JP4833915B2 - Method and apparatus for generating electronic map database - Google Patents

Description

  The present invention relates to a method for generating an electronic map database, and more particularly to a method for generating a new database by effectively utilizing information in an existing database.

  In recent years, the use of map data digitized so as to be usable by computers (hereinafter referred to as “electronic map data”) has become widespread. The electronic map data is used for displaying a map on a so-called personal computer, a vehicle-mounted navigation system, providing a map via the Internet, and creating a map as a printed matter.

  Since roads, buildings, etc. change over time, the electronic map database must be updated sequentially. In addition, for example, when a new function using an electronic map database is required, it may be necessary to reconstruct the entire database.

  In recent electronic map databases, it is often required to give various attribute information to roads and buildings. However, when the database needs to be reconstructed, the structure of the entire database, including how to provide attribute information, is greatly modified, and the information contained in the existing database cannot be used effectively. For this reason, it is necessary to manually transfer information contained in the existing database to a new database one by one. This is a very large amount of work and has become a heavy load for database construction.

  In particular, when using a so-called house map as an existing database, the above-mentioned problem is remarkable. In addition to the name of each residence, the residential map includes detailed information such as one-way streets, closed roads, and other regulatory information, as well as the presence of median strips and sidewalks. Such information is included as display data in principle, and is not associated as attribute information with a predetermined road or the like. Conventionally, such information could not be efficiently reflected in a new database.

  The present invention has been made in view of the above problems, and an object of the present invention is to effectively utilize information included in an existing database and reduce a generation load of a new database.

  In the present invention, as a first configuration, attribute information is set based on an existing database when a new database of an electronic map is generated. The existing database is an electronic map database including map components. The new database is an electronic map database configured so that attribute information can be set for each element set on the map. These databases are compared, and when the map components included in the existing database are in a predetermined overlapping state with respect to the elements in the new database, attribute information corresponding to the map components is set in the elements. An element means an element to which attribute information is added, such as a road, a building, and a field, and includes a point area, a line area, a surface area, a spatial area, nodes and links constituting a database for route search, and the like. . By doing so, it is possible to efficiently transfer the attributes expressed in the form of map components in the existing database to the new database. Map elements need only overlap with elements in the new database and do not have to be defined in correspondence with these elements.

  The electronic map in the present invention means a map expressed by so-called vector data in a narrow sense, but means all electronic data expressing a topography in a broad sense. For example, a map configured as image data such as a bitmap or a GIF, a photograph expressing a terrain such as an aerial photograph, and the like are also included in the broad electronic map. The electronic map is not necessarily two-dimensional, and may include a three-dimensional model or a three-dimensional image.

  In the present invention, map components include various patterns and images represented by dots, lines, planes, solids, or combinations thereof, in addition to symbols displayed on a so-called map. It may be a three-dimensional model and image. Since the symbol is set based on a certain rule according to the attribute of the constituent element, there is an advantage that the attribute information can be accurately and accurately set in the new database by using the symbol of the existing database.

  On the other hand, when various patterns and images are used, attributes can be acquired in a wide range where a certain symbol is not defined. As an example, when a pattern is found in which border lines for stopping cars are arranged at a certain interval in a certain area, even if the symbol “P” or the like of the parking lot is not attached, that area is designated as a parking lot. Judgment can be made. In addition, for a road where a yellow center line is found, an attribute such as prohibition of protrusion can be set. The number of floors of the building may be set as attribute information based on the photograph showing the side of the building.

  Thus, when setting an attribute based on various patterns and images, it is preferable to prepare a pattern database for analyzing the patterns and images in advance. The pattern database is configured, for example, by storing patterns, images, and attributes in association with each other. By referring to this pattern database, it is possible to specify the attribute for the area relatively easily. In order to avoid erroneous attribute assignment, the operator may transfer the attribute after confirming whether the attribute set by the analysis is correct or not.

  The symbol includes, for example, a symbol (hereinafter referred to as “point symbol”) arranged with a predetermined point on the map as a representative point. Examples of point symbols include one-way streets, closed roads, traffic lights, fire hydrants, pedestrian bridges, and pedestrian crossings. Moreover, the thing whose shape is not necessarily constant like a house frame can also be included. For these point symbols, for example, whether or not the attribute can be set can be determined based on whether or not a representative point of the symbol exists in the element. This determination can be applied to elements that do not have a width, such as nodes, links, or point areas, based on whether or not the representative point is on that element. This is useful for elements having a certain range.

  In this determination, it is also possible to consider whether or not the relative declination between the element and the symbol is within a predetermined range. For example, the relative declination means, for example, an angle formed by the direction along the road and the direction of the symbol. By considering such a declination, it is possible to accurately determine whether or not the attribute assignment is appropriate. Such determination is particularly useful for links, line regions, surface regions, and spatial regions in which relative declination can be defined based on a predetermined reference line.

