Article conveying facility

Abstract

An article transport facility is provided with a plurality of transport vehicles (1) and a control system. In a case where a target transport vehicle (1) to be subjected to transport processing is selected from a plurality of transport vehicles (1) that do not hold an article, a control system executes a selection process for calculating an evaluation cost (Cx) for each of the transport vehicles (1) using a cost, which is a value related to a main cause of an influence on a movement time of the transport vehicle (1) and which increases as the movement time increases; the transport vehicle (1) with the minimum evaluation cost (Cx) is selected as the target transport vehicle (1). In the selection process when the specific holding unit is the transport start point (F), the evaluation cost (Cx) is calculated on the basis of both a reception cost (Cr) corresponding to the time of movement of the transport vehicle (1) from the current position (P) to the transport start point (F) and a transfer cost (Cg) corresponding to the time of movement of the transport vehicle (1) from the transport start point (F) to the transport destination (T).

Description

Technical Field

[0001] The present invention relates to an article conveying device comprising: a plurality of conveying vehicles that convey articles by moving along a predetermined movement path; and a control system that causes the conveying vehicles to perform a conveying process that specifies a conveying start point and a conveying destination of the articles. Background Art

[0002] For example, Japanese Patent Application Publication No. 2020-66499 (Patent Document 1) discloses a conveying system used in a factory that manufactures semiconductor products. In such a conveying system, in order to perform various treatments on the articles, the articles are transported between processes by a conveying vehicle. Generally speaking, based on a conveying instruction issued by a system controller of a management system, a conveying vehicle receives the article at a conveying starting point where the specified article is present and transports the article to a specified conveying destination. Summary of the Invention

[0003] However, when selecting a transport vehicle from among multiple transport vehicles to transport an item, in order to efficiently transport the item, the transport vehicle that is closest to the location (transportation starting point) where the item is to be stored is often selected, taking into account factors such as transport time. However, in situations where the route is complex or there are restrictions on the transport vehicle's movement along the route, there may be multiple transport vehicle paths from the transport starting point to the destination after receiving the item. Therefore, when the distance between the transport starting point and the transport vehicle is used as the sole criterion for selecting the transport vehicle to transport an item, it is sometimes impossible to achieve efficient item transportation.

[0004] In view of the above-mentioned actual situation, an article transport facility capable of realizing highly rational article transport is desired.

[0005] The technology for solving the above-mentioned problems is as follows. An article conveying device is provided, comprising: a plurality of conveying vehicles that move along a predetermined movement path to convey articles; and a control system that causes the conveying vehicles to perform conveying processing that specifies a conveying start point and a conveying destination of the articles. Article holding portions capable of holding the articles and allowing the transport vehicle to deliver the articles are disposed at multiple locations along the moving path. At least one of the plurality of article holding sections is a specific holding section from which the article can be delivered from any of the transport vehicles located in a plurality of specific sections of the movement path. The control system is configured as follows: when selecting a target transport vehicle as the transport vehicle to be used for the transport process from among a plurality of transport vehicles that do not hold the article, the control system performs the following selection process: using a value that is a major factor affecting the travel time of the transport vehicle and a cost that increases as the travel time increases, an evaluation cost of each transport vehicle is calculated, and the transport vehicle with the smallest evaluation cost is selected as the target transport vehicle; In the selection process in which the specific holding portion is the transport starting point, the evaluation cost is calculated based on both the receiving cost, which is the cost corresponding to the moving time of the transport vehicle from the current position to the transport starting point, and the handover cost, which is the cost corresponding to the moving time of the transport vehicle from the transport starting point to the transport destination.

[0006] According to this configuration, when a specific holding portion is the transport vehicle's transport starting point, the transport vehicle to be transported can be selected based on both the cost associated with the transport vehicle's travel time from its current location to the transport starting point and the cost associated with the transport vehicle's travel time from the transport starting point to the transport destination. In other words, the condition of the transport vehicle after receiving the item at the transport starting point can also be used as a basis for selecting the target transport vehicle. Therefore, this configuration enables highly efficient transport of items.

