The present invention relates to a measuring system or a scanning system and a method for determining the presence and/or positon of bones in a meat piece and especially of bones located near the edge in a meat piece. The measuring system may be a part of a larger system for removing the detected bones, such as where the bones are

automatically removed, e.g. by an industrial robot.

Background of invention

When processing meat such as when cutting carcasses or part hereof into smaller pieces bones may be removed from the cuttings before further processing or before a meat piece is ready for sale.

Today removal of bones from cuttings is in many instances performed by manually removal of the bones where an abattoir worker cuts free the bones with a handheld knife. Such work can be strenuous and may be performed at high speed and the workers may obtain work-related injuries due to the repetitive work.

For some kinds of cuttings machines has been developed which in a pure mechanically pattern remove bones from cuttings. Such machines are often removing a predetermined amount of a cutting which may not be adjusted due to the variation in the meat cuttings such as variation in size of the bones and of the meat cuttings

themselves. Too much meat may be removed in such a bone removal, which may add up to a huge amount of products which are sold at a lower price due to a lower weight.

In the automation of the process of removing bones from carcasses and cuttings, measuring or scanning systems are required to obtain information which can be used e.g. when the bone removing part of a system such as a robot removes the bones. GB 2446822 describes detecting foreign bodies such as bone in meat products and the like using an optical imaging technique. Objects such as chicken fillets are moved along a conveyor. An imaging device is able to take a first image of the objects backlit by a light source, at a first wavelength. Second light sources are arranged so that

simultaneously the imaging device is able to take a second image of the objects based on light reflected from the surface of the objects at a second wavelength. A processor may be adapted to identify dark regions in the two images.

Herein is described a measuring or scanning system for determining presence and/or position of bones in a meat piece and especially of bones located near the edge in a meat piece. The measuring or scanning system is based on electromagnetic waves, such as light, which should not pass the conveyor belt conveying meat pieces to be examined. The measuring system may be a part of a larger system for removing detected bones, where the bones are automatically removed by an industrial robot. Such a system may be a system for removing near the edge bones e.g. ribs from a belly piece. Summary of invention

The invention relates to a measuring system with sources for emitting electromagnetic waves such as light and receiving sensors such as cameras. Light of different

wavelengths such as blue/green light and red/infrared light can be directed towards a meat piece and the reflected blue/green light and the emitted red/infrared light can be registered such as by line scanning. From constructed images the position, lengths and angles of bones located near an edge of a meat piece can be determined. Such information can be communicated to e.g. an industrial robot which may remove the identified bones.

The measuring or scanning process performed by the measuring system may be performed while the one part of the measuring system and the meat piece is moving and the other part preferably is non-moving. Removal of bones may be performed on a stationary meat piece or on a meat piece being conveyed e.g. on a conveyor belt.

The invention thus relates to a measuring or scanning system for determining the presence and/or positon of at least one bone in at least one meat piece while the meat piece or the measuring system pass the location of each other such as when a meat piece is conveyed on a transport surface such as on a conveyer belt, and where the measuring system optionally further is for determining the length and/or orientation of the at least one bone, the system comprises

• At least one first source for emitting electromagnetic waves where the

electromagnetic waves are emitted from above and towards the meat piece when the measuring system is in function and such that the emitted electromagnetic waves is directed towards at least a first side of a meat piece,

• At least one second source for emitting electromagnetic waves where the

electromagnetic waves are directed towards at least a second side of the meat piece when the measuring system is in function, and where the second side is not a side in contact with the transport surface,

• At least one receiving sensor such as a camera facing towards the meat piece when the measuring system is in function and where the at least one receiving sensor receives and separates electromagnetic waves in at least two groups of wave ranges, and where the at least one receiving sensor receives electromagnetic waves being directed in a direction upward according to the meat piece, and the received and recorded electromagnetic waves are obtained from at least part of the meat piece,

• At least one processing unit such as a PLC for processing at least some of the electromagnetic waves received by the at least one receiving sensor and where at least two images or datasets are constructed from the at least two groups of wave length ranges and based on the at least two images or datasets the presence and/or position and optionally length and/or orientation of the at least one bone is determined.

The light used in the measuring system may be light waves in the blue or green region such as light with wave lengths of between about 430-500nm or 500-565nm and light waves in the red region including infrared region such as light with wave lengths of between about 620-1000nm.

A guide may guide a red light source along a side of a meat piece which is orthogonal to the upper side of the meat piece during the measuring process and such then the red light waves are directed towards the meat piece in a predetermined distance from the upper side of the meat piece. The guide can secure that this distance is constant along the entire meat piece.

Described is also a method for determining the presence and/or positon of at least one bone in at least one meat piece while the meat piece is conveyed such as on a conveyer belt and where the method optionally further is for determining the length and/or orientation of the at least one bone, the method comprises

• Conveying at least one meat piece on a transport surface of a conveyor belt,

• Directing electromagnetic waves such as blue and/or green wave lengths towards a first surface of the at least one meat piece,

• Directing electromagnetic waves such as red and/or infrared wave lengths

towards a second surface of the at least one meat piece and which is not from below,

• Receiving electromagnetic waves of at least one pre-determined wave range such as blue and/or green wave lengths and which are reflected from the first surface

• Receiving electromagnetic waves of at least one pre-determined wave range such as red and/or infrared wave lengths and which are transmitted through the meat piece and emitted from the first surface of the meat piece,

• Processing the received electromagnetic waves to construct at least two images or datasets which may be superposed over each other such that one image or dataset is constructed which indicates the presence and/or position of at least one bone in the meat piece.

Described is also how the measuring system may be combined with a system including an industrial robot and where this robot can remove bones such as ribs from a belly piece based on information communicated from the measuring system.

Brief description of figures

Fig. 1 is a schematic illustration with a top view of a measuring or scanning system and a working zone.

Fig. 2 is a schematic illustration with a side view of a measuring or scanning system and a working zone.

Fig. 3 is a schematic illustration with a transversal view of a measuring or scanning system.

Fig. 4 illustrates a handheld rib puller located in a start position above a belly meat piece for loosening a single rib. Fig. 5 illustrates a rib puller for an industrial robot, where the rib puller is in the start position.

Fig. 6 and 7 illustrates a rib puller for an industrial robot, where the rib puller is in the end position.

Fig. 8 is a schematic illustration of a belly piece with ribs where the skin is facing downward.

Fig. 9 illustrates directing light towards one side of a meat piece and receive light waves which has passed the meat piece.

Detailed description of the invention

An aspect of the invention relates to a measuring system for determining the presence and/or positon of at least one bone in at least one meat piece while the meat piece or the measuring system pass the location of each other such as when a meat piece is conveyed on a transport surface such as on a conveyer belt, and where the measuring system optionally further is for determining the length and/or orientation of the at least one bone, the system comprises

· At least one first source for emitting electromagnetic waves where the

electromagnetic waves is emitted from above and towards the meat piece when the measuring system is in function and such that the emitted electromagnetic waves are directed towards at least a first side of a meat piece,

• At least one second source for emitting electromagnetic waves where the

electromagnetic waves are directed towards at least a second side of the meat piece and which is not from below when the measuring system is in function,

• At least one receiving sensor such as a camera facing towards the meat piece when the measuring system is in function and where the at least one receiving sensor receives and separates electromagnetic waves in at least two groups of wave ranges, and where the at least one receiving sensor receives

electromagnetic waves being directed in a direction upward according to the meat piece, and the received electromagnetic waves are obtained from at least part of the meat piece,

• At least one processing unit such as a PLC for processing at least some of the electromagnetic waves received by the at least one receiving sensor and where at least two images or datasets are constructed from the at least two groups of wave length ranges and based on the at least two images or datasets the presence and/or position and optionally length and/or orientation of the at least one bone is determined.

