WO2025052208A1

WO2025052208A1 - Milking system

Info

Publication number: WO2025052208A1
Application number: PCT/IB2024/058306
Authority: WO
Inventors: Leandro DE NIJS
Original assignee: Lely Patent NV
Current assignee: Lely Patent NV
Priority date: 2023-09-04
Filing date: 2024-08-27
Publication date: 2025-03-13
Anticipated expiration: 2026-03-04
Also published as: NL2035731B1

Abstract

A milking system (1) comprises a milking stall (2) with robotic milking means (6) and a feeding system (9) for dispensing concentrate to a dairy animal. The feeding system comprises a feed trough (15), a feed-metering device and a residual feed-measuring device (10) for measuring concentrate which has remained behind in the feed trough. The residual feed-measuring device comprises a 3D camera (11) and a screening device (12) in order to screen off the 3D camera from scattered light. The 3D camera is configured to take a 3D image of the feed trough after the dairy animal has left the milking stall, and to determine a surface on the basis thereof. The residual feed-measuring device is configured to determine the amount of residual feed from the 3D surface produced and a reference surface of an empty feed trough. The screen only starts to operate after a visit by the dairy animal, and ensures an accurate measurement. The 3D camera can automatically determine the reference image from the emptiest feed trough of the last N measurements.

Description

Milking system

The present invention relates to a milking system for milking a dairy animal, in particular a cow, in a milking operation and comprising a milking stall with robotic milking means and a feeding system for dispensing concentrate to a dairy animal during a visit of said dairy animal to the milking stall, wherein the feeding system comprises a feed trough and a feed-metering device, as well as a residual feed-measuring device for measuring concentrate that has remained behind in the feed trough after said visit.

In many cases, milking devices are provided with feeding devices which are able to dispense concentrate to the dairy animals. Concentrate is important in order to provide the dairy animals with sufficient amounts of nutrients, and helps to keep the animals calm during milking. In the case of robotic milking devices, such feeding devices are often the only providers of concentrate, since they serve as means to lure the dairy animals to the milking robot. In addition, it is easier to provide the necessary automatic feeding apparatus and control unit at the milking device which is likewise provided with a control unit and the like, so that, for example, an animal recognition means, cabling, optionally a box structure, etc., only has to be supplied once.

On occasion, a dairy animal does not eat all the concentrate during the milking operation, so that some concentrate remains behind in the trough after said milking operation. On the one hand, it is important to know that concentrate remains behind, as this may be an indication that the dairy animal may suffer from a health issue. On the other hand, it is important to know how much concentrate is still in the trough because it may indicate the severity of the health issue, but also because the amount has to be deducted from the amount of concentrate which is metered out for and consumed by the next dairy animal in the milking device.

EP1236393A2 describes an autonomous feeding system with a feed trough and which is able to estimate how much feed is (still) present in the feed trough by means of a camera. However, no mention is made of a milking system with a milking stall, so that this system would sooner lure dairy animals away from the milking device or milking robot and in any case is of a more complicated construction overall. Neither is any explanation given about how the camera is able to determine this amount of feed, let alone how this can be done in a reliable way.

It is an object of the present invention to improve a milking device of the indicated kind in such a way that it can reliably measure the amount of residual feed without negatively affecting animal behaviour or the milking capacity of the milking device. To achieve this object, the invention provides a milking system for milking a dairy animal, in particular a cow, in a milking operation and comprising a milking stall with milking means and a feeding system for dispensing concentrate to a dairy animal during a visit of said dairy animal to the milking stall, wherein the feeding system comprises a feed trough and a feed-metering device, as well as a residual feed-measuring device for measuring concentrate remained behind in the feed trough after said visit, wherein the residual feed-measuring device comprises a 3D camera, in particular a time-of-flight camera, as well as a screening device for screening off the 3D camera from scattered light from, in particular, the feed trough, after said visit, wherein the 3D camera is configured to produce a 3D image of the feed trough after said visit, wherein the residual feed-measuring device is configured to determine the amount of concentrate in the feed trough on the basis of the 3D image produced.

