Transportation Management System, Transportation Management Method, and Storage Medium

Abstract

The present invention relates to a transportation management system, a transportation management method, and a storage medium. The transportation management system includes: a receiving unit that receives p pieces of transportation task information indicating transportation tasks, each transportation task having a starting point and a destination; a connecting unit that generates q pieces of connection task information (q < p) by connecting the p pieces of transportation task information; and an allocation unit that allocates the q pieces of connection task information to q transportation robots respectively. The connecting unit generates the q pieces of connection task information such that the total travel distance is shortened, the total travel distance being the sum of the travel distances of the q transportation robots, the travel distance being the distance required for the q transportation robots to execute the q pieces of connection task information respectively.

Description

Technical Field

[0001] The present invention relates to a transportation management system, a transportation management method, and a storage medium. Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2020-83554 provides a technique in which when transporting a plurality of transportation target objects having different loading points and different unloading points, the loading points of the plurality of transportation target objects are visited to sequentially load the plurality of transportation target objects, a predetermined distance is traveled, and then the unloading points of the plurality of transportation target objects are visited to sequentially unload the plurality of transportation target objects, thereby shortening the time period required for the transportation task.

[0003] Moreover, JP 2020-83554A discloses that when a new transportation task is received while a plurality of transportation mobile devices are performing a transportation task, the transportation mobile device that can reach the loading point of the new transportation task earliest after completing the currently executed transportation task is identified, and the identified transportation mobile device is made to execute the new transportation task. Summary of the Invention

[0004] However, in the above JP 2020-83554A, there is still room for improvement in terms of transportation efficiency.

[0005] An object of the present invention is to provide a technique for improving transportation efficiency when performing a plurality of transportation tasks.

[0006] According to a first aspect of the invention of the present application, a transportation management system is provided, including: a receiving unit that receives p pieces of transportation task information indicating transportation tasks, each transportation task having a starting point and a destination; a connecting unit that generates q connection tasks (q < p) by connecting the p pieces of transportation task information; and an allocating unit that allocates the q pieces of connection task information to q transportation mobile devices respectively, wherein the connecting unit generates q pieces of connection task information such that the total driving distance becomes shorter, the total driving distance being the sum of the driving distances of the q transportation mobile devices, and the driving distance being the distance required for the q transportation mobile devices to execute the q pieces of connection task information respectively. With such a configuration, transportation efficiency can be improved when executing multiple transportation tasks. Preferably, the connecting unit calculates the inter-task driving distance generated when two different pieces of transportation task information among the p pieces of transportation task information are connected in sequence, and preferentially connects the two pieces of transportation task information that generate the shortest inter-task driving distance. With such a configuration, transportation efficiency can be further improved when executing multiple transportation tasks. Preferably, when the inter-task driving distance generated when a connection task information including at least two pieces of transportation task information is connected to another piece of transportation task information is not equal to or less than a predetermined value, the connecting unit does not connect the connection task information to the another piece of transportation task information. With such a configuration, it is possible to prevent all the transportation task information from being connected into a single connection task information. Preferably, it further includes a current position information acquisition unit that acquires current position information about each of the q transportation mobile devices, and the allocating unit allocates the q pieces of connection task information to the q transportation mobile devices respectively based on the starting point of the transportation task information at the beginning of each piece of connection task information and the current positions of the respective transportation mobile devices. With such a configuration, transportation efficiency can be further improved. Preferably, when the receiving unit receives new transportation task information while the q transportation mobile devices are respectively executing the q pieces of connection task information, the connecting unit generates q pieces of connection task information by reconnecting the unexecuted transportation task information, and when the q transportation mobile devices complete the currently executed pieces of transportation task information, the allocating unit allocates the reconnected q pieces of connection task information to the q transportation mobile devices respectively. With such a configuration, the newly received transportation task information can be received without difficulty. Preferably, the connecting unit connects the p pieces of transportation task information such that the difference between the driving distances of the q transportation mobile devices becomes smaller, the driving distance being the distance required for the q transportation mobile devices to execute the q pieces of connection task information respectively. With such a configuration, uneven loads on the transportation mobile devices can be suppressed.According to a second aspect of the invention of the present application, a transportation management method is provided, including: receiving p pieces of transportation task information indicating transportation tasks, each transportation task having a starting point and a destination; generating q pieces of connection task information (q < p) by connecting the p pieces of transportation task information; and respectively allocating the q pieces of connection task information to q transportation mobile devices, wherein generating the q pieces of connection task information is to generate the q pieces of connection task information such that the total driving distance is shortened, the total driving distance being the sum of the driving distances of the q transportation mobile devices, the driving distance being the distance required for the q transportation mobile devices to respectively execute the q pieces of connection task information. According to such a method, the transportation efficiency can be improved when multiple transportation tasks are executed. A storage medium is provided, which stores a program that causes a computer to execute the transportation management method.

