JP2009204441A - Position information transmission method of digital map - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce errors in position specification on a receiving device side, to enable efficient position specification, and to enable efficient transmission/reception of position information between a transmitting device and the receiving device. <P>SOLUTION: A position information transmitting/receiving device 10 transmits coordinate row data including an object road section on the first digital map to a position information transmitting/receiving device 20 for specifying the object road section on the second digital map. When generating the coordinate row data, the position information transmitting/receiving device 10 extends the object road section up to a neighboring crossing, and fluctuates an extension distance equivalent to an extended distance of the object road section corresponding to a connection angle which is a crossing angle between at least two roads at the crossing. On the other hand, the position information transmitting/receiving device 20 receives the coordinate row data, and changes a range for retrieving a crossing corresponding to the second digital map according to a connection angle, when the connection angle which is the crossing angle between at least two roads at the crossing is included in the received coordinate row data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for transmitting position information on a digital map, and relates to a technique (location reference technique) for accurately transmitting a position on a digital map on a transmission device side on a digital map on a reception device side.

  In recent years, the number of vehicles equipped with in-vehicle navigation devices has increased rapidly. The navigation in-vehicle device maintains a digital map database, displays traffic jams and accident locations on a map based on traffic jam information and accident information provided by traffic information centers, etc., and adds such information to conditions Perform route search.

  There are many types of digital map databases on the market, and each map data contains errors due to differences in the base map and digitization technology, data conversion processing when the system is installed, etc. It depends on the digital map database. Therefore, for example, when the accident location is reported as traffic information, if the longitude / latitude data of the accident location registered on a certain map data is transmitted alone, the digital map database held in the navigation in-vehicle device is different from the transmission side. In this case, the position of the map may be shifted due to an error in the map, or a position on a different road may be identified as an accident position.

  In view of the above, conventionally, there is a method for transmitting position information of a digital map by defining a node number and a link number for nodes such as intersections existing in a road network on a digital map and links representing road sections between nodes. Was presented. However, since such a method requires a great deal of effort to update the digital map with the establishment or change of a road, the methods disclosed in Patent Document 1 and Patent Document 2 have been proposed.

  In the method of the above document, when transmitting position information, the transmitter transmits a road shape data representing a coordinate string of a road section of a predetermined length including an event position where an event such as a traffic jam or an accident has occurred, and a road section represented by the road shape data The event position data representing the event position is transmitted to the receiving side by the relative position in the receiver. The receiving device that has received the road shape data and the event position data performs position specification (shape matching) using the road shape data, specifies the road section on the digital map, and uses the event position data to determine the road section. The event occurrence position in is identified.

In the method of the above document, it is an important issue to improve the matching accuracy of the receiving device. Therefore, in Patent Document 3, when the transmitting device transmits a vector shape corresponding to the road shape data to the receiving device, a plurality of candidate points are unlikely to be generated when specifying the position on the receiving device side as end points of the vector shape. A location is selected, and a vector shape having end points at the location is transmitted to the receiving device.
JP 2001-041757 A Japanese Patent Application Laid-Open No. 2001-066146 JP 2002-328032 A

  In the above document, for example, when the start point or end point of a vector shape is close to an intersection, the start point or end point of the vector shape is extended to the intersection in advance on the transmission device side. The receiving device that has received the vector shape specifies the position on the digital map. However, since the intersection is designated as an end point in advance, a position specifying error (mismatching) is unlikely to occur.

  In general, the deviation of the position of the intersection on the digital map of each of the transmission device and the reception device is not so large. However, for connection points that connect gently, such as junctions, interchanges, and connecting roads at three-dimensional intersections (connection points of roads connected with a shallow connection angle), connect between the digital maps of the transmitter and receiver. There is a case where the position is shifted by a predetermined distance or more.

  When the transmission device selects the connection point as described above as the end point of the vector shape, the position of such a connection point may be greatly shifted between the digital map of the transmission device and the digital map of the reception device. In such a case, there is a possibility that the receiving apparatus cannot successfully find a point on the digital map corresponding to the end point of the vector shape.