The invention uses the insight that the 3D camera is able to measure the residual feed more reliably after the visit of the dairy animal, if it is better screened off from, in particular, ambient light, and this can be achieved by providing a screening device. In particular, reflections of the ambient light onto the feed trough itself, and possibly onto components in the surroundings of the feed trough, which almost always consist of somewhat shiny metal or at most of somewhat shiny plastic, may have a disruptive effect on a 3D camera, in particular a time-of-flight camera. The latter works with emitted light, for example modulated light, in which the position of the surface of the residual feed is determined from the phase difference using the light reflected by the residual feed. The camera could also perform a direct distance measurement by determining the transit time of an emitted light pulse. However, if a relatively strong signal of ambient light is reflected off shiny parts of or around the feed trough, such as the milking stall itself, this has a disruptive effect during imaging. In addition, the level of (residual) feed in the feed trough often varies considerably, so that the lighting will already vary due to the nature of the matter. The screening device which becomes active after the visit of the dairy animal, when the image of the residual feed has to be made, counteracts this disruptive effect.

Particular embodiments are described in the dependent claims, as well as in the following part of the description.

In embodiments, the screening device comprises a flap part which is pivotable over the feed trough by the residual feed-measuring device after said visit, wherein the 3D camera is fitted down below said flap part, in such a way that the 3D camera is able to take the 3D image after it has pivoted to over the feed trough. By means of the flap, it is then, on the one hand, possible to move the 3D camera from a position outside the reach of the animal to a position in which it is able to measure the residual feed, namely right above the feed trough. On the other hand, the flap ensures that ambient light is screened off, so that the latter cannot shine into the 3D camera in a disruptive way.

Alternatively or additionally, the feed trough can be pivoted out from a first position in the milking stall in which the dairy animal has access to the feed trough, to a second position outside the milking stall and outside the reach of said dairy animal, in which the 3D camera is positioned in order to take said 3D image of the feed trough in the second position. In this case, it is therefore not the 3D camera which is moved, but actually the feed trough. In many (robotic) milking devices, the feed trough is moved outside the milking stall after milking. If the feed trough is inaccessible to the dairy animal, it will be more likely to leave the milking stall in order to make room for a next dairy animal. By placing the 3D camera in such a way that it rather sees the feed trough in the second position, the residual feed, which can after all only be determined after the milking operation, at least after the visit by the dairy animal, can be reliably measured. In this alternative, too, the 3D camera remains out of reach of the dairy animal, so that there is less risk of soiling, misalignment and the like.

In embodiments, the screening device extends on at least two sides of the 3D camera. In particular, the screening device extends on at least two sides of the 3D camera as at least one component of the milking stall. For example, the screening device extends on the rear side of the 3D camera, as well as at least partly around the camera. This is often the case in the embodiments in which the 3D camera is fitted down below a flap part. It is also possible for the screening device to extend only around the 3D camera. In this case, the 3D camera is, for example, surrounded by one or more components of the robotic milking device, such as a housing or milking stall component. It is also possible to provide a specific screening component for that purpose, for example substantially screening off the feed trough swung out to the second position.

In embodiments, the residual feed-measuring device is configured to determine the volume of residual feed from the 3D image produced and a 3D reference image of the feed trough in an empty state. In general, a 3D image from a 3D camera consists of a collection of pixels, with each pixel being associated with a distance to the camera. Each pixel is also associated with a viewing direction which is dependent on the optics of the camera. In most cases, the optics are fixed and have a known focal distance, but a zoom lens with variable focal distance is not excluded. With a known viewing direction and distance per pixel, a spatial representation of objects in the 3D image can be calculated. In particular, the surface of the residual feed in the feed trough is calculated in this case. This calculated surface can then be compared to the 3D reference image of an empty feed trough. The volume between the calculated surface of the residual feed and the surface of the empty feed trough calculated in the same manner then forms the volume of the residual feed. The volume is in this case determined by determining the volume between the surface as measured using the 3D camera and the surface of the reference image of the empty trough, as this is after all the volume occupied by the residual feed. In this case, the surface is determined, in particular, by locally measuring the (average) height for a number of cells (pixels), such as according to a predetermined grid, and subtracting the reference height at this location therefrom, resulting in a local feed height. The volume is then a summation of all local feed heights times the respective surface of the local cell.

