JP2006248690A - Travel control method for a plurality of stacker cranes - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve conveying efficiency in an automated warehouse by shortening a conveyance stand-by time for avoiding interference while avoiding interference between two stacker cranes traveling on the same track. <P>SOLUTION: In a travel control method for a plurality of stacker cranes, two stacker cranes C1, C2 are arranged on the same track R, and travel areas A1, A2 of the respective stacker cranes C1, C2 comprise free travel areas A11, A21 allowing free travel at least without interference of the other stacker crane, and mutual travelable areas A13, A23 for delivering a conveyed object between the stacker cranes C1, C2. Two relay shelves T1, T2 for delivering the conveyed object between the stacker cranes C1, C2 are arranged in the mutual travelable areas A13, A23, and when delivering the conveyed object, the stacker cranes C1, C2 can simultaneously enter the mutual travelable areas A13, A23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plurality of stacker cranes in which at least two stacker cranes are arranged on the same track, and more specifically, a transport standby time for avoiding interference while preventing interference between the stacker cranes. The present invention relates to a traveling control method for a plurality of stacker cranes with a shortened length.

  Conventionally, for example, in an automatic warehouse that can temporarily store and store workpieces containing liquid crystal substrates, the size of the automatic warehouse has increased due to the recent increase in the size of the liquid crystal substrates, and the stacker crane has run. The trajectory is also longer. For this reason, a plurality of stacker cranes are run to efficiently load and unload workpieces. In this case, the following four methods are conceivable as a traveling control method for the plurality of stacker cranes.

  The first method is the method shown in FIG. That is, the stacker cranes C101 and C201 travel on the same track R, and the travel area A101 of the stacker crane C101 and the travel area A201 of the stacker crane C201 almost overlap. That is, each of the stacker cranes C101 and C201 can access the storage shelf H in almost the entire area of the automatic warehouse. In this case, in order to avoid interference between the stacker cranes C101 and C201, when one stacker crane is carrying, the other stacker crane has an end on the track R opposite to the arrangement of the one stacker crane. It is necessary to move to the department and wait.

  The second method is the method shown in FIG. That is, the stacker cranes C101 and C201 travel on the same track R, and the travel area A101 of the stacker crane C101 and the travel area A201 of the stacker crane C201 are completely separated at a substantially central position of the warehouse. . Thereby, each stacker crane C101, C201 can be freely travel controlled without any limitation.

  The third method is the method shown in FIG. That is, the stacker cranes C101 and C201 travel on the same track R, and the travel area A101 of the stacker crane C101 and the travel area A201 of the stacker crane C201 are completely separated so that the stacker cranes do not interfere with each other. Yes. In the method shown in FIG. 8, the transfer machine S is further arranged between the travel area A101 of the stacker crane C101 and the travel area A201 of the stacker crane C201, and the stacker crane is passed through the transfer machine S. The workpiece is transferred between C101 and C201.

The fourth method is the method described in Patent Document 1 shown in FIG. That is, the relay shelf T arranged in a part of the storage shelf H in each row is set as a mutually travelable section (interference area) B in which the two stacker cranes C101 and C201 can travel, and the relay shelf in the interference area B The travel of the stacker cranes C101 and C201 is controlled so as to carry the goods via T.
JP 2004-277166 A

  However, the first method has a problem that the stacker crane is waiting while the other stacker crane is operating, so that the waiting time of the stacker crane is long and the conveyance efficiency is poor.

  Further, in the second method, since workpieces cannot be delivered between the stacker cranes, for example, when workpieces are delivered from the stacker crane C101 to C201, an unillustrated exit port disposed in the travel area A101 of the stacker crane C101. The workpiece is taken out from the automatic warehouse, and the workpiece is transferred to a storage port (not shown) arranged in the traveling area A201 of the stacker crane C201 by using an external transfer facility and delivered to the stacker crane C201. As a result, there is a problem that a transfer facility for transferring between stacker cranes is required outside the automatic warehouse. In addition, since the transfer facility is provided outside the automatic warehouse, there is a problem that the transfer time becomes long.

  Further, in the third method, it is necessary to provide the transfer machine S separately from the stacker crane, which increases the equipment cost of the automatic warehouse, and in order to provide the transfer machine S, the number of storage shelves H is small. There was a problem of fewer.

