Abstract:
An apparatus for milking an animal and provides a milking parlor ( 1 ) including first and second robotic manipulation devices ( 100, 200 ) and a plurality of milking stalls ( 5 ) provided on a platform ( 3 ) moveable relative to the robotic manipulation devices ( 100, 200 ) wherein the robotic manipulation devices ( 100, 200 ) are positioned so as to be capable of simultaneously servicing neighboring milking stalls ( 5 ) on the platform ( 3 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a milking parlour and a method for operating the same and particularly, but not exclusively, to a rotary milking parlour for milking an animal, such as a cow, and to a method for operating the same. 
     2. Description of the Related Art 
     There are various types of milking parlour known in the dairy industry and the present invention is of particular relevance to what is commonly referred to as a rotary milking parlour. This type of parlour is provided with a comparatively large number of milking stalls arranged in a circular configuration on a rotating annular platform and is of particular use in handling a large number of animals. The platform rotates at a relatively low constant speed so that a cow may readily step onto the platform from a stationary holding bay and thereby gain access to a stall. If deemed necessary by an operator, the rotary movement of the platform may be stopped momentarily in order to allow a cow sufficient time to enter (or exit) the platform. The continued rotation of the platform then moves the stall into a position where an operator can perform certain tasks (such as teat cleaning and placement of teat cups on the teats) so as to allow the milking process to begin. The speed of rotation is such that the milking process will have been completed by the time a stall has moved from the cow entry position (where a cow gains entry onto the platform) to a cow exit position (where a cow is permitted to leave the platform). The cow entry and exit points are adjacent one another so as to maximise the time a cow spends in the milking stall. 
     It will be understood that cows may constantly enter and exit a rotary parlour without necessarily stopping the platform rotation and this allows for a large number of cows to be handled. It will be also understood that the movement of the platform results in cows being brought to an operator in turn. The operator is therefore able to remain in one location and concentrate on essential milking tasks without interruptions. 
     There are two main types of rotary milking parlour system, which may be referred to, as the Parallel Rotary system and the Herringbone Rotary system. 
     In a Herringbone Rotary system, a cow stands in a stall facing diagonally towards the outside of an annular rotating platform, in the general direction of rotation. One or more operators stand on the inside of the rotating platform and are thereby provided good access to the side of each cow. Milking equipment is positioned alongside each cow on the inside edge of the platform. 
     In a Parallel Rotary system, a cow stands in a stall of a rotating platform so as to face radially inward towards the centre of rotation of the platform. Operators stood outside the rotating platform are then able to work from the rear of each cow as the cow passes in turn. Because the cows are positioned side by side, the parallel rotary system allows more cows to be accommodated in the same space. 
     In each of these types of rotary parlour, each milking stall is provided with a cluster of four teat cups. These teat cups are attached to the teats of a cow located within the stall so as to allow said cow to be milked. Once the milking process has been completed, an automatic retraction system is typically used to remove the four teat cups simultaneously from the teats. Such a system comprises a cord which is attached to the teat cup cluster and which is retracted automatically at an appropriate time so as to pull the teat cup cluster from the cow. 
     A problem associated with rotary milking parlours is that an operator only has a limited amount of time in which to service a milking stall before the milking stall moves beyond the reach of the operator. An operator may service a milking stall in a number of ways, for example, an operator will typically service a milking stall by moving teat cups from a storage position into a position where they are attached to the teats of a cow stood within the milking stall. Although a teat cup cluster will be typically attached to the teats of a cow before the milking stall has moved a significant distance, unpredictable events such as movement by an unsettled cow can significantly delay the teat cup attachment process. This is not necessarily problematic when a human operator services the milking stalls because the operator can walk with the rotating platform and remain with the particular stall experiencing the delay. However, delays in servicing a stall can be problematic in circumstances where a robot arm is being used for the servicing activity. This is because the robot arm has a fixed position within a milking parlour and so a milking stall will tend to move quite rapidly beyond its reach. This problem is also a particular issue when the speed of the milking stalls is comparatively high. This may be found in large rotary parlours where the linear tangential speed of a stall will be comparatively high for a given angular speed because of the comparatively large platform radius. 
