Base proposed site search device

Abstract

To provide a base proposed site search device that can search for an optimal proposed site for a physical distribution base, taking into account the route that would actually be used for delivery, in relation to the technique for searching for a proposed site for a physical distribution base based on the distribution of multiple delivery destinations on a map.SOLUTION: A base proposed site search device comprises a memory device storing road network data managing the road network on a map and a processing circuit. The processing circuit executes a proposed site calculation process for each of N physical distribution bases, calculating a second tentative proposed site that minimises the average distance or weighted average distance of the route to the delivery destination assigned in a first assignment, based on a first tentative proposed site and the road network data. Furthermore, the processing circuit performs an allocation calculation process that calculates a second allocation for multiple delivery destinations based on the road network data. The processing circuit then repeats the proposed site calculation process and the allocation calculation process, and when a predetermined termination condition is satisfied, the second tentative proposed site for each of the N physical distribution bases is adopted as the proposed site.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a technology for searching for candidate locations for logistics bases based on the distribution of multiple delivery destinations on a map. [Background technology]

[0002] Patent Document 1 discloses a technology for selecting candidate locations for logistics bases by determining the distance center of gravity based on the locations of multiple delivery destinations (received destinations), or by determining the volume center of gravity that also takes delivery volume into consideration.Other documents that demonstrate the technical level in this field include Patent Documents 2 and 3 below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-202352 [Patent Document 2] Japanese Patent Application Publication No. 2019-074836 [Patent Document 3] Japanese Patent Publication No. 2023-095005 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the technology disclosed in Patent Document 1, candidate locations for logistics bases are searched for based on the distance centroid or the quantity centroid. The candidate locations for logistics bases searched for in this way are locations optimized in terms of the straight-line distance from the logistics base to the delivery destination. As a result, there is a risk that the candidate locations will be locations for which the route for actual delivery is not practical.

[0005] One object of the present disclosure is to provide a technology that makes it possible to search for the most suitable candidate location for a logistics base, taking into consideration the route that will be taken when actual delivery is made. [Means for solving the problem]

[0006] One aspect of the present disclosure relates to a base candidate search device that outputs N (N is an integer greater than or equal to 1) logistics base candidate locations based on a distribution of multiple delivery destinations on a map. The base candidate search device includes one or more storage devices that store road network data that manages the road network on the map, and a processing circuit. The processing circuit initially sets a first tentative candidate location for each of the N logistics bases and a first allocation of multiple delivery destinations to the N logistics bases. The processing circuit also executes a candidate location calculation process that calculates, for each of the N logistics bases, a second tentative candidate location that minimizes the average distance or weighted average distance of the preliminary routes to the delivery destinations assigned in the first allocation, based on the first tentative candidate location and the road network data. The processing circuit also executes an allocation calculation process that calculates a second allocation of the multiple delivery destinations based on the road network data, such that each of the multiple delivery destinations is assigned to one of the N logistics bases that has the shortest post-router distance to the second tentative candidate location. The processing circuit then repeats the candidate location calculation process and the allocation calculation process, treating the second tentative candidate location for each of the N logistics bases and the second allocation of the multiple delivery destinations as the first tentative candidate location and the first allocation, respectively, and when a predetermined termination condition is met, treats the second tentative candidate location for each of the N logistics bases as a candidate location. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to search for the most suitable candidate location for a logistics base, taking into consideration the route that will be taken when actual delivery is made. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a conceptual diagram for explaining an overview of a base candidate site searching device according to an embodiment; [Figure 2] 1 is a block diagram showing a configuration of a base candidate location searching device according to an embodiment. [Figure 3] 2 is a block diagram showing a functional configuration related to a base candidate location search process executed by the base candidate location search device according to the embodiment. FIG. [Figure 4] 4 is a conceptual diagram for explaining processing in an initial setting unit shown in FIG. 3. FIG. [Figure 5]FIG. 4 is a conceptual diagram for explaining the processing in the candidate site calculation processing unit shown in FIG. 3. [Figure 6] FIG. 4 is a conceptual diagram for explaining the processing in the allocation calculation processing unit shown in FIG. 3. [Figure 7] 1 is a conceptual diagram for explaining a reference value map output by a base candidate site searching device according to an embodiment. [Figure 8] 10 is a flowchart showing a processing flow of a base candidate location search process executed by the base candidate location search device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0010] 1. Base candidate site search device FIG. 1 is a conceptual diagram for explaining an overview of a base candidate location search device 100 according to this embodiment. The base candidate location search device 100 accepts registration of a delivery destination 10 from a user. The delivery destination 10 is a location to which a package is delivered from a logistics center. The delivery destination 10 is, for example, a store that sells the delivered product. However, the type of delivery destination 10 is not particularly limited. For example, the delivery destination 10 may be a factory, warehouse, residence, etc. When the user registers the delivery destination 10, the base candidate location search device 100 acquires at least information on the location of the registered delivery destination 10 on a map. The base candidate location search device 100 may further acquire information on the amount of packages delivered to the registered delivery destination 10 per predetermined period (e.g., daily, weekly, or monthly). FIG. 1 shows the distribution of multiple registered delivery destinations 10 on a map. In FIG. 1, the reference numerals of the delivery destinations 10 are omitted except for one.