  In the fourth method, for example, when a workpiece is transferred from the stacker crane C101 to the stacker crane C201, the stacker crane C101 first moves to a position where the workpiece is located, and after the workpiece is taken out, the stacker crane C201 If it is in the interference area B, the work is transported to the relay shelf T after being retracted from the interference area B and stored in the relay shelf T. Next, if the stacker crane C101 is in the interference area B, the stacker crane C201 waits for the stacker crane C101 to retreat from the interference area B, moves to the relay shelf T, takes out the workpiece from the relay shelf T, and reaches the target location. The travel control is such as conveying and storing the work on the shelf. That is, in the workpiece transfer process, only one of the stacker cranes can always enter the interference area B. Therefore, when one stacker crane accesses the relay shelf T, the other stacker crane must always wait until it retracts from the interference area B, and this waiting time has a problem of reducing the transport efficiency of the stacker crane. there were.

  The present invention was devised to solve such problems, and its purpose is to avoid the interference between at least two stacker cranes traveling on the same track while reducing the waiting time for conveyance for avoiding interference. An object of the present invention is to provide a traveling control method for a plurality of stacker cranes which can improve the transport efficiency in an automatic warehouse by shortening.

  In order to achieve the above object, a traveling control method for a plurality of stacker cranes according to the present invention is a traveling control method for a plurality of stacker cranes in which at least two stacker cranes are arranged on the same track. The traveling area is composed of a free traveling area that can travel freely without being interfered by at least another stacker crane, and a mutual traveling area that delivers a transported object between the stacker cranes. It has a configuration in which a plurality of relay shelves for delivering a conveyed product between stacker cranes are arranged. And at the time of delivery of the transported goods, each stacker crane is controlled so that a plurality of stacker cranes corresponding to the number of the relay shelves can simultaneously enter the mutually travelable area, thereby passing through the relay shelves. It is configured to deliver the conveyed product.

  That is, at the time of delivery, a plurality of stacker cranes corresponding to the number of relay shelves are allowed to enter the mutual travelable area at the same time, so that one stacker crane is retracted from the mutual travelable area. A state where the crane is waiting can be avoided, and as a result, the waiting time of the stacker crane is shortened, so that the transport efficiency of the stacker crane can be improved.

  As a specific travel control method, when storing the goods on the relay shelf for delivery, a plurality of stacker cranes corresponding to the number of relay shelves can be entered simultaneously into the mutually travelable area, When taking out, each stacker crane is controlled so that only one applicable stacker crane can enter the mutually travelable area.

  In other words, the delivery process of the transported goods is divided into a first half process in which one stacker crane stores the transported goods on the relay shelf and a second half process in which the other stacker crane picks up the transported goods from the relay shelf for delivery. be able to. In the present invention, when the first half of the process is instructed to two stacker cranes at the same time, for example, both stacker cranes are allowed to enter the mutual travelable area at the same time, and the two stacker cranes arranged in the mutual travelable area are used. Each stacker crane can store a transported object at each of the relay shelves.

  To enable such stacker crane travel control in the first half of the process, the two relay shelves do not interfere with each other even when two corresponding stacker cranes enter the mutually travelable area at the same time. It is necessary to keep the distance.

  As a result, in the first half of the process, one stacker crane enters the mutually travelable area from the free-running area and reaches the first relay rack (here, the first relay rack), and the other stacker crane Even if it enters the area where mutual travel is possible from the free-running area and reaches the first relay shelf (here, the second relay shelf), the distance between the two relay shelves is as shown above. Since the distance between the two stacker cranes is maintained at a distance that does not interfere with each other, the two stacker cranes do not interfere with each other within the mutually travelable area.

  On the other hand, in the latter half of the process, one stacker crane enters the mutually travelable area, passes through the first relay shelf (first relay shelf), and travels to the second relay shelf (second relay shelf). Similarly, the other stacker crane also enters the mutually travelable area, passes through the first relay shelf (second relay shelf), and passes through the second relay shelf (first relay shelf). ) And stop, so if they enter the mutually travelable area at the same time, they will interfere with each other. Therefore, in the latter half of the process, only one stacker crane that takes out the conveyed product from the relay shelf can enter the mutual travelable area.