     BRIEF SUMMARY OF THE INVENTION 
     A first aspect of the present invention provides a milking parlour comprising first and second robotic manipulation devices and a plurality of milking stalls provided on a platform moveable relative to the robotic manipulation devices; wherein the first and second robotic manipulation devices are positioned so as to be capable of simultaneously servicing neighbouring milking stalls on the platform; the parlour being characterised in that each robotic manipulation device comprises an arm which is sufficiently extendable to service both a first stall positioned immediately adjacent the robotic manipulation device and a second stall neighbouring the first stall. 
     A second aspect of the present invention provides a method of operating a milking parlour according to the first aspect of the present invention; the method comprising the step of controlling the first and second robotic manipulation devices so that said devices simultaneously service different neighbouring milking stalls on the platform. 
     A milking parlour is described below as comprising first and second robotic manipulation devices and a plurality of milking stalls; wherein information regarding the activity of a robotic manipulation device is sent electronically from said device. Information regarding one of said robotic manipulation devices may be communicated electronically to the other of said robotic manipulation devices. Ideally, information regarding the activity of said two robotic manipulation devices may be exchanged electronically between said devices. Furthermore, the information may comprise data recording the current real-time position of a robotic manipulation device and/or the number of teat cups successfully attached to a cow positioned in a milking stall currently being serviced by a robotic manipulation device. Ideally, the plurality of milking stalls are provided on a platform moveable relative to the robotic manipulation devices. 
     A milking parlour is described below as comprising a first robotic manipulation device and a plurality of milking stalls provided on a platform moveable relative to the robotic manipulation device; and the parlour further comprising an entrance preventing, in use, entry to the platform of more than one animal at any one time; and the parlour being characterised by a second robotic manipulation device wherein the first and second robotic manipulation devices are positioned so as to be capable of simultaneously servicing neighbouring milking stalls on the platform. 
     Also described below is a method of operating a milking parlour having first and second robotic manipulation devices, a plurality of milking stalls provided on a platform moveable relative to the robotic manipulation devices, and an entrance preventing, in use, entry to the platform of more than one animal at any one time; the method comprising the step of controlling the first and second robotic manipulation devices so that said devices simultaneously service different neighbouring milking stalls on the platform. 
     It will be understood that through use of the present invention, a robotic manipulation device may be provided with additional time to service a milking stall. It will also be appreciated that the present invention thereby allows the speed of a platform stall to be increased. If necessary, the rate at which the robotic manipulation device is found to be completing a current activity (i.e. the performance of the robotic manipulation device) can be used to determine whether or not to use the means by which the additional time is provided. In other words, the performance of a robotic manipulation device may be such that the use of an associated second robotic manipulation device is not required. 
     Further advantageous optional features of the invention are set out in the appended dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An embodiment of the present invention will now be described with reference to the accompanying drawing, in which: 
         FIG. 1  is a schematic perspective view of a parallel rotary parlour according to the present invention; 
         FIG. 2  is a schematic part plan view of the rotating platform of the rotary parlour shown in  FIG. 1  wherein the platform is in a first rotary position and two robotic arms are each servicing a different milking stall by moving teat cups one by one from a teat cup magazine to the teats of a cow; 
         FIG. 3  is a schematic part plan view of the rotating platform of the rotary parlour shown in  FIG. 1  wherein the platform is in a second rotary position and the two robotic arms are each completing the servicing of respective milking stalls; and 
         FIG. 4  is a schematic representation of a base unit, a telescopic element, and the robotic arm according to at least one embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A parallel rotary parlour  1  according to the present invention is shown in  FIG. 1  of the accompanying drawings. The parlour  1  comprises a rotatable platform  3  having an annular shape and being provided with fifty milking stalls  5  arranged side by side circumferentially along the platform  3 . Since the parlour  1  is of a parallel rotary type, the stalls  5  are arranged so that a cow  7  to be milked stands in a stall  5  facing radially inwards towards the centre  9  of rotation of the platform  3 . In use, the platform  3  is rotated by suitable drive means in an anti-clockwise direction as indicated by arrow  11 . 