  For example, as shown in FIG. 11, the digital map image (a) of the transmission device is different from the digital map image (b) of the reception device, and a superimposed image obtained by superimposing these two digital map images. Is shown in (c). In the superimposed image of (c), the digital map of (a) is indicated by a solid line, and the digital map of (b) is indicated by a dotted line. The area B existing on the digital map image of (a) and the area B ′ existing on the digital map image of (b) originally correspond to the same position, and the positions of these areas also on the superimposed image of (c). Is not significantly different.

  However, although the area A existing on the digital map image of (a) and the area A ′ existing on the digital map image of (b) originally correspond to the same position, the superposition of (c) On the image, the positions of these areas are greatly shifted. Therefore, when the transmission device selects a connection point existing in the area A on the digital map (a) as the end point of the road section, the reception device selects the connection point existing in the area A ′ on the digital map (b). There is a possibility that it cannot be found well.

  An object of the present invention is to provide a technique capable of solving the above-described problems and further improving the accuracy of position determination on the receiving device side.

  The present invention is a position information transmission method in which a transmission device transmits coordinate sequence data including a target road section on a first digital map to a reception device that identifies the target road section on a second digital map. In the process of generating the coordinate string data, the transmission device is configured to extend the target road section to a nearby intersection according to a connection angle that is an angle at which at least two roads intersect at the intersection. This is a position information transmission method that varies the extension distance corresponding to the distance that the road section is extended.

  With the above configuration, the transmission device can transmit coordinate sequence data that is unlikely to be erroneously specified on the reception device side in the vicinity of the intersection of the gentle connection angle, and changes the extension distance according to the connection angle. Therefore, unnecessary extension (which does not contribute to the improvement of the position specification on the receiving device side) can be prevented, the amount of transmission data can be minimized, and the burden on the transmitting device and the receiving device is reduced when transmitting the position information. It becomes possible to reduce.

  In addition, the present invention provides a position information transmission method in which a transmission device transmits coordinate string data including a target road section on a first digital map to a reception device that identifies the target road section on a second digital map. The transmission device, when generating the coordinate string data, assigns and transmits a connection angle of a road that intersects a reference point set in the target road section of the coordinate string data. It is a transmission method.

  With the above configuration, the transmission device can implicitly indicate the size of the search area where the reference point should be searched for to the reception device, and the reception device can prevent erroneous determination of the reference point.

  Furthermore, the present invention is a position information receiving method in which a receiving device receives coordinate string data indicating a target road section on a first digital map and specifies the target road section on a second digital map. The reception device receives the coordinate sequence data, and when the received coordinate sequence data includes connection angle information with a road that intersects at an intersection, the reception device corresponds to the connection angle of the connection angle information. A position information receiving method for changing a range for searching for a corresponding intersection on the second digital map.

  With the above configuration, it is possible to reduce position specifying errors in the receiving apparatus and to efficiently search for intersections.

  It is preferable that the receiving device expands a range for searching for the intersection along a longitudinal direction of the target road section.

  In addition, if you want to specify the intersection position in the middle of the target road section (to specify the position of the intersection), you will search for the corresponding intersection on the specified road segment, but the search range depends on the connection angle of the intersection road Therefore, it is possible to reliably find intersections with gentle connection angles that are likely to be far apart, while narrowing the search range at intersections that are close to a right angle as a whole. Can be avoided.

  With the above configuration, the receiving device can search for an intersection more efficiently.

  The present invention also includes a transmitting device that transmits the coordinate string data using the position information transmitting method and a receiving device that identifies a target road section on the second digital map using the position information receiving method.

  As described above, according to the present invention, it is possible to reduce position specifying errors particularly in the vicinity of intersections in the receiving apparatus, to enable efficient position specification, and to efficiently transmit and receive position information. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a position information transmission system including position information transmitting / receiving apparatuses 10 and 20 according to an embodiment of the present invention. Since each of the location information transmitting / receiving devices 10 and 20 exchanges location information with each other, both devices function as a (location information) transmitting device when transmitting location information, and when receiving location information ( Position information) Functions as a receiving device. Depending on the system, a configuration of a dedicated transmission device and a dedicated reception device may be considered. For example, the location information transmission device is a center device that provides a traffic information providing service, and the location information reception device is a car navigation system mounted on a vehicle. Device.