  The symbols of the present invention also include symbols (hereinafter referred to as “range symbols”) arranged corresponding to certain planes or lines on the map. Range symbols include, for example, sidewalks, separators, bridges, tunnels, cuts, fills, lane numbers, and the like. Also includes facility attributes such as rice fields, fields, orchards. For these range symbols, for example, whether or not the attribute can be set can be determined based on whether or not at least a part of the symbols exists in the region.

  Since the attribute corresponding to the range symbol is not necessarily uniform in the entire area, different attribute settings may be possible in a part of the area. For example, when the new database includes a link representing a road and a node representing an intersection of the links, the attribute setting based on the range symbol may be individually performed at both ends of the link. In this way, for example, even when a separation band exists only at one end of the link, it is possible to perform appropriate attribute assignment.

  The elements in the present invention can be defined in various ways. For example, the elements can be polygons set for roads included in the new database. In addition to the case where the polygon is defined in advance in the new database, a polygon having a predetermined width corresponding to the region may be generated from a linear road defined in the new database.

  In the present invention, as a second configuration, the restriction information is set in the electronic map database by the following method. First, a map database including a link representing a road, a node representing an intersection of the links, and separation band information indicating the presence or absence of a separation band at an end point of the link is input. And the restriction information regarding the direction which can pass in an end point is set based on separation zone information. For example, the restriction information can be set so as to restrict the passage in the direction passing through the separation band. In the case where the separation band exists only at one of the end points of the link, the handling of the other end can be variously selected. For example, the restriction information may be set on the other end of the link as if the separation band exists similarly, or the restriction information different from that on the side where the separation band exists may be set on the other end.

In the present invention, as a third configuration, the restriction information is given to the electronic map database by the following method. First inputs and links representing roads, and a node representing an intersection of links, map data including the control information in the traffic direction imparted as the attribute information for at least a portion of the link from the map database. Then, based on the connection state of the regulation information and link map data the input, control information in the traffic direction for at least some of the unset links that have not been granted, confer regulation information as the attribute information. Depending on the structure of the database, a substantially continuous road may be defined by being divided into a plurality of links. According to the third configuration, in such a case, it is possible to supplement the deficiencies in the restriction information originally given to each link and to define appropriate restriction information for each link.

  In the third configuration, for example, when restriction information having the same content is set for links connected before and after an unset link, a method of setting the restriction information to an unset link is adopted. Can do. This is because it can often be regarded as a substantially continuous road.

  Moreover, it is good also as what sets based on the regulation information attached | subjected to the link which at least one of a non-set link and road classification and the number of lanes is the same. This is because when the road type and the number of lanes are different, the regulation contents may be different even on a substantially continuous road.

  Furthermore, it is good also as what sets based on the regulation information attached | subjected to the link in which the angle between unset links is in a predetermined range. This is because, for example, a road that is bent at a right angle or an acute angle may have different regulation contents even on a substantially continuous road.

  The conditions exemplified here may be applied individually or in combination. The above conditions are only examples, and the restriction information may be applied in consideration of other conditions.

  The map database may be configured as a unit drawing with a predetermined area. For roads that cross adjacent unit drawings, there may be a case where a link existing in each unit drawing is defined by providing a node at the boundary of the drawing. In such a case, the restriction information given in one unit drawing may be set in the link in the other unit drawing for two links corresponding to roads that span adjacent unit drawings. In this way, it is possible to efficiently provide the regulation information for the road that crosses the boundary of the unit drawings.

  In the present invention, as a fourth configuration, when an electronic map database is generated by the following method, the vertical relationship of roads at a three-dimensional intersection is set. In this setting, an existing database including roads having edge lines is used. In addition, the new database can set attribute information indicating the vertical relationship of each road at a portion where roads intersect three-dimensionally. Then, in the new database, the vertical relationship of the roads in the new database is set based on the overlapping state of the roads constituting the three-dimensional intersection and the edge line in the predetermined area from the center of the three-dimensional intersection. For example, if it is determined that an edge line of another road intersects a certain road, the road is below the other road. Thus, by utilizing the overlap of the edge lines, it is possible to efficiently set the vertical relationship of the road.

  In the second and third configurations of the present invention, it is not always necessary to use an existing database. However, the restriction information may be set after setting the presence or absence of a separation band based on the existing database. . In the present invention, the electronic map database generation method described above may be appropriately combined or a part thereof may be omitted.

  The present invention is not limited to an aspect as a method for generating an electronic map database, and can be configured in various aspects. For example, you may comprise as a production | generation apparatus for producing | generating an electronic map database. Such a generation apparatus is realized by configuring a functional unit that realizes various functions described in the above-described generation method as a software by a computer or a specific circuit. Further, the present invention may be configured as a computer program for realizing these functions or a recording medium on which such a computer program is recorded.

  Here, as a recording medium, a flexible disk, a CD-ROM, a magneto-optical disk, an IC card, a ROM cartridge, a punch card, a printed matter on which a code such as a barcode is printed, an internal storage device of a computer (RAM, ROM, etc. A variety of computer-readable media can be used, such as memory) and external storage devices.

