JP2018031947A - Map creation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that can properly prepare maps.SOLUTION: A map creation device comprises: a storage unit that stores network data having information about attributes of features corresponding to advancible linear features in a plurality of directions via a branch point; and a control unit that creates a shape of the feature corresponding to the specific attribute as shape information which is a shape abbreviated to a specific shape on the basis of the network data, and creates a map having the shape information. In Fig. 20, the map creation device is configured to create a characteristic shape composed of a link L200, link L110, and link L220 with a node N200, node N10, and node N5 as end points.SELECTED DRAWING: Figure 20

Description

  The present invention relates to a map creation device.

In a car navigation system, a pedestrian navigation system, a tourist map, and the like, generally, a schematic map with high visibility in which a shape of a road or the like is simplified is displayed.
Conventionally, the rough map creation method is not only a method of deforming roads by realizing road straightening and direction quantization, but also extracting features from maps and simplifying them using approximate figures. A method (for example, Patent Document 1) is disclosed.

  The technique disclosed in Patent Document 1 will be specifically described.

  In Patent Document 1, a closed figure is extracted as a feature part from a map, a geometric figure closest to the feature part is determined as an approximate figure, and a feature part is considered in consideration of a correlated feature or similarity between a plurality of feature parts. An approximate map creation method is disclosed in which the global features of a map are maintained by moving and transforming the map.

JP 2010-128084 A

  An object of the present invention is to provide a technique for appropriately creating a map.

  As one embodiment of the present invention, a storage unit that stores network data having information on attributes of the feature corresponding to a linear feature that can travel in a plurality of directions via a branch point, and the network A schematic map creation device comprising: a control unit that generates, based on data, the shape of the feature corresponding to a specific attribute as shape information of a shape simplified to a specific shape, and generates a map having the shape information provide.

  Note that the above-described features do not enumerate all the features of the present invention, and a configuration (or method) including these as main parts can also be an invention.

It is explanatory drawing which shows schematic structure of the map creation apparatus as one Embodiment of this invention. It is a figure explaining the content of the database stored in the memory | storage part. It is a flowchart corresponding to the whole process of a map creation apparatus. It is a flowchart corresponding to a simple area | region setting process. It is a flowchart corresponding to a route segment extraction process. It is a flowchart corresponding to a feature shape classification process. It is a flowchart corresponding to simplification processing. It is a flowchart corresponding to the search process between segments SG. It is a figure explaining the example of the linearization process. It is a figure explaining the example of direction quantization. It is a figure explaining the example of length preservation | save. It is a figure explaining the example of the triangular sample figure. It is a figure for demonstrating a route segment extraction process. It is a figure for demonstrating a route segment extraction process. It is a figure which shows the example which comprises a closed figure about the simplification area | region M1. It is a figure which shows the example which does not comprise a closed figure about the simplification area | region M2. It is a figure explaining the search process between segments SG. It is a figure which displays as a list the result of the search process between segments SG. It is a figure explaining the simplification step 1 of a feature shape. It is a figure explaining the simplification step 2 of a feature shape. It is a figure explaining the step of simplification of a feature shape. It is a figure explaining the simplification method of a non-characteristic shape.

Hereinafter, embodiments embodying the present invention will be described.
Embodiment As shown in FIG. 1, the present embodiment includes a server system 1000, a base station BS, and a display terminal 200. The server system 1000 has at least the map server 100. The map server 100 and the base station BS are communicably connected via the Internet INT. The display terminal 200 can wirelessly communicate with the base station BS. As a result, the display terminal 200 can communicate with the map server 100 via the base station BS.

  The display terminal 200 includes a current location detection unit 211, a display panel 212, an audio output unit 213, an input unit 214, a communication unit 215, an external storage device 216, and a main control unit 210. The display terminal 200 in the present embodiment is a portable smartphone.

  The current location detection unit 211 is a device that receives radio waves transmitted from artificial satellites that constitute a GPS (Global Positioning System / Global Positioning System). The display panel 212 includes a liquid crystal display and a drive circuit that drives the liquid crystal display. The audio output unit 213 includes a speaker for outputting audio, a circuit for driving the speaker, and the like. The input unit 214 includes a group of keys such as a direction input key displayed on the display panel 212 and other operation keys.

  The communication unit 215 is a circuit for performing data communication with the base station BS. The communication unit 215 can access the map server 100 via the base station BS. The external storage device 216 configured by a hard disk, a flash memory, a memory card, and the like stores various software and data for operating the display terminal 200. The external storage device 216 may be configured such that a user of the display terminal 200 can arbitrarily store various data. The main control unit 210 is a controller for controlling the above-described units 211 to 216 of the display terminal 200. The main control unit 210 includes a CPU (not shown) and an internal storage device such as a ROM and a RAM.

  The map server 100 includes a communication unit 102, a storage unit 104, and a control unit 110. The storage unit 104 includes a map database (DB) 105, a route database (DB) 106, a facility database (DB) 107, and a traffic information database (DB) 108. The traffic information database stores traffic jam information stored via the Internet INT. The traffic jam information is stored in the NW attribute information of the link LK in the route database 106 as traffic volume information, for example. The communication unit 102 can communicate with the display terminal 200 via the Internet INT and the base station BS. Details of the map database 105 will be described later.

FIG. 2 is a diagram schematically showing a database stored in the storage unit 104.
The map database 105 stores data representing a map image (map image data) in a vector data format. The map image data may be stored in a raster data format such as a bitmap format or a JPEG data format instead of the vector data format. This map image data includes data representing the shape of terrain such as rivers and ponds, buildings, roads, pedestrian roads, routes representing railway tracks, and parks.

