Apparatus and method for cutting middle pieces of a half carcass

Abstract

The present invention relates to a method and apparatus for longitudinal cutting of a middle piece of a half carcass into a dorsal part and ventral part. In particular the present invention relates to a method and apparatus for the longitudinal cutting of middle pieces using a cutting path as close to the fillet inside the middle piece as possible without cutting in the fillet.

Description

[0001] Apparatus and method for cutting middle pieces of a half carcass

[0002] Technical field of the invention

[0003] The present invention relates to a method and apparatus for longitudinal cutting of middle piece of a half carcass into a dorsal part and ventral part. In particular the present invention relates to a method and apparatus for the longitudinal cutting of middle pieces using one or more optical recording device(s) for providing a digital representation of the middle piece and using a software agent for determination from said digital representation a cutting path of the middle piece. The cutting path is determined by the software agent based on a determined position, in the digital representation, of at least one rib and a position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece. In particular, the software agent determines a position on at least one rib at a distance from a rib reference point and determines the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece of the half carcass. Further, the software agent determines the cutting path based on an off-set to the position on the at least one rib and an off-set to the position on the surface of the middle piece being offset to the fat layer adjacent the fillet inside the middle piece and cuts the middle piece in the determined cutting path by using a digitally controlled cutting tool. Hereby, the cutting path is as close to the fillet inside the middle piece as possible without cutting in the fillet.

[0004] Background of the invention

[0005] In slaughterhouses, carcasses are typically split into two half carcasses through the spinal column along a median sagittal plane. After splitting of a carcass, such as a carcass from a mammal, each half carcass is cut along transverse planes into several pieces, such as fore-ends (known as shoulder or butt in pork and lamb, and as the chuck beef in beef), middle pieces (two or three separate sections in beef) and the back-end (known as ham in pork, round in beef and leg in lamb). These parts undergo separate processing. One process is dividing of the middle pieces to separate the meat around the ventral body cavity into the dorsal part and the ventral part by a longitudinal cut placed around the coronal plane to separate different muscle groups and bones for further processing. This can for example be carried out using the method and apparatus disclosed in EP 1 228 693 Al or EP 0 985 348 A2. In EP 1 228 693 Al and EP 0 985 348 A2, the middle pieces are placed on a conveyor and gripped by gripping means before cut by a rotating circular knife in a longitudinal direction splitting the middle into a ventral part and a dorsal part.

[0006] Further, WO 98 / 53 695 discloses a loin puller apparatus for separating the loin portion of meat from a middle piece. WO 98 / 53 695 discloses that the apparatus cuts through the ribs of a carcass middle. WO 2002 / 13 619 discloses a loin pulling apparatus for separating loin and back fat from a carcass middle piece with the use of a dual blade loin knife assembly.

[0007] However, when splitting a middle pieces into dorsal and ventral part close to the muscle group boundaries, there is a high risk of cutting into the fillet, since the fillet is not visible anywhere on the surface of the meat, but is hidden below the surface of the meat. Cutting into the fillet decreases its value considerably.

[0008] Hence, an improved apparatus and method of cutting middle pieces into the dorsal part and the ventral part would be advantageous, and in particular a more efficient and / or reliable cutting of middle pieces into dorsal part and ventral part with low risk of cutting into the fillet would be advantageous. In addition, an apparatus and method of cutting middle pieces into the dorsal part and ventral part with the use of an apparatus comprising fewer mechanical parts would be advantageous, in particular avoiding complicated gripping means for holding and fixation of the middle piece would be advantageous.

[0009] In addition, when splitting the middle pieces into the dorsal part and ventral part, the ideal cutting line / curve is dependent of characteristics of each individual carcass. Further, there is typically demands for different types of cuts, for example a desire for different length of the ribs. Hence, there is also a need for an improved apparatus and method of cutting middle pieces that can vary dependent on the characteristics of the individual middle piece and dependent on the customer demands.

[0010] Summary of the invention

[0011] Thus, an object of the present invention relates to providing an improved method and apparatus for longitudinal cutting of middle pieces of a half carcass into a dorsal part and ventral part with low risk of cutting into the fillet, but where the cut is being as close to the fillets as possible.

[0012] Further, it is an object of the present invention to provide an improved method and apparatus for longitudinal cutting of middle pieces where it is easy to vary the cutting line dependent of the characteristics of the individual carcass and dependent on specific customer demands. Several cutting specifications and associated commercial cuts exist from different customers, and are defined by for example the total size of cutting parts (such as a certain width) and the anatomical features, such as the length of ribs, and / or whether an individual muscle group should be included or not. It is advantageous to be able to place the longitudinal cut of the middle piece to separate exactly the muscle groups wanted on each side of the cut, since the selling price for the different parts can vary considerably. Thus, increasing the accuracy of the cut has a commercial value.

[0013] In addition, the anatomy of the fillet inside the meat is quite variable, and even cutting in a size-dependent distance from an anatomical feature in the spine gives rise to quite large variation of the cut (standard deviation of about 8-10 mm). This means that some pieces will have fillet damage while superficially comparable pieces still have large quantities of meat placed undesirably when cutting with the method of the prior art. Skilled operators can cut better than this but will get tired quickly. Unskilled operators will do much worse, and training to do this job is above average difficulty. The method presented here can lower the standard deviation by a factor of 2 to 3 times over the prior art. In addition, it is an object of the present invention to provide an improved method and apparatus for longitudinal cutting of middle pieces where complicated gripping means as known from EP 1 228 693 Al or EP 0 985 348 A2 are avoided.

[0014] In particular, it is an object of the present invention to provide a method and apparatus that solves the above mentioned problems of the prior art.

