Article conveyance facility

Abstract

To achieve conveyance of an article having high rationality.SOLUTION: A control system executes selection processing for calculating an evaluation cost Cx of respective conveyance vehicles 1 by using a cost which is a value about a factor that affects a movement time of the conveyance vehicle 1 and becomes larger as the movement time becomes long, and selecting, as a target conveyance vehicle 1, the conveyance vehicle 1 having the smallest evaluation cost Cx when the target conveyance vehicle 1 to perform conveyance processing is selected from among the plurality of conveyance vehicles 1 holding no articles. In the selection processing when a specific holding part is made to be a conveyance source F, the evaluation cost Cx is calculated on the basis of both a reception cost Cr corresponding to a movement time from a current position P of the conveyance vehicle 1 to the conveyance source F and a delivery cost Cg corresponding to a movement time from the conveyance source F of the conveyance vehicle 1 to a conveyance destination T.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an item transport facility that includes a plurality of transport vehicles that move along a predetermined travel path to transport items, and a control system that causes the transport vehicles to perform a transport process in which the source and destination of the items are specified. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open Publication No. 2020-66499 (Patent Document 1) discloses a transport system used in a factory that manufactures semiconductor products. In such a transport system, transport vehicles transport items between processes to perform various processes on the items. Generally, based on a transport command issued by a system controller that manages the system, the transport vehicle picks up a specified item at its source and transports the item to its specified destination. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-66499 Summary of the Invention [Problem to be solved by the invention]

[0004] When selecting a transport vehicle to transport an item from among multiple transport vehicles, the transport vehicle closest to the location where the item is stored (the source of the transport) is often selected in order to transport the item rationally from the perspective of transport time, etc. However, when the route structure is complex or there are restrictions on the movement of the transport vehicle along the route, there may be multiple routes for the transport vehicle to reach the destination after receiving the item, i.e., multiple routes from the source of the transport vehicle to the destination. Therefore, if the distance between the source of the transport vehicle and the transport vehicle is used solely as a selection criterion for selecting a transport vehicle to transport the item, it may not be possible to transport the item rationally.

[0005] In view of the above circumstances, there is a demand for an article transport facility that can realize highly efficient article transport. [Means for solving the problem]

[0006] An article transport facility comprising: a plurality of transport vehicles that move along a predetermined travel path to transport articles; and a control system that causes the transport vehicles to perform a transport process in which a source and a destination of the article are specified, an article holding unit capable of holding the article and allowing the transport vehicle to hand over the article is disposed at a plurality of locations along the movement path; at least one of the plurality of article holding units is a specific holding unit that can receive and deliver the article from the transport vehicle located in any of a plurality of specific sections on the movement route; the control system is configured to execute a selection process in which, when selecting a target transport vehicle that is a transport vehicle to perform the transport process from among a plurality of transport vehicles that are not holding the item, the control system calculates an evaluation cost of each transport vehicle using a cost that is a value for a factor that affects a travel time of the transport vehicle and that increases as the travel time becomes longer, and selects the transport vehicle with the smallest evaluation cost as the target transport vehicle; In the selection process when the specified holding unit is the source of transport, the evaluation cost is calculated based on both the receiving cost, which is the cost corresponding to the travel time of the transport vehicle from the current location to the source of transport, and the delivery cost, which is the cost corresponding to the travel time of the transport vehicle from the source of transport to the destination.

[0007] According to this configuration, when the specific holding unit is set as the origin of a transport vehicle, a target transport vehicle to perform the transport process can be selected based on both the cost corresponding to the travel time from the current location of the transport vehicle to the origin and the cost corresponding to the travel time from the origin to the destination of the transport vehicle. In other words, the situation after the transport vehicle receives the item at the origin can also be used as a criterion for selecting the target transport vehicle. Therefore, according to this configuration, it is possible to realize highly rational transport of items.

