Method for sorting conveyed objects on a conveyor system using time control

Abstract

In a first step of a method for bundling conveying streams on a material handling element including a number of incoming conveyor segments, at least one coupling to an outgoing conveyor segment, on which the incoming conveyor segments converge, and a number of holding devices for holding a conveying stream on the incoming conveyor segments, target arrival times, at which the objects arrive as planned at a destination, are calculated for the conveyed objects. A conveyed object is released at a release time which substantially corresponds to the target arrival time minus the target pass-through time required for the conveyed object to be transported as planned from a current position to the destination. A material handling element carries out the method.

Claims

1. A method for merging conveying streams at a material handling element with a plurality of incoming conveyor segments, at least one coupling to an outgoing conveyor segment, to which the incoming conveyor segments are merged, and a plurality of retainers configured to stop a conveying stream on the incoming conveyor segments, comprising: calculating with a controller for conveyed objects target arrival time points when the conveyed objects are scheduled to arrive at a destination, calculating with the controller for a conveyed object of the conveyed objects waiting at a material handling element a target run-through time needed for transport of the conveyed object as scheduled from a current position to the destination and releasing the conveyed object at a release time point which corresponds essentially to the target arrival time point minus the target run-through time.

2. The method as claimed in claim 1, wherein the target arrival time points are calculated with the controller according to a sorting sequence of the conveyed objects.

3. The method as claimed in claim 1, wherein a first conveyed object with a first target arrival time point of the target arrival time points waiting at a material handling element is released after a second conveyed object with a second target arrival time point of the target arrival time points further in the future, if the target run-through time for the second conveyed object is longer than for the first conveyed object.

4. The method as claimed in claim 1, wherein a first conveyed object with a first target arrival time point of the target arrival time points waiting at a material handling element is released before a second conveyed object with a second target arrival time point of the target arrival time points further in the future, if the target run-through time for the second conveyed object is longer than for the first conveyed object and the first conveyed object thereby arrives at the destination before a third conveyed object with a third target arrival time point of the target arrival time points after the second target arrival time point of the second conveyed object.

5. The method as claimed in claim 1, wherein a plurality of conveyed objects arrive at an identical target arrival time point of the target arrival time points as scheduled at the destination.

6. The method as claimed in claim 1, wherein the at least one coupling for an outgoing conveyor segment of a first material handling element is connected directly or indirectly to the incoming conveyor segment of a second material handling element forming a conveyor system of material handling elements.

7. The method as claimed in claim 1, further comprising: generating with the controller a predefined sorting sequence for a plurality of the conveyed objects, calculating with the controller before removing the conveyed objects (17) from a storage a plurality of variants of the target arrival time points maintaining the predefined sorting sequence for the plurality of the conveyed objects and executing with the controller a particular variant of the plurality of variants which has a lowest occupancy time of a conveying system.

8. The method as claimed in claim 1, wherein a second conveyed object of the conveyed objects is conveyed into a buffer, a sequencer, an alternative route or a feedback route and is held in a position there, until the position has been passed by a first conveyed object of the conveyed objects preceding the second conveyed object in a sorting sequence, if holding the second conveyed object results in a reduction of occupancy time of a conveying system.

9. The method as claimed in claim 1, wherein the material handling element comprises a robot.

10. The method as claimed in claim 1, wherein conveyed objects are removed from a storage in an ordered manner with respect to a plurality of destinations and with respect to a sorting sequence for a destination of the destinations to be supplied.

11. The method as claimed in claim 1, wherein conveyed objects are removed from a storage in an ordered manner with respect to a sorting sequence for the destination to be supplied, but chaotically with respect to a plurality of the destinations.

12. The method as claimed in claim 1, wherein releases per unit of time are monitored by a superordinate controller and a particular retainer of the plurality of retainers is released, at which a conveyed object of the conveyed objects with a lowest target arrival time point of the target arrival time points is waiting, if a threshold is not met for the releases per unit of time.

13. The method as claimed in claim 1, wherein releases per unit of time to each destination of a plurality of destinations to be supplied are monitored by a superordinate controller and a particular retainer of the plurality of retainers is released, at which a conveyed object of the conveyed objects with a lowest target arrival time point of the target arrival time points of a respective destination of the plurality of destinations to be supplied is waiting, if a threshold is not met for the releases per unit of time assigned to the respective destination (23a . . . 23c).

14. The method as claimed in claim 6, wherein the first and the second material handling elements of the conveyor system have access to a common table of the target release time points.

15. The method as claimed in claim 6, wherein at least method steps, which are related to a decision about releasing a conveyed object apart from taking into account the target arrival time point/the target run-through time/the target release time point are performed independently of all other material handling elements and/or independently of a central controller.

16. The method as claimed in claim 6, wherein method steps are performed identically with respect to releasing a conveyed object of the conveyed objects in all material handling elements.

17. The method as claimed in claim 6, wherein the first and the second material handling elements of the conveyor system have access to a common table of the target arrival time points.

18. The method as claimed in claim 17, wherein the common table also contains the target run-through times.

19. The method as claimed in claim 6, wherein a second conveyed object (17), with a second target arrival time point of the target arrival points following a first conveyed object in a sorting sequence is conveyed into a buffer, a sequencer, an alternative route or a feedback route and is held in a position there until the position has been passed by the first conveyed object with a first target arrival time point of the target arrival points, if the first conveyed object has been subjected to an unscheduled delay on the conveying system and it is no longer possible to have the first target arrival time point before the second target arrival time point of the second conveyed object without using the buffer, the sequencer, the alternative route or the feedback route.

20. The method as claimed in claim 19, wherein the target arrival time points for the conveyed objects not yet arriving at the destination, are recalculated with the controller in consideration of the unscheduled delay.

21. The method as claimed in claim 20, further comprising: calculating with the controller a plurality of variants of target arrival time points maintaining a predefined sorting sequence for a plurality of conveyed objects not yet reaching the destination in consideration of the unscheduled delay and a particular variant of the plurality of variants is executed which has a lowest occupancy time of the conveyor system.