[0007] According to the present invention, the transportation efficiency can be improved when multiple transportation tasks are executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The features, advantages, and technical and industrial significance of the exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals represent the same elements, and wherein:

[0009] Figure 1 is a functional block diagram of a transportation system;

[0010] Figure 2 is a control flow of a transportation management device;

[0011] Figure 3 shows transportation tasks;

[0012] Figure 4 shows transportation tasks;

[0013] Figure 5 shows transportation tasks;

[0014] Figure 6 is a conceptual diagram of the travel planning of a transportation robot;

[0015] Figure 7 is a diagram describing a method for searching for the shortest route of a transportation robot;

[0016] Figure 8 is a diagram describing a method for searching for the shortest route of a transportation robot;

[0017] Figure 9 is a diagram describing a method for searching for the shortest route of a transportation robot;

[0018] Figure 10 is a diagram describing a method for searching for the shortest route of a transportation robot;

[0019] Figure 11 is a diagram depicting a method for searching for the shortest route of a transport robot; and

[0020] Figure 12 is a diagram depicting a method for searching for the shortest route of a transport robot. Detailed implementation

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] Figure 1 A functional block diagram showing the transport system 1 is as follows Figure 1 As shown in the figure, the transport system 1 includes a transport management device 2 and a plurality of transport robots 3.

[0023] The transport management device 2 is a specific example of a transport management system. The transport management device 2 is implemented by a single device. However, the transport management device 2 can be implemented by a plurality of devices through distributed processing. Each transport robot 3 is a specific example of a transport mobile device capable of autonomous driving. In this embodiment, as an example, the transport system 1 includes two transport robots 3.

[0024] The transport management device 2 causes at least one of the transport robots 3 to execute a plurality of transport tasks. The transport management device 2 includes a central processing unit (CPU) 2a as a central processor, a readable and writable random access memory (RAM) 2b, and a read-only memory (ROM) 2c. The CPU 2a reads and executes a control program stored in the ROM 2c, so that the control program causes hardware such as the CPU 2a to function as a plurality of functional units. The plurality of functional units generally include a receiving unit 4, a connecting unit 5, an allocating unit 6, and a travel planning unit 7.

[0025] The receiving unit 4 receives p pieces of transport task information indicating transport tasks, and each transport task has a starting point and a destination of the transport task. P is a natural number equal to or greater than 2. The receiving unit 4 can receive a plurality of pieces of transport task information via an input device included in the transport management device 2, or can receive a plurality of pieces of transport task information via another device. The receiving unit 4 stores the received plurality of pieces of task information in the RAM 2b.

[0026] The connecting unit 5 generates q pieces of connection task information by connecting p pieces of transport task information. q is a natural number equal to or greater than 1 and less than p. In some cases, the connection task information may include only one piece of transport task information.

[0027] The allocating unit 6 allocates the q pieces of connection task information to q transport robots 3 respectively. The allocating unit 6 is also a specific example of a current position information acquisition unit.

[0028] The Travel Planning Department 7 generates travel planning information used when each transport robot 3 executes the assigned connection task information. The travel planning information is information indicating the travel route and passing time of the corresponding transport robot 3.

[0029] Each transport robot 3 is a robot capable of automatically traveling and transporting transport target objects. Each transport robot 3 includes a central processing unit (CPU) 3a as a central processor, a readable and writable random access memory (RAM) 3b, and a read-only memory (ROM) 3c. The CPU 3a reads and executes a control program stored in the ROM 3c, so that the control program causes hardware such as the CPU 3a to function as multiple functional units. The multiple functional units include a current position information acquisition unit 10 and a travel control unit 11.

[0030] The current position information acquisition unit 10 generally acquires current position information about the transport robot 3 by using a GPS module (not shown). Each transport robot 3 sends the acquired current position information to the transport management device 2.

[0031] The travel control unit 11 controls the travel of the transport robot 3 based on the travel planning information received from the transport management device 2.

[0032] Next, the control process of the transport management device 2 will be described with reference to Figures 2 to 12 Describe the control process of the transport management device 2.

[0033] S100

[0034] First, the receiving unit 4 of the transport management device 2 receives p pieces of transport task information. Here, refer to Figure 3 . Figure 3 Show transport tasks 1, 2, 3, 4. As an example, the receiving unit 4 of the transport management device 2 receives four pieces of transport task information regarding transport tasks 1 to 4.

[0035] Transport task 1 is a task of transporting a transport target object from the starting point o_1 to the destination d_1.

[0036] Transport task 2 is a task of transporting a transport target object from the starting point o_2 to the destination d_2.

[0037] Transport task 3 is a task of transporting a transport target object from the starting point o_3 to the destination d_3.

[0038] Transport task 4 is a task of transporting a transport target object from the starting point o_4 to the destination d_4.

[0039] Figure 3Each side of each square of the grid shown represents a unit distance. As an example, the unit distance is 50 meters. Thus, for example, the shortest distance between the starting point o_1 and the destination point d_2 is 2, and the shortest distance between the starting point o_1 and the destination point d_1 is 8.

[0040] S110

[0041] The connection unit 5 of the transportation management device 2 generates two connection task information by connecting four transportation task information. In other words, the connection unit 5 generates two sets of connection tasks by connecting four transportation tasks. In the present embodiment, since a plurality of transportation tasks are assigned to two transportation robots 3, the connection unit 5 generates two sets of connection tasks by connecting four transportation tasks. The connection unit 5 generates two sets of connection tasks such that the total travel distance (i.e., the sum of the travel distances of the two transportation robots 3 required for the two transportation robots 3 to execute the two sets of connection tasks respectively) is the shortest. Here, the term "travel distance" means the distance that each transportation robot 3 travels from the starting point of the transportation task at the beginning of the assigned connection task to the destination point of the transportation task at the end.

