Article conveying facility

Abstract

An article transport facility is provided with an article transport vehicle and a control system for controlling the article transport vehicle. An article transport facility is provided with a plurality of receiving conveyors that are transport destinations for articles. The receiving conveyor is capable of holding an article less than or equal to an upper limit number. The control system obtains, for each of the plurality of receiving conveyors, a receivable number obtained by subtracting the holding number and the reservation number from the holding upper limit number, and selects a receiving conveyor that is a conveyance destination of the article on the basis of each receivable number.

Description

Technical Field

[0001] The invention relates to an article conveying device. Background Art

[0002] An article transport facility is used that includes an article transport vehicle that moves along a transport path to transport articles and a control system that controls the article transport vehicle. An example of such an article transport facility is disclosed in Japanese Patent Application Laid-Open No. 2021-76970 (Patent Document 1).

[0003] In the article conveying equipment of Patent Document 1, a control device (control device H) sets a set path (set path 1A) for driving an article conveying vehicle (article conveying vehicle 3) to a conveying destination on a conveying path (travelable path 1) based on the link cost set for each of a plurality of links (links L) constituting the conveying path. In Patent Document 1, the link cost is set so that it becomes larger as the time required to pass through the link becomes longer, and is adjusted so that it becomes larger as the number of other vehicles scheduled to pass through the link increases. Furthermore, the control device calculates the path cost for each of a plurality of candidate paths (candidate paths 1B) from the sum of the link cost and the node cost, and determines the candidate path with the smallest path cost as the set path.

[0004] In Patent Document 1, the destination is first determined, and in order to determine the set path to the destination, a cost calculation is performed that only considers the conditions on the transport path side. However, for example, there may be a situation where a specific destination is determined from a plurality of destination candidates using the same cost calculation. In addition, in this case, when the destination candidates can each hold a plurality of articles at the same time, the conditions of each destination sometimes have a great impact on the overall article transport efficiency of the article transport equipment. For example, even if the path cost to a certain destination candidate is small, when the destination candidate has reached the upper limit of the number of articles that can be held, even if the arrival time is short, a waiting time is generated, and the total transport efficiency sometimes decreases. Summary of the invention

[0005] Therefore, it is desired to realize an article transport facility in which the article transport efficiency of the facility as a whole is unlikely to decrease.

[0006] The article transport equipment involved in the present disclosure is an article transport equipment including an article transport vehicle that moves along a transport path to transport articles and a control system that controls the article transport vehicle. A plurality of receiving conveyors are provided which are destinations for the articles transported by the article transport vehicle. The plurality of receiving conveyors are capable of holding a predetermined number of the above-mentioned articles or less. The aforementioned control system: For each of the plurality of receiving conveyors, the number of receivable items is obtained by subtracting the number of items held by the receiving conveyor and the number of items reserved for determining the number of items to be transported to the receiving conveyor from the upper limit number of items held. The receiving conveyor as the destination of the article is selected based on the receivable number of each of the plurality of receiving conveyors.

[0007] According to this configuration, a receiving conveyor as the destination of the article is selected based on the number of receivables obtained for each of the plurality of receiving conveyors (i.e., the margin up to the upper limit of the number of items held based on the sum of the actual number of items held and the number of items reserved). Therefore, the possibility of a situation in which, even if the article transport vehicle arrives at the receiving conveyor at the destination, the receiving conveyor has to wait until it can actually receive the article can be reduced. Therefore, an article transport facility in which the transport efficiency of the article as a whole is unlikely to decrease can be provided.

[0008] Further features and advantages of the technology according to the present disclosure will become more apparent from the following description of illustrative and non-limiting embodiments described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of an article transport device according to an embodiment. Figure 2 It is a three-dimensional diagram of the article conveying vehicle. Figure 3 It is the block diagram of the control system. Figure 4 is a schematic diagram of a receiving conveyor. Figure 5 It is an explanatory diagram showing a method of calculating the reception cost. Figure 6 This is a flowchart showing the processing procedure of the transport destination determination control. Figure 7 It is a schematic diagram of another embodiment of an article conveying device. DETAILED DESCRIPTION

[0010] The embodiment of the article conveying device is described with reference to the drawings. For example, in order to convey articles A in a semiconductor manufacturing plant, etc., an article conveying device 1 of this embodiment is used. Figure 1 As shown, the article transport facility 1 includes an article transport vehicle 10, a storage unit 20, an interface 30, and a control system 40. The article transport facility 1 of this embodiment includes a plurality of article transport vehicles 10, a plurality of storage units 20, an interface 30 provided for each storage unit 20, and a control system 40.