     With reference to  FIG. 1 , it will be understood that cows  7  to be milked congregate in a holding bay  19  and walk onto the platform  3  one by one at a stall entry point  20 . The entry point  20  comprises an animal walk way having a width substantially equal to that of a milking stall  5 . This width is sufficient for an animal, such as a cow, to comfortably walk through the walk way and into a stall  5 , but is not so great as to allow the passage of two animals side-by-side. In this way, animals are prevented from entering stalls  5  of the platform  3  simultaneously. It will be understood that the speed of rotation of the platform  3  is sufficiently low for a cow  7  to step onto the platform  3  and walk into a passing stall  5 . It will also be understood that, once a cow  7  has entered a stall  5 , further rotation of the platform  3  closes the stall  5  so as to prevent the cow  7  from backing out of the stall  5 . Each stall  5  is provided with four teat cups connected to a conventional milking system by means of hoses. As will be explained in more detail below with reference to  FIGS. 2 and 3 , these teat cups  21   a ,  21   b ,  21   c ,  21   d  are automatically attached to the teats  23   a ,  23   b ,  23   c ,  23   d  of a cow by means of one of two robot arms  100 ,  200  which are moved by an electronic control system. Once the teat cups  21  are attached to the teats  23 , the cow  7  is milked in a conventional fashion whilst the platform  3  continues to rotate. Once milking has been completed, the teat cups  21  are removed from the teats  23  by means of an automatic teat cup retraction system (not shown) which pulls on the hose  20  associated with each teat cup  21  and withdraws the teat cups  21  back into a teat cup magazine  27 . 
     Each stall  5  is provided with a teat cup magazine  27  which comprises four recesses into which the four teat cups  23  locate when not in use. Each magazine  27  is located adjacent the entrance of the associated stall  5  so as to not unduly hinder access by a cow  7  to the stall  5  and so as to be positioned adjacent the rear of a cow  7  stood in the stall. The magazine  27  will therefore be understood to hold the teat cups  21  in a known storage position which is readily accessed by the robot arm  25  and which is sufficiently close to the teats  23  of the cow  7  to allow ready movement of the teat cups  21  to the teats  23  from the magazine  27 . 
     Once the teat cups  21  have been retracted into the teat cup magazine  27 , the milking stall  5  in which the cow  7  is located will shortly thereafter move to a stall exit point  29  (see  FIG. 1 ). At the exit point  29 , a stall  5  is arranged in an open configuration so that a cow  7  located therein may back out of the stall  5  and leave the parlour  1  by means of an exit walkway  31 . 
     As mentioned above, the rotary parlour  1  of the present invention is provided with an automated system for attaching teat cups  21  to the teats  23  of a cow  7  to be milked. This automated system comprises two robot arms  100 ,  200  and an electronic control system. The electronic control system allows movement of the robot arms  100 ,  200  to be coordinated with the rotary movement of the platform  3 . Suitable means for monitoring the rotary speed and position and the direction of rotation of the platform  3  is provided (not shown) and this information is used by the control system in order to ensure accuracy in coordinating the movements between the robot arms  100 ,  200  and associated stalls  5 . 
