JP5561915B2 - Map drawing apparatus and program - Google Patents

Description

  The present invention relates to a technique for receiving map data and drawing a map using the received map data.

In recent years, with the development of information processing technology and wireless communication technology, information communication processing that can be connected to a network such as personal computers, portable personal information terminals (hereinafter referred to as PDA (Personal Digital Assistant)), mobile phones, car navigation systems, etc. The use of devices is progressing.
In particular, in recent years, with the development and popularization of GPS (Global Positioning System) and various sensor technologies, the information communication processing device currently exists and its surrounding information are superimposed on the map on the information communication processing device display device. There are an increasing number of services to provide.
For example, in a car navigation system, the position of a car on which a terminal device of the car navigation system is mounted is acquired from a GPS system, the current position of the car is superimposed on a map and displayed, route guidance to a destination, It provides facility search services for restaurants and hotels around the current location. Similarly, similar services are being developed in PDA (registered trademark) and mobile phones.

Conventionally, in a car navigation system, data relating to a map to be drawn (hereinafter referred to as map data) is stored in a terminal device such as an HDD (Hard Disk Drive), a CD-ROM (Compact Disk Read Only Memory), and a DVD (Digital Versatile Disk). All the data is stored in the capacity storage device, and the necessary map data is acquired from the large capacity storage device and processed as necessary.
However, since the map data that exists in the mass storage device of the terminal device is used, for example, a new road was opened, a conventional road was abandoned, a convenience store was newly opened, etc. The factor that changes the map that occurred after the date and time when the map data was created is not reflected. Therefore, if the map data is used as it is for a long time, a system problem such as displaying a map different from the actual situation or guiding a route that does not actually exist occurs.
Therefore, companies that provide car navigation systems often provide map data update services to terminal users of car navigation systems on a regular basis to solve the above problems.
However, in order to receive the update service, the conventional update service has to temporarily store the HDD in the terminal device at the service provider side, or purchase the update data and the user needs to perform the update work. There are challenges.
In addition, there are many cases in which the update data is provided at intervals of once every six months or once a year, and there is a problem that it is not possible to cope with changes occurring during that time.

Therefore, recently, taking advantage of the fact that it can be connected to the network, research is being conducted to enable the terminal device to access the map server that manages the map data via the network and acquire the update data of the map. Some services have begun.
Since this method can update map data via the network, the user need not leave the HDD at the service provider side or go to a store to purchase updated data, and can update to the latest map data at any time. There is an advantage that you can.

As another solution, a method for realizing a car navigation system by storing only map data necessary for processing by the terminal device via a network without storing the map data on the terminal device side has been studied. Since this method does not require a large-capacity storage device to be mounted on the terminal device, the terminal device can be provided at low cost, and the map data side does not need a function of providing differential update data to each terminal device. As long as the map data managed in the site is the latest.
However, since the terminal device does not always hold the map data, the map data cannot be acquired when it cannot be connected to the network, and there remains a problem that the system does not function as a system.
The reason why it becomes impossible to connect to the network is that if a communication device that relies on batteries for power, such as a mobile phone, is used as a device to connect to the network, the network infrastructure will install a base station because the connection will not be possible due to a shortage of batteries It is not a problem that can be ignored in areas that are not connected, such as being unable to connect due to failure of the network infrastructure itself, and so on.

  When it becomes impossible to connect to the network, the terminal device needs to perform processing only with the map data that was acquired before the connection could not be made, but the area where map data could not be acquired was processed, especially as a map on the screen display device. If there is a case where it must be drawn, there is a problem that processing cannot be performed. Conventionally, the area is drawn in the actual acquisition area so that the system user can recognize that the map data of the area has not been acquired. I used to draw images and warnings that were not easily mistaken for maps.

FIG. 28 shows an example in which a region corresponding to unacquired mesh data is displayed on a display device.
In a situation where a map of an area on the display device is being drawn, an area in which the corresponding map data has been acquired in the drawing area is generated based on the information, and a map 801 is displayed to display line information. The road 802 is drawn based on the above. In addition, attribute information such as road names and intersection names may be displayed based on the point information.
Next, when an area for which map data acquisition has not been completed exists in the drawing area, the conventional technique cannot draw a map of that area. In that case, no drawing process is performed in the drawing area 803 corresponding to the unacquired area, a certain color is applied, a specific pattern image is laid out, and a message 804 in which map data cannot be acquired is drawn. And other alternative drawing processes.

  However, in such a drawing method, the user cannot know the map of the unacquired area at all, and there remains a problem that impairs convenience.

In order to solve such problems, various solutions have been studied.
One is a technique for displaying a map of an area where map data is not acquired by using data other than the map data held by the terminal device.
For example, in Patent Document 1, when the terminal device performs route guidance to a certain destination, if the guidance route passes a route for which no road data exists, the drawing is performed assuming that there is a road on the route. It becomes possible.
Further, in Patent Document 2, when the travel locus information stored in the terminal device is used and there is travel locus information in an area where no road data exists, the travel locus information is used as road data to draw a road. Is possible.

In addition, there is a technique for displaying a map of an area that has not been acquired by using the data corresponding to an area for which map data has not been acquired when a part of the data has been acquired.
For example, in Patent Document 3, when there is no partial enlarged map information of a region designated for drawing and map information corresponding to a scale different from the scale designated for display can be acquired, the scale is different. It is possible to draw a map of an area where map data cannot be acquired using map information.
JP 2002-350167 A Japanese Patent Laid-Open No. 05-274592 JP-A-10-293534

However, with these methods, the problem cannot be dealt with when alternative information corresponding to an area where data to be originally used cannot be acquired has not been acquired.
Specifically, in Patent Document 1, even if the guide route can be displayed as a road, if the user deviates from the route or if route guidance is not being performed, the interpolation display ahead is performed. There is a problem that it cannot be done.
Moreover, in patent document 2, in the case of the area | region without the last traveling locus information, there exists a subject that a road cannot be displayed by interpolation.
Moreover, in patent document 3, there exists a subject that the interpolation display cannot be performed with respect to the area | region without the map data of a different scale.

The present invention has been made in view of such problems, and there is alternative information corresponding to the position of information that cannot be acquired when a part of data that should be originally used when drawing a map cannot be acquired. Even if not, the main purpose is to provide geographical information about the area to the user.
In addition, the system to be applied is not limited to the car navigation system, but may be another information processing apparatus represented by a mobile phone, a PDA (registered trademark), etc. It may be in other fields such as pedestrians, athletes, public transportation systems, and space equipment.

The map drawing apparatus according to the present invention is:
A map drawing device that receives map data in mesh units from a map data management device that manages map data including road displays in mesh units, and draws a map based on the received map data,
When the map data of at least a part of the map data to be transmitted from the map data management device cannot be received, the retained map data held by the map drawing device is analyzed and a specific mesh is analyzed. A road extraction unit for extracting a road related to the specific road displayed in the holding map data;
A map drawing unit for drawing a map for displaying the specific road and the related road extracted by the road extracting unit;
The specific road and the related road are connected via a missing mesh from which map data could not be received from the map data management device between the mesh from which the related road was extracted and the specific mesh. And a notification information generating unit that generates notification information for associating the specific road with the related road when the map drawing unit cannot draw a map indicating a state.

  According to the present invention, when map data of a part of meshes cannot be received, a related road related to a specific road is extracted from the retained map data, and the specific road and the related road are intervened by a missing mesh. Even when a divided map is displayed, by associating a specific road with a related road, information can be provided to the user that the related road related to the specific road exists elsewhere. it can.

In the first to sixth embodiments, a map drawing device that receives map data in units of meshes from the map data management device and draws a map based on the received map data will be described.
More specifically, when map data of some meshes cannot be received, retained map data retained by the map drawing device (map data newly received from the map data management device, retained previously) (Including both map data) and extract roads (such as roads with the same name) related to specific roads (such as roads on which the vehicle is currently traveling) displayed in a specific mesh from the retained map data When a specific road and the extracted related road are displayed and a map showing the state where the specific road and the related road are connected cannot be drawn due to a missing mesh from which map data could not be received, A map drawing apparatus for associating a specific road with a related road and notifying a user will be described.
Further, in the seventh embodiment, matters that are the premise of the operation of the map drawing apparatus described in the first to sixth embodiments, such as a map data management method, a map data transmission / reception sequence, and a map drawing method, will be described.

Embodiment 1 FIG.
FIG. 1 is a schematic block diagram of a map drawing system including the map drawing device and the map data management device shown in the first to sixth embodiments.
The map drawing system includes a map drawing device 1201 that outputs a map based on map data, and a map data management device 1301 that manages the map data.
The map drawing device 1201 and the map data management device 1301 can be connected by a network, and any network may be used. In the first to sixth embodiments, a mobile phone or a wireless LAN (Local Area) is used. A network capable of realizing wireless communication such as (Network) is assumed.
However, it may be a network that supports only a wired system.

  In FIG. 1, one map drawing device 1201 and one map data management device 1301 are shown, but the number of map drawing devices 1201 and map data management device 1301 is not necessarily one, and there may be a plurality of each. Further, the map data management apparatus 1301 may be configured with a plurality of servers for the purpose of load distribution and the like, and may be a virtual server that is disclosed as a single virtual server on the network.

  The map data management device 1301 manages map data in units of meshes, map data for each mesh is stored in a storage device, and map data can be searched for each mesh based on a request from the map drawing device 1201. The map data can be transmitted to the map drawing device 1201 for each mesh.

The map drawing device 1201 is arranged on a moving body, for example. More specifically, for example, it is mounted on a vehicle or possessed and mounted on a user.
The map drawing device 1201 includes at least a central control device 1202, a map storage device 1204, a communication device 1205, and a map output device 1206.

The central controller 1202 controls the entire map drawing process.
The communication device 1205 is means for connecting to the map data management device 1301 via a network and acquiring map data.
The map storage device 1204 manages map data acquired from the map data management device 1301 and information necessary for processing.
The map output device 1206 outputs the map created by the central control device 1202 using the map data stored in the map storage device 1204 and the map data acquired from the map data management device 1301.
In addition, a position detection device 1203 for acquiring the current position of the map drawing device 1201 as necessary, an operation panel 1207 for the user of the map drawing device 1201 to operate, a voice output device 1208 for outputting a voice message, and the like are provided. It doesn't matter.
Note that the map output device 1206 is an example of a display unit, and the audio output device 1208 is an example of an audio output unit.

The map storage device 1204 is an area for temporarily storing map data acquired from the map data management device 1301.
The central control device 1202 internally manages mesh data to be drawn and information associated therewith, but stores other mesh data not yet drawn that have been acquired in the map storage device 1204. The purpose is to make the central control unit 1202 obtainable as necessary.
The communication device 1205 acquires map data to the map data management device 1301 via the network.
The map output device 1206 is, for example, a CRT or a liquid crystal display, and displays a map as an image.
In addition, text data generated by the central controller 1202 based on the map data may be displayed on a CRT, a liquid crystal display, or the like.
The voice output device 1208 outputs a voice message generated by the central control device 1202 based on the map data as a voice through a speaker or the like.
Further, the map output device 1206 and the sound output device 1208 may output a combination of a plurality of map images, sounds, and texts.

In the present embodiment, when the map drawing device 1201 cannot acquire a part of mesh data that should be originally used when performing map output, there is no alternative information corresponding to mesh data that cannot be acquired. Even so, a method for providing geographical information about the area to the user will be described.
That is, depending on the network conditions, the map drawing device 1201 may not be able to acquire all requested map data, and may not be able to acquire all of the requested map data.
For example, when a network failure occurs during map data acquisition and communication between the map drawing device 1201 and the map data management device 1301 is not possible, or when a mobile phone network is used for the network, the map drawing device 1201 uses it. If the mobile phone that is in use falls short of power and becomes unable to communicate, or if it becomes impossible to accept a request from the map drawing device 1201 due to a failure in the communication processing system of the map data management device 1301, map data management There are cases where the device 1301 has received a request exceeding the allowable number and cannot return a response to the map drawing device 1201, or the server function is down due to a malfunction in the processing system of the map data management device.

Therefore, in the present embodiment, when the map drawing device 1201 cannot acquire all necessary map data, the geographical information is “whether the road currently moving or stationary is in the direction in which the unacquired mesh exists. Is there a possibility that this is the situation? ""What kind of situation" here means how far the road continues, in which direction it may be bent, there is a possibility of turning, there are multiple roads of the same type and number Continuity of roads, continuation direction, shape, number, possibility of connection, etc., whether there is a possibility of connecting to other roads and in what order Can be mentioned.
Moreover, the change of the information expression according to the reliability of those information is also included. For example, if it can be confirmed that there is a road of the same type and number ahead, it will be provided as definitive information. For example, information may not be provided.

  The outline of the operation of the map drawing apparatus 1201 according to the present embodiment will be described with reference to FIG.

First, the map drawing device 1201 requests the map data management device 1301 to transmit map data necessary for drawing the map (S1001).
Then, the map drawing device 1201 receives the map data transmitted from the map data management device 1301 (S1002).
The details of the map data requesting step (S1001) and the map data receiving step (S1002) will be described in Embodiment 7 with reference to FIG.

Next, the map drawing device 1201 determines whether there is an unacquired mesh (missing mesh) that could not be received in the map data received from the map data management device 1301 (S1003).
If there is no unacquired mesh (NO in S1004), the map drawing device 1201 draws a map using the map data received from the map data management device 1301 and the map data held in the map drawing device 1201 (S1005). ) By outputting the drawn map (S1006), the user can refer to the map.

On the other hand, when there is an unacquired mesh (YES in S1004), the map drawing device 1201 extracts a related road related to a specific road from the held map data held (S1007).
The retained map data includes both map data newly received from the map data management device 1301 and map data stored in the map storage device 1204 from before.

Here, the specific road is, for example, a road where the user is currently located or a road designated by the user. The related road is, for example, a road having the same type and name as a specific road (hereinafter also referred to as the same road), or a road having a name but a similar attribute (hereinafter also referred to as a heterogeneous road). is there.
A road having the same name and type as a specific road (same road) is a road to which the same name (national road ○ line) is given when the specific road is a national road ○ line.
Also, a road with a different name but having a similar attribute to a specific road (heterogeneous road) is a national road when the specific road is a national highway ○, but the name of the road is different as in the national highway △. This is the case when the road attributes are the same, or when the road attributes are not the same as in the prefectural road × line, but the road attributes are similar. Further, the administrator of the map drawing device 1201 can determine the similar range of road attributes. For example, in the case of car navigation applications, it is conceivable to classify national roads, prefectural roads, expressways, toll roads, and automobile-only roads that are regarded as main roads as different roads.

In step S <b> 1007, the map drawing device 1201 determines whether a map showing a state where a specific road and a related road are connected can be drawn.
For example, when related roads are the same road, if a map with the same name is divided on the way due to intervening unacquired meshes, the specific road and the related road are connected. It is not a state.
Also, for example, when the related road is a heterogeneous road, for example, the national road No. ○ that is a specific road changes from a specific position to the national road No. Δ, but the road is the same road and only the name changes When the map becomes such that the national highway No. ○ and the national highway Δ are divided on the way due to the intervening mesh, the specific road and the related road are not connected.
Further, for example, when the related road is a heterogeneous road, the specific road and the related road intersect (intersection by intersection, intersection by three-dimensional intersection) from the positional relationship and direction of the specific road and related road. If a certain road is estimated to branch into multiple roads including related roads, or if a specific road is estimated to merge with related roads, In the case of a map in which a specific road and a related road are divided, the specific road and the related road are not connected.