[0011] The article transport vehicle 10 moves along the transport path 9 to transport the article A. As the article A, for example, a FOUP (Front Opening Unified Pod) that accommodates semiconductor wafers can be exemplified. In addition, in the present embodiment, the transport path 9 of the article transport vehicle 10 is physically formed by a pair of travel rails 91 suspended from the ceiling. That is, the article transport vehicle 10 of the present embodiment is a ceiling transport vehicle that moves along the travel rails 91 suspended from the ceiling.

[0012] like Figure 2 As shown, the article transport vehicle 10 includes a travel portion 11, a main body portion 17, and a transfer portion 19 (see Figure 3 ). The travel unit 11 travels on a pair of travel rails 91. The travel unit 11 includes a vehicle body 12 and a plurality of wheels 14 supported by the vehicle body 12. The wheels 14 roll on a travel surface (in this example, an upper surface) of the travel rails 91. At least one of the plurality of wheels 14 is a driving wheel that is drive-connected to a driving force source (for example, an electric motor such as a servo motor).

[0013] The vehicle body 12 is provided with a reading device 13. The reading device 13 reads the position information stored in the position information storage body 92 provided on the travel track 91. The position information storage body 92 is, for example, a one-dimensional code (barcode) or a two-dimensional code (such as a QR code, etc.), an IC tag, etc. The position information storage body 92 is provided in multiple locations, each of which stores inherent position information. The reading device 13 uses a reading device corresponding to the type of the position information storage body 92, for example, a barcode reader, a QR code reader, an IC tag reader, etc.

[0014] In addition, guide wheels 15 are movably supported in the width direction (a direction perpendicular to the extension direction of the travel rail 91 as the travel direction) on the vehicle body 12. The guide wheels 15 abut against a guide rail 94 provided above the travel rail 91 at a branching portion or a merging portion on the conveying path 9 to guide the branching or merging.

[0015] The main body 17 is suspended and supported from the traveling part 11, and has a transfer part 19 in its internal space. The transfer part 19 can be switched between a holding posture and a holding release posture, and is constructed in a manner that can be raised and lowered. When the transfer part 19 in the holding posture is in the raised position, the main body 17 holds the article A in its internal space. In addition, the transfer part 19 switches between the holding posture and the holding release posture by descending to a predetermined position, and the article A can be delivered (received and delivered).

[0016] The storage unit 20 stores the articles A transported by the article transport vehicle 10. The storage unit 20 of this embodiment is composed of a multi-layer storage rack 21 having a storage rack, a lifting device, and a transfer device. The storage rack is formed in a tower shape and has a plurality of storage units arranged over multiple layers. The lifting device moves up and down along the pillars arranged over each layer. The transfer device is provided on the lifting device and performs transfer of the articles A to and from any storage unit.

[0017] The delivery unit 30 delivers the article A between the article transport vehicle 10 and the storage unit 20. Figure 4 As shown, the delivery section 30 of this embodiment includes a receiving conveyor 31 and a delivering conveyor 38. The receiving conveyor 31 receives the article A from the article transport vehicle 10 and delivers it to the storage section 20. Therefore, the receiving conveyor 31 can be the direct delivery destination of the article A transported by the article transport vehicle 10. The delivering conveyor 38 receives the article A from the storage section 20 and delivers it to the article transport vehicle 10. Therefore, the delivering conveyor 38 can be the direct delivery starting point of the article A transported by the article transport vehicle 10.