  In the digital map location information transmission (transmission / reception) method of the present invention, the transmission device selects a node at an end point by a predetermined method in order to prevent location specification errors (mismatching) on the reception device side.

  As shown in FIG. 1, the position information transmitting / receiving devices 10 and 20 include position information transmitting units 11 and 21, position information receiving units 12 and 22, digital map databases 15 and 25, position specifying units 13 and 23, Digital map display units 14 and 24, event information input units 16 and 26, and position information conversion units 17 and 27 are provided. Since the corresponding components between the position information transmitting / receiving apparatus 10 and the position information transmitting / receiving apparatus 20 are exactly the same, only the structure of the position information transmitting / receiving apparatus 10 will be described below.

  The position information receiving unit 12 receives position information including coordinate sequence data and event position data from the position information transmitting unit 21 of the position information transmitting / receiving apparatus 20 functioning as a position information transmitting apparatus. The digital map database 15 stores digital map data representing the first digital map. The position specifying unit 13 specifies the position of the position information (matching) on the first digital map using the coordinate sequence data and event position data of the position information received by the position information receiving unit 12. The digital map display unit 14 is constituted by a liquid crystal display device or the like, and displays display information generated by combining the position information and the first digital map as a result of the position specification by the position specifying unit 13. The digital map display unit 14 also displays event information input from an event information input unit 16 described later.

  The event information input unit 16 receives event information about events that have occurred such as traffic jams and accidents collected from various sensors arranged on the road, probe vehicles, and the like. The position information conversion unit 17 generates coordinate string data and event position data based on the event information input from the event information input unit 16. The position information transmission unit 11 transmits the position information including the generated coordinate sequence data and event position data to the position information reception unit 22 of the position information transmission / reception device 20 functioning as a reception device.

  FIG. 2 shows an example of position information generated by the position information conversion unit 17 and transmitted from the position information transmission unit 11. FIG. 2A shows coordinate sequence data composed of coordinate sequence information for specifying road sections, and FIG. 2B shows a relative position (path distance) from a reference point provided in the corresponding road section to an event position. Event relative position data). As will be described later, the coordinate string data in FIG. 2A includes connection angle information, which is information regarding the angle at which two roads intersect at an intersection.

  The coordinate string data (point list) in the present invention is an array of point data in which latitude and longitude are paired, but the number and contents of the point data are not particularly limited, and “dynamic position reference data” Are treated as

  In the case of the arrangement of coordinate points along the road, the more the number of such coordinate points, the closer the road shape is to the actual road shape. This is called road shape representation or Geometrey.

  In addition, the number of coordinates is small, and the shape may include data away from the actual road, and it is not always necessary to accurately trace the shape of the actual road.

  That is, it is only necessary that the points given according to the intersections and predetermined rules along the road can be connected (in terms of phase). Therefore, the position may be referred to by a single point or a plurality of points (for example, if there are two intersection points, a road section can be expressed by connecting the paths between them).

  Furthermore, although there are cases where these are combined, in the present invention, “coordinate string data” is used to include all of the above-described forms.

  Note that the connection angle information will be omitted if the node setting position is not an intersection, and there will be no connection road.If the connection angle is close to a right angle and therefore the error is estimated to be small, there is no need to explicitly indicate it. The amount of information can also be reduced.

  The position information conversion unit 17 acquires the coordinates (longitude / latitude) of the nodes p1 to pn of the road section including the event occurrence position from the digital map database 15 based on the event information input from the event information input unit 16. Coordinate sequence data is generated, a reference point is set in the target road section represented by the coordinate sequence data, and traffic information including relative distance data from the reference point to the event occurrence position is generated.

  When the position information conversion unit 17 generates the coordinate string information, the position information conversion unit 17 erroneously sets the node p1 or the node pn corresponding to the end point of the target road section serving as the start point or end point of position specification (matching) on the receiving device side. Choose so that matching (incorrect location) does not occur. That is, the position information transmission / reception device 10 that functions as a transmission device uses the coordinate string data indicating the target road section on the first digital map in the digital map database 15 included in the device 10 as position information transmission / reception that functions as a reception device. Transmit to device 20. The device 20 identifies the target road section on the second digital map in the digital map database 25. Since the first digital map and the second digital map may be different as in the digital map of FIG. 11A and the digital map of FIG. 11B, the selection of the node p1 or the node pn corresponding to the end point is selected. However, there is a method disclosed in Patent Document 3 described above. In such a method, when the end point of the original target road section is close to the intersection, the target road section is extended to a nearby intersection, and the end point is set as the intersection.