22. A conveyor system, comprising a plurality of material handling elements, a material handling element of the plurality of material handling elements comprising: a plurality of incoming conveyor segments, at least one coupling for an outgoing conveyor segment, to which the incoming conveyor segments are merged, a plurality of retainers configured to stop a flow on the incoming conveyor segments, a controller which is configured to release a conveyed object at a release time point essentially corresponding to a target arrival time point when the conveyed object arrives as scheduled at a target destination minus a target run-through time needed for transport of the conveyed object from a current position to the target destination, and wherein at least one coupling for an outgoing conveyor segment of one of the material handling elements is connected directly or indirectly to an incoming conveyor segment of another of the material handling elements.

23. The conveyor system as claimed in claim 22, wherein a program logic is designed to be identical with regard to the release of a conveyed object of the conveyed objects in all the material handling elements.

24. A material handling element merging conveying streams, comprising a plurality of incoming conveyor segments, at least one coupling for an outgoing conveyor segment, to which the incoming conveyor segments are merged, a plurality of retainers configured to stop a flow on the incoming conveyor segments, and a controller which is configured to release a conveyed object at a release time point corresponding to a target arrival time point when the conveyed object arrives as scheduled at a target destination, minus a target run-through time needed for transport of the conveyed object from a current position to the target destination.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of the invention the latter is explained in more detail with reference to the following figures.

(2) In a much simplified, schematic representation:

(3) FIG. 1 shows a first schematically represented example of a material handling element/node;

(4) FIG. 2 as FIG. 1, but with sensors/reading devices in the incoming conveyor segments;

(5) FIG. 3 shows a schematically depicted warehouse and storage and retrieval machine in perspective view;

(6) FIG. 4 shows the storage of FIG. 3 in front view;

(7) FIG. 5 shows a logical representation of the storage and retrieval machine of FIG. 3;

(8) FIG. 6 shows a logical representation of a storage and retrieval machine, which can receive several conveyed objects at the same time;

(9) FIG. 7 shows a storage with a lift connected to the latter and with autonomously driving conveyor vehicles;

(10) FIG. 8 shows a logical representation of the arrangement of FIG. 7;

(11) FIG. 9 as shown in FIG. 7, but with a paternoster instead of the lift;

(12) FIG. 10 shows a logical representation of the arrangement of FIG. 9;

(13) FIG. 11 shows an example of a slightly more complex conveyor system;

(14) FIG. 12 shows a further example of a slightly more complex conveyor system, but without feedback route and sorting stage;

(15) FIG. 13 similar to FIG. 12, but with additional alternative routes;

(16) FIG. 14 shows a path-time diagram for a first conveyed object;

(17) FIG. 15 shows a path-time diagram for an additional conveyed object;

(18) FIG. 16 shows a path-time diagram for another additional conveyed object;

(19) FIG. 17 shows a path-time diagram for conveyed objects with different speeds;

(20) FIG. 18 shows the physical arrangement of several conveyed objects at a first node at a first time point and their assigned target arrival time points;

(21) FIG. 19 as FIG. 18, but after conveying a conveyed object;

(22) FIG. 20 shows the physical arrangement of several conveyed objects at a second node at a second time point, and their assigned target arrival time points;

(23) FIG. 21 as FIG. 20, but after conveying a conveyed object;

(24) FIG. 22 shows the physical arrangement of several conveyed objects at a third node at a third time point and their assigned target arrival time points;

(25) FIG. 23 as FIG. 22, but after conveying the conveyed objects;

(26) FIG. 24 similar to FIG. 23, but with a sorting error;

(27) FIG. 25 shows the physical arrangement of several conveyed objects in a situation in which the conveyed object causing an error in a sorting sequence has been transported into an alternative route;

(28) FIG. 26 as FIG. 25, but after conveying several conveyed objects;

(29) FIG. 27 as FIG. 25, but after conveying all conveyed objects;

(30) FIG. 28 shows an example of a physical arrangement of a plurality of conveyed objects with partly the same serial number or target arrival time;

(31) FIG. 29 similar to FIG. 1, but with a controller operating according to a different sorting method and

(32) FIG. 30 similar to FIG. 11, but with material handling elements/nodes according to FIG. 19.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(33) First of all, it should be noted that in the variously described exemplary embodiments the same parts have been given the same reference numerals and the same component names, whereby the disclosures contained throughout the entire description can be applied to the same parts with the same reference numerals and same component names. Also details relating to position used in the description, such as e.g. top, bottom, side etc. relate to the currently described and represented figure and in case of a change in position should be adjusted to the new position. Furthermore, also individual features or combinations of features from the various exemplary embodiments shown and described can represent in themselves independent or inventive solutions.

(34) FIG. 1 shows a first example of a material handling element Ka for bundling conveying streams. The material handling element Ka comprises two incoming conveyor segments 1a, 1b, a coupling 2 for an outgoing conveyor segment 3, to which the incoming conveyor segments 1a, 1b are merged and a plurality of holding devices 4a, 4b for halting a flow on the incoming conveyor segments 1a, 1b. Due to the said merging the material handling element Ka can also be interpreted as a node. In addition, the material handling element Ka comprises a controller 5, which is connected on the output side to the said holding devices 4a, 4b. At one input 6 the controller 5 is optionally connected to a superordinate central controller, as shown in FIG. 1 by an input-side arrow.

(35) In the example shown in FIG. 1 only two incoming conveyor segments 1a, 1b are provided. Of course it is also possible that more than two incoming conveyor segments 1a, 1b are provided. It is also possible that unlike the representation of FIG. 1 more than one coupling 2 and more than one outgoing conveyor segment 3 are provided. It is also possible that the controller comprises additional inputs for processing signals of further controllers, in particular of further controllers 5 of further nodes K.

(36) It should also be mentioned at this point that FIG. 1 is simply a symbolic representation of the material handling element Ka. For example, the holding devices 4a, 4b are shown as valves. Of course, this should not be considered to be restrictive but any elements for halting a conveying stream can be used as holding devices 4a, 4b. For example this can include barriers or gates which can be pushed or inserted into the conveying stream. A holding device 4a, 4b can also consist of conveyor belts, conveyor chains, conveyor rollers and the like, which can be halted. As said conveying means are generally used both for conveying and also for halting conveyed objects 17, in this case it is difficult or impossible to make a clear distinction between the holding devices 4a, 4b and the incoming conveyor segments 1a, 1b. The incoming conveyor segment 1a, 1b therefore has a double function in this case.