The 3D reference image of the feed trough may be determined in all kinds of ways. For example, this has been determined once during the installation of the milking device. In practice, however, the alignment between the 3D camera and the feed trough may change. After all, these move with respect to each other, during which process a disturbance, or at least a change, may occur, such as due to wear or soiling. However, in particular, it is possible that a feed trough may be deformed or becomes misaligned due to load being exerted by a dairy animal, such as with the snout or even by standing therein. In particular, the 3D camera is thus configured to determine the 3D reference image of the feed trough in the empty state from the 3D images produced during the previous N visits of any dairy animal as the 3D image of the feed trough that has the greatest average distance to the 3D camera, with N>= 3. In this case, use is made of the insight that, in the majority of cases, the feed trough will be emptied completely, thus leaving only an empty feed trough. If a change in the alignment has already occurred, then the 3D reference image will be updated dynamically in this way. The risk of residual feed being left behind in the feed trough during N successive visits can virtually be excluded, that is to say, it is easily possible to choose the number N in such a way that this situation, should it arise, is quickly remedied during a subsequent visit of a dairy animal. The numerical value for N, which is 3 in this case, may obviously also be chosen to be different, in particular to be greater, for example 7.

The invention will now be explained in more detail by means of a few nonlimiting examples, as well as the drawing, in which: - Figure 1 shows a highly diagrammatic top view of a milking system according to the invention;

- Figure 2 shows a diagrammatic sectional view of a residual feedmeasuring device of the milking system according to Figure 1 ; and

- Figure 3 shows a diagrammatic sectional view of an alternative residual feed-measuring device of a milking system according to the invention.

Figure 1 shows a highly diagrammatic top view of a milking system 1 according to the invention.

The milking system 1 comprises a milking stall 2 with an exit fence 3 and an entry fence 4 around a milking station 5. A milking robot 6 comprises a robot cabinet 7 and a robot arm 8. A feeding system is denoted by reference numeral 9. In addition, the milking system 1 comprises a residual feed-measuring device 10 with a camera 11 , a screen and a suspension means 13. A control unit is denoted by reference numeral 14.

The feeding system 9 comprises a feed trough 15 on an arm 16 which is pivotable about an axle 17 in the directions of double arrow A by means of actuator 18, as well as a feed-metering device 19 with a tube 20.

The milking system 1 according to the invention comprises a milking stall 2. The variant shown here has an exit fence 3 and an entry fence 4 on a long side. Alternatively, other configurations for the fences may also be provided, such as an exit fence on the short side near the feed trough 15, and an entry fence on the opposite short side.

The milking stall 2, including the fences 3 and 4, surrounds the milking station 5, where a dairy animal, such as a cow, can be milked. To this end, a milking robot 6 is provided. The latter is only illustrated in a highly diagrammatic manner, as a robot cabinet 7 with a robot arm 8 for attaching milking cups (not shown here) to the teats of the dairy animal. The details of such a milking robot are generally known in the prior art, but are of no further importance to the invention, so that they do not have to be explained in any more detail here.

The feeding system 9 comprises a feed trough 15 into which concentrate can be metered, such as pellets, and, optionally, additives such as propylene glycol or water, by means of the feed-metering device 19. To this end, a tube 20 is provided from the feed-metering device 19 to the feed trough 15. As is illustrated here, the tube 20 may partly run via the arm 16, but no other way of getting the feed into the feed trough is excluded.

The feed trough 15 is pivotable to a position 15' outside the milking station 5, indicated by means of the dashed line. To this end, the arm 16 which supports the feed trough 15 is pivotable about an axle 17, and rotatable by means of an actuator 18. Pivoting the feed trough 15 serves several purposes. Firstly, it ensures that feed is taken out of reach of the dairy animal. As a result thereof, it will quickly leave the milking station 5, so that the milking system becomes available for a new milking operation of a new dairy animal. Secondly, pivoting makes it possible to place the feed trough 15 under a screen 12. This screen 12 surrounds a 3D camera 11 and protects it as much as possible from ambient light. The aim thereof is explained below.