[0008] Further features and advantages of the techniques according to the present disclosure will become more apparent from the following description of exemplary and non-limiting embodiments, which proceeds with reference to the drawings. [Brief explanation of the drawings]

[0009] [Figure 1] Plan view of the goods transport facility [Figure 2] Front view showing the article holding portion [Figure 3] Front view showing the specific holding part [Figure 4] An explanatory diagram conceptually showing receiving costs and delivery costs [Figure 5] FIG. 10 is an explanatory diagram showing the evaluation cost calculated for each transport vehicle. [Figure 6] A diagram showing a comparison example of the evaluation costs of transport vehicles A and B. [Figure 7] FIG. 10 shows another example of a specific section DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of an article transport facility will be described with reference to the drawings.

[0011] As shown in Figure 1, the item conveying equipment 100 includes a plurality of transport vehicles 1 that move along a predetermined travel path 9 to convey items W (see Figures 2 and 3), and a control system 2 that causes the transport vehicles 1 to perform a transport process in which the origin F and destination T of the items W are specified.

[0012] In this embodiment, the movement route 9 is set so that the movement direction of the transport vehicle 1 is fixed. In other words, the movement route 9 is a one-way route, and the transport vehicle 1 cannot travel in the reverse direction.

[0013] 2 and 3, in this embodiment, the moving path 9 is set at a position spaced above the floor surface. For example, the moving path 9 is configured using rails 90 provided near the ceiling. The transport vehicle 1 is configured as a so-called ceiling transport vehicle, and travels on the rails 90 along the moving path 9.

[0014] There are various types of articles W that can be handled by article transport equipment 100. In this embodiment, article transport equipment 100 is used in a semiconductor manufacturing factory. Therefore, the articles W include substrate storage containers (so-called FOUPs: Front Opening Unified Pods) that store substrates (wafers, panels, etc.), reticle storage containers (so-called reticle pods) that store reticles, etc. In this case, transport vehicle 1 transports articles W such as substrate storage containers and reticle storage containers along movement path 9 between each process.

[0015] As shown in FIG. 1, article holders 3 capable of holding articles W and allowing the transport vehicle 1 to receive and deliver the articles W are arranged at a plurality of locations along the travel route 9.

[0016] 2, in this embodiment, the article holding unit 3 includes a load port arranged adjacent to a processing device 30 that performs processing on the article W. "Processing on the article W" means processing on an object (substrate or reticle) contained in the article W as a container. The processing device 30 performs various processes such as thin film formation, photolithography, and etching.

[0017] The transport vehicle 1 receives from the item holding section 3 an item W that has been processed by the processing device 30, or delivers to the item holding section 3 an item W that has not been processed by the processing device 30. The transport vehicle 1 is equipped with a gripping section 10 that is configured to be able to grip the item W, and is configured to transfer the item W between the transport vehicle 1 and the item holding section 3 using the gripping section 10.

[0018] In the illustrated example, the load port serving as the article holder 3 is positioned below the travel path 9 of the transport vehicle 1. The transport vehicle 1 transfers the article W between itself and the article holder 3 by raising and lowering the gripper 10.

[0019] 2, when the article holder 3 is not positioned directly below the travel path 9 but is positioned laterally offset from the travel path 9, the transport vehicle 1 slides the gripper 10 laterally from the carriage body to position the gripper 10 directly above the article holder 3. The transport vehicle 1 then raises and lowers the gripper 10 to transfer the article W between it and the article holder 3.

[0020] Furthermore, due to the structure of the article holder 3, there may be restrictions on the orientation of the article W placed in the article holder 3. In such cases, the transport vehicle 1 changes the orientation of the article W held by the gripper 10 by rotating the gripper 10 about the vertical axis. This allows the orientation of the article W to be properly oriented relative to the article holder 3.

[0021] As described above, in this embodiment, the transport vehicle 1 is equipped with a slide mechanism for sliding the gripper 10, a lifting mechanism for raising and lowering the gripper 10, and a turning mechanism for turning the gripper 10. When an item W is transferred, the time required for the transfer operation varies depending on whether the gripper 10 is slid, raised or lowered, or turned. The above-described transfer operation can also be referred to as a "transfer operation."

