the relevant segment i.

From the mean cross-sectional areas Fi, first of all an area sum Fges is determined, according to the in Fig. 2 1, all n average cross-sectional areas Fi are added up.

From the total product weight Gges, the average cross-sectional areas Fi and the total area Fges, which is also referred to as average area sum, since it is formed by adding up the average cross-sectional areas Fi, a weight table is created according to the invention, to explain them Fig. 3 Reference is made.

The left part of the Fig. 3 FIG. 2 illustrates a weight profile of a product to be sliced, in which the points represent values actually determined by measurement which are just the elements of the mentioned weight table shown in the right part of FIG Fig. 3 is shown.

This weight table represents the successive, segmental addition of the weights Gi of the individual segments i. At the measuring point x4, for example, ie at the end of the fourth segment, the previously swept by the scanner 17, ie by the scanning plane 29 (see FIG. Fig. 1 ) Weight of the product 11 is the sum of the weight G1 of the first segment, the weight G2 of the second segment, the weight G3 of the third segment and the weight G4 of the fourth segment. This sum is referred to here as Gbis4. In general, therefore, the relationship applies: $$\mathrm{Gbis}\left(\mathrm{i}\right)=\mathrm{Gbis}\left(\mathrm{i}-1\right)+\mathrm{Gi},$$

At the end of the product 11, that is to say after the complete scanning of the product 11 and thus at the end of the nth segment, the value Gbisn in the weight table is shown. all weights Gi of the n segments were added. The value Gbisn thus corresponds to the total weight Gges of the product 11.

According to equation (1), the weight table is thus created by successively adding up the segment weights Gi. These segment weights Gi are calculated from the cross-sectional areas Fi, the mean total area Fges and the total product weight Gges according to the following inventive approach: $$\mathrm{Gi}=\mathrm{gges}\cdot \frac{\mathrm{Fi}}{\mathrm{fges}},$$

The approach according to equation (2) is based on the knowledge that the weight Gi of a segment of the product relative to the total weight Gges of the product is the same as the mean cross-sectional area Fi of the relevant segment relative to the mean total sum Fges. This approach according to equation (2) can be derived from the assumption that the density D of the product 11 is constant, and that also the step size dx between two successive measured cross-sectional areas F (x) is a constant.

Taking the density D as constant, the density D can be calculated from both the total weight Gges of the product and its total volume Vges, as well as the weight Gi of any piece of the product having the volume Vi. For example, this arbitrary product piece may be one of the segments i, rather than the product piece lying between two successive measured cross-sectional areas F (x) of the product.

Consequently, the following relationship can be established: $$\frac{\mathrm{gges}}{\mathrm{Vges}}=\frac{\mathrm{Gi}}{\mathrm{vi}},$$

If, as here assumed, the step size dx is constant, then for each segment volume Vi = dx * Fi, and also for the total volume Vges of the product Vges = dx * Fges. By substituting these two equations for the segment volume Vi and the total volume of the product Vges in the above equation (3) and then converting the resulting equation, the above equation (2) results, ie the approach used for the creation of the weight table for the segment weights Gi.

The above statements are only intended to show under what conditions the approach according to equation (2) is correct. In fact, in the invention neither a volume calculation nor a density calculation is carried out since equation (2) includes only area values and the total product weight.

As mentioned above, the weight table created in this way can be used during slicing or as part of creating a slicing schedule.

It should again be pointed out that the weight table only contains discrete weight values for partial sums of the segment weights Gi. These partial sums are - as mentioned - by the points in the left representation of Fig. 3 illustrated. If one connects these points, ie the individual partial sums, in each case by a straight line, then one receives in the left representation of the Fig. 3 shown weight course of the product in question. The searched values for the slice thickness, which must be realized by means of the product feed, respectively, in order to obtain a specific slice weight, are obtained by interpolating between the discrete values of the weight table. This will be explained below, also with reference to the left-hand illustration of Fig. 3 ,

If, for example, during the cutting process, the cutting blade is located at the point xa in the fifth segment, ie between the fourth measured cross-sectional area F (x4) and the fifth measured cross-sectional area F (x5) after separating a product slice and due to an external specification, the next product slices to be separated should have, for example, a weight of 20 g, then the question arises as to how far the product 11 must be advanced next, so that the product slice subsequently separated from the product 11 at the position xb has a weight of 20 g. The sought size, namely the required pane thickness and thus the required, applied by the product supply travel for the product 11, can be derived in a simple manner from the weight profile. In the left illustration of the Fig. 3 this was done purely schematically in a graphic manner. The control and computing unit 19 (see. Fig. 1 ) performs corresponding arithmetic operations on the basis of the values present in the form of the weight table.

Thus, in the above example, the cutting blade stands at the position xa in the product, which corresponds to a cumulative product weight of Ga, and thus the position xb corresponding to a cumulative product weight Gb = Ga + 20 g is sought. The following equation (4) indicates how xb results by interpolating between the locations x4 and x5 of the weight table. Gbis5 - Gbis4 is the weight of the respective segment whose thickness corresponds to the constant increment dx. Further, Gb-Ga denotes the predetermined target weight of the slice to be separated (20 g in this example) whose thickness is xb-xa. This rule of three relationship after xb gives the following equation (4) $$\mathit{xb}=\mathit{xa}+\mathit{dx}\cdot \frac{\mathit{gb}-\mathit{ga}}{\mathit{Gbis}5-\mathit{Gbis}4},$$

According to the invention, therefore, the illustrated weight table is created exclusively from the cross-sectional areas Fi and the total weight Gges of the product, with the in the manner explained above working during slicing or as part of creating a slicing plan. A calculation of unnecessary quantities, such as the product volume or the average product density, is not provided according to the invention.