  For example, as shown in FIG. 3A, the position information transmitting / receiving apparatus 10 uses two roads as end points (start points) of coordinate sequence data indicating the target road section on the first digital map in the digital map database 15. Select a reference point that is the intersection of. Such a selection can be obtained by extending the target road section to the reference point even when the end point of the original target road section is not on the reference point.

  As illustrated in FIG. 3B, the position information transmitting / receiving device 20 that has received the coordinate string data specifies the target road section on the second digital map in the digital map database 25. As indicated by the dotted line in FIG. 3B, when the absolute coordinate shift between the first digital map and the second digital map is large, the location information transmitting / receiving device 20 may cause an incorrect matching of event occurrence points. is there. However, in this example, since a reference point that is an intersection is selected as the end point (start point) of the coordinate sequence data, the position information transmitting / receiving device 20 correctly specifies the location of the accident occurrence point based on the reference point. be able to. At this time, using the offset amount from the reference point obtained in advance from the position information transmitting / receiving apparatus 10 to the accident occurrence point, the position information transmitting / receiving apparatus 20 specifies the position of the accident occurrence point.

  That is, when the end point is an intersection, the intersection is a position easy to understand on the digital map (a position where a plurality of candidate points are unlikely to be generated), so even if the first digital map and the second digital map are different, In particular, it is unlikely that erroneous matching occurs on the receiving device side.

  However, as described above, two digital maps as shown in FIG. 11 (c) regardless of the corresponding positions such as the area A in FIG. 11 (a) and the area A ′ in FIG. 11 (b). If the position is greatly shifted between them, even if the transmitting device selects an intersection in the region A as an end point, the receiving device successfully finds a connection point existing in the region A ′ on the digital map in (b) You may not be able to. This is because the position information transmitting / receiving apparatus 20 may not search for the corresponding intersection up to the position of the area A ′ corresponding to the area A because the distance between the area A and the area A ′ is too large.

  The above-described positional shift phenomenon on the two digital maps is generally caused by two or more roads such as junctions, interchanges, connecting roads at three-dimensional intersections, etc., as shown in areas A and A 'of FIG. Is likely to occur gently at connection points (connection points of roads connected with a shallow connection angle). On the other hand, misalignment is unlikely to occur at intersections where two roads intersect at an angle close to a right angle, such as regions B and B '.

  On the other hand, the “extension of the road section to be transmitted” described so far increases the length of the target road section to be transmitted, and thus increases the amount of data and the processing load on the receiving apparatus side. It is desirable to narrow down to cases that are prone to misjudgment and minimize them to the minimum necessary.

  Therefore, in the present invention, the location information conversion unit 17 of the transmission device searches for an intersection (neighboring intersection) near the end of the target road section. Further, the position information conversion unit 17 examines the distance from the end of the original target road section to the neighboring intersection (end-to-intersection distance) and the connection angle that is an angle at which at least two roads intersect at the neighboring intersection. . Then, from the relationship between the predetermined connection angle and the extension distance, the position information conversion unit 17 determines whether or not to include the neighboring intersection in the target road section, that is, it corresponds to a distance for extending the target road section. The stretching distance is changed according to the connection angle. Specifically, as shown later (FIG. 9), when the connection angle is close to 90 degrees, the stretching distance is set short, and when the connection angle is close to 0 degrees or 180 degrees, the stretching distance is set long.

  That is, when the connection angle of neighboring intersections is close to 90 degrees, there is a high possibility that the deviation of corresponding neighboring intersections between two different digital maps is not large. Therefore, since it is considered that the necessity of selecting another intersection as an end point is small, the position information conversion unit 17 sets the stretching distance to be small and reduces the stretching frequency and distance. By such processing, the amount of data to be transmitted can be reduced.