[0015] Thus, one aspect of the invention relates to a method for longitudinal cutting of middle piece of a half carcass into a dorsal part and a ventral part, said method comprising the following steps: i) conveying a middle piece of a half carcass on a conveyor, wherein the middle piece of the half carcass is placed on the conveyor with the skin side downwards; ii) providing a software agent being trained to locate in a digital representation of the middle piece a position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece; iii) determining a digital representation of a cutting path for longitudinal cutting of the middle of the half carcass by: a) providing by use of one or more optical recording device(s) a digital representation of the middle piece of the half carcass placed on the conveyor; b) determining in said digital representation and by use of said software agent:

[0016] • at least one rib and rib reference point of the middle piece of the half carcass;

[0017] • a position on the at least one rib from the rib reference point as a user provided length from the rib reference point;

[0018] • the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece;

[0019] • a digital representation of a longitudinally cutting path between an off-set to the determined position on the at least one rib and an offset to the located position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece; iii) digitally controlling a computer controlled cutting tool to cut the middle piece of the half carcass longitudinally along the determined cutting path by said cutting tool receiving said digital representation of a longitudinal cutting path.

[0020] Another aspect of the present invention relates to an apparatus for longitudinal cutting of middle pieces of a half carcass into a ventral part and a dorsal part, said apparatus comprising: i) a conveyor for conveying a middle piece of a half carcass along a conveying path with its skin side facing downwards; ii) one or more optical recording device(s) configured for providing a digital representation of the middle piece of the half carcass while being placed on the conveyor; iii) a software agent being trained to determine from said digital representation of a middle piece: a) at least one rib and rib reference point of the middle piece; b) a position on the at least one rib a length from the rib reference point; c) a position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece; d) a cutting path going through an off-set to the determined position on the at least one rib and an off-set to the determined position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece; iv) a computer controlled cutting tool for cutting the middle piece of half carcass in the longitudinal direction along the determined cutting path; v) a controller for digitally controlling the cutting tool to cut the middle piece of the half carcass longitudinally along the determined cutting path.

[0021] Brief description of the figures

[0022] Figure 1 shows a section view of a middle piece of a half carcass. Figure 1 shows the belly and loin side of the middle piece. Further, figure 1 shows the fillet and the fat layer enclosing the fillet, and in particular the fat layer located adjacent the fillet close to the ventral side of the middle piece. Figure 1 also discloses the hip point of the middle piece with reference sign "Y". The hip point is the point inside the middle piece where the fillet is widest. In addition, figure 1 shows the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece. In figure 1, this position on the surface of the middle piece is shown with reference sign "X".

[0023] Figure 2 shows the rib reference point obtained by removing the spinal column.

[0024] Figure 3 shows a schematically overview of the apparatus of the invention, including the conveyor, the middle piece placed on the conveyor, stabilising means, an optical recording device, and cutting tool.

[0025] Figure 4 shows a preferred position of the recording device.

[0026] Figure 5 shows determination of the position (black crosses) on two of the ribs, the rib edge (small white crosses) and the position (large white cross) on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece. The cutting path goes through the determined positions.

[0027] Figure 6 shows determination of the position (black cross) on one rib, the rib edge (small white crosses) and the position (large white cross) on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece. The cutting path go through the determined positions.

[0028] Figures 7-10 discloses various features obtained with an agent used to obtain a digital representation of a longitudinal cutting path according to preferred embodiments of the invention.

[0029] The present invention will now be described in more detail in the following. Detailed description of the invention

[0030] Definitions:

[0031] Prior to discussing the present invention in further details, the following terms and conventions will first be defined:

[0032] The term "dorsal side" refers to the part of the middle piece closest to the spinal column. The dorsal side is known as the loin in pork, and as the rib, short loin and sirloin in beef and lamb. In the context of the present invention, when referred to "loin" it is to be understood as the dorsal side of a middle piece of all kinds of mammals where middle dividing can be used and should not be limited to pork meat.

[0033] The term "ventral side" refers to the part of the middle piece away from the spinal column. The ventral side is known as the belly, spare rib, or side in pork, as the plate or flank in beef and as the breast and flank in lamb. In the context of the present invention, when referred to "belly" it is to be understood as the ventral side of a middle piece of all kinds of mammals where middle dividing can be used and should not be limited to pork meat.

[0034] The term "half-carcass" refers to the half of a slaughtered animal where the animal has been split in two parts through the spinal column along the sagittal plane. The half carcass includes a part of the spinal column.

[0035] The term "Longitudinal direction of the middle piece" refers to the orientation or direction from head to tail of an animal or vice versa.

[0036] The term "fillet" refers to the longissimus muscle group on the dorsal side of the carcass.

[0037] The term "rib" and "a position on at least one rib" refers in the context of the present invention both to a rib as such but also to the gap between ribs. The term "rib head" refers to the area of the upper part of the ribs and the skilled person would know what is referred to by the term "rib head". The rib head is the bulge on the rib, ending in the joint to the vertebrae. The rib head is shown as 6 in figure 2.

[0038] The term "rib edge" refers to a geometrical feature of the edge of the middle piece obtained by removing the spinal column of a carcass into, i.e. obtained by cutting through the rib head. In figure 2, different rib edge positions are shown where the dotted line 5 is obtained by cutting the spinal column through the dotted line and the lines 7, 8 are obtained by cutting the spinal column through the dashed lines 7,8, respectively, intersect the rib bone edge towards the lung cavity. The rib edge is a 3D path following this cut through all the ribs.

[0039] The dotted line 5 shows the ideal cutting line for the process of removing the spinal column and passes approximately through the middle of the rib head. The line 9 is the sagittal split plane. The part between the dotted line 5 and the line 9 is removed by a cutting device for removing the spinal column.