Next, the map drawing device 1201 draws a map using the map data received from the map data management device 1301 and the map data held in the map storage device 1204 (S1008).
In addition, when it is not possible to draw a map showing a state where a specific road and a related road are connected because an unacquired mesh is interposed between a specific mesh that includes a specific road and a mesh from which the related road is extracted Generates notification information for associating a specific road with a related road (S1009), and outputs a map and notification information (S1010). The notification information is also referred to as unacquired area status information.

For example, as shown in FIG. 8, map data can be acquired between a mesh showing a user's current position 1704 and a road 1705 where the user is located and a mesh showing a road 1706 having the same name as the road 1704. In the case where a map with the roads 1705 and 1706 connected to each other cannot be drawn due to the unacquired unacquired mesh, the map drawing device 1201 indicates that both the road 1705 and the road 1706 have the same name (the national highway ○ line) Notification information 1707 to 1709 for notifying that both roads are continuous is generated, and notification information 1707 to 1709 is output together with the map.
As a result, the user can grasp the outline that the national highway No. ○ continues for a while and turns to the right.

In the first to fourth embodiments, the same road of a specific road is extracted as a related road, and notification information for notifying that the specific road and the extracted same road are the same road is generated and output.
In addition, the example which extracts a heterogeneous road as a related road is demonstrated in Embodiment 5 or later.

FIG. 3 shows functional blocks executed by the central controller 1202 of the map drawing device 1201 according to the first to sixth embodiments.
FIG. 3 shows a minimum configuration necessary for explaining the operation of the map drawing device 1201 according to Embodiments 1 to 6, and a configuration other than that shown in FIG. 3 may be included.

  In FIG. 3, an input unit 1211 is means for inputting data from a device external to the central control device 1202. For example, data indicating a user instruction is input from the operation panel 1207, data indicating the current position of the map drawing device 1201 is input from the position detection device 1203, or transmitted from the map data management device 1301 from the communication device 1205. Map data is input, or map data to be displayed is input from the map storage device 1204.

  The output unit 1212 is a means for outputting data to a device external to the central control device 1202. For example, map drawing data and notification information are output to the map output device 1206, or notification information in audio format is output to the audio output device 1208.

  The map data request unit 1213 requests the map data management apparatus 1301 to transmit map data necessary for drawing the map. Details of the map data request procedure are as shown in FIG.

The road extraction unit 1214 determines whether or not there is an unacquired mesh (missing mesh), and if there is an unacquired mesh, analyzes the retained map data and relates to a related road related to the specific road displayed in the specific mesh. To extract.
Note that the road extraction unit 1214 extracts a related road that is divided from a specific road due to the non-acquired mesh and is not drawn in a state of being connected to the specific road.

  The map drawing unit 1215 draws a map to be displayed on the map output device 1206 using the map data received from the map data management device 1301 and, if necessary, the map data stored in advance in the map storage device 1204. .

The notification information generation unit 1216 identifies the map based on the related road extracted by the road extraction unit 1214 when a map indicating a state in which the specific road and the related road are connected via an unacquired mesh cannot be drawn. Notification information for associating a road with a related road is generated.
Specifically, as shown in FIG. 8, notification information for notifying that the same road extracted by the map drawing unit 1215 and a specific road (the road at the current position of the user) are the same road is generated. .

FIG. 4 shows that when at least part of mesh data that should be originally used when performing map output is not acquired, even if there is no alternative information corresponding to mesh data that cannot be acquired, the user FIG. 4 is a flowchart of a specific processing method for providing geographical information regarding the area.
This processing group shows details of the processing of S1003, S1004, and S1007 of FIG.
By performing the process of FIG. 4, it is possible to tell the user what situation the road corresponding to the current position is in the direction of the unacquired mesh depending on the presence or absence of mesh data that is necessary but has not yet been acquired. It can be provided as information.

First, in process S301, the road extraction unit 1214 determines whether there is mesh data that is currently acquired and has not yet been acquired.
In this determination process, it is checked whether mesh data corresponding to a set of mesh identifiers exists in the display target mesh list of the basic management information, and whether or not it is in an acquisition complete state, and even one corresponding mesh data does not exist. Alternatively, if there is a mesh list that is not in the acquisition completion state, it is determined that there is unacquired mesh data.
The basic management information is information shown in FIG. Details of each piece of information shown in FIG. 30 including basic management information will be described in the seventh embodiment.
Details of the mesh identifier and the display target mesh list will also be described in the seventh embodiment.

  Next, when the road extraction unit 1214 determines that there is no unacquired mesh data as a result of the determination in step S301, the road extraction unit 1214 ends this processing and immediately proceeds to mesh data drawing processing. In the mesh data drawing process, the map drawing unit 1215 draws a map.

Conversely, if it is determined that there is unacquired mesh data, the road extraction unit 1214 executes step S303.
In the map storage device search process S303, the road extraction unit 1214 searches all mesh data stored in the map drawing device 1201 at that time.
Next, the road extraction unit 1214 executes the adjacent acquisition completion mesh set A calculation process S304.
In this process S304, the road extraction unit 1214 combines the acquisition completion mesh data stored in the basic management information with the acquisition completion mesh data searched in process S303, and sets the adjacent mesh data as one set. Form.

FIG. 5 is a diagram illustrating a mesh whose mesh data has been acquired at a certain time point and other positional relationships.
A white mesh means that the mesh data acquisition has not been completed or is not an acquisition target, and a shaded mesh means that the acquisition has been completed.
According to this processing S304, adjacent acquisition completion mesh data is formed as one set, so that sets 1501, 1502, and 1503 are formed as such sets.
The adjacency relationship of the acquired mesh data can be determined as the absolute value of the difference between the X component or Y component of the mesh identifier of the mesh data is 0 on one side and the mesh that is 1 on the other side is adjacent. .
Further, the case where the absolute value of the difference is 1 for both the X component and the Y component may be considered.
Therefore, it is searched whether the mesh data corresponding to the newly generated mesh identifier exists in the acquisition completed mesh data by adding or subtracting 1 from the X component or Y component of the identifier of the acquisition completion mesh data. In such a case, these mesh data are determined as elements belonging to the same adjacent acquisition completion mesh set. If this is executed for all acquisition completion mesh data, all adjacent acquisition completion mesh sets can be obtained.

  In the following, for the purpose of explanation, the adjacent acquisition completion mesh set 1501 in FIG. 5 is referred to as a set A1, the adjacent acquisition completion mesh set 1502 is referred to as a set A2, and the adjacent acquisition completion mesh set 1503 is referred to as a set A3.

Next, the road extraction unit 1214 executes a boundary mesh set B calculation process S305 of each adjacent acquisition completion mesh set A.
In this process S305, the road extraction unit 1214 generates a boundary mesh set B composed only of meshes that are adjacent to the unacquired area, from each of the adjacent acquisition completed mesh sets generated in process 304.
FIG. 6 shows the result of obtaining the boundary mesh set for the sets A1, A2, and A3 in FIG.
A boundary mesh set corresponding to the set A1 is a set 1601, a boundary mesh set corresponding to the set A2 is a set 1602, and a boundary mesh set corresponding to the set A3 is a set 1603.

Whether the mesh is a boundary mesh can be determined as mesh data of a boundary mesh when at least one non-acquired mesh data exists in meshes adjacent to mesh data that is an element of the acquisition complete mesh set.
Conversely, when mesh data corresponding to all adjacent meshes has been acquired, it is not an element of the boundary mesh. Each boundary mesh set can be obtained by executing this determination processing for all of the elements for every adjacent acquisition completion mesh set.

Next, the road extraction unit 1214 executes a process S306 for deriving the moving road C at the current position.
This process S306 uses the current position acquired by the position detection device 1203 to use the map matching technique often used in the conventional car navigation system, and performs the process of matching the current position to the road on the map. It is.

Next, the road extraction unit 1214 executes a process S307 for searching for the road D that is the same road as the road C from each set B.
In this process S307, a road having the same attribute as the road C is searched from all the boundary mesh sets B. The same attribute is determined by, for example, whether the road name, road type, and road number match.
As a specific example, if the road C is the national highway 30, the road type is the national road and the road number 30 is the search condition.
In addition, for example, when road information to be contacted is described in an attribute included in point information indicating a road, the determination may be made based on whether the information and the road C match.
The determination criteria may be changed according to the determination criteria for the same road. For example, the road thickness attribute may be used as the determination criterion when the determination criterion for the same road is included when the road thicknesses match.
An example of a specific search method will be described with reference to FIG.

First, the road extraction unit 1214 selects one boundary mesh set from the set of boundary mesh sets in step S401, and selects one mesh data from the set.
Next, in step S402, the road extraction unit 1214 stores point information indicating roads of the same type and number as the road C included in the boundary mesh set selected in step S401 (hereinafter, the same road). Prepare.
Next, in process S403, one mesh data is acquired from the boundary mesh set selected in process S401.
Next, in the determination process S404, it is determined whether or not unprocessed point information indicating a road for which the main search process is not performed exists in the mesh data selected in the process S403. If it exists, the process S405 is performed, and if it does not exist, the process S408 is performed.

In step S405, one piece of unprocessed point information indicating a road is extracted from the mesh data selected in step S403.
Next, in determination process S406, it is determined whether the point information selected in process S405 and road C are the same road.
If it is determined that the road is the same, step S407 is performed. If it is determined that the road is different, step S404 is performed.

In process S407, the point information determined to be the same road in process S406 is added to the same road list created in process S402. By performing this processing, it becomes possible to store all the point information of the same road for the road C existing in one boundary mesh set (point information of the end points in the boundary mesh of the road) in the same road list. .
In addition, in step S407, the point information of the same road of road C is stored in the same road list for a certain boundary mesh. This means that the same road and road C extracted in the boundary mesh have an unacquired mesh in between. This means that the road is not drawn as a continuous road (only roads that are divided by the unacquired mesh can be drawn).

In step S408, if there is no point information indicating a road that has not been processed in step S404, it is determined whether there is unprocessed mesh data in the boundary mesh set selected in step S401.
If there is mesh data that has not been processed, step S403 is performed, and the same same road search process is performed on the mesh data that has not been processed.
If there is no mesh data that has not been processed, it is found that the search processing for all mesh data in the currently selected boundary mesh set is complete, and the process proceeds to step S409.
Finally, the process S409 is executed when the search process for one boundary mesh set is completed. Here, it is determined whether there is a boundary mesh set that has not been processed in the set of boundary mesh sets. In order to perform the same road search process for the remaining unprocessed boundary mesh set, the process S401 is executed.
If not, since the processing for all the boundary mesh sets has been completed, this processing ends here.

Returning to the description of the processing in FIG.
The processing S307 described here is processing for searching the road D from each boundary mesh set B, but the search set may be each adjacent acquisition completion mesh set A.
By using the adjacent acquisition complete mesh set A, it is also possible to provide information on acquisition complete meshes that are not adjacent to unacquired meshes that cannot be detected by the boundary mesh set B.
Further, although one identical road list is created for all boundary mesh sets in step S402, there may be a case where no same road exists depending on the boundary mesh set.
In such a case, the process S402 is not necessary.
Therefore, the process S402 may be executed only when it is determined in the process S406 that the boundary mesh set is the same road for the first time.

Finally, in process S308, the notification information generation unit 1216 performs generation processing of unacquired area status information (notification information) based on information related to the same road as the road C searched in process S307.
In the conventional map display device, when there is unacquired mesh data, information indicating that an unacquired area exists is output as shown in FIG.
However, according to the present embodiment, since it is possible to obtain information on whether or not the same road as the currently located road exists in the boundary mesh set, the information can be provided.

A specific method for generating notification information will be described with reference to FIG.
As a premise, it is assumed that the current position of the user is located at the position 1605 and the road 1604 is moving.
At that time, it is assumed that the notification information generation unit 1216 refers to the same road list generated in S407 of FIG. 7 to find that the boundary mesh set 1603 includes the same road 1606 as the road 1604.
One method for generating notification information is to generate an image as an image.
The map drawing device 1201 has a function of outputting a map image based on the map data. Using this function, the notification information generation unit 1216 generates and outputs an image that associates the current position 1605 and the currently traveling road 1604 with the same road 1606 detected from the same road list as notification information.
For example, a display area 1607 is a minimum area in which a mesh including the current position and a mesh including the same road 1606 are included at the same time.
When displaying the map in the display area 1607, the notification information generation unit 1216 generates an image associating the current position 1605 and the currently traveling road 1604 with the same road 1606 as notification information, and the map drawing unit 1215 draws the map. If the image is superimposed on the map and output, for example, an outline map image 1701 as shown in FIG. 8 can be generated.

At least an area display 1702 indicating a mesh area that has not been acquired, a current position 1704, a road 1705 that is currently running, and a road 1706 that is determined to be the same road as the road 1705 are drawn on the overview map image 1701. Other roads and other information described in the map data may be selected and displayed.
Then, as the notification information, arrows 1708 and 1709 are displayed for associating the currently traveling road 1705 with the road 1706 determined to be the same road, and “national road” indicating that the road 1705 and the road 1706 are the same road. A character string 1707 “O-Line” is displayed.
These notification information can clearly indicate that the road 1705 and the road 1706 are the same road.
Since the same road list generated in S407 of FIG. 7 stores point information of the same road for each boundary mesh, the notification mesh information generation unit 1216 displays the boundary mesh indicated in the same road list as a display area. When included in 1607, the same road of the boundary mesh can be associated with the road that is currently running.

Note that the arrows 1708 and 1709 in FIG. 8 do not have to be arrows, but may be straight lines, curved lines, or dotted lines, and any display method can be used as long as it can visually read that the character string 1707 and the roads 1705 and 1706 are related. Absent.
Also, the character string 1707 may have different contents, may display data in a different format such as an image instead of the character string format, and can display anything common to the roads 1705 and 1706 visually. It may be in the form.

Here, the area display 1702 is desirably drawn by the same drawing method as that used when the map drawing device 1201 displays a mesh area that has not been acquired during normal map display.
For example, when the acquisition area is expressed in gray only in the normal process, if the area display is displayed in the same color, the user can also determine the meaning of the area from the color.
However, they do not have to be the same, and different drawing methods such as a method of not telling the user that there is an unacquired area by drawing in the same color as the background color of the area in which the roads 1705 and 1706 are drawn. It does not matter. The area display 1702 may be indicated by a character string 1703 in order to explicitly indicate that the map data has not been acquired. The content of the character string 1703 may be different, or the character string 1703 may be displayed in a data format of a different format such as an image.

