Method of determining a handover position and laboratory automation system

1. A method of determining a handover position of a gripping device, wherein the gripping device is assigned to a laboratory sample distribution system having a transport plane and a plurality of electro-magnetic actuators positioned below the transport plane and wherein the handover position is assigned to a handover electro-magnetic actuator, the method comprising:

grabbing, by the gripping device, a position determining device such that the position determining device is held fixedly by the gripping device, wherein the position determining device comprises a magnetically active device;

positioning the position determining device, while being held by the gripping device, on the transport plane;

activating the handover electro-magnetic actuator such that it generates a magnetic field interacting with a magnetic field generated by the magnetically active device such that an attractive force is applied on the position determining device;

moving the position determining device, while being held by the gripping device, by the attractive force to a first position;

detecting the first position; and

determining the handover position based at least in part on the first position.

2. The method according to claim 1 , wherein the handover position is determined as being identical to the first position.

3. The method according to claim 1 , wherein determining the handover position comprises,

moving the position determining device, by the gripping device, on the transport plane in each of a group of directions for a given amount of displacement, every time starting from the first position, to a respective intermediate position;

after each step of moving in a direction, moving the position determining device while being held by the gripping device to a respective further position by the attractive force;

detecting each respective further position; and

determining the handover position based at least in part on the respective further positions.

4. The method according to claim 3 , wherein the group of directions comprises two, three or four directions.

5. The method according to claim 3 , wherein all directions contained in the group of directions are arranged with equal angle between each two circularly neighboring directions.

6. The method according to claim 3 , wherein the given amount of displacement is less than 10 mm.

7. The method according to claim 3 , wherein the given amount of displacement is less than 5 mm.

8. The method according to claim 3 , wherein the given amount of displacement is less than 3 mm.

9. The method according to claim 3 , wherein the handover position is determined as a center of a polygon defined by the further positions.

10. The method according to claim 3 , wherein the handover electro-magnetic actuator is deactivated before each step of moving the position determining device in one of the directions and is reactivated after that step.

11. The method according to claim 3 , wherein the first position and/or the further positions are represented by planar coordinates on the transport plane after being detected.

12. The method according to claim 1 , wherein positioning, by the gripping device, the position determining device on the transport plane is performed such that the gripping device is positioned over or besides the handover electro-magnetic actuator.

13. The method according to claim 1 , wherein positioning the position determining device, while being held by the gripping device, on the transport plane is performed manually.

14. The method according to claim 1 , wherein electro-magnetic actuators surrounding the handover electro-magnetic actuator are activated such that they generate respective magnetic fields interacting with the magnetic field generated by the magnetically active device such that a repulsive force is applied on the position determining device at least during each step of moving the position determining device by the attractive force.

15. The method according to claim 1 , wherein the position determining device comprises a number of rolls or ball-bearings for contacting the transport plane.

16. A laboratory automation system, the laboratory automation system comprising: a plurality of analyzing stations;

a number of gripping devices;

a position determining device fixedly held by at last one of the number of gripping devices;

a laboratory sample distribution system comprising

a number of sample container carriers configured to carry one or more sample containers, each sample container carrier comprising at least one magnetically active device,

a transport plane configured to support the sample container carriers,

a number of electro-magnetic actuators stationary arranged below the transport plane, the electro-magnetic actuators configured to move a sample container carrier on top of the transport plane by applying a magnetic force to the sample container carrier, and

a control device configured to control the movement of the sample container carriers on top of the transport plane by driving the electro-magnetic actuators such that the sample container carriers move along corresponding transport paths, wherein for each gripping device, a handover electro-magnetic actuator is assigned out of the number of electro-magnetic actuators, wherein a sample container is to be handed over to or from the gripping device while a sample container carrier carrying the respective sample container is positioned above the handover electro-magnetic actuator; and

a process control unit, wherein the process control unit is configured to control the gripping devices and the laboratory sample distribution system such that a method according to claim 1 is performed.

17. The laboratory automation system according to claim 16 , wherein the magnetically active device of the position determining device generates a stronger magnetic field than each of the magnetically active devices of the sample container carriers.