Transport vehicle system
The transport vehicle system optimizes the coordination of unmanned vehicles by managing arrival times and paths to prevent conflicts, improving conveyance efficiency and reducing waiting times, achieving a 5% transport time reduction.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MURATA MASCH LTD
- Filing Date
- 2022-08-10
- Publication Date
- 2026-05-19
AI Technical Summary
Existing carrier systems face inefficiencies in reducing waiting times and preventing route conflicts among automated guided vehicles due to potential spatio-temporal route overlaps, leading to decreased conveyance efficiency.
A transport vehicle system with a controller that manages unmanned transport vehicles, utilizing an arrival timing sensing unit and an empty vehicle dispatching unit to coordinate the arrival times of assigned and unassigned vehicles, ensuring they do not interfere, thereby preventing route conflicts and optimizing travel paths.
The system enhances conveyance efficiency by reducing waiting times and preventing route conflicts, allowing vehicles to operate smoothly and efficiently, with a demonstrated 5% improvement in transport time compared to previous methods.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a carrier system.
Background Art
[0002] There is known a carrier system including a plurality of automated guided vehicles traveling along a route and a controller for managing the plurality of automated guided vehicles. In such a carrier system, when a conveyance request occurs, the automated guided vehicle conveys an article from a loading / unloading station at the source of conveyance to a loading / unloading station at the destination of conveyance among a plurality of loading / unloading stations arranged along the route. As this type of technology, for example, Patent Document 1 discloses that an automated guided vehicle that has completed a predetermined operation is caused to travel to a location where the frequency of conveyance requests is high and wait at that location.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In a carrier system, it is desirable to shorten the waiting time (hereinafter also simply referred to as "waiting time") until an automated guided vehicle arrives at a loading / unloading station at the source of conveyance and improve the conveyance efficiency. Therefore, in the above-described technology, it is conceivable to dispatch an idle automated guided vehicle, which is an automated guided vehicle to which no conveyance instruction has been assigned, to the loading / unloading station at the source of conveyance for the next conveyance request. However, in this case, there is an increased possibility of occurrence of a route conflict (deadlock) in which the spatio-temporal routes of the automated guided vehicle to which the previous conveyance request has been assigned and the idle automated guided vehicle conflict with each other in the vicinity of the loading / unloading station.
[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a carrier system capable of improving the conveyance efficiency and preventing the occurrence of route conflicts. [Means for solving the problem]
[0006] (1) The transport vehicle system according to the present invention comprises a plurality of unmanned transport vehicles that travel along a route, and a controller that manages the plurality of unmanned transport vehicles, the controller having an arrival timing sensing unit that grasps the arrival timing of an assigned transport vehicle, which is an unmanned transport vehicle to which a transport command has been assigned, to a transfer station of which transport is the source of transport among a plurality of transfer stations arranged along the route, and an empty vehicle dispatching unit that, based on the arrival timing, dispatches an empty transport vehicle, which is an unmanned transport vehicle to which a transport command has not been assigned, to the transfer station of which transport is the source of transport, so as to arrive later than the arrival timing without interfering with the travel of the assigned transport vehicle.
[0007] This transport vehicle system allows for the dispatch of available transport vehicles to the transfer station at the source of the transport, thus reducing waiting times when, for example, the next transport request arises. Furthermore, by dispatching available transport vehicles to arrive later than the scheduled arrival time without interfering with the movement of assigned transport vehicles, assigned and available transport vehicles can travel smoothly while respecting their respective order, preventing route conflicts where the spatiotemporal paths of assigned and available transport vehicles overlap. Therefore, it is possible to improve transport efficiency and prevent the occurrence of route conflicts.
[0008] (2) In the transport vehicle system described in (1) above, the arrival timing determination unit includes a route search unit that performs a full route search, which collectively searches for a spatiotemporal route from the current position of the assigned transport vehicle to the source transfer station and a spatiotemporal route from the source transfer station to the destination transfer station. The empty vehicle dispatch unit may dispatch an empty transport vehicle to the source transfer station at a later time than the arrival timing, based on the route search results of the route search unit, without interfering with the movement of the assigned transport vehicle. In this case, it is possible to prevent route conflicts by utilizing the search results of the full route search.
[0009] (3) In the transport vehicle system described in (2) above, the empty vehicle dispatch unit may, based on the route search results of the route search unit, dispatch an empty transport vehicle to the transfer station of the transport source so as not to obstruct the movement of the assigned transport vehicle and so as to arrive later than the departure time of the assigned transport vehicle from the transfer station of the transport source. In this case, since the empty transport vehicle is dispatched so as to arrive later than the departure time without obstructing the movement of the assigned transport vehicle, the assigned transport vehicle and the empty transport vehicle can travel more smoothly in accordance with the order of operations, and route conflicts can be further prevented.