The measuring system may be located on or connected to a conveyor belt to scan meat pieces such as belly pieces located on the conveyor belt. After scanning of a meat piece, it may be conveyed by a conveyor belt to a location where an industrial robot may loosen the bones.

It is believed that the measuring system will be most used for examination of meat pieces being conveyed on a transport surface such as on a conveyor belt and such that the measuring system when ready to use is a stationary measuring system mounted on a conveyor belt. The invention will be described as a stationary measuring system on a conveyor belt, but may as described above be a moving measuring system where the meat pieces is not moving during the examination, thus the description should be understood for both situations.

With a stationary measuring system the invention can be described to be a measuring system for determining the presence and/or positon of at least one bone in at least one meat piece while the meat piece is conveyed on a transport surface such as on a conveyer belt and where the system optionally further is for determining the length and/or orientation of the at least one bone, the system may comprise · at least one first source for emitting electromagnetic waves where the

electromagnetic waves are emitted from above and towards the transport surface and such that the emitted electromagnetic waves are directed towards at least a first side of the meat piece when the meat piece is being transported past the first source for emitting electromagnetic waves,

• at least one second source for emitting electromagnetic waves where the

electromagnetic waves are directed transversely across and close to the transport surface in a height above the transport surface such that the emitted

electromagnetic waves are directed towards at least a second side of the meat piece when this meat piece is being transported past the second source for emitting electromagnetic waves, and where the second side of the meat piece is a side not in contact with the transport surface,

• at least one receiving sensor such as a camera facing from above and towards the transport surface and which can receive and separate electromagnetic waves in at least two groups of wave ranges, and where the at least one receiving sensor receives electromagnetic waves being directed in a direction upward according to the transport surface, and the received or recorded electromagnetic waves are obtained from at least part of a meat piece being transported on the transport surface,

• at least one processing unit such as a PLC for processing at least some of the electromagnetic waves received by the at least one receiving sensor and where at least two images or datasets are constructed from the at least two groups of received wave length ranges and based on the at least two images or datasets the presence and/or position and optionally length and/or orientation of the at least one bone is determined.

For the at least one receiving sensor it is to be understood that when receiving electromagnetic waves this also means that the electromagnetic waves are recorded by the system making it possible for a processing unit to analyse the recorded data sets.

The system may comprise a conveyor belt for conveying at least one meat piece where the conveyor belt has a transport surface where the at least one meat piece is located while determining the presence and/or position of bones in the meat piece. The system may also be a system without a conveyor belt and/or may be integrated in a measuring bow as described below. The measuring bow may be connected to a conveyor belt or may be located above a conveyor belt.

The system is based on using electromagnetic waves such as light of at least two different wavelengths where the one type of electromagnetic waves is directed from a source towards the surface of a meat piece preferably towards the upper surface and the reflected electromagnetic waves are recorded. The other type of electromagnetic waves is directed towards and into the meat piece from one side of the meat piece which preferably is not from below and the electromagnetic waves of similar type emitted from another side such as perpendicular to the side for entrance of the electromagnetic waves of the meat piece is recorded. The latter electromagnetic waves may be emitted from the upper surface of the meat piece. The two types of data sets or images registered by one or more sensors such as cameras are processed to determine presence and/or positon of at least one bone in at least one meat piece.

Meat pieces which can be examined and further handled by the system described herein may be meat pieces from any animal such as from pig, cow, cattle, deer, game, sheep, goats, poultry such as chicken. Any type of meat pieces can be examined by the system preferred is meat pieces with bones near the surfaces of the meat piece, such as meat pieces with ribs, loin with ribs, neck fillet with bones, ham with bones, fore-end or shoulder with shoulder blade. The system is especially suitable for analyzing and handling belly pieces with ribs from pork, cow/cattle, sheep, goat, deer, game etc. Bones near the surface of a meat piece is preferably located at least with a bone part within 2 cm from the meat surface, such as within 1.5 cm, e.g. within 1 cm, e.g. 0.5 cm. The bones to be loosened or removed are preferably less than 5 cm in diameter, such as less than 4 cm, e.g. less than 3 cm, such as less than 2 cm, such as less than 1,5 cm. The location in the form of depth within the meat of the bones suitable to be detected by the system and method as described herein may depend on the type of meat such as color and whether only meat is located between the bone and the meat surface or whether fat, membranes and/or tendons are also located between the bone and the meat surface. The meat between the bone and the meat surface should preferably be penetrable to at least some of the electromagnetic waves e.g. red light directed into the meat.

The at least one receiving sensor may be a first receiving sensor such as a camera recording light in the blue and/or green wavelength region and is denoted a 'blue camera'. A second receiving sensor may be a camera recording light in the red and/or infrared wavelength region and is denoted a Ved camera'. The at least one receiving sensor may be one camera capable of receiving and separating light in the blue and/or green wavelength region as well as in the red and/or infrared wavelength region. By separating is meant that data such as line scan data from some of the blue and/or green lines and from some of the red and/or infrared lines are forwarded to a programmable controller in an amount suitable to perform the analysis of the images and determine the presence and/or positon of at least one bone in a meat piece. Preferably the receiving sensor(s) perform line scanning with e.g. about 100 lines per second. Afterwards the lines are connected into images from where the presence and/or positon of at least one bone is determined.

In an embodiment the system may further comprise a first meat piece sensor for determining the presence of a meat piece being transported past a first position on the transport surface of the conveyor belt. The function of the first meat piece sensor is to initiate the sources for emitting electromagnetic waves such as lights and to initiate the receiving sensor(s) such as camera(s) to record electromagnetic waves such as lights. A communication-wise connection may be present between the first meat piece sensor and one or more of the sources for emitting electromagnetic waves and the receiving sensor(s) e.g. a single camera. The first meat piece sensor may also record the length of a meat piece passing by the sensor e.g. by using the time the meat product uses to pass by the first meat piece sensor together with the speed of the conveyor belt.

In an embodiment of the system the at least one first source for emitting

electromagnetic waves may emit light waves in the blue or green region such as light with wave lengths of between about 430-500nm or 500-565nm. This first source for emitting electromagnetic waves is denoted 'blue light source'. Light with blue

wavelengths of about 430-500nm is preferred rather than green light, as blue light gives a better contrast in the images than the green light when determining position of bones.

The blue light source is preferably positioned above a conveyor belt for transporting meat pieces to be examined. The blue light source preferably produces a blue line across the entire meat piece and perpendicular to the transport direction. The blue light source may be any light source emitting light in the blue or green regions or wavelengths, preferably LED or laser. If using a light source with multiple wavelengths a filter may be use in the blue camera. If using a blue laser no filter is need in the blue camera and the effect is higher than if a filter is used. The light should be capable of being directed into a line.