[0018] The delivery section 30 is provided one-to-one with respect to each of the plurality of storage sections 20. That is, for each storage section 20 (in this example, the multi-layer storage rack 21), a receiving conveyor 31 and a delivery conveyor 38 are provided in pairs. The plurality of receiving conveyors 31 are receiving conveyors that receive articles A from the article transport vehicle 10 and deliver them to the corresponding storage sections 20, and are functionally equivalent to each other. In addition, the plurality of delivery conveyors 38 are also delivery conveyors that receive articles A from the corresponding storage sections 20 and deliver them to the article transport vehicle 10, and are functionally equivalent to each other.

[0019] The receiving conveyor 31 is formed with a length capable of holding a plurality of articles A at the same time. The receiving conveyor 31 has a receiving portion 32 for receiving articles A from the article transport vehicle 10 and a delivery portion 36 for delivering the received articles A to the storage unit 20. In the present embodiment, the storage unit 20 (in this example, the multi-layer storage rack 21) corresponds to "a device other than the article transport vehicle". In addition, in the present embodiment, the receiving conveyor 31 further has a standby portion 34 between the receiving portion 32 and the delivery portion 36. In the present embodiment, the receiving conveyor 31 has one receiving portion 32, a plurality of (in Figure 4 In the example, there are 3) standby locations 34 and 1 delivery location 36.

[0020] Moreover, the receiving conveyor 31 can simultaneously hold a number of articles A that is less than the upper limit number Nx. Here, the upper limit number Nx is a value determined by the total number of the receiving portion 32, the standby portion 34, and the delivery portion 36, and is "5" (=1+3+1) in this example. In addition, the standby portion 34 may not necessarily be provided, and the receiving portion 32 and the delivery portion 36 may also be shared. Therefore, the upper limit number Nx is an integer greater than 1. However, it is preferred that the receiving portion 32 and the delivery portion 36 are provided separately, and it is preferred that the standby portion 34 is provided to a degree that is not excessive, and the upper limit number Nx is preferably about 3 to 5.

[0021] The delivery conveyor 38 is also formed to have a length capable of holding a plurality of articles A at the same time. Figure 4 Although not specifically indicated as a distinguishing scheme, the delivery conveyor 38 also has a receiving portion for receiving the article A from the storage unit 20, a delivery portion for delivering the received article A to the article transport vehicle 10, and a standby portion between the receiving portion and the delivery portion. The number of articles A that the delivery conveyor 38 can hold at the same time can be the same as the upper limit number Nx of the receiving conveyor 31.

[0022] The receiving conveyor 31 and the delivering conveyor 38 may be, for example, roller conveyors, belt conveyors, plate belt conveyors, etc. The receiving conveyor 31 and the delivering conveyor 38 may be the same type of conveyor or different types of conveyors.

[0023] like Figure 1 As shown, the article transport equipment 1 of this embodiment is further provided with a plurality of processing devices 7. As described above, when the article A is, for example, a FOUP containing semiconductor wafers, the processing device 7 may be a processing device for processing the semiconductor wafers. The processing device 7 is also provided with a support table for delivering and unloading the article A, and the article transport vehicle 10 also delivers and receives the article A between the processing device 7.

[0024] In addition, a conveyor may be used instead of the above-mentioned support table. This conveyor is the same as the receiving conveyor 31 in that it transfers and unloads articles A to and from the article transport vehicle 10. However, this is a conveyor that receives articles A from the article transport vehicle 10 and delivers them to the corresponding processing devices 7. The delivery destination device is different, so in this embodiment, it is considered to be different from the receiving conveyor 31 in terms of function.

[0025] The control system 40 controls the article transport vehicle 10. Figure 3As shown, the control system 40 of this embodiment includes the following: an upper control device 41, which is provided on the equipment side; and a control terminal device 46, which is mounted on each article transport vehicle 10 and can communicate with the upper control device 41. The upper control device 41 and each control terminal device 46 are respectively equipped with a CPU (Central Processing Unit) and other computing devices and RAM (Random Access Memory), ROM (Read Only Memory) and other main storage devices. The functions of the upper control device 41 and each control terminal device 46 are realized by the cooperation of the computing device and the program executed on the computing device.