[0040] The term "ideal rib edge" is defined as the rib edge obtained when removing the spinal column through the dotted line 5 in figure 2. However, if a spinal column is removed by cutting higher or lower than the dotted line 5, the ideal rib edge is still defined by the ideal spinal column cut, and hence the ideal rib edge is in figure 2 shown as 5. The ideal rib edge is the cutting line obtained by the optimal cutting of the spinal column through the middle of all the rib heads.

[0041] The term "rib reference point" refers to a reference point from where the length of a rib can be determined. The rib reference point may be for example:

[0042] - an anatomical feature, such as the position located in the transition between rib head and rib bone

[0043] - a geometrical feature, such as the rib edge

[0044] - the ideal rib edge

[0045] The term "hip point" refers to a reference point describing the position of the fillet where it is widest. The "hip point" is determined as an output from a software agent on basis of the entire piece and has no direct connection to a specific anatomical feature except that the software agent has learned that, given a total image of a middle piece, this is where the fillet is widest. The hip point is shown in figure 1 with reference sign "Y". The fat layer is adjacent the fillet and hence also adjacent the hip point.

[0046] Method of the invention:

[0047] In the method according to the invention the middle part of a half carcass can be divided into a dorsal part (loin part) and a ventral part (belly part) by one cut. Further, the method of the present invention provides cutting of the middle part of a half carcass into a loin and belly part where the cutting is close to the fillet, but without cutting the fillet.

[0048] Figure 1 shows a side view of a middle piece of a half carcass where the loin part (1) and the belly part (2) is shown. Further, figure 1 shows the fillet (3) in the loin part (1). The fillet is not visible from the surface of the meat. When cutting the middle piece into a loin part and belly part, it is desired to make the cut as close to the fillet as possible but without cutting into the fillet. This is done by cutting through the fat layer (4) adjacent the fillet (3). In figure 1, the position on the surface of the middle piece (which is offset the fat layer) is shown with reference sign "X". Further, figure 1 shows the hip point with reference sign "Y".

[0049] In some embodiments of the invention, it is required to provide a cutting into a loin part and a belly part where the length of the ribs must be fixed. Hence, the length of the ribs (loin side) must be measured from the cut end.

[0050] In the method of the present invention, middle pieces of a half carcass is conveyed on a conveyor, where the middle piece is placed on the conveyor with the skin side downwards.

[0051] The carcass is preferably from a mammal selected from the group consisting of pork, cattle, sheep, horse, wild boar and bison, preferably pork, cattle, sheep and horse. More preferably, the carcass is from a mammal selected from the group consisting of pork and cattle. The conveyor is selected from the group consisting of a roller, a conveyor belt or holding means where the middle piece is conveyed by holding / gripping for example the spinal column, preferably a roller or conveyor belt.

[0052] The conveyor preferably comprises at least two conveyors placed close to each other in the longitudinally direction, but placed with a gap or slot between them, see figure 3. The two conveyors (10, 11) can be referred to as in-going conveyor (10) and the out-going conveyor (11). The term "in-going conveyor" refers to the conveyor before cutting and the term "out-going conveyor" refers to the conveyor after cutting. However, the conveyor may also be comprising two conveyors located parallel to each other with a gap and a cutting tool placed in between.

[0053] The middle piece (13) is placed on the conveyor such that the longitudinally direction of the middle piece is in the direction of the conveyor. It is not necessary for the middle piece's longitudinally direction to be parallel with the edge of the conveyor. The cutting tool can compensate for this when the cutting path is determined.

[0054] In embodiments wherein the middle piece of a half-carcass is arranged on a conveyer, the conveyer may preferably comprise an encoder providing data on movements of the conveyer and thereby the movement of the middle piece.

[0055] In the gap or slot between the two conveyors is placed a cutting tool (14), see figure 3. The cutting tool (14) cuts the middle piece into a loin part and a belly part and may be e.g. a band saw, a band knife, a circular cutting blade, a reciprocating cutting blade, or water-jet cutting. Preferably, the cutting tool is a band saw.

[0056] Hence, the conveyor comprises a gap or slot in the transverse direction, i.e. across the conveyor where the cutting tool is placed.

[0057] The cutting tool (14) is digitally controlled by a computer controlling cutting of the middle piece longitudinally along the determined cutting path. The cutting tool may be servo- powered. The servo powered cutting tool is controlled by a controller (16) such that the cutting tool can be moved sideways in the gap between the two conveyors. In another embodiment of the invention, the cutting tool is placed on a movable robotic arm that is controlled by a controller such that the cutting tool can be moved sideways in the gap between the two conveyors. This is also shown in figure 3. The movable robotic arm provides the cutting tool to move sideways in the gap so that the cutting tool follows the determined cutting path to eventually cut the middle piece into a loin part and a belly part.

[0058] The method of the invention involves determining a cutting path for longitudinal cutting of the half carcass comprising a step of determining a digital representation of a cutting path for longitudinally cutting of the middle of a half carcass. This involves the use of a software agent (17) being trained to locate a fat layer adjacent the fillet in a digital representation of a middle piece. The method also involves providing one or more optical recording device(s) (15) for providing the digital representation of the middle piece, and in particular determining the at least one rib and a rib reference point of the middle piece.

[0059] The optical device(s) (15) preferably, by use of suitable means, include, for example cameras and / or equipment, which generate, are configured for, or are capable of taking video images, stereo vision, scanning, time-of-flight measurements, X-rays, and / or structured light.

[0060] In an embodiment of the invention, the method comprises moving the middle piece of the half-carcass, while supported by a conveyer, along a longitudinal direction of the middle piece, providing image data of the moving middle piece with the one or more optical recording device(s), including at least the ribs.

