Delivery support device, delivery support method, and delivery support program

Abstract

A delivery assistance device (10) comprises a derivation unit (24) that derives a route for a resource delivered by a delivery apparatus, to minimize the maximum value of a time in which the resource is depleted at a plurality of first points (5). The derivation unit derives the route in accordance with a branch and bound method which uses a relaxation problem for integrating, into one point, a plurality of second points which are among the plurality of first points and for which a sequence of delivery is yet to be confirmed.

Description

[Technical field]

[0001] The embodiments relate to a delivery assistance device, a delivery assistance method, and a delivery assistance program. [Background technology]

[0002] Delivery vehicles are one of the primary means of delivering resources to their destinations.

[0003] In order to efficiently deliver resources to multiple destinations, the problem of determining the appropriate route for delivery vehicles is of great interest. For example, in the event of a large-scale disaster, it is necessary to select a route that minimizes the time that resources such as electricity and water are depleted at the destinations.

[0004] A branch-and-bound method is known as a method for selecting the above-mentioned route. The branch-and-bound method is a technique that is often used to find an exact solution to the vehicle routing problem (VRP).

[0005] For example, in Non-Patent Document 1, the maximum time that resources are depleted at multiple delivery destinations (maximum depletion time) is set as an objective function. Then, an optimization problem for minimizing the objective function is solved by a branch-and-bound method. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] M. Ogawa et al. “A route searching method using two-dimensional coordinates,” IEICE, DOI:10.34385 / proc.63.E4-3, 2020. Summary of the Invention [Problem to be solved by the invention]

[0007] However, Non-Patent Document 1 raises the following concerns regarding the relaxation problem used in the bounding operation of the branch and bound method.

[0008] First, because the travel time between points is proportional to the Euclidean distance, the travel time on the map cannot be used, which means that the time when resources are depleted may differ from reality.

[0009] In addition, since it is impossible to determine whether a relaxed problem is NP-hard or not, there is no guarantee that an optimal solution can be obtained. Therefore, the solution finally obtained by the branch-and-bound method may not be an exact solution.

[0010] In addition, the amount of time that the delivery van will stay at the delivery destination is not taken into consideration, which makes it difficult to deal with cases where the amount of time that the delivery van will stay at each delivery destination varies.

[0011] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a means for efficiently determining an optimal delivery route for resources. [Means for solving the problem]

[0012] A delivery support device according to one embodiment includes a derivation unit that derives a route for a resource by a delivery device in order to minimize a maximum time for the resource to be depleted at a plurality of first points. The derivation unit derives the route based on a branch-and-bound method using a relaxation problem of consolidating a plurality of second points, the delivery order of which is not yet determined, among the plurality of first points into one point. Each of the first locations is associated with a depletion time of the resource and a stay time of the delivery device. The derivation unit includes a first route selection unit that selects a first route for delivering the resource to the second locations based on the depletion time and the sum of the stay time, a first calculation unit that calculates a lower limit of the maximum value based on the first route, a second route selection unit that selects a second route for delivering the resource to the first locations based on the depletion time, and a second calculation unit that calculates an upper limit of the maximum value based on the second route. Effect of the Invention

[0013] According to the embodiment, it is possible to provide a means for efficiently determining an optimal delivery route for resources. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of the configuration of a delivery system according to an embodiment. [Diagram 2]FIG. 2 is a block diagram illustrating an example of a hardware configuration of the delivery support device according to the embodiment. [Diagram 3] FIG. 3 is a block diagram illustrating an example of a functional configuration of the delivery support device according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of delivery van information according to the embodiment. [Diagram 5] FIG. 5 is a diagram illustrating an example of the configuration of delivery destination information according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of a configuration of travel time information according to the embodiment. [Figure 7] FIG. 7 is a flowchart illustrating an example of the delivery support operation in the delivery support device according to the embodiment. [Figure 8] FIG. 8 is a diagram showing the grace period and the residence time in a specific example. [Figure 9] FIG. 9 is a diagram showing travel times in a specific example. [Figure 10] FIG. 10 is a diagram showing idle times in a specific example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments will be described with reference to the drawings. In the following description, components having the same function and configuration are given the same reference symbol. In addition, when multiple components having the same reference symbol are to be distinguished from each other, they are distinguished from each other by an additional reference symbol (e.g., a hyphen and a number such as "-1") that is added following the common reference symbol.

[0016] 1. Configuration The configuration of the delivery system according to the embodiment will be described.

[0017] 1.1 Overall structure First, a configuration of a delivery system according to an embodiment will be described. Fig. 1 is a block diagram showing an example of the configuration of a delivery system according to an embodiment.

