METHOD FOR OPERATING A TRANSPORT SYSTEM AND CORRESPONDING TRANSPORT SYSTEM

Abstract

A transport system may include at least two conveyor sections and at least three cars that are moved individually in a cyclical operation. Each car may pass through a first conveyor section starting from a first start position and subsequently pass through a second conveyor section back to the first start position. At least one stopping point may be provided at least along a conveyor section, and one or more subsequent stopping points may respectively be assigned to a block. Travel of the cars may be controlled such that the cars successively approach a respective previously-specified block, and an equal cycle time is predefined for every car to pass through the first and second conveyor sections. A method for operating a transport system in this manner is also disclosed.

Claims

1.-25. (canceled)

26. A method for controlling a transport system, the method comprising moving at least three cars individually in a cyclical operation, wherein each of the at least three cars passes through a first conveyor section starting from a first start position and subsequently passes through a second conveyor section and back to the first start position, wherein at least one stopping point is provided along the first conveyor section or the second conveyor section, wherein blocks into which the first and second conveyor sections are divided each include one or more additional stopping points, the method further comprising controlling travel of the at least three cars such that the at least three cars respectively and successively approach a previously-specified block of the blocks, wherein each of the at least three cars passes through the first and second conveyor sections in an equal cycle time that has been predefined.

27. The method of claim 26 wherein a number of the blocks=j, wherein travel of a first group of j cars of the at least three cars is controlled such that a first car of the at least three cars approaches a first block of the blocks, which is the previously-specified block for the first car, a following second car of the at least three cars approaches a second block of the blocks, which is the previously-specified block for the second car, and a j-th car of the at least three cars approaches a j-th block of the blocks, which is the previously-specified block for the j-th car, wherein the j-th block is closer to a first home position defined by the first start positions of the at least three cars than the second block, wherein the second block is closer to the first home position than the first block.

28. The method of claim 27 wherein each successive group of j cars that follows the first group approaches the blocks in a same way as the first group of j cars.

29. The method of claim 27 wherein the blocks are divided into directly successive blocks.

30. The method of claim 27 wherein cars of the first group of j cars are selected as directly successive cars.

31. The method of claim 27 wherein the previously-specified block of the blocks is within the first conveyor section, wherein the at least three cars respectively and successively also approach a previously-specified block of the blocks in the second conveyor section, wherein in both the first and second conveyor sections each of the at least three cars stops at at least one of the one or more additional stopping points within the respective previously-specified blocks in the first and second conveyor sections, wherein the respective second conveyor section of each of the at least three cars is assigned a second start position, with the second start positions defining a second home position, the method further comprising controlling travel of the first group of j cars to the blocks of the second conveyor section in a same way with respect to the second home position as the travel of the first group of j cars to the blocks of the first conveyor section with respect to the first home position.

32. The method of claim 31 wherein after the second start position one of the at least three cars makes an intermediate stop at a stopping point after leaving the previously-specified block.

33. The method of claim 26 wherein the previously-specified block of the blocks is within the first conveyor section, wherein the at least three cars respectively and successively also approach a previously-specified block of the blocks in the second conveyor section, wherein in both the first and second conveyor sections each of the at least three cars stops at at least one of the one or more additional stopping points within the respective previously-specified blocks in the first and second conveyor sections.

34. The method of claim 26 wherein the first conveyor section of a first car of the at least three cars differs from the first conveyor section of a second car of the at least three cars.

35. The method of claim 26 wherein each of the at least three cars stops at at least one predetermined stopping point per cycle.

36. The method of claim 35 wherein the at least one predetermined stopping point has a longest average stopping time of any stopping point.

37. The method of claim 35 wherein one of the at least one predetermined stopping points for the at least three cars is the first start position of one of the at least three cars.

38. The method of claim 35 wherein a stopping time at the at least one predetermined stopping point for each of the at least three cars is selected so that the at least three cars comply with the equal cycle time.

39. The method of claim 26 wherein each of the at least three cars stops at a plurality of predetermined stopping points per cycle, wherein travel times of each of the at least three cars between two successive of the plurality of predetermined stopping points are equal.

40. The method of claim 26 wherein one of the at least three cars makes an intermediate stop after leaving its first start position and before reaching its previously-specified block.