[0010] (4) The transport vehicle system described in any one of the above paragraphs (1) to (3) includes non-dedicated waiting points arranged along the route, and the empty vehicle dispatching unit may, if none of the multiple unmanned transport vehicles arrive at the non-dedicated waiting point before the assigned transport vehicle arrives at the transfer station of the transport source, temporarily have the empty transport vehicle wait at the non-dedicated waiting point, and then dispatch the empty transport vehicle that was temporarily waited at the non-dedicated waiting point to the transfer station of the transport source after the assigned transport vehicle arrives at the transfer station of the transport source. In this case, route conflicts can be prevented by using the non-dedicated waiting points.
[0011] (5) In the transport vehicle system described in (2) or (3) above, the route search unit may, when a transport request occurs, selectively perform either a full route search or a partial route search that searches for a spatiotemporal route from the current position of the assigned transport vehicle to the transfer station of the transport source, based on the number of automated guided vehicles (AGVs) present around the transfer station of the transport source. In this case, the computation time required for route search can be reduced according to the number of automated guided vehicles present around the transfer station of the transport source.
[0012] (6) In the transport vehicle system described in any one of the above paragraphs (1) to (5), the route may include a dedicated route for entering one transfer station, and the arrival timing unit may determine the arrival timing of the assigned transport vehicle to the transfer station based on its entry into the dedicated route. In this case, the arrival timing can be determined by utilizing the entry of the assigned transport vehicle into the dedicated route.
[0013] (7) A transport vehicle system described in any one of the above paragraphs (1) to (6) may be equipped with dedicated waiting points arranged along the route, and the empty vehicle dispatching unit may have empty transport vehicles wait at the dedicated waiting points before the assigned transport vehicle arrives at the transfer station of the transport source, and dispatch the empty transport vehicles that have been waiting at the dedicated waiting points to the transfer station of the transport source based on the arrival of the assigned transport vehicle at the transfer station of the transport source. In this case, the dedicated waiting points can be used to dispatch empty transport vehicles to the transfer station of the transport source. [Effects of the Invention]
[0014] According to the present invention, it is possible to provide a transport vehicle system that can improve transport efficiency. [Brief explanation of the drawing]
[0015] [Figure 1] Figure 1 is a schematic diagram showing a transport vehicle system according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram showing an example of the operation of the transport vehicle system shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram showing a continuation of Figure 2. [Figure 4] Figure 4 is a schematic diagram showing a continuation of Figure 3. [Figure 5] Figure 5 is a schematic diagram showing a continuation of Figure 4. [Figure 6] Figure 6 is a schematic diagram showing a continuation of Figure 5. [Figure 7] Figure 7 is a schematic diagram showing an example of the operation of the transport vehicle system according to the second embodiment. [Figure 8] Figure 8 is a schematic diagram showing a continuation of Figure 7. [Figure 9] Figure 9 is a schematic diagram showing an example of the operation of the transport vehicle system according to the third embodiment. [Figure 10] Figure 10 is a schematic diagram showing a continuation of Figure 9. [Figure 11]FIG. 11 is a schematic configuration diagram showing an operation example of the carrier system according to the fourth embodiment. [Figure 12] FIG. 12 is a schematic configuration diagram showing a continuation of FIG. 11. [Figure 13] FIG. 13 is a schematic configuration diagram showing a carrier system according to a modification example.
Embodiments for Carrying out the Invention
[0016] Hereinafter, embodiments will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and duplicate descriptions are omitted. The dimensional ratios in the drawings do not necessarily match those in the description.
[0017] [First Embodiment] As shown in FIG. 1, the carrier system 1 according to the first embodiment is a system that constitutes a conveying system for conveying articles (objects to be conveyed) that have been shipped out from an automatic warehouse 10 within a facility such as a factory. The size, shape, weight, etc. of the articles are not particularly limited, and any object can be applied as an article. The carrier system 1 includes a standby point 2, a plurality of carriers 3, and a controller 4.
[0018] In the facility where the carrier system 1 is introduced, a plurality of transfer stations 11 are installed. The transfer station 11 is a place where articles are placed. The plurality of transfer stations 11 are provided along the path 5 of the carrier 3. The transfer station 11 includes a shipping station 12 that constitutes the shipping port of the automatic warehouse 10, a receiving station 13 that constitutes the receiving port of the automatic warehouse 10, and a picking station 14 provided in the work area 20 within the facility.