[0018] As shown in Fig. 1, the delivery system 1 is a system for supplying resources within a certain area using a delivery vehicle 4. The delivery system 1 includes a delivery support center 2, a delivery base 3, and multiple delivery destinations 5-1, 5-2, 5-3, 5-4, 5-5, and 5-6. In the following, when there is no particular distinction between the multiple delivery destinations 5-1 to 5-6, they may be referred to as "delivery destinations 5."

[0019] The delivery support center 2 generates a delivery plan for comprehensively controlling the delivery of resources in the delivery system 1. The delivery support center 2 is configured to be wirelessly connected to the delivery base 3. As a result, the delivery support center 2 wirelessly transmits the generated optimal delivery route to the delivery base 3.

[0020] The delivery support center 2 also includes a delivery support device 10. The delivery support device 10 is a computer that supports the generation of an optimal delivery route in the delivery support center 2. Details regarding the delivery support device 10 will be described later.

[0021] The delivery base 3 is, for example, a place where resources are stored. At least one delivery vehicle 4 is placed at the delivery base 3. The delivery base 3 instructs the delivery vehicle 4 to deliver the resources based on the optimal route received from the delivery support center 2.

[0022] The delivery van 4 is a device such as a vehicle capable of delivering resources. The delivery van 4 delivers the resources to the delivery destination 5 along the optimal route received from the delivery support center 2. The objective of the delivery van 4 is, for example, to find the maximum time (maximum depletion time T max The objective of the delivery vehicle 4 is to minimize the optimal route transmitted from the delivery support center 2.

[0023] The delivery destination 5 is a location to which resources are delivered by the delivery truck 4. The delivery destination 5 is, for example, an evacuation site in the event of a disaster. Resources are, for example, infrastructure resources such as water and electricity. Resources are stockpiled in advance at the delivery destination 5. In the event of a disaster, the resources stockpiled at the delivery destination 5 are gradually consumed by evacuees.

[0024] In the following, the locations of the delivery vehicle 4 and the delivery destination 5 on the map (i.e., on a two-dimensional plane) are associated with a vertex v. In the example of FIG. 1, the delivery vehicle 4 is associated with the vertex v. 0 Each of the multiple delivery destinations 5-1 to 5-6 corresponds to a vertex v 1 ~v 6 It corresponds to.

[0025] 1.2 Delivery support equipment Next, the configuration of the delivery support device according to the embodiment will be described.

[0026] 1.2.1 Hardware Configuration 2 is a block diagram showing an example of a hardware configuration of a delivery support device according to an embodiment. As shown in FIG. 2, the delivery support device 10 includes a control circuit 11, a memory 12, a communication module 13, a user interface 14, and a drive 15.

[0027] The control circuit 11 is a circuit that performs overall control of each component of the delivery support device 10. The control circuit 11 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory).

[0028] The memory 12 is an auxiliary storage device of the delivery support device 10. The memory 12 includes, for example, a hard disk drive (HDD), a solid state drive (SSD), a memory card, etc. The memory 12 stores various information used in the delivery support operation and a delivery support program. The delivery support management program can be stored in the memory 12 by being transmitted from outside the delivery support device 10 via a network (not shown).

[0029] The delivery support operation is a series of operations executed to support the generation of a delivery plan for resources in the delivery system 1. The delivery support operation is, for example, a sequence of operations that can be executed to support the generation of a delivery plan for resources in the delivery system 1. max The delivery assistance program is a program for causing the delivery assistance device 10 to execute the delivery assistance operation. The delivery assistance operation will be described in detail later.

[0030] The communications module 13 is circuitry used to send and receive data over a network.

[0031] The user interface 14 is a circuit for communicating information between a user and the control circuit 11. The user interface 14 includes input devices and output devices. The input devices include, for example, a touch panel and an operation button. The output devices include, for example, an LCD (Liquid Crystal Display) and an EL (Electroluminescence) display, and a printer. The user interface 14 converts input from the user (user input) into an electrical signal and then transmits it to the control circuit 11. The user interface 14 outputs the execution result of the delivery assistance program received from the control circuit 11 to the user.

[0032] The drive 15 is a device for reading a program stored in a storage medium 16. The drive 15 includes, for example, a CD (Compact Disk) drive and a DVD (Digital Versatile Disk) drive.

[0033] The storage medium 16 is a medium that stores information such as a program by electrical, magnetic, optical, mechanical, or chemical action. The storage medium 16 may store a delivery assistance program.

[0034] 1.2.2 Functional Configuration FIG. 3 is a block diagram illustrating an example of a functional configuration of the delivery support device according to the embodiment.