[0026] The upper control device 41 uniformly controls the movements of the plurality of article transport vehicles 10. The upper control device 41 grasps the current position of each article transport vehicle 10, the transport path (including the destination and the via point) of each article transport vehicle 10, etc., and controls the movements of the plurality of article transport vehicles 10 based on these. In addition, the upper control device 41 also controls the movements of the receiving conveyor 31 and the delivery conveyor 38, the movements of the lifting device and the transfer device of the multi-layer storage rack 21 constituting the storage unit 20, etc.

[0027] In addition, the upper control device 41 includes a cost calculation unit 42, a transportation destination determination unit 43, and a storage unit 44. The cost calculation unit 42 calculates the cost of transportation of the article A by the article transport vehicle 10. The transportation destination determination unit 43 selects a receiving conveyor 31 as a transportation destination of the article A from a plurality of receiving conveyors 31. The storage unit 44 stores information related to the structure of the transport path 9, the attributes of each part, etc. in advance as map information M (map information M).

[0028] In this embodiment, an article A containing an object (e.g., a semiconductor wafer) processed by any processing device 7 is transported to and stored in any of the plurality of storage units 20. At this time, in order to determine to which storage unit 20 the article A is transported (as a prerequisite, to which receiving conveyor 31 the article A is transported), the map information M stored in the storage unit 44 is referred to, and at the same time, the cost calculation unit 42 cooperates with the transport destination determination unit 43.

[0029] If it is decided to receive the article A at any processing device 7 and to transport the article A to any storage unit 20, the cost calculation unit 42 first extracts a plurality of receiving conveyors 31 ( Figure 6 Then, the cost calculation unit 42 first calculates the cost ( Figure 6 In the present embodiment, the cost required to move the article transport vehicle 10 to the candidate receiving conveyor is referred to as the "path cost".

[0030] For example, the map information M includes information on a plurality of links and a plurality of nodes showing the network structure of the transport path 9. Furthermore, each link includes information on the cost (through cost) corresponding to its length, shape, etc., and each node includes information on the cost (through cost) corresponding to, for example, the size of a junction or branch, etc. The path cost is calculated as the sum of the costs of all links and nodes included in the path from the current position of the article transport vehicle 10 to the position of the candidate receiving conveyor.

[0031] The cost of each link and each node is most affected by the cost corresponding to the length of the link (the cost increases as the link length increases), so the path cost generally increases as the moving distance from the article transport vehicle 10 to the candidate receiving conveyor increases. In other words, the path cost generally decreases as the moving distance from the article transport vehicle 10 to the candidate receiving conveyor decreases.

[0032] The route cost may be calculated based on other factors, such as the number of locations on the route to the candidate receiving conveyor where temporary stops are required, the likelihood of congestion, etc., in addition to the travel distance of the article transport vehicle 10 to the candidate receiving conveyor.

[0033] The cost calculation unit 42 then calculates the cost based on the status of each candidate receiving conveyor at that time, more specifically, the cost considering the capacity when newly receiving the article A ( Figure 6 In the present embodiment, the cost based on the status of the candidate receiving conveyor itself is referred to as "receiving cost".

[0034] For example, in Figure 4 Based on the example Figure 5 In the example, the two receiving conveyors 31 corresponding to the two storage units 20 are both extracted as candidate receiving conveyors. As described above, the upper limit number Nx of holding of these two candidate receiving conveyors is "5". The upper limit number Nx of holding of each receiving conveyor 31 is predetermined according to its size (length) and is mastered by the upper control device 41. The cost calculation unit 42 obtains the predetermined upper limit number Nx of holding for each candidate receiving conveyor.

[0035] The number of articles A actually held by the candidate receiving conveyor at that time (hereinafter referred to as the "holding number Nf") may be different for each candidate receiving conveyor. Figure 5In the example, the candidate receiving conveyor on the left holds 2 items A, and its holding number Nf is "2". In contrast, the candidate receiving conveyor on the right holds 4 items A, and its holding number Nf is "4". Figure 5 In the figure, the article A indicated by the solid hatching indicates the article A actually held.

