Route generation system

Abstract

This route generation system includes a controller that generates a route in which a carrier vehicle travels from the departure point to the destination in a travel area. The controller: sets first blocks divided into three or more and second blocks connected to the first blocks with respect to a plurality of points in the travel area; extracts points included in a transport source block that is one among the first blocks to which the departure point belongs, in a transport destination block that is one among the first blocks to which the destination belongs, and in the second blocks; and generates a route from the extracted points.

Description

Route Generation System

[0001] The present disclosure relates to a route generation system that generates a travel route for a guided vehicle.

[0002] Conventionally, there have been known route planning devices and transport systems that quickly create route plans that minimize the total transport time or total transport distance of multiple automated guided vehicles (AGVs) traveling from an initial point to a destination point (see, for example, Patent Document 1).

[0003] Patent No. 4138541

[0004] The conventional system described above creates route plans for all guided vehicles in a short calculation time, but when the travel area becomes large, the route plan calculations become enormous. Conventional systems do not take this into consideration, and route planning for a vast travel area requires a huge calculation load. In some cases, the amount of memory used for route search may reach the upper limit of available memory, making it impossible to generate a route.

[0005] The present disclosure describes a route generation system that can reduce the load required for route generation even in vast travel areas.

[0006] One aspect of the present disclosure is a route generation system that generates a route for one or more transport vehicles to travel from a departure point to a destination in a travel area, the system including a controller that generates a route for the transport vehicles to travel, the travel area having a plurality of points at which the transport vehicles can pass and stop, the controller sets three or more divided first blocks and second blocks connected to the first blocks for the plurality of points, extracts a source block which is one of the first blocks to which the departure point belongs, a destination block which is one of the first blocks to which the destination belongs, and points included in the second block, and generates a route from the extracted points.

[0007] According to this route generation system, the controller sets three or more divided first blocks and the second blocks connected to them. That is, multiple points in the travel area are divided into any of these blocks. The controller extracts points included in the source block, destination block, and second block of the three or more first blocks, and generates a route from among them. In this way, the areas (points) searched by the controller during route generation are narrowed (limited) to a portion of the travel area rather than the entire travel area (all points). This reduces the load required for route generation even in vast travel areas.

[0008] The second block may be set to include points with a high passing frequency based on a simulation of all transport patterns, in which case the second block can be set appropriately in accordance with the actual environment.

[0009] The controller may set the second block individually for each of the routes on which the plurality of guided vehicles travel. By changing the second block for each of the guided vehicles, it is possible to reduce the frequency of interference between the guided vehicles.

[0010] An upper limit may be set on the number of points included in each of the first blocks, in which case the number of areas (points) searched by the controller when generating a route is reduced, further reducing the load required for route generation.

[0011] At least one of the plurality of points in the travel area may be connected to only three or fewer paths, and the second block may include the at least one point.

[0012] The second block may include a plurality of points, each having four or more paths connected thereto.

[0013] According to the present disclosure, the load required for route generation can be reduced even in vast travel areas.

[0014] FIG. 1 is an overall schematic diagram of an automated guided vehicle system to which a path generation system according to the present disclosure is applied. FIG. 2(a) is a diagram showing a travel area (travel route), and FIG. 2(b) is a diagram showing one unit thereof. FIG. 3 is a functional block diagram showing the functional configuration of a controller according to an embodiment. FIG. 4 is a diagram illustrating a plurality of first blocks and one second block set by the controller. FIG. 5 is a diagram illustrating an area searched by the controller during path generation. FIG. 6 is a diagram showing a travel area and first and second blocks according to a first modified example. FIGS. 7(a) and 7(b) are diagrams showing a travel area and first and second blocks according to second and third modified examples, respectively. FIGS. 8(a) and 8(b) are diagrams showing a travel area and first and second blocks according to fourth and fifth modified examples, respectively. FIG. 9 is a diagram showing a travel area and first and second blocks according to a sixth modified example.

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicated description will be omitted.