  The route database 106 stores route data related to routes through which cars and pedestrians can pass among various routes existing in the area corresponding to the map image represented by the map image data. This route data includes network data indicating the arrangement of the route on the ground surface, and NW attribute information associated with the network data. The network data includes road network data indicating the route of the vehicle and pedestrian network data indicating the route of the pedestrian. The network data includes node data representing element points ND (hereinafter also referred to as “nodes”) in the route and link data representing line segments LK (hereinafter also referred to as “links”) connecting the nodes. The node ND represents, for example, an intersection, a T-junction, a branch point, a start point, an end point, and the like. The link LK represents a route such as the above-described roadway or pedestrian road. The NW attribute information is information that is associated with the node ND or the link LK and represents the attribute. As shown in FIG. 2, the NW attribute information includes, for example, link LK attributes (for example, traffic volume, road name, road width, number of lanes, speed limit, presence / absence of sidewalk, opening time, presence / absence of bicycle lane, person Text data Z11 including node ND attributes (for example, intersection name, link connection information, position coordinates, etc.). The NW level is an index preferentially searched in the route search in the road network data, and is usually indicated by a value such as 1 to 5. There may be one or more NW attribute information associated with one node ND or link LK. Note that the route database is not limited to a road, and may be network data having information on attributes of a feature corresponding to a linear feature that can travel in a plurality of directions via a branch point. For example, in addition to roads, network data may be associated with linear features that can travel in a plurality of directions via branch points such as rivers and routes.

  The facility database 107 stores facility data representing facility information including the name and position of the facility. The facility database 107 includes a facility point BP that indicates the location of the facility, a facility name Z21 that exists at a location that represents the facility point BP, and the like. Further, the facility information associated with one facility point BP may be one or plural.

  The control unit 110 corresponds to a linear feature that can travel in a plurality of directions via a branch point, and based on network data that has information on the attribute of the feature, A shape is generated as shape information simplified to a specific shape, and a map having the shape information is generated. Specifically, a region setting unit 111, a route segment extraction unit 112, and a feature shape are generated. A classification unit 113, a simplification unit 114, and an evaluation unit 115 are included. The region setting unit 111, the route segment extraction unit 112, the feature shape classification unit 113, the simplification unit 114, the evaluation unit 115, and the map generation unit 116 read out a control program stored in a ROM (Read Only Memory), (Random Access Memory) is a function that is executed by a CPU (Central Processing Unit), and its control program is stored in a computer (CPU) by an area setting unit 111, a route segment extraction unit 112, and a feature shape classification unit. 113 is a program for realizing functions as the simplification unit 114, the evaluation unit 115, and the map generation unit 116.

  The area setting unit 111 performs a process of setting a map range to be simplified among the map data stored in the storage unit 104. In this embodiment, the area setting unit 111 receives information related to the display screen of the display terminal 200, the user's current position information, and the scale information set by the user from the display terminal 200, and simplification centered on the user's current position. Set the map range. Although the scale information is set by the user, the area setting unit 111 may adopt a predetermined scale or a scale displayed on the display terminal 200 as the scale information.

  The route segment extraction unit 112 extracts network data existing in the range set by the region setting unit 111 and performs segmentation at a predetermined angle. In the present embodiment, the route segment extraction unit 112 extracts road network data having an NW level equal to or higher than a predetermined value from the road network data. The segmentation process refers to associating segments that are connected within a predetermined angle range in the extracted road network data as one segment. In the present embodiment, the predetermined angle range is a range in which the connection angle between the links is 160 degrees to 180 degrees, and a road road is set as one segment. The link segment processing may be extracted using NW attribute information. For example, the route segment extraction unit 112 may extract road network data based on traffic volume, road name, road width, number of lanes, speed limit, presence / absence of a sidewalk, opening time, and the like.

  The path segment extraction unit 112 refers to the NW attribute information of the segment of interest and other segments, identifies other segments having the same node ND as the node ND of the segment of interest, and combines them into the storage unit 104 The process to memorize is executed. The path segment extraction unit 112 repeats this process and performs the process on all the extracted segments.

  The feature shape classifying unit 113 determines whether or not the segment stored as a combination in the storage unit 104 by the path segment extracting unit 112 includes a closed graphic. If it is determined that the segment includes a closed graphic, the feature shape classifying unit 113 configures the closed graphic. The segment to be classified is classified as a feature shape, and the segment that does not constitute a closed figure is classified as a non-feature shape. On the other hand, if it is determined that the closed shape is not included, the feature shape classifying unit 113 performs a process of searching for a route between the segments and generating a closed shape with the searched route and the segment. When the closed figure is generated, the feature shape classification unit 113 classifies the feature shape and the non-feature shape.

  In the route search process between segments, the feature shape classifying unit 113 specifies an intersection on the segment where the area of the closed figure is maximum, and performs a route search using the intersection as an end point. The feature shape classification unit 113 refers to the NW attribute information and searches for a road with a high NW level preferentially. The feature shape classifying unit 113 generates a closed figure by performing a route search, but the NW level setting of the route segment extracting unit 112 may be set to 3 or more to expand the range of road network data extraction. The feature classification unit 113 may extract road network data based on attribute information such as a route with a large amount of traffic or a route with a sidewalk in a route search process between segments.