[0061] Accordingly, in preferred embodiments of a method according to the present invention the middle piece may be arranged on a conveyor and the position of the middle piece on the conveyor may be stabilized, for example by stabilising means (12). Such stabilising means may include spikes placed on the conveyor. The spikes will stabilise the position of the middle piece on the conveyor such that the middle piece is not moving in relation to the conveyor when cut by the cutting tool. The present invention is capable of handling both left and right sides of middle pieces of half-carcasses. The agent will determine based on the digital representation of the middle piece of the half carcass whether it is a left side or a right side.

[0062] In the method of the present invention, a position on the at least one rib from the rib reference point is determined in the digital representation by the software agent as a user provided length from the rib head / rib edge.

[0063] The position of the cut in the at least one rib is not a fixed point but can vary dependent on which cut is desired. For example, the position on the at least one rib could be from 30mm to 100mm from the rib reference point, preferably from 45mm to 75mm.

[0064] In order to determine at cutting line, it is only necessary to determine a position on one rib and a position on the surface of the middle piece being offset the fat layer adjacent the fillet. However, in a preferred embodiment of the invention, the positions of at least two ribs from a corresponding rib reference point are determined.

[0065] The at least two ribs are in a distance of at least 3 ribs from each other, such as at least 4, 5 or 6 ribs from each other.

[0066] In a further embodiment of the invention, the at least two ribs include one of the 3 first ribs and one of the 5 last ribs of the middle piece. Preferably, the at least two ribs are one of the 2 first ribs and are one of the 3 last ribs in the middle piece. Most preferably, the at least two ribs are the first rib and the last rib of the middle piece.

[0067] In addition, more than two ribs could be determined in the digital representation, such as 3, 4, 5 or more ribs.

[0068] By the term "last rib" or "last ribs" is / are in the context of the present invention meant the posterior ribs, i.e. the rib / ribs closest to the hip of the carcass. The term "first rib" or "first ribs" refer to the anterior ribs, i.e. the rib / ribs closest to the neck.

[0069] The positions of two or more ribs do not need to be in the same distance to the corresponding rib reference point. Typically, the position of the rib closest to the first rib is in a distance to the rib reference point that is shorter than the distance between the position and rib reference point and the second rib that closest to the last rib.

[0070] The method of the present invention also includes locating a position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is in the side of the fillet closest to the ventral side of the middle piece. Said position on the surface of the middle piece of the half carcass is determined by using one or more optical recording device(s) and a trained software agent.

[0071] The position on the surface of the middle piece being offset the fat layer adjacent the fillet is placed on the side of the middle piece opposite the skin side. Hence, the position on the surface of the middle piece is having a relation to the fat layer, preferably an anatomical relation to the fat layer since it is a proxy to the fat layer.

[0072] The position on the surface of the middle piece is offset the fat layer, i.e. the position is on the surface of the middle piece in a distance from the fat layer, i.e. the position on the surface of the middle piece is placed above the fat-layer (see reference sign "X" in figure 1).

[0073] The offset of the position on the surface of the middle piece to the fat layer depends on the characteristics of the individual middle piece and the desired cutting angle. However, typically the offset from the position on the surface of the middle piece to the fat layer is 20-40 mm.

[0074] The position on the surface of the middle piece being offset the fat layer adjacent the fillet is preferably a position placed vertically above the fat layer, such as in a straight line above the fat layer. However, the position on the surface of the middle piece may also be a position not directly vertically above the fat layer. This could for example be if the angle of the cutting tool is not 90 degrees to the plan of the conveyer.

[0075] For example, the position on the surface of a middle piece as referred to in the present invention is located offset the location of the fat layer, such as located vertically offset above the fat layer. The position on the surface of the middle piece adjacent to the fat layer is besides from being shown in figure 1 with reference sign "X", also shown in figures 5 and 6 with the large white cross and in figures 9 and 10 with the black crosses.

[0076] The position on the surface of the middle piece is determined by using the trained software agent.

[0077] The term "software agent" refers to a software implemented algorithm, such as an intelligent algorithm, such as Convolutional Neural Network (CNN), which may be trained using various algorithms such as presently known as Adam, Smac, One- cycle, for example in combination with transfer learning and data augmentation. Different types of networks are usable in connection with the present invention, such as an internal network and an architecture presently known as ResNetl8, pre-trained on a dataset, such as a dataset presently known as ImageNet. The software agent may be capable of, based on a digital representation of a middle of a half carcass, to locate one or more points on and / or structures, such as rib, rib heads, rib edges or the like, in the middle of a half carcass. The software agent may also be capable of determining a digital representation of a cutting path for longitudinal cutting of the middle of a half carcass based on the located point(s) and / or structures.

[0078] The term "digital representation" refers to representation of a physical object, such as a middle of a half carcass, which representation is computerised. Preferred embodiments of digital representation in connection with the present invention are bit map images, 3-dimensional scans, such as point cloud based and / or mesh based. The bit map images and / or the 3-dimension scans may be colour coded, black and white coded and / or grey shaded coded. The term "digital representation of a longitudinal cutting path" refers to a cutting path determined in the digital representation of the middle of a half carcass. Such a cutting path may be a line or a plane along which the cutting is to perform a cutting. The cutting path may be expressed in co-ordinates in a co-ordinate system assigned to the physical position of the middle of the half carcass. To obtain such co-ordinates, sensors may be used that register e.g. the leading edge of the middle piece, and the co-ordinates in the digital representation are obtained based on this registration of the middle piece. Alternatively, the co-ordinates are obtained from the digital representation of the middle of the half carcass by including one or more markers on a conveyor on which the middle of the carcass is located when the digital representation is obtained. Such markers serve the purpose of providing a link between the digital representation and the physical location of the middle of the half carcass on the conveyor. As an example, two distanced markers may be visible by the optical recording device and the positions of the two distanced markers relatively to the cutting tool is known, whereby an algorithmic transformation can be provided between the digital representation and the physical object and / or a co-ordinate system assigned to the physical position of the middle of the half carcass may be used the digital representation.