     In  FIGS. 2 and 3  of the accompanying drawings, six milking stalls (numbered S 15 , S 16 , S 17 , S 18 , S 19  and S 20 ) are shown moving past the robot arms  100 ,  200 . Alternative arrangements of robot arm may be provided and the schematic example shown in  FIGS. 2 and 3  is provided merely for the purposes of illustrating the operation of the present invention. Specifically, each robot arm  100 ,  200  shown in  FIGS. 2 and 3  comprises first, second and third arms  50 ,  52 ,  54  rotatably connected to one another by elbow joints  56 ,  58 . Each robot arm  100 ,  200  further comprises teat cup carrying means. In the present embodiment, the teat cup carrying means is a teat cup gripper  60  pivotably connected to the third arm  54  at a wrist joint  62 . However, in a particularly preferred alternative embodiment (not shown), a robot arm  100 ,  200  is provided with means for carrying two or more teat cups simultaneously. This carrying means may comprise an element having four recesses into each of which a teat cup may be received. Each robot arm  100 ,  200  also comprises a swivel unit  64  from which the first arm  50  extends. The first arm  60  is rotatable about a central axis  66  by means of the swivel unit  64 . 
     The swivel units  64  of each robot arm  100 ,  200  are circumferentially spaced from one another by a distance equal to the width of a milking stall  5 . Accordingly, it will be understood that the two robot arms  100 ,  200  operate to simultaneously service neighbouring stalls  5  of the platform  3 . As shown in  FIGS. 2 and 3 , each robot arm  100 ,  200  services a stall in the same way by moving teat cups  21  in turn from a magazine  27  into attachment with the teats  23  of a cow  7 . 
     In this regard, once a teat cup magazine  27  moves within reach of a gripper  39 , the associated robot arm  100 ,  200  grasps a first teat cup  21   a  and moves said teat cup to an estimated position of a first teat  23   a . The precise position of the first teat  23   a  is then determined in a conventional manner using an appropriate sensing device. Once the teat  23   a  has been accurately located, the robot arm  100 ,  200  then attaches the teat cup  21   a  to the teat  23   a . This process is then repeated for the remaining three teat cups  21   b ,  21   c ,  21   d  in turn as the stall  5  continues to rotate on the platform  3 . 
     It will be understood that the provision of the two robot arms  100 ,  200  means that each robot arm only needs to service every other milking stall  5 . As such, each robot arm  100 ,  200  has additional time in which to complete a servicing activity. 
     The additional time for servicing a milking stall is dependent upon the working/operating range of the robot arm  100 ,  200 . It will be appreciated that, in a conventional milking parlour having a robot arm, the robot arm is extendable so as to be capable of servicing no more than the milking stall positioned in its immediate vicinity. In other words, in a conventional milking parlour, a robot arm would be able to service the milking stall immediately adjacent the robot arm, but would not be able to extend a sufficient distance to service a neighbouring milking stall. In contrast, and with reference to  FIG. 2  in particular, the milking shown in the accompanying drawings includes robot arms  100 ,  200  which extend sufficiently to service not only a milking stall located immediately in front of said arm, but also the two milking stalls located on either side of said stall. Specifically, it will be appreciated that the milking stall numbered S 16  is positioned immediately adjacent the first robot arm  100 . The swivel unit  64  of the first robot arm  100  is located on an extended centre line of the milking stall numbered S 16  (i.e. an imaginary radial line positioned midway between the radial side walls of the stall). With the first robot arm  100  and platform  3  in this relative position as shown in  FIG. 2 , the working/operating range of the first robot arm  100  is sufficient to allow said arm to service a milking stall as it moves from the position of the milking stall numbered S 15  in  FIG. 2  to the position of the milking stall numbered S 16 . Indeed, the first robot arm  100  is extendable so as to continue to service a milking stall as it moves beyond the position of the milking stall numbered S 16  in the direction of arrow  11  as shown in  FIG. 2 . It will be appreciated that the first robot arm  100  has a working/operating range spanning the width of three milking stalls (numbered S 15 , S 16  and S 17  in  FIG. 2 ). 