[0007] 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 with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a top view of the article conveying equipment. Figure 2 It is a front view showing the article holding portion. Figure 3 It is a front view showing the specific holding portion. Figure 4 This is an explanatory diagram conceptually showing reception cost and handover cost. Figure 5 It is an explanatory diagram showing the evaluation cost calculated for each transport vehicle. Figure 6 1 is a diagram showing a comparative example of evaluation costs of the transport vehicle A and the transport vehicle B. FIG. Figure 7 is a diagram showing another example of a specific section. DETAILED DESCRIPTION

[0009] Hereinafter, embodiments of the article transport facility will be described with reference to the accompanying drawings.

[0010] like Figure 1As shown, the article transport facility 100 comprises: a plurality of transport vehicles 1, which move along a predetermined movement path 9 to transport articles W (see Figure 2 、 3 and a control system 2, which enables the transport vehicle 1 to carry out the transport processing of the transport starting point F and the transport destination T of the specified article W.

[0011] In this embodiment, the moving direction of the transport vehicle 1 is set to a constant direction on the moving path 9. In other words, the moving path 9 is a one-way path, and the transport vehicle 1 cannot move backward.

[0012] like Figure 2 and Figure 3 As shown, in this embodiment, the moving path 9 is set at a position away from the ground. For example, the moving path 9 is formed using a track 90 provided near the ceiling. The transport vehicle 1 is configured as a so-called ceiling transport vehicle and travels on the track 90 along the moving path 9.

[0013] There are various articles W that are handled by the article transport equipment 100. In this embodiment, the article transport equipment 100 is used in a semiconductor manufacturing facility. Therefore, articles W include substrate containers (so-called FOUPs) that hold substrates (wafers, panels, etc.) or reticle containers (so-called reticle cassettes) that hold reticles. In this case, the transport vehicle 1 transports articles W, such as substrate containers or reticle containers, along the travel path 9 between various processes.

[0014] like Figure 1 As shown, article holding units 3 are arranged at multiple locations along the travel path 9 . The article holding units 3 can hold articles W and can receive and deliver the articles W from the transport vehicle 1 .

[0015] like Figure 2 As shown, in this embodiment, the article holding unit 3 includes a load port disposed adjacent to a processing device 30 that processes the article W. "Processing the article W" refers to processing of a contained object (substrate or reticle) contained in a container serving as the article W. The processing device 30 performs various processes, such as thin film formation, photolithography, and etching.

[0016] The transport vehicle 1 receives an article W that has been processed by the processing device 30 from the article holding portion 3 or transfers an article W that has not been processed by the processing device 30 to the article holding portion 3. The transport vehicle 1 includes a gripping portion 10 configured to grip the article W, and is configured to transfer the article W to and from the article holding portion 3 via the gripping portion 10.

[0017] In the illustrated example, the loading port serving as the article holder 3 is located below the travel path 9 of the transport vehicle 1. The transport vehicle 1 transfers articles W to and from the article holder 3 by raising and lowering the gripping portion 10.

[0018] In addition, if Figure 2 As shown, when the article holding portion 3 is not positioned directly below the moving path 9 but is laterally offset from the moving path 9, the transport vehicle 1 slides the gripping portion 10 laterally from the vehicle body to position the gripping portion 10 directly above the article holding portion 3. Thereafter, the transport vehicle 1 raises and lowers the gripping portion 10 to transfer the article W to and from the article holding portion 3.

[0019] Furthermore, the structure of the article holding portion 3 may restrict the orientation of the article W placed therein. In such cases, the transport vehicle 1 rotates the gripping portion 10 about its vertical axis to change the orientation of the article W gripped by the gripping portion 10. This allows the article W to be oriented appropriately relative to the article holding portion 3.

[0020] Thus, in this embodiment, the transport vehicle 1 includes a sliding mechanism for sliding the gripping portion 10, a lifting mechanism for raising and lowering the gripping portion 10, and a rotating mechanism for rotating the gripping portion 10. When transferring an article W, the time required for the transfer operation varies depending on whether the gripping portion 10 is slid, raised, or rotated. Furthermore, the transfer operation described above can also be referred to as a "transfer operation."