Next, as a method for outputting the generated outline map image to the map output device 1206, for example, a method of displaying the outline map image using all the output possible areas of the map output device 1206 can be considered.
In this case, only the outline map image is displayed on the map output device 1206, and the others are not displayed.
In addition, a method of displaying only the outline map image even in a part of the output possible area is conceivable. Moreover, when displaying a summary map image in a part of output possible area | region, the method of displaying another information in the area | region which does not display a summary map image is also considered.
For example, when a map around the current position is being output to the map output device 1206 as shown in FIG. 9, a method of superimposing a summary map image as shown in FIG. A method of superimposing the current position so that it is not hidden behind the outline map image, or dividing the screen as shown in FIG. 12 and displaying the map display and the outline map image in different areas can be considered.

As another specific information generation method, a method of displaying it as a character string or voice can be considered.
For example, when the notification information generation unit 1216 extracts the same road 1606 from the same road list, “From now on, the map data cannot be acquired. The national road No. ○ currently running may be in another area. Notification information in a linguistic expression such as “confirmed” may be generated, and the notification information may be output to the audio output device 1208 to notify the user that the same road 1606 exists.
In addition to images, character strings, and voices, information may be notified in other formats. Not only these may be used alone, but information may be notified in multiple formats such as a combination of images and voices. .

  Thus, according to the present embodiment, when map data of at least some meshes cannot be received, the same road of the currently running road is extracted, and an unacquired mesh is interposed to Even when a map is displayed in which the road is divided from the same road, the same road on the currently running road can be found in another location by associating the same road with the currently running road. Information can be provided to users.

As described above, in the present embodiment, the map data of the area adjacent to the area where the map data cannot be acquired (hereinafter referred to as the unacquired area) is changed to the unacquired area on the road that is not currently traveling on the same road as the currently traveling road. He explained how to search for an approaching road and to provide information to the user that there is a road of the same type as that of the traveling road in another place.
Then, when a road of the same type as the road that is currently traveling enters an unacquired area, information is provided to the user where the same type of road is located elsewhere (for example, unacquired) It is possible to provide information by displaying the same kind of road as the currently running road around the area as a schematic map on the screen (without displaying other roads).

In addition, as a method for determining the background color of the unacquired area, the map drawing device uses the main color of the unacquired area in the normal map display or the approximate map display (the color most frequently used to draw the area or similar to it) The system color is determined from the main colors of the adjacent acquisition completion regions.
This makes it easy to understand the boundary by setting the colors of the non-acquired area and the acquisition completed area to be close colors, making the boundary difficult to understand. It becomes.
In addition, when there are a plurality of unacquired areas, it is possible to draw by changing to a color close to a nearby color each time the place is moved.

Embodiment 2. FIG.
The method described in the first embodiment is a method of searching for the same road as the currently running road and notifying information only when the same road exists.
In the present embodiment, a method for deriving the positional relationship between the same road and the currently traveling road will be described.
By implementing this method, it becomes possible to notify the user which direction and distance the same road is located, and it is possible to notify a more specific positional relationship.
The overall system configuration and the internal configuration of the map drawing device 1201 are the same as those shown in FIGS.

FIG. 13 is an example of a flowchart relating to a specific method for deriving the positional relationship between the current road and the same road. The operation subject in FIG. 13 is a notification information generation unit 1216.
Moreover, the process of FIG. 13 is performed during the process of S308 of FIG. 4, for example.

In process S501, the notification information generation unit 1216 determines a representative point of the traveling road.
This representative point is a coordinate used as a parameter for deriving the positional relationship between roads together with the representative point of the same road obtained in step S502 described later.
Since a road is not a point but a line having a length, the result may differ depending on which position on the road is used as a reference, and there are various methods for determining a representative point. For example, the position of point information where the road is in contact with the unacquired mesh or point information and coordinates in the vicinity thereof may be used, or the current position may be used if the road is running.
In the present embodiment, the representative point of the traveling road is a point where the traveling road is in contact with the unacquired mesh in the traveling direction. Here, if there are a plurality of pieces of point information that satisfy this condition, the point is closest to the current position.

Next, in process S502, the notification information generation unit 1216 determines a representative point of the same road.
In the present embodiment, the representative point of the same road is the point information position where the same road is in contact with the unacquired mesh. Here, when there are a plurality of pieces of point information that satisfy this condition, the point is the point closest to the representative point of the traveling road determined in step S502.

In step S503, the notification information generation unit 1216 generates vector information from the representative point of the traveling road to the representative point of the same road.
The absolute direction of the representative point of the same road viewed from the representative point of the traveling road can be obtained by the ratio of the X component and the Y component of the vector. Further, this vector may be normalized.
As a specific method for determining the direction, for example, when the direction is indicated by east, west, south, and north, a method of uniquely mapping using the X component of the vector, the positive or negative of the Y component, and the ratio thereof may be considered.

  Finally, in process S504, the notification information generation unit 1216 calculates the distance between the representative points, and derives the distance of the same road as the traveling road.

Then, the notification information generation unit 1216 generates unacquired area status information (notification information) based on information on the same road as the road C including the direction and distance information obtained as a result of the above processing. I do.
For example, it is conceivable to output direction and distance information as notification information together with the outline map image. FIG. 14 shows a specific example thereof, and direction and distance information 1801 is overwritten on the outline map image of FIG.
In addition, the notification information generation unit 1216 may output the line 1802 connecting the representative points so that the specific distance can be understood.
The auxiliary line 1802 is a dotted line, but may have other shapes such as a solid line and a curved line.
When the direction and distance information 1801 is output at the same time, the direction and distance information 1801 is output on the auxiliary line 1802 in order to prevent the direction and distance information 1801 from being hidden by the auxiliary line 1802. It doesn't matter.
Further, as shown in FIG. 14, since the feature is not displayed in the unacquired area, the line 1802 connecting the representative points can be clearly shown to the user.

Further, the unacquired area status information may be in the form of characters or sound instead of an image, or information may be output using them in combination.
For example, a voice message saying “You will soon be in an area where map data cannot be obtained. The road you are currently driving will continue to the east is more than 5 kilometers away” will be displayed as an overview map image. It is conceivable to display the information with the direction and distance information 1801 deleted from FIG.

As another specific method, a method using a mesh identifier can be considered.
Since the mesh identifier of the present embodiment uses coordinates representing the positional relationship with the reference mesh, the direction can be obtained by generating a direction vector from the mesh identifier of the mesh to which each road belongs. Further, since the size of the mesh is constant, the distance between the meshes can be obtained by using the mesh identifier and the size.

  Further, regarding the auxiliary line 1802, the actual data is visually referred to by taking a drawing method different from the non-estimated road drawn based on the line information (the road drawn as a map with reference to the actual data). It may be possible to notify that the road is different from the drawn road.

  Thus, according to the present embodiment, in addition to associating the current road with the same road, the distance between the current road and the same road, the same road with respect to the current road Since the user is notified of the location direction, more information can be provided to the user.

As described above, in the present embodiment, the map drawing device is currently traveling based on the position information where the currently traveling road enters the unacquired area and the position information where the searched same road enters the unacquired area. The generation of geographical relative information with the roads in the country was explained.
And by this, when providing information that there is a road of the same kind as the road that is currently traveling in another place, the road that the other road is currently traveling, the direction based on the absolute position, The distance between the two roads can be provided as information (for example, “There are 1.2 kilometers northeast of the same type of road that is currently running”, voice output, and the direction and distance are also displayed on the map) Become.

Embodiment 3 FIG.
In this embodiment, the shape of the road that connects the currently running road and the same road is estimated using the direction vectors of the currently running road and the same road, and the estimated estimated road shape is An embodiment for notifying the user will be described.
In the method described in the second embodiment, the positional relationship between two roads is derived using the representative point or mesh identifier of the road between the two roads, and the information is output.
However, it does not consider what direction the two roads are facing.

For example, when the currently traveling road 1901 shown in FIG. 15A and the same road 1902 are detected, and when the currently running road 1903 shown in FIG. 15B and the same road 1904 are detected. In the method according to the second embodiment, the same processing is performed even if there are some differences in distance and positional relationship.
However, in order to connect to the road 1902 from the road 1901 shown in FIG. 15 (a), it cannot be connected unless at least a right turn is made, but in order to connect to the road 1904 from the road 1903 shown in FIG. There is a difference that it is possible to connect in a straight line, and it is desirable to output information explicitly to the user.
For example, when the map drawing device 1201 is included in the car navigation system, watching the screen while traveling is also prohibited in the traffic route law and is dangerous, so the driver looks at the screen of the car navigation system during normal driving. I can't do that.
Therefore, even if it is output in voice output, such as “The road you are currently driving is going to be east more than 5 kilometers away”, it is an absolute direction, so you should go straight ahead on the road you are currently driving. It is difficult to determine if there is a possibility of bending.
Therefore, in the present embodiment, it is necessary to indicate whether the same road exists in a relative direction using the difference in the traveling direction between the roads as a reference, based on the current traveling direction. FIG. 16 is a flowchart thereof, and is executed, for example, in step S308 of FIG.

First, the notification information generation unit 1216 obtains a direction vector that represents the traveling direction of the road in step S601.
Unless the road is one-way, it can travel in both directions, so two direction vectors can be created.
Therefore, in the present embodiment, using the fact that the two roads to be processed are roads connected to the unacquired area, the starting point and the ending point of the vector are obtained by the following method.
1) The starting point of the vector is a constituent point adjacent to a constituent point that is an end point of a position entering the unacquired region, among constituent points of line information representing the road.
2) The end point of the vector is a constituent point that is an end point of a position that enters the unacquired region among constituent points of line information representing a road.
For example, in FIG. 15A, the start point of the direction vector of the road 1901 is a constituent point 1905, the end point is a constituent point 1906, the start point of the direction vector of the road 1902 is a constituent point 1907, and the end point is a constituent point 1908. In FIG. 15B, the start point of the direction vector of the road 1903 is the constituent point 1909, the end point is the constituent point 1910, the start point of the direction vector of the road 1904 is the constituent point 1911, and the end point is the constituent point 1912.

In the next process S602, the notification information generation unit 1216 obtains an angle formed by the vectors obtained in process S601.
There are two ways of expressing the angle generated by the two vectors. As shown in FIG. 17, the calculated angle is obtained by translating the start points of the two vectors so as to have the same coordinates, and the direction vector of the currently traveling road. Is a vector 2001, and the direction vector of the same road is a vector 2002. This angle is in the range of -180 degrees to 180 degrees. If the same road vector is on the left side of the direction vector of the traveling road, the angle that can be generated is a negative value. If the same road vector is on the right side, the angle is a positive angle.

Next, in process S603, the notification information generation unit 1216 generates a half line extending in the vector direction. Specifically, a half line parallel to the vector is generated with the end point of the vector as the end point.
FIG. 18 illustrates half straight lines 1913, 1914, 1915, and 1916 of roads 1901, 1902, 1903, and 1904.

In process S604, the notification information generation unit 1216 determines whether or not an intersection can be formed between half straight lines on the same road as the currently traveling road generated in process S603.
In FIG. 18A, the half lines 1913 and 1914 are parallel and do not intersect, but in the half lines 1915 and 1916 in FIG. 18B, there is an intersection 1917. If there is an intersection, the process S606 is processed, and if there is no intersection, the process S605 is processed.

The process S605 is a process of generating information that substitutes for an intersection when the half lines do not intersect with each other, and an auxiliary line is used to generate information that serves as an alternative.
There are two possible causes of the non-intersection of two half lines, as shown in FIG. 19A. As shown in FIG. 19A, one half line is parallel to the other and as shown in FIG. 19B. Since the other is not parallel, it intersects if it is a straight line, but may intersect on the side where the half line is cut. However, since it is not essentially different, the same processing is performed as follows.

The notification information generation unit 1216 generates a vector from the end point of the half line of the currently traveling road to the end point of the half line of the same road, and this is called an end point vector.
The inter-endpoint vector is generated in order to examine which direction the road is directed to based on the road in the current traveling direction when the road is linear between the end points.
The notification information generation unit 1216 translates the start point of the inter-endpoint vector so as to match the start point of the direction vector of the currently traveling road, and obtains a possible angle. When the angle is −90 degrees or more and 90 degrees or less, it can be determined that the road is not in the direction opposite to the traveling direction when a road is drawn between the end points. For this reason, it is determined that the roads are connected by connecting the positions of the point information of the locations in contact with the unacquired areas of both roads.

A specific method for generating unacquired area status information when step S606 is executed after this determination will be described.
The current road is connected to the same road, but it turns gently when the angle between the endpoint vector and the direction vector of the current road is small, but when the angle is somewhat large, the current road The road may have undergone a sudden turn. For example, a determination method using a table as shown in FIG.
For example, when the status information of the unacquired area is generated by a character string or voice by this determination, for example, “The area where map data could not be acquired soon will be entered. It is highly possible that it will continue up to a kilometer away. "
The left / right judgment can be determined to turn right when the angle is negative and to turn left when the angle is positive.

Next, the case where it produces | generates as an image is demonstrated.
One example of a method of reflecting the road situation as shown in FIG. 20 also when an auxiliary line between two roads is drawn in the image will be described with reference to FIG.

First, the notification information generation unit 1216 draws a line segment 1920 connecting the end point 1918 of the currently traveling road and the end point 1919 of the same road, and obtains an intermediate point 1921 thereof.
Next, when the direction vectors are parallel, the notification information generation unit 1216 draws a straight line 1922 that passes through the intermediate point 1921 and is orthogonal to the road direction vector, and the half road 1923 of the currently traveling road Points 1925 and 1926 intersecting with the straight line 1924 are obtained.
Next, the notification information generation unit 1216 obtains an intermediate point 1927 on the straight line 1922 between the points 1925 and 1921 and an intermediate point 1928 on the straight line 1922 between the points 1921 and 1926.
In the case of FIG. 19B in which the direction vectors are not parallel, the straight line 1922 cannot be drawn under the above conditions. In this case, the notification information generation unit 1216 draws a straight line 1922 as a straight line orthogonal to the direction vector of the currently traveling road.
Finally, the notification information generation unit 1216 displays a curve that smoothly passes through the points 1918, 1927, 1928, and 1919 as an auxiliary line.
When this method is used, the rate of change of the curve increases in accordance with the size of the generated angle, so that a situation close to FIG. 20 can be reproduced on the image. However, this method is merely an example, and the shape of the auxiliary curve may be determined by other methods.

  Next, processing when the angle is −180 degrees or more and less than −90 degrees or greater than 90 degrees and equal to or less than 180 degrees will be described.

In this case, if there is a road between the end points, it can be determined that the direction vector is opposite to the direction vector of the currently traveling road.
Therefore, it is determined that the same road as the currently traveling road is not connected at the end points but is connected in the opposite direction to the direction vector of the currently traveling road.
In the next process S606, it is generated as unacquired area status information that the same type of road is running in parallel.
For example, when generating status information of an unacquired area with a character string or voice, for example, “Enter the area where map data could not be obtained soon. It is also in the place of the meter. "And so on, it generates only information that it exists without using the connected expression.
In the above processing, -90 degrees or 90 degrees is a decision branch point of whether or not to connect, but if it is actually 90 degrees, the road must be bent at 90 degrees at the end point. So it's not so realistic. Therefore, the angle that becomes the branch point may be changed between −90 degrees and 90 degrees.