[0019] The outbound station 12 is a station that receives goods that have been unloaded from the automated warehouse 10. For example, the outbound station 12 is connected to the automated warehouse 10 by a conveyor. The outbound station 12 is a station designated as the source of transport. The outbound station 12 is a station that is not designated as a destination (it does not receive goods from the transport vehicle 3). The inbound station 13 is a station that receives goods from the transport vehicle 3 and transports them to the automated warehouse 19. For example, the inbound station 13 is connected to the automated warehouse 10 by a conveyor. The inbound station 13 is a station that is not designated as the source of transport (it does not hand over goods to the transport vehicle 3). The picking station 14 is a station for performing predetermined tasks, for example, using a robotic arm. The picking station 14 is a station that is designated as both a source and a destination.
[0020] Waiting point 2 is a location where the transport vehicle 3 can wait. Waiting point 2 is located along the transport vehicle 3's route 5. Waiting point 2 is a stopping position for the transport vehicle 3 to wait, as set in the control system. Waiting point 2 is an area where at least one transport vehicle 3 can stop. Waiting point 2 can be set, for example, in the controller 4.
[0021] The transport vehicle 3 is an unmanned transport vehicle that operates without a driver. The transport vehicle 3 travels, for example, on the floor of the facility. The transport vehicle 3 travels along a predetermined route 5. Route 5 is a route set up in the control system. For example, route 5 is predetermined to pass through the transfer station 11 and the waiting point 2. Route 5 may be a virtual travel path set up based on the position information of the transport vehicle 3. Route 5 may be composed of, for example, magnetic tape (magnetic markers), laser reflectors, floor tracks, ceiling tracks, or rails.
[0022] The transport vehicle 3 is capable of transporting goods from one transfer station 11 to another transfer station 11. The transport vehicle 3 is capable of transferring (receiving) goods between transfer stations 11. An AGV (Automatic Guided Vehicle) is used as the transport vehicle 3. However, the transport vehicle 3 is not particularly limited to an AGV, and may be, for example, an overhead vehicle or a tracked trolley. The transport vehicle 3 may also be a mobile body equipped with a lifting function that operates in three-dimensional space, or a drone that can move freely in three-dimensional space.
[0023] When a transport command (described later) is assigned to the transport vehicle 3 from the controller 4, the transport vehicle 3 performs travel control and loading / unloading control to transport the goods from the source transfer station 11 to the destination transfer station 11 of the transport command. For example, SLAM (Simultaneous Localization and Mapping) technology may be used as the guidance method for travel control. In loading / unloading control, the transport vehicle 3 raises and lowers its lifter to load goods from the transfer station 11 to the transport vehicle 3 and unload goods from the transport vehicle 3 to the transfer station 11.
[0024] Controller 4 is a control device that manages multiple transport vehicles 3. Controller 4 is a computer that has a ROM (Read Only Memory) for storing programs, a RAM (Random Access Memory) for temporarily storing data, a storage medium such as an HDD (Hard Disk Drive), a CPU (Central Processing Unit), and communication circuits such as a wireless LAN. Controller 4 can be configured as software in which, for example, a program stored in ROM is loaded onto RAM and executed by the CPU. Controller 4 may also be configured as hardware using electronic circuits. Controller 4 may consist of one device or multiple devices. If it consists of multiple devices, these are connected via a communication network such as the Internet or an intranet to logically construct a single controller 4.
[0025] Controller 4 is connected to the transport vehicle 3 and the higher-level controller (not shown) by wire or wireless connection. Controller 4 receives information from the transport vehicle 3 regarding the transport vehicle 3's current position and current speed. Controller 4 receives a transport request from the higher-level controller to transport an item from one transfer station 11 to another transfer station 11. Controller 4 generates a transport command in response to the received transport request and assigns the transport command to the transport vehicle 3.
[0026] A transport command is a control command for transporting goods by a transport vehicle 3 from the source transfer station 11 to the destination transfer station 11 in a transport request. The transport command includes information regarding the transfer of goods L at the source transfer station 11, travel along the route 5 from the source transfer station 11 to the destination transfer station 11, and the transfer of goods L at the destination transfer station 11.
[0027] In this embodiment, the controller 4 has a route search unit 41 and an empty vehicle dispatch unit 42. The route search unit 41 performs a full route search, which simultaneously searches for a spatiotemporal route from the current position of the assigned transport vehicle 3A, which is the transport vehicle 3 to which the transport command has been assigned, to the source transfer station 11, and also searches for a spatiotemporal route from the source transfer station 11 to the destination transfer station 11. The spatiotemporal route is the movement trajectory including time, which the transport vehicle 3 is scheduled to travel. The spatiotemporal route is a time-based route with time and the position of the transport vehicle 3 as parameters.