The embodiment of the present invention will be described by dividing it into the following items.
A. Device configuration:
B. Attribute setting process:
B1. Sidewalk attribute acquisition processing:
B2. Separation zone attribute acquisition processing:
B3. No entry attribute setting process:
B4. One-way attribute acquisition processing:
B5. Passing attribute acquisition processing:
B6. Elevated attribute acquisition processing:
C. effect:
D. Variations:

A. Device configuration:
FIG. 1 is an explanatory diagram showing a configuration of an electronic map data generation apparatus as an embodiment. The generation device 10 is configured by installing a computer program for realizing the function as the generation device in a general-purpose computer. The generation apparatus 10 inputs the city map database 20 and the road database 30 and outputs a new road database 30a. These databases are provided and stored by a server connected to the generation apparatus 10 via a network.

  FIG. 2 is an explanatory diagram showing an overview of the database. The city map database 20 is an existing electronic map database representing roads and the like. In the city map database 20, the road is displayed as an area having an edge line R. In addition, symbols such as a sidewalk S, a separation zone M3, a one-way street M1, and a traffic stop M2 are also displayed. Furthermore, as shown in the area E, the road overlap state is expressed in the three-dimensional intersection. In the city map database 20, for example, the one-way street M1 is not defined as a road attribute, and the display position is merely set by coordinates such as latitude and longitude.

  The road database 30 is an electronic map database newly generated based on the city map database 20. In the road database 30, as shown in the figure, a road is defined as a link as a line segment and a node that is an intersection of the links. It is possible to define attribute information for each link and node.

  Returning to FIG. 1, the configuration of the generation apparatus 10 will be described. The generation apparatus 10 inputs the road database 30 in which links and nodes are defined in this way, adds attribute information with reference to the city map database 20, and outputs the new road database 30a. The functional blocks of the generation device 10 are also shown in the figure. In this embodiment, these functional blocks are configured in software, but may be configured in hardware.

  The command input unit 11 inputs a command from an operator through operation of the keyboard, mouse, and the like in the generation apparatus 10. The database reference unit 12 refers to the city map database 20 and the road database 30 based on this command.

  The polygon generation unit 13 generates a closed figure (hereinafter referred to as a polygon) having a predetermined area from each link defined in the road database 30. In this embodiment, polygons are generated by giving each link a width corresponding to the lane width.

  The attribute setting unit 15 has a function of setting attribute information for a link in the road database 30. For setting the attribute information, the polygon generated by the polygon generation unit 13, the city map database 20, and the road database 30 are referred to as appropriate. In the present embodiment, functional blocks shown in the drawing are provided according to the set attributes.

  The sidewalk setting module 15a sets the presence or absence of a sidewalk. The separation band setting module 15b sets the presence or absence of a separation band. The entry prohibition setting module 15c sets the entry prohibition direction based on the presence or absence of a separation zone. The one-way setting module 15d sets the presence / absence of one-way traffic. The traffic closing setting module 15e sets whether or not traffic is closed. The elevated setting module 15f sets the vertical relationship of the road at the three-dimensional intersection.

  The result output unit 14 receives the setting result by the attribute setting unit 15, associates attribute information with each link, and outputs it as a new road database 30a. In the present embodiment, for the sake of convenience, the database is exemplified as one that outputs a database separate from the road database 30, but an aspect of updating the road database 30 may be adopted.

  FIG. 3 is an explanatory diagram illustrating the structure of the new road database 30a. Consider the case where links L1 to L7 exist around nodes N1 and N2, respectively, as shown in the upper part of the figure. The content of the data about the link L4 is shown in the lower part of the figure. Data such as name, type, group, shape, and attribute are included. The type is information indicating the type of road such as a national road or a prefectural road. A group is information that associates a plurality of links. For example, when the links L1, L4, and L7 are all a single national highway, they can be associated as a group G1. The shape is information listing the latitudes and longitudes of the link passing points N1, P1, P2, and N2. The attribute is information that gives the structure, traffic regulation, and the like for the link L4. In FIG. 3, information on sidewalks, median strips, one-way traffic, entry prohibition, stairs, traffic stoppages, and overpasses is exemplified as attributes. However, some types of information can be set as appropriate, such as adding width.

B. Attribute setting process:
FIG. 4 is a flowchart of attribute setting processing. This is a process executed by the CPU of the generation device 10. When the process is started, the CPU refers to the city map database 20 and the road database 30 and inputs the respective map data (step S10). The image of the input data is illustrated in the figure.

  Next, the CPU generates a polygon based on the road data (step S12). The state of polygon generation is illustrated in the figure. As indicated by the broken lines in the figure, each polygon can be defined by giving a width to the links constituting the road data. The width of the polygon is set based on the lane, but may be a constant width.

  The CPU obtains the attribute by superimposing the generated polygon and the city map data (step S14). A method for setting each attribute such as a sidewalk, a separation zone, entry prohibition, one-way traffic, no-passage, and elevated will be described later.