41. The method of claim 40 wherein a stopping time at the intermediate stop is selected so that the one of the at least three cars complies with the equal cycle time.

42. The method of claim 26 wherein a maximum stopping time per stopping point is predefined as a function of the equal cycle time.

43. The method of claim 26 comprising changing as a function of demand and/or time of day at least one of: an assignment of the one or more additional stopping points of the blocks; a number m of the at least three cars in the transport system; the equal cycle time for the at least three cars; a number of the at least three cars per block; or quantity and positions of predetermined stopping points.

44. A transport system comprising: a first conveyor section; a second conveyor section; at least three cars that are movable individually in a cyclical operation, wherein during the cyclical operation each of the at least three cars passes through the first conveyor section starting from a first start position and subsequently passes through the second conveyor section and back to the first start position, at least one stopping point disposed along the first conveyor section or the second conveyor section, wherein blocks into which the first and second conveyor sections are divided each include one or more additional stopping points; and a control device configured to control travel of the at least three cars such that the at least three cars respectively and successively approach a previously-specified block of the blocks, wherein each of the at least three cars passes through the first and second conveyor sections in an equal cycle time that has been predefined.

45. The transport system of claim 44 wherein the transport system is configured as an elevator, wherein the first and second conveyor sections include at least two shafts, wherein the at least three cars are configured as elevator cars that are disposed in the at least two shafts and are individually movable, wherein the first conveyor section comprises an upward-leading shaft of the at least two shafts and the second conveyor section comprises a downward-leading shaft of the at least two shafts.

Description

DESCRIPTION OF THE FIGURES

[0068] FIG. 1 is a schematic view of an exemplary embodiment of a transport system according to the invention which is configured as an elevator system, and

[0069] FIG. 2 is a schematic view of an exemplary travel diagram for three cars of an elevator system according to FIG. 1 according to an embodiment of a control method according to the invention.

[0070] FIG. 1 is a schematic view of an elevator system 1 as a transport system with two conveyor sections which are embodied as shafts 2, 3 and a total of six individually movable elevator cars, that is to say elevator cars which can be moved separately and therefore largely independently of one another. The elevator cars are here cars of the transport system. Therefore, a first conveyor section forms a first upward-leading shaft 2 and a second conveyor section forms a downward-leading second shaft 3. Each conveyor section has at its end a transfer device 4 which is configured in a manner known per se to transfer a car from the first shaft 2 into the second shaft 3 or from the second shaft 3 into the first shaft 2. In the exemplary embodiment shown, the transfer devices 4 are located in the bottom or top story of the building 5. The shafts 2 and 3 are embodied in this exemplary embodiment as building shafts. However, it is also possible to use a single building shaft in which the cars can be moved upward or downward along conveyor sections which run in parallel.

[0071] In the elevator system 1 illustrated here, each car can be moved independently of any other car by means of linear drives. An implementation of the illustrated cyclical multi-car elevator system as a cable elevator is in principle conceivable but is structurally costly and complex.

[0072] In the cyclical multi-car elevator system 1 illustrated in FIG. 1, m cars can move similarly to a paternoster in a circulation operation, wherein the cars are denoted by the reference numbers 11 to 16 (m=6). In general, there are p shafts between which upward and downward transfer can take place. In the illustrated case, p is equal to 2. In contrast to the paternoster principle, each car is driven independently of the other cars and can therefore stop at any desired stopping point independently of the other cars. The stories are denoted by 6. If the elevator system serves n stories, it has a total of q=n×p stopping points. In the illustrated exemplary embodiment, n equals 8, so that q=16.

[0073] For the exemplary embodiment illustrated in FIG. 1, the control of the elevator system 1 is defined by means of the schematically illustrated control device 7, which is operatively connected to the drives of the cars 11 to 16, in a plurality of steps:

a) Division into Blocks:

[0074] Firstly, all the n stories 6 of the associated building 5 are divided into j logical blocks, where j≦n. The blocks can each comprise an equal or similar number of stories or else an intentionally different number of stories, in order to take into account the different demand at different stories. In the present case, j equals 3 and the three blocks are denoted by 21, 22 and 23. The blocks 22 and 23 each comprise three stories, while the top block 21 comprises merely two stories. Each block can be assigned an equal number or a different number of cars which serve the respective block. The number of cars assigned to a block shall be k. In FIG. 1, j equals 3, and k=2 can be selected for each block. However, different numbers k can also be selected for each block. With a further explanation, k=2 and m=k×j=6.