[0022] As shown in Figure 1, at least one of the multiple item holding units 3 is a specific holding unit 3S that can receive and deliver an item W from a transport vehicle 1 located in any of multiple specific sections Z on the travel route 9.

[0023] The multiple specific sections Z include a first specific section Z1 and a second specific section Z2 that are arranged parallel to each other. "Arranged parallel to each other" means that the first specific section Z1 and the second specific section Z2 are arranged side by side in a manner other than being continuously lined up along the extension direction of the movement path 9. Therefore, the first specific section Z1 and the second specific section Z2 do not need to be arranged parallel to each other. In this example, the first specific section Z1 and the second specific section Z2 are arranged side by side on the left and right.

[0024] In this embodiment, the movement direction of the transport vehicle 1 permitted in the first specific section Z1 and the movement direction of the transport vehicle 1 permitted in the second specific section Z2 are set to be different from each other. In the example shown in Fig. 1, the movement direction of the transport vehicle 1 in the first specific section Z1 is permitted only downward in the figure. The movement direction of the transport vehicle 1 in the second specific section Z2 is permitted only upward in the figure.

[0025] In this way, the first specific section Z1 and the second specific section Z2 are arranged parallel to each other and are sections in which the permitted movement direction of the transport vehicle 1 is different. However, when viewed as the movement route 9 as a whole, the first specific section Z1 and the second specific section Z2 are connected via a connecting section so that the transport vehicle 1 can move. Any route included in the movement route 9 that can connect the first specific section Z1 and the second specific section Z2 can be the connecting section.

[0026] As shown in Fig. 3, in this embodiment, the specific holding unit 3S includes a buffer for temporarily storing the item W. In the illustrated example, the buffer as the specific holding unit 3S is located between the first specific section Z1 and the second specific section Z2. This specific holding unit 3S is accessible by both the transport vehicle 1 located in the first specific section Z1 and the transport vehicle 1 located in the second specific section Z2. In other words, for either transport vehicle 1, the item W can be delivered to and from the specific holding unit 3S.

[0027] As shown in FIG. 1, the control system 2 is configured to cause the transport vehicles 1 to perform transport processing. In this example, a host control device that manages multiple transport vehicles 1 constitutes the control system 2. However, in a broad sense, the control system 2 is made up of various control devices within the article transport facility 100. For example, a transport vehicle control device (not shown) mounted on each transport vehicle 1 may constitute part or all of the control system 2.

[0028] The control system 2 includes, for example, a processor such as a microcomputer, peripheral circuits such as a memory, etc. Each process or function is realized by cooperation between this hardware and a program executed on the processor of a computer or the like.

[0029] The control system 2 specifies the origin F where the item W is held and the destination T of the item W for the transport vehicle 1 in the transport process. At this time, the control system 2 also specifies the route from the origin F to the destination T. The control system 2 can extract multiple routes, select the optimal route from among those routes (the route that minimizes the total time required from when a transport command is issued to when the transport process is completed) and specify it for the transport vehicle 1. In executing the transport process, the transport vehicle 1 moves to the origin F to receive the item W, and transports the received item W to the destination T and hands it over. The control system 2 is configured to perform a selection process when selecting a target transport vehicle 1, which is the transport vehicle 1 to perform the transport process, from multiple transport vehicles 1 that do not hold the item W.

[0030] Here, since there are multiple transport vehicles 1 on the movement route 9, each of the multiple transport vehicles 1 is a candidate for selection as the target transport vehicle 1. Then, the movement route 9 from each transport vehicle 1 to the origin F differs depending on the current position of each transport vehicle 1. In other words, there are multiple movement routes 9 from the transport vehicle 1 to the origin F.