  As described above, in the present embodiment, the shape of the road connecting the currently running road and the same road and the relative direction of the same road are estimated, the estimated road shape is presented, and the user's progress Since notification information indicating which direction (relative direction) the same road is based on the direction is generated, the user can be notified of the estimated shape of the road in the unacquired mesh, and the user Can notify the direction of the same road in a format that is easy to grasp.

As described above, in the present embodiment, for the method for estimating the shape of the traveling road in the unacquired area, the direction vector in which the currently traveling road enters the unacquired area and the direction in which the searched same road enters the unacquired area When a vector intersects in an unacquired area, the map drawing device forms a road shape in the approximate unacquired area by drawing a curve at the intersection and the position where two roads enter the unacquired area. Explained to provide as information.
In addition, this makes it possible to visually provide information about the direction in which the road running in the unacquired area is curved.

  Further, regarding the method for estimating the shape of the traveling road in the unacquired area, the direction vector in which the currently traveling road enters the unacquired area and the direction vector in which the searched same road enters the unacquired area are the unacquired areas. In the case where the map does not intersect, the map drawing device uses the auxiliary line to create the estimated road composing point, to form the road shape in the approximate unacquired area, and to provide it as information.

Also, regarding the distinction between the estimated display and the actual map display, the map drawing device has visually different characteristics such as shape and color from the road on which map data is drawn below when displaying the approximate road shape on the screen. I explained to display.
This makes it easy for the user to clearly distinguish and recognize the approximate road shape in the unacquired area from the actual road.

Embodiment 4 FIG.
In the embodiments described so far, the description has been made assuming that there is always one identical road.
Here, a case where the same road does not exist and a case where a plurality of the same road exist will be described.

  First, a processing method when the same road does not exist will be described.

  If the same road is not found in step S307 in FIG. 4, the notification information generation unit 1216 displays the currently running road on the screen as shown in FIG. 22, for example, while displaying the name of the road. , "I will enter the area where map data could not be obtained soon. You can not judge the situation ahead of the national road ○ currently driving, please drive referring to the road guidance." It is conceivable that notification information that suggests traveling without relying on the map display device is generated and notified to the voice output device 1208 while notifying the distinguishable name of the road.

Further, when there is a boundary mesh set other than the one that includes the currently traveling road, the road extraction unit 1214 includes the most current position among the meshes included in the boundary mesh set. A method is also conceivable in which the one close to the mesh is selected, the main road closest to the current position is searched as the related road in the mesh, and the notification information generation unit 1216 notifies the existence thereof.
The determination method of the main road is based on information included in the attribute of point information representing the road, such as whether the road type is a national road, the thickness of the road, the number of lanes, and the like.
For example, as shown in FIG. 23, the currently running road, the main road 2001 selected in the above process and its name 2002 are displayed on the screen, and the direction in which the main road 2001 exists as an image is output. It is possible to notify the direction and the approximate distance, such as “Enter the area where map data could not be acquired soon. There is a national highway △ route 4 kilometers ahead in the left direction” with notification information by voice. The distance may be displayed on the screen.
The distance between the currently traveling road (National Route ○ in Fig. 23) and the related road (National Route △ Route in Fig. 23), the related road (National Road in Fig. 23 △) to the currently traveling road (National Route ○ in Fig. 23) For example, the calculation method of the location direction of the (line) is based on the method described in the second embodiment.

  Next, a specific processing method when there are a plurality of the same roads will be described.

When there are a plurality of the same roads, when notification information for notifying all of them is generated, there is a high possibility that the user will have difficulty in judgment because there is too much information.
Considering such a situation, the simplest method when there are multiple identical roads is to select the same road closest to the current position from the multiple identical roads and reject the others. It is done.
When this method is implemented, the processing described so far can be used as it is.
In this case, the process S402 of FIG. 7 is executed before S401, and the same road list is used for all boundary meshes. In step S407, if point information is already registered in the same road list, it is determined which of the registered point information and the point information to be registered is closer to the current position, and the closer one is the same road list. Will be registered with.

In the above change, the process S402 is moved before the process S401. However, by not moving, it is possible to acquire only the same road that is closest to the boundary mesh set.
In this case, when the situation information is generated as an image, the smallest rectangular display that includes all meshes that include the same road closest to the current position and the mesh that includes the current position in each boundary mesh set. Set as an area and generate an image.

FIG. 24 is a specific example of an image generation result that is status information when only the same road closest to each boundary mesh set is acquired.
The same roads 2102 and 2103 closest to each other in the boundary mesh set are displayed together with the currently traveling road 2101. Similarly to the images described so far, the name 2104 of the currently traveling road is displayed, and arrows 2105, 2106, and 2107 are displayed for the corresponding road.
Further, in this example, the same road closest to the current position is extracted, and the auxiliary line 2109 and the approximate direction and distance 2108 between the same road closest to the current position are displayed using the method described so far. .
In this example, the auxiliary line 2109, the approximate direction, and the distance 2108 are displayed only on the same closest road, but may be displayed on a plurality of the same road.
In that case, a method of taking out one from all the same roads in order and applying and displaying the methods described so far can be considered.
Further, when the current position is closer to the same road than the current position, a method of applying and displaying the method described so far with one as the currently traveling road and the other as the same road may be considered.
In addition, when generating notification information by voice or character string, for example, “It will enter the area where map data could not be obtained soon. The same road as the current driving road has been found in two places. It is about 1 kilometer to the north, and the other is about 5 kilometers to the east. "

  As described above, in the case where the same road as the currently running road cannot be extracted, and in the case where a plurality of the same roads as the currently running road are extracted, it is possible to appropriately provide information to the user.

As described above, in the present embodiment, when a plurality of identical roads are found by searching for a processing method when a plurality of identical roads (roads with the same name) exist, the map drawing device determines the distance between the two roads. It is explained that the combination that is most likely to be connected is determined based on the angle formed by the approach direction vector, the intersection, the presence / absence of an intersection between the estimated road shapes, and the information is provided as information.
Thus, even when there are a plurality of identical roads, it is possible to determine where there is a high possibility of connection.

In addition, regarding the processing method in the case where the same road (the road with the same name) does not exist, when the same road is not found as a result of the search, the map drawing device provides that as information.
As a result, it is possible to provide information that the road that is currently running in the unacquired area is interrupted.

Embodiment 5 FIG.
In the processing method described so far, a specific method of processing for generating information expressing the situation between the same road and the currently traveling road has been described.
The purpose of this is to efficiently notify the user of the current road condition in the future.
However, in an actual road, for example, a location that becomes National Route B often appears at an intersection where National Route A exists. Therefore, simply explaining the situation with the same road may not provide information explaining the situation.
Therefore, in this embodiment, a method for determining the possibility of connection with a different road will be described.

First, considering the essential difference between the same road and different roads, it is possible that the same road meets the criteria for the same road set by the system, and that the roads that do not meet it are different roads. .
However, there will be an infinite number of roads that do not satisfy the criteria, and if all different roads are processed as the same road in the method described so far, the processing load will be very high, Not realistic.
Therefore, for heterogeneous roads, the system sets the heterogeneous road processing criteria for determining whether it is worth performing the determination, and only for the heterogeneous roads that satisfy the conditions, the same road in the method described so far Take the way to do the processing.
As described above, roads having similar road attributes can be considered as different roads. For example, in the case of car navigation applications, national roads, prefectural roads, highways, toll roads, automobiles that can be regarded as main roads. It is conceivable to classify dedicated roads as different roads.

FIG. 25 is a processing flow in which a heterogeneous road extraction process to be processed is added to FIG. 7 using a heterogeneous road process determination criterion.
In the added process, a process S410 for generating a list for storing different types of roads to be processed is added between the process S401 and the process S402.
In addition, a process S411 for determining whether the point information determined as different roads in the same road determination satisfies the different road processing determination criterion is added.
If the determination criterion is not satisfied even in step S411, the process proceeds to step S404. If the determination criterion is satisfied, the process proceeds to the newly added process S412. In step S412, the point information satisfying the different road processing determination criterion is registered in the different road list.
In step S412, the point information of the different road of the road C is stored in the different road list for a certain boundary mesh because the different road and the road C extracted in the boundary mesh are intervened with an unacquired mesh. This means that the road is not drawn as a continuous road (only roads that are divided by the unacquired mesh can be drawn).

When the processing shown in FIG. 25 is completed, point information representing the road to be processed is stored in the heterogeneous road list.
Therefore, if the notification information is generated by the method described so far by treating the roads stored in the heterogeneous road list as the same road, the heterogeneous roads that may be connected to the currently running road may be displayed. It becomes possible.

FIG. 26 shows an image generation example when a heterogeneous road list is generated based on the processing of FIG. 25, the possibility of connection is also determined for different roads stored in the list, and notification information is generated as an image.
In FIG. 26, the same road 2203 and the heterogeneous road 2202 as the currently running road 2201 are displayed.
In order to indicate that the same road 2203 as the currently traveling road 2201 is the same road, the road name 2204 and arrows 2205 and 2207 showing the relevance are displayed.
Further, in order to indicate that the different road 2202 is a different road, an arrow 2206 indicating the relationship with the road name 2210 is displayed.
In this example, as a result of analyzing the positional relationship between the different road 2202 and the same road 2203 with respect to the currently traveling road 2201, the different road 2202 is closer to the currently traveling road 2201 than the same road 2203. An approximate direction, a distance 2208, and an auxiliary line 2209 are displayed.

In FIG. 26, the dissimilar road 2206 is closer to the traveling road 2201, so the auxiliary line 2209 and the approximate direction and distance 2208 are connected to the dissimilar road. However, as shown in FIG. The distance 2208 may be connected to the direction.
In this case, the auxiliary line 2209 may be handled as a currently traveling road, and the connection possibility determination process with the different road 2202 may be performed.
That is, the notification information generation unit 1216 analyzes the positional relationship using, for example, the method described in Embodiment 4, and determines whether or not there is a possibility that the heterogeneous road 2202 is connected to the auxiliary line 2209 (guessed road). If there is a possibility that the dissimilar road 2202 may be connected to the auxiliary line 2209 (guessed road), it is notified that the dissimilar road 2202 may be connected to the currently traveling road 2201 via the auxiliary line 2209 (guessed road). Notification information to be generated may be generated and output.
In that case, for example, if you want to generate notification information by voice, “You will be in an area where map data could not be obtained soon. The road you are currently driving continues to the east for about 5 kilometers. There is a possibility that the national highway △ line may be connected ”, the possibility of connecting different roads may be added to the information.
When outputting as an image, an auxiliary line may be newly drawn from the heterogeneous road 2202 toward the auxiliary line 2209 and added as information.
Similarly, when there are a plurality of different roads, auxiliary lines may be drawn from a plurality of auxiliary roads.
Also, when generating the notification information by voice, “You will be in an area where map data could not be obtained soon. The road you are currently driving continues to the east for about 5 kilometers away. After that, there is a possibility of connecting to the national highway x route ", you may add information in the order of connection.

As described above, according to the present embodiment, since the possibility of connecting to a different road in addition to the same road is determined, the user can be notified of the possibility of connecting to a different road.
Further, by searching for a road that is likely to be connected to the speculated road, it is possible to notify the user of the future prospect of the currently traveling road.

As described above, in the present embodiment, regarding the connection possibility determination method for different types of roads, an approach vector of a road entering an unacquired area and an unacquired area of the currently traveled road among roads different from the currently running road It has been explained that the map drawing device provides the information to the user when the approach vector to the vehicle intersects.
This provides information on the possibility that the road currently running in the unacquired area will be connected to a different road (such as "Notice that there is a possibility of connecting to the National Road No. ) Can be done.

In addition, regarding the method for determining the possibility of connecting different types of roads, if the estimated road shape in the unacquired area of the currently running road intersects with the approach vector to the unacquired area of the different road, the map drawing device uses that Explained that the information is provided to the person.
As a result, the estimated road shape is used to determine the possibility of connection between the currently traveling road and different roads, so that a wide range of estimation is possible.

In addition, regarding the information presentation method when there is a possibility of connection with a plurality of different roads, if it is determined that there is a possibility that a plurality of different roads and a currently traveling road are connected, the map drawing device Information presentation explained that the intersections with different roads are presented in order from the closest to the road that is currently running.
This makes it possible to present a plurality of different road connections in chronological order.

Embodiment 6 FIG.
Here, the timing at which the processing described so far is executed will be described.
The map drawing device 1201 shown in the first to fifth embodiments displays a map while moving the display target range in accordance with the movement of the user, and the processing (related roads) shown in the first to fifth embodiments. Extraction and generation of notification information) basically do not need to be executed except when unacquired mesh data enters the display target range.
Therefore, one is a method of starting the processing described in the first to fifth embodiments when a mesh corresponding to unacquired mesh data enters the display area.
In addition, a method of starting the processing described in the first to fifth embodiments when a non-acquired mesh is included in a mesh corresponding to a fixed range around the display target range is conceivable. In this case, specifically, a method is conceivable in which scanning lines are provided at a fixed distance around the display target region, and the process starts when a mesh corresponding to unacquired mesh data touches the line.

As another method, there is a method that starts when the currently traveling road advances in the traveling direction and touches the mesh corresponding to the unacquired mesh data, and there is no intersection between the points touching the current position. Conceivable. In this case, it is determined that the area corresponding to the unacquired mesh data must be displayed when the road is advanced in the same direction as the current one.
In addition, a method of starting when there is an explicit request from the user is conceivable.
By having this method, it is possible to obtain the status information when the user wants to know at any time when connected to the unacquired area.
If the current road does not enter the unacquired area at that time, information indicating that the information does not enter the unacquired area is generated and output.
Moreover, you may make it start the process shown in Embodiment 1-5, when arbitrary timings in the above-mentioned several timing are combined and it becomes any timing.

In the present embodiment, with regard to the activation timing, when the current position touches the unacquired area, the road existing at the current position is acquired as the traveling road.
As a result, the system can be automatically activated when the current position touches the unacquired area.

In addition, when the current position approaches within a certain distance from the non-acquired area, the start timing is determined as the road that is in the current position and the road that is in contact with the non-acquired area Explained that it is treated as a road.
As a result, the system can be automatically activated when approaching a certain distance to the unacquired area.

As for the start timing, if the road that exists at the current position is connected to the unacquired area when proceeding in the direction of travel, and there is no intersection between the current position and the entry position to the unacquired area, the road Explained that the part that touches the unacquired area is treated as a road that is currently running.
As a result, when it is found that the vehicle is entering the unacquired area when the current traveling is maintained regardless of the distance, it can be automatically activated.

In addition, with regard to the activation timing, it has been explained that when there is an explicit request from the user, the currently running road is processed as the currently running road.
Thereby, when the user wants to know, it becomes possible to know the situation when connected to the unacquired area.
In addition, when there is an explicit request from the user, it can be provided as information that the road that is currently running does not enter the unacquired area.
As a result, when the user wants to know, it is possible to know that the currently traveling road does not enter the unacquired area.

Embodiment 7 FIG.
Next, the premise of operation | movement of the map drawing apparatus 1201 demonstrated in the above Embodiments 1-6 is demonstrated below.

