WO1999033022A1

WO1999033022A1 - An apparatus for monitoring an animal related area

Info

Publication number: WO1999033022A1
Application number: PCT/SE1998/002408
Authority: WO
Inventors: Michael J. Street; Robin D. Tillet; John A. Marchant
Original assignee: Alfa Laval Agri Ab
Priority date: 1997-12-19
Filing date: 1998-12-21
Publication date: 1999-07-01
Also published as: SE9704777L; AU1992999A; SE9704777D0

Abstract

An apparatus for monitoring an animal related area comprises an image capturing device (4a, 4b, 4c, 4d, 4e) arranged on at least one location in said animal related area, said image capturing device (4a, 4b, 4c, 4d, 4e) being associated with a control means. According to the present invention, at least one illuminating device (6a, 6b, 6c, 6d, 6e) is arranged to illuminate said object for casting a shadow of said object on said surface (3a, 3b, 3c, 3d, 3e), said image capturing device (4a, 4b, 4c, 4d, 4e) being directed towards said surface (3a, 3b, 3c, 3d, 3e), and said control means being adapted to identify a characteristic of an object outgoing from said viewed shadow.

Description

An apparatus for monitoring an animal related area

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an apparatus for monitoring an animal related area, comprising an image capturing device arranged on at least one location in said animal related area, said image capturing device being associated with a control means.

Such an apparatus is known from WO 97/15901, according to which an injured animal having a bleeding wound is recognised by performing colour analysis, such as Red-Green-Blue (RGB) analysis, of an image captured by a video camera.

It is also known to perform contour analysis of a captured image, see e.g. DE-A-3 742 867.

SUMMARY OF THE INVENTION

Colour analysis or contour analysis of an image is useful in cases where the colours or contrasts are distinct. However, in a dirty and sparsely illuminated environment, colours and contours tend to be less distinct and are accordingly difficult to analyse.

It is therefore an object of the invention to overcome the difficulties of performing analysis of an image captured in an animal related area.

This object has been achieved by an apparatus of the initially defined kind, which is characterised in that at least one illuminating device is arranged to illuminate said object for casting a shadow of said object on a surface, said image capturing device being directed towards said surface, and said control means being adapted to identify a characteristic of an object outgoing from said viewed shadow. Hereby, a quick analysis of the position of the object is achieved.

Suitably, said control means is adapted to translate a movement of the shadow to a movement of said object. Hereby, a quick analysis of the object's movement is achieved.

Preferably, at least one characteristic of said surface is stored in a memory of said control means, said control means being adapted to recognise said characteristic. Hereby, a safer image analysis is achieved.

Suitably said characteristic is at least one of a colour, a pattern and a shape. Hereby, is achieved a clear identification of said surface.

Preferably, at least one characteristic of a shadow of said object is stored in said memory. Hereby, is achieved a clear identification of the shadow of said object.

Suitably, at least one standard colour content of said shadow is stored in said memory. Hereby is achieved a safe identification of said shadow.

Preferably, possible positions of said object shadow are stored in a memory of the control means, for allowing identification of the real time position thereof. Hereby, a quicker image analysis is performed.

Suitably, said control means is adapted to perform contour analysis of an image captured by said image capturing device.

Preferably, said control means is adapted to perform colour (RGB) analysis of an image captured by said image capturing device. Hereby, a colour content of the shaded surface are established, and furthermore the colour content of a part of the surface, which is not shaded, in order to distinguish them from one another. Suitably, said surface is arranged substantially vertically, said light source being arranged substantially above the animal related area and is directed in such a way that the surface is illuminated by said light source, while no object is in said animal re- lated area, but is at least partly in the shadow of the object while in the animal related area. Hereby is achieved an easily established relationship between the movement of the object and the movement of the shadow cast on the surface.

Preferably, said surface is substantially flat. Hereby, image analysis only needs to be performed in two dimensions.

Suitably, said light source has an illumination axis, which is substantially 45° to said vertically arranged surface. Hereby is achieved that a certain horizontal movement of the object corresponds to the same vertical movement of the object's shadow on the vertical surface.

Preferably, said animal related area comprises at least a part of a cow shed.

Suitably, said object is a movable stall equipment, such as a gate or a robot arm. Hereby, said movable stall equipment is operated in response to the result of the performed image analysis.

Suitably, said object is an animal identifiable in real time by said control means. Hereby, a position or a movement of said animal is possible to establish.

Preferably, said object is an animal and said animal related area comprises an animal stall for performing an animal related operation by means of a robot having a robot arm, said robot arm being movable in response to said control means. DRAWING SUMMARY

The invention will now be described in more detail with reference to the accompa- nying drawings, in which

Figure 1 illustrates a first embodiment of the invention including a cow and a gate casting a shadow on a defined surface, respectively.