(37) It is also possible thatunlike the representation of FIG. 1a holding device 4a, 4b is not assigned to all incoming conveyor segments 1a, 1b. For example the holding device 4b can be omitted, so that an incoming conveyed object 17 to the conveyor segment 1b is always conveyed or conveyed with prioriy.

(38) FIG. 2 shows a further example of a material handling element Kb, which illustrates in particular that the controller 5 is not restricted to controlling the holding device 4a, 4b, but can also take on other tasks. In FIG. 2 the controller 5 is connected to sensors and/or reading devices 7a, 7b, by means of which the incoming conveyed objects 17 to the conveyor segments 1a, 1b can be identified and their current rank or current position in a sorting sequence can be determined. Furthermore, the starting line 8 indicates that the said detection of an incoming conveyed object 17 can also be communicated to other material handling elements Ka, Kb or also to a superordinate controller.

(39) In general a material handling element or node can be defined as any device for conveying and/or manipulating conveyed objects 17, which merges conveying streams and transports further via an outgoing conveyor segment or a plurality of such segments. For example this is clear from FIGS. 1 and 2 for channelers, confluences from secondary conveyor belts into a main conveyor belt and turntables. Material handling elements, which merge together conveying streams can also be formed for example by robots for unloading conveyed objects 17 from a storage.

(40) FIG. 3 shows an example of an arrangement comprising a storage 9 with a plurality of storage spaces L and a storage and retrieval machine 10, which comprises a car 12 running on rails 11 with a lifting platform 14 running vertically on a mast 13. The function of a storage and retrieval machine 10, which here operates as an unloading robot for the storage 9, is known per se and therefore does not need to be explained in detail at this point.

(41) FIG. 4 shows a schematic front view of the storage 9, showing a possible numbering of the storage spaces L1 . . . Lv.

(42) FIG. 5 now shows a logical or symbolic representation of the storage and retrieval machine 10 shown in FIG. 3. From FIG. 5 it can be seen that a number of incoming conveyor segments 2 corresponding to the number v of storage spaces L1 . . . Lv is concentrated on an outgoing conveyor segment 3. The concentration of the conveying stream is thereby formed by the lifting platform 14, which in this example can hold only one conveyed object 17 respectively. The storage and retrieval machine 10 can thus be regarded as a v-to-1-multiplexer.

(43) It is also possible that the lifting platform 14 can hold several conveyed objects 17 at the same time. A logical representation of a storage and retrieval machine 10 with a lifting platform 14 holding two conveyed objects 17 is shown in FIG. 6. Each of the storage positions thereby forms a logical node K1, K2. In this specific example it is assumed that the conveyed objects 17 are transported away to the right. This means that the object located at the node K1 can be transported away first, when the object transported via the node K2 has left the lifting platform 14. For this reason the output from the node K1 is guided as an input to node K2. Of course, other arrangements are also possible in which the conveyed objects 17 can leave the lifting platform 14 at the same time and the nodes K1, K2 are thus not linked in the shown manner. In general, a storage and retrieval machine can be regarded as a v-to-w multiplexer, wherein v is the number of storage spaces L1 . . . Lv reached by the storage and retrieval machine 10 and w is the number of objects transported simultaneously from the storage and retrieval machine 10 or storage positions provided on the lifting platform 14. From FIGS. 5 and 6 it is also shown in particular that the conveyor segments can also be seen in general as logical conveyor segments and should not necessarily be regarded purely in physical terms. In the case of a v-to-1 storage and retrieval machine at any one time point there is always only one incoming conveyor segment 1a, 1b.

(44) FIG. 7 shows a further example of an arrangement comprising a storage 9, a lift 15 arranged next to the storage 9 and a plurality of autonomous conveyor vehicles 16 (shuttles) operating on the individual storage levels. Such a shuttle 16, or such a removal robot removes a conveyed object 17 from a storage space L and transports it to the lift 15. The latter picks up the conveyed object 17 and transports it to a conveyor belt for further transport (not shown).

(45) The logical structure resulting from FIG. 7 is shown in FIG. 8. Here each shuttle 16 forms a node K1 . . . K4, to which the storage spaces L1 . . . L8 of a storage aisle are guided. The conveyor segments 3 coming from node K1 . . . K4 are guided in turn to the node K5 which represents the lift 15.

(46) FIG. 9 shows another arrangement comprising a storage 9 and shuttles 16, which is very similar to the arrangement shown in FIG. 7. The difference is that a paternoster 18 is provided instead of the lift 15.

(47) FIG. 10 shows a logical representation of the arrangement shown in FIG. 9. Under the condition that the paternoster 18 can transport the conveyed objects 17 in a circle, the latter is shown in FIG. 10 as a loop, wherein the nodes K5 . . . K8 form the transfer points to the individual levels of the storage 9 and the nodes K9 and K10 form two removal tracks, which can be arranged (physically) next to one another for example or can also be arranged above one another.

(48) FIG. 11 shows in addition a slightly more complex example of a conveying system. As already shown in FIGS. 5, 6, 8 and 10 a plurality of material handling elements Ka, Kb are coupled to one another such that at least one coupling 2 for an outgoing conveyor segment 3 of one material handling element Ka, Kb is connected directly or indirectly to an incoming conveyor segment 1a, 1b of another material handling element Ka, Kb. As already shown in FIGS. 5, 6, 8 and 10 the material handling elements or nodes K1 . . . K34 are only represented in simplified form.

(49) Directly in the above context means that the coupling 2 for an outgoing conveyor segment 3 of a material handling element Ka, Kb is connected to an incoming conveyor segment 1a, 1b of another material handling element Ka, Kb without the interconnection of other elements. For example this relates in FIG. 11 to nodes K5 and K16. Indirectly means that other elements are connected in between, in particular branch junctions and the like. For example, the connection between nodes K16 and K24 is indirect, as K19 and K22 are connected in between and act as a divergence.

(50) Specifically, the arrangement shown in FIG. 11 comprises a storage 9, a plurality of shuttles 16 operating autonomously therein as well as lifts 15 associated with the storage 9. In this example the storage 9 has three rows of shelving or aisles, wherein each aisle 32 comprises storage spaces L which are arranged in four levels with eight spaces in each. Thus the shuttles 16 represented by nodes K1 . . . K4 move in the first aisle, the shuttles 16 represented by nodes K6 . . . K9 move in the second aisle and the shuttles 16 represented by nodes K11 . . . K14 moves in the third aisle. The lifts 15 are represented by the nodes K5, K10 and K15.