[0021] like Figure 1 As shown, at least one of the plurality of article holding units 3 is a specific holding unit 3S from which articles W can be delivered from any of the transport vehicles 1 located in the plurality of specific zones Z of the travel path 9 .

[0022] The plurality of specific sections Z include a first specific section Z1 and a second specific section Z2 arranged side by side. "Arranged side by side" means that the first specific section Z1 and the second specific section Z2 are arranged side by side in a configuration other than a configuration that is continuous and parallel along the direction of extension of the movement path 9. Therefore, the first specific section Z1 and the second specific section Z2 do not need to be arranged side by side in parallel. In this example, the first specific section Z1 and the second specific section Z2 are arranged side by side in a horizontal manner.

[0023] In this embodiment, the movement direction of the transport vehicle 1 permitted in the first specific zone Z1 and the movement direction of the transport vehicle 1 permitted in the second specific zone Z2 are set to be different from each other. Figure 1In the example shown, the transport vehicle 1 is allowed to move only downward in the first specific zone Z1 and only upward in the second specific zone Z2.

[0024] Thus, the first specific section Z1 and the second specific section Z2 are arranged side by side and allow different directions of movement of the transport vehicle 1. However, when viewed as the entire movement path 9, the first specific section Z1 and the second specific section Z2 are connected via the connecting section so that the transport vehicle 1 can move. As paths included in the movement path 9, all paths that can connect the first specific section Z1 and the second specific section Z2 can be considered connecting sections.

[0025] like Figure 3 As shown, in this embodiment, the specific holding section 3S includes a buffer for temporarily placing articles W. In the illustrated example, the buffer serving as the specific holding section 3S is located between the first specific zone Z1 and the second specific zone Z2. Both transport vehicles 1 in the first specific zone Z1 and in the second specific zone Z2 can access the specific holding section 3S. In other words, either transport vehicle 1 can transfer articles W to and from the specific holding section 3S.

[0026] like Figure 1 As shown, the control system 2 is configured so that the transport vehicles 1 perform transport processing. In this example, the control system 2 is composed of a superior control device that centrally manages multiple transport vehicles 1. However, the control system 2 is generally composed of various control devices within the article transport system 100. For example, a transport vehicle control device (not shown) mounted on each transport vehicle 1 may also constitute part or all of the control system 2.

[0027] The control system 2 includes, for example, a processor such as a microcomputer, peripheral circuits such as a memory, etc. Each process or each function is realized by cooperation between these hardware and a program executed on the processor such as a computer.

[0028] In the transport process performed by the transport vehicle 1 by the control system 2, the transport starting point F for holding the article W and the transport destination T of the article W are specified. In addition, at this time, the control system 2 specifies the path from the transport starting point F to the transport destination T. The control system 2 is capable of extracting multiple paths, selecting the best path (the path with the shortest total time required from issuing a transport instruction to completing the transport process) from these paths, and assigning it to the transport vehicle 1. During the execution of the transport process, the transport vehicle 1 moves to the transport starting point F and receives the article W, transports the received article W to the transport destination T, and hands it over. The control system 2 is configured as follows: in the case of selecting the target transport vehicle 1 as the transport vehicle 1 to be transported from a plurality of transport vehicles 1 that do not hold the article W, a selection process is performed.

[0029] Here, there are multiple transport vehicles 1 on the travel path 9, and thus each of the multiple transport vehicles 1 is a candidate for selection as the target transport vehicle 1. Furthermore, the travel path 9 from each transport vehicle 1 to the transport starting point F is different depending on the current position of each transport vehicle 1. In other words, there are multiple travel paths 9 from the transport vehicle 1 to the transport starting point F.

[0030] However, when an article holding unit 3 other than the specific holding unit 3S is the transport starting point F, the movement path 9 of the transport vehicle 1 after receiving the article W at the transport starting point F (i.e., the movement path 9 from the transport starting point F to the transport destination T) is the same regardless of which transport vehicle 1 is selected as the target transport vehicle 1. This is because, as described above, the movement path 9 is unidirectional, and a reasonable movement path 9 from the article holding unit 3 (the transport starting point F) to the transport destination T is easily and uniquely determined.