[0016] First, with reference to FIG. 1 , an automated guided vehicle system 1 to which a path generation system 6 (see FIG. 3 ) of this embodiment is applied will be described. As shown in FIG. 1 , the automated guided vehicle system 1 is, for example, a transport system that transports articles within a building 100. The automated guided vehicle system 1 includes a plurality of automated guided vehicles 10 that transport articles and a travel area A in which the automated guided vehicles 10 travel. In the example shown in FIG. 1 , for example, three processing devices (a first processing device 31, a second processing device 32, and a third processing device 33), an unloading station 34, and a carrying-in station 35 are provided within the building 100. The travel area A is provided in an area excluding the first processing device 31 to the third processing device 33, the unloading station 34, and the carrying-in station 35. The articles handled by the automated guided vehicle system 1 may be parts, products, or the like that can be transported by each automated guided vehicle 10, and are not particularly limited. Hereinafter, the automated guided vehicle system 1 will be abbreviated as "guide vehicle system 1", and the automated guided vehicle 10 will be abbreviated as "guide vehicle 10".

[0017] In the guided vehicle system 1, the first processing device 31 to the third processing device 3, the carry-out station 34, and the carry-in station 35 are each arranged so that an article can be transferred thereto by a guided vehicle 10 traveling along a predetermined path within a travel area A. The guided vehicle system 1 may also include one or more automated warehouses (not shown) that store a plurality of articles. The automated warehouse may have storage shelves capable of storing a plurality of articles, a stacker crane that transfers articles to and from the storage shelves, and a plurality of input / output ports through which articles can be transferred by the guided vehicle 10 (none of which are shown). The number and arrangement of the processing devices and the travel area A may be freely determined and are not limited to the example shown in FIG. 1 .

[0018] The transport vehicle 10 travels autonomously along a preset route 2. The transport vehicle 10 is, for example, an AGV (Automated Guided Vehicle).

[0019] The configuration of the travel area A will be described with reference to FIGS. 2( a) and 2(b). The travel area A is a two-dimensional area on the floor (travel surface) and is an area in which each guided vehicle 10 can travel. The travel area A has a large number (plurality) of points P where each guided vehicle 10 can pass and stop, and a plurality of segments (paths) S between these points P (specifically, between two adjacent points P) and connecting these points P. Each point P may be provided with a code such as a barcode or two-dimensional code so that the travel control unit 15 of each guided vehicle 10 can detect its own position. Each guided vehicle 10 has a reading device (not shown). If a two-dimensional code is provided, each guided vehicle 10 detects its own position by reading information from the two-dimensional code. The two-dimensional code may include information for identifying the direction. Alternatively, the two-dimensional code may not include information for identifying the direction, and each guided vehicle 10 may have an orientation detection means such as a compass for determining the orientation (travel direction) of its own vehicle.

[0020] The guided vehicle 10 may travel while detecting magnetic signals output from magnetic tape, magnetic markers, or the like. Alternatively, the guided vehicle 10 may travel while detecting its own position by generating light from a laser or the like and detecting the light reflected by a mirror attached to the wall of a building, or may travel while detecting its own position using information from a GPS or the like. SLAM (Simultaneous Localization and Mapping) technology may be used as a guidance method for the guided vehicle 10. The guided vehicle system 1 may be provided with a charging point or charging station for supplying power to the guided vehicle 10.

[0021] Each linear segment S indicated by a dashed line in the figure has a length, i.e., a section length, equivalent to the distance (pitch) between two points P. The section length of each segment S may be constant within the travel area A, but it does not have to be constant. The section length of some segments S may be longer than the (average) section length of many other segments S, or conversely, it may be shorter. In the guided vehicle system 1, to achieve stable travel, for example, an upper limit is set on the length of the segment S, i.e., the section length. The upper limit on the section length is, for example, approximately 1000 mm to 3000 mm.