[0011] After the delivery destinations 10 are registered, the base candidate location searching device 100 receives input from the user of the specified number N (N is an integer equal to or greater than 1) of logistics bases to be placed. Then, the base candidate location searching device 100 executes a process (hereinafter referred to as "base candidate location searching process") to search for N logistics base candidate locations 20 for the distribution of the delivery destinations 10 on the registered map. The base candidate location searching device 100 outputs the processing results of the base candidate location searching process.

[0012] The candidate base site search process is a process for determining N candidate logistics base sites 20 and the allocation of multiple delivery destinations 10 to the N logistics base sites. FIG. 1 shows an example of the processing result of the candidate base site search process when the specified number N=3. That is, the processing result shown in FIG. 1 gives three candidate logistics base sites 20-A, 20-B, and 20-C and the allocation of multiple delivery destinations 10 to the three logistics base sites. In the example shown in FIG. 1, the allocation of multiple delivery destinations 10 is indicated by coloring. Specifically, the delivery destination 10 assigned to the logistics base at candidate site 20-A is delivery destination 10-A (reference numerals omitted except for one) which is colored lightly. Furthermore, the delivery destination 10 assigned to the logistics base at candidate site 20-B is delivery destination 10-B (reference numerals omitted except for one) which is colored slightly darker. The delivery destination 10 assigned to the logistics base of the candidate site 20-C is the delivery destination 10-C (reference numerals are omitted except for one) shaded in a dark color.

[0013] The user can obtain the locations of N logistics base candidate sites 20 and the allocation of multiple delivery destinations 10 to the N logistics bases from the processing results output from the base candidate site searching device 100. The user can use this information to plan the placement of logistics bases and to build a logistics system.

[0014] Conventionally, searches for candidate locations 20 for logistics bases have been performed by optimizing an objective function based on the straight-line distance from a logistics base to a delivery destination 10. However, there is a risk that the candidate locations 20 for logistics bases searched in this way will be locations for which the actual delivery route is impractical. Therefore, this embodiment proposes a candidate location search device 100 that executes a candidate location search process that can search for the optimal candidate location 20 for a logistics base by taking into account the actual delivery route.

[0015] FIG. 2 is a block diagram showing the basic configuration of a base candidate location search device 100 according to this embodiment. The base candidate location search device 100 is a computer including a processing circuit 110 and one or more storage devices 120 (hereinafter simply referred to as "storage devices 120"). The base candidate location search device 100 is connected to an input / output device 200 operated by a user. The input / output device 200 accepts various inputs from the user to the base candidate location search device 100. The input / output device 200 also presents various output information from the base candidate location search device 100 to the user by displaying or sounding it. The input / output device 200 may be, for example, a keyboard, a mouse, a touchpad, switches, a display, a speaker, a touchscreen, etc. The base candidate location search device 100 may be a server accessible via a communications network (e.g., the Internet). In this case, the input / output device 200 may be a user terminal (e.g., a personal computer, a smartphone, a tablet, etc.) connected to the base candidate location search device 100 via the communications network.

[0016] The processing circuitry 110 performs various processes. The processing circuitry 110 may be, for example, a general-purpose processor, a special-purpose processor, a central processing unit (CPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), an integrated circuit, a conventional circuit, or a combination of one or more of these. A processor including transistors and other circuits is an example of the processing circuitry 110. The processing circuitry 110 may also be referred to as circuitry or processing circuitry. Circuitry is hardware that is programmed to realize or executes the functions described in this disclosure.