Figure 2 illustrates a second embodiment of the invention including a cow and a robot arm casting a shadow on a defined surface, respectively.

Figures 3 a and 3b illustrate a third embodiment of the invention including a cow casting a shadow on a defined surface.

Figures 4a and 4b illustrate examples of defined surfaces.

Figure 5 illustrates an animal shed provided with a plurality of defined surfaces.

DETAILED DESCRIPTION

Figure 1 illustrates a cow in an animal related area 1, in the form of a gateway la, which is provided with a wall 2, having a defined surface 3 a. Other gateway demarcations have been omitted for clarity reasons.

An image capturing device 4a, such a video camera or a digital camera, is pivotally arranged on a wall, a post or the like, and is possible to be directed towards the surface 3a by means of a motor. Both the image capturing device 4a and the motor are associated with a control means (not shown). An illumination means 6a associated with the control means is arranged such that a cow expected to be in front of the surface 3 a will cast a shadow 2a of the cow thereon. Analysis of images captured by the image capturing device 4a is performed by the control means in a known manner, e.g. by colour analysis or contour analysis.

In front of the cow, there is provided a gate 5 with opening/closing means 5 a associated with said control means. Closing and opening of the gate 5 prevents or allows the cow to proceed further. An illumination means 6b associated with the control means is arranged to illuminate the gate 5 from above, so that the gate casts a shadow 2b on the defined surface 3b. In order to create a sharp shadow 2a, 2b, it is preferable that the lamp is of the halogen type and is provided with a directing reflector or shade. A further video camera 4b associated with the control means is arranged to view the shadow 2b cast by the gate 5. Preferably, the image capturing device 4b is arranged at a position obliquely above the gate. Underneath the area where the gate 5 is expected to be viewed, a part of the floor is provided with a de- fined surface 3b.

The gate 5 is accordingly opened and closed in response to the image capturing devices 4a and 4b, separately or in combination.

In Figure 2, the animal related area 1 is shown as an animal stall lb for milking an animal by means of a milking robot 8 with a robot arm 9, a gripper 10 for gripping a teat cleaning means, a teatcup or the like, provided for performing teat cleaning, milking etc. The milking robot 8 is also associated with the control means. The stall lb is defined by the wall 2 and further delimitations, which have been omitted for clarity reasons.

An illuminating means 6a is arranged such that the cow casts a shadow 2a on the defined surface 3a of the wall 2. A pair of image capturing devices 4a, associated with the control means are arranged to view the wall 2 from different directions. A further illuminating means 6c is arranged to illuminate the robot arm 8 from above, and a further image capturing means 4c associated with the control means is arranged to view a shadow 2c cast by the robot arm 8 on a defined surface 3 c on the floor provided underneath the area where the robot arm 9 is expected to be in operation. The image capturing device is arranged at a position to view the surface 3c obliquely from above.

A still further illuminating means 6d is arranged at such a position, that a further image capturing device 4d associated with the control means and arranged on the robot arm 9 is able to view a sharp shadow (not shown) cast by the udder on the surface 3 a. Alternatively, a surface arranged closer to the udder may be used for achieving a better resolution of the image.

Consequently, the milking robot operates in response to the different image capturing devices 4a, 4c, 4d. As a plurality of illuminating means 6a, 6c, 6d lit simultaneously may cause diffuse shadows, it is desirable that the different illuminating means are individually controllable, i.e. the control means is programmed to turn on and off the illuminating means 6a, 6c, 6d depending on which image capturing de- vice 4a, 4c, 4d is momentarily in operation.

It should be understood that it is not necessary to utilise all of the described combinations of illuminating means and image capturing devices 6a, 4a; 6c, 4c; 6d, 4d together. Instead, it is possible to utilise one such combination - e.g. 6a, 4a - to- gether with another kind of equipment. As an example, the combination of the illuminating means 6a and image capturing device 4a may be used together with a teat locating means of another kind than described above, such as a laser sensor or an ultrasonic sensor.

In Figure 3a, the defined surface 3e is arranged behind the cow in a milking stall lb (stall gates, posts etc. have been omitted for reasons of clarity). A milking robot 8, of the kind disclosed in connection with Figure 2, is arranged to perform animal related operations, such as teat cleaning and milking. In Figure 3 a, the gripper 10 of the robot arm 9 holds a teatcup, which is to be attached onto a teat of the cow. In order to perform this, a teat locating means of the kind described in connection with Figure 2 is disclosed. However, any suitable kind of teat locating means may be used, such as a laser sensor or an ultrasonic sensor.