* Difference between map and map data A map is a map of the entire surface of the earth or a part of it, scaled to a certain scale and illustrated using symbols and characters. In general, roads, railroad tracks, buildings, rivers, mountains, and other features are described on the map, and information such as road names, intersection names, signs, and facility names is added according to the purpose of use. Thus, what is described on the map is generically called an entity.
Maps are usually drawn on paper and are intended for human use. However, since it is difficult to handle with information processing equipment such as a car navigation system in the state described on the paper, information and position expressed on the map are expressed as digital data. Such a map expressed in a format that can be handled by an information processing device is called map data.

* Raster format and vector format The main purpose of a map is to express what entity exists on the ground surface and what shape it exists at which position. There are two types of representation methods: raster format and vector format.
Raster-format map data is a format in which a map is handled as image data, and a map that has been converted into a digital image or a digital photograph taken by aerial is an example of raster-format map data.
On the other hand, the map data in the vector format is a format that expresses the position, size, arrangement, etc. of an entity with dots and lines. For example, it is possible to express intersections with points and express roads connecting the intersections with lines. Since the position information is described in the points and lines, the existence positions of the entities represented by the respective information are stored as numerical values. The vector format data also has the feature of independently managing the data representing the shape and the data representing the attributes of the entity.
There is also a hybrid format with map data in both raster and vector formats. For example, in order to draw a road network on a map, roads are converted into data in a vector format, and the background image is stored as raster format data. It is conceivable to perform road drawing based on the format data.
In the first to sixth embodiments, at least map data having map data expressed in a vector format is targeted. In particular, information on roads is targeted for data holding information in a vector format. In this specification, it is assumed that map data at least information about roads is expressed in a vector format.

* Position expression method Here, the position expression method will be described. There are two types of position expression methods: an absolute position expression method and a relative position expression method.
The absolute position expression method is a method of indicating a position using a coordinate system indicating an absolute position on the earth such as latitude and longitude.
On the other hand, the relative position expression method is a method of indicating a position by how much the position to be expressed is deviated from a point expressed by a certain absolute position expression method as a reference point.
In the first to sixth embodiments, it is assumed that the entire map is expressed in a two-dimensional planar coordinate system, and the east direction is the positive direction of the X axis and the north direction is the Y axis in both the absolute position expression method and the relative position expression method. The number of meters away from each reference point with respect to the unit direction is expressed by two-dimensional coordinates on the XY plane. However, this coordinate system does not have to be used, and other coordinate systems may be used.

* Mesh division management The method for representing the position described so far is greatly related to the map data management method. For example, when handling map data all over Japan with a car navigation system or the like, if all the information included in the map data is collectively managed at the same level, the processing load becomes very large.
For example, when searching for position information existing within a circumference of a certain radius centered on a certain position, the search object is all position information. In the current car navigation system, there are cases where more than 10 million pieces of information are handled by facility information alone. In addition, in order to ensure the user's comfort during operation, there is a need to display the list in the form of a list that is sorted in the order of distance within 1 second from the start of the search. In a car navigation system, which is an embedded device that is inferior in processing capability compared to a computer or the like, there are many difficulties in achieving a request in a peripheral search that processes over 10 million data.
For this reason, in many map data, the entire area represented by the map data is divided into several areas, and all the information contained in each of the generated areas is handled as one set, and information division management is performed.
Targets that must be processed by extracting the divided area that overlaps the search area first, and making only the information contained in the extracted area as the search target even when performing a peripheral search by managing with the divided area Information can be narrowed down.
At that time, a reference point is provided for each area, and the position regarding the information included in the area is expressed by a relative position expression method using a representative point set for the area as a reference point. If the data size of the position data can be reduced, and the area is set sufficiently small, the curvature of the earth can be ignored when calculating the distance in the area, and the calculation should be performed in a plane orthogonal coordinate system. It is possible to reduce the amount of calculation. Hereinafter, unless otherwise indicated, the position is considered as a relative position expression, and in the case of comparing positions between different meshes, the comparison is made after converting to an absolute value expression.

As one simple area dividing method, a method of dividing the entire area expressed by the map data with a constant area without a gap and without overlapping can be considered.
FIG. 29 shows a specific example of this method.
In this figure, the entire area of Japan is divided into N * M areas by spreading N rectangular areas of a certain size in the X-axis direction and M areas in the Y-axis direction. Hereinafter, the divided area is referred to as a mesh. The lower left divided area is mesh (1, 1), the divided area adjacent to the X axis in the positive direction is mesh (2, 1), and the divided area adjacent to the Y axis in the positive direction is mesh (1, 2). ), The upper left segment is the mesh (1, M), the lower right segment is the mesh (N, 1), and the upper right segment is the mesh (N, M). Can express.
Since the size of the divided area is constant, if the representative point in all meshes is the lower left vertex of the mesh, for example, this method can be used if the absolute coordinates of the lower left vertex of the mesh (1, 1) are known. The representative point of the mesh can be obtained by calculation.

For example, when the side length in the X-axis direction of the mesh is Lx, the side length in the Y-axis direction is Ly, and the absolute coordinates of the lower left vertex (representative point) of the mesh (1, 1) are (X1, Y1), the mesh (A , B) the absolute coordinates (Xa, Yb) of the lower left vertex (representative point) are
_{X a = X 1 + (L} x * (A-1)) ... formula 1-1
_{Y b = Y 1 + (L} y * (B-1)) ... formula 1-2
It is possible to ask for.

Also, a method for determining which mesh an arbitrary position (X, Y) belongs to is as follows:
_{X a <X <= X a} + 1 ... Formula _{2-1 Y b <Y <= Y} b + 1 ... Equation 2-2
It is only necessary to find integers a and b (0 <a <= N, 0 <b <= M) satisfying the above. Can be identified.

  The division and management of map data in this way means that the in-vehicle device of the car navigation system has map data permanently, and the map data that obtains the necessary map from the map data management device via the network in a timely manner. There is a great advantage in the car navigation system in which the system is integrated in the server. Since map data is independent for each divided area, it is possible to preferentially transmit map data, such as the area around the vehicle position and the destination, to the in-vehicle device that is more needed by the in-vehicle device, It is easy to grasp which area data is exchanged when exchanging data between servers.

The method described so far has been a method in which the divided areas are not overlapped and spread without gaps.
However, in this method, there is a bias in the number of information depending on the city structure etc. where the divided areas are located, and it is necessary to manage the area even though there is no information in the divided areas located at sea. There is an efficiency aspect. In order to solve such a problem, by using R-Tree, which is one of the index methods for spatial information search, the divided area size is variable, and the overlapping of divided areas and a gap in the whole area are recognized. Divided area management may be performed. Alternatively, a multi-region division method may be used in which region division is performed in a multiplexed manner, and the region is divided into integer multiples as the hierarchy is increased.
However, in the present embodiment and Embodiments 1 to 6, description is made using a method of setting a divided region without a single layer of overlap that is easy to understand intuitively and that can be expressed in a simple manner and without gaps. .

Data Structure Used in Map Data Here, a specific example of the data structure used in map data is shown in FIG. 30 and will be described based on that.

* Point information and line information Most of the map data is point information for expressing what exists at that position, and line information that expresses a line connecting the two points with the position between the two points as the start point and the end point. Is expressed as a basic expression method.

FIG. 31 illustrates an example of point information and line information in map data.
For example, when the convenience store 101 exists at the position 102 of the latitude LAT102 and the longitude LON102, the convenience store 101 is expressed as a point 102 as point information, and the coordinates are expressed as (LAT102, LON102).
In addition, when a road 112 connects the point 103 of the position (LAT103, LON103) and the point 104 of the position (LAT104, LON104), the road 112 is expressed by line information, and the start point and the end point are the point 103, A point 104 is obtained.
Regarding the line information, the start point and the end point may be connected by a straight line, and there are K interpolation points (K> 0) between them, and the start point, the interpolation point 1, the interpolation point 2,. In some cases, it is expressed by a connecting line segment formed by tying.
At this time, all of the start point, end point, and interpolation point are collectively referred to as component points. The road 112 is actually composed of points 103 and 104 with the point 122 as the start point and the point 123 as the end point as interpolation points.
Therefore, the road 112 is converted into data with four constituent points.
In addition, as a specific example represented by a connecting line segment, there is a case where a road passing between two intersections has a shape that draws an arc, and an interpolation point at an appropriate position in order to approximate the shape. Is installed.
For example, the road 113 is a road connecting the start point 104 to the end point 124, but the shape is a curve, and has points 106 to 111 and 105 as interpolation points, and the points 104, 106, 107, 108, and 109 are included. , Point 110, point 111, point 105, and point 124, which are connected in order.

It is also possible to express a certain closed region by collecting a plurality of line information.
For example, when expressing the site shape of the convenience store 101, for example, a point 125, a point 126, a point 127, and a point 128 are set at the apex of the site, respectively, and the line information including the point 125 and the point 126, the point 126 is set. , Line information composed of points 127, line information composed of points 127 and 128, and line information composed of points 128 and 125.
The open area can be expressed by collecting a plurality of pieces of line information like the closed area. Here, the closed region and the open region are collectively referred to as a region, and information on the closed region or the open region is referred to as region information.
In Embodiments 1 to 6, since it is assumed that map data is expressed on a two-dimensional orthogonal coordinate plane, basic information can be expressed by point information, line information, and area information as an application thereof.
However, the map data is not limited to be expressed on the two-dimensional orthogonal coordinate plane, and may be expressed in, for example, a three-dimensional space. In that case, height information is added to the point information, and information generated by combining the height information may include not only line information and region information but also body information for expressing a three-dimensional region.

The point information in FIG. 30 illustrates a specific data structure of the point information.
The record size is an area for storing the data size of the entire point information. The point information has a role of describing information of what exists at the position, and the amount of information described varies depending on the item, so the point information basically has a variable size.
The type is an area for storing the classification number of what exists at that position. For example, values that can uniquely specify other stores, offices, houses, vacant spaces, etc. are stored from entities forming traffic paths such as roads, intersections, traffic lights, road signs, sidewalks, and median strips. The type only needs to be a value that can uniquely identify the classification of the entity represented by the point information, and may be expressed in a format such as a character string instead of a number.
The representative point is an area for storing coordinates indicating the position indicated by the point information. Since the point information is managed in mesh units, the representative points follow the relative position description using the mesh reference points. Since map data is represented by a two-dimensional orthogonal coordinate plane, representative points are also represented as two-dimensional vectors.
The number of attributes is an area for storing the number of attribute information describing the entity represented by the point information.
The attribute list is an area for storing attribute information related to the entity represented by this point information, and stores the same number of attributes as the value held by the number of attributes. For example, when certain point information represents an intersection, information such as the name of the intersection is stored. An example of a specific attribute data structure will be described later.
The extended data is a spare area used when data is additionally described in addition to the data described above.

The line information in FIG. 30 illustrates a specific data structure of the line information.
The record size is an area for storing the data size of the entire line information. The line information has a role of expressing the shape of a certain entity, and the amount of information described varies depending on the shape and the number of constituent points, so the line information basically has a variable size.
The type is an area for storing an information classification number indicating whether the line information represents a line or an area. In the present embodiment, the information classification number that can be classified as line information or area information may be used. However, if it is desired to classify other shapes in particular, an information classification number corresponding thereto may be added. For example, when it is desired to express the map data in three dimensions, it is necessary to express the body information as line information, so an information classification number corresponding to the body information is added. The type only needs to be a value that can uniquely identify the information expressed by the line information, and may be expressed in a format such as a character string instead of a number.
The number of constituent points is an area for storing the number of constituent points included in the line information.
The component point list is an area for storing coordinates indicating the position of the component point included in the line information, and stores the same number of coordinates as the value stored in the number of component points. In the present embodiment, the coordinates are set like the constituent point where the first coordinate of the constituent point list is the starting point, the next coordinate is connected to the starting point, and the next coordinate is connected to the previous constituent point. Assume that the last element stores the coordinates of the end point.
The number of attributes is an area for storing the number of attribute information describing the entity represented by the line information.
The link / node shape attribute list is an area for storing attribute information that represents the shape of a link that is a line segment created by connecting nodes or constituent points in this line information. The same number of attributes as the value to be stored are stored. For example, information necessary for drawing information such as line thickness, color, drawing shape at a joint point when drawing a certain link is stored as an attribute.
The extended data is a spare area used when data is additionally described in addition to the data described above.

The attributes shown in FIG. 30 are data structures representing attribute information stored in the attribute list of point information and the link / node shape attribute list of line information.
The attribute type is an area for storing an attribute classification number indicating what attribute this attribute represents. For example, when the point information represents an intersection, the attribute classification number indicating the name is stored as the attribute type of the attribute storing the intersection name. Further, when a link included in the line information is drawn, an attribute classification number indicating the width is stored as the attribute type of the attribute expressing the line width. The attribute type only needs to store information that can uniquely identify what attribute the attribute represents, and is not limited to a number and may be in other formats such as a character string.
An attribute dependency flag is the width of a straight line for an attribute that defines the shape when drawing a link included in line information as a straight line, for example, when that attribute has the purpose of modifying another attribute. In the case of defining the color or the color, the attribute defining the width or the color is subordinate to the attribute defining the straight line. In that case, the attribute subordinate flag stores the order of the elements of the link node shape attribute list as subordinate attributes. In the case of an attribute that is not subordinate, 0 is stored in the attribute subordinate flag.
The attribute size is an area in which a value indicating the data size of the attribute value is stored.
The attribute value is an area for storing the value of the attribute, and the size thereof is the same as the value stored in the attribute size. The data structure inside the attribute value is defined for each attribute type. For example, when the attribute type is a name, the attribute value data structure is a character string, but the specific link included in the line information In the case of an attribute representing a drawing shape, the data structure of the attribute value may include the order in the constituent point list of the constituent point that is the starting point of the link that defines the drawing shape, and information indicating the shape.

The mesh data shown in FIG. 30 has a data structure for storing information representing entities included in a certain mesh.
The record size is an area for storing a value indicating the mesh size.
The mesh identifier is an area for storing a value that can uniquely identify which mesh in the entire map is the mesh. If the map as shown in FIG. 29 is spread with the same shape mesh without gaps and overlaps, for example, the coordinates indicating the number of meshes on the right and the number of meshes on the top, counting from the lower left mesh It may be information. The mesh identifier may be in any data format as long as the mesh can be uniquely identified, and may be a coordinate, a character string, or a numerical value.
The number of points is an area for storing the number of point information items stored in the mesh data.
The number of lines is an area for storing the number of line information items stored in the mesh data.
The point information list is an area for storing point information to be stored in this mesh, and the number of the point information is the same as the value of the number of points.
The line information list is an area for storing line information stored in the mesh, and the number of the line information is the same as the value of the number of lines.