[0031] However, if an item holding unit 3 other than the specific holding unit 3S is the origin F, the movement route 9 after the transport vehicle 1 receives the item W at the origin F, i.e., the movement route 9 from the origin F to the destination T, will be the same regardless of which transport vehicle 1 is selected as the target transport vehicle 1. As mentioned above, the movement route 9 is one-way, and it is easy to uniquely determine a rational movement route 9 from the item holding unit 3 (origin F) to the destination T.

[0032] On the other hand, when the specific holding unit 3S is the origin F, the movement route 9 from the origin F to the destination T also differs depending on which transport vehicle 1 is selected as the target transport vehicle 1. In other words, since the allowable movement direction of the transport vehicle 1 differs between the first specific section Z1 and the second specific section Z2, the subsequent movement route 9 to the destination T will be different when the transport vehicle 1 in the first specific section Z1 receives the item W from the specific holding unit 3S (origin F) and when the transport vehicle 1 in the second specific section Z2 receives the item W from the specific holding unit 3S (origin F).

[0033] Based on the above, a selection process is executed to select the target guided vehicle 1 that will perform the transportation process.

[0034] As shown in Figure 4, by executing the selection process, the control system 2 calculates the evaluation cost Cx of each transport vehicle 1 using cost C, which is a value for factors that affect the travel time of the transport vehicle 1 and increases as the travel time becomes longer, and selects the target transport vehicle 1 based on the evaluation cost Cx.

[0035] In the selection process when the specific holding unit 3S is the origin F, the evaluation cost Cx is calculated based on both the receiving cost Cr, which is the cost C corresponding to the travel time of the transport vehicle 1 from the current position P to the origin F, and the delivery cost Cg, which is the cost C corresponding to the travel time of the transport vehicle 1 from the origin F to the destination T. Note that the receiving cost Cr and the delivery cost Cg are each calculated by adding a variable cost, which is calculated taking into account the presence of other transport vehicles 1 on the route at the present time or in the future, to a base cost, which is calculated assuming that there are no other transport vehicles 1 on the route. Furthermore, when the route is defined by one or more links, these base cost and variable cost can also be calculated for each of the multiple links.

[0036] Fig. 4 is a diagram conceptually showing the receiving cost Cr and the delivery cost Cg. Fig. 4 also shows four transport vehicles A to D, each of which has a different current position P.

[0037] The receiving cost Cr and the delivery cost Cg are calculated as quantitative values ​​so that comparison between the transport vehicles A to D can be easily made.

[0038] Factors that affect the travel time of the transport vehicle 1 include, for example, the travel distance of the transport vehicle 1, the structure of the travel route 9, congestion on the travel route 9, the time required for the delivery of the item W, and the number of other transport vehicles 1 on the travel route 9. The cost C is set to increase as the travel time of the transport vehicle 1 increases due to such factors. In this embodiment, the calculation of the receiving cost Cr and the delivery cost Cg uses at least one of the following: a distance cost that increases as the travel distance of the transport vehicle 1 increases; a structure cost that increases as the maximum travel speed of the transport vehicle 1 decreases depending on the structure of the travel route 9 of the transport vehicle 1; a congestion cost that increases as the degree of congestion on the travel route 9 of the transport vehicle 1 increases; a transfer cost that increases as the time required for the transport vehicle 1 to deliver the item W between the item holder 3 and the destination T increases; and a other vehicle cost that increases as the number of other transport vehicles 1 on the travel route 9 of the transport vehicle 1 increases.

[0039] The distance cost is determined according to the length of the travel distance of the transport vehicle 1. In other words, the distance cost required from the current position P of the transport vehicle 1 to the origin F is determined according to the length of the travel path 9 from the current position P of the transport vehicle 1 to the origin F. Also, the distance cost required from the origin F to the destination T is determined according to the length of the travel path 9 from the origin F to the destination T. The longer the travel distance, the longer the travel time of the transport vehicle 1, and therefore the greater the distance cost becomes.