[0035] The CPU of the control circuit 11 loads the delivery support program stored in the memory 12 or the storage medium 16 into the RAM. The CPU of the control circuit 11 then interprets and executes the delivery support program loaded into the RAM to control the memory 12, the communication module 13, the user interface 14, the drive 15, and the storage medium 16. As a result, as shown in Fig. 3, the delivery support device 10 functions as a computer equipped with an input unit 21, a storage unit 22, a route management unit 23, an optimal route derivation unit 24, and an output unit 25.

[0036] Based on the input from the user, the input unit 21 stores various information in the storage unit 22. The various information stored in the storage unit 22 includes, for example, delivery vehicle information 22a, delivery destination information 22b, and travel time information 22c.

[0037] 4 to 6 are conceptual diagrams showing examples of the configuration of delivery van information, delivery destination information, and movement range information according to the embodiment, respectively.

[0038] 4, the delivery vehicle information 22a is information related to the delivery vehicle 4. Specifically, the delivery vehicle information 22a includes information on the delivery vehicle vertices and positions.

[0039] The vehicle vertex uniquely identifies the vertex name associated with vehicle 4.

[0040] The delivery van position is the current position information of the delivery van 4. The delivery van position is expressed, for example, in two-dimensional coordinates (X, Y). The delivery van position may also be expressed in latitude and longitude.

[0041] In the example of FIG. 4, the delivery support device 10 determines whether the vertex v 0 The delivery vehicle 4, which is associated with the delivery vehicle position (x 0 ,y 0 ) you can know that you are in

[0042] 5, the delivery destination information 22b is information on the delivery destination 5 waiting for delivery of resources. Specifically, the delivery destination information 22b includes information on the delivery destination vertex, the delivery destination position, the grace period, and the residence time.

[0043] The destination vertex uniquely identifies the vertex name associated with the destination 5 .

[0044] The delivery destination position is position information of the delivery destination 5. The delivery destination position is expressed, for example, by two-dimensional coordinates (x, y). The delivery destination position may be expressed by latitude and longitude, similar to the delivery vehicle position.

[0045] The grace period d is information indicating the time from a reference time until the resource stockpiled at the delivery destination 5 is depleted. The reference time is fixed, for example, to the start time of the delivery support operation. Accordingly, the grace period d is fixed while the delivery support operation is being performed. The grace period d may be replaced with the time when the resource is depleted.

[0046] The sojourn time p is information indicating the time from when the delivery vehicle 4 starts to finish supplying resources after arriving at the delivery destination 5. During the sojourn time p, the delivery vehicle 4 does not move from the delivery destination 5. After the sojourn time p has elapsed since the delivery vehicle 4 arrived at the delivery destination 5, the delivery vehicle 4 departs for the next delivery destination 5.

[0047] In the example of FIG. 5, the delivery support device 10 selects the vertex v i The delivery destination 5-i associated with i ,y i ) that the delivery support device 10 is in the middle of the delivery destination 5-i. i and the residence time from the arrival of the delivery vehicle 4 to the completion of the supply of resources is p i (i is an arbitrary integer between 1 and 6). In this way, the grace period d and the residence time p are applied to each delivery destination 5 in a mutually independent value.

[0048] As shown in FIG. 6, the travel time information 22c is information indicating a travel time t. The travel time t is the time required to travel between a delivery vehicle 4 and an arbitrary delivery destination 5, and between any two delivery destinations 5 (hereinafter referred to as "between vertices"). The travel time t is not necessarily proportional to the Euclidean distance between vertices. The travel time t can be determined, for example, taking into consideration information such as roads connecting the vertices. In other words, the travel time t corresponds to the time required to actually travel along the roads depicted on the map.

[0049] In the example of FIG. 6, the delivery support device 10 determines whether the vertex v i and vertex v j The travel time t between i ,v j ) (j is an integer between 0 and 6, inclusive, and different from i).

[0050] Returning to FIG. 3, the functional configuration of the delivery support device 10 will be described.

[0051] The route management unit 23 is a functional block for managing routes that the delivery vehicle 4 can take when delivering resources to the delivery destinations 5. Each route is a delivery order that is defined under the constraint that, for example, starting from the current position of the delivery vehicle 4, the delivery vehicle 4 passes through each of the delivery destinations 5 to which the resources should be delivered once. The route management unit 23 generates a route list L based on the delivery vehicle information 22a and the delivery destination information 22b. The route list L is a collection of routes.