  Finally, a new road database is generated by associating the attribute thus obtained with the link (step S16), and the CPU ends the attribute setting process.

B1. Sidewalk attribute acquisition processing:
FIG. 5 is a flowchart of the sidewalk attribute acquisition process. This is one of the processes executed by the CPU in step S14 in FIG. This is a process for determining the presence or absence of a sidewalk and setting its attribute for each link based on the sidewalk symbol described in the city map data.

  When this process is started, the CPU selects a link to be set (step S20). For example, the links included in the road database may be selected sequentially. Next, the sidewalk layer of the city map data is input (step S22). The sidewalk layer is a layer that stores data for displaying the sidewalk S shown in the city map data of FIG.

  The CPU performs polygon extension processing for the setting target link (step S24), and determines whether there is a sidewalk (step S26). For each link, a polygon is generated by the process shown in step S12 of FIG. 4 earlier. In step S24, the width of the polygon is expanded in order to appropriately determine the presence or absence of a sidewalk. The state of polygon expansion is illustrated in the figure. The left side is a polygon corresponding to the road width set in step S12. On the right side, a state is shown in which the width of the polygon is expanded to the left and right by dw.

  The presence or absence of a sidewalk is determined by whether or not a sidewalk symbol exists in the polygon. As shown in the figure, in the polygon of the road width, there is a possibility that the symbol of the sidewalk does not exist in the polygon even when the sidewalk exists. On the other hand, by performing polygon expansion processing, it is possible to determine the presence or absence of a sidewalk without omission.

  The extension width dw can be arbitrarily set in light of such a purpose. If the extension width dw is extremely small, a sidewalk cannot be detected. On the other hand, when the extended width dw is extremely large, it may be a cause of erroneous determination due to a sidewalk attached to another road. The expansion width dw is preferably set in consideration of both effects.

  If it is determined by the above processing that there is a sidewalk, the CPU sets the sidewalk attribute information as a target link (step S20), and ends the sidewalk attribute acquisition process. Although FIG. 5 illustrates setting processing for one link, the CPU executes similar processing for each link included in the road database.

  FIG. 6 is an explanatory diagram illustrating a situation in which an erroneous determination of the presence / absence of a sidewalk may occur. Consider a case where the link La1 is not provided with a sidewalk and a link La3 intersecting there is provided with a sidewalk. As shown in the drawing, in the area Aa6, there is a sidewalk symbol inside the polygon Pa1 set for the link La1. In the processing of the present embodiment, in such a case, there is a possibility that an erroneous determination occurs regarding the presence or absence of the sidewalk attribute.

  Consider a case where the elevated link La2 is not provided with a sidewalk and a link La3 passing thereunder is provided with a sidewalk. As illustrated, in the area Aa2, a sidewalk symbol exists inside the polygon Pa2 set for the link La2. In the processing of the present embodiment, in such a case, there is a possibility that an erroneous determination occurs regarding the presence or absence of the sidewalk attribute.

  Such erroneous determination may be confirmed individually by the operator and the data corrected. Moreover, it is good also as what performs the process for avoiding this misjudgment by step S26 of FIG. For example, it is possible to avoid an erroneous determination such as the area Aa6 by determining the presence / absence of a sidewalk symbol by a polygon near the midpoint of the link. Further, by determining the presence / absence of a sidewalk symbol at a plurality of locations on the link, it is possible to avoid an erroneous determination like the area Aa2.

B2. Separation zone attribute acquisition processing:
FIG. 7 is a flowchart of separation band attribute acquisition processing. This is one of the processes executed by the CPU in step S14 in FIG. This is a process for determining the presence or absence of a separation band and setting its attribute for each link based on the separation band symbol described in the city map data. The presence / absence of a separation band is also determined individually for the start and end points of the link.

  When this process is started, the CPU selects a link to be set (step S30) and inputs a separation band layer of city map data (step S31).

  Next, the CPU determines the presence or absence of a separation band based on these data (step S32). In this embodiment, the presence / absence of a separation band is determined based on whether or not a separation band symbol exists in the polygon set for the link. This determination can be made near the midpoint of the link, for example. In this embodiment, the presence / absence of a separation band is also determined at the start and end points of the link (steps S33 and S34). This determination can be made based on, for example, whether or not the start side or the end side of the polygon intersects the symbol of the separation band.

  When the target link is an object of erroneous determination check (step S35), the CPU performs erroneous determination check (step S36), sets the separation band attribute information (step S37), and performs this processing. Exit. Check targets for erroneous determination can be set in advance. In the present embodiment, links that are three-dimensionally crossed are set as check targets. In the misjudgment check, a map is displayed for the link to be checked, and the operator checks and corrects it individually. It is good also as what corrects automatically by the process mentioned later.

