CN117217396B - A method and system for determining the existence of multi-target delivery paths based on road network - Google Patents

Abstract

The invention relates to the fields of computer science and geographic information science, and particularly discloses a multi-target dispatch path existence judging method based on a road network, which comprises the following steps: s1, obtaining a road network diagram comprising a logistics distribution area range; s2, searching nodes with the degree of 2 in the graph, and determining all parts of necessary routes in the graph; s3, screening out the necessary polygon according to the part of the necessary route; s4, eliminating unnecessary lines according to the unnecessary polygons; s5, eliminating the need of polygon; s6, if the suspension point appears, the road network does not have a multi-target dispatch path, otherwise, the road network has a multi-target dispatch path. The invention also discloses a multi-target dispatch path existence judging system based on the road network. The method and the system for judging the existence of the multi-target dispatch path based on the road network can effectively judge whether the multi-target dispatch path exists under the constraint condition of the road network, so that the design and the planning of the logistics dispatch path under the constraint condition of the road network can be facilitated.

Description

A method and system for determining the existence of multi-target delivery paths based on road network

Technical Field

The present invention relates to the fields of computer science and geographic information science, and in particular to a method and system for determining the existence of a multi-target delivery path based on a road network.

Background technique

The problem of multi-target delivery is very common in human life. It is also a classic philosophical and practical problem: "How to go". In reality, human activities are subject to constraints such as the existing road network. It is a path analysis problem under constraints. Compared with the classic multi-target arrival path problem such as the Hamiltonian path problem, it is a special case of this type of problem. It not only considers the connectivity between the target points, but also whether the connecting lines exist, which is more complex.

The Hamiltonian path problem was proposed by astronomer William Rowan Hamilton, which aims to find a path from a given starting point to a given end point in a map network with multiple cities that passes through all other cities exactly once along the way.

The Hamiltonian path problem originates from the reality of social life and is closely related to human social life. For example, in the field of tourism, we always want to design reasonable routes to achieve the goal of visiting all the dream places in one trip; in the field of logistics, we hope to reasonably allocate the delivery path of each unmanned vehicle so that the unmanned vehicle can deliver to each delivery point in turn according to the set delivery path to achieve the economic optimization and highest efficiency of logistics delivery; in the military field, we hope that the mobile force can choose the most reasonable path to reach the target point as quickly as possible, etc. These problems are all closely related to the Hamiltonian path problem.

A road network refers to a road system composed of various roads that are interconnected and interwoven into a network within a certain area. Taking the points where roads in the road network are connected as target points, it can be seen that the connections between target points in the road network are subject to constraints. Therefore, the problem of which nodes must be passed under road network conditions can be regarded as the problem of solving the Hamiltonian path under constraints.

As a land-based creature, humans mostly move along established routes for surface activities. According to incomplete statistics, the GDP loss caused by traffic problems can reach 5%. Therefore, it is of great practical significance to human society to reasonably plan and design the necessary paths for multiple target points under road network conditions. For example, when planning logistics delivery paths under road network conditions, it is necessary to plan a path that can pass through all delivery points and each delivery point only once, that is, the Hamiltonian path, so that the same delivery route will not be repeated during the logistics delivery process, making the delivery and transportation process design more reasonable, thereby improving the logistics delivery efficiency. When planning multi-target delivery paths, it is first necessary to determine whether the Hamiltonian path exists under the road network constraints. If such a multi-target delivery path does not exist under this constraint, the subsequent multi-target delivery path planning can only be futile. Therefore, it is very necessary to provide a method that can quickly search for multi-target delivery paths under road network constraints.

Summary of the invention

The present invention aims to solve at least one of the technical problems mentioned above, and provides a method and system for determining the existence of a multi-target delivery path based on a road network, which can effectively determine whether a multi-target delivery path exists under the constraints of the road network, so as to facilitate the subsequent design and planning of logistics delivery paths under the constraints of the road network.