  On the other hand, when the connection angle of neighboring intersections is close to 0 degrees or 180 degrees, the difference between corresponding neighboring intersections between two different digital maps is likely to be large. Therefore, since it is considered preferable to select the intersection as an end point, the position information conversion unit 17 sets the extension distance to be large and increases the extension frequency and distance. By such processing, it is possible to prevent erroneous determination on the receiving device side by clearly indicating the end point as an intersection in a place where the position shift is relatively large between two different digital maps.

  From the viewpoint of the relationship between the end-intersection distance and the extension distance described above, if the end-intersection distance for a specific neighboring intersection is smaller than the extension distance defined by the connection angle at the neighboring intersection, the neighboring intersection Is set at the end of the target road section.

  The position specifying unit 23 of the position information transmitting / receiving apparatus 20 as a receiving apparatus that has received the position information including the connection angle information varies the search range for searching for the end of the target road section according to the connection angle. The fluctuation of the search range here means that when searching for an end point on the position information transmitting / receiving apparatus 20 side, the range for searching the end of the target road section is not determined to be a predetermined distance (for example, 150 m), but at least two. According to the connection angle of one road, it is made to change so that it may become more than this predetermined distance.

  In the specific example of FIG. 3, the position information conversion unit 17 of the position information transmitting / receiving apparatus 10 checks the connection angle at the reference point that is the intersection of the two roads shown in FIG. Then, the position information conversion unit 17 stores the connection angle and the node number of the reference point to which the connection angle is assigned in the “connection angle information” of the coordinate sequence data illustrated in FIG. The position information transmitting unit 11 transmits the position information (FIG. 2) including the coordinate string data including the “connection angle information” in FIG. 2A and the event position data in FIG. .

  The position information receiving unit 22 of the position information transmitting / receiving device 20 receives the position information, and the position specifying unit 23 specifies the position of the coordinate string data in the position information on the second digital map of the digital map database 25 ( Matching). At this time, as shown in FIG. 4, the position specifying unit 23 searches a predetermined area, that is, a search area (SA) within a predetermined range from the absolute coordinates of the end points of the received coordinate string data. The intersection corresponding to the end point is searched for.

  Here, as a method of determining a search area, that is, a search range, as shown in FIG. 5, the connection angle θ of the connection angle information of the two roads at the intersection P of the two roads A and B in the received coordinate string data. Check. Alternatively, the connection angle θ ′ between the virtual road B ′ and the road A drawn with a line-symmetric relationship with respect to the other road A of the road B is checked (when 180 ° <θ <360 °). At this time, | θ | = | θ ′ |. When 0 ° ≦ θ ≦ 90 °, | θ | is used as the connection angle for determining the search range. When 90 ° ≦ θ ≦ 180 °, the connection angle for determining the search range is (180 ° − | θ |) Is used.

  Based on the connection angle, the position specifying unit 23 determines a search range using a correspondence table as will be described later (FIG. 9). That is, in general, when the connection angle is shallow (| θ |, (180 ° − | θ |) is small), the search range is expanded. An arbitrary search method may be used as appropriate. For example, the search range may be determined by multiplying a predetermined default value by P depending on a specific connection angle.

  Also, for efficient search, when expanding the search range, it is desirable to expand the search range along the longitudinal direction of the symmetrical road section. In the example of FIG. 4, the default search range SA has a circular shape, but since the connection angle is shallow, the search range with a length of SA × 1.5 is expanded in two fan shapes before and after the road. ing. In this example, the sector-shaped radius is SA × 1.5, the center angle is 60 °, and the center point is an intersection IP (Intersection Point) which is an end point of the transmitted target road section. The shape of the enlarged search range (enlarged search range) is not particularly limited, and an arbitrary shape such as an elliptical shape or a rectangular shape can be adopted.

  In addition, this method is not limited to the extension of the end point of the target road section and the search for the end point, but the reference point of the event occurrence position (for example, the accident occurrence position, the head / end position of the traffic jam, the road) The present invention can also be applied to a case where a reference point for clearly indicating the position of a POI (Point of Interest) outside the road is desired.

  That is, the transmission device can implicitly indicate the size of the search area in which the reference point should be searched for by giving the connecting point of the intersecting road to the reference point of the event occurrence position. The receiving apparatus can prevent erroneous determination of the reference point.

