Node reduction-based optimal path calculation method, apparatus, and system

Abstract

The present invention relates to a node reduction-based optimal path calculation method, apparatus, and system. More specifically, it relates to a node reduction-based optimal path calculation method, apparatus, and system that can effectively calculate an optimal path from a starting node to a destination node based on a graph including a plurality of nodes corresponding to a working space in a logistics automation system. In the present invention, there is provided a method for calculating an optimal path from a first node to a second node based on a graph configured to include a plurality of nodes corresponding to a working space and edges connecting between the plurality of nodes, the method comprising: a representative node calculation step of calculating, by an optimal path calculation system, a first representative node corresponding to the first node and a second representative node corresponding to the second node from among a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes; a representative node optimal path calculation step of calculating a representative node optimal path from the first representative node to the second representative node; and an optimal path calculation step of calculating an optimal path from the first node to the second node in consideration of the representative node optimal path, a distance difference (offset) from the first representative node to the first node, and a distance difference (offset) from the second representative node to the second node. An optimal path calculation method characterized by including the above steps is disclosed.

Description

Technical Field

[0001] The present invention relates to a node reduction-based optimal path calculation method, apparatus, and system. More specifically, the present invention relates to a node reduction-based optimal path calculation method, apparatus, and system that can effectively calculate an optimal path from a starting node to a destination node based on a graph including a plurality of nodes corresponding to a work space in a logistics automation system.

Background Art

[0002] In recent years, with the growth of e-commerce and the spread of factory automation, logistics automation systems that efficiently process the transportation of goods while minimizing the intervention of workers have been widely used.

[0003] More specifically, for example, in a logistics warehouse or factory, products and parts are transported using logistics robots such as Automated Guided Vehicles (AGVs) or Autonomous Mobile Robots, or in a semiconductor factory, wafers are transported using an Overhead Hoist Transport (OHT) device, etc., in order to automate logistics, improve work efficiency, and reduce costs. Various attempts have been made.

[0004] More specifically, in Amazon's Kiva system illustrated in FIG. 1, more than 200,000 Automated Guided Vehicles (AGVs) 10 are operated in logistics warehouses around the world, thereby reducing logistics costs by 20% and shortening logistics transport time to 1 / 6. It is known.

[0005] At this time, as the main decision-making of the logistics automation system, shortest path and cost information thereto are derived and used for path search or work assignment of logistics robots, etc. from a starting node to a destination node.

[0006] Therefore, as shown in FIG. 2, in a conventional logistics automation system, the entire working space is generally represented by a graph composed of nodes and edges, and the shortest path or cost information is calculated using algorithms such as the Dijkstra algorithm or the A* algorithm.

[0007] However, in such a conventional technology, there is a problem that the execution time of the algorithm increases exponentially as the number of nodes increases.

[0008] Therefore, as shown in FIG. 3, when applying an algorithm such as the Dijkstra algorithm to the logistics system in the working space 200 composed of a plurality of nodes as described above, it takes too much calculation time, increases the calculation load of the server, increases the control request-response time between the server and the logistics robot, and may also cause a problem of reducing the operation efficiency of the logistics system.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] The present invention was devised to solve the problems of the above-mentioned conventional technologies, and an object thereof is to provide a node reduction-based optimal path calculation method, apparatus, and system capable of effectively reducing the calculation time required for detecting the shortest path and the like based on a graph including a plurality of nodes corresponding to a working space in a logistics automation system.

[0010] Also, in the present invention, an object is to provide a node reduction-based optimal path calculation method, apparatus, and system that reduce the calculation load of the server, realize fast control request-response between the server and the logistics robot, and enable stable system operation.

[0011] In addition, the detailed objects of the present invention will be self-evidently grasped and understood by experts and researchers in this technical field from the following specific contents.

MEANS FOR SOLVING THE PROBLEMS

[0012] An optimal path calculation method according to one aspect of the present invention for solving the above problems is a method for calculating an optimal path from a first node to a second node based on a graph including a plurality of nodes corresponding to a work space and edges connecting between the plurality of nodes, wherein an optimal path calculation system calculates a first representative node corresponding to the first node and a second representative node corresponding to the second node from a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes, a representative node optimal path calculation step of calculating a representative node optimal path from the first representative node to the second representative node, and an optimal path calculation step of calculating an optimal path from the first node to the second node in consideration of the representative node optimal path, a distance difference (offset) from the first representative node to the first node, and a distance difference (offset) from the second representative node to the second node.