[0017] The storage device 120 stores various information necessary for the processing circuit 110 to execute processing. The storage device 120 is configured with a recording medium such as a RAM (Random Access Memory), a ROM (Read Only Memory), an SSD (Solid State Drive), or an HDD (Hard Disk Drive). The storage device 120 stores a computer program 121 that can be executed by the processing circuit 110. The computer program 121 is configured with a plurality of instructions that describe the processing to be executed by the processing circuit 110. The computer program 121 may be recorded on a computer-readable recording medium. The functions of the base candidate location search device 100 are realized by cooperation between the processing circuit 110, which executes the computer program 121, and the storage device 120.

[0018] The storage device 120 further stores delivery destination information 122 and road network data D10.

[0019] The delivery destination information 122 is information relating to a plurality of delivery destinations 10 on a map registered by a user. The delivery destination information 122 includes at least information on the location of each of the plurality of delivery destinations 10. The delivery destination information 122 may also include information on the amount of cargo to be delivered to each of the plurality of delivery destinations 10 per predetermined period. The base candidate site searching device 100 acquires the delivery destination information 122 from the user via the input / output device 200.

[0020] The road network data D10 is data for managing a road network on a map. The road network data D10 is configured so that the distance of a route between any two points on the map can be obtained. The road network data D10 is generated in advance and stored in the storage device 120. The road network data D10 may be uploaded as appropriate.

[0021] The road network data D10 may include road characteristic information indicating the characteristics of each road on the map, such as the width, type (e.g., expressway, general road), frequency of congestion, frequency of road closure, speed limit, etc.

[0022] The road network data D10 may further include information on roads on the map that are unsuitable for delivery trucks to travel on (hereinafter referred to as "unsuitable roads"). Examples of unsuitable roads include roads with heavy pedestrian traffic and roads with extremely narrow widths. The base candidate site searching device 100 may be configured to acquire information on unsuitable roads from the user via the input / output device 200. In this case, the user can specify the unsuitable roads in advance.

[0023] 2. Searching for potential base locations 3 is a block diagram showing the functional configuration related to the base candidate site search process executed by the base candidate site search device 100. The base candidate site search process includes, as functional blocks, an initial setting unit P10, a candidate site calculation processing unit P20, and an allocation calculation processing unit P30. These functional blocks are realized by cooperation between the processing circuit 110 and the storage device 120. Information required for the process is stored in the storage device 120. Below, the base candidate site search process will be explained for each functional block.

[0024] 2.1 Processing in the Initialization Section The initial setting unit P10 initially sets a "tentative candidate location" for each of the N logistics bases and the allocation of multiple delivery destinations 10 to the N logistics bases. The tentative candidate locations are provisional candidate locations 20 in the base candidate location search process. As will be described later, in the base candidate location search process, the final candidate location 20 is determined by repeatedly optimizing the tentative candidate locations using the candidate location calculation processing unit P20. In addition, in the base candidate location search process, the final allocation of multiple delivery destinations 10 is determined by repeatedly updating the allocation of multiple delivery destinations 10 using the allocation calculation processing unit P30. The processing in the initial setting unit P10 is executed only once at the beginning when the base candidate location search process is executed.

[0025] 4 is a conceptual diagram for explaining the processing in the initial setting unit P10. The initial setting unit P10 acquires the distribution of multiple delivery destinations 10 from the delivery destination information 122. The initial setting unit P10 performs a clustering process on the acquired distribution of delivery destinations 10 to initially set the allocation of tentative candidate locations for each logistics base and multiple delivery destinations 10.

[0026] More specifically, the initial setting unit P10 first clusters the multiple delivery destinations 10 into N clusters through a clustering process. The clustering process method is not particularly limited. For example, the clustering process may employ k-means, Ward's method, clustering using a trained machine learning model, or the like. The initial setting unit P10 sets a temporary candidate location 21 for each of the N logistics bases within the convex hull of each of the N clusters. The position within the convex hull at which the temporary candidate location 21 is set is typically the position of the center of gravity of the convex hull. The initial setting unit P10 also sets the allocation of the multiple delivery destinations 10 so that each of the N clusters is assigned to a respective one of the N logistics bases.

[0027] In the example shown in Figure 4, the multiple delivery destinations 10 are clustered into three clusters: a cluster made up of lightly shaded delivery destinations 10-A (reference numbers omitted except for one), a cluster made up of slightly darkly shaded delivery destinations 10-B (reference numbers omitted except for one), and a cluster made up of darkly shaded delivery destinations 10-C (reference numbers omitted except for one). Three tentative candidate locations 21-A, 21-B, and 21-C are set within the convex hull (dashed dotted lines) of each of the three clusters. The three clusters also set the allocation of the multiple delivery destinations 10 to three logistics bases.