[0052] In response to a request from the optimal route derivation unit 24, the route management unit 23 extracts a route group P from the route list L. The route group P is a subset of routes in the route list L. Specifically, for example, the route group P includes at least one route that has a common delivery destination 5 to be delivered first among the delivery destinations 5 for which the delivery order has not been determined in the route list L. The route management unit 23 transmits the extracted route group P to the optimal route derivation unit 24. Then, the route management unit 23 deletes the route group P transmitted to the optimal route derivation unit 24 from the route list L.

[0053] The route management unit 23 adds the sub-route group P' generated by the branching process by the optimal route derivation unit 24 to the route list L as a new route group P. The sub-route group P' is a subset of routes in a certain route group P. Specifically, for example, the sub-route group P' includes at least one route that has a common delivery destination 5 to be delivered first among the delivery destinations 5 in a certain route group P whose delivery order has not been determined. The branching process will be described later.

[0054] The optimal route derivation unit 24 is a functional block for deriving an optimal route from the route list L by a branch and bound method. max The optimal route derivation unit 24 includes an upper limit route selection unit 30, an upper limit calculation unit 31, a first judgment unit 32, an update unit 33, a relaxed problem setting unit 34, an idle time calculation unit 35, a lower limit route selection unit 36, a lower limit calculation unit 37, a second judgment unit 38, and a branching unit 39.

[0055] The upper limit path selection unit 30 selects the upper limit path r from the path group P. 1 This is a function block for selecting the upper limit route r 1 is the maximum exhaustion time T max The upper limit value UB may be read as an upper bound. Specifically, for example, the upper limit value route selection unit 30 selects routes for destinations 5 whose delivery order has not been determined in the route group P in order from the destination 5 with the shortest grace time d as the upper limit value route r. 1 The upper limit path selection unit 30 selects the selected upper limit path r 1 to the upper limit calculation unit 31.

[0056] In addition, the upper limit route r 1 In the above, if the resource is delivered to the delivery destination 5-i in the order of k, the relationship between i and k is expressed as the following formula (1). However, if k=0, then i=0.

[0057]

number

[0058] The upper limit calculation unit 31 calculates the upper limit path r 1 Specifically, for example, the upper limit calculation unit 31 calculates the upper limit path r 1 The time when delivery vehicle 4 arrives at destination 5-i is a i (r 1 ) is calculated, where p 0 =0.

[0059]

number

[0060] Then, the upper limit calculation unit 31 calculates the arrival time a at the delivery destination 5-i according to the following formula (3): i (r 1 ) based on the upper limit route r 1 The depletion time T i (r 1 ) is calculated.

[0061]

number

[0062] Depletion time T i (r 1 ) is the maximum value of the upper limit route r 1 Maximum depletion time T max That is, the upper limit calculation unit 31 calculates the upper limit value UB according to the following equation (4). The upper limit calculation unit 31 transmits the calculated upper limit value UB to the first determination unit 32.

[0063]

number

[0064] The first judgment unit 32 is a functional block for judging whether or not to update the evaluation function in the branch and bound method. The first judgment unit 32 judges whether or not the upper limit value UB is greater than the evaluation function. If the upper limit value UB is greater than the evaluation function, the first judgment unit 32 transmits the upper limit value UB to the update unit 33. If the upper limit value UB is equal to or less than the evaluation function, the first judgment unit 32 does not transmit the upper limit value UB to the update unit 33.

[0065] The update unit 33 is a functional block for updating the evaluation function. When the upper limit value UB is received from the first judgment unit 32, the update unit 33 updates the evaluation function with the upper limit value UB. The update unit 33 also updates the updated evaluation function and the upper limit path r corresponding to the evaluation function. 1 are stored in the memory 12 in association with each other.

[0066] The relaxed problem setting unit 34 is a functional block for setting a relaxed problem. A relaxed problem is a problem in which the difficulty of deriving a solution is relaxed by imposing constraints on the original problem (i.e., the problem of deriving an optimal route that minimizes the maximum depletion time among routes for delivering resources to all delivery destinations 5 on a map). The relaxed problem is a problem in which the difficulty of deriving a solution is relaxed by imposing constraints on the original problem (i.e., the problem of deriving an optimal route that minimizes the maximum depletion time T max This is applied when calculating the lower limit LB of the route group P. The lower limit may be interpreted as a lower bound. Specifically, the relaxation problem setting unit 34 imposes a constraint to aggregate all delivery destinations 5 whose delivery order has not been determined in the route group P to an appropriate position. The appropriate position is, for example, the position of the delivery destination 5 whose delivery order is the last among the delivery destinations 5 whose delivery order has been determined in the route group P. By imposing such a constraint, the travel time t between the delivery destinations 5 whose positions have been aggregated can be considered to be 0.