  According to the traveling control method for a plurality of stacker cranes of the present invention, at the time of delivery, a plurality of stacker cranes corresponding to the number of relay shelves are allowed to enter the mutually travelable area at the same time. Thus, it is possible to avoid a situation in which the other stacker crane waits until the vehicle is retracted from the mutual travelable area. As a result, it is possible to reduce the transport waiting time when delivering the transported goods between the stacker cranes via the relay shelf, and the transport efficiency can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  This embodiment demonstrates the case where the traveling control method of the multi-stacker crane concerning this invention is applied to an automatic warehouse. Moreover, the case where there are two stacker cranes as one form of the automatic warehouse will be described. Furthermore, as the conveyed product, for example, an in-process product (liquid crystal substrate, etc.) that is an intermediate product before being processed into a final product is conceivable, but this is not limited to such an in-process product. In the embodiment, the conveyed product will be described as a workpiece.

  As shown in FIG. 1, two stacker cranes C <b> 1 and C <b> 2 are provided in the automatic warehouse 1 and can travel on the same track R. A plurality of storage shelves H1, H2, and H3 are arranged on both sides of the track R along the track R, and the storage shelves H1, H2, and H3 can be accessed from the stacker cranes C1 and C2. It is like that.

  A warehousing port I and a warehousing port O are provided at the end of the automatic warehouse 1 (the left end in the present embodiment), and are connected to a transport facility disposed outside the automatic warehouse 1 (not shown). In the central part of the automatic warehouse 1, two relay shelves T1 and T2 are arranged in this embodiment. The relay shelves T1 and T2 are fixed so that when one stacker crane C1 is accessing one relay shelf T1, the other stacker crane C2 can access the other relay shelf T2. The distance L1 is maintained. Here, the fixed distance L1 is when the width of the stacker cranes C1 and C2 (the length in the direction along the track R) is larger than the width of the relay shelves T1 and T2 (the length in the direction along the track R). The stacker crane C1 is located in front of the relay shelf T1 (specifically, the workpiece storage position and the take-out position) and accesses the relay shelf T1, and the stacker crane C2 is in front of the relay shelf T2 (specifically, The distance is such that at least both stacker cranes C1 and C2 do not interfere with each other when accessing the relay shelf T2 at the workpiece storage position and the take-out position. However, when the width of the stacker crane is smaller than the width of the relay shelf, this fixed distance may be zero, that is, the relay shelves T1 and T2 may be arranged adjacent to each other. In the present embodiment, as shown in FIG. 1, the stacker cranes C1 and C2 are arranged with a certain distance L1 because the width of the stacker cranes C1 and C2 is larger than the width of the relay shelves T1 and T2.

  Further, in the present embodiment, the traveling area A1 of the stacker crane C1 is a free-running area A11 that can travel freely without being interfered with the other stacker crane C2, and the mutual traveling that transfers the transported goods between the stacker cranes. It is divided into possible areas A13, and relay shelves T1 and T2 are arranged at both ends of the mutually travelable area A13. In addition, when the stacker crane C2 is traveling and accessing to the front of the relay shelf T1 in the mutual travelable area A13 for transferring workpieces between the free travel area A11 and the mutual travelable area A13. An interference area A12 for avoiding interference with the stacker crane C2 is provided. This interference area A12 need not be provided when the width of the stacker crane is smaller than the width of the relay shelf as described above.

  Similarly, the traveling area A2 of the stacker crane C2 also includes a free traveling area A21 that can freely travel without being interfered with the other stacker crane C1, and a mutually travelable area A23 that delivers a transported object between the stacker cranes ( The stacker crane C1 travels to the front of the relay shelf T2 between the free travel area A21 and the mutual travel area A23 for transferring workpieces. An interference area A22 is provided for avoiding interference with the stacker crane C1 during access. This interference area A22 need not be provided when the stacker crane width is smaller than the width of the relay shelf as described above.

  More specifically, since the stacker crane C1 is disposed on the left side in the automatic warehouse 1, the traveling area A1 of the stacker crane C1 includes the left end (the entry port I and the exit port O of the automatic warehouse 1). From the left edge of the automatic warehouse 1 to the boundary position with the interference area A12. The free running area A11 is an area from the left edge of the automatic warehouse 1 to the boundary position with the interference area A12. It is. Similarly, the free-running area A21 of the stacker crane C2 is disposed at the left end in the mutual travelable area A23 from the right end of the automatic warehouse 1 because the stacker crane C2 is disposed on the right side in the automatic warehouse 1. This is an area up to the relay shelf T1, and the free-running area A21 is an area from the right end of the automatic warehouse 1 to the boundary position with the interference area A22.