[0028] Such a pathfinding unit 41 can determine the arrival timing (hereinafter also simply referred to as "arrival timing") of the assigned transport vehicle 3A arriving at the transfer station 11, the source of transport, from the results of the entire pathfinding. In other words, the pathfinding unit 41 is included in the arrival timing determination unit. The spatiotemporal pathfinding method used by the pathfinding unit 41 is not particularly limited, and general optimization methods such as Multi-Agent Path Finding, slime mold algorithms, and Dijkstra's algorithm may be applied.
[0029] The empty vehicle dispatch unit 42 assigns a dispatch command to an empty transport vehicle 3B, which is a transport vehicle 3 to which no transport command has been assigned, based on the arrival timing. The dispatch command is issued to the empty transport vehicle 3B to move to a predetermined location when a transport command has already been output (assigned) for an existing transport request and no new transport commands have been generated (i.e., no new transport requests have been issued). The dispatch command is a control command that dispatches the empty transport vehicle 3B to the transfer station 11 (hereinafter, such a transfer station 11 will also be referred to as the "transport source transfer station" or simply the "transport source") which is scheduled to be the source of transport or is highly likely to be the source of transport, so that it arrives (enters) later than the arrival timing without obstructing the movement of the assigned transport vehicle 3A. The dispatch command dispatches an available transport vehicle 3B to the transfer station 11, the source of transport, based on the route search results of the route search unit 41, so as not to obstruct the movement of the assigned transport vehicle 3A and so as to arrive later than the departure time of the assigned transport vehicle 3A from the transfer station 11. The departure time can be determined from the results of the full route search by the route search unit 41.
[0030] A dispatch command can be generated, for example, as follows: First, the route search unit 41 searches for multiple spatiotemporal route candidates from the current position of the empty transport vehicle 3B to the transfer station 11 of the transport source. The empty vehicle dispatch unit 42 selects one of the multiple spatiotemporal route candidates that does not approach within a predetermined distance of the spatiotemporal route of the assigned transport vehicle 3A, and arrives at the transfer station 11 of the transport source later than the arrival timing (in this case, the departure timing), as the spatiotemporal route for the empty transport vehicle 3B. A control command to drive along the determined spatiotemporal route is generated as a dispatch command.
[0031] The predetermined distance corresponds, for example, to the distance at which blocking control (control that prohibits other transport vehicles 3 from entering a predetermined area) is activated. In the dispatch command, dispatching an empty transport vehicle 3B so as not to obstruct the movement of the assigned transport vehicle 3A and arriving at the source vehicle with a delay may be achieved by "delaying the departure timing of the empty transport vehicle 3B", "moving it out of the path that the assigned transport vehicle 3A is traveling on", "having it travel along a spatiotemporal path different from the spatiotemporal path of the assigned transport vehicle 3A", "changing the travel speed of the empty transport vehicle 3B (for example, slowing it down)", "having the empty transport vehicle 3B take a detour or pass through a waiting point to reach the source vehicle", "having the empty transport vehicle 3B temporarily wait during its journey", and at least one combination of these. The method for generating the dispatch command is not particularly limited, and various methods may be applied.
[0032] In the transport vehicle system 1 described above, when a transport request is generated to transport goods from the outbound station 12x (transfer station 11 of the transport source) to the picking station 14x (transfer station 11 of the transport destination), the following example operations are performed.
[0033] In other words, as shown in Figure 2, the controller 4 assigns a transport command to a transport vehicle 3 that meets predetermined conditions in response to a transport request received from a higher-level controller. At this time, the route search unit 41 performs a full route search for the assigned transport vehicle 3A to which the transport command has been assigned, and obtains the spatiotemporal route J1 to the dispatch station 12x and the spatiotemporal route J2 from the dispatch station 12x to the picking station 14x. This makes it possible to determine the arrival timing of the assigned transport vehicle 3A at the dispatch station 12x and the departure timing of the assigned transport vehicle 3A from the dispatch station 12x.
[0034] As shown in Figure 3, after the assignment of a transport command to the assigned transport vehicle 3A and before the assigned transport vehicle 3A arrives at the dispatch station 12x, the dispatch unit 42 assigns a dispatch command to the available transport vehicle 3B waiting at the waiting point 2, and starts dispatching the available transport vehicle 3B to the dispatch station 12x. In this embodiment, the dispatch command to the available transport vehicle 3B may be assigned simultaneously and in parallel with the assignment of the transport command to the assigned transport vehicle 3A. As a result, as shown in Figure 4, the assigned transport vehicle 3A travels along the spatiotemporal path J1 (see Figure 2), arrives at the dispatch station 12x, and begins transferring goods from the dispatch station 12x. The available transport vehicle 3B travels toward the dispatch station 12x.