[0031] On the other hand, when the specific holding portion 3S is the transport starting point F, the movement path 9 from the transport starting point F to the transport destination T also differs depending on which transport vehicle 1 is selected as the target transport vehicle 1. That is, the permitted movement directions of the transport vehicle 1 differ between the first specific zone Z1 and the second specific zone Z2. Therefore, when a transport vehicle 1 in the first specific zone Z1 receives an article W from the specific holding portion 3S (the transport starting point F), the subsequent movement path 9 to the transport destination T will differ from that when a transport vehicle 1 in the second specific zone Z2 receives an article W from the specific holding portion 3S (the transport starting point F).

[0032] Based on the above, the selection process for selecting the target transport vehicle 1 to be subjected to the transport process is executed.

[0033] like Figure 4As shown, the control system 2 calculates the evaluation cost Cx of each transport vehicle 1 using the cost C by executing the selection process, and selects the target transport vehicle 1 based on the evaluation cost Cx, where the cost C is a value related to the main factors affecting the travel time of the transport vehicle 1 and increases as the travel time increases.

[0034] In the selection process when the specific holding unit 3S is the transport starting point F, the evaluation cost Cx is calculated based on both the receiving cost Cr, which is the cost C corresponding to the time it takes for the transport vehicle 1 to travel from the current position P to the transport starting point F, and the handover cost Cg, which is the cost C corresponding to the time it takes for the transport vehicle 1 to travel from the transport starting point F to the transport destination T. Furthermore, the receiving cost Cr and the handover cost Cg are each calculated by adding a variable cost calculated to account for the current or future presence of other transport vehicles 1 on the route to a base cost calculated assuming no other transport vehicles 1 are on the route. Furthermore, when the route is defined by a single link or multiple links, these base and variable costs can be calculated for each of the multiple links.

[0035] Figure 4 is a diagram conceptually showing the reception cost Cr and the handover cost Cg. Figure 4 In FIG, four transport vehicles A to D are illustrated, and the current position P of each transport vehicle 1 is different.

[0036] The receiving cost Cr and the handover cost Cg are calculated as quantitative values ​​in order to facilitate comparison among the transport vehicles A to D.

[0037] Factors that affect the travel time of the transport vehicle 1 include, for example, the distance the transport vehicle 1 travels, the structure of the transport path 9, congestion in the transport path 9, the time required to transfer the article W, and the number of other transport vehicles 1 on the transport path 9. Cost C is set so that the longer the travel time of the transport vehicle 1 is due to these factors, the greater the cost. In this embodiment, the calculation of the receiving cost Cr and the handover cost Cg uses at least one of the following: distance cost, which increases as the travel distance of the transport vehicle 1 increases; structural cost, which increases as the transport vehicle 1's travel speed decreases in accordance with the structure of the transport vehicle 1's transport path 9; congestion cost, which increases as the degree of congestion in the transport vehicle 1's transport path 9 increases; transfer cost, which increases as the time required to transfer the article W between the transport vehicle 1 and the article holder 3 and the destination T increases; and other vehicle cost, which increases as the number of other transport vehicles 1 on the transport vehicle 1's transport path 9 increases.

[0038] The distance cost is determined according to the length of the transport vehicle 1's travel distance. In other words, the distance cost it takes for the transport vehicle 1 to travel from its current position P to the transport starting point F is determined according to the length of the travel path 9 from the transport starting point F to the transport destination T. Furthermore, the distance cost from the transport starting point F to the transport destination T is determined according to the length of the travel path 9 from the transport starting point F to the transport destination T. The longer the travel distance, the longer the transport vehicle 1 travels, and thus the distance cost becomes relatively greater.