The 3D camera 11 optically measures the amount of residual feed, i.e. the feed that has remained behind in the feed trough 15 after a dairy animal has visited the milking system 1 , irrespective of whether it has been milked or not. Residual feed may remain behind if the dairy animal has not had sufficient time to eat, was disturbed during its visit to the milking system or, and then in particular, if it has less of an appetite for one reason or another. The latter may be a signal that something is wrong with the dairy animal, in particular with its health. Therefore, measuring residual feed is an important means to keep an eye on the dairy animal, and in particular its health. It is therefore also important that the residual feed is measured accurately.

Measuring the residual feed with the camera 11 is done optically and therefore it is important to exclude as much of the undesirable ambient light as possible. To this end, a screen 12 is provided around the camera 11. This screen 12 may be a simple cover which is connected to the suspension means 13 of the camera. Such a cover may, for example, screen off the side from where most light comes, for example a window. Obviously, it is possible to provide the screen 12 around the camera 11 as much as possible, so that as much as possible ambient light can be blocked out. The screen 12 may also be provided as a completely independent component of the milking system 1. However, it is also possible to provide the screen 12, and thus the position 15', near and/or between other components of the milking system, in particular near the robot cabinet 7 of the milking robot 6. The milking robot 6 often comprises a separate cabinet with power supply equipment, a vacuum system, cleaning means, etc., wherein the screen 12 may be provided so as to be partly surrounded by the robot cabinet 7 and/or said separate cabinet.

Advantageously, at the spot 15’, the feed trough 15 together with the screen 12 forms a space which is closed as much as possible. Obviously, in this case, the camera 11 itself will emit the necessary light. For example, the camera 11 comprises a built-in light source to this end, such as LEDs. Examples are infrared LEDs, but also laser diodes or the like.

The camera 11 is a 3D camera in order to be able to determine the amount of concentrate in the feed trough optically. In this example, it is a time-of-flight camera (ToF camera). This emits frequency-modulated light at a modulation wavelength , and determines the phase difference A(p between the reflected light and the emitted light. From this phase difference, the camera then calculates the distance d from d = Acp * A I 4TT. This is performed for every image point of the camera by means of integrated electronics. From the distance d and the direction in the image field which is known for each image point and which is known from the optical properties of the optics of the camera, such as in particular the focal distance, the position of the reflective object (part) can be determined, in this case the residual feed, or the feed trough if there is no residual feed present. In this way, the surface of the residual feed is scanned and reconstructed, from which the amount, at least the volume, is deducted by the 3D camera 11 , at least the control unit 14. This is explained in more detail with reference to Figure 2.

Alternatively, the camera 11 may be a different type of 3D camera, such as a "structured light" camera, which emits a specific pattern of light and dark parts, and determines how far away these objects are from the camera from the deformation in this pattern on objects in the image field. Stereo cameras are not excluded, but are often less suitable due to the lack of structure of the residual feed, making it difficult to solve the correspondence problem.

Figure 2 shows a diagrammatic sectional view of a residual feed-measuring device 10 of the milking system 1 according to Figure 1. It again shows the 3D camera 11 inside the screen 12. The emitted bundle of light reflects off the residual feed 21 , with only the directions of bundles 22-1 , ..., 22-n being shown, as these are picked up by nine image points of the camera 11 . In practice, there will be more and there will be, for example, 100 by 100 image points or even more.