[0036] Furthermore, the cost calculation unit 42 can obtain the number of items Nf held by each candidate receiving conveyor based on information such as the status of each article transport vehicle 10, the status of each receiving conveyor 31, and the status of the lifting device and the transfer device of each multi-layer storage rack 21, which are known to the superior control device 41. Alternatively, an inventory sensor (such as a weight sensor, an infrared sensor, and a camera, etc.) may be provided at each receiving conveyor 31 or its periphery, and the cost calculation unit 42 may obtain the number of items Nf held by each candidate receiving conveyor based on the detection result of the inventory sensor.

[0037] In addition, the number of articles A that the candidate receiving conveyor does not actually hold at that time but is determined to be delivered (hereinafter referred to as the "reservation number Nr") may also be different for each candidate receiving conveyor. Figure 5 In the example, the candidate receiving conveyor on the left has already decided to deliver a new item A, and its reservation number Nr is "1". In contrast, the candidate receiving conveyor on the right has no reservation to deliver a new item A at this time, and its reservation number Nr is "0". Figure 5 In the figure, the article A indicated by the dotted hatching indicates the article A scheduled to be conveyed in the future.

[0038] Furthermore, the cost calculation unit 42 can obtain the number of reservations Nr for each candidate receiving conveyor based on the information on the destination of each article transport vehicle 10 grasped by the host control device 41 .

[0039] The cost calculation unit 42 calculates the number of receivables Ne (Ne = Nx-Nf-Nr) by subtracting the number of holdings Nf and the number of reservations Nr from the upper limit number Nx for each candidate receiving conveyor. The number of receivables Ne can be said to be the number of net spare frames (spare slots) that are not actually held and not reserved at that time. Figure 5 In the example, the number of receivables Ne of the candidate receiving conveyor on the left is "2" which is obtained by subtracting "2" of the holding number Nf and "1" of the reservation number Nr from "5" of the holding upper limit number Nx. On the other hand, the number of receivables Ne of the candidate receiving conveyor on the right is "1" which is obtained by subtracting "4" of the holding number Nf and "0" of the reservation number Nr from "5" of the holding upper limit number Nx.

[0040] Then, the cost calculation unit 42 calculates the receiving cost for each candidate receiving conveyor based on the number of receivables Ne. In this embodiment, the receiving cost increases as the number of receivables Ne decreases. That is, the receiving cost decreases as the number of receivables Ne increases. Figure 5 In the example, the receiving cost of the candidate receiving conveyor on the left side is smaller than the receiving cost of the candidate receiving conveyor on the right side.

[0041] The transport destination determination unit 43 determines the receiving conveyor 31 ( 31 ) that is actually the transport destination of the article A from among a plurality of candidate receiving conveyors based on the route cost and the receiving cost calculated by the cost calculation unit 42. Figure 6 Step #04). The transport destination determination unit 43 combines the route cost and the receiving cost of each candidate receiving conveyor, and determines the candidate receiving conveyor with the smallest total cost as the receiving conveyor 31 of the transport destination.

[0042] In addition, when calculating the total cost, the path cost and the receiving cost can be simply added together, or they can be added together while being weighted to a certain extent. In the latter case, the coefficient can be set in accordance with the required specifications of the article conveying equipment 1. For example, in the case where it is desired to give priority to shortening the moving time from the article conveying vehicle 10 to the receiving conveyor 31 of the conveying destination so as to improve the conveying efficiency, it is sufficient to adjust the path cost coefficient in a relatively large manner. In addition, for example, in the case where it is desired to give priority to balancing the load between multiple receiving conveyors 31 so that the load is not concentrated on a specific receiving conveyor 31, it is sufficient to adjust the receiving cost coefficient in a relatively large manner.