[0035] After the transfer of goods is complete, the allocation transport vehicle 3A departs from the dispatch station 12x and travels along the spatiotemporal path J2 (see Figure 2) toward the picking station 14x, as shown in Figure 5. After the allocation transport vehicle 3A departs from the dispatch station 12x, the empty transport vehicle 3B arrives at (enters) the dispatch station 12x and waits there. Then, as shown in Figure 6, the allocation transport vehicle 3A arrives at the dispatch station 12x. Meanwhile, the empty transport vehicle 3B remains on standby, preparing for the next transport request originating from the dispatch station 12x.
[0036] As described above, in the transport vehicle system 1, an available transport vehicle 3B can be dispatched to the transfer station 11 at the source of transport. Therefore, for example, when the next transport request is made, it becomes possible to reduce the waiting time until an available transport vehicle 3B arrives at the transfer station 11 at the source of transport. This makes it possible to improve the capacity related to the lead time from the generation of the next transport request to the completion of transport.
[0037] Furthermore, since the empty transport vehicle 3B is scheduled to arrive later than the scheduled arrival time without obstructing the movement of the assigned transport vehicle 3A, the assigned transport vehicle 3A and the empty transport vehicle 3B can travel smoothly while respecting the order of operations, and route conflicts, where the spatiotemporal paths of the assigned transport vehicle 3A and the empty transport vehicle 3B compete, can be prevented. This prevents the assigned transport vehicle 3A, which is carrying goods, from becoming unable to proceed due to the presence of the empty transport vehicle 3B. Therefore, the transport vehicle system 1 makes it possible to improve transport efficiency and prevent the occurrence of route conflicts.
[0038] In the transport vehicle system 1, the route search unit 41 performs a full route search, which simultaneously searches for the spatiotemporal route J1 from the current position of the assigned transport vehicle 3A to the source transfer station 11, and the spatiotemporal route J2 from the source transfer station 11 to the destination transfer station 11. Based on the route search results of the route search unit 41, the empty vehicle dispatch unit 42 dispatches an empty transport vehicle 3B to the source transfer station 11 so that it arrives later than the arrival time of the assigned transport vehicle 3A without interfering with its journey. In this case, it is possible to prevent route conflicts by utilizing the search results of the full route search.
[0039] In the transport vehicle system 1, the empty vehicle dispatch unit 42 dispatches an empty transport vehicle 3B to the transfer station 11, the source of transport, based on the route search results of the route search unit 41, so as not to obstruct the movement of the assigned transport vehicle 3A and so as to arrive later than the departure time of the assigned transport vehicle 3A from the transfer station 11. In this case, since the empty transport vehicle 3B is dispatched so as to arrive later than the departure time without obstructing the movement of the assigned transport vehicle 3A, the assigned transport vehicle 3A and the empty transport vehicle 3B can travel more smoothly while adhering to the order of operations, and route conflicts can be further prevented.
[0040] An evaluation test was conducted to assess the effectiveness of the transport vehicle system 1. In the evaluation test, the transport time required to complete the transport of a predetermined amount of goods was used as the evaluation item. The comparative example in the evaluation test differed from the transport vehicle system 1 in that it searched for a spatiotemporal path J2 and assigned a dispatch command to an available transport vehicle 3B immediately before the departure timing of the assigned transport vehicle 3A from the transport source. As a result of the evaluation test, it was confirmed that the transport vehicle system 1 could improve the transport time by 5 percent compared to the comparative example, and that it could achieve high transport capacity.
[0041] [Second Embodiment] Next, a second embodiment will be described. In this description, explanations that overlap with those of the first embodiment will be omitted.
[0042] As shown in Figure 7, the transport vehicle system 101 according to the second embodiment differs from the first embodiment in that it includes a dedicated waiting point 102. The dedicated waiting point 102 is a waiting point used only when an available transport vehicle 3B is dispatched according to a dispatch command. The dedicated waiting point 102 is not used anywhere other than this waiting point. The dedicated waiting point 102 is arranged along the route 5. The dedicated waiting point 102 is arranged corresponding to each of the dispatch stations 12. For example, the dedicated waiting point 102 is arranged around each dispatch station 12. The dedicated waiting point 102 is a place where a transport vehicle 3 can wait. The dedicated waiting point 102 is a stopping position for the transport vehicle 3 to wait, as set in the control system. The dedicated waiting point 102 is an area where at least one transport vehicle 3 can stop. The dedicated waiting point 102 can be set, for example, in the controller 4.