[0067] In the following explanation, the vertex corresponding to the destination 5-i whose location is aggregated in the relaxation problem is called vertex v' i Let vertex v' i The grace time and residence time in the relaxation problem for destination 5-i corresponding to i and p' i Also, vertex v' iThe arrival time and the depletion time in the relaxation problem for destination 5-i corresponding to i and T' i Then, the exhaustion time T' i The maximum depletion time based on T' max Let us assume that.

[0068] Note that for all vertices v' i The positions of the two are the same. i and stay time p' i is the grace period d i and stay time p i (d' i =d i , p' i =p i ).

[0069] The idle time calculation unit 35 is a functional block for calculating the idle time It applied to the relaxed problem. For example, in the relaxed problem, the idle time It is defined as the time during which the delivery vehicle 4 is unable to supply resources after finishing supplying resources to a certain delivery destination 5 and before starting to supply resources to the next delivery destination 5. The idle time It is calculated according to the travel time t in the original problem. Specifically, for example, i After completing the supply of resources to destination 5 corresponding to vertex v' j The idle time Itj until the supply of resources to the corresponding delivery destination 5 is started is expressed as in the following formula (5).

[0070]

number

[0071] The idle time calculation unit 35 calculates the idle time It according to the formula (5). The idle time calculation unit 35 transmits the calculated idle time It to the lower limit path selection unit 36.

[0072] The lower limit path selection unit 36 ​​selects the lower limit path r from the path group P. 2 This is a function block for selecting the lower limit path r 2is the maximum exhaustion time T max Specifically, for example, the lower limit route selection unit 36 ​​selects routes from the destinations 5 whose locations have been aggregated by the relaxation problem in order of the sum (d'+p') of the grace time d' and the stay time p' as the lower limit route r 2 The lower limit path selection unit 36 ​​selects the selected lower limit path r 2 is transmitted to the lower limit calculation unit 37.

[0073] In addition, the above-mentioned lower limit route r 2 is the maximum depletion time T' at destination 5 whose location has been aggregated by the relaxation problem. max is minimized within the set of routes P. This can be easily proven by using the framework of minimizing delivery tardiness in scheduling problems.

[0074] In addition, the lower limit route r 2 In the above, if the resource is delivered to the delivery destination 5-i in the order of k, the relationship between i and k is expressed as in the following formula (6). However, if k=0, then i=0.

[0075]

number

[0076] The lower limit calculation unit 37 calculates the lower limit path r 2 Specifically, for example, the lower limit calculation unit 37 calculates the lower limit path r 2 The time a' when delivery truck 4 arrives at destination 5-i i (r 2 ) is calculated.

[0077]

number

[0078] Then, the lower limit calculation unit 37 calculates the arrival time a′ at the delivery destination 5-i according to the following formula (8): i (r 2 ) based on the lower limit for route r 2 The depletion time T' of destination 5-i at i (r 2 ) is calculated.

[0079]

number

[0080] Depletion time T' i (r 2 ) is the lower limit for the route r 2 Maximum depletion time T' max That is, the lower limit calculation unit 37 calculates the lower limit LB according to the following equation (9). The lower limit calculation unit 37 transmits the calculated lower limit LB to the second determination unit .

[0081]

number

[0082] The second judgment unit 38 is a functional block for judging whether or not to execute branching processing in the branch and bound method. The second judgment unit 38 judges whether or not the lower limit value LB is smaller than the evaluation function. If the lower limit value LB is smaller than the evaluation function, the second judgment unit 38 transmits the lower limit value LB to the branching unit 39. If the lower limit value LB is equal to or greater than the evaluation function, the second judgment unit 38 transmits the judgment result to the route management unit 23 without transmitting the lower limit value LB to the branching unit 39.

[0083] The branching unit 39 is a functional block for executing branching processing. The branching processing is processing for classifying a plurality of routes in the route group P into a plurality of sub-route groups P' each including at least one route. Specifically, for example, when the lower limit value LB is received from the second determination unit 38, the branching unit 39 classifies at least one route having a common first delivery destination 5 among the delivery destinations 5 in the route group P whose delivery order has not been determined, into the same sub-route group P'. The branching unit 39 transmits the generated sub-route group P' to the route management unit 23.

[0084] The output unit 25 is a functional block for outputting the optimal route to the user. When the route list L managed by the route management unit 23 becomes an empty set, the output unit 25 outputs the combination of the evaluation function stored by the update unit 33 and the route corresponding to the evaluation function to the user as the optimal route.