[0042] First, the connection unit 5 calculates the inter-task travel distance generated when two different transportation tasks among the four transportation tasks are connected in sequence, and preferentially connects the two transportation tasks that generate the shortest inter-task travel distance.

[0043] In other words, the connection unit 5 calculates the inter-task travel distance between the starting point o_i of the transportation task i and the destination point d_j (j≠i) of the transportation task j, and calculates the minimum value of the inter-task travel distance according to the following expressions (1) to (4). Note that in expressions (1) to (4), "dis(a, b)" represents the shortest distance between the point "a" and the set "b". Thus, for example, according to expression (1), the connection unit 5 calculates the inter-task travel distance between the starting point o_1 and the destination point d_2, calculates the inter-task travel distance between the starting point o_1 and the destination point d_3, calculates the inter-task travel distance between the starting point o_1 and the destination point d_4, and thus calculates that the minimum value of the inter-task travel distance is 2.

[0044] dis(o_1,{d_2,d_3,d_4})=2…(1)

[0045] dis(o_2,{d_1,d_3,d_4})=3…(2)

[0046] dis(o_3,{d_1,d_2,d_4})=5…(3)

[0047] dis(o_4,{d_1,d_2,d_3})=5…(4)

[0048] According to expression (1), the destination point closest to the starting point o_1 is the destination point d_2.

[0049] According to expression (2), the destination point closest to the starting point o_2 is the destination point d_1.

[0050] According to expression (3), the destination points closest to the starting point o_3 are the destination points d_1, d_2, d_4.

[0051] According to expression (4), the destination points closest to the starting point o_4 are the destination points d_1, d_2.

[0052] According to expressions (1) to (4), in expression (1), the minimum value of the travel distance between tasks is 2, and this travel distance between tasks is achieved by connecting transportation task 2 and 1 in sequence. Therefore, compared with other connections, the connecting part 5 preferentially connects transportation task 2 and 1 in sequence. Hereinafter, the connection task obtained by connecting transportation task 2 and 1 in sequence is denoted as "connection task 2→1". In other words, the connecting part 5 generates the connection task 2→1 by connecting transportation task 2 and 1 in sequence.

[0053] According to expression (2), it is recommended to connect transportation task 1 and 2 in sequence. However, the connection task obtained by connecting transportation task 1 and 2 in sequence is exclusive to the connection task 2→1. Therefore, the connecting part 5 does not generate the connection task obtained by connecting transportation task 1 and 2 in sequence.

[0054] According to expression (3), it is recommended that: (a) connect transportation task 1 and 3 in sequence; (b) connect transportation task 2 and 3 in sequence; and (c) connect transportation task 4 and 3 in sequence.

[0055] (a)

[0056] Connecting transportation task 1 and 3 in sequence means connecting the connection task 2→1 and transportation task 3 in sequence. When connecting transportation task 1 and 3 in sequence, the travel distance between tasks is 5. The connecting part 5 compares the travel distance between tasks with a predetermined value, and when the travel distance between tasks is not equal to or less than the predetermined value, it does not connect the connection task 2→1 and transportation task 3. Here, the predetermined value is usually 2. Since the travel distance between tasks is not equal to or less than 2, the connecting part 5 does not connect the connection task 2→1 and transportation task 3 in sequence.

[0057] Configure so that the connection task and another transportation task are connected only when the travel distance between tasks is equal to or less than the predetermined value described above, thereby preventing all transportation tasks from being connected into a single sequence. Note that when there are n transportation tasks, the travel distance between tasks between the starting point and the destination point considered for connection can be sorted in descending order, and the k-th value can be used as the predetermined value. In addition, the distance between the starting point and the destination point required to connect the 1st to the (k - 1)-th transportation tasks can be set to L or less, and the distance required to connect the k-th and subsequent transportation tasks can be set to M (M > L) or less.

[0058] (b)

[0059] Connecting transportation tasks 2 and 3 in sequence is exclusive to the preferentially adopted connection task 2→1. Therefore, the connecting part 5 does not connect transportation tasks 2 and 3 in sequence.

[0060] (c)

[0061] The connecting part 5 connects transportation tasks 4 and 3 in sequence. Hereinafter, the connection task obtained by connecting transportation tasks 4 and 3 in sequence will be denoted as "connection task 4→3".

[0062] According to Expression (4), it is recommended that: (a) connect transportation tasks 1 and 4 in sequence; and (b) connect transportation tasks 2 and 4 in sequence.

[0063] (a)

[0064] Connecting transportation tasks 1 and 4 in sequence means connecting the connection task 2→1 and transportation task 4 in sequence. When connecting transportation tasks 1 and 4 in sequence, the travel distance between tasks is 5. Therefore, since the travel distance between tasks is not equal to or less than 2, the connecting part 5 does not connect the connection task 2→1 and transportation task 4 in sequence.

[0065] (b)

[0066] Connecting transportation tasks 2 and 4 in sequence is exclusive to the preferentially adopted connection task 2→1. Therefore, the connecting part 5 does not connect transportation tasks 2 and 4 in sequence.

[0067] As a result, the connecting part 5 connects transportation tasks 1 to 4 to generate the connection task 2→1 and the connection task 4→3.