[0043] In this embodiment, the dispatch command of the empty vehicle dispatch unit 42 causes the empty vehicle 3B to travel to a dedicated waiting point 102 before the assigned transport vehicle 3A arrives at the dispatch station 12x, which is the transfer station 11 from which the transport originates, and causes the empty transport vehicle 3B to wait at the dedicated waiting point 102. As shown in Figure 8, the dispatch command dispatches the empty transport vehicle 3B, which has been waiting at the dedicated waiting point 102, to the dispatch station 12x based on the arrival of the assigned transport vehicle 3A at the dispatch station 12x. Specifically, the dispatch command uses the arrival of the assigned transport vehicle 3A at the dispatch station 12x as a trigger to cause the empty transport vehicle 3B, which has been waiting at the dedicated waiting point 102, to travel to the dispatch station 12x.
[0044] In summary, the transport vehicle system 101 also achieves the above-mentioned effects of improving transport efficiency and preventing route conflicts. Furthermore, the transport vehicle system 101 can utilize the dedicated waiting point 102 to dispatch available transport vehicles 3B to the dispatch station 12x.
[0045] In this embodiment of the dispatch command, the available transport vehicle 3B should arrive at the dispatch station 12x later than the assigned transport vehicle 3A and wait there so as not to interfere with the movement of the assigned transport vehicle 3A. The arrival and waiting of the available transport vehicle 3B at the dedicated waiting point 102 does not have to be before the available transport vehicle 3B arrives at the dispatch station 12x, but can be done before the next transport request is generated.
[0046] [Third Embodiment] Next, a third embodiment will be described. In this embodiment, explanations that overlap with those of the first embodiment will be omitted.
[0047] As shown in Figure 9, the transport vehicle system 201 according to the third embodiment differs from the first embodiment in that the route 5 includes an entry-only route 205 and an exit-only route 206. The entry-only route 205 is a route used only for entering the transfer station 11. The exit-only route 206 is a route used only for exiting the transfer station 11. The entry-only route 205 is a one-way road that can only proceed in the direction approaching the transfer station 11. The exit-only route 206 is a one-way road that can only proceed in the direction away from the transfer station 11.
[0048] The controller 4 further includes an entry detection unit 243. The entry detection unit 243 detects the entry of the assigned transport vehicle 3A onto the dedicated entry route 205 based on information regarding its current position received from the assigned transport vehicle 3A. Based on the entry of the assigned transport vehicle 3A onto the dedicated entry route 205 detected by the entry detection unit 243, the controller 4 determines the arrival timing of the vehicle's arrival at the transfer station 11. For example, the controller 4 can obtain the arrival timing based on the current speed and the length of the dedicated entry route 205 received from the assigned transport vehicle 3A. The controller 4, including such an entry detection unit 243, constitutes an arrival timing determination unit.
[0049] In this embodiment, the dispatch command of the empty vehicle dispatch unit 42 dispatches an empty vehicle 3B to the dispatch station 12x based on the fact that the assigned vehicle 3A has entered the entry-only route 205, as shown in Figure 10. Specifically, the dispatch command uses the entry of the assigned vehicle 3A into the entry-only route 205 as a trigger to drive the empty vehicle 3B to the dispatch station 12x. Alternatively, the empty vehicle 3B could be kept waiting at the waiting point 2, and the waiting empty vehicle 3B could be dispatched based on the fact that the assigned vehicle 3A has entered the entry-only route 205.
[0050] In summary, the transport vehicle system 201 also achieves the above-mentioned effects, such as improving transport efficiency and preventing route conflicts. Furthermore, the transport vehicle system 201 makes it possible to determine the arrival timing by utilizing the entry of the assigned transport vehicle 3A into the dedicated entry route 205.
[0051] [Fourth Embodiment] Next, a fourth embodiment will be described. In this embodiment, explanations that overlap with those of the first embodiment will be omitted.
[0052] As shown in Figure 11, the transport vehicle system 301 according to the fourth embodiment differs from the first embodiment in that it includes a receiving station 13 as a non-dedicated waiting point 313. The non-dedicated waiting point 313 constitutes a waiting point used not only as a receiving station 13 but also when dispatching an available transport vehicle 3B according to a dispatch command. The non-dedicated waiting point 313 can be set, for example, in the controller 4.