b) Determination of the First Start Position:

[0075] For the building 5 under consideration, the stopping point with the longest average stopping duration is determined, since this constitutes the bottleneck for the traffic volume. This is referred to as the critical stopping point. A critical stopping point can be located, typically, in a ground floor lobby in which a very large number of passengers enter or leave an elevator, resulting in correspondingly long stationary times for the cars. In the exemplary embodiment according to FIG. 1, the ground floor forms the first start position which is common to all the cars, and therefore the first home position in the upward-leading first shaft 2. Depending on the configuration of the building, it is also possible for a different stopping point to constitute this first start position. It will now be specified that all the cars 11 to 16 always stop at this first start position on their circulation, in order to permit passengers to change over. This first start position therefore defines the starting point for the cycles of the cars and defines a critical stopping point.

c) Partial Cycle in the First Shaft:

[0076] For the sake of simpler explanation, it will be assumed below that the critical stopping point is the entry for the passengers on the ground floor of the building, which will actually usually be the case, for example during the morning upward traffic. Starting from this stop, that is to say from the first start position, the m=6 cars 11 to 16 then successively approach their respective block and in doing so transport their passengers to said block. In this context, it is decisive for efficient operation that the cars serve the j=3 blocks 21 to 23 in the suitable sequence. In this context, car 11, which serves the top block 21, moves away first, followed by the car 12 for the block 22 which is second from the top, in turn followed by the car 13 for the lowest block 23. The next group of three cars 14 to 16 is assigned to the blocks 21 to 23 in the same way as the first three cars 11 to 13, with the result that the car 14 approaches the block 21, the car 15 approaches the block 22, and the car 16 approaches the block 23. If appropriate, the cars make intermediate stops on the way to the respectively assigned block, in order to pick up the further passengers who come from other stories and would like to travel to the block assigned to the respective car. A corresponding assignment of an elevator car is possible on the basis of the destination selection control which is present. After a car has served the block assigned to it, it travels essentially empty to the transfer point at the top story. There, it uses the transfer device 4 to change into the downward-leading shaft 3. In FIG. 1 this case is illustrated for the elevator car 16. The required time up to this point shall be referred to as T1, and is obtained as a total of the time losses for the main stop at the first start position, for the intermediate stops for picking up further passengers, for the exit stops and, if appropriate entry stops in the assigned block and for the travel times for the total upward travel and for the transfer process.

d) Partial Cycle in the Second Shaft:

[0077] After the transfer of a car into the downward-leading shaft 3, the pattern continues correspondingly in the inverse direction. The first car, which has served the top block in an upward direction, that is to say the cars 11 and 14 in the example in FIG. 1, serves the last block again in the downward travel, now the block 23. This last block lies furthest away from a second home position, here at a distance from the second start position which constitutes the stopping point in the top story in the downward-leading shaft 3. For example, the car 14 mainly collects passengers in the block 23, to be more precise at the stopping points of the block 23 when corresponding requests occur. Subsequently, that car which has served the block 22 serves the penultimate block, here again the block 22. Subsequently, the car which has served the block 23, that is to say the cars 13 and 16, in turn serves the block 21 which is closest to the second start position. After its block has been served, the cars travel downward again and travel back to the first start position which forms a critical stopping point at which each of the cars stop. On the way to said position, intermediate stops can be made, in particular in order to let out or pick up passengers. In the illustrated exemplary embodiment, the letting out of the passengers occurs expediently at the lowest stopping point of the downward-leading second shaft 3 before the corresponding car is transferred back to the first start position by means of the transfer device 4. The time required for the downward travel together with stopping and transfer shall be referred to T2.

e) Time Condition for the Specification of Stopping Times:

[0078] After upward travel and downward travel, each car is located again at the location at the critical stopping point, that is to say at the first start position. For this circulation, each car has required the cycle time T=T1+T2. While the times T1 and T2 required for the partial cycles for each car may be different, it is decisive for efficient operation with a high transportation capacity that the entire cycle time T is the same for all the cars. The loss of time, in particular for three intermediate stops, is therefore preferably dimensioned such that in total the cycle time T is not exceeded, or is utilized as far as possible completely, over the entire circulation. If a car were to pass through the cycle too quickly, an additional waiting time could be introduced at a suitable point, for example in the lobby or at some other critical stopping point. Furthermore, in such a case the “empty travel” of the car after serving the primary block can also be used for special travel, special destinations or for further intermediate story traffic, in order to utilize the still remaining time window within the cycle time.

