a milking system or milking station 1 for voluntary milking comprising cleaning means in accordance with the invention is illustrated in fig1 . an automatic milking machine ( not illustrated in detail ) is provided for milking animals , such as for example cows . the automatic milking machine comprises teat cups 2 connected to an end unit by means of milk lines ( only small portions of which attached to the teat cups are shown in the figure ). a milking robot or other automatic handling device 3 having a handling device , such as a robot arm 4 , equipped with a gripper device 5 in its far end is provided for automatically fetching the teat cups 2 of the milking machine from a rack 6 , in which the teat cups 2 are stored . the robot arm 4 moves the teat cups 2 toward the udder of the cow and attaches them to the teats of the cow . the teat cups 2 may be fetched , moved and attached one at a time or several at a time . the milking robot 3 is typically equipped with a camera system or other detecting device 7 for determining the exact positions of the teats to which the teat cups 2 are to be attached . the gripper device 5 is intended to grip , to hold and to release the teat cups 2 or other equipment , such as for example a teat - cleaning cup 11 . the milking station 1 may comprise other conventionally used devices , not shown or described in detail herein . for example , teat - treatment devices may be provided , identification members for identifying a cow etc . the milking station 1 further comprises a control unit 8 , which is responsible for controlling the milking station 1 . processing within the control unit 8 comprise , inter alia , initiation of various activities in connection with the milking such as opening and closing of gates , controlling of the automatic milking machine and the milking robot 3 . the control unit 8 typically comprise a microcomputer , suitable software and a database including information of each of the cows being milked by the automatic milking machine , such as for example when a specific cow was last milked or last fed , or her milk production , her health etc . in accordance with the invention , means are provided for enabling efficient cleaning of the gripper device 5 . in one embodiment of the invention , the means comprise a cleaning device 9 having a suitable cleaning member 10 . the cleaning member 10 may for example comprise spray means for spraying cleaning agents on the gripper device 5 , or blowing means for blowing air , preferably compressed air , onto the gripper device 5 and thereby cleaning it . other types of cleaning members are conceivable as well . in a particular embodiment the cleaning member 10 is a sponge or the like . the cleaning is then effectuated by removing dirt off the gripper device 5 by rubbing it against the sponge . the cleaning member 10 of the cleaning device 9 is then a suitable sponge . the use of a sponge provides a cost - efficient solution , with low energy consumption and low purchase costs . further , the sponge is easily replaced when need arises . the robot arm 4 comprising the gripper device 5 is moved towards the cleaning device 9 upon initiation of a gripper device cleaning procedure . the gripper device 5 of the robot arm 4 is thereby moved to a cleaning position ( indicated by dashed lines in the figure ) in which the cleaning can be performed . in case the cleaning member 10 is a sponge , the robot arm 4 is preferably arranged to move back and forth in front of the sponge a number of times in order to rub the gripper device 5 against it . upon finishing the cleaning of the gripper device 5 , the robot arm 4 is returned to a non - active or an idle position . the robot arm 4 is then ready for a subsequent operation , such as fetching teat cups 2 or the like . for ease of illustration , the cleaning device 9 is shown as a separate unit in the figure . however , the cleaning device 9 is preferably integrated with the milking station 1 in any suitable manner , for example constituting part of or being arranged on the enclosure of the milking station 1 . the cleaning device may be arranged on a part of the milking robot 3 . the only requirement is that the cleaning device 9 is placed so as to be within reach of the gripper device 5 of the robot arm 4 . the control unit 8 comprises software for effectuating the cleaning procedure in accordance with the invention . the cleaning procedure for cleaning the gripper device 5 may be programmed and customized to suit the needs of the specific farm in which it is utilized . the cleaning may , for example , be performed after each cow that has been milked , after every fifth or tenth milked cow , a certain number of times an hour or whatever frequency is most appropriate for the particular milking farm . the frequency may depend on various factors , such as the number of cows ( the environment may be more soiled the more cows are being kept ), the water quality , the sensitivity of the gripper device and so on . the frequency with which to cleanse the gripper device 5 can be set by the user and is easily changed should such need arise . the suitable cleaning frequency is programmed into the control unit 8 . there are means for transmitting signals from the control unit 8 to the milking robot 3 , for initiation of the gripper device cleaning procedure . that is , the control unit 8 comprises means , such as software , for initiating the gripper device cleaning procedure . however , the gripper device 5 may comprise means for transmitting signals to the control unit 8 as well . for example , the gripper device 5 may include sensing means for sensing if the surface of the gripper device 5 is too soiled to function properly and transmit an indication to the control unit 8 about this . such sensing of a soiled surface may be implemented by means of a camera and a laser source emitting laser light . the detecting device 7 described earlier may be utilised in this sensing of a soiled surface . the camera is provided to register laser light as reflected from the gripper device 5 and to thereby enable a determination of whether the surface of the gripper device 5 is soiled . the gripper device 5 may comprise an optical sensor for this end , which optical sensor presumably is as soiled as the gripper device surface in which it is arranged . alternatively , inductive sensors may be provided in the gripper device 5 for sensing a magnetic field or an inductance or a change thereof as caused by the gripper device surface being soiled . a video camera or ccd - camera may be utilised for the above sensing of a soiled surface . such camera may be fixedly arranged to take images of the gripper device 5 in the idle position , and the control unit 8 may then comprise means for processing the images or evaluating the need of cleansing in dependence on the amount of reflected light . the cleaning may also be initiated if the gripper device 5 fails to grip hold of a teat cup . sensing means for sensing such failure is then included within the gripper device 5 . such sensing means are disclosed in a patent application entitled “ detecting arrangement and method for a magnetic gripper device ”, filed on sep . 