[0043] [Other implementation methods] (1) In the above-mentioned embodiment, the receiving conveyor 31 is mainly assumed to have a configuration in which each of the receiving portion 32 and the delivery portion 36 is provided. However, the configuration is not limited to this. For example, Figure 7 As shown, as a kind of receiving conveyor 31, it can also include a plurality of (in Figure 7In the example of FIG. 2, a multi-receiving conveyor 31M having two receiving locations 32 is provided. Such a multi-receiving conveyor 31M can be used, for example, in a case where the conveying path 9 is branched into the first conveying path 9A and the second conveying path 9B, and can receive articles A from both conveying paths 9A and 9B. The multi-receiving conveyor 31M has: a first receiving location 32A that receives articles A from the article transport vehicle 10 traveling along the first conveying path 9A; a second receiving location 32B that receives articles A from the article transport vehicle 10 traveling along the second conveying path 9B; and a common delivery location 36 that delivers the received articles A to the storage unit 20. In addition, the multi-receiving conveyor 31M has a first waiting location 34A between the first receiving location 32A and the delivery location 36, and a second waiting location 34B between the second receiving location 32B and the first receiving location 32A.

[0044] In such a multi-receiving conveyor 31M, the upper limit number Nx of holding is set for each of the plurality of receiving locations 32 (i.e., for each of the first receiving location 32A and the second receiving location 32B). In the example shown in the figure, the upper limit number Nx of holding of the first receiving location 32A is determined by the total number of the first receiving location 32A, the first waiting location 34A, and the delivery location 36, and the upper limit number Nx of holding of the second receiving location 32B is determined by the total number of the second receiving location 32B and the second waiting location 34B. Therefore, in this example, the upper limit number Nx of holding is "3" regardless of whether it is the first receiving location 32A or the second receiving location 32B.

[0045] (2) In the above-mentioned embodiment, the receiving conveyor 31 and the delivery conveyor 38 are mainly assumed to convey the article A in only one direction. However, the present invention is not limited to such a configuration, and the receiving conveyor 31 and the delivery conveyor 38 may be capable of conveying the article A in two directions. In this case, the receiving conveyor 31 may have the waiting area 34 on both sides of the receiving area 32.

[0046] (3) In the above-mentioned embodiment, the multi-layer storage rack 21 constituting the storage unit 20 is described as an example in which the storage rack is formed in a tower shape. However, the present invention is not limited to such a structure. For example, the multi-layer storage rack 21 may be formed in a rack-type storage rack. In this case, the storage rack 21 may be configured so that a transport vehicle reciprocates on each layer. In addition, the storage unit 20 may be an automatic warehouse equipped with a stacking crane.

[0047] (4) In the above embodiment, the article A transported by the article transport vehicle 10 is a FOUP accommodating semiconductor wafers. However, the present invention is not limited to this configuration, and the transported article A may be any article such as a reticle box or an open cassette.

[0048] (5) The configurations disclosed in the above-mentioned embodiments (including the above-mentioned embodiments and other embodiments; the same applies below) can also be combined and applied with the configurations disclosed in other embodiments as long as no contradiction occurs. Regarding other configurations, the embodiments disclosed in this specification are also illustrative in all aspects and can be appropriately changed within the scope of the present disclosure.

[0049] [Summary of implementation methods] If the above is summarized, it is appropriate that the article transport facility according to the present disclosure includes the following structures.

[0050] An article conveying device is provided, which is an article conveying device comprising an article conveying vehicle that moves along a conveying path to convey articles and a control system that controls the article conveying vehicle. A plurality of receiving conveyors are provided which are destinations for the articles transported by the article transport vehicle. The plurality of receiving conveyors are capable of holding a predetermined number of the above-mentioned articles or less. The aforementioned control system: For each of the plurality of receiving conveyors, the number of receivable items is obtained by subtracting the number of items held by the receiving conveyor and the number of items reserved for determining the number of items to be transported to the receiving conveyor from the upper limit number of items held. The receiving conveyor as the destination of the article is selected based on the receivable number of each of the plurality of receiving conveyors.

[0051] According to this configuration, a receiving conveyor as the destination of the article is selected based on the number of receivables obtained for each of the plurality of receiving conveyors (i.e., the margin up to the upper limit of the number of items held based on the sum of the actual number of items held and the number of items reserved). Therefore, the possibility of a situation in which, even if the article transport vehicle arrives at the receiving conveyor at the destination, the receiving conveyor has to wait until it can actually receive the article can be reduced. Therefore, an article transport facility in which the transport efficiency of the article as a whole is unlikely to decrease can be provided.