     With regard to  FIG. 2 , it will be seen that the second robot arm  200  begins servicing the milking stall numbered S 16  when this stall has moved approximately half way past the first robot arm  100 . At this time, the first robot arm  100  simultaneously begins servicing the milking stall numbered S 15  neighbouring the milking stall numbered S 16 . It will be understood that the next stall to be serviced by the second robot arm  200  is the stall numbered S 14  and the second robot arm  200  does not need to begin servicing this next stall until that stall has moved half way past the first robot arm  100 . Each robot arm  100 ,  200  therefore has an extended period of time in which to service a stall  5  as a consequence of there being two robot arms. As shown in  FIG. 3 , the robot arms  100 ,  200  have completed servicing their respective milking stalls  5  by the time the next stalls to be serviced have moved within reach. As will be seen with reference to  FIG. 3 , the stall numbered S 14  has moved half way past the first robot arm  100  and will shortly be serviced by the second robot arm  200 . 
     It will be appreciated that, in servicing stalls simultaneously, the robot arms  100 ,  200  may theoretically undertake the same actions at the same time. In other words, both robot arms  100 ,  200  may, for example, attach their respective second teat cups  21   b  to a teat in the same moment. However, in practice, the robot arms are likely to be delayed to differing extents (typically because of animal movements) so that, although different stalls are simultaneously serviced, the robot arms  100 ,  200  undertake different actions at any given time. Indeed, it is to be emphasised that a first robot arm may be delayed to such an extent that the other robot arm begins servicing its next stall before the first robot arm has completed its servicing tasks and is also able to move to its next stall. For example, the robot arms  100 ,  200  in  FIG. 3  are illustrated as attaching their respective fourth teat cups to a teat at the same time, however in practice it will be appreciated that the first robotic arm  100  may well have encountered fewer delays in its teat cup attachment than the second robot arm  200  and would therefore have already begun servicing its next milking stall numbered S 13 . Accordingly, the two robot arms  100 ,  200  would then be simultaneously servicing milking stalls numbered S 13  and S 16 . 
     It will therefore be appreciated that the robot arms  100 ,  200  operate entirely independently of one another in that one robot arm does not reduce its rate of teat cup attachment in order to keep pace with a delayed robot arm. Nevertheless, the control system coordinates the movement of the robot arms  100 ,  200  so as to ensure the robot arms  100 ,  200  do not collide with one another. It will be appreciated that the risk of a collision is comparatively high when the stalls being serviced require the robot arms  100 ,  200  to cross one another. For example, the second robot arm  200  in  FIG. 3  may well, in practice, experience fewer delays in teat cup attachment than the first robot arm  100  and therefore be able to begin servicing its next stall (the milking stall numbered S 14 ) before the first robot arm  100  has completed its servicing of the milking stall numbered S 15 . In these circumstances, the two robot arms  100 ,  200  will cross one another in simultaneously servicing the milking stalls numbered S 14  and S 15 . The electronic control system and method used to avoid collision of the two robots  100 ,  200  is described in greater detail below. 
     In a further embodiment, the electronic control system may be adapted to allow a robot arm  100 ,  200  to service the same milking stall as the other robot arm  100 ,  200 . A robot arm may operate in this way temporarily, for a short period of time, in circumstances where said robot arm has suffered very few delays in its teat cup attachment and as a result has a surplus of time in which to assist a further robot arm which has been delayed in its teat cup attachment. Such a coordinated servicing of the same milking stall may obviate the need to reduce platform rotation speed. Once the assistance has been provided by a particular robot arm, that robot arm then reverts to servicing its own milking stalls. 
     The robot arms  100 ,  200  may be provided with one or more proximity sensors which detect when the robot arm is in close proximity to, for example, the leg of a cow  7  or an item of milking equipment. 
     Also, although only schematic robot aims  100 ,  200  have been described above for the sake of simplicity, prior robots used in the milking industry have up to six axes of movement and is envisaged that similar robots would be used in practice in the milking parlours described herein. 