[0040] The structural cost is determined according to the structure of the movement path 9. For example, in a straight portion of the movement path 9, the maximum movement speed of the transport vehicle 1 is likely to be set high, and the movement time of the transport vehicle 1 is accordingly shorter, so the structural cost is relatively low. On the other hand, in a curved portion of the movement path 9 or in a junction where multiple movement paths 9 converge, the maximum movement speed of the transport vehicle 1 is likely to be set low, and the movement time of the transport vehicle 1 is accordingly longer, so the structural cost is relatively high.

[0041] The congestion cost is determined according to the degree of congestion (congestion level) that exists on the travel route 9. The higher the congestion level, the longer the travel time of the transported vehicle 1, and therefore the relatively higher the congestion cost. The congestion level is set, for example, according to the number of transported vehicles 1 in a predetermined section of the travel route 9, the passing speed or passing time of the transported vehicle 1, etc. The congestion level may also be set based on the length of the congestion. The length of the congestion may be the length of a congestion that actually exists on the travel route 9, or the length of a congestion that does not currently exist but is predicted to occur in the future.

[0042] The transfer cost is determined according to the time required for the transfer operation of the article W performed by the transport vehicle 1. As described above, in this embodiment, the transport vehicle 1 is equipped with a slide mechanism for sliding the gripping unit 10, a lifting mechanism for raising and lowering the gripping unit 10, and a turning mechanism for rotating the gripping unit 10. When the transfer operation of the article W is performed, the time required for the transfer operation will vary depending on whether the gripping unit 10 is slid or the amount of sliding if it is slid, whether it is raised or lowered or the amount of lifting if it is slid, and whether it is spun or the amount of rotation if it is spun. The longer the time required for the transfer operation, the longer the travel time of the transport vehicle 1, and therefore the relatively higher the transfer cost.

[0043] The other vehicle cost is determined according to the number of guided vehicles 1 other than the own vehicle that exist on the movement route 9. The presence of guided vehicles 1 other than the own vehicle imposes constraints on the movement of the own vehicle. The greater the number of guided vehicles 1 other than the own vehicle, the greater the constraints, which tends to increase the travel time of the own vehicle accordingly, resulting in a relatively higher other vehicle cost. Furthermore, the number of guided vehicles 1 other than the own vehicle may be the number of other guided vehicles 1 that actually exist, or may be the number of other guided vehicles 1 that may exist in the future.

[0044] The calculation of the receiving cost Cr and the delivery cost Cg uses at least one of the distance cost, structure cost, congestion cost, transfer cost, and other vehicle cost. These five costs are considered "element costs," and the receiving cost Cr and the delivery cost Cg are calculated, for example, by adding the element costs together, multiplying the element costs together, or by a combination of these. Then, in the selection process when the specific holding unit 3S is set as the transport source F, the control system 2 calculates the evaluation cost Cx based on both the calculated receiving cost Cr and delivery cost Cg.

[0045] In addition, in the selection process when an item holder 3 other than the specific holder 3S is set as the origin F, the evaluation cost Cx is calculated based on the receiving cost Cr, which is the cost C corresponding to the travel time from the current position P of the transport vehicle 1 to the origin F. In other words, the delivery cost Cg is not taken into consideration. The reason for this is that, as described above, the travel route 9 from the origin F to the destination T is the same regardless of which transport vehicle 1 is selected as the target transport vehicle 1.

[0046] FIG. 5 shows the evaluation cost Cx for each of the transportation vehicles A to D.

[0047] The control system 2 executes the selection process to calculate the evaluation cost Cx of each transport vehicle 1, and selects the transport vehicle 1 with the smallest evaluation cost Cx as the target transport vehicle 1. In this embodiment, the evaluation cost Cx is calculated by adding up the receiving cost Cr and the delivery cost Cg for each transport vehicle 1. The control system 2 compares the evaluation costs Cx calculated for each transport vehicle 1 to determine the smallest evaluation cost that results in the smallest evaluation cost Cx, and selects the transport vehicle 1 associated with the smallest evaluation cost as the target transport vehicle 1.

[0048] In the example shown in FIG. 5, the evaluation cost Cx for the guided vehicle B is the smallest, so the control system 2 selects the guided vehicle B as the target guided vehicle 1.