[0013] Here, in the representative node calculation step, the representative node closest to each of the plurality of nodes can be calculated as the representative node for each node.

[0014] At this time, in the representative node calculation step, the first representative node and the second representative node can be calculated using a first table including information on the correspondence relationship between the plurality of nodes and the representative nodes.

[0015] Further, in the representative node optimal path calculation step, the representative node optimal path can be calculated using a second table including information on the distances between the respective representative nodes.

[0016] At this time, in the representative node optimal path calculation step, the Dijkstra algorithm or the A* algorithm can be applied based on the second table to calculate the representative node optimal path.

[0017] Also, in the optimal path calculation stage, an optimal path from the first node to the second node can be calculated using a first table including the representative node optimal path, information on the correspondence between the plurality of nodes and the representative node, and the distance difference (offset) between the two.

[0018] Furthermore, a representative node graph construction stage may be further included for constructing a representative node graph including information on a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes in the graph.

[0019] At this time, the representative node graph may be configured to include information on the plurality of representative nodes and a plurality of representative edges connecting the plurality of representative nodes.

[0020] Also, an optimal path calculation system according to another aspect of the present invention is an optimal path calculation system that calculates an optimal path from a first node to a second node based on a graph including a plurality of nodes corresponding to a work space and edges connecting the plurality of nodes, and among the plurality of nodes, a representative node calculation unit that calculates a first representative node corresponding to the first node and a second representative node corresponding to the second node from a plurality of representative nodes including nodes connected to three or more edges, a representative node optimal path calculation unit that calculates a representative node optimal path from the first representative node to the second representative node, and an optimal path calculation unit that calculates an optimal path from the first node to the second node in consideration of the representative node optimal path, the distance difference (offset) from the first representative node to the first node, and the distance difference (offset) from the second representative node to the second node.

Advantages of the Invention

[0021] Therefore, according to an embodiment of the present invention, in the optimal path calculation method, apparatus, and system according to an embodiment of the present invention, it is possible to effectively reduce the calculation time required to detect a shortest path or the like based on a graph including a plurality of nodes corresponding to a work space in a logistics automation system.

[0022] In addition, in the optimal route calculation method, apparatus, and system according to an embodiment of the present invention, the computational load on the server is reduced, enabling fast control requests and responses between the server and the logistics robot, and enabling stable system operation.

[0023] The effects obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention pertains from the content described in this specification.

Brief Description of the Drawings

[0024] The accompanying drawings, which are included as a part of the detailed description to assist in understanding the present invention, provide embodiments of the present invention and explain the technical idea of the present invention together with the detailed description.

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0026] The present invention can be subjected to various conversions and can have various embodiments. Hereinafter, specific embodiments will be described in detail based on the accompanying drawings.

[0027] The following embodiments are provided to assist in a comprehensive understanding of the methods, apparatuses, and / or systems described in this specification. However, this is merely an example and the present invention is not limited thereto.

[0028] When describing embodiments of the present invention, if it is determined that a specific description of the known art related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted. Also, the terms described below are terms defined in consideration of the functions in the present invention, and they may vary depending on the intentions or conventions of users, operators, etc. Therefore, the definitions should be given based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and are by no means restrictive. Unless otherwise specified, expressions in the singular form include the meaning of the plural form. In this description, expressions such as "including" or "comprising" are for referring to a certain characteristic, number, step, operation, element, part thereof, or combination, and should not be construed as excluding the existence or possibility of one or more other characteristics, numbers, steps, operations, elements, part thereof, or combination other than those described.

[0029] Also, terms such as first, second, etc. may be used to describe various components, but these components are not limited by the above terms, and the above terms are used only for the purpose of distinguishing one component from another.

[0030] Hereinafter, exemplary embodiments of a node reduction-based optimal path calculation method, apparatus, and system according to an embodiment of the present invention will be described in order with reference to the accompanying drawings.

[0031] However, as shown in FIG. 2, in a conventional logistics automation system, route search and task allocation of a logistics robot and the like are performed based on a graph including a plurality of nodes corresponding to a work space and edges connecting between the plurality of nodes.