[0028] The location that is the optimal solution for the candidate location 20 for the logistics base is expected to be located within an area with a high density of delivery destinations 10. Therefore, by initially setting the tentative candidate location 21 within the convex hull of the cluster in this way, the calculation cost involved in repeatedly optimizing the tentative candidate location 21 can be reduced.

[0029] The allocation of the tentative candidate sites 21 and the plurality of delivery destinations 10 for each logistics base set by the initial setting unit P10 is transmitted to the candidate site calculation processing unit P20.

[0030] 2.2 Processing in the candidate site calculation processor The candidate location calculation processor P20 optimizes the temporary candidate locations 21 for each of the N logistics bases, taking into account the routes to the delivery destinations 10 assigned based on the road network data D10. The optimization of the temporary candidate locations 21 by the candidate location calculation processor P20 is performed based on the previously set temporary candidate locations 21. The processing by the candidate location calculation processor P20 also references the previously set allocation of the multiple delivery destinations 10. Hereinafter, the previously set temporary candidate location 21 that serves as the basis for optimization will be specifically referred to as the "first temporary candidate location 21," and the temporary candidate location 21 optimized by the candidate location calculation processor P20 will be specifically referred to as the "second temporary candidate location 21." The previously set allocation of the multiple delivery destinations 10 referenced in the processing by the candidate location calculation processor P20 will be specifically referred to as the "first allocation." In particular, when the candidate location calculation processor P20 first executes processing in the base candidate location search process, the first temporary candidate location 21 and the first allocation are the allocation of the temporary candidate locations 21 and multiple delivery destinations 10 for each logistics base that was initially set by the initial setting unit P10.

[0031] 5 is a conceptual diagram for explaining the processing in the candidate location calculation processor P20. The candidate location calculation processor P20 acquires a first tentative candidate location 21 for each of the N logistics bases and a first allocation of multiple delivery destinations 10. The candidate location calculation processor P20 also acquires the location of each of the multiple delivery destinations 10 from the delivery destination information 122. For each of the N logistics bases, the candidate location calculation processor P20 calculates, as a second tentative candidate location 21, a point that minimizes the average distance of the route 30 (hereinafter referred to as the "preliminary route 30") to the delivery destination 10 assigned in the first allocation.

[0032] More specifically, the process is as follows. A target logistics base station among the N logistics base stations for which the second tentative candidate site 21 is to be calculated is defined as the target logistics base station. Furthermore, a target delivery destination is defined as a delivery destination 10 assigned to the target logistics base station in the first allocation among the multiple delivery destinations 10. First, the candidate site calculation processor P20 calculates each preliminary route 30 from the first tentative candidate site 21 of the target logistics base station to each target delivery destination by referring to the road network data D10, and obtains the distance of each calculated preliminary route 30. Next, the candidate site calculation processor P20 calculates the average distance of the preliminary route 30 from the distance of each obtained preliminary route 30. Next, the candidate site calculation processor P20 uses the average distance of the preliminary route 30 as an objective function, and updates the temporary candidate site 21 and the preliminary route 30 in a direction that decreases the objective function based on the first tentative candidate site 21. In other words, the candidate site calculation processor P20 optimizes the temporary candidate site 21 using the average distance of the preliminary route 30 as the objective function. To reduce computational costs, it is preferable that the optimization of the temporary candidate site 21 be performed within the convex hull of the set of target delivery destinations. Then, the candidate site calculation processing unit P20 sets the tentative candidate site 21 when the objective function is minimized as the second tentative candidate site 21. At this time, each preliminary route 30 from the second tentative candidate site 21 of the target logistics base to each target delivery destination is calculated.

[0033] 5, for three logistics bases, three tentative candidate locations 21-A, 21-B, and 21-C as first tentative candidate locations 21 are optimized to three tentative candidate locations 21-A, 21-B, and 21-C as second tentative candidate locations 21. Furthermore, preliminary routes 30-A, 30-B, and 30-C corresponding to the three tentative candidate locations 21-A, 21-B, and 21-C are calculated for the first tentative candidate location 21 and the second tentative candidate location 21, respectively. The preliminary routes 30-A, 30-B, and 30-C calculated for the second tentative candidate location 21 are routes that have the shortest average distance from the tentative candidate location 21 to the delivery destination 10 in the first allocation.