[0068] If the transportation tasks 1 to 4 are executed by a transportation robot 3, the connection part 5 further connects the connection tasks 2→1 and 4→3. In this case, when the connection tasks 2→1 and 4→3 are connected in sequence, the inter-task travel distance, which is the distance between the destination point d_1 and the starting point o_4, is 5. On the other hand, when the connection tasks 4→3 and 2→1 are connected in sequence, the inter-task travel distance, which is the distance between the destination point d_3 and the starting point o_2, is 4. Therefore, the connection part 5 connects the connection tasks 4→3 and 2→1 in sequence, making the travel distance of the transportation robot 3 the shortest, and generates the connection task 4→3→2→1.

[0069] S120

[0070] Next, the allocation unit 6 allocates the connection tasks 2→1 and 4→3 to two transportation robots 3 respectively. Specifically, the allocation unit 6 receives and obtains the current position information from the two transportation robots 3. Then, based on the starting point o_2 of the transportation task 2, which is the starting task of the connection task 2→1, the starting point o_4 of the transportation task 4, which is the starting task of the connection task 4→3, and the respective current positions of the two transportation robots 3, the allocation unit 6 allocates the connection tasks 2→1 and 4→3 to the two transportation robots 3 respectively.

[0071] Here, for ease of description, the two transportation robots 3 are referred to as "transportation robot 3A" and "transportation robot 3B". First, the allocation unit 6 calculates the total value of the distance between the transportation robot 3A and the starting point o_2 and the distance between the transportation robot 3B and the starting point o_4, and the total value of the distance between the transportation robot 3A and the starting point o_4 and the distance between the transportation robot 3B and the starting point o_2, and compares the two total values. Then, based on the comparison result, the allocation unit 6 allocates the connection tasks 2→1 and 4→3 to the two transportation robots 3 respectively. In other words, the allocation unit 6 allocates the connection tasks 2→1 and 4→3 to the two transportation robots 3 such that the total travel distance required before each transportation robot 3 starts executing the allocated connection task is the shortest.

[0072] S130

[0073] Subsequently, the travel planning unit 7 generates travel planning information to be used when each transportation robot 3 executes the allocated connection task.

[0074] S140

[0075] The travel management device 2 sends the travel planning information generated by the travel planning unit 7 to each transportation robot 3. The travel control unit 11 of each transportation robot 3 executes the allocated connection task information based on the received travel planning information.

[0076] Next, a description will be given of the case where the receiving unit 4 receives a new transportation task while two transportation robots 3 are respectively performing two sets of connection tasks. In this case, the connection unit 5 generates two sets of connection tasks by reconnecting the unexecuted transportation tasks. Then, when the two transportation robots 3 complete their respective current transportation tasks, the allocation unit 6 allocates the two reconnected sets of connection tasks to the two transportation robots 3 respectively. The process of reconnecting the unexecuted transportation tasks is exactly the same as the above-described process. Hereinafter, based on Figure 4 the case of adding a new transportation task will be described.

[0077] First, the connection unit 5 calculates the inter-task travel distance generated when two different transportation tasks among the five transportation tasks are connected in sequence, and preferentially connects the two transportation tasks that generate the shortest inter-task travel distance.

[0078] In other words, the connection unit 5 calculates the inter-task travel distance between the starting point o_i of transportation task i and the destination d_j (j≠i) of transportation task j, and calculates the minimum value of the inter-task travel distance according to the following expressions (1) to (5). For example, according to expression (1), the connection unit 5 calculates the inter-task travel distance between the starting point o_1 and the destination d_2, calculates the inter-task travel distance between the starting point o_1 and the destination d_3, calculates the inter-task travel distance between the starting point o_1 and the destination d_4, calculates the inter-task travel distance between the starting point o_1 and the destination d_new, and thus calculates that the minimum value of the inter-task travel distance is 2.

[0079] dis(o_1,{d_2,d_3,d_4,d_new})=2…(1)

[0080] dis(o_2,{d_1,d_3,d_4,d_new})=3…(2)

[0081] dis(o_3,{d_1,d_2,d_4,d_new})=4…(3)

[0082] dis(o_4,{d_1,d_2,d_3,d_new})=2…(4)

[0083] dis(o_new,{d_1,d_2,d_3,d_4})=3…(5)

[0084] According to expression (1), the destination closest to the starting point o_1 is the destination d_2.

[0085] According to expression (2), the destination closest to the starting point o_2 is the destination d_1.

[0086] According to expression (3), the destination point closest to the starting point o_3 is the destination point d_new.

[0087] According to expression (4), the destination point closest to the starting point o_4 is the destination point d_new.

[0088] According to expression (5), the destination point closest to the starting point o_new is the destination point d_3.

[0089] According to expressions (1) to (5), the minimum value of the travel distance between tasks in expressions (1) and (4) is 2, and such a travel distance between tasks is achieved by sequentially connecting transportation tasks 2 and 1 and by sequentially connecting transportation tasks new and 4. Moreover, such connections are not mutually exclusive. Therefore, the connection part 5 preferentially connects transportation tasks 2 and 1 sequentially and connects transportation tasks new and 4 sequentially over other connections. Hereinafter, the connection task obtained by sequentially connecting transportation tasks 2 and 1 will be denoted as "connection task 2→1". The connection task obtained by sequentially connecting transportation tasks new and 4 will be denoted as "connection task new→4".

