JP3498081B2 - Information terminal device and map information providing system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information terminal device and a map information providing system, and more specifically, processing such as map display, position detection, route search, and guidance using digital map data. The present invention relates to an information terminal device and a map information providing system.

[0002]

2. Description of the Related Art (First Prior Art) In recent years, the number of vehicles equipped with a navigation system has increased. Such a conventional navigation system is a CD-ROM
A map storage device having a read-only large-capacity storage medium such as a DVD or a ROM is mounted. In addition to the terminal device dedicated to the navigation system, a terminal device for realizing the navigation system is a general-purpose information processing device (PDA: Personal Digital).
It is also realized by Assistants) and the like. Map data to be presented to the user is recorded in advance in these storage media. The storage device reads the map data recorded in the storage medium as necessary, and the read digital map data is used for route search processing or current position correction processing (map matching). For these processes, road network data is recorded in the map data. This road network data stores at least connection information indicating the connection relationship between each node and each link. Where, typically,
A node is information representing an intersection existing on a road network, and a link is vector information representing a road existing between two intersections (nodes). Also, there is a connection relationship between each node and link, and this connection relationship is stored in the road network data as connection information. The road network is represented in the map data by the road network data including such a set of nodes, links, and connection information.

Although a minimum road network can be expressed using the above-mentioned nodes, links, and their connection information, these are not sufficient for the purpose of displaying a map. For example, roads in mountainous areas and coastal areas often have curved roads between intersections. Therefore, the road network data further includes information for specifying the link shape in order to display the shape of the curved road.

There are various types of roads such as national roads and prefectural roads. In addition, roads can be classified according to the difference in the number of lanes or the presence or absence of a median strip. In order to distinguish such road types, the road network data further includes attribute information indicating road types and the like.

Further, there are some road intersections with or without an intersection name. Furthermore, there are intersections with traffic lights and intersections without traffic lights. Therefore, the road network data has attribute information for each node. In the attribute information for each node, information such as the name of the intersection and the presence / absence of a traffic light corresponding to each node is recorded.

(Second Prior Art) As described in the above first prior art, the conventional navigation system could only use the map data recorded in the read-only storage medium at first, so that the real-time property was obtained. It was difficult to provide high quality information. For example, traffic information and meteorological information are typical examples of the information with high real-time property. Therefore, a map providing system that can provide the information and map data that requires the real-time property is disclosed in, for example, Japanese Patent Laid-Open No. 7-262493.
In the map providing system, highly real-time information and map data are downloaded from an information providing center (center station) to a vehicle-mounted terminal device via a communication medium. Also, in a terminal device having a small data storage capacity such as a general-purpose information processing device (PDA, mobile phone terminal, etc.),
In order to implement the navigation system described above, the map data may be downloaded from the center station to the information terminal device as needed.

The map providing system is constructed based on mobile communication technology and digital broadcasting technology in order to provide various kinds of information in real time. In such a map providing system, the center station distributes information to mobile terminals existing in the service area using a predetermined broadcasting channel. As the center station, a communication satellite (CS), a broadcasting satellite (BS), or a terrestrial digital broadcasting station is typical. A map providing system using such mobile communication technology and digital broadcasting technology is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-154350. The official gazette discloses technical contents for limiting the broadcasting area of certain information.

In the map providing system disclosed in the publication, the center station adds a region code such as a postal code to the information when transmitting the multiplexed information via the broadcast medium. On the other hand, the receiving terminal device registers the area code corresponding to its current position as an ID in the memory in advance. Inside the terminal device, a data extraction circuit separates the multiplex information distributed from the center station and extracts the area code added to the information. Furthermore, inside the terminal device, the ID registered in advance in the memory is compared with the extracted area code. If the two match, the terminal device causes the user to refer to the information with the target area code.

As described above, a map providing system for providing map data to a terminal device by using communication or broadcasting has been actively developed in recent years. In such a map providing system, the center station transmits map data to the terminal device, the terminal device receives the map data from the center station, and then stores the map data in the storage device. The stored map data is used by the user for browsing, route search processing, map matching processing, or the like as necessary.

[0010]

As described in the first prior art, road networks are conventionally represented by nodes and links, and connection information between them is recorded in advance in map data. This is for reading the connection information of the road network data in the map data at high speed and efficiently in the map matching process, the route search process and the like. However, since the connection information between nodes and links is recorded in detail in the map data, the data capacity of the map data becomes very large.

Here, the outline of the processing for carrying out route search and map matching using the map data will be described. FIG. 11 is a schematic diagram showing an example of nodes and links represented by the map data.

In FIG. 11, the road network represented by the map data is composed of eight nodes N1 to N8 and twelve links L1 to L12. When performing map matching processing or route search processing using such a road network, it is necessary to trace the connection relationship between nodes and links. For example, the shortest route from the node N1 to the node N8 is the node N1 →
In the case of a route that follows the order of link L2 → node N3 → link L6 → node N5 → link L9 → node N6 → link L11 → node N8, it is necessary to follow the following procedure.

Procedure 1: Two links are connected to the node N1, one of which is the link L2 Procedure 2: The link L2 is connected to the node N3 Procedure 3: To the node N3 5 links are connected,
One of them is the link L6 Procedure 4: The link L6 is connected to the node N5 Step 5: Three links are connected to the node N5,
One of them is the link L9 Step 6: The link L9 is connected to the node N6 Step 7: Four links are connected to the node N6,
One of them is the link L11 Procedure 8: The link L11 is connected to the node N8 That is, the connection information from the node indicating the link connected to each node is required (Procedure 1 3, 5, 7), and link-to-node connection information indicating the nodes connected to each link is required (procedures 2, 4, 6, 8).

Road network data for tracing a route will be described using the connection information between the nodes and links. FIG. 12 is an example of a data structure of a road network expressing the road network.

In FIG. 12, as the road network data, a node table in which eight node records in which information corresponding to eight nodes N1 to N8 are recorded and information corresponding to twelve links L1 to L12 are recorded. The link table includes 12 link records. Each node record in the node table stores data representing node attribute information and coordinate information. Further, in each of the node records, link pointer information for indicating the number of links connected to the node and the location where the link record corresponding to each link connected to the node is stored in the link table. Is stored (the number of links and pointer information of the links correspond to the above-mentioned connection information from the node to the link).

On the other hand, each link record of the above link table stores data representing link attribute information. Further, in each of the link records, pointer information of a node for indicating a location where the node record corresponding to each node connected to the link is stored in the node table (this node is stored) Pointer information corresponds to the above-mentioned connection information from the link to the node).