[0034] The candidate site calculation processor P20 may be configured to optimize the tentative candidate site 21 using the "weighted average distance" of the preliminary routes 30 as the objective function instead of the average distance of the preliminary routes 30. In this case, the candidate site calculation processor P20 assigns a weight to each preliminary route 30. The candidate site calculation processor P20 then calculates the weighted average distance of the preliminary routes 30 from the weight assigned to each preliminary route 30 and the distance of each preliminary route 30. The candidate site calculation processor P20 can assign a weight to each preliminary route 30 by adopting, for example, the following perspectives:

[0035] One viewpoint is to assign a weight to the preliminary route 30 corresponding to the delivery destination 10 based on the amount of cargo delivered to that delivery destination 10 per predetermined period. From this viewpoint, the greater the amount of cargo, the greater the weight of the preliminary route 30. According to this viewpoint, the temporary candidate locations 21 are optimized so that the distance of the preliminary route 30 to a delivery destination 10 with a large amount of cargo becomes shorter. The candidate location calculation processing unit P20 may be configured to acquire information on the amount of cargo delivered to each delivery destination 10 per predetermined period from the delivery destination information 122.

[0036] Another viewpoint is to assign a weight to the preliminary route 30 based on the characteristics of the roads on the preliminary route 30. The characteristics of the roads may affect the delivery of packages. For example, in this viewpoint, the narrower the road width, the greater the weight of the preliminary route 30. For example, if the road type is a motorway, the weight of the preliminary route 30 is reduced compared to when the road type is a general road. For example, the higher the frequency of congestion or road closures on the road, the greater the weight of the preliminary route 30. For example, the lower the speed limit, the greater the weight of the preliminary route 30. According to this viewpoint, the temporary candidate site 21 is optimized so as to shorten the distance of the preliminary route 30, which has a large impact on the delivery of packages. The candidate site calculation processing unit P20 may be configured to acquire road characteristic information indicating the characteristics of each road on the map from the road network data D10.

[0037] The candidate site calculation processing unit P20 may further be configured to optimize the tentative candidate site 21 so that unsuitable roads are not included in the preliminary route 30, and calculate a second tentative candidate site 21. In other words, the candidate site calculation processing unit P20 is configured to calculate the preliminary route 30 for roads excluding unsuitable roads. This makes it possible to calculate a second tentative candidate site 21 that is optimized for the preliminary route 30 that does not include unsuitable roads. At the same time, it is possible to prevent unsuitable roads from being included in the preliminary route 30 calculated for the second tentative candidate site 21. It is also possible to reduce the calculation cost involved in calculating the preliminary route 30. The candidate site calculation processing unit P20 may be configured to acquire information on unsuitable roads from the road network data D10.

[0038] The candidate site calculation processing unit P20 may further be configured to calculate the second tentative candidate site 21 by taking into account an exclusion zone that specifies points on the map that are not to be selected as candidate sites 20 for logistics bases. That is, the candidate site calculation processing unit P20 calculates the second tentative candidate site 21 by optimizing the tentative candidate site 21 by excluding points included in the exclusion zone. For example, the exclusion zone may be a point that is not suitable for land acquisition (e.g., a point where the placement of a logistics base is prohibited in a land use designated by a local government, etc.). The exclusion zone may also be a point specified by the user. For example, the exclusion zone may be specified by one or more polygons on the map. By calculating the second tentative candidate site 21 by taking the exclusion zone into account in this way, the optimization of the tentative candidate site 21 can be made more efficient and calculation costs can be reduced. The base candidate site search device 100 may be configured to store data for managing the exclusion zone in the storage device 120. In particular, the base candidate site search device 100 may be configured to receive an input specifying the exclusion zone from the user via the input / output device 200. The candidate site calculation processor P20 may be configured to acquire information on the excluded area from the data stored in the storage device 120.

[0039] The second tentative candidate sites 21 for each logistics base calculated by the candidate site calculation processor P20 are transmitted to the allocation calculation processor P30.

[0040] 2.3 Processing in the allocation calculation processing unit The allocation calculation processing unit P30 calculates the allocation of multiple delivery destinations 10 to the second tentative candidate sites 21 of each logistics base based on the road network data D10. Hereinafter, the allocation of multiple delivery destinations 10 calculated by the allocation calculation processing unit P30 will be specifically referred to as the "second allocation."