The camera recording blue light is preferably a camera suitable to perform line scanning. Preferably the camera recording blue light can perform line scanning by recording lines based on light with wavelengths only in the blue and/or green region or the camera may record light of all wavelengths being present and a filter in the camera removes all other wavelengths except the pre-determined ones in the blue and/or green region. A predetermined narrow band of wavelengths may be recorded by the blue camera. The camera recording blue light will be able to record the length and angle of bones located close to the surface of a meat piece as bones and fat are light and thus reflects the blue light. The camera recording blue light may be positioned just above (~ 0 degree) the meat piece to be examined or within 40 degree counter clock wise, which is further explained below in respect of the camera recording red light. The camera recording blue light should preferably be able to receive reflected blue light along the entire length of the bones to be examined, which may or may not correspond to the width of the meat piece being examined, such as when examining belly pieces. In an embodiment of the system the at least one second source for emitting

electromagnetic waves emits light waves in the red region including infrared (IR) region such as light with wave lengths of between about 620-1000nm. This second source for emitting electromagnetic waves is denoted Ved light source'. The red light source preferably is used for detecting the end of the bones such as the cut ends of bones in belly pieces where the ribs are cut across. The red light waves are preferably directed into the meat from one side of the meat piece perpendicular to the upper side of the meat piece and the red light will disperse within the meat, which for many animals also is red, and the light will be visible in meat parts only when observed from another side of the meat piece such as a side which is perpendicular to the side where the red right were directed into the meat. Light in the red wave region may be directed towards the meat along the entire side of the meat piece, however preferably only a small part of the meat piece is illuminated with light of red wave lengths. A camera recording red light will be able to produce images indicating areas with red light and these areas correspond to meat parts of the meat piece whereas areas without red light correspond to bone parts of the meat piece. Hereby, by registering the meat parts also the bone parts of a meat piece are registered and the presence and end position of bones are then known.

The camera recording red light is preferably a camera suitable to perform line scanning. Preferably the camera recording red light can perform line scanning by recording lines based on light with wavelengths only in the red and/or infrared region or the camera may record light of all wavelengths being present and a filter in the camera removes all other wavelengths except the pre-determined ones in the red and/or infrared region. A predetermined narrow band of wavelengths may be recorded by the red camera.

The cameras recording blue/green and red/IR light may be a single camera capable of recording light of at least blue/green and red/IR light wavelengths. The scanning system may use line scanning, area scanning or a combination of line scanning and area scanning. This may be performed for one or both of the receiving sensors or range of wave-lengths examined. For line scanning a line being one pixel in width i.e. in the transport direction of the meat piece can be examined for area scanning the area may be e.g. 20-40 pixels in width when performing the analysis. The intensity of electromagnetic waves such as light may be detected for each pixel and when detecting red light which has passed the meat piece a high intensity corresponds to light which has passed the meat where no bones is present and low intensity corresponds to an area with the presence of a bone. For blue/green light received by a receiving sensor a high light intensity corresponds to presence of bones in the uppermost part of the meat piece and low light intensity corresponds to presence of meat in the area. A threshold value of the light intensity can thus be used to determine whether a bone or meat is present in the analyzed pixel or area of pixels. The analysis of the images or data sets may be performed as an image segmentation system based on thresholding. The analysis may also include comparison of the light intensity of one pixels with surrounding pixels. For the scanning monochromatic and/or multi spectral

electromagnetic waves such as light may be used in one or more of the electromagnetic sources and the receiving sensor(s) may receive monochromatic and/or multi spectral electromagnetic waves such as light.

In an embodiment the system may further comprise a guide for guiding the second source for emitting electromagnetic waves such as a red light past the meat piece such that electromagnetic waves from the second source for emitting electromagnetic waves are directed towards the meat piece in a predetermined distance from the upper side of the meat piece when the meat piece is being transported on the conveyor belt. The red light is preferably a small light with a light emitting area of less than 2 cm ² , such as less than 1.5 cm ² , e.g. less than 1 cm ² , such as less than 0.6 cm ² , e.g. less than 0.5 cm ² , such as less than 0.4 cm ² , e.g. less than 0.3 cm ² , such as less than 0.2 cm ² , e.g. less than 0.1 cm ² . Preferably the light emitted from the red light source will illuminate a spot of about 2-3 cm in diameter and penetrate into the meat. The red light source may be any suitable red light source such as a LED or laser, e.g. a powerful single red LED or laser, and the light source may emit light with wavelengths selected from the red, near infra-red (NIR) or infra-red (IR) regions.

The guide may comprise a holder for the red light source which holds the red light source such that light waves from this light source is directed towards and into the meat piece. The red light source may be with a small lighting area such as a lighting area of less than 2 cm ² . The guide may further comprise a kind of ski or slider which can be positioned onto e.g. the upper surface of the meat piece and slide along the meat when the meat piece is conveyed by the transport belt. Preferably the ski or slider possesses a minimal pressure upon the meat piece by only sliding along the meat piece such that the obtained information corresponds to the position of the bones when the slider is no longer on top of the meat piece. The ski or slider may be of any suitable material which may be in contact with meat during a meat processing process. The ski or slider may be about 4-6 cm long, 1-2 cm wide, and 0.5-5 mm thick. The guide may further comprise a spacer located between the slider and the holder for holding the red light source and which may keep a firm distance between the slider and the red light source. The spacer may be adjustable such that the distance between the red light source and the slider can be adjusted such as according to the type and size of meat pieces to be examined. The ski or slider will preferably be located on the top surface of the meat piece being conveyed and will slide along the upper surface of the meat piece and follow the contour of this side, hereby the red light source in the holder will be positioned in a predetermined distance from the upper surface of the meat piece. The pre-determined distance should preferably be selected such that red light waves emitted from the red light source are directed towards the side of the meat piece e.g. beneath or beneath and onto the location of bone ends e.g. cut bone ends or preferably such that no red light waves are directed in a direction above the upper surface of the meat piece. Securing that substantially all red light waves enter into the meat piece improves the contrast of the obtained images when determining the position of the bone ends close to the side of the meat piece where the red light waves enter into the meat piece. The use of a red light source with a small lighting area results in illumination of only a small part of the meat piece conveyed on the conveyor belt, this gives a better lighting of the meat than if the entire side of the meat is illuminated. Preferably the red light is not in direct contact with the meat, but located as close to the meat piece as possible, preferable in a distance of less than 1 cm.

The camera recording red light may be positioned to record light with red wavelengths of similar wavelengths as is used in the red light directed towards the meat, and may be selected from the red, NIR or IR regions of wave lengths. The camera recording red light records light which has passed through the meat and need only register red light in an area of the meat close to the position where the red light source directs red light into the meat piece. Such an area may include the cut ends of bones (this position can be denoted 0 cm) and extend e.g. 5-15 cm along the bones in the meat. For a belly piece with cut ribs the camera recording red light may record light from the first 5-10 cm calculated from the location of the cut rib ends. The camera recording red light may be positioned directly above the area from where it register light or be angled such that the camera is further away from the red light source than if located just above the area from where it register light. If the red light source is positioned at about 90 degree clock wise of a meat piece (the upper part of the meat piece located on a conveyor belt is 0 degree when measured from above) then the camera recording the red light may be positioned between 0-40 degree counter clock wise (ccw) such as 10-35 degree ccw e.g. 20-30 degree ccw. The first source for emitting electromagnetic waves such as a blue light source and the first and second receiving sensor such as a blue camera and a red camera may be arranged in a measuring bow suitable to be located above a conveyor belt. The blue and red camera may be only one camera. The cameras are facing downwards and are preferably run in a line scan mode with each line being substantially orthogonal to the transport direction. Area scan or line scan combined with area scan may also be used in the recording of data from the illuminated meat piece. The second source for emitting electromagnetic waves such as a red light source is preferably located close to the conveyor belt as described elsewhere herein. Meat pieces to be analysed can be conveyed by the conveyor belt and underneath the measuring bow, the distance between the conveyor belt and the measuring bow should be such that electromagnetic waves can be directed towards the meat piece and received from the meat piece. The measuring bow may also comprise the processing unit such as a PLC (programmable logic controller). The sources for emitting electromagnetic waves and the receiving sensors may all connected by wires or wireless to the processing unit/PLC. The PLC may control the sources for emitting electromagnetic waves and the receiving sensors such as in respect of wavelengths to be emitted and recorded. The PLC may also be connected by wires or wireless to a handling system such as a robot handling system to forward results based on the analysed images or datasets to the handling system. The PLC may further be connected by wires or wireless to the first meat sensor.