[0079] The ideal cut of the middle piece into the loin part and belly part is by separating the fillet from the ventral muscles. Hereby, the fillet is in the dorsal part of the middle piece. It is important not to cut into the fillet as it will decrease the value of the meat piece.

[0080] The fillet is widest at the hip point, and therefore the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece is preferably determined to be close to the hip point. The fat layer is adjacent the hip point and therefore the trained software agent determines the position on the surface of the middle piece based on the fat layer and indirectly the hip point. Both the fat layer and the hip point are not visible and can only be found by the trained software agent. If the cut of the middle piece is performed in an off-set from the position on the surface of the middle piece being offset the fat layer adjacent to the fillet inside the middle piece and close to the hip point, the fillet is not cut. In the context of the present invention, the term "off-set" refers to a distance from a certain point.

[0081] The off-set is according to the present invention either:

[0082] - a first off-set which is the off-set between the position on the surface of the middle piece and the cutting line (entry point for cutting). The first off-set is essentially a horizontal distance.

[0083] - a second offset which is the offset between the position on the surface of the middle piece and the fat layer. The second offset is essentially a vertical distance.

[0084] First off-set:

[0085] The off-set (first off-set) from the position on the surface of the middle piece to the cutting line may for example be 0 to 10 mm, i.e. the cutting may be in the determined position (off-set is zero) or the cutting is in a distance of up to 10 mm to the determined position. If the off-set is zero, the risk of cutting into the fillet is higher than if the off-set is set to 10 mm. Preferably, the off-set to the position is set to 3-10 mm, more preferably 5-7 mm.

[0086] The first offset is a deliberate off-set and an off-set that is adjustable, i.e. an adjustable off-set.

[0087] Second offset

[0088] The offset (second offset) from the position on the surface of the middle piece to the fat layer adjacent the fillet may for example be 20-40 mm. This offset is an anatomical feature of the individual meat piece.

[0089] The position on the surface of the middle piece being offset the fat layer adjacent to the fillet inside the middle piece is located by using the trained software agent. When the middle piece is moved on the conveyor, one or more optical recording device(s) provides a digital representation and based on the software agent comprising stored data of earlier cuts, the software agent will based on the digital representation and the stored data / training set determine the location of the position. The position on the surface of the middle piece being offset the fat layer adjacent to the fillet inside the middle piece and close to the hip point is not visible and can only be determined by use of the trained software agent.

[0090] The training has involved cutting of 3000 middle parts of a half carcass into a loin part and a belly part, followed by measuring the distance of the cut to the ideal cut, i.e. measuring the mistakes in the cuts. The data is stored in a computer and a neural network is let to learn from the mistakes made (manually measured distance to ideal cut), and compensate for the mistakes, by training it to point to the position where the cut should have been instead. Based on these training data, the controller can based on the image data determine a correct cut close to the fillet in the loin part of the middle piece, but not cutting into the fillet.

[0091] In the method of the present invention, a longitudinally cutting path is determined going between the determined position on the at least one rib and an off-set (first off-set) to the located position on the surface of the middle piece offset (second offset) the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece.

[0092] When the cutting path is determined, a computer controlled cutting tool cuts the middle piece of the half carcass longitudinally along the determined cutting path.

[0093] The cutting will typically not be parallel to the edge of the conveyor. The reason for this can be that the middle piece is not placed parallel to the edge of the conveyor edge or the cutting path determined is not parallel to the conveyor edge because of the anatomical characteristics of the middle piece. To compensate for the cutting not being parallel to the conveyor edge, the cutting means may be movable in a sideways direction perpendicular to the longitudinally direction of the middle piece, i.e. the cutting tool is preferably movable from side to side of the transverse direction of the conveyor. Hence, in a preferred embodiment of the invention, the cutting tool is movable in a sideways direction perpendicular to the longitudinal direction of the conveyor. In an embodiment, the cutting path between the position of the at least one rib and the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece is in a straight line or is in a curved line.

[0094] In a further embodiment, the cutting path is in an off-set (first off-set) to the at least one rib being 0-20 mm and in an off-set to the position on the surface of the middle piece being offset (second offset) the fat layer adjacent the fillet inside the middle piece being 0-10mm.

[0095] The determination in the digital representation and by use of said software agent of at least one rib is preferably determination of at least two ribs. If a position on at least two ribs are determined, the cutting path between the position of the at least two ribs is a straight line or a curved line. Further, the cutting path between the position of the posterior rib and the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece is a straight line or a curved line.

[0096] Preferably, the at least two ribs are the first rib and the last rib. In some cuts, it is preferred to make a straight line where it in other cuts are preferred to make a curved line. A curved cutting line may for example improve the yield obtained as compared to the cut being a straight cutting line. The circular cutting blade may be preferred if the cutting line is a straight line, while a band saw is preferred for making a curved cutting line.

[0097] The method of the present invention should not be limited to either a straight cutting line or a curved cutting line since both can be used.

[0098] In another embodiment, the cutting path between the position of the rib closest to the hip point (for example last rib) and the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece is in a straight line or is in a curved line. In some cuts it is preferred to make a straight line where it in other cuts are preferred to make a curved line. Preferably, the cutting path between the position of the rib closest to the hip point and the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece is a curved line, since the form of the fillet may be curved. However, the method of the present invention should not be limited to either a straight cutting line or a curved cutting line since both can be used.