  The simplification unit 114 simplifies the feature shape and the non-feature shape step by step, and joins them at each simplified step. As a simplification of the feature shape, the simplification unit 114 compares the geometric shape such as a circle, an ellipse, and an n-gon with the feature shape prepared in advance, identifies the geometric shape closest to the closed figure, and identifies the identified geometric shape. A fixed deformation method that simplifies the feature shape step by step and a line segment straightening method that fixes the end points of the feature shape and straightens the line segments between the end points.

  A simplified method using the standard deformation method will be described. The simplified unit 114 specifies a geometric shape such as a circle, an ellipse, or an n-gon from the feature shape. The simplification unit 114 selects a more detailed sample shape from the identified geometric shape, and simplifies the specific shape step by step so as to approximate the selected sample shape. When the geometric shape selected by the simplification unit 114 is, for example, a triangle, the simplification unit 114 uses any one of regular triangles, right-angled isosceles triangles, isosceles triangles, and right-angle triangles as a standard geometric shape. Select a geometric shape and perform deformation processing.

  FIG. 12 shows an example of a sample figure when the geometric shape specified by the simplification unit 114 is a triangle. 12A is an equilateral triangle as a sample figure, FIG. 12B is an isosceles triangle as a sample figure, FIG. 12C is a right isosceles triangle as a sample figure, and FIG. 12D is a right triangle as a sample figure. It is shown. The simplification unit 114 selects the geometric shape closest to the feature shape from the sample shapes. Note that an evaluation score used by an evaluation unit 115 described later is associated with the sample shape. In this embodiment, high evaluation points are assigned to simple figures that are easy for the user to visually recognize, (a) 100 regular triangles, (b) 90 isosceles triangles, (c) right isosceles triangles and ( d) The right triangle has 70 points. In addition, an evaluation score may be attached | subjected not only in said reference | standard but various standards.

  When the feature shape is deformed by the standard deformation method, the simplification unit 114 arranges the feature shape after simplification based on the center of the feature shape before simplification. Note that the simplified portion 114 may arrange a simplified characteristic shape based on the outer center or the center of gravity. The simplification unit 114 stores the simplification method selected in the modification of the feature shape in the storage unit 104.

  A simplified method using a linearization method will be described. The simplification unit 114 simplifies the feature shape by fixing the end points of the feature shape and linearizing the line segment between the end points. The straightening method may be used as a simplified method different from the standard deformation method, or may be used when the feature shape does not correspond to any of the geometric shapes prepared in advance in the standard deformation method. Further, after simplification by a linearization method, a sample shape may be selected by using a standard deformation method.

  As a simplification of the non-feature shape, the simplification unit 114 performs a linearization process for linearly deforming the shape of the road group of the segments constituting the non-feature shape, and quantizes the direction of the linearly deformed road group. Direction quantization processing is performed to align the direction units, and length preservation processing is performed to match the length of the deformed road with the length of the road before the deformation. For the simplification of the non-feature shape, a simplification method according to the degree of simplification is defined, and the simplification unit 114 deforms the non-feature shape using the following simplification method.

  In the present embodiment, the non-feature shape simplification processing is performed in the order of linearization processing, direction quantization, and length preservation. FIG. 9 is a diagram illustrating an example of linearization processing. FIG. 9A shows the segment SG1 before linearization and the main axis L1 of the segment SG1. The segment SG1 includes a node ND1-link LK1-node ND2-link LK2-node ND3. The main axis line segment L1 is calculated by the least square method of each component point of the segment SG1 by the simplification unit 114. Next, as shown in FIG. 9B, the simplification unit 114 linearizes the segment SG1 by moving each node ND vertically to the main axis L1.

  FIG. 10 is a diagram illustrating an example of direction quantization. FIG. 10A shows directions D1 to D8 based on the segment SG1 and the node ND1 after the straightening process, and the segment SG1 is located between the direction D2 and the direction D3. The simplification unit 114 calculates the angle between the segment SG1 and the direction D2 and the angle between the segment SG1 and the direction D3 with the node ND1 as a base point, and moves the node ND4 in the direction of the smaller angle. In FIG. 10B, since the angle between the segment 1 and the direction D3 is smaller, the simplification unit 114 moves the node ND4 of the segment SG1 in the direction D.

FIG. 11 illustrates an example of length storage. FIG. 11A shows the length R1 of the segment SG1 after the linearization process. The length R1 is equal to the distance from the nodes ND1 to ND3. In the length saving process, as shown in FIG. 11B, the simplification unit 114 calculates the distance between the node ND1-node ND2-node ND3. The simplified unit 114 extends the segment SG1 to the length R2 based on the calculated distance.
The simplification unit 114 proceeds with the simplification of these non-feature shapes step by step, either alone or in combination.

  The simplification unit 114 connects the simplified feature shape and non-feature shape for each stage based on the link connection information of each end point (node ND). Specifically, based on the link connection information of the deformed feature shape node ND, the simplification unit 114 translates the non-feature shape and connects it to the feature shape.

  The evaluation unit 115 determines whether or not there is a contradiction in the phase relationship between the joined feature shape and the non-feature shape, and if there is no contradiction, evaluation of simplification of the feature shape and simplification of the non-feature shape for each stage. A point is calculated and stored in the storage unit 104. The evaluation unit 115 evaluates how close the feature shape and the non-feature shape are to the geometric shape. The evaluation unit 115 does not store the simplification method in the storage unit 104 when there is a contradiction in the phase relationship.