By having such a data structure,
Since it is possible to easily find what kind of link is connected to any node, and what kind of node is connected to any link, it is possible to easily follow the route in the road network. is there. However, it is necessary to record the pointer information of links corresponding to the number of links connected to the node in each node record of the node table having such a data structure. Similarly, it is necessary to record pointer information of two nodes corresponding to both end nodes in each link record of the above link table. As a result, more information is needed to represent the road network, and the wider the map range represented by the road network data, such as the representation of maps of all over Japan,
The data capacity will be enormous. Further, in a general-purpose information processing device (PDA, mobile phone terminal, etc.) having a small data storage capacity, further reduction of the data capacity of the map data is required.

Further, also in the map providing system described in the second prior art, since the map data distributed from the center station to the terminal device is based on the above-mentioned data structure, it is transmitted from the center station to the terminal device. There is a problem that the capacity of the map data to be used becomes large and the time and cost required for the data transfer increase.

Therefore, it is an object of the present invention to provide an information terminal device and a map information providing system which reduce the capacity of map data without impairing the function of an application using digital map data.

[0020]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the present invention has the following features. A first invention is an information terminal device for processing map data including node data indicating a road intersection as a node and link data indicating a road as a link, and a map data storage unit for storing the map data, A map data processing unit for processing the map data stored in the data storage unit, wherein the map data stored in the map data storage unit is connected to one of the nodes and the link as seen from the other side. Only the one-sided connection information indicating the relationship is described, and the map data processing unit
Based on the map data reading unit that reads the map data necessary for processing from the map data storage unit and the one-sided connection information described in the map data read by the map data reading unit, either the node or the other link The other side connection information complementing section that newly generates the other side connection information indicating the connection relationship when viewing one side from the side and complements the read map data, and the other side connection information is complemented. And a map data calculation processing unit that performs a predetermined calculation process on the map data.

According to the first aspect of the present invention, the map data stored in the map data storage unit is either one of a node and a link constituting a road network necessary for performing position detection processing and route search processing. Since only the one-sided connection information indicating the connection relationship when viewing one side from the other side is described, the data capacity of the map data can be reduced. Therefore, the range of map data that can be stored in the map data storage unit can be widened, and the capacity of the map data storage unit can be reduced. Further, the map data processing unit, on the basis of the one-sided connection information for the map data that needs to be processed, the other side connection indicating the connection relation when one side is viewed from the other side of the node and the link. Since the information is newly generated, the connection relation of the road network can be traced even when the position detection processing or the route search processing using the map data is performed without impairing the processing efficiency.

A second invention is an invention dependent on the first invention, and in the map data stored in the map data storage unit, only the node connection information indicating the connection relationship of the nodes viewed from the link is It is described as the side connection information, and the other side connection information complementing section indicates the connection relationship of the links seen from the node based on the node connection information described in the map data read by the map data reading section. The link connection information is newly generated as the other side connection information, and the read map data is complemented.

According to the second aspect of the present invention, the map data stored in the map data storage unit is the connection between the nodes and the links constituting the road network required for the position detection process and the route search process. Of the information, only the node connection information for tracing the connection from the link to the node is recorded, so that the data capacity of the map data can be reduced. In addition, since the connection information for tracing the connection from the node to the link generally requires a larger amount of data than the connection information for tracing the connection from the link to the node, the data capacity of the above map data is large. Can be reduced. As a result, the range of map data that can be stored in the map data storage unit can be widened, and the capacity of the map data storage unit can be reduced. Further, the map data processing unit performs position detection processing and route search processing using the map data in order to newly generate link connection information from the omitted node to the link for the map data that needs processing. Also in this case, the connection relationship of the road network can be traced without impairing the processing efficiency.

A third invention is according to the first invention, and in the map data stored in the map data storage unit, only the link connection information indicating the connection relationship of the links viewed from the node is stored. It is described as the side connection information, and the other side connection information complementing section indicates the connection relationship of nodes viewed from the link based on the link connection information described in the map data read by the map data reading section. The node connection information is newly generated as the other side connection information, and the read map data is complemented.

According to the third aspect of the present invention, the map data stored in the map data storage unit is the connection between the nodes and the links that form the road network, which is necessary when performing the position detection process and the route search process. Since only the link connection information for tracing the connection from the node to the link is recorded in the information, the data capacity of the map data can be reduced. As a result, the range of map data that can be stored in the map data storage unit can be widened, and the capacity of the map data storage unit can be reduced. In addition, the map data processing unit performs position detection processing and route search processing using the map data in order to newly generate node connection information from the omitted link to the node for the map data that needs processing. Also in this case, the connection relationship of the road network can be traced without impairing the processing efficiency.

According to a fourth aspect of the present invention, the center station transmits via at least one information terminal device that processes map data including node data indicating road intersections as nodes and link data indicating roads as links. In the map information providing system for providing the map data, the center station stores the first map data storage unit for storing the map data and the map data requested by the information terminal device in the first map data storage unit. A map data transmitting unit that reads the map data from the center station and transmits the map data to the information terminal device via a transmission line. The information terminal device receives the map data transmitted from the center station via the transmission line. A receiver,
The second for storing the map data received by the map data receiving section
Map data storage unit and a map data processing unit for processing the map data stored in the second map data storage unit, and the map data transmitted from the center station includes either the node or the link. Only the one-sided connection information indicating the connection relationship when viewing the other side from
The map data processing unit is based on the map data reading unit that reads the map data necessary for processing from the second map data storage unit and the one-sided connection information described in the map data read by the map data reading unit. And the other side connection information complementing unit that newly generates the other side connection information indicating the connection relationship when viewing one side from the other side of the node and the link and complements the read map data. And a map data calculation processing unit that performs a predetermined calculation process on the map data supplemented with the other side connection information.

According to the fourth aspect of the present invention, the map data stored in the first map data storage unit is composed of the nodes and links constituting the road network necessary for performing the position detecting process and the route searching process. Since only the one-sided connection information indicating the connection relationship when the one side is viewed from the one side is described, the data capacity of the map data can be reduced. Therefore, the range of map data that can be stored in the first map data storage unit can be widened, and the capacity of the first map data storage unit can be reduced. In addition, when the center station transmits the map data stored in the first map data storage unit to the information terminal device via the transmission path, since the capacity of the map data to be transmitted is small, the transmission is not possible. The time required can be reduced. Furthermore, when the information terminal device receives the map data transmitted via the transmission path and then stores the map data in the second map data storage unit, since the capacity of the received map data is small, the second map data is stored. The range of map data that can be stored in the data storage unit can be widened, and the capacity of the second map data storage unit can be reduced. Further, the map data processing unit, on the basis of the one-sided connection information for the map data that needs to be processed, the other side connection indicating the connection relation when one side is viewed from the other side of the node and the link. Since the information is newly generated, the connection relation of the road network can be traced even when the position detection processing or the route search processing using the map data is performed without impairing the processing efficiency.

