A method of operating an arrangement for cleaning an end effector (21) of a robotic manipulation device (9a, 9b, 9c) of a parallel rotary parlor having a platform (2) with milking stalls for holding animals standing in a radial direction on the platform, the method comprising the steps of:
- with a control unit (11), automatically controlling an arm mechanism of the robotic manipulation device located radially outside an outer edge portion (2b) of the platform (2), the arm mechanism including connected link elements terminating with a last link element, the link elements being connected to each other via joints allowing movements of the link elements around pivotal axes so that the link elements and the pivot joints of the arm mechanism move with respect to each other, movement of the link elements being controlled by the control unit;
- with the control unit (11), automatically controlling the end effector (21) to move from an initial position outside of the platform (2), via a space between rear legs of an animal standing in one of the stalls, to a position with the tool (24) being located below teats of the animal to perform a task in relation to a milking process of the animal (1) in a milking stall (3), the end effector (21) including an inner end portion (21b) and a free end portion (21a), the inner end portion (21b) being attached to the last link element of the arm mechanism such that the end effector (21) forms an outer end of the arm mechanism, the end effector (21) having an elongated shape with a longitudinal axis (22) extending in a direction from the inner end portion (21b) to the free end portion (21a), wherein at the free end portion (21b), the end effector (21) comprises a tool (24) that, under the control of the control unit, performs the task in relation to the milking process of an animal (1) in a milking stall (3);
- with the control unit (11), automatically controlling an end effector cleaning station (18) to provide at least one liquid jet, the end effector cleaning station (18) being mounted within a working area of the robotic manipulation device (9a, 9b, 9c) radially outside the radial edge portion (2b) of the platform, and comprising a spray device (26) that, under the control of the control unit (11), provides the at least one liquid jet;
- and
- at a time to clean the end effector (21), having the control unit (11) activate the robotic manipulation device (9a, 9b, 9c) such that the link elements and the pivot joints of the arm mechanism move with respect to each other to pivot and move the end effector (21) downwards from a first position above the end effector cleaning station (18) to a lower, second position where the tool (24) of the end effector (21) is positioned to be hit by the liquid jet during a cleaning operation of the end effector (21), wherein during said movement into the second position, the longitudinal axis (22) of end effector (21) is vertically oriented, and with the end effector (21) in the second position controlling the end effector cleaning station (18) to provide the liquid jet directed at the tool (24) of the end effector (21) such that liquid from said liquid jet that hits the end effector flows downwardly along the end effector in the direction from the inner end portion (21b) to the free end portion (21a).