[0032] To give a more specific example, as shown in FIG. 2(a), by applying the Dijkstra algorithm or the A* algorithm or the like based on a graph including a plurality of nodes and edges configured corresponding to a work space, the shortest path from a start node (for example, node 1 in FIG. 2(a)) to a destination node (for example, node 6 in FIG. 2(a)) and the cost at that time are calculated, or as shown in FIG. 2(b), among a plurality of logistics robots, the logistics robot located at the shortest distance (for example, r 2 ) can be selected and assigned to perform the work.

[0033] More specifically, the Dijkstra algorithm can be cited as a typical shortest path search algorithm. As shown in FIG. 2(a), the shortest path between two nodes is searched for a work space in the form of a graph.

[0034] However, the time complexity of the Dijkstra algorithm is O(|V| 2 ), and the calculation time increases exponentially as the number of nodes increases.

[0035] Also, as shown in FIG. 2(b), when operating a logistics automation system, work assignments and movement commands are issued to a logistics robot based on the Dijkstra algorithm.

[0036] At this time, the Dijkstra algorithm can be used to select the logistics robot closest to the position of the transported item for work assignment.

[0037] More specifically, in FIG. 2(b), when the shortest path value from node a to node b is c(a, b), the logistics robot r having the shortest path value closest to the position s of the transported item 2 (that is, in FIG. 2(b), c(s, r 2 ) = 3) can have the work assigned to it.

[0038] However, when applying Dijkstra's algorithm or the like to a conventional logistics system as described above, the execution time of the algorithm increases exponentially with the number of nodes, resulting in a long calculation time and sometimes increasing the calculation load on the server.

[0039] More specifically, in the conventional technology, in an actual logistics system in a work space 200 composed of a plurality of nodes, the calculation time is too long, increasing the load on the server. For this reason, it may cause a problem of increasing the control request-response time between the server and the logistics robot and reducing the operation efficiency.

[0040] For example, when taking the case of having about 9,000 nodes as an example of a large-scale logistics automation system, in such a case, a considerable calculation load is required to calculate the shortest movement path for one logistics robot, and when considering N logistics robots, it may take several seconds or more of calculation time.

[0041] Moreover, since it takes several seconds or more of calculation time every time work assignment is performed, there is also a problem that the overall operation efficiency of the logistics automation system is significantly reduced.

[0042] In contrast, in the node reduction-based optimal path calculation method, apparatus, and system according to an embodiment of the present invention, by performing hierarchical conversion of a graph including a plurality of existing nodes and edges into a representative node graph so that information highly relevant to decision-making can be identified and used, the number of overall nodes can be reduced, and based on this, the calculation time can be significantly reduced by calculating the path. Also, in an actual industrial site, the calculation load on a server or the like can be reduced, enabling fast control request-response between the server and the logistics robot and enabling stable system operation.

[0043] Note that the node reduction-based optimal path calculation method, apparatus, and system according to an embodiment of the present invention can be applied to various logistics automation systems having a graph structure, and thus can have a higher influence range.

[0044] Further, FIG. 3 shows a flowchart exemplifying the optimal path calculation method according to an embodiment of the present invention.

[0045] As shown in FIG. 3, the optimal path calculation method according to an embodiment of the present invention is a method for calculating an optimal path from a first node to a second node based on a graph including a plurality of nodes corresponding to a work space 200 and edges connecting the plurality of nodes, the optimal path calculation system 120 calculating a first representative node corresponding to the first node and a second representative node corresponding to the second node from a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes (representative node calculation step (S110)), a representative node optimal path calculation step (S120) for calculating a representative node optimal path from the first representative node to the second representative node, and an optimal path calculation step (S130) for calculating the optimal path from the first node to the second node in consideration of the representative node optimal path, a distance difference (offset) from the first representative node to the first node, and a distance difference (offset) from the second representative node to the second node.

[0046] Here, in the representative node calculation step (S110), the representative node closest to the plurality of nodes can be calculated as the representative node for each node.

[0047] At this time, in the representative node calculation step (S110), the first representative node and the second representative node can be calculated using a first table including information on the correspondence relationship between the plurality of nodes and the representative nodes.

[0048] In addition, in the representative node optimal path calculation stage (S120), the representative node optimal path can be calculated using a second table including information on the distances between the respective representative nodes.