The basic management information in FIG. 30 is a data structure for holding information necessary for drawing a map on a display device using the data described so far.
The base mesh representative point is an area for storing the coordinates of the reference point of the mesh data used as a reference. The mesh data does not store the coordinates of the reference point for each mesh. However, as described above, if the reference point of the reference mesh data is known, the reference point of other mesh data can be derived by arithmetic. This is because the description is unnecessary.
The base mesh identifier is an area for storing a mesh identifier of mesh data serving as a reference.
The display target mesh count is an area for storing the number of meshes that overlap with the drawing area.
The display target mesh is a region for managing a list of mesh data of meshes that overlap with the region to be drawn, and the number of elements coincides with the value stored in the number of drawing target meshes.
When drawing a map, drawing with actual measurement values described in map data is not realistic, and drawing is usually performed with a reduced size based on a certain scale. This is an area for storing the scale at that time. For example, if the scale is 1/25000, there may be a case where 25000 is stored in the scale area. Further, when the scale options are limited, an enumerator may be defined as in Scale of FIG. 30 and the scale may be expressed by the value.
The display area center of gravity is an area for storing the coordinates of the center of gravity of the area displayed on the display device on the map. In this embodiment, it is assumed that the display area is a rectangle, but it is not necessary to limit to a rectangle, and other shapes may be used.
The display area width is an area in which the length of the horizontal side of the display area is stored as an actual measurement value.
The display area height is an area in which the length of the vertical side of the display area is stored as an actual measurement value. For example, when displaying a map with a scale of 1/25000 on a 10 cm long and 20 cm wide area on the display device,
Display area width = 20 * 25000 cm = 5000 m Display area height = 10 * 25000 cm = 2500 m, and it is considered that 5000 is stored in the display area width area and 2500 is stored in the display area height area. It is done.
The display area rotation angle is an angle formed by the side of the length of the display area width and the X axis, and the angle is not less than 0 degrees and less than 360 degrees. The rectangle in the figure specifically described with reference to FIG. 32 is a display area, the display area width is Xr, and the display area height is Yr. At this time, the side corresponding to the display area width is the long side of the rectangle, and the angle formed by the long side and the X axis is θ.

  The data structure described above is a specific example configured on the assumption that information assumed to be used in the map drawing device 1201 and the map data management device 1301 of Embodiments 1 to 6 is stored without leaking. It is not always necessary to hold the same information as the data structure described here. In addition, information that does not exist in the data structure described here should not be held.

A specific example of mesh data based on the data structure shown in FIG. 30 is shown in FIG.
FIG. 33 shows examples of record size, mesh identifier, number of points, number of lines, point information list, and line information list according to the format of mesh data of FIG.
In the example of FIG. 33, since the number of points is 10, point information lists (record size, type, representative point, number of attributes, attribute list, list including extended data items) for 10 lines should be arranged in the mesh data. However, for convenience of drawing, only one point information list is illustrated in FIG.
Similarly, since the number of lines is 3, the mesh data includes items of a line information list (record size, type, number of constituent points, constituent point list, number of attributes, link node shape attribute list) for three lines. List) should be arranged, but for convenience of drawing, only one line information list is illustrated in FIG.
In the line information list shown in FIG. 33, since the number of attributes is 10, 10 link node shape attribute lists should be arranged. However, for convenience of drawing, in FIG. Only the node shape attribute list is illustrated.

In the point information list, the first point information (shown in FIG. 33) indicates that there is an intersection at the relative position coordinates (PX1, PY1) from the type and representative point. It can also be seen from the attribute list that the shape is T-junction, the name is in front of ABC elementary school, and the color of the intersection is Gray.
In addition, for the second and subsequent point information (not shown in FIG. 33), the type of road (national road, prefectural road, etc.), road number, road lane number, lane from the type, representative point, relative position coordinates, and attribute list. The width, the position of the intersection, the shape of the intersection, the color of the intersection, the position of the traffic light, the traffic light shape, etc. can be extracted.

Also, in the line information list, the first line information (up to the middle is shown in FIG. 33) expresses a line having the type, the number of constituent points, and the starting point (PX81, PY81) and the end point (PX82, PY82) from the constituent point list. ing. From the link node shape attribute list, the shape is straight, the road color is Gray, the entire road width is 3, the forward and reverse lanes are one, the median strip width is 1, and the median strip color Is drawn with Green, and the boundary line is drawn with Dark gray (some elements are not shown).
Also for the second and subsequent line information (not shown in FIG. 33), the road shape, road color, road width, median strip width from the type, the number of constituent points, the constituent point list, and the link / node shape attribute list In addition, the color of the median strip, the color of the boundary line, and the like can be extracted.

FIG. 34 is a diagram illustrating a specific positional relationship in the mesh data of FIG.
In FIG. 34, it is assumed that the intersection is shown according to the description of the mesh data of FIG.
The elements of the point information list correspond to, for example, positions 401, 402, 403, 404, 405, 406, 407, 408, 409, 410 in order.
Moreover, the element of line information respond | corresponds to the vectors 411, 414, and 417 in order, for example. Also, for example, the first line information start point and end point correspond to points 412, 413, the second line information start point, end point corresponds to points 415, 416, and the third line information start point, end point corresponds to points 418, 419. To do.

However, mesh data contains only position and shape information, and it is impossible to derive a relationship between an intersection, an intersection entrance, and a road.
Such a data representation method that does not explicitly describe phase information is called an implicit phase description method. Compared to the method that explicitly describes the phase information in the data, the data size is small, and there is an advantage that data can be easily added to or deleted from the map data. It can be said that it is a data expression method.
In the map data expressed by the implicit phase description method, the relationship between information is usually derived by the positional relationship. For example, a method for deriving a relationship is introduced by introducing a rule that information that exists within a circumference of radius R meters of information representing a certain entity is related. This rule is usually determined together with the data structure, but the data processor may introduce a rule different from the rule to derive the relationship.

  In the present embodiment, a circle is used to derive the relationship, but it is not necessary to be a circle. Other shapes may be used, and the parameters for determining the shape may be the same for any entity. It may be fixed for each type, given as an attribute for the entity, or determined by other methods. Further, the determination may be made based on whether or not the coordinates of the points coincide with each other instead of the shape.

  Further, in this embodiment, only the relationship between the intersection and the intersection entrance, the traffic light, the relationship between the intersection entrance and the road, and the relationship between the line information and the road attribute are illustrated, but there is no other relationship, Other entities, such as the relationship between roads and roads, the relationship between roads and signs, the relationship between roads and intersections, buildings and facilities, etc. .

In FIG. 34, all points that fall within a circle 420 centered on the intersection position 401 are related to this intersection. Therefore, since the positional relationship between the intersection entrance and the traffic light connected to this intersection is determined, it is possible to determine in what direction the T-junction should be drawn. In this case, since the intersection entrance is related to the intersection from the left side and the top and bottom, it can be understood that the T-junction should be drawn in a shape obtained by rotating T 90 degrees counterclockwise.
Also, the points 408, 409, and 410 indicating the road attributes are related to the points included in the circles 424, 425, and 426, and it is determined which line information is the road attribute and corresponds to the vector 411. The line information corresponding to the national road No. 25, the line information corresponding to the vector 414 as the national road No. 31, and the line information corresponding to the vector 417 as the national road No. 56 are determined.
Similarly, the intersection entry points 402, 404, and 406 are assumed to be related to the respective intersection entry points that enter the circles 421, 422, and 523, and which intersection entry point is connected to which road. Is determined. For example, from the mesh data illustrated in FIG. 33, for example, National Route 25 is connected to the entrance to the intersection from the right side, National Route 31 is connected to the entrance to the intersection from below, and National Route 56 is connected to the entrance to the intersection from above. It is guided to do.

In this embodiment, roads of the same type and number are represented by one line information.
For example, in the data of FIG. 34, the national highway No. 25 is only a line segment represented by the vector 411.
If the national highway 25 still continues on the right side of the vector 411, it is necessary to set the composing point until the national highway 25 ends. The reference point is normally set as a change point of the road so that it does not greatly differ from the actual road shape when drawing the road. However, the expression with one line information is for the sake of simplicity of the embodiment, and it is not necessary to express roads of the same type and number with one line information, but with a plurality of line information and point information. You can express it.

Next, a method for expressing a road passing through a plurality of meshes will be described.
Since roads exist regardless of the mesh division method, many roads exist across a plurality of meshes. Since it is necessary to manage the information independently in units of meshes, such roads separate line information at mesh breaks, and point information indicating road attributes is set for each line information. .
A specific example will be described.
FIG. 35 illustrates a road 1005 passing through meshes 1001, 1002, 1003, and 1004. When this road 1005 is National Road B, the data of National Road B in each mesh is as shown in FIG.

FIG. 36 illustrates how the national road B shown in FIG. 35 is represented by data in each mesh.
Route B continues from mesh 1004 through mesh 1003 to mesh 1001. Therefore, the national road B is divided and managed into the national road B existing in the mesh 1004, the national road B existing in the mesh 1003, and the national road B existing in the mesh 1001. Therefore, the mesh data corresponding to the mesh 1004 stores line information 1101 and point information 1104 that holds the attribute of the national road B. Similarly, the mesh data corresponding to the mesh 1003 has point information 1105 that holds the attributes of the line information 1102 and the national road B, and the mesh data corresponding to the mesh 1101 holds the attributes of the line information 1103 and the national road B. Point information 1106 is stored.

When such data division is performed, it is said that there is a national road B that exists discontinuously for each mesh when processing is performed on the assumption that the portions divided by the boundary line of the mesh are not connected as they are when drawing. Wrong interpretation.
Therefore, when there is line information that represents a road that ends near the mesh boundary line, the mesh boundary line is centered on the component point closest to the mesh boundary line among the component points of the line information. If there is a road of the same type and the same number within a certain range including the adjacent mesh adjacent to the road, the drawing process is performed assuming that the road is connected.
For example, the line information 1101 sets a fixed range 1107 with reference to the constituent point 1109 closest to the boundary line with the mesh 1103, and searches the mesh 1103 for the line information of National Route B that includes the constituent point in the range. , Line information 1102 corresponds. Therefore, in the process, the process is performed assuming that there is a road between the configuration point 1109 and the configuration point 1110. Similarly, a fixed range 1108 is set on the basis of the constituent point 1112 closest to the boundary line with the mesh 1101 of the line information 1102, and a search is performed from the mesh 1101 to determine whether there is line information of National Route B including the constituent point in the range. Since the line information 1103 is applicable, the processing is performed assuming that there is a road between the configuration point 1112 and the configuration point 1111.

Next, FIG. 37 shows an example in which a map is specifically drawn on the mesh data of FIG.
In this example, the entire mesh (M, N) is drawn as a drawing area. At this time, the position and distance of each entity are calculated from the representative points of the point information and the constituent points of the line information. Since each coordinate is described in a relative coordinate expression from the lower left of the mesh, the positional relationship is directly derived from the coordinate. Also, since the distance between two points is premised on a two-dimensional orthogonal coordinate plane, for example, when obtaining the distance D between two points (X1, Y1) and (X2, Y2),
D ^ 2 = (X1-X2) ^ 2 + (Y1-Y2) ^ 2
Can be calculated using.
However, since the positional relationship and distance can be obtained by actual measurement values, it must be converted to the size on the screen using the scale information of the basic management information, but the positional relationship and distance were obtained by dividing by the scale value. The result can be calculated as the size on the screen.
An intersection 301 is an intersection corresponding to the first element of the point information list. Intersection entrances 302, 304, and 306 are connected to the intersection, and correspond to the second, fourth, and sixth elements of the point information list, respectively. Next, vehicle traffic lights 303, 305, and 307 are installed at intersection entrances, and correspond to the third, fifth, and seventh elements of the point information list, respectively.
Finally, roads 308, 309, and 310 are connected to the intersection entrance, and the point information indicating the roads corresponds to the eighth, ninth, and tenth elements of the point information list, and the shapes thereof are line information. Corresponds to the first, second, and third elements of the list. Connections between entities are only performed between entities with derived relationships.

  In FIG. 37, the mesh area is the drawing area. However, in general, a plurality of meshes are used, and some meshes use all corresponding mesh data. Other meshes use only the information excluding the portion that protrudes from the drawing area. The map will be drawn.

Based on the above description, a procedure for the map drawing device 1201 to acquire map data from the map data management device 1301 will be described based on the sequence diagram of FIG.
The sequence of FIG. 38 shows an example of the map data request step (S1001) and the map data reception step (S1002) of FIG. 2 shown in the first embodiment.

First, the communication device 1205 of the map drawing device 1201 makes a map data request to the map data management device 1301.
Along with this map data request, it is possible to instruct a specific area to be acquired. Examples of the instruction method include the following (1) to (6).
(1) An area is indicated by a mesh identifier list corresponding to the area.
(2) The point to be acquired is indicated by the point information, and the area including the point is determined on the map data management device 1301 side.
(3) A point to be acquired is instructed by point information, and a radius centered on the point is also instructed to indicate an area to be acquired.
(4) A necessary route is instructed by line information, and an area including the route is determined on the map data management device 1301 side.
(5) Build surface information and indicate the area to be acquired with the surface information.
(6) The current position, waypoint, and final destination are described in the request, and a route passing the current position, waypoint, and final destination is created on the map data management device 1301 side, and an area including the route is determined.

Further, when the area to be specifically acquired is not designated, the map data management device 1301 may determine that all map data is acquired.
The map data management device 1301 determines the mesh to be provided to the requesting in-vehicle device according to the received map data request, the presence / absence of the parameter given thereto, and the content of the parameter. Then, the mesh identifiers of the meshes determined to be provided to the in-vehicle device are returned to the in-vehicle device in a list format. At this time, information indicating in which order the mesh should be acquired may be added to the mesh identifier list. It is also possible to make an arrangement in the system, such as obtaining the list in the storage order.
The in-vehicle device that has received the mesh identifier list sequentially requests the map data management device 1301 for a mesh file in which information about the mesh is stored using the identifier stored in the list as a parameter.
At this time, when the acquisition order is described in the mesh identifier list, or when the system has an agreement regarding the acquisition order, the acquisition order may be obtained according to the determined order. The order of mesh file acquisition may be determined on the in-vehicle device side using the contents of the identifier stored in the mesh identifier list, information stored in the in-vehicle device, various information acquired from the vehicle, and the like. Absent. Further, after the request is completed, the vehicle device secures a mesh data area for storing mesh information in the memory area.

Next, the map data management device 1301 that has received the mesh file request returns a mesh file corresponding to the mesh identifier stored in the request to the in-vehicle device.
In the mesh file, a point information file list that summarizes information about the point information file that stores the point information existing in the mesh, and line information that summarizes information about the line information file that stores the line information existing in the mesh A file list is stored.
Similar to the mesh identifier list, each point information file list, each line information file list, or information that indicates the order in which they should be acquired in an integrated manner may be added. You can also make an arrangement with

  Next, the in-vehicle device that has received the mesh file acquires the file information stored in the point information file list and line information file list stored in the file, and each point information file and line information based on the information. Make a file acquisition request. At that time, as in the case of the mesh identifier list, if the acquisition order is described in the mesh file in advance or if there is an arrangement as a system for the acquisition order, it may be acquired according to the determined order. Similarly, using the information stored in the mesh file, the information stored in the in-vehicle device, various information acquired from the vehicle, etc., the acquisition order of the point information file and the line information file is determined on the in-vehicle device side. It doesn't matter.

  Next, the map data management device that has received the point information file acquisition request or the line information file acquisition request returns the corresponding point information file or line information file to the in-vehicle device based on the request. Here, the point information file is a file in which one or more point information is recorded, and the line information file is a file in which one or more line information is recorded.