[0022] As shown in FIG. 2B , each point P is associated with a spin turn time (seconds) as information necessary for searching and generating a travel path for the guided vehicle 10. The spin turn time (seconds) is set to a specific time (turn time) for two cases: when the guided vehicle 10 stops at the point P and makes a 90-degree spin turn, and when the guided vehicle 10 makes a 180-degree spin turn. Each segment S is also associated with a section length (mm) and a travel speed (mm / second). From these two pieces of information, the time required for the guided vehicle 10 to travel the segment S (travel time) is calculated. The turn time and travel time are indices used in the route search process by the route generation unit 14 (described later), and are also "costs" from another perspective. Each point P may also be referred to as a "stop point."

[0023] As shown in FIG. 3, the guided vehicle system 1 has a plurality of guided vehicles 10 each traveling in a travel area A and a starting point P ｆｒｏｍ From destination P ｔｏ The system includes a route generation system 6 that generates a travel route R for travelling to the starting point P. ｆｒｏｍ and destination P ｔｏ are any two points P within the travel area A.

[0024] As shown in Figure 3, the route generation system 6 includes a plurality of transport vehicles 10 that transport items, a transport vehicle controller 20 that controls the plurality of transport vehicles 10, and a host controller 5 that issues transport requests to the transport vehicle controller 20.

[0025] When a transportation command (described later) is assigned from the transportation vehicle controller 20, the transportation vehicle 10 ｆｒｏｍ From destination P ｔｏ In the route generation system 6, the transport vehicle controller 20 and the transport vehicle 10 cooperate to execute travel control and loading / unloading control for transporting the article to the starting point P ｆｒｏｍ From destination P ｔｏ In other words, the controller function of generating the travel route R is distributed between the transport vehicle controller 20 and the transport vehicle 10. In the loading and unloading control, the lifter of the transport vehicle 10 is raised and lowered to load the transport vehicle 10 from each processing device or transfer station, and unload the transport vehicle 10 to each processing device or transfer station.

[0026] The guided vehicle controller 20 is a control device that manages multiple guided vehicles 10. The guided vehicle controller 20 is a computer that includes a read-only memory (ROM) that stores programs and the like, a random access memory (RAM) that temporarily stores data, a storage medium such as a hard disk drive (HDD), a processor such as a central processing unit (CPU), and a communication circuit such as a wireless LAN. The guided vehicle controller 20 can be configured as software in which a program stored in the ROM is loaded onto the RAM and executed by the CPU. The guided vehicle controller 20 may also be configured as hardware such as electronic circuits. The guided vehicle controller 20 may be configured as a single device or multiple devices. When configured as multiple devices, these devices are connected via a communication network such as the Internet or an intranet to logically form a single guided vehicle controller 20.

[0027] The transport vehicle controller 20 is connected to the transport vehicle 10 and the host controller 5 by wire or wirelessly. The transport vehicle controller 20 receives information from the transport vehicle 10, such as the current position and current speed of the transport vehicle 10. The transport vehicle controller 20 receives a transport request from the host controller 5 to transport an item from one processing device to another. A transport request is generated, for example, when an item arrives at the end of an outgoing conveyor, or when an item arrives at a dispensing station after processing in upstream equipment is completed. The transport vehicle controller 20 generates a transport command in response to the received transport request and assigns the transport command to the transport vehicle 10.

[0028] The transport command is a control command for transporting an article from the source transfer station in the transport request to the destination transfer station by the transport vehicle 10. The transport command includes information regarding the transfer of the article at the source transfer station, traveling along the route 2 from the source transfer station to the destination transfer station, and the transfer of the article at the destination transfer station.

[0029] As shown in FIG. 3, the transport vehicle controller 20 includes a transport request receiving unit 21, an information acquiring unit 23, a first block setting unit 24, an allocation determining unit 25, and a storage unit 27. The transport request receiving unit 21 receives a transport request from the upper controller 5 and generates a transport command in response to the received transport request. The information acquiring unit 23 acquires information about the travel area A and information about the travel status of all transport vehicles 10. The allocation determining unit 25 assigns, to the transport request, an empty transport vehicle (empty automatic transport vehicle), which is a transport vehicle 10 that is not currently executing another transport request. The first block setting unit 24 will be described later. The storage unit 27 stores information about the divided blocks B1a to B1e (first blocks; see FIG. 4) set by the first block setting unit 24 for the travel area A.