(51) A horizontal loop 19 is connected to the lifts, in which loop the nodes K16 . . . K21 are arranged. The arrow denotes the conveying direction. Via nodes K19 and K20 conveyed objects 17 are transferred from the loop 19 into a network 20 which comprises a plurality of interlinked nodes K22 . . . K34. An optional sorting area 21 is arranged next to the network 20 and a picking area 22 is connected to the latter. In the picking area 22 there are three targets 23a . . . 23c to be supplied, for example workstations, at which conveyed objects 17 are loaded automatically or manually into packaging containers or onto pallets. In the example shown in FIG. 11 a sorting step 24 precedes one only destination 23a. However, it would also be possible to arrange a sorting step 24 in front of all destinations 23a . . . 23c or also in front of none of them.

(52) In the example shown in FIG. 11 a plurality of material handling elements/nodes K1 . . . K34 are connected to one another directly or indirectly in a ring. Thus at least a part flow is guided in a ring over the said material handling elements/nodes K1 . . . K34. In other words a feedback route is provided. For example node K21 is connected in a ring to node K18, node K32 to node K22, node K34 to node K23 and node K33 to node K21. In this way the ordering of the transported conveyed objects 17 can be increased in several run-throughs, or gaps in the sequence can be filled in step-by-step. The terms downstream and upstream can be used synonymously in relation to such a ring-like part flow. Of course, the feedback route shown in FIG. 11 is shown simply by way of example and is used to illustrate one of the possibilities. It would of course also be possible to use other ring-like connections.

(53) FIG. 11 also shows several divergences of the flow, for example at nodes K22 . . . K31. In general a divergence can be used to direct an outgoing flow into different areas of a conveying system or to different destinations 23a . . . 23c. In this case a node K22 . . . 101 with several outgoing conveyor segments 3 could also be divided into a node K22 . . . K31 with only one outgoing conveyor segment 3 and a downstream node with several outgoing conveyor segments 3.

(54) FIG. 12 shows a structure of an example of a conveying system, which is very similar to the structure shown in FIG. 11. Unlike the latter however, there is no ring-like conveyor, no feedback route and sorting step/sequencer 24. By means of the network 20 however errors in an actual sequence can still be corrected. For example objects, which leave the node K16 can be directed to node K19 or node K20. At node K22 the conveyed objects 17 originating from nodes K19 and K20 can be merged together again. The network can also be used in addition or alternatively to direct the conveyed objects 17 originating from the nodes K16, K17 and K18 to the destinations 23a, 23b and 23c.

(55) FIG. 13 shows a further example of a structure of a conveying system, which is very similar to the structure shown in FIG. 12. Unlike the latter however separate alternative routes 25 are provided for correcting errors in a sorting sequence of an incoming flow.

(56) The proposed method is now explained in more detail on the basis of the conveying system shown in FIG. 12:

(57) FIG. 14 shows a diagram, in which the path s is represented over time t. Specifically, the shown path runs through nodes K1, K5, K16, K19 or K20 and K22 to the destination 23a. FIG. 14 shows how the conveyed object 17 with serial number C1 moves from node K1 to the destination 23a and arrives after time interval t1 at time point TC1.

(58) FIG. 15 shows in addition the path of the conveyed object 17 with serial number C2. The latter is released at node K5 and reaches the destination 23a after the time interval t2 at time point TC2. As shown in FIG. 15, the conveyed object 17 with serial number C2 moves slightly slower than the one with serial number C1.

(59) Lastly, FIG. 16 shows the path of the conveyed object 17 with serial number A1. The latter moves from node K5 relatively swiftly to node K16 and then slightly slower to node K20, at which it is held for a time period Finally, it also moves to destination 23a and reaches this at time point TA1. The time required from node K5 to node K16 is denoted by t3, the time required from node K16 to node K20 is denoted by t4, the waiting time at node K20 is denoted by t5 and the time required from node K5 to the destination 23a is denoted by t6.

(60) The path of the conveyed objects 17 through the conveying system is planned in advance. According to the proposed method for bundling conveying streams for the conveyed objects 17 target arrival time points TA1, TC1 and TC2 are calculated, at which the conveyed objects 17 are scheduled to arrive at the destination 23a. Furthermore, for a conveyed object 17 waiting at a material handling element/node K1, K5, K16, K19, K20 and K22 a target run-through time t1, t2, t6 is calculated which the conveyed object 17 needs for scheduled transport from a current position to the destination 23a. The target run-through time of the conveyed object 17 with serial number C1 from node K1 to destination 23a is t1, the target run-through time of the conveyed object 17 with serial number C2 from node K5 to destination 23a is t2, the target run-through time of the conveyed object 17 with serial number A1 from node K5 to node K16 is t3 and so on. A conveyed object 17 is then released at a release time point which corresponds essentially to the target arrival time point TA1, TC1, TC2 minus the target run-through time t1, t2, t3, etc.

(61) According to the plan the target run-through time of the conveyed object 17 with serial number A1 is calculated from node K5 to the destination 23a by t3+t4+t5+t6. The said conveyed object 17 is therefore released at node K5 at time point TA1(t3+t4+t5+t6), at node K16 at time point TA1(t4+t5+t6), and at node K20 at time point TA1-t6. For the other conveyed objects 17 the calculation is performed in a similar manner.

(62) By means of the proposed method the conveyed objects 17 arrive at the destination 23a at a predefinable time point TA1, TC1, TC2, provided that the plan is executed without error or with negligible errors.

(63) In particular, the target arrival time points TA1, TC1, TC2 are calculated according to a sorting sequence. In the present example it is assumed that the conveyed objects 17 should arrive at the destination 23a in the sequence C1, C2 and A1. It should be noted at this point that the predefined target arrival time points TA1, TC1, TC2 only represent one of several solutions for the required sequence C1, C2 and A1 and the sequence C1, C2 and A1 can also be achieved by other target arrival time points TA1, TC1, TC2.

(64) FIG. 17 shows that it is advantageous to release a first conveyed object 17 with the serial number A1 waiting at a material handling element/node K22 after a second conveyed object 17 with serial number A2, which has a target arrival time point TA2 further in the future, as long as the target run-through time for the second conveyed object A2 is longer than for the first conveyed object A1.