[0039] The construction cost is determined according to the structure of the travel path 9. For example, in a straight portion of the travel path 9, the movable speed of the transport vehicle 1 is easily set to a high speed, and accordingly, the travel time of the transport vehicle 1 is shortened, thereby reducing the construction cost. On the other hand, in a curved portion of the travel path 9 or a confluence portion where multiple travel paths 9 converge, the movable speed of the transport vehicle 1 is easily set to a low speed, and accordingly, the travel time of the transport vehicle 1 is prolonged, thereby increasing the construction cost.

[0040] The congestion cost is determined in accordance with the degree of congestion (congestion degree) existing in the moving path 9. The higher the congestion degree, the longer the travel time of the transport vehicle 1 is, and thus the congestion cost becomes relatively large. The congestion degree is set in accordance with, for example, the number of transport vehicles 1 at a predetermined section of the moving path 9, the speed of travel of the transport vehicles 1, or the travel time. In addition, the congestion degree can also be set based on the length of the congestion. The length of the congestion can be the length of the congestion actually existing in the moving path 9, or the length of the congestion that does not currently exist but is predicted to occur in the future.

[0041] The transfer cost is determined in accordance with the time taken for the transfer operation of the article W performed by the transport vehicle 1. As described above, in the present embodiment, the transport vehicle 1 includes a sliding mechanism for sliding the gripping portion 10, a lifting mechanism for raising and lowering the gripping portion 10, and a rotating mechanism for rotating the gripping portion 10. When performing the transfer operation of the article W, the time taken for the transfer operation varies depending on whether the gripping portion 10 is slid or the amount of sliding when the gripping portion 10 is slid, whether the gripping portion 10 is raised or lowered or the amount of lifting when the gripping portion 10 is raised or lowered, and whether the gripping portion 10 is rotated or the amount of rotation when the gripping portion 10 is rotated. The longer the time taken for the transfer operation, the longer the moving time of the transport vehicle 1, and thus the transfer cost becomes relatively large.

[0042] The other vehicle cost is determined in accordance with the number of transport vehicles 1 other than the vehicle on the travel path 9. The presence of transport vehicles 1 other than the vehicle imposes constraints on the movement of the vehicle. The greater the number of transport vehicles 1 other than the vehicle, the greater the constraints. Consequently, the travel time of the vehicle tends to be longer, and the other vehicle cost is relatively increased. Furthermore, the number of transport vehicles 1 other than the vehicle can be either the actual number of transport vehicles 1 or the number of transport vehicles 1 that may exist in the future.

[0043] The calculation of the receiving cost Cr and the handover cost Cg uses at least one of these distance costs, construction costs, congestion costs, transfer costs, and other vehicle costs. These five costs are referred to as "elementary costs," and the receiving cost Cr and the handover cost Cg are calculated, for example, by adding the elemental costs, multiplying them, or a combination thereof. Furthermore, when selecting the specific holding unit 3S as the transport starting point F, the control system 2 calculates an evaluation cost Cx based on both the calculated receiving cost Cr and the handover cost Cg.

[0044] Furthermore, in the selection process when an article holder 3 other than the specific holder 3S is the transport starting point F, the evaluation cost Cx is calculated based on 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 transport starting point F. In other words, the handover cost Cg is not taken into account. The reason for this is that, as described above, the travel path 9 from the transport starting point F to the transport destination T is the same regardless of which transport vehicle 1 is selected as the target transport vehicle 1.

[0045] Figure 5 The evaluation cost Cx for each of the transport vehicles A to D is shown.

[0046] The control system 2 performs a selection process to calculate an evaluation cost Cx for each transport vehicle 1 and selects the transport vehicle 1 with the lowest evaluation cost Cx as the target transport vehicle 1. In this embodiment, the evaluation cost Cx is calculated by summing the reception cost Cr and the transfer cost Cg for each transport vehicle 1. The control system 2 compares the evaluation costs Cx calculated for each transport vehicle 1, calculates the minimum evaluation cost with the lowest evaluation cost Cx, and selects the transport vehicle 1 with the lowest evaluation cost as the target transport vehicle 1.