[0041] 6 is a conceptual diagram for explaining the processing in the allocation calculation processing unit P30. The allocation calculation processing unit P30 acquires the second tentative candidate site 21 for each logistics base calculated by the candidate site calculation processing unit P20. The allocation calculation processing unit P30 also acquires the location of each of the multiple delivery destinations 10 from the delivery destination information 122. The allocation calculation processing unit P30 calculates the second allocation by assigning each of the multiple delivery destinations 10 to the logistics base out of the N logistics bases whose route 31 (hereinafter referred to as the "post route 31") to the second tentative candidate site 21 is the shortest.

[0042] More specifically, the process is as follows. Consider the allocation of one delivery destination 10 among multiple delivery destinations 10. The allocation calculation processing unit P30 refers to the road network data D10, calculates a post-routes 31 for the delivery destination 10 for each of N logistics bases, and obtains the distance of the calculated post-routes 31. The allocation calculation processing unit P30 then allocates the delivery destination 10 to the logistics base for which the distance of the obtained post-routes 31 is the shortest. The allocation calculation processing unit P30 calculates a second allocation of the multiple delivery destinations 10 by performing the above process for each of the multiple delivery destinations 10. At this time, a post-routes 31 from the second tentative candidate site 21 to each delivery destination 10 is calculated for each of the N logistics bases.

[0043] The example shown in FIG. 6 illustrates the calculation results of the second allocation of multiple delivery destinations 10 by the allocation calculation processor P30 for three logistics centers. In particular, subsequent routes 31-A, 31-B, and 31-C corresponding to three tentative candidate locations 21-A, 21-B, and 21-C are calculated. The example shown in FIG. 6 shows that the second allocation calculated by the allocation calculation processor P30 has updated the allocation of some delivery destinations 10 compared to the first allocation. For example, some of the delivery destinations 10 that were assigned to the logistics center of temporary candidate location 21-A in the first allocation are now assigned to the logistics center of temporary candidate location 21-B in the second allocation. Furthermore, for example, some of the delivery destinations 10 that were assigned to the logistics center of temporary candidate location 21-C in the first allocation are now assigned to the logistics center of temporary candidate location 21-A in the second allocation.

[0044] However, there are some delivery destinations 10 for which the allocation is not updated between the first allocation and the second allocation. For such delivery destinations 10, the preliminary route 30 and the posterior route 31 usually coincide. Therefore, in order to reduce the calculation cost involved in calculating the posterior route 31, the allocation calculation processing unit P30 may be configured to further acquire the first allocations of the multiple delivery destinations 10 and the preliminary route 30 calculated for the second tentative candidate site 21 by the candidate site calculation processing unit P20.

[0045] The allocation calculation processing unit P30 may further be configured to calculate the second allocation so that unsuitable roads are not included in the post-event route 31. In other words, the allocation calculation processing unit P30 is configured to calculate the post-event route 31 for roads excluding unsuitable roads. This makes it possible to prevent unsuitable roads from being included in the calculated post-event route 31. It is also possible to reduce the calculation cost involved in calculating the post-event route 31. The allocation calculation processing unit P30 may be configured to acquire information on unsuitable roads from the road network data D10.

[0046] The second allocation of the plurality of delivery destinations 10 calculated by the allocation calculation processing unit P30 is transmitted to the candidate location calculation processing unit P20.

[0047] 2.4 Output of processing results In the base candidate site search process, after the allocation calculation processing unit P30 calculates the second allocation of multiple delivery destinations 10, it is determined whether a predetermined termination condition is met. In the base candidate site search process, the processing by the candidate site calculation processing unit P20 and the processing by the allocation calculation processing unit P30 are repeatedly executed until the predetermined termination condition is met. Examples of the predetermined termination condition include the second allocation calculated by the allocation calculation processing unit P30 being the same as the first allocation, the amount of change (straight-line distance) between the second temporary candidate site 21 and the first temporary candidate site 21 calculated by the candidate site calculation processing unit P20 being less than a threshold, and the process being repeated a predetermined number of times.

[0048] When the process is repeated, that is, when a predetermined termination condition is not satisfied, the second tentative candidate sites 21 for each of the N logistics bases and the second allocation of the multiple delivery destinations 10 calculated in the previous process are set as the first tentative candidate sites and the first allocation in the current process, respectively. Then, in the base candidate site search process, optimization of the tentative candidate sites 21 (calculation of the second tentative candidate sites 21) by the candidate site calculation processing unit P20 and calculation of the second allocation by the allocation calculation processing unit P30 are repeated.