[0085] With the above-mentioned configuration, the user can receive information such as the maximum depletion time T max The route that minimizes the distance can be obtained as the optimal route. Then, the user can generate a delivery plan based on the information.

[0086] 2. Operation Next, the operation of the delivery support device according to the embodiment will be described.

[0087] 2.1 Delivery support operation 7 is a flowchart showing an example of a delivery support operation in the delivery support device according to the embodiment. In the example of FIG. 7, it is assumed that delivery vehicle information 22a, delivery destination information 22b, and travel time information 22c are stored in advance in the memory 12 by user input.

[0088] 7, when an instruction to select an optimal route is received from a user (start), the route management unit 23 initializes a route list L and an evaluation function (S11). For example, the route management unit 23 includes in the route list L all routes that can be realized by the destination 5 to which the resource is delivered. In addition, the route management unit 23 provisionally initializes the evaluation function to be minimized to infinity (=+∞).

[0089] The route management unit 23 determines whether the route list L is an empty set (S12).

[0090] If the route list L is not an empty set (S12; no), the route management unit 23 selects a route group P from the route list L, and deletes the selected route group P from the route list L (S13).

[0091] The upper limit path selection unit 30 selects an upper limit path r from the path group P selected in the process of S13. 1 Specifically, the upper limit route selection unit 30 selects a route on a plane that goes in order from the delivery destination 5 having the shortest grace time d as the upper limit route r 1 (S14).

[0092] The upper limit calculation unit 31 calculates the upper limit path r 1 Based on the maximum exhaustion time T max Then, an upper limit value UB of the minimum value of is calculated (S15).

[0093] The first judgment unit 32 judges whether or not the upper limit value UB calculated in the process of S15 is greater than the evaluation function (S16).

[0094] If the upper limit value UB is equal to or less than the evaluation function (S16; no), the update unit 33 updates the evaluation function to the upper limit value UB (S17). The update unit 33 also stores the updated upper limit value UB and the path corresponding to the upper limit value UB in the memory 12.

[0095] If the upper limit value UB is greater than the evaluation function (S16; yes), or after processing of S17, the relaxed problem setting unit 34 sets a relaxed problem of consolidating the delivery destinations 5 whose delivery order has not been determined within the route group P into a single point (S18).

[0096] After the process of S18, the idle time calculation unit 35 calculates the idle time It in the relaxed problem based on the travel time information 22c (S19).

[0097] The lower limit path selection unit 36 ​​selects a path on the point that is optimally selected based on the delivery tardiness minimization problem of the scheduling problem as the lower limit path r 2 Specifically, the lower limit route selection unit 36 ​​selects routes on points going to the destinations 5 that are collected at one point by the process of S18 in order of decreasing sum (d'+p') of the grace time d' and the stay time p' as the lower limit route r 2 (S20).

[0098] The lower limit calculation unit 37 calculates the lower limit path r 2 Based on the maximum exhaustion time T max A lower limit value LB of the minimum value of is calculated (S21).

[0099] The second judgment unit 38 judges whether or not the lower limit LB calculated in the process of S21 is smaller than the evaluation function (S22).

[0100] If the lower limit LB is smaller than the evaluation function (S22; yes), the branching unit 39 generates a sub-route group P' from the route group P and transmits the generated sub-route group P' to the route management unit 23 (S23). The route management unit 23 adds the sub-route group P' received from the branching unit 39 to the route list L as a new route group P.

[0101] If the lower limit LB is equal to or greater than the evaluation function (S22; no), or after the process of S23, the route management unit 23 judges whether the route list L is an empty set (S12). In this manner, the processes of S13 to S23 are repeated until the route list L becomes an empty set. This allows the evaluation function to be updated while selecting routes using the branch and bound method.

[0102] If the route list L is an empty set (S12; yes), the optimum route derivation unit 24 selects, as the optimum route, the route corresponding to the evaluation function finally updated by the process of S17 (S24).

[0103] When the process of S24 ends, the delivery support operation ends (ends), which enables the output unit 25 to output the selected optimal route to the user.

[0104] 2.2 Specific example of calculating the lower limit Next, a specific example of calculation of the lower limit LB in the relaxed problem will be described. In the following, it is assumed that the relaxed problem is applied to a route set P in which the delivery order to the delivery destinations 5-1 to 5-6 is not determined.

[0105] Fig. 8 is a diagram showing grace time and stay time in a specific example, Fig. 9 is a diagram showing movement time in a specific example, and Fig. 10 is a diagram showing idle time in a specific example.