[0030] The transport vehicle 10 has functions related to the travel control of the transport vehicle itself, including a transport command receiving unit 11, an area information acquiring unit 12, a second block setting unit 13, a route generating unit 14, and a travel control unit 15. The transport command receiving unit 11, the area information acquiring unit 12, the second block setting unit 13, the route generating unit 14, and the travel control unit 15 are also configured to include storage media such as ROM, RAM, and HDD, a processor such as a CPU, and a communication circuit such as a wireless LAN. The transport command receiving unit 11 receives a transport command transmitted from the allocation determination unit 25 of the transport vehicle controller 20. The area information acquiring unit 12 acquires information related to the travel area A. The information acquired by the information acquiring unit 23 of the transport vehicle controller 20 and the area information acquiring unit 12 of the transport vehicle 10 includes information related to the above-mentioned points P and segments S. The second block setting unit 13 will be described later. The route generation unit 14 generates a driving route R for the vehicle based on the divided blocks B1a to B1e set by the first block setting unit 24 and the shared block B2 set by the second block setting unit 13.

[0031] 3, 4, and 5, the setting of each block in the route generation system 6 and the generation of the travel route R will be described. When generating the travel route R for each transport vehicle 10 that is to execute a transport request, the route generation system 6 does not target all points P in the travel area A as the target of route search, but targets only some of the points P.

[0032] As shown in FIGS. 3 and 4 , the first block setting unit 24 of the guided vehicle controller 20 sets three or more divided blocks B1a to B1e for all points P within the travel area A. For example, five divided blocks B1a to B1e exist to divide the travel area A. An upper limit, for example, is set for the number of points P included in each of the divided blocks B1a to B1e. The upper limit number of points P that can be included in each divided block may be set to, for example, less than 50, less than 100, or less than 200. The upper limit number may be determined based on the size of the travel area A. The upper limit number may be determined based on the computing power or performance of the memory in the guided vehicle controller 20. The number of divided blocks is not particularly limited, but in the example shown in FIG. 4 , the divided blocks are set so that the number of points P included in each divided block is approximately 9 to 17. For example, the divided blocks are set based on the loading station and unloading station of each processing device, so that multiple points located around the loading station and unloading station belong to one divided block.

[0033] The second block setting unit 13 of the transport vehicle 10 sets a shared block (second block) B2 so as to include a frequently passed point P based on a simulation of all transport patterns, as a preparation for the route generation unit 14 to generate the travel route R. The shared block B2 is connected to the divided blocks B1a to B1e via a plurality of segments S.

[0034] The first block setting unit 24 of the transport vehicle controller 20 may set divided blocks B1a to B1e by dividing an area other than the shared block B2 after the shared block B2 is set by the second block setting unit 13. The divided blocks (first blocks) and the shared blocks (second blocks) are set separately.

[0035] 4 shows the block setting X1 in this embodiment. As shown in FIG. 4, in the current transport command (transport request), points P included in shared block B2 are assigned numbers from 3000 to 3100. Points P included in divided blocks B1a to B1e are assigned numbers other than 3000 to 3100. For example, divided block B1a is assigned numbers from 3201 to 3300, divided block B1b is assigned numbers from 3301 to 3500, divided block B1c is assigned numbers from 3501 to 3700, divided block B1d is assigned numbers from 3701 to 3900, and divided block B1e is assigned numbers from 3901 to 4100.

[0036] 4, the shared block B2 includes a plurality of points P, each of which is connected to three or fewer segments S. In particular, in this embodiment, the shared block B2 includes only a plurality of points P, each of which is connected to three or fewer segments S. For example, the shared block B2 includes a first-type point P1, which is connected to only one segment S, a second-type point P2, which is connected to only two segments S, and a third-type point P3, which is connected to only three segments S. The shared block B2 is set as an area that must be passed through when traveling between different divided blocks.