[0047] exist Figure 5 In the example shown, the evaluation cost Cx for the transport vehicle B becomes the smallest minimum evaluation cost, and thus the control system 2 selects the transport vehicle B as the target transport vehicle 1 .

[0048] Figure 6The example in which the evaluation cost Cx is calculated using only the distance cost in the selection process when the specific holding portion 3S is the conveyance starting point F is shown. Figure 6 The evaluation costs Cx of the transport vehicle A and the transport vehicle B, which have different current positions P, are compared.

[0049] exist Figure 6 In the example shown, the current position P of transport vehicle A is closer to the transport starting point F than the current position P of transport vehicle B. Therefore, the reception cost Cr for transport vehicle A is lower than that for transport vehicle B. In the selection process, if only the movement path 9 of transport vehicle 1 from the current position P to the transport starting point F is considered, transport vehicle A, which has the lower reception cost Cr, is selected as the target transport vehicle 1.

[0050] However, because the specific holding portion 3S is the transport starting point F, the movement path 9 from the first specific section Z1 to the transport destination T when transport vehicle A receives the article W is different from the movement path 9 from the second specific section Z2 to the transport destination T when transport vehicle B receives the article W. Therefore, the transfer costs Cg of each transport vehicle A and transport vehicle B must also be considered.

[0051] exist Figure 6 In the example shown, the movement path 9 from the second specific section Z2 to the transport destination T when transport vehicle B receives the article W is shorter than the movement path 9 from the first specific section Z1 to the transport destination T when transport vehicle A receives the article W. Therefore, the transfer cost Cg for transport vehicle B is lower than that for transport vehicle A.

[0052] In the present embodiment, the evaluation cost Cx is calculated by totaling the reception cost Cr and the handover cost Cg for each transport vehicle 1 .

[0053] exist Figure 6 In the example shown, the evaluation cost Cx (receiving cost Cr + handover cost Cg) for transport vehicle B is lower than the evaluation cost Cx (receiving cost Cr + handover cost Cg) for transport vehicle A. Therefore, during the selection process, control system 2 selects transport vehicle B as the target transport vehicle 1. This allows transport vehicle B to be used to efficiently transport article W from the transport origin F to the transport destination T.

[0054] [Other implementation methods] Next, other embodiments will be described.

[0055] (1) In the above embodiment, an example in which the first specific section Z1 and the second specific section Z2 are arranged side by side is described. However, the present invention is not limited to such an example, and the first specific section Z1 and the second specific section Z2 may be arranged side by side in a form other than a form in which they are arranged side by side continuously along the extension direction of the moving path 9. Therefore, for example, Figure 7 As shown, it is also possible to arrange the first specific zone Z1 and the second specific zone Z2 side by side vertically in a portion of the travel path 9 where there are multiple sections along the vertical direction. In this case, either the transport vehicle 1 in the first specific zone Z1 or the transport vehicle 1 in the second specific zone Z2 can transfer articles W to and from the article holding sections 3 arranged below both the first specific zone Z1 and the second specific zone Z2. Therefore, such article holding sections 3 are also designated as specific holding sections 3S.

[0056] (2) In the above embodiment, an example is described in which the movement direction of the transport vehicle 1 permitted in the first specific zone Z1 and the movement direction of the transport vehicle 1 permitted in the second specific zone Z2 are set to be different from each other. However, the present invention is not limited to such an example, and these movement directions may also be set to be the same direction.

[0057] (3) In the above embodiment, an example is described in which the evaluation cost Cx is calculated by summing the reception cost Cr and the handover cost Cg for each transport vehicle 1. However, the present invention is not limited to this example, and the evaluation cost Cx may be calculated by, for example, multiplying the reception cost Cr by the handover cost Cg.

[0058] (4) In the above-mentioned embodiment, an example of calculating the evaluation cost Cx for the transport vehicle 1 based on three locations, namely, the current position P of the transport vehicle 1, the transport starting point F, and the transport destination T, is described. However, in addition to this, the evaluation cost Cx may also be calculated based on, for example, a fourth location that the transport vehicle 1 can reach. As an example of the fourth location, a maintenance station for the transport vehicle 1 to undergo maintenance and inspection can be listed. When the transport vehicle 1 needs to be repaired or charged, the transport vehicle 1 goes to the maintenance station (the fourth location) after completing the transport process. In the calculation of the evaluation cost Cx, the cost of the transport vehicle 1 going to the maintenance station is also taken into account.