In order to achieve the above object, the technical solution adopted by the present invention is: a method for determining the existence of a multi-target delivery path based on a road network, comprising the following steps:

S1. Obtain a road network diagram including the logistics delivery area, use the logistics delivery points as nodes in the road network diagram, and perform topological faceting on the road network diagram;

S2, search for nodes with a degree of 2 in the graph, and determine all the necessary routes in the graph through the searched nodes;

S3, filtering out the necessary polygons according to the necessary route;

S4, eliminating the routes that must not be passed according to the polygons that must be passed;

S5. Eliminate the polygons that must not be passed according to the routes that must not be passed and the routes that must be passed;

S6. If a hanging point appears after deleting the must-not-pass routes and must-not-pass polygons, there is no multi-target delivery path in the road network, otherwise there is a multi-target delivery path in the road network.

Preferably, the step S1 includes the following steps:

S11. Obtain a road network map within the logistics delivery range, and vectorize the obtained road network map;

S12, linearizing the vectorized road network to obtain linear road network data;

S13, performing line-to-surface conversion topology processing on the linear road network data. If the linear road network data has a broken line, there is no multi-target delivery path and the search is terminated. Otherwise, the process goes to step S14;

S14, perform spatial query analysis on the linear road network and the target point. If the target point intersects with the linear road network, that is, the point is on the line, proceed to step S15. If there is a hanging point, the road network graph does not have a multi-target delivery path and the search ends;

S15. Perform line topology surface construction on the graph. If a broken line appears, the road network graph does not have a multi-target delivery path and the search ends. If no broken line exists, proceed to step S2.

Preferably, in step 2, the number of connecting lines of all nodes is solved by performing point and line topology on the graph, and the number of connecting lines of the node is the degree; if the degree of the node is not 2, the connecting line connected to the node is a non-necessary route; if the degree of the node is 2, the two connecting lines connected to the node are necessary routes.

Preferably, in step 3, a necessary route located on the outermost boundary line of the graphic is searched; and a polygon whose boundary line includes the searched necessary route is determined as a necessary polygon.

Preferably, the step S4 includes the following steps:

S41, analyzing the outer boundary of the must-pass polygon to determine whether there is an adjacency to the must-pass route;

S42, if there is no must-pass route adjacency, proceed to S5, if there is a must-pass route adjacency, delete the other routes at the intersection of the two must-pass routes, and the deleted routes are the must-not-pass routes;

S43, automatically reorganize adjacent polygons according to the paths that must be deleted, and return to S41.

Preferably, in step S5, the reorganized polygon is a necessary polygon, and it is determined whether there is a necessary route between the necessary polygon and the adjacent polygons; if so, the non-necessary polygon is deleted.

Preferably, in step 6, a spatial analysis is performed on the graph filtered in steps S4 and S5; if there are hanging points, there is no multi-target delivery path in the road network; if there are no hanging points, there is a multi-target delivery path in the road network.

The present application also discloses a multi-target delivery path existence determination system based on a road network, comprising:

A data acquisition module is used to obtain a road network map including the scope of the logistics delivery area;

The data processing module is used to convert the logistics delivery points into nodes in the road network diagram and perform topological faceting on the road network diagram;

Graphics processing module; used to search for nodes with a degree of 2 in the graph, determine the parts of all the necessary routes in the graph through the searched nodes; filter out the necessary polygons according to the parts of the necessary routes; eliminate the necessary routes according to the necessary polygons; eliminate the necessary polygons according to the necessary routes and the necessary routes;

Data analysis module; used to obtain the graphics processed by the data processing module and the graphics processing module, and search whether there are hanging points or broken lines in the graphics. If there are hanging points or broken lines, there is no multi-target delivery path in the road network; if there is no hanging point, there is a multi-target delivery path in the road network.

The beneficial effect is: compared with the prior art, the method and system for determining the existence of a multi-target delivery path based on a road network of the present invention performs deep constraints on the road network diagram by determining the necessary and non-negotiable lines and polygons, and determines whether the multi-target delivery path exists under the road network constraint conditions through the singular relationships in the constraints, namely the broken lines and hanging points, thereby realizing the expanded application of logical thinking in multi-dimensional space problems, avoiding the drawbacks of a large number of redundant calculations of logical thinking, and reducing the complexity of the problem to a computational complexity level related to the number of nodes, so that it can quickly and effectively determine whether the multi-target delivery path exists under the road network constraint conditions, so as to facilitate the subsequent design and planning of the multi-target delivery path under the road network constraint conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

FIG1 is a road network diagram of a logistics delivery point in the present invention;

FIG. 2 is a schematic diagram of FIG. 1 after topological faceting.