The measuring bow may further comprise a user interface, by which a user may inform the processing unit of data related to at least one meat piece to be examine, such as type of meat piece, type of bones to examine, data relating to the animal type or race from where the meat piece is obtained, type of analysis to be performed and/or type of process to be performed after the analysis is performed.

The cameras to record red and blue light may be two cameras and may be located in a staggered arrangement when compared to the transport direction of meat pieces.

Transversely to the transport direction the cameras may also be staggered and each of the cameras may be positioned to obtain optimal images of the meat piece being examined. Also along the direction of the transport direction the cameras may be staggered such as between 10 and 50 mm.

In an embodiment of the system the first meat piece sensor may be connected to the at least one receiving sensor such as a camera and optionally also to the at least one first source for emitting electromagnetic waves and/or to the at least one second source for emitting electromagnetic waves such that when a meat piece passes the first meat piece sensor information is forwarded to the at least one receiving sensor initiating the function of the receiving sensors and optionally initiating the function of the sources for emitting electromagnetic waves. The connection may be wireless. As soon as a meat piece conveyed by the conveyor belt is registered by the first meat piece sensor this sensor may transmit a signal to the blue and red light source, and the blue and red camera (which together may be a single camera), which are then activated to emit light waves and record light waves. When the meat piece has passed the first meat piece sensor a signal can be transmitted at least to the blue and red camera (which together may be a single camera), however, the light sources and camera(s) should preferably not stop lighting and recording before the entire meat piece has been examined, a predetermined time span may thus be determined before the camera(s) and optionally the light sources end recording and lighting, respectively. Such a time span may be calculated due to the speed of the conveyor belt conveying the meat piece, and may be between e.g. 0.1 sec to e.g. 5 sec, preferably between 0.2 sec to 3 sec, more preferably between 0.3 to 2 sec, even more preferably between 0.1-1 sec or 0.1-1.5 sec.

The first meat piece sensor may be any kind of sensor capable of detecting the presence of a meat piece on a running conveyor belt. The first meat piece sensor may comprise a light beam e.g. positioned across the transport surface of the conveyor belt and when this light beam is interrupted it corresponds to the presence of a meat piece positioned on the conveyor belt. When the light beam in no longer interrupted this is interpreted such that the meat piece has passed the first meat piece sensor.

In an embodiment the system may further comprise a second meat piece sensor for determining the presence of a meat piece being conveyed past a second position on the transport surface of the conveyor belt, wherein the first meat piece sensor may be located upstream of the second meat piece sensor according to the transport direction of meat pieces being conveyed on the conveyor belt and the second meat piece sensor may send information to an equipment such as a robot handling the meat piece.

The second meat piece sensor is preferably located along the conveyor belt at a position where the meat piece has passed the light sources and cameras for recording data used for determining presence and location of bones, and this recording of data has been performed. The second meat piece sensor may register the presence of a meat piece on the conveyor belt in the same way as the first meat piece sensor does. The second meat piece sensor may initiate a working tool such as a robot in a working zone along the conveyor belt. The second meat piece sensor may be located before or after such a working zone and may transmit information to a working tool such as a robot. The robot may operate a handling tool suitable to handle the meat piece, such a handling tool may be a bone removing tool e.g. a rib removing tool. The conveyor belt may be stopped when the second meat piece sensor register the presence of a meat piece and then the working tool such as a robot may handle the meat piece such as removing bones e.g. ribs. When the robot has ended its handling of the meat piece the conveyor belt may restart and convey the meat piece away from the handling zone. More preferably the handling of the meat piece is performed while the conveyor belt is running, hereby the second meat piece sensor transmits a signal to a robot when this sensor register the presence of a meat piece, the robot receives processed information such as of the positon, length and orientation of bones in the meat piece and the robot handles the meat piece such as loosen or removes the bones e.g. ribs.

A meat piece analyzed by the scanning system is preferably conveyed without being twisted or turned around, hereby the activation of the second meat piece sensor can be use as information to the processing unit or robot of the position of the meat piece whereby the processing unit or the robot can calculate - based on information received from the scanning system - where to loosen bones present in the meat piece. Hereby no further system need to be used to determine the location of the meat piece.

An optical or ultrasonic height sensor may also be a part of the system such as integrated into a measuring bow. The height sensor is preferably facing downwards and being capable of measuring the height contour of the meat when a meat piece is transported under the height sensor. The height sensor can also be connected to the PLC by wires or wireless.

An optional encoder or resolver may also be a part of the system for measuring the conveyor speed and may be integrated into a measuring bow. The encoder or resolver may be connected to the PLC by wires or wireless. Alternatively, the conveyor speed can be measured once and configured as a parameter in the system.

The measuring system is described herein in combination with analyzing meat pieces which are conveyed such as by a conveyor belt. For situations where the meat pieces are not conveyed the measuring system may be the moving part. A measure bow may be moved above a non-moving meat piece and obtain data and perform the analysis as described herein. For such a system a measuring bow may comprise a moving system for moving the measure bow past the meat piece, the moving system may be located above the measure bow or along the area where the meat piece to be analysed is located. Such moving systems for moving a bow are known by the skilled person.

Another aspect of the invention relates to a method for determining the presence and/or positon of at least one bone in at least one meat piece while the meat piece is conveyed such as on a conveyer belt and where the method optionally further is for determining the length and/or orientation of the at least one bone, the method may comprise the steps of a. conveying at least one meat piece on a transport surface such as on a conveyor belt,

b. directing electromagnetic waves towards a first surface of the at least one meat piece,

c. directing electromagnetic waves towards a second surface of the at least one meat piece, where this second surface preferably is a surface not in contact with the transport surface,

d. receiving electromagnetic waves of at least one pre-determined wave range and which are reflected from the first surface

e. receiving electromagnetic waves of at least another pre-determined wave range and which are transmitted through the meat piece and emitted from the first surface of the meat piece and/or receiving electromagnetic waves of the at least another pre-determined wave range and which are emitted from a third surface of the meat piece, and

f. processing the received electromagnetic waves to construct at least two images or datasets which may be superposed over each other such that one image or dataset is constructed which indicate the presence and/or position of at least one bone in the meat piece.

Preferably the at least two images or data sets are constructed based on information received from both the pre-determined wave ranges such that at least one image or data set is constructed based on each pre-determined wave range. In an embodiment of the method may comprise one or more features selected from the group of:

• the electromagnetic waves directed towards a first surface of the at least one meat piece comprises at least light in the blue or green wave region such as light with wave lengths of between about 430-500nm or 500-565nm and

· the electromagnetic waves directed towards a second surface of the at least one meat piece comprises at least light in the red region including infrared region such as light with wave lengths of between about 620-1000nm, and

• receiving light in the blue or green wave region which light is reflected from the first surface of the meat piece,

· receiving light in the red or infrared wave region which light is emitted from the first surface or from the third surface of the meat piece, • processing the received light into at least two images or dataset and adding and/or subtracting data from the at least two image or dataset to indicate the presence and/or position of at least one bone in the meat piece.

The method can be further understood from the description of the function of the system as well as from the example, from where features can be combined with the description of the method.