  The evaluation unit 115 refers to the evaluation point of the sample graphic selected by the simplification unit 114 in the feature shape. In the non-feature shape, the evaluation points are set according to the degree of approach to the geometric shape as a result of the linearization, direction quantization, and length preservation processes. The evaluation unit 115 calculates the total evaluation score by adding the evaluation points of the feature shape and the evaluation points of the non-feature shape. The evaluation unit 115 stores the combination of simplified methods having the highest total evaluation score in the storage unit 104.

The map generation unit 116 creates an approximate map by referring to the combination of the simplified methods having the highest total evaluation score stored in the storage unit 104, the facility database 107, the route database 106, and the map database 105. The map generation unit 116 arranges the facility point BP, the facility name Z21, etc. in the simplified network data shape based on the referenced simplification method, and creates a schematic map. The arrangement of the facility point BP and the facility name Z21 may be arranged based on the position information of the facility point BP and the facility name Z21, or may be arranged manually by an operator. The schematic map created by the map generation unit 116 is transmitted to the display terminal 200 by the communication unit 102 via the Internet INT and displayed on the display panel 212.
<Description of operation>

Next, the operation will be described.
FIG. 3 is a flowchart for explaining an outline of processing related to the schematic map generation device of this embodiment.
The control unit 110 performs a simplified area setting process (step S300) for setting an area on a map for generating a rough map, a route segment extracting process for extracting a road network in the simplified area as a segment, and storing a combination of segments ( Step S400), a feature shape classification process (Step S500) for classifying a segment forming a closed figure as a feature shape, and a segment connecting to an end point of the feature shape as a non-feature shape, and simplifying and evaluating the feature shape and the non-feature shape Simplification processing (step S600) is performed. Details of each process will be described below.

The simple area setting process will be described with reference to the flowchart of FIG.
In the simplified area setting process (step S300), the area setting unit 111 first performs a process of inputting the position information of the display terminal 200 received by the communication unit 102 (step S310). The position information of the display terminal 200 is information on the current location of the display terminal 200 detected by the current location detection unit 211. Note that the position information of the display terminal may be arbitrary position information input by the input unit 214. These pieces of position information are transmitted to the communication unit 102 of the map server 100 via the Internet INT by the communication unit 215.

  Next, the area setting unit 111 performs a process of inputting the scale value received by the communication unit 102 (step S320). The scale value is a value representing the scale of the map input by the input unit 214 of the display terminal 200. The scale value may be arbitrarily input by the user of the display terminal 200, or a predetermined value may be input in advance according to the current location. These scale values are transmitted by the communication unit 215 to the communication unit 102 of the map server 100 via the Internet INT.

  Next, the region setting unit 111 performs a process of determining a region to be simplified on the map based on the input position information and scale value (step S330). The region setting unit 111 determines the display region of the display panel 212 of the display terminal 200 as a region to be simplified from the received position information and scale value. Note that the region setting unit 111 may determine a region that is simplified by a predetermined region larger than the display region of the display panel 212, or if the route guidance is being performed, the region in the traveling direction is determined as a region that is simplified greatly. Also good.

Next, the route segment extraction process (step S400) will be described with reference to the flowchart of FIG.
In the route segment extraction process, the route segment extraction unit 112 performs a process of extracting predetermined road network data existing in the map range set by the region setting unit 111 (step S410). The predetermined road network data is, for example, a link with a high road NW level searched preferentially in route search. For example, links indicating major roads such as national roads and prefectural roads may be extracted from the predetermined road network data based on the road type, or links with a large amount of traffic may be extracted based on the traffic volume. That is, a link can be extracted according to the theme of the approximate map.

  FIG. 13 is a diagram for explaining route segment extraction processing. A region (M1) to be simplified is set by the region setting unit 111. A line segment in the area M1 is a road network, and is composed of links L1 to L15 and nodes N1 to N10. The road network displayed in FIG. 13 is a predetermined road network in the area M1 extracted by the area setting unit 111.

  Next, the route segment extraction unit 112 performs a process of segmenting the extracted road network data at a predetermined angle (step S420). In the segmenting process, the path segment extraction unit 112 associates links to be linked within a predetermined angle range as one segment from the link connection information extracted in step S410. Thus, in the present embodiment, the segment represents a link group connected on a substantially straight line.

  As shown in FIG. 14, the path segment extraction unit 112 associates the link L1, the link L2, and the link L3 connected within a predetermined angle range as a segment SG1, and links the link L8, the link L7, the link L9, the link L10, and the link L15 to the segment. Associating as SG2, associating link L11, link L16, link L5, link L6 and link L8 as segment SG3, associating link L4, link L12, link L13 and link L14 as segment SG4.

  Next, the path segment extraction unit 112 performs a process of determining a target segment SG to be processed among the segments SG1 to SG4 segmented in step S420 (step S430). Next, the path segment extraction unit 112 performs a process of determining whether the segment of interest SG intersects with another segment SG (step S440). Specifically, the route segment extraction unit 112 identifies the node of the segment of interest SG, and determines whether or not a common node that is the same node is included in other segments SG. If there is no common node between the segment of interest SG and another segment SG (No in step S440), the path segment extraction unit 112 proceeds to step S460 and determines whether all the segments SG have been processed. On the other hand, when there is a common node between the segment of interest SG and the other segments SG (Yes in step S440), the route segment extractor 112 determines that the segment of interest segment SG is combined with the other segments SG. Is stored in the storage unit 104 (step S450).