Each of the bundles 22-1 to 22-n reflects off a part of the residual feed 21 or off the feed trough 15 itself. From the reconstructed surface of the residual feed 21 and the known reference surface of the empty feed trough 15 stored in the 3D camera 11 of the control unit 14, the volume of the residual feed is determined by determining the height hi between this reconstructed surface and the reference surface for each bundle 22 -1 , ... 22-n, and by multiplying this height with the surface of the part of the image captured by that image point, the volume of the residual feed 21 is determined after summing it up across all image points. In the illustrated example, there is not very much residual feed, so that the bundles 22-1 and 22-n indicate a height h of zero. In practice, it is important to determine the reference surface accurately. To this end, the camera 11 may, for example, take an image of the entirely empty feed trough 15 and store it. This may be done, for example, at the factory, during installation, and every time the feed trough 15 is cleaned, as the feed trough is after all completely empty on these occasions. However, this manual work is not required, and the camera 11 may be configured, optionally in combination with the control unit 14, to determine the reference surface automatically. It should be noted here that the control unit 14 may serve to process the images from the camera 11 to form surfaces and the like. This functionality may also be incorporated in the camera 11. Below, the control unit 14 will therefore no longer be mentioned separately for this purpose. In order to determine the reference surface, the camera 11 determines the image from the last /V milking operations which has the lowest average height h, obviously in each case after the dairy animal has left the milking system 1 . Without knowledge of the reference surface, this cannot be determined exactly, but it approximately corresponds to the image with the largest average distance to the camera 11 . In this case, the number N is a moderate number, such as for example 3, 4 or 10. In this case, it is assumed that most dairy animals will indeed essentially finish the feed in the feed trough 15, so that there is a virtually 100% chance that there will have been at least one entirely empty feed trough 15 among the past N measurements, which image will supply the reference image. Thus, the camera 11 can already adjust the reference image, if necessary, after every milking operation. Thus, the camera 11 can immediately take into account, for example, a deflection or other deformation of the feed trough 15. After all, there will be occasions when a dairy animal steps into the feed trough 15, so that it is not unimaginable that the latter deforms.

Figure 3 shows a diagrammatic sectional view of an alternative residual feed-measuring device 10' of a milking system according to the invention. In this alternative, the camera 11 is attached to the screen 12' which is in turn attached to an arm 23 by means of a support 24. The arm 23, and thus the screen 12' with camera 11 , is movable in the direction of the double arrow B.

In this version, the feed trough 15' is fixedly arranged, and the screen 12' is moved over the feed trough 15' after the milking operation by means of an actuator (not shown). In this case, the screen 12' serves as a protection against ambient light, and also as a screen to prevent the dairy animal from continuing to eat. For the remainder, the operation of the residual feed-measuring device 10' is identical to that of the device 10 shown in Figure 10.

Claims

1. Milking system for milking a dairy animal, in particular a cow, in a milking operation and comprising a milking stall with robotic milking means and a feeding system for dispensing concentrate to a dairy animal during a visit of said dairy animal to the milking stall, wherein the feeding system comprises a feed trough and a feed-metering device, as well as a residual feed-measuring device for measuring concentrate that has remained behind in the feed trough after said visit, wherein the residual feed-measuring device comprises a 3D camera, in particular a time- of-flight camera, as well as a screening device for screening off the 3D camera from scattered light from, in particular, the feed trough, after said visit, wherein the 3D camera is configured to produce a 3D image of the feed trough after said visit, wherein the residual feed-measuring device is configured to determine the amount of concentrate in the feed trough on the basis of the 3D image produced.

2. Milking device according to Claim 1 , wherein the screening device comprises a flap part which is pivotable over the feed trough by the residual feedmeasuring device after said visit, wherein the 3D camera is fitted down below said flap part, in such a way that the 3D camera is able to take the 3D image after it has pivoted to over the feed trough.

3. Milking device according to Claim 1 or 2, wherein the feed trough can be pivoted out from a first position in the milking stall in which the dairy animal has access to the feed trough, to a second position outside the milking stall and outside the reach of said dairy animal, in which the 3D camera is positioned in order to take said 3D image of the feed trough in the second position.

4. Milking device according to Claim 3, wherein the screening device extends on at least two sides of the 3D camera, in particular as at least one component of the milking stall.

5. Milking device according to one of the preceding claims, wherein the residual feed-measuring device is configured to determine the volume of residual feed from the 3D image produced and a 3D reference image of the feed trough in an empty state.

6. Milking device according to Claim 5, wherein the 3D camera is configured to determine the 3D reference image of the feed trough in the empty state from the 3D images produced during the previous N visits of any dairy animal as the 3D image of the feed trough that has the greatest average distance to the 3D camera, with N>= 3.