A further aspect of the invention relates to use of the system as described herein for determining the presence and/or positon of at least one bone in at least one meat piece. The use may be performed by the method as described herein. The use is preferably for determining the presence and/or positon of at least one rib in a belly piece but although described in respect of ribs should be understood as being suitable to determine the presence and/or position of other types of bones being located near the edge of a meat piece.

The measuring system as described herein above may be used for determining the presence and/or positon of at least one rib in a belly piece and loosening the ribs, such a system may be automatic and may comprise two individual subsystems located close to each other such as both located on the same conveyor belt, the subsystems may be:

1. A measuring system, designed to determining the presence and/or positon and measure angle and length of each rib on a belly piece from e.g. a pig carcass, 2. An industrial robot with a custom tool, such as a tool made specific for loosening of a rib on a belly piece.

In such a system the conveyor belt conveys the product first through the measuring system and then to the industrial robot. It is assumed that the product is not deformed during the transport between the two subsystems. The measuring system calculates coordinates as X and Y of the positions (length and width) of the bones based on the input from the cameras and the Z position (the height) from the height sensor. The calculations may include at least a start position of one or more bones present in the meat piece, an end position of the bones and the height within the meat piece of the start and end position of the bones resulting in determination of position, angle and length of bones within a meat piece. This information is communicated to an industrial robot capable of integrating the positions into an algorithm describing the working pattern of a tool mounted on the robot arm, and hereby a working pattern applicable for the meat piece to be handled is calculated. Based on the calculated working pattern the robot may handle the meat piece such as loosening or removing the bones from the meat piece. The two subsystems are preferably connected communication wise through a form of physical and virtual protocol, e.g. TCP/IP on Ethernet, Canbus, Profibus, etc. The protocol is able to transport the measurements or processed data obtained in the measuring system from the measuring system to the robot. A system for loosening or removing bones is further described below and may be a part of the system with the two subsystems i.e. measuring system and industrial robot.

Another aspect of the invention relates to a calibration tool for calibrating the data obtained in the measuring system making it possible for the measuring system to locate the ribs in robot-space, such a calibration system may comprise the following : · Calibration tool which in outer dimensions resembles the same area as the ribs of a meat product, and where

• the calibration tool has at least three fix points, located in the perimeter of the calibration tool, which can be located both optically by the measuring system, and tactile or near tactile by the robot, and

· the height of the calibration tool can be altered to represent the thinnest and thickest product and those in between.

The dimensions of the calibration tool may be altered to resemble the area or the bones in a meat piece which should be analyzed for determining the presence and/or positon of bones. The calibration process can be described as:

• The calibration tool is placed on the conveyor belt similar to a meat product when this meat product should be processed in the system described herein.

• When the calibration tool reaches the measuring system, it is scanned as a

normal meat product, however the detection phase is different, in that it detects the at least three fix points.

• When the calibration tool reaches the second meat piece sensor located after the area of performing the scanning and in the robotics system, the conveyor belt stops.

• The robot is manually jogged to each fix point of the calibration tool, so that the tool on the robot arm is placed relative to each point the same way it would be placed at a bone such as at a rib.

• The position (X, Y, Z) of each fix point is read (manually or automatically) from the robot and inserted to the corresponding point found by the measuring system (manually or automatically). • The measuring system now has at least a three-point calibration which correlates image positions to robot positions, relative to the first and second meat piece sensors.

The custom tool may be a robot tool in the form of a rib puller for an industrial robot, such a robot tool may comprise

• at least one counter hold for supporting the tool towards the meat piece such as towards the belly piece at an area which is with or close to non-exposed ends of the bones such as ribs or in at least one area beside a bone to be loosened, and

• at least one movable pull bar which may be a longitudinal movable pull bar, and · at least one string for loosening a bone such as a rib when being pulled along the bone, where the string is fastened to the pull bar for pulling the string in a direction towards the at least one counter hold and optionally past the at least one counter hold, and

• at least one longitudinal holding-down bar for holding down at least one bone such as a rib while loosening this bone, where said holding-down bar is substantially parallel to said pull bar and has a length corresponding at least to the length of said pull bar and

• a connecting part for connecting the tool to an industrial robot.

The tool as described is preferably a rib puller but may also be suitable to loosening or remove other types of bones from slaughtered animals. Preferably a slaughtered animal is cut into smaller pieces before loosening and optionally removing at least one bone with the tool as described herein. Most preferably the rib puller is used to loosen at least one rib from a belly piece where the rib end are being exposed when a cut is performed substantially parallel to the spinal column hereby the cut ends of ribs have an angle of about 25 ^° at least when cutting belly pieces of pigs.

The term belly piece should be understood to comprise any size of a meat piece originate from the belly part of a slaughtered animal and comprising at least one rib. In most situations such as at slaughterhouses a belly piece comprises at least two ribs such as at least five ribs, such as at least ten ribs, such as all the ribs of half a carcass. As an example a pig belly piece may include all the ribs of one side of the pig and the belly piece can be e.g. 60-70 cm long and 20-30 cm wide, though the dimensions are dependent on the size of the pig, and where the width is determined by a cut along the spinal column and a second cut through the ribs, and which cut is substantially parallel to the spinal column. The number of ribs which should be loosened or removed from a pig belly piece may be e.g. 10-12 such as 11, and which may be of a length between about 1.5 cm and about 20 cm when the pig belly piece is cut as described just above.

The counter hold may comprise a non-movable support or a movable support which is movable in a direction (e.g. along the Y-axis) substantially perpendicular to the working direction of the pull bar (e.g. along the X-axis) and such that the meat piece has it spinal column in the third direction (e.g. along the Z-axis). When the tool is used for loosening ribs the counter hold can be located close to the spinal column of the belly piece to hold and support the meat piece securing the meat piece does not move substantially while at least one rib is loosened by the at least one string of the tool. The counter hold may also be a plate and/or comprises at least one vertically movable rod or element. The counter hold may also be at least one plate with pins which is positioned on the top part of the meat piece when a bone should be loosened from the meat piece.

A movable support of the counter hold may comprise different elements being

individually movable e.g. as indicated in the figures with movable rods, hereby the counter hold may adjust to the shape of the meat piece which should be supported and thus increase the strength of the support. The individually movable elements of a movable support also make it easier for a robot such as an industrial robot to use the tool as it is not requested that the entire counter hold is positioned in a specific position in respect of the spinal column, as the elements adjust to the shape of the meat piece. The pull bar comprises string mounting tools to attach a string to the pull bar. Such mounting tools are known in the art.

The holding-down bar which is for holding down at least one bone such as at least one rib while loosening this bone should be strong enough to hold down any bone which lift itself upward as the string is pulled along this bone and loosening it from the meat. It may be important to hold down the bones to be loosened or removed to avoid the bone lift itself from the meat or the bone breaks. Especially ribs which are porous in structure may easily break, which should preferably not happen as this may interrupt or prolong the process of loosening the ribs in a belly piece. The holding-down bar may be longer than the pull bar when the tool is in a strat position as illustrated in Fig 5, as in this position the string is positioned under a bone end such as a rib end and this bone will secure the string stays under the holding-down bar when the pull bar is activated. The holding-down bar may have any suitable form when observed in a transverse cut of the bar, such as circular, oval, U-shaped e.g. inverted U-shaped, squared or rectangular. The holding-down bar may also be a loading means such as a loading means of a robot tool. The loading means may be capable of holding down a bone to be loosened during the process of pulling a string along the bone. The tool may further comprise at least one loading means each located at one end of the holding-down bar and such that the string connected to the pull bar at least partly can surround the loading means when the tool is not in use and where the loading means is for securing feeding of the string around an exposed bone such as an exposed rib before loosening this bone.