Above the cow, an illuminating means 6e is provided to cast a shadow on the defined surface 3e behind the cow. An image capturing device 4e is provided to view the defined surface 3e and in particular the cast shadow.

A vertical downward movement of the shadow on the surface 3 corresponds to a movement of the cow away from the surface 3, whereas a vertical upward movement of the shadow on the surface 3 corresponds to a movement of the cow towards the surface 3.

In order to more exactly establish the movements of the cow, the defined surface 3e is arranged vertically, and the illuminating means 6e is arranged with an illuminating axis of about 45° in relation to the vertical surface 3e. Accordingly, when the cow moves a distance L away from the surface, the shadow of the cow moves substantially the same distance L, but vertically downwards; cf. Figure 3b and vice versa.

The described correlation is particularly advantageous during teatcup attachment. When a teatcup has been placed underneath a teat, and the robot arm 9 is about to attach a teatcup onto the teat, the cow may move a distance L away from the surface 3e. The teat locating means 4 on the robot arm 8 is then at such a location that when the cow moves, it is unlikely that the teat locating means is able to immediately find the teats. The robot arm 9 would need to be retracted and start the teat location from the beginning again. However, as the shadow of the cow moves a distance L, which substantially corresponds to the moved distance L of the cow, the control means associated with the image capturing device 4, the illuminating means 6 and the robot 8 is adapted to move the teatcup, by means of the robot arm 9, a distance L and in the same direction as the moved direction of the cow (i.e. to the right in figure 3b). This is also called tracking.

It should be noted that even though the illuminating means 6e is arranged at a pre- cise angle, the geometrical correlation to the shadow will only be exact when the cow is in the position shown in figure 3 a, since when the cow moves a distance, the real angle to the contour of the shadow changes. However, the result is accurate enough to used for tracking.

It should be understood that the embodiment of Figures 3a and 3b may be used alone or in combination with the embodiments of Figures 1 and 2.

In order to better perform image analysis, the defined surface 3a, 3b, 3c, 3d, 3e of the described embodiments are flat and have a well definable colour, such as white, yellow, red or any suitable colour that suits the image analysis used by the control means. Alternatively, it may have mixed colours forming a pattern, e.g. different coloured stripes (see Figure 4a) or checked black and white (see Figure 4b).

In Figure 5, an animal related area 1 in the form of a part of or a whole animal shed is shown. It comprises two gateways la with and without gates and the animal stall lb shown in Figures 2 and 3. Accordingly, all of the embodiments shown in Figures 1, 2, 3a and 3b are utilised in combination or separately. Consequently, in Figure 5, two modified gates 5 (cf. Figure 1) are provided to allow an animal to enter or to exit the animal stall lb (cf. Figure 2). Underneath the gates 5, there are provided de- fined surfaces 3b. It should accordingly be understood that a complete wall or floor, or any part of a wall or a floor may constitute or be provided with said defined surface 3a, 3b, 3c, 3d, 3e. Furthermore, wall and floor partitions having the defined surface 3a, 3b, 3c, 3d, 3 e are possible to arrange at places where needed, cf. the wall and floor portions at the animal stall lb and at the gate 5.

It should also be understood that the surfaces 3 may need cleaning, especially those on the floor. It is therefore suggested that spray nozzles are provided at the surfaces 3a, 3b, 3c, 3d, 3e, and that they are constituted by a material, which is easily cleaned by rinsing.

As mentioned above, all the image capturing devices 4a, 4b, 4c, 4d, 4e are associated with a control means. It may however be advantageous to provide one control means per image capturing device. If any or several of the cameras need to cooperate, there may be a common control means for the separate control means. Alternatively, the control means of selected cameras may be interconnected.

The same relates to the control means of the gate 5 and the robot 8.

OPERATION

The presence of an animal in the animal space 1, la, lb is established by anyone of the image capturing devices 4a, 4b etc. In addition to this, the operation and or the position of animal related devices are established; in the gateway la, the operation and/or the position of the gate 5 is established and in the animal stall the operation and/or position of the robot arm 9 is established.

While establishing the presence of an object, such as animal, an alien item (e.g. a tool box), or the operation and/or the position of an object, such as a gate or a robot arm, the image capturing device 4a, 4b etc. is directed towards the object in front of the defined surface 3 a, 3b etc. In order to cast a shadow of the object on the surface, the illuminating device or devices 6a, 6b etc. is/are lit and is/are directed towards the object and the defined surface 3a, 3b etc.