  In the configuration of the automatic warehouse 1 shown in FIG. 1, the concept of the travel areas A1, A2 of the stacker cranes C1, C2 is divided into free travel areas A11, A21, interference areas A12, A22, and mutually travelable areas A13, A23. Although the areas are defined so as not to overlap each other, the concept of the traveling areas A1 and A2 can be defined as follows.

  That is, as shown in FIG. 2, the traveling area A1 of the stacker crane C1 is from the end opposite to the other stacker crane C2 (in this embodiment, the left end of the automatic warehouse 1) to the relay shelf T2. The travel area A2 of the stacker crane C2 is an area from the end opposite to the other stacker crane C1 (in this embodiment, the right end of the automatic warehouse 1) to the relay shelf T1. The travel areas A1 and A2 are the same as the travel areas A1 and A2 shown in FIG.

  Then, the area between the relay shelf T1 and the relay shelf T2 is defined as the mutually travelable areas A16 and A26 of both stacker cranes C1 and C2, and the stacker crane C1 is connected to the relay shelf T2 in the mutually travelable areas A16 and A26. Area A27 where the other stacker crane C2 cannot access due to interference when accessing, and area A17 where the other stacker crane C1 cannot access due to interference when the stacker crane C2 is accessing the relay shelf T1 And the areas including the interference areas A18 and A28. Further, in the traveling area L1 of the stacker crane C1, the portion from the end opposite to the stacker crane C2 (the left end of the automatic warehouse 1) to the relay shelf T1 is defined as the normal traveling area A15 of the stacker crane C1, Of the travel area L2 of the stacker crane C2, the portion from the end opposite to the stacker crane C1 (the right end of the automatic warehouse 1) to the relay shelf T1 is defined as a normal travel area A25 of the stacker crane C2.

  That is, the normal travel areas A15 and A25 are not only the range in which the stacker crane travels to execute the normal transport process for storing the work in the storage shelf H1, but also for the transfer of the work in the work transfer process. This is an area including the range in which the stacker crane travels in order to execute the process up to the first half of storing the work in the corresponding relay shelf with the stacker crane. By introducing such a concept of the normal traveling areas A15 and A25, it is possible to reliably and easily avoid interference between the stacker cranes C1 and C2, as will be described later.

  Incidentally, the normal travel area A15 shown in FIG. 2 is changed from the free travel area A11 shown in FIG. 1 to the interference area A12 and the subsequent area to the right end of the relay shelf T1 (more precisely, the stacker crane C1 is used for delivery). The normal travel area A25 corresponds to the free travel area A21 shown in FIG. 1 in the interference area A22 and the left end of the relay shelf T2 that follows the normal travel area A21. (Accurately, the area until the stacker crane C2 reaches the front position of the relay shelf T2 for delivery) is added. Further, the interference area A18 (A28) shown in FIG. 2 corresponds to an area obtained by adding the interference areas A12 and A22 to the mutual travelable area A13 (A23) shown in FIG.

  FIG. 3 is a schematic configuration diagram of the entire control system for realizing the traveling control method for a plurality of stacker cranes of the present invention in the automatic warehouse 1 having the above-described configuration.

  When a transport instruction is given from the central control system 2, the automatic warehouse control device 3 takes into consideration the transport priority, the current position and destination of each stacker crane, and the stacker crane, relay rack, and storage rack to be used. And a conveyance instruction is given to the stacker crane control device 4 (4a, 4b). The stacker crane control device 4 moves to the workpiece transfer source, removes the workpiece from the shelf, and transfers the workpiece while performing an interference avoidance operation on the stacker crane based on the transfer instruction from the automatic warehouse control device 3. A series of operations such as moving forward and storing the work on the shelf are performed. The storage memory 5 (5a, 5b) stores the current position and destination of the stacker crane.

  For example, when the central control system 2 gives the automatic warehouse control device 3 a transfer instruction from the warehousing port I to the storage shelf H3, the automatic warehouse control device 3 first determines and reserves a relay shelf to be used. To do. For example, when a shelf in the relay shelf T1 is used, a transport instruction from the warehousing port I to the reserved shelf in the relay shelf T1 is given to the stacker crane control device 4a of the stacker crane C1. The stacker crane control device 4a sets the destination in the storage memory 5a of the stacker crane C1, then instructs the stacker crane C1 to move to the destination, and updates the current position in the storage memory 5a after the movement is completed. At the same time, clear the destination. Further, a transfer completion signal is returned to the automatic warehouse control device 3.