[0049] At this time, in the representative node optimal path calculation stage (S120), the representative node optimal path can be calculated by applying an algorithm such as Dijkstra's algorithm or A* algorithm based on the second table.

[0050] In addition, in the optimal path calculation stage (S130), the optimal path from the first node to the second node can be calculated using a first table including information on the correspondence between the plurality of nodes and the representative nodes and the distance difference (offset) therebetween.

[0051] At this time, in the optimal path calculation stage (S130), the shortest path from the first node to the second node can be calculated using the representative node optimal path and the first table.

[0052] Further, in the graph, a representative node graph configuration stage (not shown) for configuring a representative node graph including information on a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes may be further included.

[0053] At this time, the representative node graph may be configured to include information on the plurality of representative nodes and a plurality of representative edges connecting the plurality of representative nodes.

[0054] Thereby, in the optimal path calculation method, apparatus, and system according to an embodiment of the present invention, the calculation time for detecting a shortest path or the like based on a graph including a plurality of nodes corresponding to a work space in a logistics automation system can be effectively reduced, and further, the calculation load on the server can be reduced to implement a fast control request - response between the server and the logistics robot, enabling stable system operation.

[0055] Also, in FIG. 4, a configuration diagram of a logistics automation system 100 to which an optimal route calculation method according to an embodiment of the present invention is applied is illustrated.

[0056] As shown in FIG. 4, a logistics automation system 100 according to an embodiment of the present invention may include logistics robots (110, 110a, ···, 110n) such as a plurality of automated guided vehicles (AGVs), and an optimal route calculation system 120 configured by a server or the like to calculate an optimal route for the logistics robot 110, and a communication network 130 connecting the logistics robot 110 and the optimal route calculation system 120.

[0057] Thereby, the logistics robot 110 can receive information regarding the optimal route in the work space 200 from the optimal route calculation system 120 and move or perform work.

[0058] More specifically, in the present invention, an optimal route for a logistics robot is calculated. At this time, the logistics robot may include an automated guided vehicle (AGV) that performs work while moving along a pre-specified route, an autonomous mobile robot (AMR), an overhead hoist transport (OHT) used in a semiconductor factory, and the like. However, the present invention is not limited thereto, and other various devices that perform work such as logistics while moving along a pre-specified route may also be included.

[0059] In the following, mainly an automated guided vehicle (AGV) will be taken up for explanation, but this is merely an example, and the present invention is not limited thereto. The present invention may also be applied to various devices depending on the application to be applied.

[0060] In addition, the logistics robot 110 can move or perform work based on the information regarding the optimal route received from the optimal route calculation system 120 composed of the server or the like. However, the present invention is not necessarily limited thereto, and it may be embodied to operate in more various ways, such as moving or performing work based on data calculated by additional operations or the like based on the information received from the optimal route calculation system 120.

[0061] Here, the optimal route calculation system 120 may be composed of a server or the like. However, the present invention is not necessarily limited thereto, and depending on the operating environment, the optimal route calculation system 120 may not be embodied as a separate device, and it is also possible to be configured integrally in combination with one or two or more logistics robots 110.

[0062] Note that the communication network 130 connecting the logistics robot 110 and the optimal route calculation system 120 may include a wired network and a wireless network. Specifically, it may include various communication networks such as a local area network (LAN), a metropolitan area network (MAN), and a wide area network (WAN). In addition, the communication network 130 may include the known World Wide Web (WWW). However, the communication network 130 according to the present invention is not limited to the listed networks, and may include a known wireless data network or a known wired / wireless network.

[0063] Hereinafter, with reference to FIGS. 3 and 4, the optimal route calculation method, apparatus, and system according to an embodiment of the present invention will be described in more detail by separating each component.

[0064] At this time, in the optimal path calculation method according to an embodiment of the present invention, in the logistics automation system 100, based on a graph including a plurality of nodes corresponding to the working space 200 and edges connecting the plurality of nodes, an optimal path from a first node as a starting node to a second node as a destination node is calculated.

[0065] For this purpose, first, in the representative node calculation step (S110), the optimal path calculation system 120 calculates a first representative node corresponding to the first node and a second representative node corresponding to the second node from a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes.