  For example, when a connection angle close to a right angle is given to the reference point, even when an intersection is found at a position slightly away from the reference point, the receiving device can identify that it is not a corresponding intersection but another intersection. it can. On the other hand, if a gentle connection angle is given, it can be identified as the same intersection even if the distance is somewhat

  In this case, since the identification of the road road segment is completed using the coordinate string data, the reference point is searched along the road on the identified road segment.

  FIG. 6 is a flowchart showing a procedure in which the position information transmitting / receiving apparatus 10 as the transmitting apparatus gives the connection angle information to the reference point described above, and particularly shows the operation of the position information converting unit 17. First, the location information conversion unit 17 superimposes event information, which is the source of the event location data shown in FIG. 2B input from the event information input unit 16, on the first digital map of the digital map database 15. Create location information including road segments. Then, the position information conversion unit 17 selects a target road section to be transmitted from the position information and picks up a reference point entertained in the target section (step S301).

  Next, the position information conversion unit 17 investigates whether or not an intersection road exists at each reference point from the reference point number 1 (step S302). When an intersection road exists at the reference point (step S303; YES), the position information conversion unit 17 gives a connection angle (information) (step S304). Furthermore, the position information conversion unit 17 confirms whether or not the survey for all reference points has been completed (step S305). If the survey has been completed (step S305; YES), the operation is terminated. If all the reference points have not been investigated (step S305; NO), the position information conversion unit 17 performs the operation of step S303 for the reference point of the next reference point number (step S306).

  In step S303, when the position information conversion unit 17 determines that no intersection road exists at each reference point (step S303; NO), the connection angle (information) is not given to the intersection road, and the determination after step S305 is performed. Done.

  FIG. 7 is a flowchart showing the operation of the position information transmitting / receiving apparatus 10 as the transmitting apparatus, and particularly shows the operation of the position information converting unit 17. First, the location information conversion unit 17 superimposes event information, which is the source of the event location data shown in FIG. 2B input from the event information input unit 16, on the first digital map of the digital map database 15. Create location information including road segments. Then, the position information conversion unit 17 selects a target road section to be transmitted from the position information (step S101).

  Then, the position information conversion unit 17 picks up an intersection existing outside the end point (start point or end point) of the target road section from the first digital map (step S102). Furthermore, the position information conversion unit 17 calculates the distance to the intersection and the connection angle of at least two intersection roads that intersect at the intersection (step S103).

  Thereafter, the position information conversion unit 17 determines whether or not to include the intersection in the target road section according to the distance and the connection angle (step S104). When the intersection is not included in the target road section (step S104; NO), the end point of the target road section remains the same as the original target road section selected in step S101 (step S105). When the intersection is included in the target road section (step S104; YES), the target road section is extended to the intersection and a new target road section is set (step S106). Further, the position information conversion unit 17 creates position information (FIG. 2) corresponding to the coordinate string data of the target road section, and the position information transmission unit 11 transmits the position information to the position information transmission / reception device 20 as a receiving device. To do.

  FIG. 8 is a flowchart showing the operation of the position information transmitting / receiving apparatus 20 as a receiving apparatus, and particularly shows the operation of the position specifying unit 23. First, after the position information receiving unit 22 receives the position information from the position information transmitting / receiving device 10 (step S201), the position specifying unit 23 performs the process for each node included in the target road section of the coordinate string data of the position information as shown in FIG. It is confirmed whether or not the connection angle information described in (a) is given. The position specifying unit 23 determines whether or not connection angle information is assigned to the nodes in order from the node number = 1 (step S202) (step S203). When the connection angle information is given (step S203; YES), the position specifying unit 23 sets the search range of the position (intersection) on the second digital map of the digital map database 25 corresponding to the node as the connection angle. It is determined according to (step S204). When the connection angle information is not given (step S203; YES), the position specifying unit 23 uses a default value that is a value set in advance as a search range (step S205).

  Thereafter, the position specifying unit 23 searches for the corresponding intersection on the second digital map within the search range determined in step S204 or step S205 (step S206). If the search has not been completed for all nodes (step S207; NO), the operations from step S203 to S206 are repeated for the next numbered node (step S208). After the search is completed for all nodes (step S207; YES), the position specifying unit 23 combines the position information and the second digital map of the digital map database 25 to generate display information, and the digital map display unit 24 Displays the display information.