A fifth invention is an invention according to the fourth invention, and in the map data transmitted from the center station, only the node connection information indicating the connection relationship of the nodes viewed from the link is connected on one side. The link connection, which is described as information, is based on the node connection information described in the map data read by the map data reading unit, and the other side connection information complementing unit indicates the link connection showing the connection relationship of the links viewed from the node. Information is newly generated as connection information on the other side, and the read map data is complemented.

According to the fifth aspect of the present invention, the map data stored in the first map data storage unit is composed of the nodes and links constituting the road network necessary for the position detection processing and the route search processing. Since the data structure is such that only the node connection information for tracing the connection from the link to the node is recorded among the connection information between the nodes, the data capacity of the map data can be reduced. In addition, since the connection information for tracing the connection from the node to the link generally requires a larger amount of data than the connection information for tracing the connection from the link to the node, the data capacity of the above map data is large. Can be reduced. As a result, the range of map data that can be stored in the first map data storage unit can be widened, and the capacity of the first map data storage unit can be reduced. In addition, when the center station transmits the map data stored in the first map data storage unit to the information terminal device via the transmission path, since the capacity of the map data to be transmitted is small, the transmission is not possible. The time required can be reduced. Furthermore, when the information terminal device receives the map data transmitted via the transmission path and then stores the map data in the second map data storage unit, since the capacity of the received map data is small, the second map data is stored. It is possible to widen the range of map data that can be stored in the data storage unit,
It is also possible to reduce the capacity of the second map data storage unit. Further, the map data processing unit performs position detection processing and route search processing using the map data in order to newly generate link connection information from the omitted node to the link for the map data that needs processing. Also in this case, the connection relationship of the road network can be traced without impairing the processing efficiency.

A sixth invention is an invention subordinate to the fourth invention, and in the map data transmitted from the center station, only the link connection information showing the connection relationship of the links seen from the node is connected on one side. The connection information complementing section on the other side is a node connection indicating the connection relationship of the nodes viewed from the link, based on the link connection information described in the map data read by the map data reading section. Information is newly generated as connection information on the other side, and the read map data is complemented.

According to the sixth aspect of the present invention, the map data stored in the first map data storage unit is composed of the nodes and links constituting the road network necessary for performing the position detection processing and the route search processing. Of the connection information between the nodes, only the link connection information for tracing the connection from the node to the link is recorded, so that the data capacity of the map data can be reduced. As a result, the range of map data that can be stored in the first map data storage unit can be widened, and the capacity of the first map data storage unit can be reduced. In addition, when the center station transmits the map data stored in the first map data storage unit to the information terminal device via the transmission path, since the capacity of the map data to be transmitted is small, the transmission is not possible. The time required can be reduced. Furthermore, when the information terminal device receives the map data transmitted via the transmission path and then stores the map data in the second map data storage unit, since the capacity of the received map data is small, the second map data is stored. It is possible to widen the range of map data that can be stored in the data storage unit,
It is also possible to reduce the capacity of the second map data storage unit. In addition, the map data processing unit performs position detection processing and route search processing using the map data in order to newly generate node connection information from the omitted link to the node for the map data that needs processing. Also in this case, the connection relationship of the road network can be traced without impairing the processing efficiency.

A seventh aspect of the present invention is a program for causing a computer to process map data including node data indicating a road intersection as a node and link data indicating a road as a link, and storing the map data. A map data storing step and a map data processing step for processing the map data stored in the map data storing step are included, and the map data stored in the map data storing step includes a node and a link from one side. Or only one side connection information indicating the connection relationship when looking at the other side is described. The map data processing step includes a map data reading step for reading map data necessary for processing from the map data storing step and a map data reading step. While described in the map data read by Based on the connection information, the other side that newly generates the other side connection information indicating the connection relationship when viewing one side from the other side of the node and the link, and complements the read map data. It includes a connection information complementing step and a map data operation processing step of performing a predetermined operation processing on the map data with the other side connection information complemented.

An eighth invention is according to the seventh invention, and in the map data stored in the map data storing step, only the node connection information indicating the connection relationship of the nodes viewed from the link is It is described as the side connection information, and the other side connection information complementing step indicates the connection relationship of the links viewed from the node based on the node connection information described in the map data read by the map data reading step. The link connection information is newly generated as the other side connection information, and the read map data is complemented.

A ninth invention is according to the seventh invention, and in the map data stored in the map data storing step, only the link connection information indicating the connection relationship of the links viewed from the node is stored. It is described as the side connection information, and the other side connection information complementing step indicates the connection relationship of the nodes viewed from the link based on the link connection information described in the map data read by the map data reading step. The node connection information is newly generated as the other side connection information, and the read map data is complemented.

In a tenth aspect of the present invention, map data including node data indicating a road intersection as a node and link data indicating a road as a link is provided from a center station via a transmission line, and the map data is processed. A program to be executed by a computer, a map data receiving step of receiving map data transmitted from a center station via a transmission line, and a map data storing step of storing the map data received in the map data receiving step. And a map data processing step for processing the map data stored in the map data storage step, wherein the map data stored in the map data storage step includes one side of the node and the other side of the map. Only the one-sided connection information showing the viewed connection relationship is described, and the map data processing step Is a node or a link based on the map data reading step that reads the map data necessary for processing from the map data storing step and the one-sided connection information described in the map data read by the map data reading step. Or the other side connection information complementing step of newly generating the other side connection information indicating the connection relationship when viewing one side from the other side and complementing the read map data, and the other side connection information A map data calculation processing step of performing a predetermined calculation processing on the complemented map data.

An eleventh invention is an invention dependent on the tenth invention, and in the map data transmitted from the center station, only the node connection information indicating the connection relationship of the nodes viewed from the link is connected on one side. The other side connection information complementing step is described as information, and the link connection indicating the connection relationship of the links viewed from the node based on the node connection information described in the map data read by the map data reading step. Information is newly generated as connection information on the other side, and the read map data is complemented.

The twelfth invention is an invention dependent on the tenth invention, and in the map data transmitted from the center station, only the link connection information showing the connection relationship of the links seen from the node is connected on one side. The other side connection information complementing step is described as information, and the node connection indicating the connection relationship of the nodes viewed from the link is based on the link connection information described in the map data read by the map data reading step. Information is newly generated as connection information on the other side, and the read map data is complemented.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) "Device Configuration" FIG. 1 is a diagram showing a hardware configuration of an information terminal device according to a first embodiment of the present invention and a function formed by executing a program. It is a functional block diagram which shows a structure. The information terminal device 1 is typically a car navigation device that is installed in a vehicle and used exclusively, or a general-purpose P
DA (Personal Digital Assist)
tans). The above program is
It is also possible to include it in an appropriate medium, and it is also possible to port the same function by installing the above program in another information terminal device.

In FIG. 1, the information terminal device 1 includes a first input unit 11, a position detection unit 12, a first arithmetic processing unit 13,
A data storage unit 15, a first data reading unit 18, a connection information generation unit 17, and a first output unit 16 are provided.