  In FIG. 14, for example, when the path segment extraction unit 112 determines the segment SG1 as a target segment (step S430), the node N1 and the node N2 of the segment SG1 are included in the segment SG2, the segment SG3, and the segment SG4, which are other segments. It is determined whether it is not (step S440). Since the route segment extraction unit 112 refers to the nodes of other segments and the node of the link SG1 and the common node are not included (No in step S440), the route segment extraction unit 112 proceeds to step S460, and all the segments It is determined whether or not has been processed. In FIG. 14, since segment SG2, segment SG3, and segment SG4 are unprocessed, the process proceeds to step S430.

  The route segment extraction unit 112 determines the segment SG2 that is the next target segment (step S430). The path segment extraction unit 112 determines whether the node N6, the node N5, the node N7, and the node N10 of the segment of interest SG2 are not included in the other segments, the segment SG1, the segment SG3, and the segment SG4 (step S440). In the case of FIG. 14, the path segment extraction unit 112 determines that the node N5 is included in the segment SG4 and the node N10 is included in the segment SG4 (Yes in step S440). The path segment extraction unit 112 associates the segment SG2, the segment SG3, and the segment SG4 and stores them in the storage unit 104 (step S450).

  In the process of step S450, the combination of the segment of interest and other segments is not limited to one-to-one and may be one-to-many. In addition, when there is an identical link in a combination of one segment and another segment, the path segment extraction unit 112 further associates them and stores them in the storage unit 104. In FIG. 14, the combination with segment SG2 is segment SG3 and segment SG4.

  Next, the path segment extraction unit 112 determines whether all the segments have been processed (step S460). If all the segments have been processed as the segment of interest (Yes in step S460), the process ends. In FIG. 14, when segment SG1 to segment SG4 are determined as the target segment, the path segment extraction unit 112 ends the process. In step S450, the route segment extraction unit 112 does not store overlapping segment combinations.

Next, the feature shape classification process will be described with reference to the flowcharts of FIGS.
In the feature shape classification process, it is determined whether or not the combination of segments stored by the route segment extraction unit 112 constitutes a closed figure. If not, a route search is performed to form a closed figure. A process of classifying a graphic into a feature shape and classifying a portion that does not constitute a closed graphic into a non-feature shape is performed. Details are described below.

  The feature shape classifying unit 113 refers to the combination of segments stored in the storage unit 104 and performs a process of determining whether or not the combination of segments constitutes a closed figure (step S510). The feature shape classifying unit 113 performs a route search using a certain common node in the segment combination as a departure point, and determines that the combination of segments constitutes a closed figure if the search branch returns to the common node at the departure point (step Yes in S510), the process proceeds to step S530. On the other hand, the feature shape classification unit 113 performs a route search using a certain common node as a departure point in the combination of segments, and determines that the combination of segments does not form a closed figure unless the search branch returns to the common node at the departure point. (No in step S510), the process proceeds to step S520.

  In FIG. 14, the feature shape classifying unit 113 performs a route search from, for example, the node N5 that is a common node of the segment SG2, the segment SG3, and the segment SG4 that is a combination of segments. In the case where the node N5 is a departure point, the node N5-node N7-node N10-node N9-node N3-node N4-node N5 or node N5-node N4-node N3-node N9-node N10-node N7-node N5 You can search the route back to the departure point. That is, the links L9-L10-L13-L12-L5-L6, which are this route, constitute a closed figure, and in this case, the feature shape classification unit 113 determines that a closed figure is constituted in step S510 (in step S510). Yes).

  Next, if the feature shape classifying unit 113 determines in step S510 that a closed figure is to be formed (Yes in step S510), the combination of segments is classified into a feature shape that forms the closed figure and a non-feature shape that is connected to the closed figure. Processing is performed (step S530). The feature shape classification process ends in step S530.

  FIG. 15 is a diagram illustrating that the feature shape classification unit 113 classifies the feature shape and the non-feature shape with respect to the simplified region M1. A closed figure (L5-L6-L9-L10-L13-L12) represented by a thick line in FIG. 15 is a characteristic shape. The segment connected to this feature shape becomes a non-feature shape. In the case of FIG. 15, the links L7-L8, the link L17, the link L15, the link L4, the link L14, the link L15, the link L11, and the link L16 are classified as non-feature shapes. The

  On the other hand, if it is determined in step S510 that the combination of segments does not constitute a closed figure (No in step S510), the feature shape classifying unit 113 performs processing for searching between the segments SG (step S520). FIG. 16 illustrates an example in which it is determined that the combination of segments does not form a closed figure for the simplified region M2. The segment SG2 and the segment SG3 have a common node N5 and are associated with each other. The feature shape classifying unit 113 performs a route search using the node N5, which is a common node, as a departure point, but the searched route does not form a closed figure. In such a case, the feature shape classification unit 113 determines No in step S510.

The inter-SG search process in step S520 will be described in detail with reference to the flowchart of FIG. 8 and FIGS.
First, the feature shape classifying unit 113 performs a process of setting end points (starting node and destination node) for searching for a route between the segments SG (step S521). Specifically, the feature shape classifying unit 113 extracts the nodes of the segment SG excluding the common node, and sets the node of one segment SG as the departure node and the node of the other segment SG as the end node. In the case of FIG. 17, the feature shape classifying unit 113 sets the node N4, the node N3, and the node N8 that are the nodes of the segment SG3 as the departure node, and the node N6, the node N7, the node N10, and the node N12 that are the nodes of the segment SG2. Set as.

  Next, the feature shape classifying unit 113 performs a process of searching for a route between the set end points (from the start node to the end node) (step S522). In step S522, the feature shape classification unit 113 refers to the map server 100 and searches for a route that satisfies a predetermined criterion. The predetermined reference in the present embodiment relates to road determination, traffic volume, and road width. The feature shape classification unit 113 performs a route search from the node set as the start node to the node set as the end point node.