[0049] 6 illustrates an example in which the evaluation cost Cx is calculated using only the distance cost in the selection process when the specific holding unit 3S is the transportation source F. Referring to FIG. 6, the evaluation costs Cx for transportation vehicles A and B, which have different current positions P, are compared.

[0050] In the example shown in FIG. 6, the current position P of transport vehicle A is closer to the origin F than the current position P of transport vehicle B. Therefore, the receiving cost Cr of transport vehicle A is smaller than that of transport vehicle B. In the selection process, if only the movement route 9 from the current position P of transport vehicle 1 to the origin F is considered, transport vehicle A with the smaller receiving cost Cr is selected as the target transport vehicle 1.

[0051] However, since the specific holding unit 3S is set as the origin F, the travel route 9 from the first specific section Z1 to the destination T when the transport vehicle A receives the item W is different from the travel route 9 from the second specific section Z2 to the destination T when the transport vehicle B receives the item W. Therefore, the delivery costs Cg of each of the transport vehicles A and B must also be taken into consideration.

[0052] In the example shown in Figure 6, when transport vehicle B receives item W, the travel route 9 from the second specific section Z2 to the destination T is shorter than the travel route 9 from the first specific section Z1 to the destination T when transport vehicle A receives item W. Therefore, the delivery cost Cg of transport vehicle B is smaller than that of transport vehicle A.

[0053] In this embodiment, the evaluation cost Cx is calculated by adding up the receiving cost Cr and the delivery cost Cg for each transportation vehicle 1.

[0054] In the example shown in FIG. 6, the evaluation cost Cx (receiving cost Cr+delivery cost Cg) for transport vehicle B is smaller than the evaluation cost Cx (receiving cost Cr+delivery cost Cg) for transport vehicle A. Therefore, the control system 2 selects transport vehicle B as the target transport vehicle 1 in the selection process. This makes it possible to rationally transport the item W from the source F to the destination T using transport vehicle B.

[0055] Other Embodiments Next, other embodiments will be described.

[0056] (1) In the above embodiment, an example was described in which the first specific section Z1 and the second specific section Z2 were arranged side by side. However, without being limited to this example, the first specific section Z1 and the second specific section Z2 may be arranged side by side in a manner other than being continuously arranged along the extension direction of the travel path 9. Therefore, for example, as shown in FIG. 7, in a portion where the travel path 9 has multiple sections arranged along the vertical direction, the first specific section Z1 and the second specific section Z2 may be arranged side by side vertically. In this case, both the transport vehicle 1 in the first specific section Z1 and the transport vehicle 1 in the second specific section Z2 can transfer an article W between them and the article holder 3 arranged below both the first specific section Z1 and the second specific section Z2. Therefore, such an article holder 3 is also considered a specific holder 3S.

[0057] (2) In the above embodiment, an example has been described in which the movement direction of the transport vehicle 1 permitted in the first specific section Z1 and the movement direction of the transport vehicle 1 permitted in the second specific section Z2 are set to be different from each other. However, without being limited to this example, these movement directions may be set to be the same.

[0058] (3) In the above embodiment, an example has been described in which the evaluation cost Cx is calculated by adding up the receiving cost Cr and the delivery cost Cg for each transport vehicle 1. However, without being limited to such an example, the evaluation cost Cx may be calculated, for example, by multiplying the receiving cost Cr and the delivery cost Cg.

[0059] (4) In the above embodiment, an example has been described in which the evaluation cost Cx of the transport vehicle 1 is calculated based on three locations: the current location P of the transport vehicle 1, the origin F, and the destination T. However, in addition to this, for example, the evaluation cost Cx may also be calculated based on a fourth location that the transport vehicle 1 can reach. An example of the fourth location is a maintenance station where the transport vehicle 1 performs maintenance and inspections. When the transport vehicle 1 needs repair or charging, the transport vehicle 1 heads to the maintenance station (fourth location) after completing the transport process. The calculation of the evaluation cost Cx also takes into account the cost required for the transport vehicle 1 to travel to the maintenance station.