For example, when the information terminal device 1 is a car navigation device, the first input unit 11 is realized in hardware by a key arranged on a remote controller or a car navigation device main body for remotely operating the car navigation device. Alternatively, it is configured by software with buttons displayed on the menu screen of the car navigation device. Further, the first input unit 11 may be realized by a voice input device that makes full use of voice recognition technology. The user of the information terminal device 1 operates the first input unit 11 to request the information terminal device 1 for various processes such as information display selection and information search.

The position detector 12 is a speed sensor, a gyro sensor, or a GPS (Global Position).
Ning System) receiving antenna and receiver. Further, the position detection unit 12 may be configured by a combination of two or more of a speed sensor, a gyro sensor, and a GPS receiving antenna and a receiver. The speed sensor detects the moving speed of the information terminal device 1 and calculates the traveling distance based on the detection result, the gyro sensor detects the traveling direction of the information terminal device 1, the GPS receiving antenna and the receiver. By receiving the radio wave from the artificial satellite, the position detection unit 12 detects the absolute position of the information terminal device 1 on the earth based on the information. Further, based on the input from each of these sensors, the road network data stored in the data storage unit 15 may be used to perform a map matching process for correcting the current position to a position on the road.
The position detection unit 12 detects the current position of the information terminal device 1 based on the above detection result. In the process described later, when the information terminal device 1 performs only the process that does not require the current position data, the position detecting unit 12 is unnecessary.

The first arithmetic processing section 13 carries out various data processing described later. For example, the process of the first arithmetic processing unit 13 includes a guide guidance process for reading out map data, which will be described later, stored in the data storage unit 15 and guiding the vehicle equipped with the information terminal device 1 or the user. .

The data storage section 15 is typically composed of a rewritable storage medium such as a hard disk drive or a flash memory.
Map data is stored in the data storage unit 15, and this map data is used for position detection, guidance, and the like. The detailed contents of the map data stored in the data storage unit 15 will be described later.

The first data reading section 18 performs a process of reading necessary map data from the data storage section 15.

The connection information generation unit 17 performs processing for complementing and generating the road network connection information for the map data read by the first data reading unit 18. Detailed contents of the connection information complementing and generating process performed by the connection information generating unit 17 will be described later. In the first arithmetic processing unit 13, various data processing such as route search and position detection processing is mainly performed by using the connection information of the road network complemented and generated by the connection information generation unit 17.

The first output section 16 is typically composed of a display device and a speaker. On the display device, a map is displayed together with the current position or guidance information is displayed. The speaker provides the guidance information to the user by voice.

The configuration of the information terminal device 1 has been described above. Hereinafter, the data structure of the map data used in such an information terminal device 1 will be described.

"Data structure of map data" FIGS. 2 to 4
FIG. 3 is a diagram showing a data structure of map data used in the information terminal device 1. In FIG. 2, the map data used in the information terminal device 1 is divided into rectangular units of 450 seconds in the longitude direction and 300 seconds in the latitude direction (hereinafter referred to as units) when representing the whole of Japan. . Each of the units is configured as file data (hereinafter referred to as unit data), and preferably, a file system to which a unit data name capable of uniquely specifying the longitude and latitude coordinates corresponding to each unit is assigned. Managed by. For example, 135 east longitude
For a unit that includes points at 34 ° 31'34 ° and 34 ° 44'31 ° N, the quotient 1084 obtained by dividing 135 ° 34'31'E by 450 sec.
A unit data name "E1084N416.map" is assigned using a quotient 416 obtained by dividing 4 minutes 31 seconds by a division size of 300 seconds in the latitude direction. In the unit data name, "E" represents east longitude and "N" represents north latitude.
By assigning such unit data names to the above units, it is possible to easily know the longitude and latitude range covered by each unit, and conversely, for the given longitude and latitude coordinate point, that point It is possible to easily specify a unit including.

Further, each of the above unit data is
It has a data structure as shown in FIG. In FIG. 3, the unit data includes unit management information, a background table, a character table, a node table, and a link table.

The unit management information is information for managing the above unit data as a whole, and more specifically, each unit of the background table, the character table, the node table, and the link table is stored from the beginning of the unit data. The offset information indicating whether or not it is recorded in the byte is stored. With this unit management information, a desired table can be easily read from the unit data.

The background table is mainly used for displaying map data in the first output section, such as green space data such as parks and forests, facility data such as factories and airports, and water system data such as seas and rivers. The map background data other than the road network are mainly stored as polygon data.

The character table mainly stores character string data such as a place name, an intersection name, a road name, and a facility name, which are necessary when displaying map data or performing guidance processing.

In the present embodiment, the background table and the character table do not have the characteristics peculiar to the present invention and will not be described in further detail.

The node table is a table that mainly stores road intersections (hereinafter referred to as nodes) as node data of road network data, and the link table mainly stores roads that connect road intersections (hereinafter referred to as "nodes"). A link) is stored as link data of road network data. Hereinafter, the node table and the link table will be described in detail.

In order to explain the above-mentioned node table and link table, an example of a road network will be described first. For example, the road network may be the one shown in FIG.
8 nodes N1-N8 and 12 as shown in FIG.
It is assumed that the book includes links L1 to L12. When the information terminal device 1 performs a map matching process or a route search process using such a road network, it is necessary to trace the connection relationship between nodes and links.
For example, the shortest route starting from the node N1 and reaching the node N8 is node N1 → link L2 → node N3 → link L6 → node N5 → link L9 → node N6 → link L
If the route follows the order of 11 → node N8, it is necessary to follow the route according to the following procedure.

Procedure 1: Two links are connected to the node N1, one of which is the link L2 Procedure 2: The link L2 is connected to the node N3 Procedure 3: To the node N3 5 links are connected,
One of them is the link L6 Procedure 4: The link L6 is connected to the node N5 Step 5: Three links are connected to the node N5,
One of them is the link L9 Step 6: The link L9 is connected to the node N6 Step 7: Four links are connected to the node N6,
One of them is the link L11 Step 8: The link L11 is connected to the node N8 That is, in order to detect the shortest route from the node N1 to the node N8 in the road network shown in FIG. Requires connection information from the node indicating the link connected to each node to the link (procedures 1, 3, 5, 7), and the node connected to each link must be specified. Connection information from the indicated link to the node is required (procedures 2, 4, 6, 8).

FIG. 4 shows an example of the data structure of the node table and the link table stored as the road network data of the road network shown in FIG.
In FIG. 4, the node table includes eight nodes N1.
8 node records that record information corresponding to N8 are described. Further, 12 link records in which information corresponding to 12 links L1 to L12 are recorded are described in the link table.