[0059] (5) In the above embodiment, an example is described in which the moving path 9 is formed using a track 90 provided near the ceiling. However, the present invention is not limited to this example. Alternatively, the moving path 9 may be formed using a track provided near the ground, and the transport vehicle 1 may be configured to move along the track. Alternatively, the moving path 9 may be formed using a magnetic tape provided on the ground, and the transport vehicle 1 may be configured to move along the magnetic tape.

[0060] (6) In addition, the configurations disclosed in the above-mentioned embodiments can also be combined and applied with the configurations disclosed in other embodiments, as long as no contradiction arises. With respect to other configurations, the embodiments disclosed in this specification are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the scope of the present disclosure.

[0061] Summary of this embodiment Hereinafter, a summary of this embodiment will be described.

[0062] An article conveying device is provided, comprising: a plurality of conveying vehicles that move along a predetermined movement path to convey articles; and a control system that causes the conveying vehicles to perform conveying processing that specifies a conveying start point and a conveying destination of the articles. Article holding portions capable of holding the articles and allowing the transport vehicle to deliver the articles are disposed at multiple locations along the moving path. At least one of the plurality of article holding sections is a specific holding section from which the article can be delivered from any of the transport vehicles located in a plurality of specific sections of the movement path. The control system is configured as follows: when selecting a target transport vehicle as the transport vehicle to be used for the transport process from among a plurality of transport vehicles that do not hold the article, the control system performs the following selection process: using a value that is a major factor affecting the travel time of the transport vehicle and a cost that increases as the travel time increases, an evaluation cost of each transport vehicle is calculated, and the transport vehicle with the smallest evaluation cost is selected as the target transport vehicle; In the selection process in which the specific holding portion is the transport starting point, the evaluation cost is calculated based on both the receiving cost, which is the cost corresponding to the moving time of the transport vehicle from the current position to the transport starting point, and the handover cost, which is the cost corresponding to the moving time of the transport vehicle from the transport starting point to the transport destination.

[0063] According to this configuration, when a specific holding portion is the transport vehicle's transport starting point, the transport vehicle to be transported can be selected based on both the cost associated with the transport vehicle's travel time from its current location to the transport starting point and the cost associated with the transport vehicle's travel time from the transport starting point to the transport destination. In other words, the condition of the transport vehicle after receiving the item at the transport starting point can also be used as a basis for selecting the target transport vehicle. Therefore, this configuration enables highly efficient transport of items.

[0064] Preferably, in the selection process when the article holding portion other than the specific holding portion is the transport starting point, the evaluation cost is calculated based on the reception cost which is the cost corresponding to the travel time of the transport vehicle from the current position to the transport starting point.

[0065] For example, in a case where the direction of movement of a transport vehicle in its moving path is restricted to one direction, and an article holding portion other than a specific holding portion is the starting point of transport, the moving path from the transport vehicle receiving the article at the transport starting point to the transport destination (the moving path from the transport starting point to the transport destination) is the same regardless of which transport vehicle is the target. In such a case, the necessity of considering the transfer cost in calculating the evaluation cost is low. According to this configuration, in the selection process in which an article holding portion other than a specific holding portion is the starting point of transport, the evaluation cost is calculated based on the receiving cost, so that the transfer cost can be excluded from the calculation factors, which can reduce the computational load of the control system.

[0066] Preferably, the plurality of specific intervals include a first specific interval and a second specific interval arranged in parallel with each other, The movement direction of the transport vehicle permitted in the first specific section and the movement direction of the transport vehicle permitted in the second specific section are set to be different from each other. The first specific section and the second specific section are connected via a connecting section so that the transport vehicle can move therebetween.