The image capturing device captures an image of the viewed object shadow. The image is analysed by the control means, which generates a signal to the gate opening/closing means 5a, the robot 8 (including the robot arm 9 and the gripper 10).

If an abnormal situation has occurred, e.g. that the gate is standing in the wrong po- sition, the robot arm is not responding to commands or that a cow has run into a state of panic, a warning signal is generated to a buzzer or a mobile telephone carried e.g. by the farmer.

The described apparatus and method are applicable to all animal related areas where animals to be milked are to be monitored, such as cows, sheep, goats, buffaloes and horses.

Claims

1. An apparatus for monitoring an animal related area (1, la, lb), comprising an image capturing device (4a, 4b, 4c, 4d, 4e) arranged on at least one location in said animal related area (1), said image capturing device (4a, 4b, 4c, 4d, 4e) being associated with a control means characterised in that at least one illuminating device (6a, 6b, 6c, 6d, 6e) is arranged to illuminate said object for casting a shadow (2a, 2b, 2c, 2d) of said object on a surface, said image capturing device (4a, 4b, 4c, 4d, 4e) being directed towards said surface (3a, 3b, 3c, 3d, 3e), and said control means being adapted to identify a characteristic of an object outgoing from said viewed shadow (2a, 2b, 2c, 2d).

2. An apparatus according to anyone of the preceding claims, wherein said control means is adapted to translate a movement of the shadow (2a, 2b, 2c, 2d) to a move- ment of said object.

3. An apparatus according to claim 1 or 2, wherein at least one characteristic of said surface (3a, 3b, 3c, 3d, 3 e) is stored in a memory of said control means, said control means being adapted to recognise said characteristic.

4. An apparatus according to anyone of claims 1 to 3, wherein said characteristic is at least one of a colour, a pattern and a shape.

5. An apparatus according to anyone of the preceding claims, wherein at least one characteristic of a shadow (2a, 2b, 2c, 2d) of said object is stored in said memory.

6. An apparatus according to anyone of the preceding claims, wherein at least one standard colour content of said shadow (2a, 2b, 2c, 2d) is stored in said memory.

7. An apparatus according to anyone of the preceding claims, wherein possible positions of said object shadow (2a, 2b, 2c, 2d) are stored in a memory of the control means, for allowing identification of the real time position thereof.

8. An apparatus according to anyone of the preceding claims, wherein said control means is adapted to perform contour analysis of an image captured by said image capturing device (4a, 4b, 4c, 4d, 4e).

9. An apparatus according to anyone of the preceding claims, wherein said control means is adapted to perform colour (RGB) analysis of an image captured by said image capturing device (4a, 4b, 4c, 4d, 4e).

10. An apparatus according to anyone of the preceding claims, wherein said surface (3a, 3b, 3c, 3d, 3 e) is arranged substantially vertically, said light source being ar- ranged substantially above the animal related area and is directed in such a way that the surface (3a, 3b, 3c, 3d, 3 e) is illuminated by said light source, while no object is in said animal related area, but is at least partly in the shadow (2a, 2b, 2c, 2d) of the object while in the animal related area.

11. An apparatus according to claim 10, wherein said surface (3a, 3b, 3c, 3d, 3e) is substantially flat.

12. An apparatus according to 10 or 11, wherein said light source has an illumination axis, which is substantially 45┬░ to said vertically arranged surface (3a, 3b, 3c, 3d, 3e).

13. An apparatus according to anyone of the preceding claims, wherein said animal related area comprises at least a part of a cow shed.

14. An apparatus according to anyone of the preceding claims, wherein said object is a movable stall equipment, such as a gate (5) or a robot arm (9).

15. An apparatus according to anyone of the claims 1 to 13, wherein said object is an animal identifiable in real time by said control means.

16. An apparatus according to claim 15, wherein said animal related area comprises an animal stall for performing an animal related operation by means of a robot hav- ing a robot arm (9), said robot arm being movable in response to said control means.

17. A method of monitoring an animal related area, by utilising an apparatus according to anyone of the preceding claims, including

- illuminating said object by means of at least one illuminating device (6a, 6b, 6c, 6d, 6e) for casting a shadow (2a, 2b, 2c, 2d, 2e) of said object on said surface (3a, 3b, 3c, 3d, 3e),

- directing said image capturing device (4a, 4b, 4c, 4d, 4e) towards a surface (3 a, 3b, 3c, 3d, 3 e) having an appearance recognisable by said control means,

- identifying, by means of said control means, a characteristic of an object between said image capturing device (4a, 4b, 4c, 4d, 4e) and said surface (3a, 3b, 3c, 3d, 3e) outgoing from the viewed shadow (2a, 2b, 2c, 2d).