  In FIG. 17, the feature shape classification unit 113 indicates a route No1 indicating a route from the node N4 to the node N6, a route No2 indicating a route from the node N4 to the node N7, and a route from the node 3 to the node 10 by the route search. Search for route No3, route No4 indicating the route from node N8 to node N12. FIG. 18 shows a list of route No. 1 to route No. 4 searched by the feature shape classification unit 113. Note that the feature shape classifying unit 113 may preferentially search for a path connecting nodes farthest from the common node, and proceed to the process of the next step S523 from the searched path. By doing so, a closed figure with a large area can be found at an early stage, and the processing efficiency can be improved.

  Next, the feature shape classification unit 113 performs a process of determining whether or not there is a path that satisfies the predetermined criterion (step S523). The feature shape classifying unit 113 proceeds to step S524 when there is a route in which road determination, traffic volume, and road width satisfy predetermined criteria (Yes in step S523). On the other hand, the feature shape classifying unit 113 ends the inter-SG search process when there is no route in which the road determination, the traffic volume, and the road width satisfy the predetermined criteria (No in step S523). When there is no route satisfying the predetermined criterion (No in step S523), the control unit 110 does not shift to the simplification process 600. However, the control unit 110 describes the segment extracted in the route segment extraction process 400, which will be described later. You may simplify using the non-characteristic shape simplification method.

  Road determination is a process for determining whether a searched route is substantially linear. Specifically, when the searched route is composed of a plurality of links, the connection angle between the links is within a predetermined angle range. It is to determine that there is. In FIG. 18, since route No. 1 to route No. 4 are both substantially linear within a predetermined range, the road determination is “◯” that satisfies a predetermined criterion.

  The traffic volume standard is based on the traffic volume stored in the network data. The traffic volume values shown in FIG. 18 indicate, for example, the annual average traffic volume, and the traffic volume value is 15 or more from the predetermined standard. Although route No2-route No4 of FIG. 18 satisfy | fill all the predetermined | prescribed reference | standard, route No1 has the traffic volume of 10, and does not satisfy | fill the predetermined | prescribed reference | standard. Note that a route with a large amount of traffic is a route through which many people pass, that is, when the road is displayed on a schematic map, there is an effect that a schematic map familiar to many people can be displayed.

  The road width standard is based on the average road width of the route using the road width information for each link stored in the network data, and the predetermined standard is a road width exceeding 3 m. To do. In FIG. 18, route No 3 and route No 4 satisfy a predetermined criterion, but route No 1 and route No 2 do not satisfy a predetermined criterion. That is, in step S523, the feature shape classifying unit 113 determines that the route No3 and the route No4 are routes that satisfy a predetermined criterion, and proceeds to step S524.

  The predetermined standard is not limited to these, and various standards may be used. For example, a route including a new road may be determined with priority. This is because people are interested in the new road. Further, a route having a sidewalk may be determined with priority. For example, in the case of a rough map for pedestrians, it is important to display the road that the sidewalk has. Alternatively, a road on which a bicycle can easily pass may be determined with priority. The map for people who want to enjoy cycling is important because it is important to display roads where cars can easily pass. These criteria are all achieved by using attribute information of network data.

  When there is a route that satisfies the predetermined criterion in step S523 (Yes in step S523), the feature shape classification unit 113 performs a process of determining an optimum route among the routes that satisfy the predetermined criterion (step S524). In FIG. 18, the patent shape classification unit 113 determines a route No. 3 having a high reference for road determination, traffic volume, and road width as an optimum route from the route No. 3 and the route No. 4 satisfying predetermined criteria. In step S524, the feature shape classifying unit 113 determines a route having a high predetermined criterion as an optimal route. However, the optimal route is not limited to this, and various criteria may be used.

  Next, the feature shape classification unit 113 performs a process of newly registering the determined optimum route as a segment (step S525). The feature shape classification unit 113 newly registers the link L12-link L13 constituting the route No3 determined as the optimum route as the segment SG5 that is a combination of the segment SG2 and the segment SG3, and ends the inter-SG search process.

  When the search process between segments SG (step S520) is completed, the feature shape classifying unit 113 performs a process of determining whether or not a segment is newly registered (step S540). If the feature shape classifying unit 113 determines that the segment is newly registered (Yes in step S540), the feature shape classifying unit 113 proceeds to step S510. On the other hand, when the feature shape classification unit 113 determines that the segment is not newly registered (No in step S540), the feature shape classification process is terminated.

  The feature shape classifying unit 113 determines that a segment is newly registered based on the newly registered segment SG5 in the search process between the segments SG (Yes in step S540), and proceeds to step S510. As shown in FIG. 17, the feature shape classifying unit 113 determines that a closed figure having node N3−node N4−node N5−node N7−node N10−node N3 as an end point is configured.

Next, the simplification process will be described with reference to the flowchart of FIG. 7 and FIGS. 9, 10, 11, 12, 15, and 19. FIG.
The simplification unit 114 performs a process of simplifying the feature shape step by step (step S610). FIG. 15 shows a closed figure A (L5-L6-L9-L10-L13-L12) represented by a thick line as a feature shape and links L7-L8, link L17, link L15, link L4, link L14 as non-feature shapes. , Link L15, link L11, and link L16 are shown. The simplification unit 114 compares the feature shape with a geometric shape such as a circle, ellipse, or n-gon that has been prepared in advance, and identifies the geometric shape closest to the closed figure. In FIG. 15, the simplification unit 114 specifies a triangle as a geometric shape approximated from the feature shape of the closed figure A.