The loading means may have a cavity suitable to be positioned around an exposed bone before loosening the bone, hereby the loading means may be fully or partly hollow securing an exposed bone end can enter into the cavity, and at the same time secure the strength of the loading means. The loading means may have a sharp edge along an entrance to the cavity such that when the loading means is loaded on an exposed bone end the sharp edge of the loading means cut into the meat and/or membranes beneath the bone such as a rib securing a proper loading onto the bone end and thus securing the proper location of the string when being pulled by the pull bar and thus the string will be directed along and beneath the bone hereby loosening the bone. For a robot tool the cavity may be present all the time or may only be present from the time where the loading means is positioned such that it encircles a cut end of a bone such as of a rib, this may be performed by activating the holding-down bar and pushing it a little along a rib to be loosened. The cavity may be about 0.5-2.5 cm deep, such as 1-2 cm deep, e.g. 1-1.5 cm deep. A cavity of a loading means may also be present when a cleaning plug is retracted or the loading means is moved slightly forward in front of a cleaning plug prior to positioning the loading means in front of an exposed bone end.

The tool as described herein may be connected to a motor capable of being activated for pulling or pushing the pull bar from a start position to an end position and hereby pulling the string along a bone such as a rib. The motor may be an electric motor or a pneumatic system.

The tool is preferably made of a strong material acknowledged to be used for handling food. Preferably at least the counter hold, the pull bar, the holding-down bar, and the loading means are made of a metal, such as steel such as stainless steel. The string is preferably made of a strong and flexible material e.g. nylon. The tool may comprise at least two parallel sets of pull bars each including a string and holding-down bars, such as two or three sets, and each set comprises features as described herein. Hereby at least two, such as e.g. two or three bones or ribs may be loosened at a time. Such a tool with multiple sets of pull bars and holding-down bars may be connected to a robot as described elsewhere herein. The tool as described herein may be a tool such as a rib puller suitable to be mounted on an industrial robot which can manage the rib puller to pull at least one rib from a meat piece such as from a belly piece.

The dimensions of the tool such as length of pull bar and/or holding-down bar and/or length and inner diameter of the loading means may be determined in respect of the type of bones such as ribs which should be loosened, as well as in respect to the animal race and age i.e. size of the animal, and thus to the size of the bones in the carcass.

In the robot tool the pull bar is pushed by a motor such as a pneumatic system, but the function is to pull the string along a bone. Part of the robot tool e.g. the pull bar and the loading means on the holding-down bar may be mirrored such that the pull bar is pulled instead of dragged when in function.

The system pushing or pulling the pull bar may be a servo motor making it possible to control the speed of the string being pulled beneath a bone such as being pulled slower at the beginning than at the end of the pull.

As described the holding-down bar in the robot tool is movable such that it can be pushed forward to encircle the loading means around the end of the cut end of a rib. When the holding-down bar is in a start position there need not be a cavity in the loading means, as the holding-down bar is moveable. The moving of the holding-down bar forward and backward such that the cavity is eliminated between loosening two ribs, secure substantially no meat leftovers is located in the cavity.

The counter hold for the robot tool may be in the form of a plate with pins. The number of these plates may be any suitable to secure the meat piece is kept in position securing the bones can be loosened by the tool, preferably at least one plate is positioned on each side of the holding-down bar. The number and position of the pins on the plates should be such that the meat piece is kept in a firm grip and is preferably not moving during loosening of a rib. The length of pins is preferably 2-3 mm and the number of pins is preferably at least 25 at each plate, such as between 30 and 70, such as about 50. The level of the tips of the pins may be equal for all the pins such that the pins are fixed, however the pins may also be attached to the plate such that the pins are adaptive and adapt to the belly piece such that pins enter more into meat of the belly than into bone. The counter hold when holding the meat in the area on each side of a rib to be loosened may further have the function of securing the meat bridges or muscle bridges located between the ribs such that these are not removed from the belly piece when ribs are pulled. The robot tool may further comprise a piston to move the tool away from the

attachment device, piston guides and a locking plate for shaft securing the tool may stay in the position where the tool is pushed away from the attachment device. Pushing the tool towards the belly piece just about 1 cm secure the holding-down bar is close to a rib to be loosened. The counter hold may be activated by at least one piston pressing the counter hold towards the belly piece.

The robot tool as illustrated in fig. 4-6 is working from the side of a belly piece where the ribs have the cut ends. The robot handles the robot tool based on the information received from a measuring system such as a measuring system described herein. An aspect of the invention may relate to an automatic system for loosening at least one bone from a meat piece such as at least one rib from a belly piece of a slaughtered animal, such an automatic bone loosening and/or bone removing system may comprise

• At least one scanner such as a measuring system for obtaining scanning

information when scanning at least one meat piece to localize the presence and/or location and/or size of any bones such as ribs being located close to the surface of each of the at least one meat piece,

• A robot tool comprising a device as described herein for loosening bones from a meat piece such as ribs from a belly piece of a slaughtered animal where the device further comprises robot connecting means such that the device constitute a robot tool,

• A robot, such as an industrial robot with at least one working arm suitable for connecting the robot tool to the robot arm and suitable for managing the robot tool in a process for loosening bones from a meat piece such as ribs from a belly piece of a slaughtered animal,

· At least one processor for processing the scanning information in respect of each of the scanned meat pieces and for computing working paths for the robot arm including the robot tool,

• A robot arm controller for managing the robot arm based on working paths

information received from the processor,

· Optionally a conveyor belt for conveying at least one meat piece.

The robot may be an industrial robot which is automatically controlled, reprogrammable, and has a multipurpose manipulator programmable in three or more axes.

When in function the robot may perform all the work of loosening ribs from a belly piece, or one or two ribs may be removed manually before the robot removes or loosen the remaining numbers or a predetermined number of the ribs from the belly piece. An abattoir worker may remove one or two ribs manually and simultaneously loosen and remove the pleura covering the belly piece above the ribs and afterwards the robot loosen or remove the remaining numbers or a predetermined number of ribs e.g. by loosening 1, 2 or 3 ribs at a time. An abattoir worker may also remove only odd bones and the pleura before the robot loosen the remaining ribs.

The robot may be capable of loosening or removing at least one rib such as in total 3-14 ribs from each belly piece from at least 300-550 belly pieces per hour.

A method for loosening at least one bone from a meat piece such as at least one rib from a belly piece of a slaughtered animal where at least one end of the bones are exposed may comprise the steps of:

• Scanning the meat piece with a measuring system as described herein,

• processing the obtained data to determine presence and position of at least one rib where this processing also includes determining a robot working path,

• placing a tool as described herein with at least one holding-down bar above and substantially parallel with at least one bone which is to be removed and with the at least one string in front of the exposed bone end(s),

• activating the pull bar(s) whereby the string(s) is/are pulled by the pull bar(s) towards the counter hold and

• hereby loosening or releasing the at least one bone at least along part of the longitudinal direction of the bone.

The method may comprise loosening or removing one or more ribs at a time, such as one, two, three or four ribs at a time. Preferably a robot can loosen one, two or three ribs at a time.

In an aspect the invention also relates to use of the measuring system and robot tool described herein for loosening or removing at least one bone from a meat piece such as at least one rib from a belly piece of a slaughtered animal where at least one end of the bones are exposed.