[0066] Here, in the representative node calculation step (S110), it is possible to calculate the representative node closest to the plurality of nodes as the representative node for each node.

[0067] At this time, in the representative node calculation step (S110), the first representative node and the second representative node can be calculated using a first table including information on the correspondence relationship between the plurality of nodes and the representative nodes.

[0068] Thereby, in the representative node optimal path calculation step (S120), the representative node optimal path can be calculated using a second table including information on the distances between the representative nodes.

[0069] At this time, in the representative node optimal path calculation step (S120), it is possible to apply Dijkstra's algorithm based on the second table to calculate the representative node optimal path, but the present invention is not necessarily limited thereto.

[0070] Further, the optimal route calculation method according to an embodiment of the present invention may further include a representative node graph construction step (not shown) of constructing a representative node graph including information on a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes in the graph.

[0071] At this time, the representative node graph may be configured to include information on the plurality of representative nodes and a plurality of representative edges connecting the plurality of representative nodes.

[0072] More specifically, as shown in FIG. 5(a), in the conventional logistics automation system 100, usually, for reasons related to the operation and management of the logistics robot 110, nodes are generated and managed at equal intervals even at non-separation / confluence points.

[0073] However, nodes that are not at separation / confluence points as described above may cause unnecessary calculations and significantly increase the required computing resources and computing time when applying algorithms such as Dijkstra's algorithm.

[0074] In contrast, in the optimal route calculation method, apparatus, and system according to an embodiment of the present invention, as shown in FIG. 5(b), by selecting and using representative nodes, which are logical nodes based on separation / confluence points instead of all nodes, it becomes possible to effectively reduce the computing resources and computing time required for optimal route calculation.

[0075] More specifically, as shown in FIG. 6(a), in the conventional logistics automation system 100, usually, a plurality of nodes are used at equal intervals even at non-separation / confluence points, and a link table including information on the plurality of nodes and information on the connection relationship between each node is generated and used.

[0076] In contrast, in the optimal path calculation method, apparatus, and system according to an embodiment of the present invention, as shown in FIG. 6(b), based on a graph including a plurality of nodes and a plurality of edges for the work space 200, a representative node table (= second table) including information about each representative node, and an offset table (= first table) including information about the correspondence between the plurality of nodes and the representative nodes and the distance difference (offset) therebetween can be generated.

[0077] That is, as shown in FIG. 6(b), in the work space 200, all nodes can be represented by information about the representative node of the node and the distance difference (offset) from the representative node. Thus, the relationship with the corresponding representative node based on each node can be configured as an offset table (= first table).

[0078] Accordingly, in the optimal path calculation stage (S130), the optimal path from the first node to the second node is calculated in consideration of the representative node optimal path, the distance difference (offset) from the first representative node to the first node calculated from the offset table (= first table), and the distance difference (offset) from the second representative node to the second node.

[0079] At this time, the first table may include information about the correspondence between the plurality of nodes and the representative nodes and the distance difference (offset) therebetween. Thus, the optimal path from the first node to the second node is calculated using the first table, and further, the shortest path from the first node to the second node can be calculated using the representative node optimal path calculated in the representative node optimal path calculation stage (S120) and the first table.

[0080] More specifically, in FIG. 7(a), in order to calculate the shortest path from a specific first node to a second node, such as from the starting node (Origin in FIG. 7(a)) to the destination node (Destination in FIG. 7(a)), first, (1) check the representative nodes of the first node and the second node.

[0081] For this purpose, an offset table (= first table) can be used to calculate the representative nodes for the first node and the second node.

[0082] More specifically, in FIG. 7(a), when explaining the case of calculating the shortest path from node 2 (Origin) to node 26 (Destination), using the offset table (= first table) in FIG. 7(b), nodes 3 and 24 can be calculated as the representative nodes for node 2 and node 26.

[0083] Next, (2) based on a representative node table (= second table), apply Dijkstra's algorithm or the like to calculate the optimal path from the first node to the second node.

[0084] More specifically, applying Dijkstra's algorithm based on the representative node table in FIG. 7(b), as shown in FIG. 7(a), the optimal path (= representative node optimal path) between representative nodes node 3 and node 24 can be calculated.

[0085] Thereby, (3) it becomes possible to calculate the optimal path value from the first node to the second node in consideration of the calculated representative node optimal path and the offset values for the first node and the second node.