[0049] When a predetermined termination condition is satisfied, the second temporary candidate site 21 calculated by the candidate site calculation processing unit P20 and the second allocation calculated by the allocation calculation processing unit P30 each become the processing results of the base candidate site search process. In other words, when the predetermined termination condition is satisfied, the second temporary candidate site 21 for each of the N logistics bases becomes the final candidate site 20. Furthermore, when the predetermined termination condition is satisfied, the second allocation of the multiple delivery destinations 10 becomes the final allocation of the multiple delivery destinations 10. The processing result may further include a posterior route 31 calculated by the allocation calculation processing unit P30. The base candidate site search device 100 outputs the processing result of the base candidate site search process via the input / output device 200.

[0050] As described above, according to this embodiment, the road network data D10 is referenced to calculate the second tentative candidate location 21 that minimizes the average distance or weighted average distance of the preliminary route 30 to the delivery destination 10 assigned in the first allocation for each of the N logistics bases. Furthermore, the road network data D10 is referenced to calculate the second allocation of the multiple delivery destinations 10 so that each of the multiple delivery destinations 10 is assigned to the logistics base among the N logistics bases that minimizes the distance of the subsequent route 31 to the second tentative candidate location 21. Furthermore, the calculation of the second tentative candidate location and the second allocation is repeated until a predetermined termination condition is met. Then, the second tentative candidate location 21 that satisfies the predetermined termination condition is output as the candidate location 20 for the logistics base. Thus, according to this embodiment, it is possible to search for the optimal candidate location 20 for the logistics base, taking into account the route when actual delivery is performed.

[0051] 2.5 Reference value map output It is conceivable that the user will not adopt the logistics base candidate site 20 obtained by the base candidate site search process as the location of the logistics base for various reasons, such as the difficulty of purchasing land. Therefore, when a predetermined termination condition is satisfied, the base candidate site search device 100 may be further configured to output a "reference value map" that allows the user to consider the location of a logistics base, including locations other than the candidate site 20, for a target logistics base among the N logistics bases. Here, the target logistics base may be a logistics base specified by the user from among the N logistics bases via the input / output device 200.

[0052] FIG. 7(A) is a conceptual diagram illustrating a reference value map output by the base candidate search device 100. FIG. 7(A) illustrates a case where the logistics base of candidate site 20-C is set as the target logistics base. When outputting the reference value map, the base candidate search device 100 sets multiple sub-candidate sites 22 within the convex hull (dashed line) of the set of delivery destinations 10 assigned to the target logistics base. For example, the base candidate search device 100 sets the sub-candidate sites 22 at regular intervals with candidate site 20 as the base point. The number of sub-candidate sites 22 to be set may be specified by the user via the input / output device 200. The reference value map is a map that indicates a "reference value" for each of the multiple sub-candidate sites 22. The reference value is a value that indicates the magnitude of the average distance or weighted average distance of the route from the sub-candidate site 22 to the delivery destination 10 assigned to the target logistics base. The base candidate search device 100 calculates the reference value for each of the multiple sub-candidate sites 22 based on the road network data D10. More specifically, the base candidate site searching device 100 refers to the road network data D10, calculates each route from the sub-candidate site 22 to each delivery destination 10, and acquires the distance of each calculated route. Then, the base candidate site searching device 100 calculates a reference value from the acquired distance of each route.

[0053] In the example shown in FIG. 7(A), the magnitude of the reference value is indicated by the darkness of the color on the reference value map. In other words, the darker the color, the smaller the magnitude of the reference value of the sub-candidate site 22. By checking the reference value map, the user can consider the placement of a logistics base for each of the sub-candidate sites 22 in addition to the candidate site 20. Typically, the user may consider the placement of logistics bases in the order of the sub-candidate sites 22 with the smallest reference value.

[0054] The base candidate site searching device 100 may be configured to set all points within the convex hull of the set of delivery destinations 10 assigned to the target logistics base as sub-candidate sites 22, and calculate the reference value for each point. In this case, the reference value map can be represented as a heat map that visualizes the magnitude of the reference value. FIG. 7(B) is a diagram showing an example of a reference value map represented as a heat map. In the example shown in FIG. 7(B), the reference value map is represented as a heat map in which the darker the color, the smaller the reference value.

[0055] 3 Processing flow Fig. 8 is a flowchart showing the processing flow of the base candidate site search processing executed by the base candidate site search device 100. Each step in the processing flow shown in Fig. 8 is executed by the processing circuit 110 of the base candidate site search device 100. The processing flow shown in Fig. 8 starts, for example, when a user requests execution of a process via the input / output device 200.

[0056] In step S100, the processing circuit 110 acquires various information necessary for executing the process, such as delivery destination information 122 and road network data D10.