[0090] According to expression (2), it is recommended to sequentially connect transportation tasks 1 and 2. However, the connection task obtained by sequentially connecting transportation tasks 1 and 2 is exclusive to the connection task 2→1. Therefore, the connection part 5 does not sequentially connect transportation tasks 1 and 2.

[0091] According to expression (3), it is recommended to sequentially connect transportation tasks new and 3. However, the connection task obtained by sequentially connecting transportation tasks new and 3 is exclusive to the connection task new→4. Therefore, the connection part 5 does not sequentially connect transportation tasks new and 3.

[0092] According to expression (5), it is recommended to sequentially connect transportation tasks 3 and new. Moreover, the connection task obtained by sequentially connecting transportation tasks 3 and new is not exclusive to the connection task 2→1 or the connection task new→4. Therefore, the connection part 5 sequentially connects transportation task 3 and the connection task new→4. Hereinafter, the connection task obtained by sequentially connecting transportation task 3 and the connection task new→4 will be denoted as "connection task 3→new→4".

[0093] After that, the allocation part 6 allocates the connection task 2→1 and the connection task 3→new→4 to two transportation robots 3 respectively.

[0094] Next, with reference to Figure 5 , a description of the case where some transportation tasks have the same starting point will be given. Figure 5 Transportation tasks 11, 12, 21, 22, 3 are shown.

[0095] Transport task 11 is a task of transporting a transport target object from the starting point o_1 to the destination d_11.

[0096] Transport task 12 is a task of transporting a transport target object from the starting point o_1 to the destination d_21.

[0097] Transport task 21 is a task of transporting a transport target object from the starting point o_2 to the destination d_21.

[0098] Transport task 22 is a task of transporting a transport target object from the starting point o_2 to the destination d_22.

[0099] Transport task 3 is a task of transporting a transport target object from the starting point o_3 to the destination d_3.

[0100] Figure 5 Each side of each square of the grid shown represents twice the unit distance. The unit distance is, for example, 50 meters. Thus, for example, the shortest distance between the starting point o_1 and the destination d_3 is 4, and the shortest distance between the starting point o_1 and the destination d_12 is 7.

[0101] Similarly in Figure 5 the example of, the method of connecting multiple transport tasks by the connecting part 5 is the same as the above method.

[0102] First, the connecting part 5 calculates the inter-task travel distance generated when two different transport tasks among the five transport tasks are connected in sequence, and preferentially connects the two transport tasks that generate the shortest inter-task travel distance.

[0103] In other words, the connecting part 5 calculates the inter-task travel distance between the starting point o_i of the transport task i and the destination d_j (j≠i) of the transport task j, and calculates the minimum value of the inter-task travel distance according to the following formulas (1) to (3).

[0104] dis(o_1,{d_21,d_22,d_3})=4…(1)

[0105] dis(o_2,{d_11,d_12,d_3})=2…(2)

[0106] dis(o_3,{d_11,d_12,d_21,d_22})=4…(3)

[0107] According to expression (1), the destination closest to the starting point o_1 is the destination d_3.

[0108] According to expression (2), the destination closest to the starting point o_2 is the destination d_11.

[0109] According to Expression (3), the destination points closest to the starting point o_3 are destination points d_11, d_21, and d_22.

[0110] According to Expressions (1) to (3), the minimum value of the travel distance between tasks in Expression (2) is 2, and such a travel distance between tasks is achieved by sequentially connecting transportation tasks 11 and 21 or sequentially connecting transportation tasks 11 and 22. Therefore, the connecting part 5 preferentially connects transportation tasks 11 and 21 sequentially or connects transportation tasks 11 and 22 sequentially over other connections. Hereinafter, the connecting task obtained by sequentially connecting transportation tasks 11 and 21 will be denoted as "connecting task 11→21". The connecting task obtained by sequentially connecting transportation tasks 11 and 22 will be denoted as "connecting task 11→22".

[0111] According to Expression (1), it is recommended to sequentially connect transportation tasks 3 and 11 and sequentially connect transportation tasks 3 and 12. Hereinafter, the connecting task obtained by sequentially connecting transportation tasks 11 and 21 will be denoted as "connecting task 3→11". The connecting task obtained by sequentially connecting transportation tasks 3 and 12 will be denoted as "connecting task 3→12".

[0112] According to Expression (3), it is recommended to sequentially connect transportation tasks 11 and 3, sequentially connect transportation tasks 21 and 3, and sequentially connect transportation tasks 22 and 3. However, the connecting task obtained by sequentially connecting transportation tasks 11 and 3 is exclusive to the sequential connection of transportation tasks 11 and 21 or the sequential connection of transportation tasks 11 and 22. Therefore, the connecting part 5 does not sequentially connect transportation tasks 11 and 3. Hereinafter, the connecting task obtained by sequentially connecting transportation tasks 21 and 3 will be denoted as "connecting task 21→3". The connecting task obtained by sequentially connecting transportation tasks 22 and 3 will be denoted as "connecting task 22→3".

