Distribution system and method for distributing carriers

1 . A distribution system comprising:

a transport plane comprising logical positions;

carriers for transporting objects;

a drive system to move the carriers on the transport plane between logical positions, the movements of the carriers relative to the logical positions of the transport plane generating surface wear of the logical positions as a result of friction between the carriers and the transport plane;

the movements of the carriers comprising starting, moving over, or stopping of carriers relative to the logical positions; and

a control system controlling the carriers to move on planned routes from start logical positions to final destination logical positions on the transport plane via intermediate logical positions,

wherein the control system comprises a routing system calculating the planned routes for each of at least two carriers on the transport plane by modeling the transport plane with graphs of nodes,

wherein the routing system calculates each planned route based on a balancing of the surface wear of the transport plane using at least one of temporal blocking of logical positions, variable move length, and variable reservation length, and

wherein the balancing of the surface wear of a logical position takes into account the amount of surface wear caused each time a carrier starts to move from the logical position (“start wear”), each time a carrier moves over the logical position (“move wear”), and each time a carrier stops on the logical position of the transport plane (“stop wear”), the “total wear” of a logical position comprising the total of the start wear, the move wear and the stop wear for that logical position.

2 . The distribution system according to claim 1 , wherein the calculation of the routes comprises determining shortest paths for the carriers across the transport plane from the start position to the final destination position.

3 . The distribution system according to claim 1 , wherein the routing system is configured for defining at least two patterns of blocked logical positions, wherein one of the patterns forces the routing system calculating first routes for the carriers and another one of the patterns forces the routing system calculating second routes for the carriers different from the first routes.

4 . The distribution system according to claim 3 , wherein the routing system is configured for switching from one pattern to another pattern after a predefined time and/or based on the number of carriers moved over a certain area of the transport plane.

5 . The distribution system according to claim 4 , wherein the control system is configured for measuring the number of carriers which have been using the certain area of the transport plane since the last switch, wherein the routing system is configured for switching to another pattern if a defined threshold has been reached.

6 . The distribution system according to claim 3 , wherein the patterns comprise at least one low traffic pattern having a first number of blocked logical positions and at least one high traffic pattern with a second number of blocked logical positions, wherein the second number is reduced in comparison to the first number.

7 . The distribution system according to claim 1 , wherein the blocked logical positions are arranged to block the number of different options for carriers to move.

8 . The distribution system according to claim 1 , wherein the routing system is configured for using variable move lengths for one or more of: a selection of moves, a certain number of carriers, a certain time period, and defined areas of the transport plane.

9 . The distribution system according to claim 8 , wherein the routing system is configured for varying only the length of a first move of the carriers.

10 . The distribution system according to claim 8 , wherein the routing system is configured for varying the move lengths for each move of a carrier along a route.

11 . The distribution system according to claim 9 , wherein the control system is configured for measuring the number of carriers which have been using a logical position, wherein the routing system is configured for comparing the measured number of carriers of neighboring logical positions with a defined threshold and to adapt the move length depending on the comparison.

12 . The distribution system according to claim 9 , wherein the control system is configured for measuring the number of carriers which have been using a logical position, wherein the routing system is configured for using the measured number as weight factor for optimizing the move length, wherein the routing system is configured to prioritize using logical positions with low weight.

13 . The distribution system according to claim 1 , wherein the routing system is configured for using a variable reservation length for all or a selection of moves in a defined area of the transport plane, wherein the routing system is configured for reducing a maximum reservation length for all or a selection of moves in a defined area of the transport plane and/or for increasing a minimum reservation length for all or a selection of moves in a defined area of the transport plane.

14 . The distribution system according to claim 1 , wherein the control system comprises at least one executing unit configured for executing the planned routes for transporting the carriers from their respective start position to their respective final position.

15 . A method for distributing carriers using a distribution system according to claim 1 , wherein the method comprises moving the carriers on the transport plane of the distribution system between logical positions by using the drive system,

wherein the method comprises controlling the carriers to move on a planned route from the start position to the final destination position on the transport plane via intermediate logical positions by using the control system,

wherein the method comprises calculating the planned route for at least two carriers on the transport plane by modeling the transport plane with graphs of nodes by using the routing system,

wherein the calculating comprises balancing of surface wear of the transport plane, and

wherein the calculating comprises using temporal blocking of logical positions and/or a variable move length and/or a variable reservation length.

16 . The distribution system of claim 1 comprising the routing system balancing surface wear using temporal blocking of logical positions, variable move length, and variable reservation length.

17 . The distribution system of claim 15 in which a planned route utilizes a series of logical positions, and the balancing takes into account the surface wear for each of the series of logical positions.

18 . The distribution system of claim 1 , wherein the method further comprises determining for each logical position the amount of surface wear caused by carriers starting, moving over or stopping at the logical position during a period of time.

19 . The distribution system of claim 18 , wherein the balancing of surface wear of a logical position takes into account the number of starts, move overs and stops of carriers at each logical position.

20 . The distribution system of claim 19 , wherein the number of starts, move overs and stops are determined for a specified time period.

21 . The distribution system of claim 20 wherein the balancing of surface wear comprises determining the total wear of each logical position.

22 . The distribution system of claim 21 , wherein the determining of the total wear comprises determining the start wear, the move over wear and the stop wear of each logical position.

23 . The distribution system of claim 22 , wherein determining the start wear, the move over wear and the stop wear of each logical position is based on the number of starts, move overs and stops of carriers at the logical position.

24 . The distribution system of claim 23 , wherein the start wear, the move over wear and the stop wear are determined for a specified time period.

25 . The distribution system of claim 23 , wherein the start wear, the move over wear and the stop wear are determined in absolute terms.

26 . The distribution system of claim 19 , wherein the balancing of surface wear comprises the routing system calculating planned routes to equalize the total surface wear of the logical positions.

27 . The distribution system of claim 1 , wherein the distribution system comprises at least a first logical position and at least a second logical position.

28 . The distribution system of claim 27 , wherein the balancing of surface wear takes into account the total wear of each of the at least a first logical position and the at least a second logical position.

29 . The distribution system of claim 28 , wherein the balancing of surface wear comprises comparing the total wear of the at least a first logical position with the total wear of the at least a second logical position.

30 . The distribution system of claim 29 , wherein the balancing of surface wear comprises the routing system calculating planned routes to equalize the total surface wear of the at least a first logical position and the total surface wear of the at least a second logical position.

31 . The method of claim 15 , wherein the determining comprises counting the number of starts, move overs and stops for each logical position.

32 . The method of claim 31 , wherein determining the total wear of each logical position comprises totaling the start wear, the move over wear, and the stop wear of each logical position.

33 . The method of claim 32 , wherein the balancing of surface wear comprises the routing system calculating planned routes to equalize the total surface wear of the logical positions.