FIG. 3 is a schematic diagram after the necessary route is searched out in FIG. 2 .

FIG. 4 is a schematic diagram showing the filtering of the necessary polygons according to the necessary routes on the outermost boundary line of the graphic.

FIG. 5 is a schematic diagram after the first peripheral search through the necessary polygons.

FIG. 6 is a schematic diagram showing the Nth peripheral search through the necessary polygons.

FIG. 7 is a schematic diagram showing the necessary polygon integration after deleting redundant paths.

FIG. 8 is a schematic diagram of FIG. 7 after the necessary polygons are screened out.

FIG. 9 is a schematic diagram after deleting the unnecessary polygons.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is referred to as being "set in the middle", it does not only mean being set in the middle, as long as it is not set at both ends within the range defined by the middle. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and/or" used herein includes any and all combinations of one or more related listed items.

The Hamiltonian cycle is the extension of a closed line in two-dimensional space, and a line is a node connection relationship, so this problem involves three-dimensional basic graphics: points, lines, and surfaces. For the Hamiltonian problem, its essence is to determine the node connection relationship, which is a logical problem, so it is a simple one-dimensional problem. The distribution space of the solution is a surface, which belongs to two dimensions (high dimension), so there are infinite possibilities for the solution of the problem.

Dimensional expansion represents infinite possibilities, but it does not mean chaos. Dimensional expansion is still constrained by basic mathematical principles. Therefore, when solving this problem, we cannot ignore these basic invisible constraints and only solve the problem through logical analysis. Looking at the relationship between points, lines and surfaces, points are the characteristic points of lines, lines are the logical connection of points, lines are the boundaries of surfaces, and surfaces are closed lines. Therefore, it can be understood that the Hamiltonian cycle is a surface, and the line problem of the Hamiltonian cycle is extended to the surface.

Since the Hamiltonian cycle involves points, lines and surfaces, the basic undirected graph can be analyzed as follows through basic constraints: the points, lines and surfaces are filtered through the Hamiltonian cycle definition and spatial constraints. If singularities of points, lines and surfaces occur, such as isolated points or lines, then the Hamiltonian cycle does not exist. Therefore, through this thinking, it is possible to determine whether the Hamiltonian cycle, that is, the multi-target delivery path, exists or not.

Therefore, the present application discloses a method for determining the existence of a multi-target delivery path based on a road network, comprising the following steps:

S1, as shown in FIG1, obtain a road network diagram including the logistics delivery area, take the logistics delivery points as nodes in the road network diagram, and then perform topological faceting on the road network diagram as shown in FIG2;

Specifically, step S1 includes the following steps:

S11. Obtain a road network map within the logistics delivery range, and vectorize the obtained road network map;

S12, linearizing the vectorized road network to obtain linear road network data;

S13, performing line-to-surface conversion topology processing on the linear road network data. If the linear road network data has a broken line, there is no multi-target delivery path and the search is terminated. Otherwise, the process goes to step S14;

S14, perform spatial query analysis on the linear road network and the target point. If the target point intersects the linear road network, that is, the point is on the line, then enter step S15. If there is a hanging point, the road network diagram does not have a multi-target delivery path and the search ends. In order to facilitate subsequent processing, in this step, when the target point is not at a node of the road network, the target point can be processed using the adjacent point principle, that is, if the adjacent point a is located on the line bc between the two nodes b and c, if the distance ab is less than the distance ac, the node b is used as the target point a for subsequent processing;

S15, perform line topology faceting on the graph. If a broken line appears, the road network graph does not have a multi-target delivery path and the search ends. If no broken line exists, proceed to step S2;

S2. As shown in FIG3 , search for nodes with a degree of 2 in the graph, and determine the part of all necessary routes in the graph through the searched nodes, wherein the routes marked in bold in FIG3 are the necessary routes found out, and the number of node connection lines is the degree. If the degree of the node is not 2, the connection line connected to the node is a non-necessary route; if the degree of the node is 2, the two connection lines connected to the node are necessary routes;

S3, as shown in FIG4, according to the part of the necessary route, the necessary polygon is screened out. Preferably, when screening, the necessary route located on the outermost boundary line of the figure can be searched; the polygon including the necessary route located on the outermost edge of the figure is determined as the necessary polygon, and the searched necessary polygon is the polygon in the black part in FIG4;