[0099] The cutting path from the rib closest to the hip point to the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece is typically a straight cutting line having an off-set to the hip point of 5-7 mm.

[0100] Apparatus:

[0101] The apparatus according to the present invention is described in view of the accompanying figures.

[0102] An apparatus according to the present invention for longitudinal cutting of middle pieces of a half carcass into a ventral part and a dorsal part.

[0103] With reference to figure 3, the apparatus comprises a conveyor (10, 11) for conveying a middle piece (13) of a half carcass along a conveying path with the skin side facing downwards.

[0104] The conveyor comprises preferably at least two conveyors placed with a gap between them. Hence, the conveyor is preferably comprising an ingoing conveyor (10) and an outgoing conveyor (11) placed with a gap in between. The ingoing conveyor is the conveyor before cutting of the middle piece and the out-going conveyor is the conveyor after cutting of the middle piece.

[0105] The conveyor may be a roller, a conveyor belt or holding means where the middle piece is conveyed by holding / gripping for example the spinal column, preferably a roller or conveyor belt.

[0106] In an embodiment of the present invention, the conveyor comprises stabilizing means (12), such as spikes for stabilizing the middle piece on the conveyor.

[0107] Further, the apparatus comprises one or more optical recording device(s) (15) configured for providing a digital representation of the middle piece (13) of the half carcass while being placed on the conveyor (10, 11).

[0108] The apparatus also comprises a software agent (17) trained to determine from the digital representation of the middle piece: a) at least one ribs and a rib reference point of the middle piece; b) a position on the at least one rib a length from the rib reference point; c) a position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece; d) a cutting path going through the determined position on the at least one rib and an off-set to the determined position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece;

[0109] The apparatus also comprises a computer controlled cutting tool (14) for cutting the middle piece of a half carcass in the longitudinal direction along a predetermined cutting path, and the apparatus comprises a controller (16) for digitally controlling the cutting tool to cut the middle piece of the half carcass longitudinally along the determined cutting path. Figure 3 shows that the cutting tool is located in a gap between the ingoing conveyor (10) and the outgoing conveyor (11). The cutting tool can be moved in a sideways direction such to provide a correct cut along the cutting path. This movement is controlled by a controller (16). The conveyors may also be placed in parallel with a gap in between and the cutting tool placed in the gap.

[0110] The optical recording device(s) (15) preferably, by use of suitable means, include, for example cameras and / or equipment, which generate, are configured for, or are capable of taking video images, stereo vision, scanning, time-of-flight measurements, X-rays, and / or structured light. Further, the one or more optical recording device(s) is placed in a position above the conveyor to provide digital representation of the middle piece of the half carcass.

[0111] In an embodiment of apparatus of the invention, the one or more optical recording device(s) (15) is / are at least one camera and / or equipment configured for, or capable of, taking video images, stereo vision, scanning, time-of-flight measurements, X-rays, and / or structured light. For example, the camera is a 3D camera providing 3D images.

[0112] In another embodiment of the invention, the one or more optical recording device(s) is / are a monochrome imaging device and / or hyperspectral imaging device and / or a multispectral imaging device. For example, the one or more optical recording device(s) is / are a CCD, EMCCD, CMOS, or other digital imager based digital camera, such as a digital camera recording colour or monochrome images.

[0113] In an embodiment of the present invention, the apparatus comprises at least two optical recording devices.

[0114] In a further embodiment of the invention, the apparatus comprises one or more light sources to illuminate the middle piece. Illumination with a suitable light source can optimise the digital representation of the middle piece obtained by the optical recording device(s).

[0115] The cutting tool (14) is selected from the group consisting of e.g. a band saw, band knife, a circular cutting blade, a reciprocating cutting blade, or water-jet cutting, and the cutting tool is preferably placed in the gap between the two conveyors.

[0116] Preferably, the cutting tool is servo-powered and controlled by the controller (16). In other embodiments, the cutting tool is placed on a movable robotic arm controlled by the controller (16).

[0117] Figure 4 shows the preferred position of an optical recording device in relation to the middle piece. Hence, the optical recording device should preferably be placed above the middle piece such that a digital representation can be obtained of the entire inside of the middle piece, including ribs, rib edge and rib head. In figure 4, the dashed camera will not be able to locate the rib edge because the camera is not placed correctly in relation to the middle piece.

[0118] Figure 5 shows a middle piece and positions (black crosses) on two ribs determined by the agent. Figure 5 also shows the position (large white cross) on the surface of the middle piece being offset the fat layer adjacent to the fillet insider the middle piece. A cutting path is determined going through the two positions on the ribs and the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece. In figure 5, the positions (black crosses) on the ribs are on the first rib and one of the middle ribs. Figure 6, shows the position (black cross) of one rib (first rib) and the position (large white cross) on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece.

[0119] It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention. Hence, the technical features disclosed in connection with the method also apply to the apparatus and vice versa.

[0120] In the following, detailed descriptions of digital implementations of various embodiments are disclosed.

[0121] On finding the cutting curve:

[0122] Finding of the cutting curve may comprise a number of steps and aims at finding the least two control positions used for generating the cutting curve for the cutting tool.

[0123] The control positions used are typically one or more of:

[0124] 1) At least one position on the ribs, controlling the length of the ribs, and one position in the fat layer adjacent the fillet to find the position on the surface of the middle piece. The position in the fat layer is preferably being close to the hip point which is the position of the widest part of the filet. These at least two positions may in general not make a straight line but allow the goals in both rib and hip end to be achieved. Since the positions are found from geometrical and anatomical features on the piece, they will follow the piece if it is placed at an angle on the conveyor.