Each node record described in the node table stores data representing the attribute information and the coordinate information of the node. On the other hand, each link record described in the link table stores data representing link attribute information. Further, each link record stores pointer information to the node record for indicating the location where the node record corresponding to each node connected to the link is stored in the node table (this The pointer information to the node record corresponds to the connection information from the link to the node described above). For example, in FIG.
In the road network shown in, since the nodes N1 and N3 are connected to the link L2, the pointer information to the nodes N1 and N3 is described in the pointer information of the link record of the link L2.

As described above, the data structure of the map data used in the information terminal device 1 includes the number of links connected to the node and each link connected to the node in each node record described in the node table. The link pointer information for indicating the location where the link record corresponding to is stored in the link table is not described. That is, the connection information from the node to the link, which corresponds to the link number and pointer information to the link, is not described. Therefore, compared with the conventional map data as shown in FIG. 12 of the conventional technique, the data capacity for expressing the road network can be dramatically reduced.

However, with the map data in which the data structure of this node table is described, the processing efficiency is low when tracing the connection relationship between nodes and links in the map matching processing and route search processing, so the map data described above is used. When the connection information is read out from the data storage unit 15 to the main memory, the connection information is loosened into a data structure that is easier to follow before use. The data structure and procedure for expanding such map data on the main memory will be described later.

The configuration of the information terminal device 1 embodying the information terminal device 1 and the data structure of the map data have been described above. Hereinafter, the procedure of detailed processing of the information terminal device 1 will be described.

[Procedure of Processing of Information Terminal Device 1] As described above, the information terminal device 1 is typically a car navigation device or a PDA. As is well known, a vehicle-mounted car navigation device executes map matching, route search, and guidance processing. Hereinafter, of these processes, the procedure of the process when the information terminal device 1 reads the map data will be described in detail by taking the route search process as an example.

In the road network shown in FIG. 11,
When obtaining the shortest route to the node N8 with the node N1 as the departure point, the information terminal device 1 uses the nodes N1 to N1.
The arrival costs of all the combination routes up to 8 are obtained, and the combination having the smallest arrival cost is selected. In order to obtain such an arrival cost, it is necessary to be able to sequentially trace the mutual connection relationship of all the nodes and links configuring the road network by the map data.

The data structure of the map data used in the information terminal device 1 is as described in "Data structure of map data" with reference to FIGS. However, with the data structure as shown in FIG. 4 (that is, the pointer information from the node record to the link record is not described in the node table), the node N of the road network shown in FIG.
1 → link L2 → node N3 → link L6 → node N5
→ link L9 → node N6 → link L11 → node N8
If you try to follow the route that leads to, the processing efficiency is not good. This is because each link record described in the link table of FIG. 4 records information about which node is connected to both ends of the link, but each node record described in the node table. This is because information about what kind of links are connected to each node is not recorded in the. Therefore, in order to follow the connection between the node and the link as described above, the information terminal device 1 searches the link table many times each time the node is reached, and finds the link connected to the node. It becomes necessary to search, and the efficiency becomes poor when a process such as a route search process that frequently finds a connection relationship between nodes and links is performed.

Therefore, when the information terminal device 1 uses the map data in the route search processing or the like, after the map data is read from the data storage unit 15 through the first data reading unit 18, the connection information generation unit is read. In 17, the data structure is developed into a data structure that makes it easy to trace the connection relationship between the nodes and links, and the data structure is arranged in the main memory.

Regarding the expansion into such a data structure,
A procedure of processing when the connection information generation unit 17 of the information terminal device 1 reads the map data will be described. Figure 5
FIG. 6 is a flowchart showing a procedure in which the connection information generating unit 17 processes the map data read by the first data reading unit 18.

In FIG. 5, the connection information generating section 17 refers to the head node record described in the node table of the map data read by the first data reading section 18 (step S101). For example, in the case of the data structure of the node table shown in FIG. 4, the connection information generation unit 17 refers to the node record corresponding to the node N1.

Next, the connection information generator 17 refers to the head link record described in the link table (step S102). For example, in the case of the data structure of the link table shown in FIG. 4, the connection information generation unit 17 uses the link L1.
Refer to the link record corresponding to.

Next, the connection information generation unit 17 determines whether or not pointer information to the referenced node record is described in the referenced link record (step S103). For example, when the link record corresponding to the link L1 is referenced with respect to the node record corresponding to the node N1 shown in FIG. 4, the connection information generating unit 1
7 determines that the pointer information to the referenced node record is described in the referenced link record. Then, the connection information generating unit 17 performs the above step S
If it is determined that pointer information to the node record referenced in the link record referenced in 103 is described, the process proceeds to the next step S104, and if it is determined that it is not described, the next step The process proceeds to S105.

Next, the connection information generating unit 17 counts up the counter for counting the number of links connected to the node corresponding to the node record with respect to the referenced node record, and refers to the referenced link. The pointer information to the record is described (step S104). For example,
When the link record corresponding to the link L1 is referred to for the node record corresponding to the node N1 illustrated in FIG. 4, the connection information generation unit 17 determines the number of connection links for the referred node record. +1 and the pointer information to the link L1 is described.

Next, the connection information generator 17 determines whether or not the referenced link record is the last record in the link table (step S105). And
When the link record is the final record, the connection information generation unit 17 advances the processing to the next step S107,
If the link record is not the final record, the next link record is referred to (step S106), and the process returns to step S103.

Next, the connection information generator 17 determines whether or not the referenced node record is the last record in the node table (step S107). And
If the node record is the final record, the connection information generation unit 17 ends the process according to the flow. If the node record is not the final record, the connection information generation unit 17 refers to the next node record (step S108), and proceeds to step S102. Return.

The above-mentioned processing is executed by the connection information generation unit 17
Is repeated up to the end of the node table, the number of links connected to each node and pointer information to the link record to be connected can be acquired. By this processing, the node table shown in FIG.
It is described in the data format as shown in. That is, by the above-described processing, the data structure is expanded to the same data structure as the node table described in the related art, and the connection information generation unit 17 arranges the node table having such a data format in the main memory. be able to. In this way, if the connection information generation unit 17 arranges it on the main memory in the same data format as the node table and the link table shown in FIG. 12 described in the conventional technique, the subsequent processing is the first arithmetic processing. As shown in the above-mentioned conventional technique, the unit 13 can efficiently trace the connection information between the node and the link, and can perform the route search processing and the like at high speed. A method such as the Dijkstra method is used for the route search processing, and the content of the processing is already known. Therefore, further description will be omitted in the present embodiment.

In addition to the route search process, the information terminal device 1 also performs a map matching process for correcting and arranging the current position of the information terminal device 1 on the road network of map data, and a route search process. Using the results of processing and the results of map matching, processing such as guidance from the departure point to the destination is performed, but when performing these processing, when reading the map data into the main memory as described above. In addition, since the connection information generation unit 17 expands the connection information of the road network into a data format that is easy to trace and then uses, the processing can be performed efficiently. The detailed contents of the map matching processing and the guidance processing are also omitted because they do not have the characteristics peculiar to the present invention.