LIST OF REFERENCE NUMBERS

11

product

13

product feed

15

cutting blade

17

scanning

19

Control and computing device

21

Libra

23

Light source, line laser

25

Detection device, camera

27

product support

29

scan

31

front end of product

33

rear end of product

35

gap

A

product feed

C

control data

F (x)

measured cross-sectional areas

Fi

Cross-sectional areas

fges

total area

gges

Product total weight

dx

distance

Claims (12)

1. A method for determining control data (C) for an apparatus for slicing food products, in particular for a high-performance slicer, in which, for at least one product (11) to be sliced,

   - a plurality of cross-sectional areas Fi of the product (11) are determined, in particular in accordance with the light sectioning process;

   - the total weight Gtot of the product (11) is determined;

   - control data (C) are calculated using the cross-sectional areas Fi and the total weight Gtot; and

   - the cutting apparatus, in particular a product feed (13) of the cutting apparatus, is operated at least in part using the control data (C),

   characterized in that
   a weight table Gto(i) is prepared for calculating the control data (C) only from the cross-sectional areas Fi and from the total weight Gtot in accordance with $$\mathrm{Gto}\left(\mathrm{i}\right)=\mathrm{Gto}\left(\mathrm{i}-1\right)+\mathrm{Gi},$$

   

   wherein $$\mathrm{Gi}=\mathrm{Gtot*Fi}/\mathrm{Ftot\; and\; i}=1\mathrm{to\; n;}$$

   

   and in that an interpolation is carried out between mutually following values of the weight table Gto(i) for calculating the control data (C).
2. A method for acquiring slices or portions of slices of constant weight from food products sliced by means of a cutting apparatus, in particular by means of a high-performance slicer,
   characterized in that
   the cutting apparatus, in particular a product feed (13) of the cutting apparatus, is operated at least in part using the control data (C) determined by the method in accordance with claim 1.
3. A method in accordance with claim 2,
   characterized in that
   a product feed (13) of the cutting apparatus is configured to supply the product (11) along a product feed direction (A) to a cutting plane (S) in which at least one cutting blade (15) moves, in particular in a rotating and/or revolving manner, with the product feed direction (A) extending perpendicular to the cutting plane (S).
4. A method in accordance with claim 2 or claim 3,
   characterized in that
   the cross-sectional areas Fi are determined perpendicular to a product feed direction (A).
5. A method in accordance with any one of the preceding claims,
   characterized in that
   the cross-sectional areas Fi are determined at constant intervals dx along the product feed direction (A).
6. A method in accordance with any one of the preceding claims,
   characterized in that
   the cross-sectional surfaces Fi are each calculated as a mean value of two cross-sectional areas F(x) measured directly following one another.
7. A method in accordance with any one of the preceding claims,
   characterized in that
   the weight table Gto(i) is prepared before the start of the slicing of the product (11); and/or
   in that the control data (C) are calculated during the slicing.
8. A method in accordance with any one of the preceding claims,
   characterized in that
   a slicing plan is prepared before the start of slicing of the product (11) using the weight table Gto(i).
9. An apparatus for determining control data (C) for an apparatus for slicing food products, in particular for a high-performance slicer, in particular for carrying out a method in accordance with any one of the preceding claims, comprising
   a scanning device (17), in particular working in accordance with the light sectioning process, for determining a plurality of cross-sectional areas Fi of the product (11); and
   a control and calculation device (19) for calculating control data (C) using the cross-sectional areas Fi and the total weight Gtot of the product (11) and for operating the cutting apparatus, in particular the product feed (13), at least in part using the control data (C),
   characterized in that
   the control and calculation device (19) is configured to prepare a weight table Gto(i) for calculating the control data (C) only from the cross-sectional areas Fi and from the total weight Gtot in accordance with $$\mathrm{Gto}\left(\mathrm{i}\right)=\mathrm{Gto}\left(\mathrm{i}-1\right)+\mathrm{Gi},$$

   

   wherein $$\mathrm{Gi}=\mathrm{Gtot*Fi}/\mathrm{Ftot\; and\; i}=1\mathrm{to\; n}$$

   

   and to carry out an interpolation between mutually following values of the weight table Gto(i) for calculating the control data (C).
10. An apparatus in accordance with claim 9,
    characterized in that
    the apparatus comprises scales (21) for measuring the total weight Gtot of the product (11).
11. An apparatus for slicing food products, in particular a high-performance slicer, comprising a product feed which is configured to supply at least one product (11) to be sliced to a cutting plane (S) in which at least one cutting blade (15) moves, in particular in a rotating and/or revolving manner,
    characterized by
    an apparatus for determining control data in accordance with one of the claims 9 or 10.
12. An apparatus in accordance with claim 11,
    characterized in that
    the apparatus is operated in accordance with a method in accordance with any one of the claims 1 to 8.

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