[0053] In this embodiment, the dispatch command of the empty vehicle dispatch unit 42 states that if no other transport vehicles 3 arrive at the non-dedicated waiting point 313 before the assigned transport vehicle 3A arrives at the dispatch station 12x, which is the transfer station 11 from which the transport originates, an empty transport vehicle 3B is temporarily placed on standby at the non-dedicated waiting point 313. That is, if there is another transport vehicle 3 traveling to the receiving station 13 as its destination (transport destination), that transport vehicle 3 will become an empty transport vehicle 3B once it unloads at the receiving station 13. However, in this embodiment, it is assumed that the frequency of departures from the dispatch station 12x is greater than the frequency of arrivals at the receiving station 13, and that no other transport vehicles traveling to the receiving station 13 as its destination will occur before the next transport request originating from the dispatch station 12x. In such a case, in this embodiment, an empty transport vehicle 3B is dispatched to the receiving station 13, which is the non-dedicated waiting point 313, and placed on standby.
[0054] In the dispatch command of this embodiment, after the assigned transport vehicle 3A arrives at the dispatch station 12x, an available transport vehicle 3B, which has been temporarily waiting at the non-dedicated waiting point 313, is dispatched to the dispatch station 12x. For example, as shown in Figure 12, in the dispatch command, after the assigned transport vehicle 3A has arrived at the dispatch station 12x and has moved a predetermined distance or more away from the non-dedicated waiting point 313, the available transport vehicle 3B, which has been temporarily waiting at the non-dedicated waiting point 313, is dispatched to the dispatch station 12x.
[0055] As described above, the transport vehicle system 301 also achieves the above-mentioned effects of improving transport efficiency and preventing route conflicts. Furthermore, while there is often limited space around the outbound station 12x of the automated warehouse 10, making it difficult to secure waiting points, the transport vehicle system 301 allows the inbound station 13 to be used as a temporary non-dedicated waiting point 313. This makes it possible to prevent route conflicts by utilizing the non-dedicated waiting point 313. Note that the non-dedicated waiting point 313 is not particularly limited and may be any other transfer station 11 or any other location.
[0056] [Differentiation] Although embodiments have been described above, one aspect of the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention.
[0057] In the above embodiment, the layout of the route 5 is not particularly limited and may be in various configurations. In the above embodiment, the number and arrangement of the transfer stations 11 and the number and arrangement of the waiting points 2 are not particularly limited and may be in various configurations. For example, as shown in Figure 13, a modified transport vehicle system 401 may include a route 5 that includes a circular circuit 51. In such a transport vehicle system 401, when transporting goods from the outbound station 12x to the picking station 14x, the assigned transport vehicle 3A can be driven along a spatiotemporal route J2 that takes the shortest time to reach the destination, preventing the assigned transport vehicle 3A from taking a roundabout route to the destination.
[0058] In the above embodiment, the arrival of the assigned transport vehicle 3A at the transfer station 11 is detected by a sensor, and the controller 4 determines the arrival timing based on the detection result. In this case, the sensor and the controller 4 constitute the arrival timing determination unit.
[0059] In the above embodiment, when a transport request occurs, the route search unit 41 may selectively perform either the full route search described above or a partial route search that searches for the spatiotemporal route J1 from the current position of the assigned transport vehicle 3A to the source transfer station 11, based on the number of transport vehicles 3 present around the source transfer station 11. For example, when a transport request occurs, if the number of transport vehicles 3 in a predetermined area around the source transfer station 11 is greater than or equal to a specified number, the full route search described above may be performed; if the number is less than the specified number, the partial route search described above may be performed. In this case, the calculation time required for route search, the calculation cost, and the risk of revising the plan can be reduced according to the number of transport vehicles 3 present around the source transfer station 11.
[0060] Each component in the above embodiments or modifications can be arbitrarily applied to each component in other embodiments or modifications. Some components in the above embodiments or modifications can be omitted as appropriate without departing from the spirit of one aspect of the present invention. The present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. [Explanation of symbols]
[0061] 1, 101, 201, 301, 401… Transport vehicle system, 3… Transport vehicle (unmanned transport vehicle), 3A… Assigned transport vehicle, 3B… Empty transport vehicle, 4… Controller (arrival timing tracking unit), 5… Route, 11… Transfer station, 12, 12x… Outbound station, 13… Inbound station, 14, 14x… Picking station, 41… Route search unit (arrival timing tracking unit), 102… Dedicated waiting point, 205… Dedicated entry route, 243… Entry detection unit (arrival timing tracking unit), 313… Non-dedicated waiting point, J1, J2… Spatiotemporal route.