As described above, when the road network of digital map data is recorded in the data storage unit 15, only the minimum necessary connection information is recorded and stored, so that the data capacity of the map data is minimized. Can be suppressed to. Furthermore, using such digital map data,
When performing processing for tracing road connection relationships such as map matching and route search, the above map data is stored in the data storage unit 1.
After the data is read from No. 5 via the data reading unit 18, the connection information generation unit 17 expands it into a data structure capable of efficiently tracing the road connection relationship and arranges it in the main memory. As a result, in order to reduce the data capacity, it is possible to use the map data without impairing the processing performance in the map matching, route search processing, etc., although the connection information recorded in the map data is simplified. it can.

In the present embodiment, the data storage unit 15 for recording map data is a rewritable storage medium such as a hard disk or a flash memory, but it is a read-only CD-ROM or DVD-ROM. You may use the medium of.

Further, in the description of the present embodiment, an example of the data structure of the node table and the link table is shown, but the data structure is not necessarily limited to the data structure shown in the present embodiment, and a data structure having similar functionality is provided. So long as it is in any format.

In the first embodiment, the car navigation device and the PDA have been described as an example of the information terminal device 1. However, the present embodiment can also be applied to applications in which a database of map data is created in a personal computer and the personal computer displays a map or conducts route search. That is, the technical field of the present invention can be applied not only to a movable terminal device but also to a general-purpose stationary terminal device. In this case, the position detection unit 12 described above
Does not have to be.

Further, in the first embodiment, as the data structure of the map data, regarding the connection relationship between the nodes and the links constituting the road network, only the connection information from the link to the node is recorded in the map data. Then, when the map data is read, the connection information from the link to the node described in the link table is used to generate and use the connection information from the node to the link in the node table. This is because the connection information for tracing the connection from the node to the link generally requires a larger amount of data than the connection information for tracing the connection from the link to the node. Many can be reduced. However, if such an effect is not expected, only the connection information from the node to the link is recorded in the above map data, and when the map data is read out,
The connection information from the link to the node may be generated and used in the link table using the connection information from the node to the link described in the node table.

(Second Embodiment) "System Configuration" FIG. 7 is formed by executing a hardware configuration of an information terminal device and a map information providing system according to a second embodiment of the present invention, and executing a program. It is a block diagram showing functional composition. Information terminal device 1
Is typically realized by a car navigation device that is installed in a vehicle and used exclusively, or a general-purpose PDA and a mobile phone terminal device. The program can be included in an appropriate medium, and the same function can be ported by installing the program in another information terminal device.

In FIG. 7, the map information providing system comprises an information terminal device 1 and a center station 2. The information terminal device 1 and the center station 2 are connected via a communication network 3 so as to be capable of bidirectional communication. More specifically, an uplink UL and a downlink DL are formed between the information terminal device 1 and the center station 2. The uplink UL means a communication path from the information terminal device 1 to the center station 2, and the downlink DL means a communication path from the center station 2 to the information terminal device 1. Here, as a typical example of the communication network 3, a mobile communication network represented by a mobile phone,
ISDN (Integrated Services)
There is a public line or a dedicated line represented by Digital Network). The communication network 3 is any one of the mobile communication network, the public line, and the dedicated line 2
It may be composed of more than one. When accessing the center station 2 from the information terminal device 1, the information terminal device 1 may be directly connected to the center station 2 via these communication networks 3, but through the access point. ISP (Internet Service)
A general method is to connect to the Provider) and indirectly access the center station 2. At this time, the communication protocol of the information terminal device 1 and the ISP is generally PP.
P (Point-to-Point Protocol)
l) is used. The use of PPP enables the exchange of Internet standard TCP / IP packets. Therefore, the data transmitted and received on the uplink UL from the information terminal device 1 to the center station 2 and the downlink DL from the center station 2 to the information terminal device 1 are TC
It is accommodated in a P / IP packet. In order to simplify the following description, well-known matters such as PPP and TCP / TCP /
Description of detailed processing based on IP is omitted.

Next, the configuration of the information terminal device 1 will be described. The information terminal device 1 includes a first input unit 11, a position detection unit 12, a first arithmetic processing unit 13, a first communication unit 14, a data storage unit 15, a first data reading unit 18, and a connection information generation unit. A data writing unit 17, a data writing unit 19, and a first output unit 16 are provided.

When the information terminal device 1 is a car navigation device, for example, the first input unit 11 is realized in hardware by a remote controller for remotely operating the car navigation system or a key arranged in the car navigation device body. Alternatively, it is configured by software with buttons displayed on the menu screen of the car navigation device. Further, the first input unit 11 may be realized by a voice input device that makes full use of voice recognition technology. The user of the information terminal device 1 uses the above first input unit 1
1 is operated to request the information terminal device 1 to perform various processes such as information display selection, information retrieval, and connection to the center station 2.

The position detector 12 is a speed sensor, a gyro sensor, or a GPS (Global Position).
Ning System) receiving antenna and receiver. Further, the position detection unit 12 may be configured by a combination of two or more of a speed sensor, a gyro sensor, and a GPS receiving antenna and a receiver. The speed sensor detects the moving speed of the information terminal device 1 and calculates the traveling distance based on the detection result, the gyro sensor detects the traveling direction of the information terminal device 1, the GPS receiving antenna and the receiver. By receiving the radio wave from the artificial satellite, the position detection unit 12 detects the absolute position of the information terminal device 1 on the earth based on the information. Further, based on the input from each of these sensors, the road network data stored in the data storage unit 15 may be used to perform a map matching process for correcting the current position to a position on the road.
The position detection unit 12 detects the current position of the information terminal device 1 based on the above detection result. In the process described later, when the information terminal device 1 performs only the process that does not require the current position data, the position detecting unit 12 is unnecessary.

The first arithmetic processing section 13 carries out various data processing described later. For example, the process of the first arithmetic processing unit 13 includes a guide guidance process for reading out map data, which will be described later, stored in the data storage unit 15 and guiding the vehicle equipped with the information terminal device 1 or the user. .

The first communication section 14 is typically composed of a mobile communication device represented by a mobile phone. First
The communication unit 14 of the request message RE from the information terminal device 1 to the center station 2 is input from the first arithmetic processing unit 13.
Q is sent to the uplink UL of the communication network 3. The content of the request message REQ includes at least a map data request command and coordinate information for specifying the range of the requested map data. The detailed content will be described later.

The request message REQ transmitted from the information terminal device 1 is transmitted through the uplink UL of the communication network 3
It is received by the center station 2. The center station 2 analyzes the request message REQ, reads the map data stored in the map data storage unit 23, and sequentially transmits the map data to the information terminal device 1 through the downlink DL of the communication network 3.
The details of the processing of the center station 2 will be described later.