  Finally, the in-vehicle device that acquired the point information file or line information file analyzes the file, secures the memory area necessary to store all or part of the information stored in the file, and Store data in the area. Then, the information is associated with the corresponding mesh data.

As described above, when the in-vehicle device acquires the map data via the network, depending on the status of the network to be used, it may be possible that not all the requested map data can be acquired and a part of the map data cannot be acquired.
For example, if a network failure occurs during map data acquisition and communication between the in-vehicle device and the map data management device is not possible, or if a mobile phone network is used for the network, the mobile phone used by the in-vehicle device If the device falls short of power and becomes unable to communicate, or it becomes impossible to accept a request from the in-vehicle device due to a failure in the communication processing system of the map data management device, or the in-vehicle device in which the map data management device exceeds the allowable number For example, there is a case where a response from the map data management device cannot be returned to the in-vehicle device because the request from the server is received, or a case where the server function is down due to a malfunction of the processing system of the map data management device.

In the first to sixth embodiments described above, processing is performed using position information called a current position, but the map drawing apparatus 1201 that actually acquired the current position using the position detection device 1203 is actually used. Although the existing position information may be the current position, for example, the position determined by the central controller 1202 may be the current position.
Further, a position input from the outside of the system such as a user using the operation panel 1207 may be set as the current position.

In the first to sixth embodiments, processing is performed using the moving direction information called the current traveling direction. The current traveling direction is normally the current position before the current position and the current position before that. A vector starting from the coordinates may be used, but for example, a vector determined by the central controller 1202 may be the current traveling direction.
Further, a vector input from the outside of the system such as a user using the operation panel 1207 may be set as the current traveling direction.

As described above, as a specific example of determining the current position and the current traveling direction based on the position information acquired from the position detection device 1203, a map of the current surrounding area while the user holding the map drawing device 1201 is moving An application that can display is considered.
As a specific example in which the map drawing device 1201 determines the current position and the current traveling direction, an application for demonstrating the operation of the map drawing device can be considered.
As a specific example in which the input from the user or the like outside the system is the current position and the current traveling direction, an application that allows the user to display a map of an area different from the current position is conceivable.

* Overall Processing Step Next, the overall processing step in the map drawing device 1201 will be described.
FIG. 39 is a flowchart showing an overall processing flow in the map drawing device 1201.

When the map drawing apparatus 1201 is turned on, a startup process S101 is executed.
Here, initialization of the map drawing device 1201, pre-processing of the next processing S102, and the like are performed.
When the activation process S101 is completed, a map drawing process S102 is executed.
When the trigger for ending the map drawing process is triggered, such as when the power-off button is pressed while the map drawing process S102 is being executed, the drawing process end request is notified, or the end time is reached, the next end process S103 is performed. The entire process of the map drawing device 1201 is completed.
Further, in the end process S103, the state of the immediately preceding process S102 may be stored so that the process S102 can be started in the form of returning to the previous end state at the next activation.

Next, the overall processing steps related to the map drawing process S102 shown in FIG. 39 will be described.
FIG. 40 is a flowchart of the entire process related to the map drawing process S102.
In this process, a process of performing an initial map output to the map output device 1206 immediately after activation and a process of updating the map output in accordance with a change in the current position are performed.

When the map drawing process S102 is started, a basic information processing acquisition S201 is first executed.
In this process, information on the base mesh representative point, base mesh identifier, and scale in the basic management information is acquired and the basic management information is updated.
A method of acquiring the base mesh representative point and the base mesh identifier by connecting to the map data management device 1301 from the communication device 1205 can be considered.
In addition, when it is stored in the map storage device 1204, it may be acquired from the map storage device 1204.
Regarding the scale, a method in which the central controller 1202 unconditionally sets a default value or a method in which an input from a user through the operation panel 1207 is used can be considered. In addition, when the scale information is stored in the map storage device 1204, the information may be acquired.

Next, the current position acquisition process S202 is executed.
In the first to sixth embodiments, processing is performed using position information called a current position.
The current position acquisition process S202 is a process for determining the current position. As described above, the current position information obtained by using the position detection device 1203 and where the map drawing device 1201 actually exists is usually used as the current position. However, for example, the position determined by the central controller 1202 may be the current position. Further, a position input from the outside of the system such as a user using the operation panel 1207 may be set as the current position.

Next, a drawing area determination process S203 is executed.
In this process, the display area centroid, display area width, display area height, and display area rotation angle of the basic management information are determined.
Note that the center of gravity of the display area is the same value as the current position determined in step S202.
The display area width and the display area height are the width and height of the map size to be output from the map output device 1206.
There are various determination methods for the map size. For example, when a map having a scale of S on a full screen is desired to be displayed on a display having a display area of vertical Dh centimeters and horizontal Dw centimeters, the map size can be obtained by the following formula.
Display area width = Dh * S / 100 meters Display area height = Dw * S / 100 meters

For example, when Dh = 15, Dw = 20, and S = 25000,
Display area width = 15 * 25000/100 = 3750 meters Display area height = 20 * 25000/100 = 5000 meters.

Next, as a method for determining the display area rotation angle, when the previous calculation result is stored in the map storage device 1204, the value may be used.
In addition, the default value may be set by the central controller 1202 or may be set to a value input by the user on the operation panel 1207.

Next, a drawing target mesh calculation process S204 is executed.
In this process, the identification information of the mesh that overlaps the drawing area obtained in process S203 is calculated.
A specific algorithm will be described with reference to FIG.

  In FIG. 41, a rectangle 1301 is a display area, and each of the squares surrounding it is a mesh. The lower left mesh is identified as mesh (1, 1), the upper adjacent mesh is identified as mesh (1, 2), and the right adjacent mesh is identified as mesh (2, 1). A point 1305 is the center of gravity of the display area, and is the coordinate determined in step S203. Points 1302, 1303, 1304, and 1305 are the vertices of the display area.

The coordinates (X1, Y1), (X2, Y2), (X3, Y3), (X4, Y4) of the vertices 1302, 1303, 1304, 1305 are the display area width Aw when the display area rotation angle is 0 degree, Using the display area height Ah and the display area center of gravity (Xc, Yc),
X1 = X2 = Xc + Aw / 2 (≡Xupper)
X3 = X4 = Xc-Aw / 2 (≡Xlower)
Y1 = Y4 = Yc-Ah / 2 (≡Yupper)
Y2 = Y3 = Yc + Ah / 2 (≡Ylower)
As required.
Therefore, when the display area rotation angle is θ, using a two-dimensional rotation matrix,
X1 = Xupper * cos θ−Yupper * sin θ
Y1 = Xupper * sinθ + Yupper * cosθ
X2 = Xupper * cos θ−Ylower * sin θ
Y2 = Xupper * sinθ + Ylower * cosθ
X3 = Xlower * cos θ−Ylower * sin θ
Y3 = Xlower * sin θ + Ylower * cos θ
X4 = Xlower * cos θ−Yupper * sin θ
Y4 = Xlower * sinθ + Yupper * cosθ
Can be obtained as

Here, in order to simplify the description, when θ is 90 degrees or more, the name of the display area vertex is replaced with the vertex adjacent in the clockwise direction.
That is, the vertex 1302 is rewritten as the vertex 1305, the vertex 1303 is rewritten as the vertex 1302, the vertex 1304 is rewritten as the vertex 1303, and the vertex 1305 is rewritten as the vertex 1304. By this operation, the vertex 1302 is set as the vertex having the largest X coordinate value.

When θ is 0 degree or 90 degrees, each side of the display area is parallel to the axis. Therefore, a method for obtaining a mesh that overlaps the display area is as follows.
First, the mesh identifier of the mesh to which each vertex of the display area belongs is obtained. Which mesh a certain point belongs to can be determined using equations 1-1, 1-2, 2-1, 2-2. Since each side is parallel to the axis, the mesh identifiers of the mesh to which the vertices 1302, 1303, 1304, 1305 belong are (MX1, MY1), (MX2, MY2), (MX3, MY3), (MX4, MY4). if you did this,
MX1 = MX2 ≧ MX3 = MX4
MY2 = MY3 ≧ MY1 = MY4
Is established.
Therefore, a set D of mesh identifiers of meshes that overlap the display area is
D = {(x, y) | MX1 ≦ x ≦ MX4 and MY2 ≦ y ≦ MY4}
Can be obtained as

Next, a method for obtaining a set D of mesh identifiers of meshes that overlap the display area when θ is other than 0 degrees and 90 degrees will be described.
Here, that θ is not 0 degree and 90 degrees means that each side of the display area is not parallel to the axis. Therefore, the following method is used.
From the vertex 1302 that is present on the rightmost side in the display area, a linear expression that advances to the vertex 1303 and a linear expression that advances to the vertex 1305 are obtained. Since the linear expression can be uniquely determined if the slope and intercept of the parameter are determined, they are obtained.
Since the inclination is obtained by the difference between the vertices, the respective inclinations Grad23 and Grad25 are
Grad23 = (Y1-Y2) / (X1-X2)
Grad25 = (Y1-Y4) / (X1-X4)
As required.
Next, each section Inter23 and Inter25 is
Inter23 = Y1-Grad23 * X1 = Y2-Grad23 * X2
Inter25 = Y1-Grad25 * X1 = Y4-Grad25 * X4
Is required.

By using the same method, it is possible to obtain a linear expression of a line segment going from the vertex 1303 to the vertex 1304 and from the vertex 1305 to the vertex 1304, and assuming that their slope and intercept are Grad34, Grad54, Inter34, and Inter54.
Grad34 = (Y2-Y3) / (X2-X3)
Grad54 = (Y4-Y3) / (X4-X3)
Inter34 = Y2-Grad34 * X2 = Y3-Grad34 * X3
Inter54 = Y4-Grad54 * X4 = Y3-Grad54 * X3
It is possible to ask for.

Next, the coordinates at which the boundary line of the display area intersects with the boundary line parallel to the Y axis of the mesh are obtained.
First, the X coordinate of the boundary line of the mesh is obtained. Only the mesh boundary line where the diagonal line connecting the vertex 1302 and the vertex 1304 of the mesh that may possibly intersect with the boundary line of the display area intersects.
Since the mesh identifier of the mesh having the vertex 1302 is (MX1, MY1) and the mesh identifier of the mesh having the vertex 1304 is (MX3, MY3), the X component Xc of the mesh identifier of the mesh that may intersect Is
The range is MX3 ≦ Xc ≦ MX1.
The X component of the boundary line parallel to the Y axis of the mesh in this range can be obtained by Expression 1-1.

Next, since the X component of the boundary line parallel to the Y axis of the mesh can be obtained, the intersection coordinates of the boundary line from the vertex 1302 to the vertex 1303 are first obtained using the value, and then the vertex 1303 is obtained. To obtain the intersection coordinates of the boundary line following the vertex 1304, arrange them in descending order of the X component,
Cupper = {(CX1, UY1), (CX2, UY2),. . . , (CXk, UYk)
However, CX1>CX2>. . . > CXk}
And
Similarly, the intersection coordinates of the boundary line from the vertex 1302 to the vertex 1305 and the intersection coordinates of the boundary line from the vertex 1305 to the vertex 1304 are obtained.
Crower = {(CX1, LY1), (CX2, LY2),. . . , (CXk, LYk)
However, CX1>CX2>. . . > CXk}
And

Next, the mesh identifier of the mesh that touches from the left side of the line segment between the same rank coordinates of Copper and Crower is obtained, and the set thereof is set as D.
Finally, if the identification number of the mesh to which the vertex 1303, vertex 1304, and vertex 1305 belong is not included in D, adding that mesh identifier to D results in a set of mesh identifiers for meshes that overlap the display area.

By using the above method, it is possible to obtain a mesh identifier set of meshes that overlap the display area.
The method described here is merely an example of a method for obtaining, and other methods may be used.
In addition, when a mesh is generated by a configuration method different from the mesh configuration method assumed in the present specification, there is a method suitable for this, and in that case, the method may be used.

When the process S204 is completed, a mesh data acquisition process 205 is executed next. In this process, mesh data corresponding to the mesh identifier set D obtained in step S204 is acquired from the map data management apparatus 1301.
The processing executed here may be the method described in FIG.
However, this method can only acquire mesh data that overlaps the display area.
However, for example, when performing route guidance from the movement start point 1401 to the destination 1402 as shown in FIG. 42, the area 1404 (gray mesh area) to be displayed is already known from the guidance route 1403. It has become. In that case, it is also possible to perform a process of simultaneously obtaining mesh data that is known to be the target of future display in route guidance.
Moreover, when acquiring mesh data other than the mesh data to be displayed for other reasons, a priority may be given to each mesh data, and processing for acquiring mesh data in descending order of priority may be performed. .
For example, when performing route guidance, there may be a request to refer to information around the destination in advance.
In addition, it is easy to predict traveling according to route guidance, so when you want to display a guidance route, you want the mesh data that overlaps with the region that must be displayed at the same time, but the area around that region moves away from the guidance route. In such a case, it is necessary only in exceptional circumstances, and such information may be acquired after an area that must be displayed at the same time when displaying a guide route.
In such a case, the mesh data that overlaps the current display area has the highest priority, and the mesh data that overlaps the area that needs to be displayed at the same time when displaying the guide route is the second priority. The mesh data acquisition process may be executed by setting the mesh data group 1405 around the destination as the third priority and the mesh data group 1406 around the guide route as the third priority.
The mesh data that overlaps the route close to the movement start point 1401 is also required earlier than the mesh data that overlaps the route close to the destination 1402, so the guide route mesh data 1404 is also in the order of passage of the guide route 1403. The acquisition priority may be set.

Next, the mesh data drawing process S206 is executed, but if it is normal, the process S205 is started after the process S205 is completed, so that there is no omission in the necessary map display in the output result. I can do it.
However, the processing S206 may be operated in parallel when data that can be displayed is acquired in the acquisition processing performed in the processing S205. At that time, when the map is displayed as an image, as shown in FIG. 28, different display may be performed in the area where the map can be displayed and the area where the map cannot be displayed. In such a case, the map output having a lot of omissions in the first output result is a map that gradually loses omission by operating the processing S206 in parallel every time there is a data response to the processing S205. Since output can be performed, such a method may be used.

Finally, the map update drawing process S207 is a process that is normally executed when the current position is changed as a trigger.
If the current position is changed, the center of gravity of the display area is changed, so that the mesh to be drawn may also change. Therefore, when the processes S203 and S204 are executed again and a mesh identifier set D ′ different from the previous mesh identifier set D is generated, meshes included in D ′ but not included in D are included. In order to acquire the mesh data corresponding to the identifier, S205 is executed, and the map is re-output in step S206.
Conversely, if there is mesh data that is included in the set D and not included in the set D ′, the information is stored in the map storage device 1204. The mesh data stored in the map storage device 1204 normally remains stored until the map drawing device 1201 is powered off.
There is also a method in which the map data management device 1301 stores the map data until the date and time when the map data is scheduled to be updated while the storage period is stored even after the power is turned off.
By adopting this method, it is guaranteed that the acquired mesh data is the latest until the map data is updated, so that it can be used during that time. In addition, the map data management device 1301 confirms whether the mesh data stored in the map storage device 1204 has been updated on the map data update scheduled date. If not, the map data is stored until the next map data update scheduled date. It may be left as it is. By adopting this method, once saved mesh data is saved in the map storage device 1204 until it is updated, and it is not necessary to communicate with the map data management device 1301 when using the mesh data. Therefore, the communication load can be reduced.