  FIG. 8 is an explanatory diagram showing a method for determining the presence or absence of a separation band. Regarding the link Lb1, since the separation band symbol Sb1 exists in the polygon Pb1 near the middle point, it is determined that there is a separation band. However, it is determined that there is no separation band at the start point or the end point. Regarding the link Lb2, since there is no separation band symbol in the polygon Pb2, it is determined that there is no separation band.

  As for the link Lb3, since there is no separation band symbol in the polygon Pb3 near the midpoint, it is determined that there is no separation band. However, since the separation band symbol Sb3 exists across the start point Nb3, it is determined that there is a separation band on the start point side.

  Regarding the link Lb4, it is determined that there is no separation band at the start point and the end point. However, since the separation band symbol provided in the link of the elevated road exists in the polygon Pb4 in the area Ab4 near the middle point, the separation is performed. There is a possibility that it is erroneously determined that there is a belt. For links that are three-dimensionally crossed, the erroneous determination is corrected by an erroneous determination check (step S36).

  Correction of misjudgment about link Lb4 can be performed by the following method in addition to correction by an operator. This correction is performed on a link determined to have a separation band near the midpoint and no separation band at the start and end points. When there is a link that satisfies such a condition, such as the link Lb4, it is determined whether or not the start point Nbs and the end point Nbe of the separation band that intersects with this link exist in the polygon Pb4 near the middle point. If at least one of the start point Nbs and the end point Nbe exists, it is determined that there is a separation band, and if none exists, it is determined that there is no separation band. In the example of FIG. 8, it is determined that there is no separation band based on this condition.

  In the separation band, there is also an implant Sb5 shown in FIG. When such planting is handled as a separation band, inconvenience may arise in relation to traffic regulation settings. Therefore, in this embodiment, the planting Sb5 is set as an attribute in the node Nb5. This determination is performed by generating a square polygon Pb5 having a predetermined size with the node Nb5 as the center of gravity, and whether or not the planting Sb5 is included in the polygon Pb5. When the implantation Sb5 is not included in the polygon Pb5, it is treated as a separation band, and when it is included, it is not treated as a separation band.

B3. No entry attribute setting process:
FIG. 9 is a flowchart of the entry prohibition attribute setting process. This is one of the processes executed by the CPU in step S14 in FIG. This is a process of setting an attribute that restricts the direction in which a node can pass based on attribute information indicating the presence or absence of a separation band. The attribute information indicating the presence / absence of the separation band is not necessarily set by the method described with reference to FIGS. 7 and 8, and may be set by another means.

  When this process is started, the CPU selects a target intersection (step S40). The target intersection may be sequentially selected from the nodes to which the separation band attribute is assigned to any one of the link, the start point, and the end point. The CPU also inputs a separation band attribute (step S42).

  Next, the CPU sets an entry prohibition attribute based on the separation band attribute (step S44). The setting method is illustrated in the figure. In this embodiment, entry in a direction physically crossing the separation zone is prohibited. In the example in the figure, a case is considered in which a separation band indicated by a thick line exists at the intersection Is1 of the roads R1 to R4. In this case, traffic in the direction indicated by the arrow in the drawing is prohibited because it passes through the separation zone. The entry prohibition attribute may be set as part of the link or node attribute, or may be defined as restriction information different from these.

  As shown in the figure, consider a case in which a separation band exists only at one of the start point and end point of a link. For road R3, there is a separation zone at intersection Is1, but there is no separation zone at intersection Is2. In such a case, entry prohibition may not be provided at the intersection Is2, and restrictions similar to those at the intersection Is1 may also be provided at the intersection Is2.

B4. One-way attribute acquisition processing:
FIG. 10 is a flowchart of the one-way attribute acquisition process. This is one of the processes executed by the CPU in step S14 in FIG. This is a process of setting a one-way attribute for each link in the road database based on the one-way symbol described in the city map data.

  When this process is started, the CPU selects a setting target link (step S50) and inputs a one-way symbol of the city map data (step S52). Then, based on the overlapping state of the polygon generated from the link and the one-way symbol, the presence / absence of one-way restriction is determined (step S54).

  The determination method is illustrated in the figure. In this embodiment, the center of gravity of the one-way symbol is defined as a representative point, and it is determined whether or not the representative point exists inside the polygon. For example, the link Lc1 in the figure is determined to be one-way because the representative point Mc1 of the one-way symbol is present inside the polygon Pc1. Regarding the link Lc2, since the representative point of the one-way symbol Mc2 is not included in the polygon Pc2, it is determined that there is no one-way traffic. In the present embodiment, the deviation angle θ between the one-way sign and the road is also considered. Usually, since the one-way symbols are arranged along the road, it is appropriate to determine that there is no one-way on the road when the deviation angle θ is larger than a predetermined reference value. This reference value can be arbitrarily set, and is set to 30 degrees in the present embodiment. For example, when the deflection angle θ between the link Lc3 and the one-way symbol Mc3 in the figure is 30 degrees or less, it is determined that the link Lc3 is one-way, and when it is greater than 30 degrees, it is determined that there is no one-way. Is done. In this embodiment, the presence / absence of one-way traffic is determined in consideration of both the position of the representative point and the deflection angle, but the determination may be made without considering the deflection angle.