[0086] More specifically, as shown in FIG. 7(a), by summing the offset value from node 2 to node 3, the shortest path value from node 3 to node 24, and the offset value from node 24 to node 26, the shortest path value from node 2 to node 26 can be calculated.

[0087] Thus, in the optimal route calculation method, apparatus, and system according to an embodiment of the present invention, in an automated logistics system, the calculation time required to detect a shortest route or the like based on a graph including a plurality of nodes corresponding to a working space can be effectively reduced. Furthermore, the calculation load on the server can be reduced, enabling a fast control request-response between the server and the logistics robot and enabling stable system operation.

Embodiment

[0088] More specifically, as an experimental example of the present invention, when applying the optimal route calculation method, apparatus, and system according to an embodiment of the present invention to an automated logistics system based on an automated guided vehicle (AGV) having 9,088 nodes and 11,183 edges, the following is the case.

[0089] First, when directly applying Dijkstra's algorithm to a graph including the entire 9,088 nodes and 11,183 edges to calculate the shortest route between a specific first node and a second node, the calculated average time is 17.095 ms (Figure 8(a)(i) Single Pair Cost). In contrast, in the optimal route calculation method, apparatus, and system according to an embodiment of the present invention, it is understood that it takes an average of 0.001 ms (Figure 8(b)(iv) Single Pair Cost). It was confirmed that the shortest route for an individual node pair can be calculated in a very short time of 0.006% compared to the prior art.

[0090] Also, in the above experimental example, when directly applying Dijkstra's algorithm to a graph containing 9,088 nodes and 11,183 edges in total to calculate the shortest paths between all 9,088 nodes, it took a total of 8,104.1 seconds (Figure 8(a) (ii) All Pair Cost), approximately 135 minutes), while in the optimal path calculation method, apparatus, and system according to an embodiment of the present invention, it took a total of 214.5 seconds (Figure 8(b) (v) All Pair Cost), approximately 3.56 minutes), and it was confirmed that the shortest path calculation for all nodes can be performed in a shorter time of 2.647% compared to the prior art.

[0091] In addition, in the optimal path calculation method, apparatus, and system according to an embodiment of the present invention, in a graph including all nodes and edges, a representative node table including a plurality of representative nodes including nodes (i.e., nodes at branch / merge points) connected to three or more edges among a plurality of nodes in advance can be constructed.

[0092] On the other hand, in the above experimental example, for a graph including 9,088 nodes and 11,183 edges in total, in the process of identifying representative nodes and edges with a high degree of relevance to decision-making among all the nodes and edges, as a result of separately measuring the time required therefor, it was confirmed that it took 39.1 seconds to calculate 1,855 representative nodes (Figure 8(b) (iii)).

[0093] Therefore, it is also possible to calculate the shortest path for each node pair by applying Dijkstra's algorithm or the like to all nodes according to the prior art (Single Pair). However, in a complex logistics automation system 100 including a plurality of nodes, when dozens to hundreds of shortest paths need to be calculated simultaneously, excessive system load may occur and a significant delay in calculation time may occur. Moreover, when calculating the shortest paths for all nodes collectively, it may take a considerable amount of time up to several hours, making it difficult to apply in the actual field (All Pair).

[0094] On the other hand, in the optimal path calculation method, apparatus, and system according to an embodiment of the present invention, if representative nodes and the like are calculated in advance only for about several tens of seconds at the initial driving time, then the shortest paths for each pair of nodes can be calculated within a very short time thereafter, enabling efficient operation of the large-scale logistics automation system 100.

[0095] Also, FIG. 9 illustrates a configuration diagram of an optimal path calculation system 120 according to an embodiment of the present invention.

[0096] As shown in FIG. 9, an optimal path calculation system 120 according to an embodiment of the present invention is an optimal path calculation system 120 that calculates an optimal path from a first node to a second node based on a graph including a plurality of nodes corresponding to a work space 200 and edges connecting between the plurality of nodes, and may include a representative node calculation unit 121, a representative node optimal path calculation unit 122, and an optimal path calculation unit 123.

[0097] Here, more detailed content regarding the optimal path calculation system 120 according to an embodiment of the present invention can be inferred from the description of the optimal path calculation method according to an embodiment of the present invention described above with reference to FIGS. 1 to 8. In the following, the description will be centered on the core configuration, and detailed descriptions will be omitted.