S4, according to the must-pass polygon, eliminate the must-not-pass route. Specifically, the outer boundary of the must-pass polygon can be analyzed to determine whether there is a must-pass route adjacency situation. If there is no must-pass route adjacency situation, enter S5. If there is a must-pass route adjacency situation, delete the other routes at the intersection of the two must-pass routes. The deleted route is the must-not-pass route, as shown in Figure 7. Then, according to the deleted must-not-pass path, the adjacent polygons are automatically reorganized. Repeat the above steps, as shown in Figures 5 and 6, until all the polygons that can be reorganized are reorganized;

S5, as shown in FIG8 , according to the unnecessary routes and the necessary routes, the unnecessary polygons are eliminated, wherein the reorganized polygons are the necessary polygons, and it is determined whether there is a necessary route between the necessary polygons and the adjacent polygons; if so, the non-necessary polygons are deleted;

S6. As shown in Figure 9, if hanging points appear after deleting the must-not-pass lines and must-not-pass polygons, there is no multi-target delivery path in the road network, otherwise there is a multi-target delivery path in the road network, wherein the graphics filtered by steps S4 and S5 can also be spatially analyzed; if there are hanging points, there is no multi-target delivery path in the road network; if there are no hanging points, there is a multi-target delivery path in the road network.

A method for determining the existence of a multi-target delivery path based on a road network of the present invention performs deep constraints on a road network diagram by determining necessary and non-negotiable routes and polygons, and determines whether a multi-target delivery path exists under the road network constraint conditions through singular relationships in the constraints, namely, broken lines and hanging points. This realizes the expanded application of logical thinking in multi-dimensional space problems, avoids the drawbacks of a large number of redundant calculations of logical thinking, and reduces the complexity of the problem to a computational complexity level related to the number of nodes, thereby being able to quickly and effectively determine whether a multi-target delivery path exists under the road network constraint conditions, so as to facilitate the subsequent design and planning of multi-target delivery paths under the road network constraint conditions.

In addition, the present application also discloses a multi-target delivery path existence determination system based on a road network, including a data acquisition module, a data processing module, a graphics processing module and a data analysis module, wherein the data acquisition module is used to obtain a road network map including a logistics delivery area; the data processing module is used to convert logistics delivery points into nodes in the road network map, and perform topological surface construction on the road network map; the graphics processing module is used to search for nodes with a degree of 2 in the graph, and determine the part of all necessary routes in the graph through the searched nodes; according to the part of the necessary routes, filter out necessary polygons; according to the necessary polygons, eliminate the necessary routes; according to the necessary routes and the necessary routes, eliminate the necessary polygons; the data analysis module is used to obtain the graphics processed by the data processing module and the graphics processing module, and search whether there are hanging points or broken lines in the graphics. If there are hanging points or broken lines, there is no multi-target delivery path in the road network; if there is no hanging point, there is a multi-target delivery path in the road network.

A multi-target delivery path existence determination system based on a road network of the present invention performs deep constraints on a road network diagram by determining necessary and non-negotiable routes and polygons, and determines whether a multi-target delivery path exists under the road network constraint conditions through singular relationships in the constraints, namely, broken lines and hanging points. This realizes the expanded application of logical thinking in multi-dimensional space problems, avoids the drawbacks of a large number of redundant calculations of logical thinking, and reduces the complexity of the problem to a computational complexity level related to the number of nodes, thereby being able to quickly and effectively determine whether a multi-target delivery path exists under the road network constraint conditions, so as to facilitate the subsequent design and planning of multi-target delivery paths under the road network constraint conditions.

The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Any modification or equivalent substitution that does not depart from the spirit and scope of the present invention shall be included in the scope of the technical solution of the present invention.