[0125] 2) Two positions found from a fixed distance from the back of the piece, ignoring all anatomical features. This is a simpler cut and will not be optimal in terms of the rib lengths and the filet position, but it will, as above, follow the piece if it is e.g. placed at an angle on the conveyor. Also, products exist where this is the wanted cut. 3) A command to skip the piece, where the saw is moved to the side of, typically completely outside, the conveyor. This is used if the piece cannot be cut in a good way, e.g. if it is placed wrong on the conveyor, and would be wrecked if the saw tried to cut it, or if the analysis cannot identify the wanted control positions to cut the piece correctly.

[0126] 4) A command to make the saw stay where it is, and not move at all. This is used if e.g. two pieces are placed so close together that it is not physically possible to move the saw before the next piece arrives. As moving the saw at too high velocity in the meat will likely damage the saw blade, it is better to cut the next piece sub-optimally.

[0127] The steps, leading to a class of control positions, will be described in detail below.

[0128] On fixed width, found geometrically

[0129] Reference is made to Fig. 7. Standard 3D geometry is used to find the edge of the piece closest to the conveyor edge (black dots). From these points, projected vertically down onto the conveyor surface (grey dots) one or more fixed distances are measured towards the center of the conveyor (thin dashed lines) perpendicular to the piece orientation on the conveyor (dashed lines on conveyor plane). These lines are the projected vertically up to the surface of the meat (black crosses).

[0130] The fixed width control positions are used for item 2 above, as well as if the other control positions cannot be identified correctly. In this case, the piece may be split sub-optimally in an anatomical sense, but it is possible to split it, if the end user selects this mode in the recipe setup. This is preferably informed to the user interface as a fall back recipe.

[0131] On rib control positions, found geometrically

[0132] Reference is made to fig. 8. Rib control positions are also found by using 3D geometry: Identifying the rib end (done in this implementation by using the hip point agent, which will identify a point in the opposite end of the piece), identifying the edge of the previous cut (large black crosses) (separating the spine from the rest of the carcass) and optimally identifying the rib heads in the 3D view or otherwise placing a point at the first and last rib. These points are used as the rib reference positions for each rib. From these rib reference positions, the first point on the meat surface at a specific distance is found. E.g. by drawing a circle at a user specified radius around the edge point and finding the point where the circle hits the meat surface (large grey crosses). This point is the rib control position.

[0133] Alternately, all of the rib edge points may be used to find a multitude of distance points, preferably with a continuously varying distance from the first to the last rib).

[0134] Selection of the method for finding the cutting curve in the rib end is typically available to the end user in the user interface.

[0135] On hip point, found by a neural network

[0136] The position of the fillet inside the piece may be found by training a neural network to identify the correct position in a Z height image transformed into a 2D height map. This means that, where the geometrical analysis in 3D in the two previous steps is working directly on the 3D points, the neural network ignores the X information (distance in mm across the piece) in favour of pixels that are only neighbours.

[0137] This design choice allows the direct use of a wide range of already existing neural networks. In particular, it allows the use of pre-trained networks far larger than what we would have been able to train on the relatively small data set we have. The network is in the preferred embodiments using this representation presented in Fig. 9 as an alternative to the representation shown in Fig. 10.

[0138] In the embodiment disclosed in Fig. 10, the black cross marks the found position on the surface of the middle piece above the fillet membrane. It is noted that the filet is not visible on the surface, but the network has learned where the fillet is hidden based on thousands of similar images, where the measurement of the cutting error from a different algorithm has been used to place a training cross on a similar image. The 2D image in figure 9 is scaled down and the background is removed. This is done to make the training faster and to allow the use of data augmentation to multiply the number of training images obtained from pieces manually measured. Different methods for training the network for optimal performance, since the training data was so expensive to make, but the task is a standard Convolutional Neural Network (CNN) application as soon as the training data has been processed in 3D to show the location of the right pixel on the surface of the meat - the pixel which the saw should hit at the selected angle to just slice through the membrane surrounding the filet.

[0139] In one implementation, the network is trained from a ResNetl8 model pre-trained on ImageNet. The training algorithm used was Adam and One-cycle. Without being bound by theory, other network topologies and other training algorithms could be used to obtain similar results.

[0140] After the CNN has found the most likely pixel for point X on the surface in the 2D image, the pixel is transformed back to 3D coordinates for the points X and Y like the other control positions, and can be used for generating the cutting curve.

[0141] On pre-analvsis neural network

[0142] Standard CNN classifier, also using with a Z height image transformed to a 2D height map as input, but used for dividing the pieces into one of several classes:

[0143] • Cuttable

[0144] • Has not been cut in previous steps, so ribs should be cut differently, but hip point is still valid

[0145] • Has foreign matter inside the cavity, so we cannot trust the control positions. This piece must be cut at fixed width

[0146] • Is turned in different ways, so should either be skipped or cut in yet another way

[0147] A classifier is software agent for determining which class an entire image belongs to. The bullet list above each represents such a class. Therefore, by running a classifier on the image, it is determined how to optimally handle the piece in the "real" analysis software. A CNN classifier is well known to the person skilled in the art of software. This network may be used for handling situations where it can be known in advance that the control point steps (see above items 1-4) generate bad results. One example is a piece where the spine has been cut off, but not removed from the cavity. The detection of the rib control points cannot be done for this piece since the camera is not able to see the relevant surface. It was found by the inventors of the present invention that it was easier to detect in advance that the piece is not cuttable, and it is valuable to the end user to know the reason (spine in piece) in a user facing statistics module, instead of trying to determine whether the analysis result is valid.