  The CPU sets one-way attribute information according to the determination result of step S54 (step S56), and ends this process.

  FIG. 11 is a flowchart of the one-way stretching process. In step S14 of FIG. 4, this is one of the processes executed by the CPU, which is a process applied to the road database after the one-way attribute has already been set by the process of FIG. This is an extension process for a link for which a one-way attribute is not set, that is, a process for giving a one-way attribute based on the surrounding situation.

  When this process is started, the CPU inputs road data in which the one-way attribute is set (step S60). The electronic map database is managed by unit drawings in a certain area, and road data is also input by unit drawings. Based on the road data, the CPU performs an extension process to an adjacent drawing (step S61). The processing contents will be described later.

  Next, the CPU selects a link to be subjected to stretching processing (step S62), and determines whether or not stretching conditions described later are satisfied (step S63). If the stretching condition is satisfied (step S64), a one-way attribute is set for the target link (step S65), and the process ends.

  FIG. 12 is an explanatory view showing the stretching process of the adjacent view. As shown in the drawing, the two areas of Map1 and Map2 correspond to unit drawings, respectively. In the drawing Map2, it is assumed that one-way traffic is set in each of the links Ld1 and Ld3 in the illustrated direction. In the drawing Map1, it is assumed that links Ld2, Ld4, and Ld5 exist, but one-way traffic is not set. Nodes Nd1 to Nd3 are provided at the connection points of these links and the boundaries of the unit drawings.

  Consider the links Ld2 and Ld4. These links are connected to links Ld1 and Ld3 via nodes Nd1 and Nd2, respectively. There are no branches in the nodes Nd1 and Nd2. As described above, when there is no branch at the node including the boundary node of the unit drawing, the one-way regulation attached to the link in the adjacent drawing is extended as it is. By so doing, it is possible to set appropriate attribute information for the links Ld1, Ld2, Ld3, and Ld4 that substantially constitute one road.

FIG. 13 is an explanatory diagram showing conditions for the stretching process. In the road data composed of the links Le1 to Le10, a case where one-way traffic is set for the links Le1, Le5, Le7, and Le10 is illustrated. In the present embodiment, one-way extension is permitted when a link that is not set for one-way satisfies the following conditions.
1) In the case of two-way difference, extend one-way to the three-way intersection.
2) If there are three or more roads, one-way is extended when the following conditions are satisfied.
2a) One-way traffic in the same direction exists within a predetermined value in the forward or backward direction of the target link. The predetermined value can be arbitrarily set, and is set to 100 m in this embodiment.
2b) The road type and the number of lanes of the target link and the link for which one-way traffic is set are the same.
2c) The connection angle between the target link and the one-way link is within a predetermined value. The predetermined value can be set arbitrarily, and is set to 30 degrees in this embodiment.
Here, the link connection angle is the smaller of the angles formed around the intersection of the two links.

  In FIG. 13, consider a case where the target link is Le2. A one-way attribute is set for the backward link Le1 of the target link Le2, and the node Ne1 is a two-way road. Therefore, the one-way restriction of the link Le1 is extended to the node Ne2 of the three-way difference.

  Consider Le6 and Le8 as target links of three or more differences. Each of the links Le5, Le6, and Le8 is connected by one node. The connection angle between the links Le5 and Le6 is α1 (<30 degrees), and the connection angle between the links Le5 and Le8 is α2 (> 30 degrees). The road type and the number of lanes are the same for these links.

  For any link, there is a link Le5 to which one-way is attached at the rear, and Le7 and Le10 to which one-way in the same direction as the link Le5 is present within a predetermined distance R at the front. 2a) is satisfactory. The link Le6 satisfies the condition 2c) while the link Le8 does not satisfy this condition. Accordingly, the one-way restriction is set for the link Le6, and the one-way restriction is not set for the link Le8.

  In addition, in place of condition 2c) or in combination with condition 2c), when there are a plurality of target links such as links Le6 and Le8, a condition is set that one-way restriction is set for the link having the smallest connection angle. May be.

B5. Passing attribute acquisition processing:
FIG. 14 is a flowchart of the pass attribute acquisition process. This is one of the processes executed by the CPU in step S14 in FIG. This is processing for setting the presence or absence of a so-called car stop provided so that the vehicle cannot enter as an attribute.

  When this process is started, the CPU selects a setting target link (step S70), and inputs a road stop symbol of the city map data (step S72). Then, based on the overlapping state of the link and the traffic stop symbol, the presence / absence of traffic stop is determined (step S74).

The determination method is illustrated in the figure. In the present embodiment, the traffic stop attribute is set when the following two conditions are satisfied.
The traffic sign is crossing or touching the link. The angle θs between the traffic sign and the link is greater than or equal to a predetermined value. Here, the predetermined value can be arbitrarily set. In this embodiment, 30. Degree.