[0037] 5, the route generating unit 14 of the transport vehicle 10 determines the route of the starting point P ｆｒｏｍ (No. 3304) belongs to divided block B1b (source block), destination P ｔｏThe divided block B1e (destination block) to which (No. 4001) belongs and the points P included in the shared block B are extracted, and a travel route R is generated from these. The route generation unit 14 finds the shortest route by using a known method such as the Dijkstra algorithm as a route search algorithm. The Dijkstra algorithm always finds the shortest route. Other divided blocks are not used in the route search (they are treated as if they do not exist).

[0038] As a result of the route search, the route generation unit 14 generates a travel route R indicated by a thick arrow in Fig. 5. The travel route R is made up of a source route R1b generated in the divided block B1b, a shared route R2 generated in the shared block B2, and a destination route R1e generated in the divided block B1e.

[0039] The setting of three or more divided blocks (first blocks) and the setting of one or more shared blocks (second blocks) may be performed offline when creating the map data.

[0040] The travel control unit 15 causes the transport vehicle 10 to travel along the travel route R generated by the route generation unit 14 .

[0041] According to the guided vehicle system 1 and the route generation system 6 of this embodiment, the first block setting unit 24 sets three or more divided blocks B1a to B1e, and the second block setting unit 13 sets the shared block B2. That is, all points P in the travel area A are divided into one of these blocks. The route generation unit 14 sets the starting point P among the divided blocks B1a to B1e. ｆｒｏｍ the divided block B1b (transport source block) to which the ｔｏ The divided block B1e (destination block) to which the vehicle belongs and the points P included in the shared block B are extracted, and a travel route R is generated from these. In this way, the area (points P) searched by the route generation unit 14 during route generation is narrowed down (limited) to a portion of the travel area A rather than the entire travel area A (all points). This reduces the load required for route generation even in a vast travel area A.

[0042] The shared block B2 is set based on a simulation of all transport patterns so as to include a point P with a high passing frequency. This allows the shared block B2 to be set appropriately in accordance with the actual environment.

[0043] The second block setting unit 13 sets a shared block B2 individually for each travel route R on which each of the transport vehicles 10 travels. By changing the shared block B2 for each of the transport vehicles 10, it is possible to reduce the frequency of interference between the transport vehicles 10.

[0044] An upper limit is set for the number of points P included in each of the divided blocks B1a to B1e. This reduces the number of areas (points P) that the route generation unit 14 searches when generating a route, thereby further reducing the load required for route generation.

[0045] Although the embodiments of the present disclosure have been described above, the present invention is not limited to the above embodiments. For example, depending on the configuration of the travel area A (the number and arrangement of points P, the number, length, and arrangement of segments S) and the size (scale) of the travel area A, three or more divided blocks (first blocks) and one or more shared blocks (second blocks) may be set in different ways.

[0046] For example, as shown in block setting X2 in FIG. 6 , five divided blocks B1a-B1e are connected to one another and formed as an L-shaped block overall, and a single shared block B2 may be set that connects the centers of the five divided blocks B1a-B1e in an L-shaped line. In this case, the shared block B2 includes multiple points P, each of which is connected to four or more segments S. While one transport vehicle 10 sets such a shared block B2, another transport vehicle 10 may set a different shared block (e.g., a block that is shifted in position from the shared block B2 in FIG. 6 ). Note that in FIG. 6 and subsequent figures, the points P are not shown, and the positions of the points P are represented as lattice points.

[0047] Also, as in block setting X3 shown in Figure 7(a), a single shared block B2 may connect four divided blocks B1a to B1d. As in block setting X4 shown in Figure 7(b), a cross-shaped shared block B2 may connect four divided blocks B1a to B1d. As in block setting X5 shown in Figure 8(a), block settings X3 and X4 may be combined to connect each divided block to all other divided blocks via shared blocks B2a and B2b. As in block setting X6 shown in Figure 8(b), only some divided blocks may be connected to all other divided blocks via shared blocks B2a and B2b.

[0048] As in block setting X7 shown in FIG. 9, a shared block B2a may connect divided blocks B1a and B1b, and this may be the base block from which a shared block B2b may connect four divided blocks B1c to B1f.