[0060] (5) In the above embodiment, an example has been described in which the travel path 9 is configured using rails 90 installed near the ceiling. However, without being limited to such an example, the travel path 9 may be configured using rails installed near the floor, and the transport vehicle 1 may be configured to move along the rails. Alternatively, the travel path 9 may be configured using magnetic tape installed on the floor, and the transport vehicle 1 may be configured to move along the magnetic tape.

[0061] (6) The configurations disclosed in the above-described embodiments may be combined with configurations disclosed in other embodiments as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications may be made as appropriate within the scope of the present disclosure.

[0062] [Summary of this embodiment] The summary of this embodiment will be described below.

[0063] An article transport facility comprising: a plurality of transport vehicles that move along a predetermined travel path to transport articles; and a control system that causes the transport vehicles to perform a transport process in which a source and a destination of the article are specified, an article holding unit capable of holding the article and allowing the transport vehicle to hand over the article is disposed at a plurality of locations along the movement path; at least one of the plurality of article holding units is a specific holding unit that can receive and deliver the article from the transport vehicle located in any of a plurality of specific sections on the movement route; the control system is configured to execute a selection process in which, when selecting a target transport vehicle that is a transport vehicle to perform the transport process from among a plurality of transport vehicles that are not holding the item, the control system calculates an evaluation cost of each transport vehicle using a cost that is a value for a factor that affects a travel time of the transport vehicle and that increases as the travel time becomes longer, and selects the transport vehicle with the smallest evaluation cost as the target transport vehicle; In the selection process when the specified holding unit is the source of transport, the evaluation cost is calculated based on both the receiving cost, which is the cost corresponding to the travel time of the transport vehicle from the current location to the source of transport, and the delivery cost, which is the cost corresponding to the travel time of the transport vehicle from the source of transport to the destination.

[0064] According to this configuration, when the specific holding unit is set as the origin of a transport vehicle, a target transport vehicle to perform the transport process can be selected based on both the cost corresponding to the travel time from the current location of the transport vehicle to the origin and the cost corresponding to the travel time from the origin to the destination of the transport vehicle. In other words, the situation after the transport vehicle receives the item at the origin can also be used as a criterion for selecting the target transport vehicle. Therefore, according to this configuration, it is possible to realize highly rational transport of items.

[0065] In the selection process when an item holding unit other than the specified holding unit is set as the source of transport, it is preferable that the evaluation cost is calculated based on the receiving cost, which is the cost corresponding to the travel time from the current position of the transport vehicle to the source of transport.

[0066] For example, if the movement direction of a transport vehicle on a travel route is limited to one direction and an item holding unit other than a specific holding unit is used as the origin, the travel route to the destination (the travel route from the origin to the destination) after the transport vehicle receives the item at the origin will be the same regardless of which transport vehicle is used. In such cases, there is little need to consider delivery costs when calculating the evaluation cost. According to this configuration, in the selection process when an item holding unit other than a specific holding unit is used as the origin, the evaluation cost is calculated based on the receiving cost, so delivery costs can be excluded from the calculation elements, and the computational load on the control system can be reduced.

[0067] the plurality of specific sections include a first specific section and a second specific section arranged in parallel with each other; a movement direction of the transporting vehicle permitted in the first specific section and a movement direction of the transporting vehicle permitted in the second specific section are set to be different from each other; Preferably, the first specific section and the second specific section are connected via a connecting section so that the transport vehicle can move.

[0068] Depending on whether the transport vehicle passes through the first specific section or the second specific section, the travel route until reaching the specific holding unit will differ, and the travel route from the specific holding unit to the destination will also likely differ. However, as described above, the evaluation cost, which serves as an index for selecting a target transport vehicle, is calculated based on both the receiving cost corresponding to the travel route until the transport vehicle reaches the specific holding unit and the delivery cost corresponding to the travel route from the specific holding unit to the destination. Therefore, even when the travel route includes the first specific section and the second specific section as in this configuration, the control system can select the optimal transport vehicle as the target transport vehicle.