In the information terminal device 1, the first communication unit 1
4 is a downlink D from the center station 2 to the communication network 3.
The map data sent to L is received and output to the first arithmetic processing unit 13. The first arithmetic processing unit 13 stores the acquired map data in the data storage unit 15. further,
The first arithmetic processing unit 13 uses the map data stored in the data storage unit 15 to perform various processes such as map display, position detection, route search, and guidance.

The data storage section 15 is typically composed of a rewritable storage medium represented by a hard disk drive or a flash memory.
Map data is stored in the data storage unit 15, and this map data is used for position detection, guidance, and the like. The detailed contents of the map data stored in the data storage unit 15 will be described later.

The first data reading section 18 performs a process of reading necessary map data from the data storage section 15.

The connection information generating unit 17 performs a process of complementing and generating the connection information of the road network with respect to the map data read by the first data reading unit 18. Detailed contents of the connection information complementing and generating process performed by the connection information generating unit 17 will be described later. In the first arithmetic processing unit 13, various data processing such as route search and position detection processing is mainly performed by using the connection information of the road network complemented and generated by the connection information generation unit 17.

The data writing unit 19 writes and stores data in the data storage unit 15 according to an instruction from the first arithmetic processing unit 13, and mainly stores the map acquired from the center station 2 through the first communication unit 14. Data in the data storage unit 1
5 is written.

The first output section 16 is typically composed of a display device and a speaker. On the display device, a map is displayed together with the current position or guidance information is displayed. The speaker provides the guidance information to the user by voice.

Next, the configuration of the center station 2 will be described. The center station 2 includes a second communication unit 21, a second arithmetic processing unit 22, a map data storage unit 23, a second data reading unit 26, a second input unit 24, and a second output unit 25. To be done.

As described above, the request message REQ transmitted from the information terminal device 1 is transmitted to the center station 2 through the uplink UL of the communication network 3. The second communication unit 21 is composed of a communication device represented by a modem, a terminal adapter, or a gateway. Here, the gateway means not only a device or a function for connecting the communication network 3 and the center station 2 that use different communication protocols, but also unauthorized access to the center station 2 via the communication network 3. Means a device or function for preventing such a situation. The second communication unit 21 is connected to the communication network 3 and controls data reception from the information terminal device 1 and data transmission to the information terminal device 1. More specifically, the second communication unit 21 receives, as one of its functions, the request message REQ transmitted through the uplink UL of the communication network 3 and receives the request message REQ.
Output to 2.

The second arithmetic processing section 22 analyzes the input request message REQ. As described above, the request message REQ includes at least the request command of the map data from the information terminal device 1 and the coordinate information for specifying the requested map, and the detailed content thereof will be described later. Further, the second arithmetic processing unit 22 gives the second data reading unit 26 an instruction to read the map data stored in the map data storage unit 23 based on the content of the request message REQ.

The map data storage unit 23 is typically a hard disk drive, CD-ROM drive or D
It is composed of a VD-ROM drive, and comprises at least a storage medium from which the stored map data can be read and its driver.

The second data reading section 26 is instructed by the second arithmetic processing section 22 to operate the map data storage section 2 described above.
The map data stored in No. 3 is read and output to the second arithmetic processing unit 22.

The map data read by the second data reading unit 26 and output to the second arithmetic processing unit 22 is sent to the downlink DL of the communication network 3 via the second communication unit 21. The information is sequentially transmitted to the information terminal device 1.

The second input section 24 is composed of an input device mainly used in a computer system such as a keyboard and a mouse. Using this second input section 24,
Various processing requests are input from an operator who operates and manages the center station 2.

The second output section 25 is typically composed of a display device. The display device mainly displays the contents of road network data stored in the map data storage unit 23.

The overall configuration of the map information providing system and the configurations of the information terminal device 1 and the center station 2 have been described above. The data structure of map data used in the map information providing system will be described below.

[Data Structure of Map Data] The data structure of map data used in the map information providing system is as follows.
Since it is the same as that described in the first embodiment with reference to FIGS. 2 to 4, detailed description thereof will be omitted. In this embodiment, the map data having such a data structure is stored in the map data storage unit 23 of the center station 2, and in response to a request from the information terminal device 1, the information terminal device 1 is sent via the communication network 3. To deliver to. The information terminal device 1 receives the map data distributed from the center station 2, stores it in the data storage unit 15, and reads it out to the main memory for use when necessary.

As described in the first embodiment, the map data used in this embodiment keeps the connection information of the road network to be recorded to the minimum necessary.
The data capacity is smaller than that of conventional map data, and the time and cost required for communication when distributing from the center station 2 to the information terminal device 1 can be reduced. The map data distributed to the information terminal device 1 is temporarily stored in the data storage unit 15 of the information terminal device 1. However, since the data capacity of the map data is small, the map data in the data storage unit 15 is stored in the data storage unit 15. The occupied capacity can be reduced. Furthermore, since the capacity of the data storage unit 15 of the information terminal device 1 can be reduced, the cost of the information terminal device 1 can be reduced.

[Procedure of Processing of Information Terminal Device 1] As described above, the information terminal device 1 is typically a car navigation device or a PDA. As is well known, a vehicle-mounted car navigation device executes map matching, route search, and guidance processing. Each process performed by the information terminal device 1 is performed using the map data having the data structure described in the first embodiment. The procedure of the process of reading the map data by the information terminal device 1 is the same as the process procedure described in the first embodiment by taking the route search process as an example, and thus detailed description thereof will be omitted.

The map information providing system is characterized in that the information terminal device 1 receives and uses the map data distributed from the center station 2 through the communication network 3. The process of transmitting and receiving the map data between the center station 2 and the information terminal device 1 will be described below.

[Map Data Transmission / Reception Processing] In recent years, research and development have been conducted on systems that provide map data from the center station 2 to the information terminal device 1. With such a system, the information terminal device 1 can obtain necessary map data when needed. Therefore, a wide range of map data to be distributed to the information terminal device 1 is prepared in the map data storage unit 23 of the center station 2. In this embodiment, the map data storage unit 23 and the data storage unit 15 store map data having the data structure described with reference to FIGS. 2 to 4 in the first embodiment described above.

FIG. 8 is a flowchart showing a processing procedure in which the information terminal device 1 requests the center station 2 to transmit map data in a required range. 9 is a request message R transmitted from the information terminal device 1 according to the processing procedure of FIG.
It is a figure which shows an example of the data format of EQ. Figure 8
At, the user of the information terminal device 1 uses the data storage unit 1
When it is desired to receive map data from the center station 2 in order to add or update new map data to the map data stored in 5, the first input unit 11 is operated to request / receive map data. To start. Next, the user operates the first input unit 11 according to the menu screen displayed on the display of the first output unit 16,
Enter the required map range. Then, the first input unit 1
In response to the user's input, the No. 1 outputs information indicating the range of the map to the first arithmetic processing unit 13 and specifies it (step S).
201). Here, in inputting the range of the map, the user uses the first input unit 11 to enclose a desired range in a rectangular area on the wide area map displayed on the display, or uses an address index. The user inputs the area by the first input unit 11
There is a way to specify. In addition, the user may specify the current position of the information terminal device 1 or an arbitrary point on the map. In this case, the first input unit 11 outputs and specifies the information indicating the point on the map to the first arithmetic processing unit 13 in response to the user's input.