  The automatic warehouse control device 3 that has received this transfer completion signal determines and reserves a storage shelf to be used. And the conveyance instruction | indication from the relay shelf T1 to the reserved shelf of the storage shelf H3 is given with respect to the stacker crane control apparatus 4b of the stacker crane C2.

  The stacker crane control device 4b that has received this transport instruction sets the destination of the storage memory 5b of the stacker crane C2, and then instructs the stacker crane C2 to move to the destination. After the movement is completed, the storage memory 5b Update the current location of and clear the destination. Further, a transfer completion signal is returned to the automatic warehouse control device 3.

  The automatic warehouse control device 3 that has received this transfer completion signal returns a completion signal for the transfer instruction to the central control system 2.

  Next, a travel control method of the stacker crane C1 will be described with reference to an operation flowchart shown in FIG. However, the case where the concept shown in FIG. 2 is used as the concept of the traveling area of the stacker cranes C1 and C2 will be described here.

  In step S11, it is confirmed whether or not there is a transport instruction for the stacker crane C1, and if there is a transport instruction, the process proceeds to step S21, and if not, the process proceeds to step S12.

  In step S12, it is determined whether or not the current position of the stacker crane C1 is within the interference area A18. If it is within the interference area A18, the process returns to step S13, and if not, the process returns to step S11.

  In step S13, in order to retract the stacker crane C1 out of the interference area A18, a retractable position is set as the movement destination of the storage memory 5a of the stacker crane C1.

  In step S14, the stacker crane C1 is moved to the destination.

  In step S15, the current position is updated and the destination is cleared in the storage memory 5a of the stacker crane C1.

  On the other hand, in step S21, the position of the conveyance source instructed from the automatic warehouse control device 3 is stored in the movement destination of the storage memory 5a of the stacker crane C1.

  In step S22, it is determined whether or not the current position and the movement destination stored in the storage memory 5a of the stacker crane C1 are within the interference area A18. If both are outside the interference area A18, the process proceeds to step S26. If so, the process proceeds to step S23.

  In step S23, it is determined whether or not the current position and the moving destination stored in the storage memory 5a of the stacker crane C1 are within the normal travel area A15. If both are within the normal travel area A15, the process proceeds to step S24. Otherwise, the process proceeds to step S25.

  In step S24, it is determined whether or not the current position and the movement destination stored in the storage memory 5b of the stacker crane C2 are within the normal travel area A25. If both are within the normal travel area A25, the process proceeds to step S26. Otherwise, the process returns to step S24 and waits until the condition of step S24 is satisfied.

  On the other hand, in step S25, it is determined whether or not the current position and the movement destination stored in the storage memory 5b of the stacker crane C2 are outside the interference area A28. If both are outside the interference area A28, the process proceeds to step S26. Otherwise, the process returns to step S25 and waits until the condition of step S25 is satisfied.

  On the other hand, in step S26, the stacker crane C1 is moved to the destination.

  In step S27, the current position is updated and the destination is cleared in the storage memory 5a of the stacker crane C1.

  In step S <b> 28, the stacker crane C <b> 1 takes out the workpiece from the storage shelf at the storage port I, the storage shelf H <b> 1, or the relay shelf T <b> 2 and holds it on the stacker crane C <b> 1.

  In step S31, the position of the conveyance destination instructed by the automatic warehouse control device 3 is stored in the movement destination of the storage memory 5a of the stacker crane C1.

  In step S32, it is determined whether or not the current position and the movement destination stored in the storage memory 5a of the stacker crane C1 are within the interference area A18. If both are outside the interference area A18, the process proceeds to step S36. If so, the process proceeds to step S33.

  In step S33, it is determined whether or not the current position and the movement destination stored in the storage memory 5a of the stacker crane C1 are within the normal travel area A15. If both are within the normal travel area A15, the process proceeds to step S34. Otherwise, the process proceeds to step S35.

  In step S34, it is determined whether or not the current position and the movement destination stored in the storage memory 5b of the stacker crane C2 are within the normal travel area A25. If both are within the normal travel area A25, the process proceeds to step S36. Otherwise, the process returns to step S34 and waits until the condition of step S34 is satisfied.

  In step S35, it is determined whether or not the current position and the movement destination stored in the storage memory 5b of the stacker crane C2 are outside the interference area A28. If both are outside the interference area A18, the process proceeds to step S36. If not, the process returns to step S35 and waits until the condition of step S35 is satisfied.