Claims
1. Multiple automated guided vehicles traveling along the route, A controller for managing multiple automated guided vehicles, The aforementioned controller, An arrival timing unit that determines the arrival timing of an assigned transport vehicle, which is an automated guided vehicle to which a transport command has been assigned, when it arrives at the transfer station of the transport source among a plurality of transfer stations arranged along the route, The system includes an empty vehicle dispatching unit that, based on the aforementioned arrival timing, dispatches an empty vehicle, which is an unmanned transport vehicle to which no transport command has been assigned, to the transfer station at the transport source so as to arrive later than the aforementioned arrival timing without interfering with the movement of the assigned transport vehicle. The aforementioned arrival timing determination unit, The system includes a route search unit that performs a full route search, which collectively searches for a spatiotemporal route from the current position of the assigned transport vehicle to the transfer station of the transport source, and a spatiotemporal route from the transfer station of the transport source to the transfer station of the transport destination. The aforementioned vehicle dispatching unit is A transport vehicle system that, based on the route search results of the route search unit, determines from among a plurality of spatiotemporal route candidates from the current position of the empty transport vehicle to the transfer station of the transport source, which arrives at the transfer station of the transport source later than the arrival timing, as the spatiotemporal route, and assigns a dispatch command to the empty transport vehicle to travel along the determined spatiotemporal route.
2. The transport vehicle system according to claim 1, wherein the empty transport vehicle dispatch unit dispatches the empty transport vehicle to the transfer station of the transport source based on the route search result of the route search unit, so as not to obstruct the movement of the assigned transport vehicle and so as to arrive later than the departure timing of the assigned transport vehicle when it departs from the transfer station of the transport source.
3. Multiple automated guided vehicles traveling along a route, A controller for managing multiple automated guided vehicles, The aforementioned controller, An arrival timing unit that determines the arrival timing of an assigned transport vehicle, which is an automated guided vehicle to which a transport command has been assigned, when it arrives at the transfer station of the transport source among a plurality of transfer stations arranged along the route, The system includes an empty vehicle dispatching unit that, based on the aforementioned arrival timing, dispatches an empty vehicle, which is an unmanned transport vehicle to which no transport command has been assigned, to the transfer station at the transport source so as to arrive later than the aforementioned arrival timing without interfering with the movement of the assigned transport vehicle. The system includes non-dedicated waiting points arranged along the aforementioned route, The aforementioned vehicle dispatching unit is If none of the multiple automated guided vehicles arrive at the non-dedicated waiting point before the assigned guided vehicle arrives at the transfer station of the source of transport, the available guided vehicle will be temporarily placed to wait at the non-dedicated waiting point. A transport vehicle system that, after the assigned transport vehicle arrives at the transfer station of the transport source, dispatches the available transport vehicles, which have been temporarily waiting at the non-dedicated waiting point, to the transfer station of the transport source.
4. The aforementioned path search unit, The transport vehicle system according to claim 1 or 2, wherein when a transport request occurs, either the full route search or a partial route search, which searches for a spatiotemporal route from the current position of the assigned transport vehicle to the transfer station of the transport source, is selectively performed based on the number of unmanned transport vehicles present around the transfer station of the transport source.
5. The aforementioned route includes a dedicated access route to one of the aforementioned transfer stations. The transport vehicle system according to claim 1 or 2, wherein the arrival timing determination unit determines the arrival timing of the assigned transport vehicle to one of the transfer stations based on the vehicle's entry into the dedicated entry route.
6. Multiple automated guided vehicles traveling along a route, A controller for managing multiple automated guided vehicles, The aforementioned controller, An arrival timing unit that determines the arrival timing of an assigned transport vehicle, which is an automated guided vehicle to which a transport command has been assigned, when it arrives at the transfer station of the transport source among a plurality of transfer stations arranged along the route, The system includes an empty vehicle dispatching unit that, based on the aforementioned arrival timing, dispatches an empty vehicle, which is an unmanned transport vehicle to which no transport command has been assigned, to the transfer station at the transport source so as to arrive later than the aforementioned arrival timing without interfering with the movement of the assigned transport vehicle. The system includes dedicated waiting points arranged along the aforementioned route, The aforementioned vehicle dispatching unit is Before the assigned transport vehicle arrives at the transfer station of the transport source, the available transport vehicles are made to wait at the dedicated waiting point. A transport vehicle system that, based on the arrival of the assigned transport vehicle at the transfer station of the transport source, dispatches the available transport vehicles, which have been waiting at the dedicated waiting point, to the transfer station of the transport source.