When loosening bones such as ribs with the robot tool the string may be pulled along the bone to a certain point, which may be determined by the measuring system. Such a certain point may for ribs be until the feather bone. As the ribs are not of equal length the location of the feather bone may be determine for each rib to be removed.

A rib puller for an industrial robot is illustrated in Fig. 5-7. Before this rib puller is activated to remove ribs from a belly piece, the membrane (pleura) located above the ribs is removed and the belly piece is analysed such as be a measuring system as described herein. This rib puller when in function can be described by performing the following steps after it has received the working paths from the measuring system at least for the first rib to be loosened and subsequent for the following ribs to be loosened :

1. The rib puller is in a waiting position where the pull bar with the string is drawn back with the pull bar within the motor such as a pneumatic system, the counter hold is located in a position above the holding-down bar and the attachment device for connecting the tool to an industrial robot is in a withdrawn position. The tool in a waiting position or start position is shown in Fig. 5.

2. When the rib puller is located above a rib in a belly piece the contact with the belly piece is established by activating the pistons located close to the attachment device such that the tool is pushed towards the belly piece.

3. The belly piece is maintained in position by activation the pistons pushing down the counter hold such that the pins make a firm connection with the belly piece.

4. The loading means is loaded onto an end of a rib. The holding-down bar with the loading means is moveable such that when the holding-down bar is in position the holding-down bar with the loading means is moved forward and the loading means encircles the cut end of a rib bone herby securing the string will be pulled along the rib to be loosened.

5. The motor activates the pull bar and the string is pulled along the rib until it

reaches the feather bone or just before it reaches the feather bone and hereby loosening the rib.

6. The tool returns to the start position by doing the steps in reverse order:

deactivating the pull bar, returning the loading means, de-activating the pistons controlling the counter hold, deactivating the pistons located close to the attachment device and hereby lifting the entire tool a few centimeters above the belly piece.

7. Moving the tool to another rib to be loosened and place the holding-down bar at an angle similar to the rib to be loosened and then repeating the steps 2-6.

8. The process steps are repeated until all the ribs or a pre-determined number of ribs in a belly piece are loosened.

The process with the robot tool may be performed on non-moving meat pieces or meat pieces being conveyed by a conveyor belt. The speed of a conveyor belt may be e.g. between 50-100 mm/sec, such as about 50 mm/sec.

Detailed description of the figures

Fig. 1 is a schematic illustration with a top view of a measuring or scanning system and a working zone. A conveyor belt (14) conveys a meat piece (22). The meat piece (22) is shown at a position where the measuring or scanning has been finished and the meat piece (22) is under transport to a working zone (21). The running direction of the conveyor belt (14) is indicated by the arrow and the meat piece is conveyed from left to right on the conveyor belt (14) and when the meat piece starts to pass the first meat piece sensor (15) the measuring system starts lighting and recording lighting. The measuring system comprises red light (19), red camera (17), blue light (e.g. located beneath the blue camera) and blue camera (18). The measuring system stops lighting and recording lighting at a pre-determined time after the meat piece (22) has fully passed the first meat piece sensor (15). The recorded data is processed by a processor (not shown) and the information can be sent to an automatic device such as an industrial robot (not shown) handling the meat piece in the working zone (21). An industrial robot may be activated when the second meat piece sensor (16) records the presence of the meat piece in the working zone (21).

Fig. 2 is a schematic illustration with a side view of a measuring system and a working zone. The system is the same system as illustrated in Fig. 1. In this illustration it is shown how the blue light (20) can be located beneath the blue camera (18) and the red light (19) is located just above the conveyor belt (14). The first meat piece sensor (15) and the second meat piece sensor (16) are located just above the conveyor belt (14).

Fig. 3 is a schematic illustration with a transversal view of a measuring system. The system is the same system as illustrated in Fig. 1 and Fig 2. In this illustration it is shown how the blue light source (20) can be located beneath the blue camera (18) and the red light source (19) is located just above the conveyor belt (14) with the light being directed towards the meat piece (22) and the red camera (17) can be located away from the red light source (19) and angled to record red light from the meat piece (22). The exact location of the light sources and cameras are not illustrated. The red camera (17) should preferably be able to record red light from the area of the cut ribs of the meat piece (22).

Fig. 4 illustrates the principle of locating a string around the cut end of a bone such as a cut end of a rib in a belly piece. The figure illustrates a handheld, pneumatic rib puller located in a start position above a belly meat piece. The rib puller comprises a holding means (1) for holding or supporting the belly meat piece during the process of loosening or removing a rib, a movable pull bar (2) with a string (3) at the end, a holding-down bar (4), loading means (5), a first handle (6) and a pneumatic system (7). The loading means (5) is hollow at least in the part facing the string (3) and the hollow part has a size in the form of an opening area and length suitable to place the loading means (5) around the tip of an exposed rib (9). The rim of the loading means (5) in the part facing the string (3) may be sharp e.g. sharp as a knife, making it possible for it to cut into the belly meat when the loading means (5) is loaded on the tip of an exposed rib (9). When the rib puller is in function the string (3) and the loading means (5) are initially positioned around the tip of an exposed rib (9), then the pull bar (2) is draw towards the holding means (1) by activating the pneumatic system (7) and the string (3) while being dragged towards the holding means (1) will loosen the rib from the belly meat (8). The holding-down bar (4) will secure the rib (9) is not lifted too much from the belly meat and/or is not cracking. The holding means (1) for holding the belly meat (8) while loosening or removing a rib (9) is illustrated with moveable elements on each side of the rib puller. These elements will adapt to the physical shape of the meat piece. Illustrated is exposed end of ribs (9) and a loading means (5) positioned right in front of a rib end.

Fig. 5 illustrates a rib puller for an industrial robot, where the rib puller is in the start position. The rib puller comprises a holding means (1) for holding or supporting the belly meat piece during the process of loosening a rib. The holding means (1) is shown in the form of two plates with pins where the plates are located on each side of a holding-down bar (4). The holding means (1) are activated by a piston (24, Fig. 5) which pushes and holds the plates towards the meat. In this figure the piston are de-activated and the plates are in a non-holding position. The rib puller also comprises a movable pull bar (2) with a string (3) at the end, a holding-down bar (4), loading means (5), a motor such as a pneumatic system (7), an attachment device (10) for connecting the tool to an industrial robot, a piston (11) to move the tool away from the attachment device (10), piston guides (12) and a locking plate for shaft (13) securing the tool may stay in the position where the tool is pushed away from the attachment device (10). The loading means (5) is hollow forming a cavity when the holding-down bar (4) is moved in front of a cleaning plug (23) such that the loading means (5) encircles the rib end. The rim of the lower part of the loading means (5) may be sharp e.g. sharp as a knife, making it easy for it to cut into the belly meat when the loading means (5) is loaded on the tip of an exposed rib. When the rib puller is in function the string (3) and the loading means (5) are initially positioned around the tip of an exposed rib, then the pull bar (2) is pushed towards the holding means (1) by activating the motor such as a pneumatic system (7) and the end of the pull bar (2) with the string (3) continues pass the holding means (1) such that the string (3) while being dragged by the pull bar (2) will loosen the rib from the belly meat.

Fig. 6 and 7 illustrate a rib puller for an industrial robot, where the rib puller is in the end position where the pull bar (2) is pushed along the holding down bar (4). The function of the tool is described further in respect of Fig. 4. Fig 6 also shows how the holding means (1) are activated when a piston (24) has pushed the holding means (1) downward. Fig. 7 illustrates especially the holding means (1) with the pins and the cavity of the loading means (5) when the holding-down bar (4) is activated. The attachment device (10) for connecting the tool to an industrial robot is connected to a piston system which when activated pushes the entire tool away from the attachment device (10) and in this position a locking plate for shaft (13) secure the tool will stay in this position during loosening a rib.