  On the other hand, in step S36, the stacker crane C1 is moved to the destination.

  In step S37, the current position is updated and the destination is cleared in the storage memory 5a of the stacker crane C1.

  In step S38, the work held by the stacker crane C1 is stored in the movement destination shelf.

  Next, an operation timing chart shown in FIGS. 5A and 5B will be described with respect to the embodiment in the case where the transfer request from the shelf 3 to the shelf 30 and the transfer request from the shelf 25 to the shelf 1 are continuously issued. The description will be given with reference. However, here, in order to clarify the difference between the conventional traveling control method and the traveling control method according to the present invention, first, referring to the operation timing chart shown in FIG. 5A, the conventional example shown in FIG. The traveling control method of the present invention will be described with reference to the operation timing chart shown in FIG. 5B.

<Description of conventional traveling control method>
First, in response to a transport request from the shelf 3 to the shelf 30, a transport instruction from the shelf 3 to the shelf 15 in the relay shelf T is issued to the stacker crane C2, so the stacker crane C2 moves to the shelf 3, The work is taken out from the shelf 3 (process 11), transferred to the shelf 15 (process 12), and the work is stored in the shelf 15 (process 13). At this time, a transport request from the shelf 15 to the shelf 30 is generated.

  Further, in response to a transport request from the shelf 25 to the shelf 1, since a transport instruction from the shelf 25 to the shelf 16 in the relay shelf T is issued to the stacker crane C1, the stacker crane C1 moves to the shelf 25 ( Process 21), the work is taken out from the shelf 25 (process 22). Thereafter, the next transport destination is the shelf 16, but the shelf 16 is in the interference area B and the stacker crane C2 is in the interference area B, so that the stacker crane C2 waits until it goes out of the interference area A28. (Processing 23).

  On the other hand, when the transport from the shelf 3 to the shelf 15 is completed, the stacker crane C2 retreats out of the interference area B if there is no next transport instruction (process 14). At this time, since there is no next transport instruction to the stacker crane C2, the system waits until the instruction is given (process 15).

  On the other hand, when the stacker crane C2 retreats out of the interference area B, the stacker crane C1 conveys the workpiece to the shelf 16 (process 24) and stores it on the shelf 16 (process 25). At this time, a transport request from the shelf 16 to the shelf 1 is generated.

  Next, the stacker crane C1 receives a transport instruction from the shelf 15 to the shelf 30, moves to the shelf 15 (process 25), takes out the workpiece from the shelf 15 (process 26), and transports it to the shelf 30 (process). 27) and store in the shelf 30 (process 28).

  On the other hand, the stacker crane C2 receives a conveyance instruction from the shelf 16 to the shelf 1 and tries to move to the shelf 16. However, since the shelf 16 is in the interference area B, the stacker crane C1 is retracted outside the interference area B. Wait for When the stacker crane C1 arrives at the shelf 30, the stacker crane C2 moves to the shelf 16 (process 16), takes out the workpiece from the shelf 16 (process 17), transports it to the shelf 1 (process 18), and stores it in the shelf 1. (Process 19).

<Description of Travel Control Method of the Present Invention>
First, in response to a transfer request from the shelf 3 to the shelf 30, a transfer instruction from the shelf 3 to the shelf 14 is issued to the stacker crane C2, so the stacker crane C2 moves to the shelf 3 and takes out the workpiece from the shelf 3 ( Process 31), transport to shelf 14 (process 32), and store work on shelf 14 (process 33). At this time, a transport request from the shelf 14 to the shelf 30 is generated. Thereafter, since there is no conveyance instruction to the stacker crane C2, the stacker crane C2 retreats out of the interference area A28 (process 34).

  On the other hand, in response to a transfer request from the shelf 25 to the shelf 1, the stacker crane C1 is instructed to transfer from the shelf 25 to the shelf 17, so that the stacker crane C1 moves to the shelf 25 (process 41), and the workpiece is transferred from the shelf 25 to the workpiece. Is taken out (process 42), conveyed to the shelf 17 (process 43), and the work is stored in the shelf 17 (process 44). At this time, the stacker crane C1 and the stacker crane C2 are simultaneously in the interference area A18 (A28).