[0057] Next, in step S200, the processing circuit 110 initially sets a first tentative candidate site 21 for each of the N logistics bases and a first allocation of multiple delivery destinations to the N logistics bases.

[0058] Next, in step S300, the processing circuit 110 executes processing (candidate site calculation processing) related to the candidate site calculation processor P20. That is, the processing circuit 110 calculates, for each of the N logistics bases, a second tentative candidate site 21 that minimizes the average distance or weighted average distance of the preliminary route 30 to the delivery destination 10 assigned in the first allocation.

[0059] Next, in step S400, the processing circuit 110 executes processing (allocation calculation processing) related to the allocation calculation processing unit P30. That is, the processing circuit 110 calculates a second allocation of the multiple delivery destinations 10 so as to allocate each of the multiple delivery destinations 10 to the logistics base among the N logistics bases whose distance of the subsequent route 31 to the second tentative candidate site 21 is the shortest.

[0060] Next, in step S500, processing circuit 110 determines whether a predetermined termination condition is met. If the predetermined termination condition is not met (step S500; No), processing circuit 110 sets the calculated second tentative candidate site 21 and second allocation as the first tentative candidate site 21 and first allocation, respectively, and repeats the processing of step S300 again. If the predetermined termination condition is met (step S500; Yes), processing circuit 110 outputs a processing result in which the calculated second tentative candidate site 21 is set as the candidate site 20 (step S600). After step S600, the processing ends. [Explanation of symbols]

[0061] 10. Delivery Address 20 candidate sites 21 Tentative candidate site 22 Sub-candidate sites 30 Advance Route 31 Post-event route 100 Base candidate site search device 110 Processing circuit 120 Storage device 121 Computer Programs 200 I / O devices

Claims

1. A base candidate site searching device that outputs N (N is an integer equal to or greater than 1) logistics base candidate sites for a distribution of multiple delivery destinations on a map, one or more storage devices that store road network data for managing a road network on a map; a processing circuit; Equipped with The processing circuitry Initializing a first tentative candidate location for each of the N logistics bases and a first allocation of the plurality of delivery destinations to the N logistics bases; execute a candidate site calculation process for calculating, for each of the N logistics bases, a second tentative candidate site that minimizes an average distance or a weighted average distance of a preliminary route to a delivery destination assigned in the first assignment based on the first tentative candidate site and the road network data; execute an allocation calculation process to calculate a second allocation of the plurality of delivery destinations based on the road network data so as to allocate each of the plurality of delivery destinations to a logistics center among the N logistics centers that has the shortest subsequent route distance to the second tentative candidate location; repeating the candidate site calculation process and the allocation calculation process with the second tentative candidate site and the second allocation of the plurality of delivery destinations for each of the N logistics bases as the first tentative candidate site and the first allocation, respectively; When a predetermined termination condition is satisfied, the second tentative candidate site of each of the N logistics bases is set as the candidate site. It is configured as follows: Potential base location search device.

2. The base candidate site searching device according to claim 1, In the initial setting, the processing circuitry: Clustering the plurality of delivery destinations into N clusters; setting the first tentative candidate site of each of the N logistics bases within a convex hull of each of the N clusters; The first allocation of the plurality of delivery destinations is set so that each of the N clusters is allocated to each of the N logistics bases. Potential base location search device.

3. The base candidate site searching device according to claim 1, When the termination condition is satisfied, the processing circuitry further In the second allocation, a plurality of sub-candidate locations are set within a convex hull of a set of delivery destinations allocated to a target logistics base among the N logistics bases; Based on the road network data, a reference value indicating the magnitude of the average distance or weighted average distance of the route to the delivery destination assigned to the target logistics base is calculated for each of the plurality of sub-candidate sites; Outputting a map showing the reference values ​​calculated for each of the plurality of sub-candidate sites Potential base location search device.

4. The base candidate site searching device according to claim 1, The road network data includes information on unsuitable roads that are unsuitable for delivery vehicles to travel on, In the candidate site calculation process, the processing circuit calculates the second tentative candidate site so that the unsuitable road is not included in the preliminary route; In the allocation calculation process, the processing circuit calculates the second allocation so that the unsuitable road is not included in the subsequent route. Potential base location search device.

5. The base candidate site searching device according to claim 1, the one or more storage devices further store data for managing excluded areas that designate points on the map that are not to be the candidate sites; In the candidate site calculation process, the processing circuit calculates the second tentative candidate site excluding points included in the excluded area. Potential base location search device.

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