[0106] As shown in Figure 8, vertex v 1 ~v 6 Consider the case where the grace period d and the stay period p in are given. That is, (d 1 ,p 1 )=(17,3), (d 2 ,p 2 )=(29,5), (d 3 ,p 3 )=(27,4), (d 4 ,p 4 )=(18,5), (d 5 ,p 5 )=(29,1), (d 6 ,p 6)=(18,6).

[0107] As shown in Figure 9, vertex v 0 ~v 6 Consider the case where the travel time between vertices in is given as t. That is, t(v 0 ,v 1 )=9.8, t(v 0 ,v 2 )=12.0, t(v 0 ,v 3 )=10.7, t(v 0 ,v 4 )=11.3, t(v 0 ,v 5 )=11.3, t(v 0 ,v 6 )=2.1, t(v 1 ,v 2 )=5.1, t(v 1 ,v 3 )=1.0, t(v 1 ,v 4 )=4.4, t(v 1 ,v 5 )=4.1, t(v 1 ,v 6 )=8.1, t(v 2 ,v 3 )=5.3, t(v 2 ,v 4 )=4.2, t(v 2 ,v 5 )=1.0, t(v 2 ,v 6 )=3.6, t(v 3 ,v 4 )=5.3, t(v 3 ,v 5 )=4.4, t(v 3 ,v 6 )=8.6, t(v 4 ,v 5 )=3.6, t(v 4 ,v 6 )=5.0, t(v 5 ,v 6 )=4.2.

[0108] The idle time calculation unit 35 calculates the idle time It as shown in FIG. 10 based on the above-mentioned moving time t and according to the above-mentioned formula (5). That is, the idle time calculation unit 35 calculates the idle time It as shown in FIG. 1 =1, It 2 =1, It 3 =1, It 4 =3.6, It 5 =1, It 6 Calculate = 3.6.

[0109] The lower limit route selection unit 36 ​​selects routes from the destination 5 having the smallest sum of the grace time d' and the stay time p' (d'+p') as the lower limit route r 2 Then select. As mentioned above, d i =d' i , p i =p' i Therefore, the destinations 5 with the smallest sum of the grace time d' and the residence time p' (d'+p') are 5-1, 5-4, 5-6, 5-5, 5-3, and 5-2 in this order. Therefore, the lower limit path selector 36 selects the route that delivers the resource in the order of vertices v'1→v'4→v'6→v'5→v'3→v'2 as the lower limit path r 2 Select as.

[0110] The lower limit calculation unit 37 calculates the arrival time a' according to the above-mentioned equation (7). i (r 2 Specifically, the lower limit calculation unit 37 calculates a' 1 (r 2 )=1.0, a' 4 (r 2 )=7.6, a' 6 (r 2 )=16.2, a' 5 (r 2 )=23.2, a' 3 (r 2 )=25.2, a' 2 (r 2 )=30.2.

[0111] The lower limit calculation unit 37 calculates the exhaustion time T' according to the above-mentioned equation (8). i (r 2Specifically, the lower limit calculation unit 37 calculates T' 1 (r 2 )=-16.0, T' 4 (r 2 )=-10.4, T' 6 (r 2 )=-1.8, T' 5 (r 2 )=-5.8, T' 3 (r 2 )=-1.8, T' 2 (r 2 The lower limit calculation unit 37 calculates the exhaustion time T' i (r 2 ) maximum value T' max =T' 2 (r 2 ) = 1.2 is calculated as the lower limit LB.

[0112] The lower limit LB is calculated by the above process. 0 from vertex v 1 ~v 6 The minimum delay time (optimum value) in the resource delivery route to is 16.5 by total counting. The lower limit LB is calculated to be below this optimal value. This ensures that the solution finally obtained by the branch and bound method using the relaxed problem set in this embodiment is an exact solution.

[0113] 1.3 Effects of the embodiment According to the embodiment, the optimal route derivation unit 24 derives an optimal route based on a branch-and-bound method using a relaxed problem of consolidating delivery destinations 5, whose delivery order has not been determined, into one point. It can be proven that an optimal solution can be obtained for such a relaxed problem by using the framework of a delivery tardiness minimization problem in a scheduling problem. This makes it possible to guarantee that the solution obtained by the branch-and-bound method using the relaxed problem is an exact solution.

[0114] Specifically, the lower limit route selection unit 36 ​​selects routes for delivery in ascending order of the sum of the grace time d' and the residence time p' as the lower limit route r 2 The lower limit calculation unit 37 selects the lower limit path r2 The maximum depletion time T' calculated based on max is calculated as the lower limit LB. This makes it possible to efficiently find the optimal delivery route for resources. Note that the grace period d' and sojourn time p' in the relaxed problem are set so as not to change from the grace period d and sojourn time p in the original problem, respectively. This ensures that the optimal values ​​obtained in the relaxed problem are always smaller than the optimal values ​​in the original problem.