  The simplification unit 114 simplifies the identified triangle using a triangular sample shape as shown in FIG. The simplification unit 114 selects a sample shape that most closely approximates the feature shape, and simplifies in steps toward the selected sample shape through a technique such as normalization. The simplification unit 114 selects an isosceles triangle whose end points are the node N3, the node N5, and the node N10 of the closed graphic A as the sample shape that most closely approximates the closed graphic A that is the characteristic shape with reference to FIG.

  The simplification unit 114 simplifies the closed figure A into an isosceles triangle step by step. In FIG. 19, the characteristic shape simplified by the simplified unit 114 by linearizing the end points of the closed graphic A (step 1) is indicated by broken lines. The simplified feature shape (stage 1) is composed of the link L100, the link L110, and the link L120 with the node N3, the node N10, and the node N5 as end points. The simplification unit 114 stores an evaluation score corresponding to the degree of approach to the sample shape selected for the feature shape in step 1. The feature shape in stage 1 in FIG. 19 is a geometric triangle, which is different from the sample shape isosceles triangle, and therefore the evaluation point 50 is stored.

  The simplification unit 114 simplifies the triangle simplified in step 2 into an isosceles triangle. In FIG. 20, the characteristic shape simplified by the simplification unit 114 (step 2) is indicated by a broken line. The simplified feature shape (stage 2) includes a link L200, a link L110, and a link L220 with the node N200, the node N10, and the node N5 as end points. The simplification unit 114 transforms into an isosceles triangle of stage 2 by performing an equal area transformation on the triangle of stage 1. As illustrated in FIG. 20, the simplification unit 114 sets an auxiliary line AL1 that passes through the node N3 and is parallel to the link L110, and specifies the position of the node N200 that is the vertex of the isosceles triangle on the auxiliary line AL1. The feature shape in stage 2 in FIG. 20 is an isosceles triangle having N200 as a vertex, and since it is a sample shape isosceles triangle, the evaluation point 90 is stored. The simplification unit 114 further arranges the feature shape of the stage 2 with reference to the inner center of the feature shape of the stage 1.

  Further, as a simplification (stage 3), the simplification unit 114 simplifies the feature shape from an isosceles triangle to an equilateral triangle having a high evaluation score of the sample shape in FIG. The simplified feature shape (step 3) includes a link L300, a link L310, and a link L320 (not shown) with the node N300, the node N310, and the node N320 as end points. The simplified unit 114 arranges the simplified feature shape in an equilateral triangle based on the inner center of the stage 2. Since the simplified portion 114 is a regular triangle having a sample shape, the evaluation point 100 is stored.

  FIG. 21 is a diagram illustrating a list in which feature shapes and evaluation points simplified for each stage are stored. The simplification unit 114 stores, as simplification of the feature shape, a simplification stage, nodes and links constituting the feature shape, a simplified shape, and an evaluation point.

  Next, the simplification unit 114 performs a process of simplifying the non-feature shape step by step (step S620). The non-feature shape is simplified step by step using the linearization shown in FIG. 9, the direction quantization shown in FIG. 10, and the length preservation shown in FIG. The simplification unit 114 simplifies each of the simplification methods of linearization, direction quantization, and length preservation alone or in combination. In the case of FIG. 15, the simplification unit 114 simplifies L11 and L16, L4, L7 and L8, L17, L14, and L15 in stages.

  The non-feature shape simplification method will be described with reference to FIG. FIG. 22 is a diagram illustrating evaluation points for single or combination non-feature shapes (L11 and L16). There are six types of non-feature shape simplifications from A to F, and 1 to 6 evaluation points are set from A to F. The simplification unit 114 performs each of the non-feature shapes step by step in the order of the simplification methods A to F, and stores them together with the evaluation points.

  Next, the simplification unit 114 performs a process of joining the feature shape and the non-feature shape for each stage stored (step S630). As shown in FIG. 20, when simplification is performed, the node position changes depending on the stage. In FIG. 20, with the simplification of the feature shape (stage 2), the node N3 has moved to the position of the node N200. In addition, the positions of nodes and links are also moved by the simplification stage for non-feature shapes (not shown). In step S630, the simplification unit 114 performs a process of joining the node N200, the link L16, and the link L4 using the connection information of the network data. When the simplified unit 114 connects the feature shape and the non-feature shape, the position of the feature shape is not moved, but the position of the non-feature shape is moved. The simplification unit 114 performs a process of connecting with a pattern obtained by multiplying each of the feature shape simplification stage and the non-feature shape simplification stage. In the present embodiment, the number of characteristic shape simplification steps is 3, the number of non-feature shapes is six, and the number of non-feature shape simplification steps is 6, and processing of connecting them by 108 patterns is performed.

  Next, the simplification unit 114 performs a process of determining whether there is a contradiction in the phase relationship compared to before the connected characteristic shape and non-characteristic shape are simplified (step S640). This process determines whether there is a problem that a road that is not originally connected is connected or a road that is originally connected is not connected. The simplification unit 114 performs the intersection determination of each line segment, and determines that there is no contradiction in the phase relationship if it intersects at the intersection position before simplification (Yes in step S640), and proceeds to step S650. On the other hand, the simplification unit 114 performs the intersection determination of each line segment, and determines that there is a contradiction in the phase relationship (No in step S640) unless it intersects at the intersection position before simplification, and the simplification process ends. To do. The method for determining the phase relationship before and after simplification is not limited to this method, and various methods exist.