(65) The conveyed objects 17 can generally only pass a node Ka, Kb, K1 . . . K34 consecutively with a delay time in between. In the example shown in FIG. 17 this delay time is indicated by t7.

(66) If the conveyed object 17 with serial number A2 is now released at time point T1 and the conveyed object 17 with serial number A1 is released after the delay time t7 (as indicated above), then this results in an occupancy time t8 of the conveyor section between the node K22 and the destination 23a. If however the conveyed object 17 with serial number A1 is released at time point T1 and the conveyed object 17 with serial number A2 is released after the delay time t7, then there is an occupancy time t9 of the conveyor section between the node K22 and the destination 23a which is much longer than the occupancy time t8. By means of the proposed measures thus the occupancy time of a conveyor section can be minimized. It should be noted that the sorting sequence A1.fwdarw.A2 is met by both variants. The former requires less time, as already mentioned. The occupancy time of the conveyor section is thus defined in particular as the time interval which a conveyed object 17 needs to run through said conveyor section.

(67) In reality required target release time points cannot always be adhered to. For example, there may be unforeseen disruptions on the conveyor system which delay the movement of the conveyed objects 17 at least on a portion of the conveying system. The right half of FIG. 17 shows an example in which the sorting sequence A1.fwdarw.A2.fwdarw.A3 would be desirable, but the release at node 22 can only start at time point T2.

(68) The above procedure, i.e. the release of conveyed object A2 before conveyed object A1, results in a low occupancy time as discussed, but causes a sorting error, as the conveyed objects 17 arrive in the sequence A3.fwdarw.A1.fwdarw.A2.

(69) In a further advantageous embodiment variant of the proposed method a first conveyed object 17 waiting at a material handling element/node K22 with serial number A1 is released before a second conveyed object 17 with the serial number A2 and a target arrival time point TA2 further in the future, if the target run-through time for the second conveyed object A2 is longer than for the first conveyed object A1 and the first conveyed object A1 thereby arrives at the destination 23a before a third conveyed object A3, the target arrival time point TA3 of which is after the target arrival time point TA2 of the second conveyed object A2. By means of this procedure sorting errors are reduced, as shown on the right of FIG. 17. If the conveyed object A1, as proposed, is released before the conveyed object A2, the conveyed objects 17 arrive at the destination 23a in the sequence A1.fwdarw.A3.fwdarw.A2. Compared to the sorting sequence A3.fwdarw.A1.fwdarw.A2 referred to above the sorting sequence A1.fwdarw.A3.fwdarw.A2 has one sorting error fewer.

(70) The method performed by the controller 5 is explained in more detail in the following with reference to a slightly different illustration:

(71) In a first step the target arrival time points for the conveyed objects 17 are calculated. In the example it is assumed that three destinations 23a . . . 23c are supplied with conveyed objects 17 and thus three target sorting sequences A1 . . . A3, B1 and C1 . . . C3 are formed. This means that the conveyed object 17 should arrive at a first destination 23a in the sequence A1, A2, A3, at a second destination 23b only the conveyed object B2 and at a third destination 23c in the sequence C1, C2, C3. The corresponding target arrival time points are denoted TA1 . . . TA3, TB1 and TC1 . . . TC3. In general said target arrival time points TA1 . . . TA3, TB1 and TC1 . . . TC3 can be saved in a memory or a table of the controller 5 and/or a superordinate controller. In the table in addition also the target run-through times can be saved. Target release time points can also be saved in the table.

(72) FIG. 18 shows the situation at node Kx at a first time point, namely the physical arrangement of several conveyed objects 17 and their assigned target arrival time points TA1 . . . TA3, TB1 and TC1 . . . TC3. In particular, it is assumed in this example that the objects C1, C2 and A1 have already passed node Kx and objects B1 and A2 have been stopped at the node Kx.

(73) In this example it is assumed that the target arrival time point TB1 of the conveyed object 17 with serial number B1 is before the target arrival time point TA2 of the conveyed object 17 with serial number A2. Thus the conveyed object B1 is released before conveyed object A2. In FIG. 19 a situation is shown in which the conveyed object B1 has already passed node Kx, but the conveyed object A2 is still waiting there however.

(74) FIG. 20 shows a situation at a node Ky downstream of node Kx at a later time point. The objects originating from node Kx thereby arrive at the left branch of node Ky. It is now assumed that the objects C1, C2, A1 have already passed node Ky and the objects B1, A2 are also waiting at node Ky. In addition, object C3 is waiting on the right branch.

(75) In this example it is assumed that the target arrival time point TC3 of the conveyed object 17 with serial number C3 is before the target arrival time point TB1 of the conveyed object 17 with serial number B1. Thus the conveyed object C3 is released before conveyed object B1. FIG. 21 shows a situation in which the conveyed object C3 has already passed node Ky, however the conveyed object B1 is still waiting there.

(76) Furthermore, FIG. 22 shows a situation at a node Kz downstream of Ky at a later time point. The objects coming from node Ky arrive on the left branch of node Kz. It is assumed that the object C1 has already passed node Kz and the objects C2, A1, C3, B1, A2 are still waiting at node Kz. In addition the object A3 is waiting on the right branch of the node Kz.

(77) In the relevant example it is assumed that the target arrival time point TC2 of the conveyed object 17 with serial number C2 is before the target arrival time point TA3 of the conveyed object 17 with serial number A3. Thus the conveyed object C2 is released before the conveyed object A3. FIG. 23 shows a situation in which all conveyed objects A1 . . . A3, B1, C1 . . . C3 have passed the node Kz and are in the required sequence.

(78) If over the course of the conveying route there is a buffer, a sequencer 24, an alternative route 20, 25 or a feedback route 19, temporary sorting errors can be taken into account specifically in the planning of the conveying sequence. For example it is advantageous if a conveyed object 17 is conveyed into a buffer, a sequencer 24, an alternative route 20, 25 or a feedback route 19 and is stopped there until this position has been passed by a conveyed object 17 preceding the relevant conveyed object 17 in the sorting sequence, if this results in a reduction of the occupancy time of the conveying system.

(79) FIG. 24 shows in addition a situation after the node Kz, in which the conveyed object 17 with serial number A3 causes a sorting error. To illustrate the proposed method FIGS. 25 to 28 show the removal of the temporary sorting error. For this the conveyed object A3 causing the sorting error is ejected from the object A3 conveyed flow and reintroduced at a later time point.