f) Time Offset Between the Cars:

[0079] For a total circulation, each car requires the same cycle time. Each circulation is carried out with a time offset with respect to a circulation of another car. This ensures that no car is impeded by the car travelling ahead. The time offset from one car to the next is in each case on average T/m and must be selected to be long enough to make available sufficient flexibility for intermediate stops during the travel.

[0080] Overall, the exemplary embodiment according to FIG. 1 which is dealt with here is represented by a travel diagram, of which FIG. 2 illustrates a detail. The travel diagram illustrates the position z of all the cars plotted against the time t. The vertical direction in which the stories 6 of the building 5 in FIG. 1 are arranged is denoted by z. The travel diagram f for the car 11 is denoted by f.sub.11, that of the car 12 by f.sub.12, and that of the car 13 by f.sub.13. From the travel diagram f.sub.11 it is clear, for example, that the car 11 makes an intermediate stop on the way to the top block 21. Subsequently, a stopping point in the top block 21 is served. After the transfer into the downward-leading shaft, the car 11 approaches the lowest block 23, in order to serve a stopping point there and subsequently to return to the first start position. The travel diagram f.sub.12 shows that the second car 12 approaches three stopping points of the center block 22 assigned to it, and subsequently changes shaft in order, in turn, to approach a stopping point in the center block and subsequently to return to the first start position. The travel diagram f.sub.13 for the following third car 13 shows that this car approaches two stopping points of the lowest block 23, in order then to move to the transfer device 4 in the top story.

[0081] From FIG. 2 it is apparent that the cycle times T for each of the cars 11, 12 and 13 are the same.

[0082] If there are a plurality of critical parallel stopping points, for example if the transfer devices 4 constitute the critical stopping points, the control method can be adapted in such a way that not only the total cycle time T but also partial times of the partial cycles between two critical stopping points are always the same for all the cars, for example T1 and T2 in the case under consideration here.

[0083] In the text which follows, further embodiments and the advantages of the invention described here will be specified.

[0084] Each block can be assigned one or more cars which primarily serve this block. The number of cars can be defined individually for each block.

[0085] The time requirement which is provided for a main stop, for example in a lobby, and for intermediate stops at any of the stories can be varied, for example depending on the time of day, in order to be able to cope with different traffic situations in an optimum way, for example a long stop in a lobby during morning upward traffic and a short stop in the lobby linked to more time for intermediate stops at off-peak traffic times.

[0086] The control method can easily be parameterized for a given number of m cars and n stories as well as a predicted traffic demand.

[0087] This parameterization can also be carried out in an automated fashion, for example depending on the time of day, or according to measured traffic volume. The easy parameterization also permits the number of cars m to be changed, for example by removing or adding cars during operation.

[0088] The predefined cycle ensures that the available shaft space is always used efficiently by the cars. Furthermore, it is ensured that the cars are distributed approximately uniformly over the shaft space, resulting in uniform utilization of the transfer devices. These devices can therefore be configured for lower transfer speeds than in the case of travel of cars at a random distance from one another.

[0089] The predefined cycle results in an overall more predictable and more uniform traffic of the cars without traffic stoppages owing to mutual impediment. The specified advantages result in a particularly high transportation capacity of the system. The transportation capacity is even close to the theoretical optimum of the system, including a small permitted reserve for the advance planning of the stopping times.

described control method can advantageously be applied to any logistical tasks with a plurality of individually driven or individually movable transport devices in a circulation operation. Such logistical tasks occur, for example, in fabrication devices, or in production systems of, for example, chemical facilities.

LIST OF REFERENCE SYMBOLS

[0090] 1 Transport system, elevator system [0091] 2 First conveyor section, first shaft [0092] 3 Second conveyor section, second shaft [0093] 4 Transfer device [0094] 5 Building [0095] 6 Story [0096] 7 Control device [0097] 11 to 16 Car [0098] 21 to 23 Block [0099] T Cycle time [0100] f Travel diagram [0101] T1, T2 Partial cycle times