[0098] More specifically, in the optimal path calculation system 120 according to an embodiment of the present invention, in the representative node calculation unit 121, among the plurality of nodes, a first representative node corresponding to the first node and a second representative node corresponding to the second node are calculated from a plurality of representative nodes including nodes connected to three or more edges.

[0099] Also, in the representative node optimal path calculation unit 122, a representative node optimal path from the first representative node to the second representative node is calculated.

[0100] Note that, in the optimal route calculation unit 123, the optimal route from the first node to the second node is calculated in consideration of the representative node optimal route, the distance difference (offset) from the first representative node to the first node, and the distance difference (offset) from the second representative node to the second node.

[0101] Thereby, in the optimal route calculation method, apparatus, and system according to an embodiment of the present invention, it is possible to effectively reduce the calculation time required to detect a shortest route or the like based on a graph including a plurality of nodes corresponding to a work space in a logistics automation system.

[0102] In addition, in the optimal route calculation method, apparatus, and system according to an embodiment of the present invention, the calculation load on the server is reduced, enabling a fast control request-response between the server and the logistics robot, and enabling stable system operation.

[0103] The above description merely exemplarily explains the technical idea of the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are not for limiting the technical idea of the present invention, but for explanation, and the present invention is not limited to such embodiments. The protection scope of the present invention should be interpreted by the appended claims, and any technical idea within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

Claims

1. A method for calculating an optimal path from a first node to a second node based on a graph including a plurality of nodes corresponding to a work space and edges connecting between the plurality of nodes, comprising: a representative node calculation step of calculating, by an optimal path calculation system, a first representative node corresponding to the first node and a second representative node corresponding to the second node from a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes; a representative node optimal path calculation step of calculating a representative node optimal path from the first representative node to the second representative node; an optimal path calculation step of calculating an optimal path from the first node to the second node in consideration of the representative node optimal path, a distance difference (offset) from the first representative node to the first node, and a distance difference (offset) from the second representative node to the second node; An optimal path calculation method characterized by including the above steps.

2. In the representative node calculation step, The optimal path calculation method according to claim 1, characterized in that a representative node closest to each of the plurality of nodes is calculated as a representative node for each node.

3. In the representative node calculation step, The optimal path calculation method according to claim 2, characterized in that the first representative node and the second representative node are calculated using a first table including information on a correspondence relationship between the plurality of nodes and the representative nodes.

4. In the representative node optimal path calculation step, The optimal path calculation method according to claim 1, characterized in that the representative node optimal path is calculated using a second table including information on distances between the representative nodes.

5. In the representative node optimal path calculation step, The optimal path calculation method according to claim 4, characterized in that the Dijkstra algorithm or the A* algorithm is applied based on the second table to calculate the representative node optimal path.

6. In the optimal path calculation step, The optimal path calculation method according to claim 1, characterized in that an optimal path from the first node to the second node is calculated using a first table including information on a correspondence relationship between the plurality of nodes and the representative nodes and a distance difference (offset) therebetween.

7. In the optimal path calculation step, The optimal route calculation method according to claim 6, characterized in that a shortest route from the first node to the second node is calculated using the representative node optimal route and the first table.

8. The optimal route calculation method according to claim 1, further comprising a representative node graph construction step of constructing a representative node graph including information on a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes in the graph.

9. The representative node graph is The optimal route calculation method according to claim 8, characterized in that it is configured to include information on the plurality of representative nodes and a plurality of representative edges connecting the plurality of representative nodes.

10. An optimal route calculation system for calculating an optimal route from a first node to a second node based on a graph including a plurality of nodes corresponding to a work space and edges connecting between the plurality of nodes, a representative node calculation unit that calculates a first representative node corresponding to the first node and a second representative node corresponding to the second node from among a plurality of representative nodes including nodes connected to three or more edges among the plurality of nodes; a representative node optimal route calculation unit that calculates a representative node optimal route from the first representative node to the second representative node; an optimal route calculation unit that calculates an optimal route from the first node to the second node in consideration of the representative node optimal route, a distance difference (offset) from the first representative node to the first node, and a distance difference (offset) from the second representative node to the second node; An optimal route calculation system, characterized by including the above.

Images