(80) In FIG. 25 the object A3 is therefore directed at node Kr into a left branch and stopped at a node Ks, whilst the objects C2, A1, C3, B1 are channeled directly through the node Krs and Ks. At a later time point thus objects A2 and A3 wait at the node Ks. This situation is shown in FIG. 26. FIG. 27 then shows the correct sorting, which also corresponds to the sorting already shown in FIG. 23, but after the node Ks. In the above example the conveyed object A3 has been conveyed into an alternative route. The process is similar if the conveyed object A3 is transported alternatively into a buffer, a sequencer 24 or a feedback route 19.

(81) FIG. 28 shows a situation in which a plurality of conveyed objects 17 have the same serial number in the sorting sequence. Specifically two objects A2 and two objects C1 are provided. This procedure is practical if a plurality of similar objects need to arrive in a specific position at the destination. For example the objects A2 could be a plurality of similar water bottles, where it does not matter which water bottle is arranged at which possible position for water bottles.

(82) FIG. 28 shows a situation at node Kz, which is comparable to the situation shown in FIG. 22. The objects coming from node Ky enter the left branch of node Kz. It is assumed that the object C1 has already passed the node Kz and an additional object C1 and the objects A1, C2, B1, A2 continue to wait at node Kz. In addition, an additional object A2 is waiting on the right branch of the node Kz.

(83) In principle the target arrival time points TA2 for both conveyed objects A2 can be the same or different. Thus also the target arrival time points TC1 for both conveyed objects C1 can be the same or different. In the present example it is now assumed that the target arrival time points TC1 are before the target arrival time points TA2. Thus at the node Kz the conveyed object 17 with serial number C1 is released. The correction of a sorting error in a buffer, sequencer 24, alternative route 20, 25 or feedback route 19 downstream of the node Kz is also possible in this method variant.

(84) Of course, by means of the proposed method it is possible to remove not only planned sorting errors but also unplanned sorting errors. The latter can be caused for example by disruptions on the conveying system. According to the proposed method a second conveyed object 17, which follows a first conveyed object 17 in a sorting sequence, is conveyed into a buffer, a sequencer 24, an alternative route 20, 25 or a feedback route 19 and held there until this position has been passed by the first conveyed object 17, if the first conveyed object 17 on the conveying system was delayed in an unscheduled manner and no target arrival time point is possible before the target arrival time point of the second conveyed object 17 without using the buffer, the sequencer 24, the alternative route 20, 25 or the feedback route 19.

(85) It is particularly advantageous in this connection if the target arrival time points TA1 . . . TA3, TB1, TC1 . . . TC3 for those conveyed objects 17, which have not yet reached their destination 23a . . . 23b, are recalculated in consideration of the said unscheduled delay. In this way the planning or the further execution of the method is supported by foreseeable circumstances.

(86) It is particularly advantageous if a plurality of variants of target arrival time points TA1 . . . TA3, TB1, TC1 . . . TC3 each having a predefined sorting sequence for a plurality of conveyed objects 17, which have not yet arrived at their destination 23a . . . 23b, are calculated in consideration of the said unscheduled delay and the particular variant is actually executed which has the lowest occupancy time on the conveying system.

(87) It is advantageous if at least those method steps which are related to a decision about the release of a conveyed object 17, apart from the consideration of a target arrival time point TA1 . . . TA3, TB1, TC1 . . . TC3/a target run-through time/a target release time point are performed independently of all other material handling elements/nodes Ka . . . Kz, K1 . . . K34 and/or independently of a central controller. In this way the communication and thus the cost of communication lines between the material handling elements K1 . . . K34 can be minimized.

(88) In this connection it is also an advantage if the programming logic relating to the release of a conveyed object 17 in all material handling elements K1 . . . K34 is configured to be identical, or if the method steps relating to the release of a conveyed object 17 in all material handling elements K1 . . . K34 are performed in an identical manner. In this way the effort of producing or programming the controller for a conveying system can be minimized overall, as the latter is made up of several identical modules. Also the cost of any troubleshooting can be minimized.

(89) To form a predefined sorting sequence it is also an advantage if conveyed objects 17 are removed from storage in order to be supplied with respect to the destinations 23a . . . 23c and with respect to a sorting sequence for a destination 23a . . . 23c. This means that firstly those conveyed objects 17 for a destination 23a . . . 23c are removed from storage with the lowest position in a sequence, then the conveyed objects 17 with the second lowest position etc. In addition, the conveyed objects 17 for a specific destination 23a . . . 23c are also removed from storage in an ordered manner. If for example in the aisle of the storage 9, from which the material handling elements K1 . . . K4 are used for the removal, for example conveyed objects 17 number 3 and number 5 of the target 23a and the conveyed objects 17 number 1 and 7 of the target 23b, the conveyed objects 17 are removed from storage in the sequence A3, A5, B1, B7. In this example, it is assumed that the missing conveyed objects 17 (e.g. A1, A2, A4, B2, B3, etc.) of the sequence are located in other aisles, which are removed from storage by other material handling elements K6 . . . K9, K11 . . . K14. In this way overall it is possible to achieve a higher degree of ordering of the conveying streams provided by the conveying technology.

(90) Alternatively, it would also be possible that the conveyed objects 17 are ordered with regard to a sorting sequence for a destination 23a . . . 23c to be supplied, with respect to the destinations 23a . . . 23c but are removed from the storage 9 chaotically or in an unordered manner. With regard to the previously stated example, this means that the conveyed objects 17 can also be removed from storage for example in the sequence B1, A3, A5, B7 or for example in the sequence B1, A3, B7, A5. By means of the unordered removal from storage at the destination level the throughput during the removal from storage can be increased, for example if transport routes of the material handling elements K1 . . . K15 are minimized during the removal from storage.

(91) In order to identify blockages on the conveying system or remove them, it is also possible in an advantageous embodiment that the releases of the nodes K1 . . . K34 per unit of time are monitored by a superordinate controller and the holding device 4a, 4b is released at which the conveyed object 17 with the lowest serial number is waiting, if a threshold is not met for the releases per unit of time.