Claims (4)

1. A method for determining the existence of a multi-target delivery path based on a road network, characterized in that it comprises the following steps: S1. Obtain a road network diagram including the logistics delivery area, use the logistics delivery points as nodes in the road network diagram, and perform topological faceting on the road network diagram, which includes the following steps: S11. Obtain a road network map within the logistics delivery range, and vectorize the obtained road network map; S12, linearizing the vectorized road network to obtain linear road network data; S13, performing line-to-surface conversion topology processing on the linear road network data. If the linear road network data has a broken line, there is no multi-target delivery path and the search is terminated. Otherwise, the process goes to step S14; S14, perform spatial query analysis on the linear road network and the target point. If the target point intersects with the linear road network, that is, the point is on the line, proceed to step S15. If there is a hanging point, the road network graph does not have a multi-target delivery path and the search ends; S15, perform line topology faceting on the graph. If a broken line appears, the road network graph does not have a multi-target delivery path and the search ends. If no broken line exists, proceed to step S2; S2, search for nodes with a degree of 2 in the graph, and determine all the necessary routes in the graph through the searched nodes; S3, according to the part of the necessary route, filter out the necessary polygons, when filtering, search for the necessary route located on the outermost boundary line of the figure, and determine that the polygon including the necessary route located on the outermost edge of the figure is the necessary polygon; S4, according to the must-pass polygon, eliminate the must-not-pass route, analyze the outer boundary of the must-pass polygon, and determine whether there is a must-pass route adjacency situation. If there is no must-pass route adjacency situation, enter S5, if there is a must-pass route adjacency situation, delete the other routes at the intersection of the two must-pass routes, and the deleted routes are the must-not-pass routes. Then, according to the deleted must-not-pass paths, automatically reorganize the adjacent polygons, and repeat the above steps until all the polygons that can be reorganized are reorganized; S5. Eliminate the non-necessary polygons according to the non-necessary routes and the necessary routes. The reorganized polygons are the necessary polygons. It is determined whether there is a necessary route between the necessary polygons and the adjacent polygons. If so, delete the non-necessary polygons. S6. If a hanging point appears after deleting the must-not-pass routes and must-not-pass polygons, there is no multi-target delivery path in the road network, otherwise there is a multi-target delivery path in the road network. 2. According to claim 1, a method for determining the existence of a multi-target delivery path based on a road network is characterized in that in step 2, the number of connecting lines of all nodes is solved by performing point and line topology on the graph, and the number of connecting lines of the node is the degree; if the degree of the node is not 2, the connecting line connected to the node is a non-necessary route; if the degree of the node is 2, the two connecting lines connected to the node are necessary routes. 3. According to the method for determining the existence of a multi-target delivery path based on a road network as described in claim 1, it is characterized in that in step 6, a spatial analysis is performed on the graphics filtered by steps S4 and S5; if there are hanging points, there is no multi-target delivery path in the road network; if there are no hanging points, there is a multi-target delivery path in the road network. 4. A multi-target delivery path existence determination system based on a road network, characterized by comprising: A data acquisition module is used to obtain a road network map including the scope of the logistics delivery area; The data processing module is used to convert the logistics delivery points into nodes in the road network diagram and perform topological faceting on the road network diagram; Graphics processing module; used to search for nodes with a degree of 2 in the graph, and determine the parts of all necessary routes in the graph through the searched nodes; according to the parts of the necessary routes, screen out the necessary polygons, and according to the parts of the necessary routes, screen out the necessary polygons. When screening, search for the necessary routes located on the outermost boundary line of the graph, and determine that the polygons including the necessary routes located on the outermost boundary of the graph are necessary polygons; according to the necessary polygons, eliminate the necessary non-passage routes, analyze the outer boundaries in the necessary polygons, and determine whether there is a necessary route adjacency situation. If there is no necessary route adjacency situation, proceed to the next step. If there is a necessary route adjacency situation, delete the other routes at the intersection of the two necessary routes, and the deleted routes are necessary non-passage routes. Then, according to the deletion of the necessary non-passage paths, automatically reorganize the adjacent polygons, and repeat the above steps until all the polygons that can be reorganized are reorganized; according to the necessary non-passage routes and the necessary routes, eliminate the necessary non-passage polygons, and the reorganized polygons are necessary polygons. Determine whether there is a necessary route between the necessary polygon and the adjacent polygon; if so, delete the non-necessary polygons; Data analysis module; used to obtain the graphics processed by the data processing module and the graphics processing module, and search whether there are hanging points or broken lines in the graphics. If there are hanging points or broken lines, the multi-target delivery path does not exist, and specific targets need to be delivered separately; if there are no hanging points, the multi-target delivery path exists.