[0113] In other words, according to Expressions (1) to (3), the connecting tasks 11→21 and 11→22 are recommended as the preferentially adopted connecting tasks, and the connecting tasks 3→11, 3→12, 21→3, and 22→3 are recommended as other candidates.

[0114] According to such a recommendation, for example, when transportation tasks 11, 12, 21, 22, and 3 are assigned to three transportation robots 3, the following combinations of connecting tasks can be considered. Note that the numbers in parentheses represent the travel distance required to execute the corresponding connecting task.

[0115] (Case 1A)

[0116] Connection task 3→12(15), connection task 11→22(16), connection task 21(8)

[0117] (Case 1B)

[0118] Connection task 12(7), connection task 11→22(16), connection task 21→3(16)

[0119] (Case 2A)

[0120] Connection task 3→12(15), connection task 11→21(18), connection task 22(6)

[0121] (Case 2B)

[0122] Connection task 12(7), connection task 11→21(18), connection task 22→3(14)

[0123] (Case 3A)

[0124] Connection task 3→11(16), connection task 11→22(16), connection task 21(8)

[0125] (Case 3B)

[0126] Connection task 11(8), connection task 11→22(16), connection task 21→3(16)

[0127] (Case 4A)

[0128] Connection task 3→11(16), connection task 11→21(18), connection task 22(6)

[0129] (Case 4B)

[0130] Connection task 11(8), connection task 11→22(18), connection task 22→3(14)

[0131] Note that connection task 11 is a connection task that only includes transportation task 11. The same applies to connection tasks 12, 21, and 22.

[0132] Then, the connection unit 5 generates three sets of connection tasks such that the total travel distance, which is the sum of the travel distances of the three transportation robots 3 required for the three transportation robots 3 to execute the three sets of connection tasks respectively, becomes shorter. The total travel distance in each of Cases 1A, 1B, 2A, and 2B is 39. The total travel distance in each of Cases 3A, 3B, 4A, and 4B is 40. Therefore, the connection unit 5 determines to follow any one of Cases 1A, 1B, 2A, and 2B.

[0133] In addition, the connection unit 5 connects the five transportation tasks such that the difference between the travel distances of the three transportation robots 3 required for the three transportation robots 3 to respectively execute three sets of connection tasks becomes smaller. The variance of the travel distances required for the three transportation robots 3 to execute the three sets of connection tasks belonging to Case 1A is 12.7. The variance in Case 1B is 18. The variance in Case 2A is 26. The variance in Case 2B is 20.7. Therefore, when Case 1A is adopted, the difference between the travel distances of the three transportation robots 3 required for the three transportation robots 3 to respectively execute three sets of connection tasks is the smallest. Therefore, the connection unit 5 connects the five transportation tasks according to Case 1A and generates three sets of connection tasks.

[0134] After that, the allocation unit 6 allocates the three sets of connection tasks to the three transportation robots 3 respectively.

[0135] Note that the connection method in the case of allocating the five transportation tasks to two transportation robots 3 and in the case of allocating the five transportation tasks to one transportation robot 3 follows the above connection method.

[0136] For example, when the five transportation tasks are allocated to two transportation robots 3, the connection unit 5 connects the five transportation tasks in consideration of the total travel distance and variance, and generates connection task 11→21 and connection task 22→3→12.

[0137] For example, when the five transportation tasks are allocated to one transportation robot 3, the connection unit 5 connects the five transportation tasks in consideration of the total travel distance, and generates connection task 11→22→3→11→21.

[0138] Next, the operation of the travel planning unit 7 will be described with reference to Figures 6 to 12 As described above, the travel planning unit 7 generates travel planning information used when each transportation robot 3 executes the allocated transportation task.

[0139] The travel planning unit 7 searches for the shortest route with fewer direction changes from the starting point to the destination of each transportation task. As Figure 6 shown, the travel planning unit 7 generates travel planning information for each transportation robot 3 such that the transportation robots 3 do not collide with each other on the found shortest route or on a route obtained by locally changing the shortest route. The travel planning information is information indicating the travel route and the passing time of the corresponding transportation robot 3. The travel route usually includes multiple nodes and connections connecting multiple nodes. The passing time is usually the time of passing through each node.

[0140] Hereinafter, a method for creating the shortest route with fewer direction changes between the starting point and the destination will be described with reference to Figures 7 to 12 A service environment in which there are multiple obstacles Q is shown. In Figure 7 Figure 7In the service environment shown, by way of example, there are obstacles Q1, Q2, and Q3.

[0141] When creating the shortest route from the starting point to the destination point, the travel planning unit 7 generates an upper L-shaped route 30 and a lower L-shaped route 31. The upper L-shaped route 30 is a route that makes one right turn from the starting point until the destination point. The upper L-shaped route 30 includes a first upper L-shaped route 30a that extends vertically from the starting point and a second upper L-shaped route 30b that is horizontal and continues from the first upper L-shaped route 30a until the destination point. The lower L-shaped route 31 is a route that makes one left turn from the starting point until the destination point. The lower L-shaped route 31 includes a first lower L-shaped route 31a that extends horizontally from the starting point and a second lower L-shaped route 31b that is vertical and continues from the first lower L-shaped route until the destination point.