[0148] On generation of saw curve

[0149] The output of the pre-analysis and the available output from the control position analysis steps are preferably combined according to logic instructions in a user- editable cutting recipe to select a set of control positions. The set of control positions are preferably connected with straight lines into a piecewise linear curve in 3D.

[0150] The piecewise linear curve is then combined with a selectable cutting angle and cutting offsets to generate the final cutting curve, preferably being a 2D piecewise linear curve on the conveyor surface, which is transferred to the digitally controlled saw as a set of positions, typically one position across the conveyor for each few mm of product, in total forming a sampled 2D piecewise linear curve.

[0151] Other methods of transferring the result to the saw are possible, including other sampling distances or the transferring of parameters for generation of the curve using e.g. Bezier, polynomials, quadratic or other curve generating algorithms, and could be used to get very similar results.

[0152] On synchronization of saw and image analysis

[0153] In a preferred embodiment, the synchronization of the analysis results, placed in the camera coordinate system, is synchronized to the conveyor movement by use of a common encoder for knowing the movement of the conveyor and triggering of each of the lines of the 3D image taken by a line scanning camera. A separate sensor is preferably used for triggering the saw to mark the beginning of the curve. Other methods of synchronization could be used, including using the conveyor encoder directly, but the separate sensor is simple to implement and robust towards drift from noise pulses on the encoder signals, which would need to be kept in sync between the computer running the vision system and the digitally controlled saw.

Claims

Claims1. A method for longitudinal cutting of middle piece of a half carcass into a dorsal part and a ventral part, said method comprising the following steps: i) conveying a middle piece of a half carcass on a conveyor, wherein the middle piece of the half carcass is placed on the conveyor with the skin side downwards; ii) providing a software agent being trained to locate in a digital representation of a middle piece of a half carcass a position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece; iii) determining a digital representation of a cutting path for longitudinal cutting of the middle of the half carcass by: a) providing by use of one or more optical recording device(s) a digital representation of the middle piece of the half carcass placed on the conveyor; b) determining in said digital representation and by use of said software agent: a. at least one rib and a rib reference point of the middle piece of the half carcass; b. a position on the at least one rib from the rib reference point as a user provided length from the rib reference point; c. the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece; d. a digital representation of a longitudinally cutting path between an off-set to the determined position on the at least one rib and an offset to the located position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece;iv) digitally controlling a computer controlled cutting tool to cut the middle piece of the half carcass longitudinally along the determined cutting path by said cutting tool receiving said digital representation of a longitudinal cutting path.

2. The method according to claim 1, wherein the said software agent is a software implemented algorithm, such as an intelligent algorithm, such as an Al agent, preferably trained using a pre-obtained dataset comprising digital images of various cuttings of middle pieces of half carcasses.

3. The method according to claim 1, wherein the cutting path between the position of the at least one rib and the position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece is in a straight line or is in a curved line4. The method according any of the claims 1 to 3, wherein the cutting path is in an off-set to the at least one rib being 0-20 mm and in an off-set to the position a on the surface of the middle piece having a relation to the fat layer adjacent the fillet inside the middle piece being 0-10 mm.

5. The method according to any of the claims 1 to 4, wherein the determining in said digital representation and by use of said software agent is of at least two ribs.

6. The method according to any of the claims 1 to 5, wherein the conveyor comprises stabilising means.

7. The method according to any of the claims 1 to 6, wherein the carcass is from a mammal selected from the group consisting of pork, cattle, sheep, horse, wild boar and bison.

8. An apparatus for longitudinal cutting of middle pieces of a half carcass into a ventral part and a dorsal part, said apparatus comprising: i) a conveyor for conveying a middle piece of a half carcass along a conveying path with its skin side facing downwards;ii) one or more optical recording device(s) configured for providing a digital representation of the middle piece of the half carcass while being placed on the conveyor; iii) a software agent being trained to determine from said digital representation of a middle piece: a) at least one rib and a rib reference point of the middle piece; b) a position on the at least one rib a length from the rib reference point; c) a position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece, where the fat layer adjacent the fillet is on the side of the fillet closest to the ventral side of the middle piece; d) a cutting path going through an off-set to the determined position on the at least one rib and an off-set to the determined position on the surface of the middle piece being offset the fat layer adjacent the fillet inside the middle piece; iv) a computer controlled cutting toll for cutting the middle piece of half carcass in the longitudinal direction along the determined cutting path; v) a controller for digitally controlling the cutting tool to cut the middle piece of the half carcass longitudinally along the determined cutting path.

9. The apparatus according to claim 8, wherein the conveyor comprises at least two conveyors placed with a gap between them, and wherein the cutting tool is placed in the gap between the two conveyors.

10. The apparatus according to any of the claims 8 to 9, wherein the conveyor comprises stabilizing means.

11. The apparatus according to any of the claims 8 to 10, wherein the one or more optical recording device(s) is placed in a position above the conveyor to provide digital representation of the middle piece of the half carcass.

12. The apparatus according to any of the claims 8 to 11, wherein the one or more optical recording device(s) is / are at least one camera and / or equipment configured for, or capable of, taking video images, stereo vision, scanning, time- of-flight measurements, X-rays, and / or structured light.

13. The apparatus according to claim 12, wherein the camera is a 3D camera providing 3D images.

14. The apparatus according to any of the claims 8 to 13, wherein the one or more optical recording device(s) is / are a monochrome imaging device and / or hyperspectral imaging device and / or a multispectral imaging device.

15. The apparatus according to any of the claims 8 to 14, wherein the one or more optical recording device(s) is / are a CCD, EMCCD, CMOS, or other digital imager based digital camera such as a digital camera recording colour or monochrome images.

Images