  In the figure, for the link Lf, when the closed sign is in the state of a to c, the closed attribute is set. It is not set in the state of d. In the state of e, the link Lf and the symbol intersect, but when the angle θs formed by both becomes shallower than 30 degrees, the traffic blocking attribute is not set.

  Based on the determination result in step S74, the CPU sets the passage stop attribute information (step S76), and ends this process.

  In the present embodiment, the case where it is determined whether or not the attribute can be set based on the intersection of the traffic sign and the link and the angle formed is exemplified. Various determination conditions can be set. For example, the determination may be made without taking into account the angle formed by the pass sign and the link. Further, as with one-way traffic or the like, the determination may be made based on whether or not the representative point of the traffic stop symbol exists inside the polygon generated based on the link.

B6. Elevated attribute acquisition processing:
FIG. 15 is a flowchart of the elevated attribute acquisition process. This is one of the processes executed by the CPU in step S14 in FIG. This is a process of giving the vertical relationship of the road as attribute information for a portion that is a three-dimensional intersection.

  When this process is started, the CPU detects a non-intersection from the road database (step S80). A non-intersection location refers to a location where links are intersected in a plane but no node is set at the intersection. This non-intersection portion corresponds to a three-dimensional intersection and becomes a target intersection of the elevated attribute acquisition process.

  Next, the CPU inputs the road shape of the city map data (step S82), and cuts out the determination area (step S84). In the figure, a method for cutting out the determination area is illustrated. A rectangle Af having a certain size is generated with the intersection Si between the link Lf1 and the link Lf2 as the center of gravity. The size of the rectangle Af may be set in advance, but in this embodiment, the size is gradually increased until six or more road edge lines appear in the rectangle. For example, in the example in the figure, the edge lines EL1 to EL6 exist in the rectangle Af.

  Within this rectangle Af, the vertical relationship is determined for the links Lf1 and Lf2 (step S86). The vertical relationship is determined by whether or not each link intersects the edge of the road within the rectangle Af. A link that does not intersect the edge line is determined to be an upper road. It is determined that the intersecting link is a lower road. For example, the link Lf1 does not intersect with any edge line, and thus is determined as an upper road. Since the link Lf2 intersects with the edge lines EL1 and EL3, it is determined as a lower road.

  Based on the result of this determination process, the CPU sets the elevated attribute information (step S88) and ends the process.

C. effect:
According to the map database generation method described above, attribute information can be given by effectively using information attached to an existing database such as a city map database. Further, more practical attribute information can be set by effectively utilizing information attached to the road database such as one-way extension processing and entry prohibition setting. As a result, it is possible to reduce the load in creating and expanding a new database.

D. Variations:
The attribute information can be set for various items other than those exemplified in the embodiment. FIG. 16 is an explanatory diagram illustrating an example of items as attribute information addition targets. For example, regarding the presence or absence of a traffic light, a fire hydrant, and the like, attribute information can be set by a method similar to the setting of a sidewalk or one-way (see FIGS. 5 and 10). For the pedestrian bridge pedestrian crossing, the attribute information can be set by the same method as the setting for closing (FIG. 14). For bridges, tunnels, cuts, and embankments, attribute information can be set by the same method as the sidewalk setting (see FIG. 5). As for the number of lanes, attribute information can be set by the same method as that for the separation zone (FIG. 7).

  In the present embodiment, the setting of attribute information related to roads is mainly exemplified, but the present invention is not limited to roads and can be applied. For example, facility attributes may be attached to facilities such as buildings, fields, fields, orchards based on symbols attached to an existing database. In such a case, for example, attribute information can be given based on a method similar to one-way, that is, based on whether or not a representative point of a symbol exists inside a polygon for displaying a facility.

The attribute setting processing (FIGS. 5 to 15) exemplified in the present embodiment does not necessarily have to be executed entirely, and may be selected and executed as appropriate.
The existing database is not limited to the city map database exemplified in this embodiment, and various electronic map data can be used. For example, as an existing database, a photograph showing the topography such as an aerial photograph can be used. The process in such a case will be described below as a modified example.

  FIG. 17 is an explanatory diagram showing a configuration of an electronic map data generation device 10A as a modification. It is an apparatus for setting attributes by referring to the aerial photograph 20A instead of the city map database 20 in the embodiment. Here, as an example of the aerial photograph 20A, the same functional blocks as those in the road embodiment including the parking lot Pa and the center line CL are denoted by the same numbers.

  The generation apparatus 10A according to the modification has a function of reading the aerial photograph 20A and analyzing an image pattern included therein. This function is realized by the pattern analysis unit 16 and the pattern database 17. The pattern database 17 is a database that stores various image patterns included in the aerial photograph 20A and their attributes in association with each other. For example, in the example in the figure, a pattern in which short line segments constituting a car frame are arranged at regular intervals, such as a parking lot Pa, and an attribute “parking lot” may be associated in the pattern database 17. it can. Further, for the center line CL, the pattern database 17 can associate yellow with the restriction information “prohibition of protrusion”.