[0067] Depending on whether the transport vehicle passes through the first or second specific section, the path it takes until it reaches the specific holding unit will differ. Furthermore, there's a high probability that the path from the specific holding unit to the destination will also differ. However, as described above, the evaluation cost used as an indicator for selecting the target transport vehicle is calculated based on both the reception cost corresponding to the transport vehicle's path until it reaches the specific holding unit and the handover cost corresponding to the path from the specific holding unit to the destination. Therefore, even when the first and second specific sections are included in the path, as in this configuration, the control system can select the optimal transport vehicle as the target transport vehicle.

[0068] Preferably, in calculating the aforementioned receiving cost and the aforementioned handover cost, at least one of the following is used: Distance cost, which increases as the distance the transport vehicle moves becomes longer; The construction cost, which increases as the movable speed of the transport vehicle decreases, corresponds to the construction of the transport vehicle's moving path; Congestion cost, which increases as the degree of congestion existing on the movement path of the transport vehicle increases; Transfer costs, which increase as the time required for the transport vehicle to transfer the article between the article holding unit and the transport destination increases; and The other vehicle cost increases as the number of other transport vehicles present on the movement path of the transport vehicle increases.

[0069] According to this configuration, various costs can 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 handover cost, and further in calculating the evaluation cost, so that the target transport vehicle can be appropriately selected. Industrial applicability

[0070] The technology disclosed herein can be used in article transport equipment including: a plurality of transport vehicles that move along predetermined movement paths to transport articles; and a control system that causes the transport vehicles to perform transport processing that specifies a transport start point and a transport destination for the articles. Description of Reference Numerals

[0071] 100: Goods conveying equipment 1: Transport vehicle 2: Control system 3: Item holding unit 3S: Specific maintenance department 9: Movement Path Cx: Evaluation cost C: Cost Cg: Handover cost Cr: Receiving cost F: conveying starting point T: Delivery destination P: Current location Z: Specific interval Z1: Specific Zone 1 Z2: Specific Zone 2 W: Item.

Claims

1. An article conveying device comprising: a plurality of conveying vehicles that move along a predetermined movement path to convey articles; and a control system that causes the conveying vehicles to perform conveying processing that specifies a conveying start point and a conveying destination of the articles. The article conveying equipment has the following characteristics: Article holding portions capable of holding the articles and allowing the transport vehicle to deliver the articles are disposed at multiple locations along the movement path. At least one of the plurality of article holding sections is a specific holding section from which the article can be delivered from any of the transport vehicles located in a plurality of specific sections of the moving path. The control system is configured as follows: when selecting a target transport vehicle as the transport vehicle to be used for the transport process from among a plurality of transport vehicles that do not hold the article, the control system performs the following selection process: using a value that is a major factor affecting the travel time of the transport vehicle and a cost that increases as the travel time increases, an evaluation cost of each transport vehicle is calculated, and the transport vehicle with the smallest evaluation cost is selected as the target transport vehicle; In the selection process when the specific holding portion is the transport starting point, the evaluation cost is calculated based on both the reception cost, which is the cost corresponding to the moving time of the transport vehicle from the current position to the transport starting point, and the handover cost, which is the cost corresponding to the moving time of the transport vehicle from the transport starting point to the transport destination.

2. The article conveying device according to claim 1, wherein: In the selection process when the article holding unit other than the specific holding unit is the transport starting point, the evaluation cost is calculated based on the reception cost as the cost corresponding to the travel time of the transport vehicle from a current position to the transport starting point.

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

4. The article conveying device according to claim 1 or 2, wherein: In calculating the receiving cost and the handover cost, at least one of the following is used: Distance cost, which increases as the transport vehicle's travel distance increases; Construction costs, which increase as the transport vehicle's movable speed decreases, corresponding to the construction of the transport vehicle's moving path; a congestion cost that increases as the degree of congestion existing on the moving path of the transport vehicle increases; Transfer costs, which increase as the time required for the transport vehicle to transfer the article between the article holding unit and the transport destination increases; and The other vehicle cost increases as the number of other transport vehicles present in the movement path of the transport vehicle increases.

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