  FIG. 9 shows a correspondence table used when the position information transmitting / receiving apparatus 10 changes the extension distance according to the connection angle at the intersection in step S104 of FIG. When the connection angle is 60 degrees or more, the stretching distance is 50 m, when the connection angle is less than 60 degrees and 20 degrees or more, the stretching distance is 150 m, and when the connection angle is less than 20 degrees, the stretching distance is 300 m.

  FIG. 10 shows a correspondence table used when the position information transmitting / receiving apparatus 20 determines a range for searching for an intersection according to connection angle information in the coordinate sequence data in step S203 of FIG. If there is no connection angle information (step S205 in FIG. 8), the default value of 150 m is used. If connection angle information exists (step S204 in FIG. 7), the search range is determined according to the table. When the connection angle is 60 degrees or more, the search range is 50 m, when the connection angle is less than 60 degrees and 20 degrees or more, the search range is 150 m, and when the connection angle is less than 20 degrees, the search range is 300 m. As shown in FIGS. 9 and 10, the stretch distance and the search range have the same value at the same connection angle, but it is not always necessary to take the same value at the same connection angle.

  As described above, according to the present invention, the end point search range in the receiving device is changed and the extension distance in the transmitting device is changed according to the connection angle of the intersection. Accordingly, it is possible to reduce the position specifying error on the receiving apparatus side, to enable efficient position specifying, and to efficiently transmit and receive position information between the transmitting apparatus and the receiving apparatus.

  Although various embodiments of the present invention have been described above, the present invention is not limited to the matters shown in the above-described embodiments, and those skilled in the art can make modifications and applications based on the description and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.

  The present invention provides a technique for accurately transmitting a position on a digital map, particularly in a system for transmitting position information on a digital map.

Block diagram of a position information transmission system including a position information transmitter / receiver Data structure diagram of location information Conceptual diagram of matching when the end point of the target road section is selected as an intersection Conceptual diagram showing the search range of endpoints Conceptual diagram explaining the connection angle Flow chart showing operation of transmission device Flow chart showing operation of transmission device Flow chart showing operation of receiving apparatus Table showing the relationship between connection angle and extension distance Table showing search range according to connection angle Conceptual diagram explaining the difference in node position between two digital maps

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20 Position information transmission / reception apparatus 11,21 Position information transmission part 12,22 Position information receiving part 13,23 Position specification part 14,24 Digital map display part 15,25 Digital map database 16,26 Event information input part 17,27 Location information converter

Claims (7)

A position information transmission method in which a transmission device transmits road shape data including a target road section on a first digital map to a reception device that identifies the target road section on a second digital map, wherein the transmission The device
When generating the road shape data, the target road section is extended to a nearby intersection,
According to a connection angle that is an angle at which two roads including at least the target road intersect at the intersection, the extension distance corresponding to the distance at which the target road section is extended is changed.
Location information transmission method. A position information transmission method in which a transmission device transmits road shape data including a target road section on a first digital map to a reception device that identifies the target road section on a second digital map, wherein the transmission The device
When generating the road shape data, a connection angle of a road that intersects a reference point set in the target road section of the road shape data is given and transmitted.
Location information transmission method.   A transmission apparatus that transmits the road shape data using the position information transmission method according to claim 1. A receiving apparatus is a position information receiving method for receiving road shape data indicating a target road section on a first digital map and specifying the target road section on a second digital map, wherein the receiving apparatus includes: ,
Receiving the road shape data;
When the received road shape data includes connection angle information with a road that intersects at an intersection, a corresponding intersection on the second digital map is searched according to the connection angle of the connection angle information. Change the range
Location information reception method. The position information receiving method according to claim 4,
The receiving apparatus is a position information receiving method for expanding a range for searching for the intersection along a longitudinal direction of the target road section. The position information receiving method according to claim 4,
The position information receiving method in which the receiving device changes a search distance range of the intersection according to a connection angle of a connection road when searching for the position of the intersection existing on the identified road section. A receiving device for specifying a target road section on the second digital map using the position information receiving method according to claim 4.

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