  The pattern analysis unit 16 defines attributes for each region included in the aerial photograph 20 </ b> A while referring to the pattern database 17. The entire aerial photograph 20A may be analyzed, or the pattern analysis may be performed only on the area corresponding to the polygon generated by the polygon generation unit 13 in the road database 30. In addition, it is possible to confirm with the operator whether or not setting is possible before defining the attribute. The attributes set in this way are transferred to the attribute setting unit 15 and transferred to the road database 30 by the same method as in the embodiment.

  If the attribute is set based on the pattern analysis as described above, the attribute can be transferred based on a wide electronic map such as an aerial photograph. The pattern analysis can be applied not only when an image such as an aerial photograph is used as an existing database, but also when an electronic map in a narrow sense such as a city map database is used as an existing database. In such a case, there is an advantage that a wide range of attributes in which symbols are not defined can be acquired by using pattern analysis.

  As mentioned above, although the various Example of this invention was described, it cannot be overemphasized that this invention is not limited to these Examples, and can take a various structure in the range which does not deviate from the meaning. For example, the above control processing may be realized by hardware in addition to software.

It is explanatory drawing which shows the structure of the electronic map data generation apparatus as an Example. It is explanatory drawing which shows the outline | summary of a database. It is explanatory drawing which illustrates the structure of the new road database 30a. It is a flowchart of an attribute setting process. It is a flowchart of a sidewalk attribute acquisition process. It is explanatory drawing which shows the condition where the misjudgment of the presence or absence of a sidewalk may arise. It is a flowchart of a separation zone attribute acquisition process. It is explanatory drawing which shows the judgment method of the presence or absence of a separation zone. It is a flowchart of an entry prohibition attribute setting process. It is a flowchart of a one-way attribute acquisition process. It is a flowchart of a one-way extending | stretching process. It is explanatory drawing shown about the extending | stretching process of an adjacent figure. It is explanatory drawing which shows the conditions of an extending | stretching process. It is a flowchart of a traffic stop attribute acquisition process. It is a flowchart of an elevated attribute acquisition process. It is explanatory drawing which shows the example of an item as a provision object of attribute information. It is explanatory drawing which shows the structure of 10 A of electronic map data generation apparatuses as a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10A ... Generation apparatus 11 ... Command input part 12 ... Database reference part 13 ... Polygon generation part 14 ... Result output part 15 ... Attribute setting part 15a ... Sidewalk setting module 15b ... Separation zone setting module 15c ... Intrusion prohibition setting module 15d ... One-way setting module 15e ... No-pass setting module 15f ... Elevated setting module 16 ... Pattern analysis unit 16
17 ... Pattern database 20 ... City map database 20A ... Aerial photograph 30a ... New road database 30 ... Road database

Claims (3)

A map database storing map data including links representing roads, nodes representing intersections of the links, and at least a part of the links, and road direction restriction information given as attribute information, and an input unit for inputting the data And a generation method for generating a new electronic map database by an electronic map database generation device comprising an information adding unit for adding attribute information to the link,
(A) the input unit inputting the map data from the map database;
(B) Based on the restriction information of the input map data and the connection state of the link, the unassigned link to which the traffic direction restriction information is not assigned constitutes a road having three or more roads. If it is one of the links,
(B1) A case where two links connected to both ends of the unset link via a node are both set links to which the restriction information is given, and the two set links have the same content (B2) The unset link is the same as any one of the set links existing at both ends of the unset link, and at least one of road type and lane number is the same (b3) When all the conditions that the angle formed between the unset link and any one of the set links existing at both ends of the unset link is equal to or less than a predetermined angle are satisfied with respect to the unset link A generation method characterized by executing a step of assigning restriction information given to a setting link as attribute information. The generation method according to claim 1, comprising:
The map database is configured as a unit drawing having a predetermined area, and for roads that cross adjacent unit drawings, a link is defined in each unit drawing by providing a node at the boundary of the drawing. And
In the step (b), for two links corresponding to roads that cross adjacent unit drawings, the regulation information given in one unit drawing is given to the link in the other unit drawing. Method. A map database storing map data including links representing roads, nodes representing intersections of the links, and at least a part of the links, and road direction restriction information given as attribute information, and an input unit for inputting the data And a generation device that generates a new electronic map database including an information adding unit that adds attribute information to the link,
The information giving unit
Based on the restriction information of the input map data and the connection state of the link, in a case where the unset link to which the restriction information in the traffic direction is not given is one of the links constituting a road of three or more roads,
(B1) A case where two links connected to both ends of the unset link via a node are both set links to which the restriction information is given, and the two set links have the same content (B2) The unset link is the same as any one of the set links existing at both ends of the unset link, and at least one of road type and lane number is the same (b3) When all the conditions that the angle formed between the unset link and any one of the set links existing at both ends of the unset link is equal to or less than a predetermined angle are satisfied with respect to the unset link A generation apparatus characterized in that the restriction information given to the setting link is given as attribute information.

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