     Furthermore, a robot arm having seven axes of movement may be used in the place of the schematic robot arms  100 ,  200  specifically described above. Such a robot arm has one axis of movement in addition to the six axes of movement conventionally found in a milking robot, and this additional axis of movement is of particular assistance in avoiding the legs of a cow and/or milking equipment (as detected by a proximity sensor on the robot arm). The additional axis of movement is of particular use where two robots are employed since the additional flexibility of movement provided by the additional axis allows the two robot arms to more readily avoid one another and generally move in a coordinated fashion. 
     It will also be understood that either one or both of the two robot arms  100 ,  200  shown in  FIGS. 2 and 3  may be supported on a base moveable in the direction of arrow  11 , for example, on a telescopically extendable element. In this way, the robot arms  100 ,  200  of  FIGS. 2 and 3  may be moved in the general rotary direction of the platform  3  so as to provide additional time, if required, in order to complete a servicing activity. 
     In this latter regard, the swivel unit  64  of each robot arm  100 ,  200  may be mounted on a telescopically extendable element  34 , shown in  FIG. 4 , which itself is mounted to the parlour floor by means of a base unit  32 . It will be understood that the platform  3  rotates past each base unit  32  which remains in a fixed location in the parlour  1 . Each extendable element  34  is telescopically extendable in a generally tangential direction relative to the platform  3 . Each robot arm  100 ,  200  may be thereby moved along a part circular path with the platform  3  so that the position of the robot arm  100 ,  200  relative to a particular milking stall  5  may be maintained through a predetermined angle of platform rotation. It will be understood that this angle is, in part, determined by the extent to which the telescopic element may be extended. Furthermore, in order to assist in maintaining a constant relative position between each robot arm  100 ,  200  (specifically, the swivel unit  64 ) and the associated stall  5 , the relevant base unit  32  may be rotatable so as to allow the extendable element  34  to rotate in a plane parallel with the parlour floor. 
     In the embodiments described above wherein robot arms are positioned so as to operate in close proximity to one another, it will be understood that a common volume will exist which is within the working/operating range of each robot aim such that a collision between the arms is possible. This common volume is considered by the electronic control system as a plurality of sub-volumes (for example, a matrix of sub-volumes). If a robot arm is moved to locate in one or more of these sub-volumes, then the control system will ensure that the other robot arm is moved in such a way so as to not be located in these sub-volumes. In this way, more than one robot arm is prevented from being located in a given sub-volume at the same time. In order to ensure adequate clearance between robot arms, the electronic control system may prevent a robot arm from moving into a sub-volume adjacent a sub-volume occupied by another robot arm. 
     It will be understood that each robot arm may send electronic signals conferring information regarding its activity. This information typically relates to the progress being made in completing a servicing task. The communication of this information may be made by a robot arm to a central electronic control system, which controls movement of several robot arms as described above. Alternatively, this information may be sent from a robot arm directly to one or more other robot arms so that each of these other robot arms may individually modify their own activity as deemed necessary in view of the received information. For example, the information transmitted by a robot arm may relate to the current position of that arm. On receiving such information from a neighbouring robot arm, a further robot arm may determine that its own movement should be modified in order to avoid a collision with the neighbouring robot arm. 
     The present invention is not limited to the specific embodiments described above. Alternative arrangements will be apparent to a reader skilled in the art. For example, the teat cup carrying means may be capable of carrying more than one teat cup (for instance, four teat cups) simultaneously, whilst being capable of picking-up and/or attaching/putting down teat cups individually (i.e. one at a time). In this way, the number of movements made by a robot arm from the teat cup magazine to the animal is reduced from four (when the teat cups are picked-up and moved individually) to one (when the teat cups are all moved together from the magazine to the animal together). The teat cup carrying means may be provided with a plurality (e.g. four) teat cup receivers for receiving a teat cup. Each receiver may be a gripper or may comprise an electro-magnet operable independently of electro-magnets associated with other receivers.