  The process S207 is repeatedly executed with the current position change as a trigger until there is a trigger to end the map drawing process.

Finally, a hardware configuration example of the map drawing device 1201 shown in the first to seventh embodiments will be described.
FIG. 43 is a diagram illustrating an example of hardware resources of the map drawing device 1201 described in the first to seventh embodiments.
The configuration in FIG. 43 is merely an example of the hardware configuration of the map drawing device 1201, and the hardware configuration of the map drawing device 1201 is not limited to the configuration described in FIG. Also good.

43, the map drawing device 1201 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, a processing unit, a microprocessor, a microcomputer, and a processor) that executes a program.
The CPU 911 is connected to, for example, a ROM (Read Only Memory) 913, a RAM (Random Access Memory) 914, a communication board 915, a display device 901, a keyboard 902, a mouse 903, a speaker 908, and a magnetic disk device 920 via a bus 912. And control these hardware devices.
Further, the CPU 911 may be connected to an FDD 904 (Flexible Disk Drive), a compact disk device 905 (CDD), a printer device 906, and a scanner device 907. Further, instead of the magnetic disk device 920, a storage device such as an optical disk device or a memory card (registered trademark) read / write device may be used.
The RAM 914 is an example of a volatile memory. The storage media of the ROM 913, the FDD 904, the CDD 905, and the magnetic disk device 920 are an example of a nonvolatile memory. These are examples of the storage device.
A communication board 915, a keyboard 902, a mouse 903, a scanner device 907, an FDD 904, and the like are examples of input devices.
A communication board 915, a display device 901, a speaker 908, a printer device 906, and the like are examples of output devices.

The display device 901 displays a drawn map and notification information.
In addition, the speaker 908 outputs voice notification information.

As shown in FIG. 1, the communication board 915 is connected to the map data management apparatus 1301 and a network.
The communication board 915 receives map data from the map data management device 1301.

The magnetic disk device 920 stores an operating system 921 (OS), a window system 922, a program group 923, and a file group 924.
The programs in the program group 923 are executed by the CPU 911 using the operating system 921 and the window system 922.

The RAM 914 temporarily stores at least part of the operating system 921 program and application programs to be executed by the CPU 911.
The RAM 914 stores various data necessary for processing by the CPU 911.

The ROM 913 stores a BIOS (Basic Input Output System) program, and the magnetic disk device 920 stores a boot program.
When the map drawing device 1201 is activated, the BIOS program in the ROM 913 and the boot program in the magnetic disk device 920 are executed, and the operating system 921 is activated by the BIOS program and the boot program.

  The program group 923 stores programs for executing the functions described as “˜units” in the description of the first to seventh embodiments. The program is read and executed by the CPU 911.

The file group 924 includes map data received from the map data management device 1301.
In the file group 924, in the description of the first to seventh embodiments, “determination of”, “calculation of”, “calculation of”, “comparison of”, “extraction of”, “ Result of processing described as "analysis of", "drawing", "generation of", "update of", "setting of", "registration of", "selection of", etc. Information, data, signal values, variable values, and parameters are stored as items of “˜file” and “˜database”.
The “˜file” and “˜database” are stored in a recording medium such as a disk or a memory. Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or memory are read out to the main memory or cache memory by the CPU 911 via a read / write circuit, and extracted, searched, referenced, compared, and calculated. Used for CPU operations such as calculation, processing, editing, output, printing, and display.
Information, data, signal values, variable values, and parameters are stored in the main memory, registers, cache memory, and buffers during the CPU operations of extraction, search, reference, comparison, calculation, processing, editing, output, printing, and display. It is temporarily stored in a memory or the like.
In addition, the arrows in the flowcharts described in the first to seventh embodiments mainly indicate input / output of data and signals, and the data and signal values are the RAM 914 memory, the FDD 904 flexible disk, the CDD 905 compact disk, and the magnetic field. Recording is performed on a recording medium such as a magnetic disk of the disk device 920, other optical disks, mini disks, DVDs, and the like. Data and signals are transmitted online via a bus 912, signal lines, cables, or other transmission media.

  In addition, what is described as “to part” in the description of the first to seventh embodiments may be “to circuit”, “to device”, “to device”, and “to step”, It may be “˜procedure” or “˜processing”. That is, what is described as “˜unit” may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented only by software, or only by hardware such as elements, devices, substrates, and wirings, by a combination of software and hardware, or by a combination of firmware. Firmware and software are stored as programs in a recording medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD. The program is read by the CPU 911 and executed by the CPU 911. That is, the program causes the computer to function as “to part” in the first to seventh embodiments. Alternatively, the computer executes the procedure and method of “to part” in the first to seventh embodiments.

  As described above, the map drawing device 1201 shown in the first to seventh embodiments includes a CPU as a processing device, a memory as a storage device, a magnetic disk, a keyboard as an input device, a mouse, a communication board, and a display device as an output device, a communication device, and the like. A computer including a board or the like, and implements the functions indicated as “to part” as described above using these processing devices, storage devices, input devices, and output devices.

FIG. 3 is a diagram illustrating an example of a system configuration according to the first embodiment. FIG. 4 is a flowchart showing an operation example of the map drawing apparatus according to the first embodiment. 1 is a diagram illustrating a configuration example of a map drawing apparatus according to Embodiment 1. FIG. FIG. 4 is a flowchart showing an operation example of the map drawing apparatus according to the first embodiment. FIG. 4 shows an example of an unacquired mesh according to the first embodiment. FIG. 4 shows an example of an unacquired mesh according to the first embodiment. FIG. 4 is a flowchart showing an operation example of the map drawing apparatus according to the first embodiment. FIG. 4 shows a screen display example according to the first embodiment. FIG. 4 shows a screen display example according to the first embodiment. FIG. 4 shows a screen display example according to the first embodiment. FIG. 4 shows a screen display example according to the first embodiment. FIG. 4 shows a screen display example according to the first embodiment. FIG. 9 is a flowchart showing an operation example of the map drawing apparatus according to the second embodiment. FIG. 6 shows a screen display example according to the second embodiment. FIG. 6 shows a screen display example according to the second embodiment. FIG. 10 is a flowchart showing an operation example of the map drawing apparatus according to the third embodiment. FIG. 10 shows an example of vector operation according to the third embodiment. The figure which shows the example of a setting of the half line with respect to the road which concerns on Embodiment 3. FIG. The figure which shows the example with which the vector which concerns on Embodiment 3 is parallel, and the example where a vector is not parallel. The figure which shows the example of the table which described the angle of the vector which concerns on Embodiment 3, and the estimated road condition. The figure which shows the example of a setting of the auxiliary curve with respect to the road which concerns on Embodiment 3. FIG. FIG. 10 shows a screen display example according to the fourth embodiment. FIG. 10 shows a screen display example according to the fourth embodiment. FIG. 10 shows a screen display example according to the fourth embodiment. FIG. 10 is a flowchart showing an operation example of the map drawing apparatus according to the fifth embodiment. FIG. 10 shows a screen display example according to the fifth embodiment. FIG. 10 shows a screen display example according to the fifth embodiment. The figure which shows the example of the conventional map display when there exists an unacquired mesh. The figure which shows the area | region division example of the whole Japan which concerns on Embodiment 7. FIG. The figure which shows an example of the specific data structure used for the map data which concerns on Embodiment 7. FIG. The figure which shows the specific example of the point information in the map data which concerns on Embodiment 7, and line information. FIG. 18 shows a specific example of a display area rotation angle according to the seventh embodiment. FIG. 18 shows an example of specific mesh data according to the seventh embodiment. FIG. 20 is a diagram illustrating an example of a specific positional relationship between point information and line information according to the seventh embodiment. The figure which shows the specific example of the road which passes through the several mesh which concerns on Embodiment 7. FIG. The figure which shows the specific data expression example of the road which passes through the several mesh which concerns on Embodiment 7. FIG. FIG. 18 is a diagram showing a specific map drawing example according to the seventh embodiment. The figure which shows the example of the map data acquisition method from the map data management apparatus which concerns on Embodiment 7. FIG. FIG. 9 is a flowchart showing an overall processing flow in a map drawing apparatus according to a seventh embodiment. FIG. 18 is a flowchart showing an overall processing flow of map drawing processing according to the seventh embodiment. FIG. 20 is a diagram for explaining a procedure for deriving a set of mesh identifiers that overlap a drawing area according to the seventh embodiment. FIG. 18 is a diagram for explaining an example of mesh data acquired at the time of route guidance according to the seventh embodiment. The figure which shows the hardware structural example of the map drawing apparatus which concerns on Embodiment 1-7.

Explanation of symbols

  1201 map drawing device, 1202 central control device, 1203 position detection device, 1204 map storage device, 1205 communication device, 1206 map output device, 1207 operation panel, 1208 voice output device, 1211 input unit, 1212 output unit, 1213 map data request Unit, 1214 road extraction unit, 1215 map drawing unit, 1216 notification information generation unit, 1301 map data management device.

Claims (17)

A map drawing device that receives map data in mesh units from a map data management device that manages map data including road displays in mesh units, and draws a map based on the received map data,
When the map data of at least a part of the map data to be transmitted from the map data management device cannot be received, the retained map data held by the map drawing device is analyzed and a specific mesh is analyzed. A road extraction unit that extracts a road that is determined to be the same road as the specific road displayed in FIG.
A map drawing unit for drawing a map for displaying the specific road and the same road extracted by the road extracting unit , using the map data received from the map data management device and the retained map data ;
The specific road and the same road are connected via a mesh missing from the map data management device that cannot receive map data between the mesh from which the same road has been extracted and the specific mesh. When the map drawing unit cannot draw a map indicating a state using the retained map data, a character string or an image for notifying that the specific road and the same road are the same road is designated as the specific road. A map drawing apparatus , comprising: a notification information generating unit that draws in relation to drawing of a road and drawing of the same road . The road extraction unit
Analyzing the retained map data, extracting the same name or the same number as the specific road as the same road,
The notification information generation unit
Character strings or images notifying that the specific road and the same road are roads having the same name or number are drawn in relation to the drawing of the specific road and the drawing of the same road. The map drawing apparatus according to claim 1. The road extraction unit
Analyzing the retained map data, extracting roads with different attributes or names but with similar attributes as the specific roads as different roads,
The map drawing unit
Draw a map that displays the specific road and the heterogeneous road extracted by the road extraction unit;
The notification information generation unit
The specific road and the dissimilar road are connected by a missing mesh in which map data could not be received from the map data management device between the mesh from which the dissimilar road was extracted and the specific mesh. When the map drawing unit cannot draw a map indicating the state even using the retained map data, draw a character string that notifies the name or number of the specific road in relation to the drawing of the specific road, The map drawing apparatus according to claim 1, wherein a character string notifying the name or number of the different road is drawn in relation to the drawing of the different road . The notification information generation unit
A positional relationship between the specific road and the same road or a positional relationship between the specific road and the different road is derived, and a positional relationship between the specific road and the same road or the specific road and the different road. The map drawing apparatus according to claim 3, wherein notification information for notifying a positional relationship between the map drawing apparatus and the map drawing apparatus is generated. The notification information generation unit
A distance between the specific road and the same road, a distance between the specific road and the heterogeneous road, a direction of the same road with respect to the specific road, and the heterogeneous road with respect to the specific road. 5. The map drawing apparatus according to claim 4 , wherein at least one of the location directions is derived, and notification information for notifying at least one of the derived distance and the location direction is generated. The notification information generation unit
The shape of the road connecting the specific road and the same road in the missing mesh interposed between the mesh where the same road or the different road is extracted and the specific mesh, or the specific road and the different road preparative shape of a road guessed that connection, the map drawing device according to claim 3, characterized in that to generate the notification information indicating the shape of the guess guess roads. The map drawing unit
Draw a map with no features displayed in the area corresponding to the missing mesh,
The notification information generation unit
The map drawing apparatus according to claim 6 , wherein the shape of the estimated road is drawn by being superimposed on the area of the missing mesh of the map drawn by the map drawing unit. The map drawing device
Mounted on mobile objects,
The road extraction unit
The mesh corresponding to the current position of the moving body is the specific mesh, the road on which the moving body is moving is the specific road,
The notification information generation unit
A direction vector from the specific road toward the missing mesh and a direction vector from the same road or the heterogeneous road toward the missing mesh are set, the set direction vector is analyzed, and the movement on the specific road deriving a relative direction of the heterologous road to relative direction or relative to the traveling direction of the moving body in the particular road of the same road a traveling direction as a reference body, the relative of the same road The map drawing apparatus according to claim 3, wherein notification information for notifying a specific direction or a relative direction of the heterogeneous road is generated. The notification information generation unit
When a plurality of identical roads are extracted by the road extraction unit, a specific same road is selected from the plurality of the same roads, and the selected same road is extracted between the extracted mesh and the specific mesh. The map according to claim 1 , wherein a shape of a road connecting the specific road and the selected same road is estimated in an intervening missing mesh, and notification information indicating the estimated shape of the estimated road is generated. Drawing device. The notification information generation unit
On the basis of the shape of the guess guess road, the specific extracts Oh Ru road possibility to be connected to infer the road out of the other road other than the same road selected, extracted road via a guessing road The map drawing apparatus according to claim 9 , wherein notification information for notifying that there is a possibility of connection with a road is generated. The map drawing device further includes:
A display unit for displaying the map drawn by the map drawing unit;
An audio output unit for outputting audio information;
The notification information generation unit
Audio information for notifying the association between the specific road and the same road or audio information for notifying the association between the specific road and the different road is generated and generated according to the display of the map by the display unit. The map drawing apparatus according to claim 3, wherein voice information is output to the voice output unit. The map drawing device
Mounted on mobile objects,
The road extraction unit
The current position meshes corresponding to the current position of the movable body and the particular mesh that gives extract the road particular road having the same name or the same number from the holding map data as the same road displayed in the current position mesh The map drawing apparatus according to claim 1 . The road extraction unit
The road where the moving body is currently located is defined as the specific road, and the road having the same name or the same number as the road where the moving body is present is extracted as the same road from the retained map data. The map drawing apparatus according to claim 12 . The map drawing unit
The map drawing apparatus according to claim 3, wherein the map drawing device draws a map that highlights and displays the same road or the different road extracted by the road extraction unit. The road extraction unit
The map drawing apparatus according to claim 3, wherein the same road or the different road is extracted from a mesh adjacent to the missing mesh in the mesh of the retained map data. The map drawing device
Display the map while moving the display range,
At least one of the case where the missing mesh is included in the mesh corresponding to the display target range and the case where the missing mesh is included in the mesh corresponding to the constant range around the display target range, the road extraction unit, a map drawing device according to claim 3, characterized in Rukoto issuing extract the same road or the heterologous road from the holding map data. A program for causing a computer to function as the map drawing device according to claim 1.

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