(92) For example if the value for the releases per unit of time decreases from a relatively constant value (e.g. 50 releases per minute) to a very low value or even zero, it can be assumed that there is a blockage on the conveying system. By means of superordinate intervention the blockage can be resolved. Instead of releasing the conveyed object 17 with the lowest serial number the release can also be performed randomly for example.

(93) It is also advantageous if the threshold is adjusted according to the number of conveyed objects 17 located on the conveying system. This means that the threshold is increased if the number of transported objects 17 increases and vice versa. In this way a decreasing number of releases, which is substantiated by a low number of transported conveyed objects 17, is not misinterpreted as a blockage.

(94) For example, a situation of this kind may occur when starting a picking order or for example also when the latter is almost complete. In both cases there are comparatively few objects 17 on the conveying system because they are mostly still in the storage 9 or have already been loaded into packaging containers. It is also advantageous if pausing the removal of conveyed objects 17 at a destination 23a . . . 23c. is taken into consideration. Particularly, with manual picking processes there are necessarily interruptions in the working sequence, for example if a worker is taking a break or has gone to the bathroom. In this case there can also be a decrease in the number of releases per unit of time which is not caused by a blockage.

(95) In this connection it is also advantageous if the removal of conveyed objects 17 from the storage 9 is adjusted according to the removal of conveyed objects 17 at the destination 23a . . . 23c. This means that the number of conveyed objects 17 removed per unit of time from the storage is lowered, if the number of conveyed objects 17 removed per unit of time at the destination 23a . . . 23c falls and vice versa.

(96) In one variant of the described method the releases per unit of time for each destination 23a . . . 23c to be supplied are monitored by a superordinate controller. Thus the holding device 4a, 4b is released at which the conveyed object 17 with the lowest target arrival time point TA1 . . . TA3, TB1, TC1 . . . TC3 of the relevant target 23a . . . 23c is waiting, if for the releases per time unit assigned to the relevant destination 23a . . . 23c a threshold is not met.

(97) The controller 5 is generally set up to release a conveyed object 17 at a release time point which corresponds essentially to the target arrival time point TA1 . . . TA3, TB1, TC1 . . . TC3 minus the target run-through time t1, t2, t6. Furthermore, it is also possible that the controller 5 is set up to calculate a target run-through time t1, t2, t6 for a conveyed object 17 waiting at a material handling element/node Ka . . . Kz, K1 . . . K34, which the conveyed object 17 needs for transporting as scheduled from a current position to the destination 23a . . . 23c. Alternatively, this calculation or the calculation of the target release time points can also be performed by a superordinate controller. The calculation of the target arrival time points TA1 . . . TA3, TB1, TC1 . . . TC3 for the conveyed objects 17, at which the latter are to arrive as scheduled at a destination 23a . . . 23c, is advantageously performed by a central or superordinate controller.

(98) It should be noted at this point that the removal of sorting errors explained with reference to FIGS. 24 to 27, whether they are planned or unplanned errors, can be applied without the features of claim 1, that is without the control of the conveyor sequence with reference to the target arrival time points TA1 . . . TA3, TB1, TC1 . . . TC3. Furthermore, another sorting algorithm can be superordinate to the removal of sorting errors.

(99) For example, a plurality of triggering devices downstream of the incoming conveying segments 1a, 1b and linked logically to the OR link are used for the release of a holding device 4a, 4b or a conveyed object 17, and a holding device 4a, 4b or a conveyed object 17 waiting at the latter is released when a conveyed object 17 preceding the waiting conveyed object 17 in a sorting sequence passes one of the linked releasing devices or there is no preceding conveyed object 17.

(100) FIG. 29 shows similar to FIG. 1 an example of a material handling element Kc for bundling conveying streams, in which the controller 5 is connected on the input side to a plurality of triggering devices X which are arranged downstream of the material handling element/node Kc. A conveyed object 17 with the serial number n is only released in this method if the immediately or directly preceding conveyed object 17 with serial number n1 passes an OR linked triggering device X, whereby it is possible in principle to form an accurate actual sorting sequence at the destination 23a . . . 23c.

(101) Similar to FIG. 11 FIG. 30 shows an example of how the triggering devices X can be distributed in a conveying system. Specifically in this example a plurality of triggering devices X1 . . . X22 are provided. Here to each shuttle 16 a triggering device X1 . . . X4, X6 . . . X9 and X11 . . . X14 is assigned on the receiving platform and to each lift 15 a triggering device X5, X10 and X15 is assigned on the lifting platform.

(102) It should be noted in particular that the arrangement of the triggering devices X1 . . . X22 is simply shown by way of example in order to illustrate the functioning of the conveying system shown in FIG. 30 and of course can also be different. In particular, no triggering devices X1 . . . X22 are marked in the network 20 for illustrative purposes. In a real system of course triggering devices X1 . . . X22 can be provided at any point in the network 20. Furthermore, it should be noted that the interconnection of the nodes K1 . . . K34 with the triggering devices X1 . . . X22 is also not shown explicitly in FIG. 30, but would of course be present in a real implementation of the conveying system.

(103) For example the triggering devices X5 and X16 can be connected to the inputs 6 of the material handling element K1. For example, the triggering devices X16 . . . X19 can be connected to the material handling element K21. The material handling element K24 can be connected to not shown triggering devices in the network 20 and so on.

(104) It is also possible in connection with this sorting method to allow errors in a sorting sequence and to correct them by means of a buffer, sequencer 24 an alternative route 20, 25 or a feedback route 19 arranged downstream of the material handling element node Ka . . . Kz, K1 . . . K34. It is also possible here that a plurality of conveyed objects 17 have the same serial number in a sorting sequence, such as if similar conveyed objects 17 are to be grouped in a conveying stream.

(105) In summary, it can be said that the method defined according to one aspect of the invention can also be applied independently of the features of another aspect of the invention, in particular in association with another sorting method, wherein further aspects of the invention can also be applied by analogy. This results in a method for bundling conveying streams at a material handling element/node Ka . . . Kz, K1 . . . K34 with a plurality of incoming conveyor segments 1a, 1b, at least one coupling 2 to an outgoing conveyor segment 3, to which the incoming conveyor segments 1a, 1b are merged, and a plurality of holding devices 4a, 4b for stopping conveyed objects 17 or a conveying stream on the incoming conveyor segments 1a, 1b, wherein

(106) a conveyed object 17 is conveyed into a buffer, a sequencer 24, an alternative route 20, 25 or a feedback route 19 and is held there, until this position has been passed by a conveyed object 17 preceding the relevant conveyed object 17 in the sorting sequence, if this results in the reduction of the occupancy time of the conveying system.