2 , 2005 , assigned to the same applicant as the present application . the control unit 8 may be programmed to initiate the cleaning procedure of the gripper device 5 in case of such teat attachment failure . further , the sensing means may also detect if the performance of the gripper device 5 is deteriorating , that is , the gripper device 5 may still be capable of holding a teat cup 2 but the grip is deteriorating . the gripper device 5 is then cleaned before a failure occurs . typically , when a teat attachment step fails , the control unit 8 of the milking machine starts a fault - localizing test . such fault - localizing tests require rather long periods of time in order to be performed , typically about 10 - 15 minutes , during which no milking can be done . in contrast , the cleaning step in accordance with the invention may be accomplished within about 5 - 10 s . therefore , should the teat attachment procedure fail , cleaning of the gripper device 5 is a fast way to eliminate the possibility of the gripper device 5 being too dirty as the cause to the failure , or a fast way to obtain a successful teat attachment in case the reason for the failure is indeed that the gripper device 5 is too dirty . the detecting device 7 , for example a camera , for determining the exact positions of the teats may need cleaning as well . the detecting device 7 is preferably cleansed regularly in order to not reduce its performance . the cleaning of the detecting device 7 may , for example , be performed by moving the robot arm 4 comprising the detecting device 7 to a cleaning position . in an embodiment of the invention , the same cleaning device is utilised for cleaning the gripper device 5 . since the cleaning of the gripper device 5 is performed in a similar manner or even by utilising the same cleaning means as is used for cleaning the detecting device 7 , a most cost - efficient cleaning of gripper devices is provided . in an embodiment of the invention , the cleaning of the gripper device 5 is performed each time cleaning of the detecting device 7 is effectuated . in particular , the cleaning device 9 may be adapted to accomplish simultaneous cleaning of the detecting device 7 and the gripper device 5 . the cleaning device 9 may comprise different cleaning members for the gripper device 5 and the detecting device 7 , respectively . the different cleaning members may then be arranged so as to allow simultaneous cleaning to be performed . the invention is also related to a corresponding method , illustrated in fig2 . the method 20 for cleaning the gripping device 5 arranged on the robot arm 4 of the milking station 1 is initiated in step 21 . the initiation may be triggered , for example , at completion of a milking occasion or at a detected failure to grip the teat cup 2 as described above . the initiation may be triggered by other means as well . in step 22 the robot arm 4 comprising the gripper device 5 is moved to a cleaning position . in the cleaning position , the robot arm 4 is in close proximity of the cleaning device 9 comprising the cleaning member 10 . finally , in step 23 , the cleaning of the gripper device 5 is carried out . the gripper device cleaning procedure may comprise any suitable ways of cleaning the gripper device 5 . for example , the gripper device cleaning procedure may comprise rubbing the gripper device 5 against a sponge , or spraying cleaning agents on the surface of the gripper device , or even a combination of the described different cleaning procedures . in the cleaning position , a detecting device 7 of the milking station 1 can also be cleaned . such step of cleaning the detecting device 7 can be effectuated before or after the cleaning of the gripper device 5 . upon completion of the gripper device cleaning procedure , the robot arm 4 may be moved to an idle position , in which the robot arm 4 is ready for a subsequent operation , such as a teat attachment procedure . the gripper device 5 is preferably an electromagnetic gripper device , but any other type of gripper device may benefit from the present invention . since electromagnetic gripper devices do not have any movable parts or open spaces wherein dirt may gather , they are particularly suitable for being cleansed by means of the invention . in the above description a milking station has been described in connection with an automatic milking system , and in particular a milking station for voluntary milking . however , the present invention may be utilised in other milking environments as well , for example in a not fully automated milking environment . for the purposes of the present invention , a milking station can be any area in which a milking animal is being milked , that is , an area arranged to house at least one animal for milking . the present invention can be implemented in any type of milking stall , for example a parallel stall arrangement or a rotary milking parlour . the term “ milking station ” is thus intended to encompass different types of milking stations . similarly , throughout the above description the term “ robot arm ” has been utilised . however , the term robot arm has been used in an illustrative embodiment of the invention , in which the term robot arm is generally used to denote a part of a milking robot . in the above description , the term “ robot arm ” could be exchanged to “ handling device ”. the handling device is intended to denote a handling device for handling teat cups and other milking related equipment . in accordance with the invention , such handling device may be the described robot arm of a milking robot , but it may alternatively be a supporting arm or service arm that can be moved in a computer - controlled manner , semi - manually or manually to a cleaning position . in summary , the present invention provides an efficient cleaning of gripper devices . the farmer is alleviated from the task of manually inspecting the gripper devices and wash them upon need . further , by regularly cleaning the gripper device the operation of the milking station is ensured and the gripper device provides at all times a firm and reliable grip of the teat cups . while the present invention has been described in various embodiments it shall be appreciated that the invention is not limited to the specific features and details set forth , but is defined only by the appended patent claims .
methods clean a gripping device of a milking station for milking animals . methods include initiating a gripper device cleaning procedure , moving the gripper device to a cleaning position , and carrying out the gripper device cleaning procedure . efficient and automatic cleaning of gripper devices is provided . milking systems also include apparatuses for cleaning a gripper device .