  Next, the stacker crane C1 receives a transport instruction from the shelf 14 to the shelf 30, moves to the shelf 14 (process 45), takes out the workpiece from the shelf 14 (process 46), and transports it to the shelf 30 (process 47). ), The work is stored in the shelf 30 (process 48).

  On the other hand, the stacker crane C2 is in the stacking crane C1 while the stacker crane C1 is in the interference area A18 because the shelf 17 is outside the normal travel area A25 even if the conveyance instruction from the shelf 17 to the shelf 1 is issued. Is waiting to move out of the interference area A18 (process 35). When the stacker crane C1 leaves the interference area A18 and arrives at the shelf 30, the stacker crane C2 moves to the shelf 17 (process 36), takes out the workpiece from the shelf 17 (process 37), and transports it to the shelf 1 (process). 38) The work is stored in the shelf 1 (process 39).

  As described above, according to the traveling control method of the present invention, even when the conveyance between the stacker cranes overlaps, in the process 44 and the process 33 which are the first half of the workpiece transfer process, the adjacent stacker cranes C1 are used. , C2 can access the relay shelves T1 and T2 at the same time, so that the transport waiting time for avoiding interference is reduced and transport efficiency is improved. In the example shown in FIG. 5B, the waiting time t1 (process 23) in FIG. 5A is reduced.

  In the above embodiment, the case where the traveling control method for a plurality of stacker cranes according to the present invention is applied to an automatic warehouse has been described. However, the present invention provides delivery between two or more transport vehicles traveling on the same track. This is a traveling control method for performing efficiently, and can be applied not only to automatic warehouses but also to delivery of workpieces between a plurality of automated guided vehicles.

It is a schematic plan view which shows an example of the automatic warehouse which applies the traveling control method of the multiple stacker crane of this invention, and is explanatory drawing which shows an example of the area division of the traveling area of a stacker crane. It is a schematic plan view which shows an example of the automatic warehouse which applies the traveling control method of the multiple stacker crane of this invention, and is explanatory drawing which shows the other example of the area division of the traveling area of a stacker crane. It is a schematic block diagram of the whole control system for implement | achieving the traveling control method of the multi-stacker crane of this invention. It is an operation | movement flowchart explaining the traveling control method of the stacker crane C1. The operation | movement timing chart when the conveyance request | requirement is continuously issued to two stacker cranes is shown, (a) is the operation | movement timing chart according to the traveling control method of a prior art example, (b) is the traveling control method concerning this invention. It is the operation | movement timing chart according to this. It is a top view of the automatic warehouse of a prior art example. It is a top view of the automatic warehouse of a prior art example. It is a top view of the automatic warehouse of a prior art example. It is a top view of the automatic warehouse of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic warehouse 2 Central control system 3 Automatic warehouse control apparatus 4 (4a, 4b) Stacker crane control apparatus 5 (5a, 5b) Storage memory C1, C2 Stacker crane R Track of stacker crane I Inlet port O Outlet port H1, H2, H3 Storage shelf T1, T2 Relay shelf A1, A2 Travel area A11, A21 Free travel area A12, A22 Interference area A13, A23 Mutual travel area A15, A25 Normal travel area A16, A26 Mutual travel area A18, A28 Interference area

Claims (3)

A travel control method for a plurality of stacker cranes in which at least two stacker cranes are arranged on the same track,
The traveling area of each stacker crane includes at least a free traveling area that can freely travel without being interfered by other stacker cranes, and an area that allows mutual transportation between the stacker cranes, and the mutual traveling. In the possible area, there are multiple relay shelves that deliver the transported goods between stacker cranes,
At the time of delivery of the transported goods, the transported goods via the relay shelves are controlled by controlling the stacker cranes so that a plurality of stacker cranes corresponding to the number of the relay shelves can enter the mutual travelable area simultaneously. The traveling control method for a plurality of stacker cranes, characterized in that   When storing the transported goods in the relay shelf for delivery, a plurality of stacker cranes corresponding to the number of the relay shelves are allowed to enter the mutual travelable area at the same time, and when removing the transported goods from the relay shelf, 2. The traveling control method for a plurality of stacker cranes according to claim 1, wherein each stacker crane is controlled so that only one stacker crane to be moved can enter the mutually travelable area. 3. The plurality of relay shelves are arranged at a distance that does not interfere with each other even when a plurality of corresponding stacker cranes enter the mutually travelable area at the same time. A traveling control method for a plurality of stacker cranes according to claim 1.

Images