[0052] As a solution, it is preferred that The control system comprises a cost calculation unit for calculating the cost of transporting the article by the article transport vehicle. The cost calculation unit reduces the cost for each of the plurality of receiving conveyors at least as the moving distance of the article transport vehicle to the receiving conveyor becomes shorter, and reduces the cost as the number of articles that can be received by the receiving conveyor increases.

[0053] According to this structure, a receiving conveyor that has completed the moving distance of the article transport vehicle is short, or a receiving conveyor that has a large margin to maintain the upper limit number is easily selected as the transport destination of the article. Therefore, the moving time of the article transport vehicle to the receiving conveyor of the transport destination can be suppressed to a short time, thereby improving the transport efficiency of the article, and the load can be balanced among multiple receiving conveyors.

[0054] As a solution, it is preferred that The control system selects the receiving conveyor as the conveyance destination of the article from among the plurality of receiving conveyors that are functionally equivalent.

[0055] According to this configuration, when any one of a plurality of functionally equivalent receiving conveyors can be selected before conveying an article to a destination, an appropriate conveying destination can be selected from among them. Therefore, the conveying efficiency of the article can be improved while conveying the article appropriately.

[0056] As a solution, it is preferred that Each of the plurality of receiving conveyors comprises a receiving portion for receiving the article from the article transport vehicle and a delivery portion for delivering the received article to a device other than the article transport vehicle. The receiving conveyor includes a multi-receiving conveyor having a plurality of the receiving locations. In the multi-receiving conveyor, the upper limit number of holding is set for each of the plurality of receiving locations.

[0057] According to this configuration, when the plurality of receiving conveyors provided by the article transport facility include a multi-receiving conveyor having a plurality of receiving locations, each receiving location can be selected as a candidate for a separate transport destination with an upper limit set. Thus, the selection range of the transport destination can be expanded compared to the actual number of receiving conveyors.

[0058] The article transport facility according to the present disclosure only needs to achieve at least one of the above-mentioned effects. Explanation of symbols

[0059] 1. Goods conveying equipment 9 Conveying path 10 Goods transport vehicle 20 Storage Department (equipment other than the article transport vehicle) 31 Receiving conveyor 31M Multi-receiver Conveyor 32 Receiving site 32A 1st receiving part 32B Second receiving site 36 Delivery Location 40 Control System 42 Cost Calculation Department 43 Delivery destination determination unit A Item Ne is the receivable number.

Claims

1. An article transport device comprising an article transport vehicle that moves along a transport path to transport articles and a control system that controls the article transport vehicle, The article conveying device has the following characteristics: A plurality of receiving conveyors are provided, which are destinations for the articles to be transported by the article transport vehicle. The plurality of receiving conveyors are capable of respectively holding a number of the articles that is less than a predetermined upper limit. The control system: For each of the plurality of receiving conveyors, the number of receivable items is obtained by subtracting the holding number, which is the number of the items held by the receiving conveyor, and the reservation number, which is the number of the items to be transported to the receiving conveyor, from the holding upper limit number. The receiving conveyor as the conveyance destination of the article is selected based on the receivable number of each of the plurality of receiving conveyors.

2. The article conveying device according to claim 1, wherein: The control system includes a cost calculation unit for calculating the cost of transporting the article by the article transport vehicle. The cost calculation unit reduces the cost for each of the plurality of receiving conveyors at least as the moving distance of the article transport vehicle to the receiving conveyor becomes shorter, and reduces the cost as the number of articles that can be received by the receiving conveyor increases.

3. The article conveying device according to claim 1 or 2, wherein: Each of the plurality of receiving conveyors includes a receiving portion for receiving the article from the article transport vehicle and a delivering portion for delivering the received article to a device other than the article transport vehicle. The receiving conveyor includes a multi-receiving conveyor having a plurality of the receiving locations. In the multi-receiving conveyor, the upper limit number of holding is set for each of the plurality of receiving locations.

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