[0049] In the above embodiment, the transportation vehicle controller 20 and the transportation vehicle 10 cooperate to ｆｒｏｍ From destination P ｔｏ The embodiment of generating the travel route R to the transport vehicle 10 has been described. However, the travel route R may be generated only by the transport vehicle controller 20, only by a controller provided in the transport vehicle 10, or only by a controller provided separately from the transport vehicle controller 20 and the transport vehicle 10. The travel route R may be generated by the transport vehicle controller 20 and another controller working together, or the travel route R may be generated by the controller provided in the transport vehicle 10 and another controller working together.

[0050] The guided vehicle system 1 may include only one guided vehicle 10, and the path generation system 6 may generate a travel path R for the single guided vehicle 10. The guided vehicle 10 is not particularly limited to an AGV, and may be, for example, an overhead traveling vehicle, a rail-guided vehicle, or the like.

[0051] The constituent features of the present invention can be described as follows. [1] A route generation system that generates a route for one or more guided vehicles to travel from a departure point to a destination in a travel area, comprising: a controller that generates the route along which the guided vehicles travel; the travel area has a plurality of points at which the guided vehicles can pass and stop; the controller sets three or more divided first blocks and second blocks connected to the first blocks for the plurality of points; and extracts the points included in a source block, which is one of the first blocks to which the departure point belongs, a destination block, which is one of the first blocks to which the destination belongs, and the second blocks, and generates the route from the extracted points. [2] The route generation system described in [1], in which the second block is set to include a point with a high passage frequency based on a simulation of all transportation patterns. [3] The route generation system described in [1] or [2], in which the controller sets the second block individually for the route along which each of the plurality of guided vehicles travels. [4] The route generation system according to any one of [1] to [3], wherein an upper limit is set on the number of points included in each of the first blocks. [5] The route generation system according to any one of [1] to [4], wherein at least one of the plurality of points in the traveling area is connected to three or fewer paths, and the second block includes the at least one point. [6] The route generation system according to any one of [1] to [4], wherein the second block includes a plurality of points, each connected to four or more paths.

[0052] 1...Transport vehicle system (automated guided vehicle system), 5...Host controller, 6...Route generation system, 10...Transport vehicle (automated guided vehicle), 11...Transport command receiving unit, 12...Area information acquisition unit, 13...Second block setting unit, 14...Route generation unit, 15...Travel control unit, 20...Transport vehicle controller, 21...Transport request receiving unit, 23...Information acquisition unit, 24...First block setting unit, 25...Allocation determination unit, A...Travel area, B1a, B1b, B1c, B1d, B1e, B1f,...Divided blocks (first blocks), B2...Shared block (second block), P...Point, P ｆｒｏｍ …Departure point, P ｔｏ ...destination, R...travel route, R1b...source route, R1e...destination route, R2...shared route, S...segment (passage).

Claims

1. A route generation system that generates a route for one or more transport vehicles to travel from a starting point to a destination within a travel area, The system includes a controller that generates the route on which the transport vehicle travels, The aforementioned travel area has multiple points through which the transport vehicle can pass and stop. The aforementioned controller, For the aforementioned multiple points, a first block divided into three or more sections and a second block connected to the first block are set. Extract the source block which is one of the first blocks to which the departure point belongs from the first block, the destination block which is one of the first blocks to which the destination belongs from the first block, and the points included in the second block, and generate the route from the extracted points, The second block is a route generation system configured to include frequently traversed points based on a simulation of all transport patterns.

2. The route generation system according to claim 1, wherein the controller individually sets the second block for each of the multiple transport vehicles that travel along the route.

3. The route generation system according to claim 1 or 2, wherein an upper limit is set on the number of points included in each of the first blocks.

4. At least one of the multiple points within the aforementioned driving area is connected to only three or fewer passages. The route generation system according to claim 1 or 2, wherein the second block includes at least one point.

5. The route generation system according to claim 1 or 2, wherein the second block includes a plurality of points, each connected to four or more passages.