[0142] The travel planning unit 7 determines whether the first lower L-shaped route 31a of the lower L-shaped route 31 is blocked by any of the multiple obstacles Q, and when there is no blockage, searches for the shortest route based on the lower L-shaped route 31, and when there is a blockage, searches for the shortest route based on the upper L-shaped route 30. In Figure 7 the example, the first lower L-shaped route 31a of the lower L-shaped route 31 is not blocked by any of the multiple obstacles Q. Therefore, the travel planning unit 7 generates the shortest route based on the lower L-shaped route 31.

[0143] Next, the travel planning unit 7 determines whether the second lower L-shaped route 31b of the lower L-shaped route 31 is blocked by any of the multiple obstacles Q. When there is a blockage, the travel planning unit 7 translates the second lower L-shaped route 31b one square towards the starting point side, and generates a partial upper L-shaped route that includes the second lower L-shaped route 31b and a horizontal route that continues from the second lower L-shaped route 31b until the destination point. In Figure 7 the example, the second lower L-shaped route 31b of the lower L-shaped route 31 is blocked by the obstacle Q1. Therefore, as Figure 8 and Figure 9 shown, the travel planning unit 7 translates the second lower L-shaped route 31b towards the starting point side, and generates a partial upper L-shaped route 32 that includes the second lower L-shaped route 31b and a horizontal route 31c that continues from the second lower L-shaped route 31b until the destination point.

[0144] By repeating the same process, the travel planning unit 7 obtains a passable route 33 as the Figure 10 partial upper L-shaped route 32 shown.

[0145] Next, as Figure 11 shown, the travel planning unit 7 generates a partial lower L-shaped route 34 to generate a passable route. When a passable route based on the partial lower L-shaped route is not found, the travel planning unit 7 further searches for a passable route based on the partial upper L-shaped route. InFigure 11 In this case, it reaches the destination point through the partial upper L-shaped route 35. Therefore, as the shortest route from the starting point to the destination point, the travel planning unit 7 generates a shortest route including the lower L-shaped route 31, the partial upper L-shaped route 32, the partial lower L-shaped route 34, and the partial lower L-shaped route 35.

[0146] The travel planning unit 7 generates a shortest route for each transport robot 3. In other words, for each transport robot 3, the travel planning unit 7 generates a shortest route from the current position of the transport robot 3 to the starting point of the transport task at the beginning of the connection task assigned to the transport robot 3, and a shortest route from the starting point of the transport task at the beginning of the connection task to the destination point of the transport task at the end.

[0147] Here, it is assumed that each transport robot 3 travels one square along the shortest route per unit time, and when multiple transport robots 3 pass through the same position (node) simultaneously, the travel planning unit 7 gives priority to the transport robot 3 closer to the destination point over other transport robots 3, and the other transport robots 3 stay at the current position for one unit time. Therefore, it is possible to ensure more quickly the transport robots 3 that have completed the connection task and have free time. When the distances of multiple transport robots 3 to their respective destination points are the same, the transport robot 3 that has traveled a longer distance from the starting point is allowed to pass through the node prior to other transport robots 3. When the distances of multiple transport robots 3 to their respective destination points are the same, and when the distances of multiple transport robots 3 to their respective starting points are also the same, the travel planning unit 7 randomly determines the transport robot 3 that passes through the node prior.

[0148] Note that the travel planning unit 7 can correct the shortest route so as not to pass through frequently used nodes or connections. In this case, as Figure 12 shown, by assuming that the corner of the partial L-shape is a partial destination point, the travel planning unit 7 locally corrects the shortest route, such as by making a local route change P1 or a local route change P2.

[0149] The preferred embodiments of the invention of the present application have been described above, and the embodiments include the following features.

[0150] The transportation management device 2 (transportation management system) includes: a receiving unit 4 that receives p pieces of transportation task information indicating transportation tasks, each transportation task having a starting point and a destination; a connecting unit 5 that generates q connection tasks (q < p) by connecting the p pieces of transportation task information; and an allocation unit 6 that allocates the q pieces of connection task information to q transportation robots (transportation mobile devices) respectively. The connecting unit 5 generates q pieces of connection task information such that the total travel distance becomes shorter, the total travel distance being the sum of the travel distances of the q transportation robots 3, and the travel distance being the distance required for the q transportation robots 3 to execute the q pieces of connection task information respectively. With such a configuration, when executing multiple transportation tasks, the transportation efficiency can be improved.

[0151] The connecting unit 5 calculates the inter-task travel distance generated when two different pieces of transportation task information among the p pieces of transportation task information are connected in sequence, and preferentially connects the two pieces of transportation task information that generate the shortest inter-task travel distance. With such a configuration, when executing multiple transportation tasks, the transportation efficiency can be further improved.

[0152] When the inter-task travel distance generated when a connection task information including at least two pieces of transportation task information is connected to another piece of transportation task information is not equal to or less than a predetermined value, the connecting unit 5 does not connect the connection task information to the other piece of transportation task information. With such a configuration, it is possible to prevent all the transportation task information from being connected into a single piece of connection task information.

[0153] The transportation management device 2 further includes an allocation unit 6 (current position information acquisition unit) that acquires the current position information of each of the q transportation robots 3 regarding the q transportation robots 3. The allocation unit 6 allocates the q pieces of connection task information to the q transportation robots 3 respectively based on the starting point of the transportation task information at the beginning of each piece of connection task information and the current positions of the respective transportation robots 3. Since each piece of connection task information can be allocated to the transportation robot 3 closest to the starting point of the starting transportation information of the connection task information, the transportation efficiency can be further improved.