  If it is determined in step S640 that there is no contradiction in the phase relationship, the evaluation unit 115 performs a process of calculating the total evaluation point by adding the evaluation points of the feature shape and the non-feature shape (step S650). The evaluation unit 115 performs non-feature shapes L11 and L16 (simplification method A: evaluation point 1), non-feature shape L4 (simplification method A: evaluation point 1) in stage 1 (evaluation point 50) of the feature shape, Non-feature shapes L7 and L8 (simplification method A: evaluation point 1), non-feature shape L17 (simplification method A: evaluation point 1), non-feature shape L14 (simplification method A: evaluation point 1), The non-feature shape L15 (simplification method A: evaluation point 1) is added together, and the total evaluation point 56 of the combination of these simplifications is stored. The evaluation unit 115 calculates and stores the total evaluation points while changing the feature shape and non-feature shape simplification methods step by step.

  Next, the evaluation unit 115 performs a process of storing the combination of the simplification methods for the highest total evaluation score (step S660). The combination of the simplification methods for the highest total evaluation point is the closest to the geometric shape and is simplified without any contradiction in the phase relationship, and an easy-to-understand schematic map can be created. As described above, a simplified closed figure is formed in the feature shape.

  In the simplification process of FIG. 7, in the present embodiment, it is determined whether or not there is a contradiction in the phase relationship (step S640), and a total evaluation score of a combination of a feature shape and a non-feature shape with no contradiction is calculated (step S640). S650), the processing order may be changed. That is, the evaluation unit 115 calculates the total evaluation point in step S650, and determines whether there is a contradiction in the phase relationship from the highest total evaluation point of the combination of the simplified feature shape and the non-feature shape simplification method. It may be determined (step S640).

  Next, the map generation unit 116 refers to the combination of the simplification methods having the highest total evaluation score stored in the storage unit 104, the facility database 107, the route database 106, and the map database 105, and creates a rough map. (Not shown). The map generation unit 116 arranges the facility point BP, the facility name Z21, etc. in the simplified network data shape based on the referenced simplification method, and creates a schematic map. The arrangement of the facility point BP and the facility name Z21 may be arranged based on the position information of the facility point BP and the facility name Z21, or may be arranged manually by an operator. The schematic map created by the map generation unit 116 is transmitted to the display terminal 200 by the communication unit 102 via the Internet INT and displayed on the display panel 212.

  In the above embodiment, the display terminal 200 is a portable smartphone, but may be a PC terminal. Although the schematic map created by the map generation unit 116 is displayed on the display panel 212, it may be output as a printed matter. Although the creation of the approximate map is performed by the server system 1000, the display terminal 200 may include the map server 100 and generate the approximate map.

As described above, in Patent Document 1, although feature parts such as closed figures are extracted and simplified, the simplification is based only on the shape of the road, and features other than the shape of the road are not considered. . Therefore, for example, the user desires to extract and simplify links indicating major roads such as national roads and prefectural roads based on road type, or to extract and simplify links with large traffic volumes based on traffic volume. There was a problem that it was not possible to create a rough map according to the subject. In this embodiment, the shape of a feature corresponding to a specific attribute based on a network having information on the attribute of the feature corresponding to a linear feature that can travel in a plurality of directions via a branch point. Is generated as shape information of a shape simplified to a specific shape, thereby solving the problem and making it possible to create a simplified map that is convenient for the user.
On the other hand, in this embodiment, the shape of the feature corresponding to the specific attribute is generated as the shape information of the shape simplified to the specific shape, so that the number of the features is reduced, and there is no closed figure. Challenges also arise. Even in such a case, it is possible to extract a feature graphic that constitutes a closed graphic by using a feature having another attribute (for example, performing a search process between segments SG). A map can be generated.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect.

100 ... Map server 105 ... Map DB
106 ... route DB
107 ... Facility DB
108 ... Traffic information DB
200 ... Display terminal 1000 ... Server system SG ... Segment Z11 ... Text data Z21 ... Facility name ND ... Node LK ... Link INT ... Internet BS ... Base Bureau BP ... Facility point AL1 ... Auxiliary line

Claims (9)

Corresponding to linear features that can travel in a plurality of directions via a branch point, a storage unit that stores network data having information on attributes of the features;
A map generation device comprising: a control unit that generates, based on the network data, the shape of the feature corresponding to a specific attribute as shape information of a shape simplified to a specific shape, and generates a map having the shape information .   The map generation apparatus according to claim 1, wherein the specific shape is a simplified closed figure.   When the feature corresponding to the first attribute does not constitute the simplified closed figure, the control unit is simplified using the feature corresponding to the first attribute and the second attribute. The map generation apparatus according to claim 2, which forms a closed figure. The network data has information that enables a search for a route from a predetermined point of the feature to another point,
When the feature corresponding to the first attribute does not form the simplified closed figure, the control unit also uses the feature corresponding to the second attribute based on the route searched based on the network data. The map generating apparatus according to claim 3, wherein the map forms the simplified closed figure.   The map generation device according to claim 1, wherein the control unit generates the shape information of the simplified closed graphic by simplifying a closed graphic before being simplified.   The map generation device according to any one of claims 1 to 5, wherein the feature includes a road, a route, or a river. The network data has network level information which is an index preferentially searched in route search,
The map generation apparatus according to claim 1, wherein the attribute includes information on the network level.   The map creating apparatus according to claim 1, wherein the attribute includes information on a traffic volume of a person or a vehicle. The map creating apparatus according to claim 1, wherein the attribute includes information on a sidewalk.

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