[0069] The calculation of the receiving cost and the delivery cost includes: a distance cost that increases as the travel distance of the transport vehicle increases; a structural cost that increases as the movable speed of the transport vehicle decreases depending on the structure of the transport vehicle's movement route; a congestion cost that increases as the degree of congestion on the travel route of the transport vehicle increases; a transfer cost that increases as the time taken for the transport vehicle to transfer the article between the article holding unit and the transport destination increases; and Other vehicle costs increase as the number of other transport vehicles present on the travel route of the transport vehicle increases; It is preferable that at least one of the following is used.

[0070] This configuration allows various costs to be appropriately determined based on various factors that affect the travel time of the transport vehicle. These costs are used in calculating the receiving cost and the delivery cost, and in turn, the evaluation cost, making it possible to appropriately select the target transport vehicle. [Industrial Applicability]

[0071] The technology disclosed herein can be used in an item transport facility that includes a plurality of transport vehicles that move along a predetermined travel path to transport items, and a control system that causes the transport vehicles to perform a transport process in which the source and destination of the items are specified. [Explanation of symbols]

[0072] 100: Goods transport equipment 1: Transport vehicle 2: Control system 3: Article holding part 3S: Specific holding part 9: Travel route Cx: Evaluation cost C: Cost Cg: Delivery cost Cr: Receipt cost F: Origin T: Destination P:Current position Z: Specific section Z1: First specific section Z2: Second specific section W:Goods

Claims

1. An article transport facility comprising: a plurality of transport vehicles that move along a predetermined travel path to transport articles; and a control system that causes the transport vehicles to perform a transport process in which a source and a destination of the article are specified, an article holding unit capable of holding the article and allowing the transport vehicle to hand over the article is disposed at a plurality of locations along the movement path; at least one of the plurality of article holding units is a specific holding unit that can receive and deliver the article from the transport vehicle located in any of a plurality of specific sections on the movement route, the control system is configured to execute a selection process in which, when selecting a target transport vehicle that is a transport vehicle to perform the transport process from among a plurality of transport vehicles that are not holding the item, the control system calculates an evaluation cost of each transport vehicle using a cost that is a value for a factor that affects a travel time of the transport vehicle and that increases as the travel time becomes longer, and selects the transport vehicle with the smallest evaluation cost as the target transport vehicle; In the selection process when the specific holding unit is the source of transport, the evaluation cost is calculated based on both the receiving cost, which is the cost corresponding to the travel time of the transport vehicle from the current location to the source of transport, and the delivery cost, which is the cost corresponding to the travel time of the transport vehicle from the source of transport to the destination of transport.

2. 2. The item transport equipment of claim 1, wherein in the selection process when an item holding unit other than the specific holding unit is set as the source of transport, the evaluation cost is calculated based on the receiving cost, which is the cost corresponding to the travel time from the current position of the transport vehicle to the source of transport.

3. the plurality of specific sections include a first specific section and a second specific section arranged in parallel with each other, a movement direction of the transporting vehicle permitted in the first specific section and a movement direction of the transporting vehicle permitted in the second specific section are set to be different from each other; The article transport facility according to claim 1 or 2, wherein the first specific section and the second specific section are connected via a connecting section so that the transport vehicle can move.

4. The calculation of the receiving cost and the delivery cost includes: a distance cost that increases as the travel distance of the transport vehicle increases; a structural cost that increases as the movable speed of the transport vehicle decreases depending on the structure of the transport vehicle's movement route; a congestion cost that increases as the degree of congestion on the travel route of the transport vehicle increases; a transfer cost that increases as the time taken for the transport vehicle to transfer the article between the article holding unit and the transport destination increases; and Other vehicle costs increase as the number of other transport vehicles present on the travel route of the transport vehicle increases; The article transport facility according to claim 1 or 2, wherein at least one of the following is used.

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