(107) The result is thus a material handling element/node Ka . . . Kz, K1 . . . K34 for bundling conveying streams comprising a plurality of incoming conveyor segments 1a, 1b, at least one coupling 2 to an outgoing conveyor segment 3, to which the incoming conveyor segments 1a, 1b are merged, and a plurality of holding devices 4a, 4b for stopping a flow on the incoming conveyor segments 1a, 1b, additionally comprising a controller 5, which is configured, to convey a conveyed object 17 into a buffer, a sequencer 24, an alternative route 20, 25 or a feedback route 19 and keep it there until this position has been passed by a conveyed object 17 preceding the relevant conveyed object 17 in the sorting sequence, if this reduces the occupancy time of the conveying system.

(108) Furthermore, also the method according to another aspect of the invention is independent of the features of another aspect of the invention, and can also be applied in particular in connection with another sorting method, wherein further aspects of the invention can also be applied accordingly. This thus results in a method for bundling conveying streams at a material handling element/node Ka . . . Kz, K1 . . . K34 with a plurality of incoming conveyor segments 1a, 1b, at least one coupling 2 to an outgoing conveyor segment 3, to which the incoming conveyor segments 1a, 1b are merged and a plurality of holding devices 4a, 4b for stopping conveyed objects 17 or a flow to the incoming conveyor segments 1a, 1b, wherein

(109) a second conveyed object 17, which follows a first conveyed object 17 in a sorting sequence, is conveyed into a buffer, a sequencer 24, an alternative route 20, 25 or a feedback route 19 and is held there until this position has been passed by the first conveyed object 17, if the first conveyed object 17 has been delayed in an unscheduled manner on the conveying system and it is no longer possible to have a target arrival time point before the target arrival time point of the second conveyed object 17 without using the buffer, the sequencer 24, the alternative route 20, 25 or the feedback route 19.

(110) This thus results in a material handling element/node Ka . . . Kz, K1 . . . K34 for bundling conveying streams, comprising a plurality of incoming conveyor segments 1a, 1b, at least one coupling 2 for an outgoing conveyor segment 3, to which the incoming conveyor segments 1a, 1b are merged, and a plurality of holding devices 4a, 4b for stopping a flow on the incoming conveyor segments 1a, 1b, also comprising a controller 5 which is configured to convey a second conveyed object 17, which follows a first conveyed object 17 in a target sorting sequence, into a buffer, a sequencer 24, an alternative route 20, 25 or a feedback route 19 and to hold it there until this position has been passed by the first conveyed object 17, if the first conveyed object 17 has been delayed on the conveying system in an unscheduled manner and the target arrival time point is no longer possible before the target arrival time point of the second conveyed object 17 without using the buffer, the sequencer 24, the alternative route 20, 25 or the feedback route 19.

(111) At this point it should be noted that the combination of some aspects of the invention or the combination of previously mentioned variants (i.e. their and/or link) can be applied independently of the features of another aspect of the invention, and in particular in connection with another sorting method, wherein further aspects of the invention can also be applied by analogy.

(112) Generally, the controller 5 can consist of hardware or can also be in the form of a software algorithm which is performed in a processor. It is also possible that a plurality of entities of the said software algorithm are performed in a computer.

(113) Advantageously, the material handling elements/nodes Ka . . . Kz, K1 . . . K34 have access by writing and/or reading a common table with target arrival time points TA1 . . . TA3, TB1, TC1 . . . TC3. For example the latter can be stored in a central controller. If the controllers 5 are formed by a plurality of entities of a software algorithm in a computer, then the common table can be stored in particular on said computer.

(114) The physical connection between controllers 5, the connection of one controller 5 to a superordinate controller or also the connection of the triggering devices X1 . . . X22 to the controllers 5 is wire-connected or wireless. For example, said connections can be formed by a bus system or by means of a wireless network.

(115) Generally material handling elements K1 . . . K34 with a different release strategy can be used in a conveyor system. For example the material handling elements K1 . . . K15 can be set up to release a conveyed object 17 with the serial number n when one of the preceding conveyed objects 17 with serial number n1 or n2 passes one of the OR-linked triggering devices X1 . . . X22, whereas the other material handling elements K16 . . . K34 can be set up for example to perform a release method with the aid of the addressed time control. If necessary, the guide-lines for releasing a conveyed object 17 can also be adjusted dynamically during operation, for example by a superordinate controller.

(116) The embodiments show possible embodiment variants of a material handling element Ka . . . Kz, K1 . . . K34 according to the invention or a conveyor system according to the invention, whereby it should be noted at this point that the invention is not restricted to the embodiment variants shown in particular, but rather various different combinations of the individual embodiment variants are also possible and this variability, due to the teaching on technical procedure, lies within the ability of a person skilled in the art in this technical field. Thus all conceivable embodiment variants are possible, which are formed by combining individual details of the embodiment variants shown and described.

(117) In particular it should be noted that the shown devices in reality can also comprise more components than are shown.

(118) Lastly, as a point of formality it should be noted that for a better understanding of the structure of a material handling element Ka . . . Kz, K1 . . . K34 or a conveyor system according to the invention the latter or its components have not been shown to scale in part and/or have been enlarged and/or have been reduced in size.

(119) The independent solutions according to the invention can be taken from the description.

LIST OF REFERENCE NUMERALS

(120) 1a, 1b incoming conveyor segment 2 coupling for outgoing conveyor segment 3 outgoing conveyor segment 4a, 4b holding device 5 controller 6 input 7a, 7b sensor/reading device 8 output line 9 storage 10 storage and retrieval machine 11 rails 12 car 13 mast 14 lifting platform 15 lift 16 conveyor vehicle (shuttle) 17 conveyed object 18 paternoster 19 loop 20 network 21 sorting area 22 picking area 23a . . . 23c destination sorting step alternative route A1 . . . A3 serial number conveyed object first destination B1 serial number conveyed object second destination C1 . . . C3 serial number conveyed object third destination K1 . . . K34 material handling element/node L, L1 . . . L8, Lv storage space X, X1 . . . X22 triggering device