[0154] When the receiving unit 4 receives new transportation task information while the q transportation robots 3 are respectively executing the q pieces of connection task information, the connecting unit 5 generates q pieces of connection task information by reconnecting the unexecuted transportation task information. When the q transportation robots 3 complete the respective pieces of transportation task information currently being executed, the allocation unit 6 allocates the reconnected q pieces of connection task information to the q transportation robots 3 respectively. With such a configuration, it is possible to receive the newly received transportation task information without difficulty.

[0155] The connection unit 5 connects p pieces of transportation task information, reducing the difference in travel distances among q transportation robots 3. The travel distances are those required for the q transportation robots 3 to execute q pieces of connection task information respectively. With such a configuration, the uneven load on the transportation robots 3 can be restricted.

[0156] A transportation management method includes: receiving p pieces of transportation task information indicating transportation tasks, each transportation task having a starting point and a destination; generating q (q < p) pieces of connection task information by connecting the p pieces of transportation task information; and respectively allocating the q pieces of connection task information to q transportation robots 3. Generating the q pieces of connection task information is to generate the q pieces of connection task information such that the total travel distance becomes shorter. The total travel distance is the sum of the travel distances of the q transportation robots 3, and the travel distance is the distance required for each of the q transportation robots 3 to execute the q pieces of connection task information. With such a method, the transportation efficiency can be improved when multiple transportation tasks are executed.

[0157] In the above example, the program can be provided to a computer by any of various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic storage media (such as floppy disks, magnetic tapes, hard disk drives) and magneto-optical storage media (such as magneto-optical discs). Examples of non-transitory computer-readable media also include CD read-only memories (CD-ROMs), CD-Rs, and CD-R / Ws, as well as semiconductor memories (such as those including mask ROMs); examples of non-transitory computer-readable media also include programmable ROMs (PROMs), erasable PROMs (EPROMs), flash ROMs, and random access memories (RAMs). In addition, the program can be provided to a computer using any of various types of transitory computer-readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transitory computer-readable media can provide the program to a computer through a wired communication path (such as wires or optical fibers) or a wireless communication path.

Claims

1. A transportation management system, comprising: a receiving unit that receives p pieces of transportation task information indicating transportation tasks, each of the transportation tasks having a starting point and a destination; a connecting unit that generates q pieces of connection task information by connecting the p pieces of transportation task information, where q < p; and a distributing unit that distributes the q pieces of connection task information to q transportation mobile devices respectively, wherein the connecting unit generates the q pieces of connection task information such that the total driving distance becomes shorter, the total driving distance being the sum of the driving distances of the q transportation mobile devices, the driving distance being the distance required for the q transportation mobile devices to respectively execute the q pieces of connection task information; wherein when the inter-task driving distance generated when a connection task information including at least two pieces of transportation task information is connected to another piece of transportation task information is not equal to or less than a predetermined value, the connecting unit does not connect the connection task information to the another piece of transportation task information.

2. The transportation management system according to claim 1, wherein, The connecting unit calculates the inter-task driving distance generated when two different pieces of transportation task information among the p pieces of transportation task information are connected in sequence, and preferentially connects the two pieces of transportation task information that generate the shortest inter-task driving distance.

3. The transportation management system according to claim 1 or 2, further comprising a current position information acquisition unit that acquires current position information about each of the q transportation mobile devices, Among them, wherein the distributing unit distributes the q pieces of connection task information to the q transportation mobile devices respectively based on the starting point of the transportation task information at the beginning of each piece of connection task information and the current positions of the respective transportation mobile devices.

4. The transportation management system according to claim 1 or 2, wherein when the receiving unit receives new transportation task information while the q transportation mobile devices are respectively executing the q pieces of connection task information, the connecting unit generates q pieces of connection task information by reconnecting the unexecuted transportation task information, and when the q transportation mobile devices complete the respective pieces of transportation task information currently being executed, the distributing unit distributes the reconnected q pieces of connection task information to the q transportation mobile devices respectively.

5. The transportation management system according to claim 1 or 2, wherein, The connecting unit connects the p pieces of transportation task information such that the difference between the driving distances of the q transportation mobile devices becomes smaller, the driving distance being the distance required for the q transportation mobile devices to respectively execute the q pieces of connection task information.

6. A transportation management method, comprising: receiving p pieces of transportation task information indicating transportation tasks, each of the transportation tasks having a starting point and a destination; generating q pieces of connection task information by connecting the p pieces of transportation task information, where q < p; and distributing the q pieces of connection task information to q transportation mobile devices respectively, Among them, generating the q connection task information is to generate the q connection task information so that the total driving distance becomes shorter. The total driving distance is the sum of the driving distances of the q transportation mobile devices, and the driving distance is the distance required for the q transportation mobile devices to execute the q connection task information respectively; Among them, the transportation management method further includes: When the inter-task driving distance generated when the connection task information including at least two transportation task information is connected to another transportation task information is not equal to or less than a predetermined value, the connection task information is not connected to the another transportation task information.

7. A storage medium storing a program that causes a computer to execute the transportation management method according to claim 6.

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