Fig. 8 is a schematic illustration of a belly piece with ribs where the skin is facing downward. Variation exists between animals due to e.g. distance between ribs, angling of ribs etc. The figure illustrates a pig belly piece (8) as it may be cut at an abattoir and thus illustrates ribs (9) of one individual animal. The dotted lines illustrate the contour of a cut belly piece (8). The belly piece (8) is cut with a total of 13 ribs (9) 11 of the ribs (9) have cut ends along the top line of the belly piece (8) and 2 odd ribs are cut differently when the right line of the belly piece was cut. The figure illustrates the different lengths of ribs (9) and the position of ribs (9) and hereby showing that different distances between ribs (9) occur. From the illustration different angling of the ribs (9) also appears. The distances between two adjacent ribs may be e.g. 30-50 mm in pork meat such as in pork meat obtained from pigs with a slaughter weight of about 60-110 kg. The angle of the ribs may be between 10-60° in respect of the cut exposing the cut bone ends. Fig. 9 illustrates directing light towards one side of a meat piece and receiving light waves which has passed the meat piece. A belly meat piece (8) with a rib (9) close to the upper surface of the meat piece (8) is conveyed on a conveyor belt (14). A ski (26) is located on the top of the meat piece (8) and is connected to a guide (25) which is also connected to a red light source (19) and the guide (25) secures the red light source (19) is directed towards the meat piece (8) in a certain distance from the top part of the meat piece (8). Light waves (27) are emitted from the red light source (19) and into the meat piece (8) where some light waves will pass the meat and be directed towards the camera for recording red light (17). Light waves (27) are only shown to illustrate the operating principle of the system. Red light waves (27) will not pass through a rib (9) and the meat piece (8) need not perform a refraction of the light waves as indicated.

Example

This example describes a setup of a measuring system as used for measuring the presence and position of ribs in pork chest pieces (belly pieces). The example further describes automatic removal of ribs from such pork belly pieces where the information obtained by the measuring system was processed and forwarded to a robot which removed the ribs from the belly piece. Loosening of single ribs

The system consisted of two individual subsystems, both located on the same conveyor belt:

1. A measuring system, designed to locate and measure angle and length of each rib on a chest piece from a pig carcass, the system is illustrated in Fig. 1-3,

2. An industrial robot with a custom tool as illustrated in Fig 5-7, made specific for loosening of a rib on the chest piece.

The conveyor belt conveyed the product (chest piece) first through the measuring system and then to the robot. The orientation of the products was such that the cut between the chest and the loin faced right in the transport direction i.e. with the cut ends of the ribs at the right side of the product determined according to the transport direction of the belly pieces. It is possible, without loss of generality, to mirror the system, so the cut faces the left side.

The two subsystems were connected communication wise.

Measuring system

The measuring system for determining the presence and position of ribs comprised the following :

1. A camera facing downwards, centered around the center of the product (the belly piece). The camera was run in a line scan mode, with each line being orthogonal to the transport direction. This camera was designated "the blue camera" and recorded light with blue wave lengths.

2. Blue light (LED), centered at the above camera's scan line and directed towards the rib part of the belly pieces such that the ribs were illuminated in the entire length.

3. A camera placed to the left (determined according to the transport direction of the belly pieces) of the blue camera, looking downwards in -30 degree angle (= 30 degree counter clock wise). The camera was run in line scan mode, as with the blue camera. This camera is designated "the red camera" and recorded light with red wave lengths.

4. A powerful single red laser, placed horizontally on the right side (determined according to the transport direction of the belly pieces) of the product, lighting up the product just below the ends of the rib bones. The light was mounted on a ski (fixing ski) that was able to follow the contours of the ribs in such a way that the light was always just below the bones, independent of the height of the product and curvature of the bones.

5. An optical sensor (first meat piece sensor) placed a few centimeters before the scan lines of the cameras. The purpose of this sensor was to start and end the scanning of a product, and also to measure the length of the belly piece.

6. An optical or ultrasonic height sensor, facing downwards. The sensor measured the height contour of the meat.

The measuring process was as follows:

• The product (belly piece) was transported on the conveyor belt and reached the first meat piece sensor, which initiated the scanning of the red and blue cameras, and the height sensor.

• After the rear end of the product had left the first meat piece sensor and thus the scanning zone, the scanning stopped.

• The line scans from each of the two cameras were stitched together to form two images. These images were analysed, and the end of each rib, along with the length and angle were detected. The X, Y of the position (length and width) were calculated using the cameras, and the Z (the height) was calculated using the height sensor.

• The measurements, position, angle and length of each rib were communicated to the robot before the first rib was loosened.

Detection method

The red camera was used for detecting the start position (the cut end) of each rib, the blue camera was used for detecting the length and angle of each rib.

Red camera The red light easily penetrates the meat of the product, but not the bones. When line scanning the product while scanning from above and illuminating the side, the contour of the bones are detected as dark areas, whereas the area between the bones is clearly lit. The setup can be varied by switching position of camera and light source, the key point is that they are positioned roughly perpendicular to one another. Blue camera

The blue camera takes advantage of the fact that bone and fat are white and therefore reflects a lot of the blue light, while meat does not. Using blue light, the image from the blue camera have a high contrast between the bones and the meat between the bones. Optionally using the points located by the red camera, each rib bone is tracked to its endpoint and thereby obtaining the length and angle.

Robotics system

The robotic system for automatic removal of ribs from belly pieces comprised the following :

1. An industrial robot

2. A custom tool, able to loosen one rib at a time, while fixating the product so the other ribs maintained their position.

3. An optical sensor (second meat piece sensor), used for starting the process of loosening the ribs

The process was as follows:

• After measurement by the measuring system, the product continued to the

second meat piece sensor, which triggered the activation of the industrial robot and the loosening of the ribs.

• The robot looped through each position, angle and length, received from the measuring system. The process may be performed using conveyor tracking, but otherwise, the product as in this case stopped when it reached the second meat piece sensor.

• The robot looped according to the information received from the measuring

system :

o It moved to the start position of a rib, rotated the tool to the angle of the rib, and triggered the tool with the rib length,

o It then detached from the product, a few centimeters, before continuing to the next rib.

• When all ribs were loosened, the robot returned to the initial position.

The rib puller for an industrial robot has thus been tested, where the measuring system determined the position, angle and length of the ribs in a belly piece from where the membrane (pleura) above the ribs was removed. The industrial robot handled the rib puller based on the information received from the measuring system and loosened all the ribs in a non-moving belly pieces in less than 25 sec and without breaking the ribs.

List of reference signs

1. Counter hold

2. Pull bar

3. String 4. Holding-down bar

5. Loading means

6. First handle

7. Motor such as a pneumatic system

8. Belly meat piece

9. Ribs

10. Attachment device for connecting the tool to an industrial robot

11. Piston

12. Piston guide

13. Locking plate for shaft

14. Conveyor belt

15. First meat piece sensor

16. Second meat piece sensor

17. Receiving sensor e.g. camera for recording red light 'red camera'

18. Receiving sensor e.g. camera for recording blue and/or green light 'blue camera'

19. Red light source

20. Blue or green light source

21. Working zone such as a working zone for removing bones

22. Meat piece/product

23. Cleaning plug

24. Piston

25. Guide

26. Ski

27. Light wave