[0115] Furthermore, the residence time p is set independently for each of the multiple delivery destinations 5. This makes it possible to derive a route that minimizes the maximum depletion time while taking into consideration cases in which the residence time p differs for each delivery destination 5.

[0116] In addition, the idle time calculation unit 35 calculates the idle time It according to the travel time t between the delivery destinations 5 by the delivery van 4. This makes it possible to reflect the settings of the original problem in the relaxed problem and to prevent the lower limit LB from deviating significantly from the optimal value of the original problem.

[0117] In addition, the upper limit route selection unit 30 selects routes for delivery in ascending order of grace time d as upper limit route r 1 The upper limit calculation unit 31 selects the upper limit path r 1 The maximum exhaustion time T is calculated based on max is calculated as the upper limit value UB. This makes it possible to update the value of the evaluation function in the branch and bound method.

[0118] In addition, the output unit 25 outputs the derived optimal route to the user. This allows the user to understand in what order the delivery vehicles 4 should be directed to the delivery destinations 5 in order to minimize the maximum depletion time. Therefore, the delivery support device 10 can support the creation of a more accurate delivery plan. 2. Other It should be noted that various modifications can be applied to the above-described embodiment.

[0119] For example, in the above-described embodiment, the delivery support program is executed by the delivery support device 10 in the delivery support center 2, but the present invention is not limited to this. For example, the delivery support management program may be executed by a computing resource on the cloud.

[0120] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the gist of the present invention. The embodiments may be combined as appropriate, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0121] 1. Delivery system 2. Delivery Support Center 3. Distribution base 4…Delivery vehicle 5-1, 5-2, 5-3, 5-4, 5-5, 5-6…Shipping destination 10…Delivery support device 11...Control circuit 12…Memory 13...Communication module 14...User Interface 15…Drive 16...Storage medium 21...Input section 22...Storage section 22a…Delivery vehicle information 22b…Shipping address information 22c…Travel time information 23…Route Management Department 24…Optimal route derivation section 25…Output section 30...Upper limit path selection section 31...Upper limit calculation section 32...1st judgment section 33…Update section 34... Mitigation problem setting part 35…Idle time calculation section 36...Lower limit value path selection section 37...Lower limit calculation section 38...Second judgment section 39...branch

Claims

1. a derivation unit that derives a route for the resource by the delivery device so as to minimize a maximum time for the resource to be depleted at a plurality of first locations; The derivation unit derives the route based on a branch-and-bound method using a relaxation problem of consolidating a plurality of second points, the delivery order of which has not been determined among the plurality of first points, into one point; Each of the plurality of first locations is associated with a depletion time of the resource and a residence time of the delivery equipment; The lead-out portion is a first route selection unit that selects a first route for delivering the resource to the second points based on the depletion time and the sum of the residence time; A first calculation unit that calculates a lower limit value of the maximum value based on the first path; a second route selection unit that selects a second route for delivering the resource to the plurality of first locations based on the depletion time; A second calculation unit that calculates an upper limit value of the maximum value based on the second path; Including, Delivery support equipment.

2. The residence times are independent of each other among the plurality of first locations. The delivery assistance device according to claim 1.

3. The derivation unit further includes a third calculation unit that calculates an idle time associated with each of the plurality of second points according to a travel time between the plurality of second points by the delivery device, The first calculation unit calculates the lower limit value further based on the idle time. The delivery assistance device according to claim 1.

4. The first path is an optimal solution based on a delivery tardiness minimization problem in a scheduling problem. The delivery assistance device according to claim 1.

5. A delivery assistance method using a delivery assistance device, comprising: deriving a route for a resource by a delivery device for minimizing a maximum time for the resource to be depleted at a plurality of first points based on a branch-and-bound method using a relaxation problem of consolidating a plurality of second points, the delivery order of which is not determined among the plurality of first points, into one point; Each of the plurality of first locations is associated with a depletion time of the resource and a residence time of the delivery equipment; The deriving step comprises: selecting a first route for delivering the resource to the plurality of second locations based on the exhaustion time and the sum of the residence times; calculating a lower limit of the maximum value based on the first path; selecting a second route for delivering the resource to the plurality of first locations based on the depletion time; calculating an upper limit of the maximum value based on the second path; Including, Shipping support methods.

6. A delivery support program for causing a computer to function as each unit of the delivery support device according to any one of claims 1 to 4.

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