The first arithmetic processing unit 13 is the same as the first input unit 1
When the information on the range or point output from 1 is input, the information on the range or point is converted into longitude and latitude coordinates. Then, the first arithmetic processing unit 13 uses the information on the longitude and latitude coordinates to request the message RE.
Q is generated (step S202).

FIG. 9A shows an example of the data format of the request message REQ generated by the first arithmetic processing unit 13 when the map range is designated in step S201. In FIG. 9A, the request message REQ includes a map request command and longitude and latitude coordinates that specify the range of the map represented by the map data required by the user. Where the longitude and latitude coordinates are
More specifically, when the user designates the wide area map by enclosing it in a rectangular area, it is composed of the lower left longitude coordinate, the lower left latitude coordinate, the upper right longitude coordinate, and the upper right latitude coordinate.

FIG. 9B shows an example of the data format of the request message REQ generated by the first arithmetic processing unit 13 when the point on the map is designated in step S201. In FIG. 9B, the request message REQ includes a map request command and the longitude and latitude coordinates that specify the point on the map represented by the map data required by the user. Where the longitude and latitude coordinates are
More specifically, when the user specifies the current position of the information terminal device 1 or an arbitrary point on the map, it is composed of the point longitude coordinate and the point latitude coordinate.

Next, the first arithmetic processing unit 13 outputs the generated request message REQ to the first communication unit 14, and the first communication unit 14 sends the input request message REQ to the center station 2. In order to transmit, it is transmitted to the uplink UL (step S203), and the processing by this flow is ended.

Next, the map data transmission processing in the center station 2 will be described. FIG. 10 is a flowchart showing a procedure of map data transmission processing in the center station 2.

In FIG. 10, the request message REQ sent from the information terminal device 1 is received by the second communication unit 21 of the center station 2 via the uplink UL of the communication network 3 (step S301), and The request message REQ is output to the second arithmetic processing unit 22.

Next, the second arithmetic processing section 22 analyzes the request content of the request message REQ transmitted from the information terminal device 1 (step S302). This analysis is performed based on the longitude and latitude coordinates described in the request message REQ. As described in the first embodiment, the map data used in the map information providing system is divided into units. Each unit is configured as unit data, and is managed by a file system to which a unit data name that can uniquely specify the longitude and latitude coordinates corresponding to each unit is assigned. That is, the unit including the longitude and latitude coordinates described in the request message REQ can be uniquely specified by analyzing the unit data name.

Next, the second arithmetic processing section 22 uses the second data reading section 26 to map the map data requested by the information terminal device 1 based on the analysis result of the request message REQ. Search from (step S3
03).

Next, the second arithmetic processing section 22 converts the map data read by the second data reading section 26 in step S303 into a data structure suitable for transmission / reception via the communication network 3. (Step S304), and outputs to the second communication unit 21. Note that the data transmission / reception protocol via the communication network 3 does not have the characteristics peculiar to this embodiment, and thus detailed description thereof is omitted here.

Then, the second communication unit 21 sends the data input from the second arithmetic processing unit 22 to the downlink DL of the communication network 3 (step S305), and ends the process according to the flow.

As described above, steps S301 to S3 are performed.
By the processing of 05, the center station 2 can transmit the map data requested by the information terminal device 1 to the information terminal device 1.

Next, the process of receiving the map data in the information terminal device 1 will be described. Step S30
The above-mentioned data transmitted from the center station 2 at 5 is transmitted to the communication network 3
The data is input to the first communication unit 14 of the information terminal device 1 via the downlink DL. The first communication unit 14 includes the communication network 3
The above data input from the downlink DL is sequentially received and output to the first arithmetic processing unit 13. The first arithmetic processing unit 13 sequentially acquires the data output from the first communication unit 14 and reconstructs it as map data. In addition,
Since the processing when reconstructing the map data in the first arithmetic processing unit 13 after receiving the data transmitted from the downlink DL of the communication network 3 does not have the characteristics peculiar to this embodiment, Detailed description is omitted here. Then, the map data reconstructed as map data by the first arithmetic processing unit 13 is stored in the data storage unit 15 via the data writing unit 19.

The map data stored in the data storage unit 15 is read out again by the first data read-out unit 18 as necessary to display the map, detect the position, search the route,
Also used for processing such as guidance. The process after the map data is read from the data storage unit 15 by the first data reading unit 18 is the same as the process procedure of the information terminal device 1 described in the first embodiment, and the connection information It is used for various data processing after generating and complementing the connection information of the road network using the generation unit 17.

As described above, the map information providing system composed of the center station 2 and the information terminal device 1 is used when the map data is transmitted from the center station 2 to the information terminal device 1 via the communication network 3. Since the connection information of the road network described in the map data is minimized, the communication time required for data transmission can be shortened, and as a result, the communication cost can be reduced. Further, when the map data distributed from the center station 2 as described above is received by the information terminal device 1 and stored in the data storage unit 15 of the information terminal device 1, the road network connection is recorded in the same manner. By storing the map data in which the information is kept to the minimum necessary, it is possible to record a wider range of map data in the data storage unit 15, and further, in the data storage unit 15 for storing the map data. The capacity can be reduced, and as a result, the cost of the information terminal device 1 can be reduced. In addition, when the map data stored in the data storage unit 15 is read out and used for each process such as map display, position detection, route search, and guidance guidance, each function can be efficiently used without damaging each function. It becomes possible to trace the connection relationship of the road network.

The second embodiment is the information terminal device 1
As an example, the description has been made assuming a car navigation device, a PDA, and a mobile phone terminal device. However, by creating a database of map data in the personal computer, the personal computer can display the map,
The present embodiment can be applied to applications such as route search. That is, the technical field of the present invention is
The present invention can be applied not only to a movable terminal device but also to a general-purpose stationary terminal device. In this case, the position detection unit 12 described above may be omitted, and the communication network 3 may be a wired transmission path.

Further, in the present embodiment, the information terminal device 1
Performs two-way communication with the center station 2 via the communication network 3 to notify the center station 2 of the map range or point required by the user, and receives the map data corresponding to the range or point. It was However, the center station 2 may transmit the map data to the information terminal device 1 in a broadcast format.

In the second embodiment, as the data structure of the map data, only the connection information from the links to the nodes is recorded in the map data regarding the connection relationship between the nodes and the links constituting the road network. Then, when the map data is read, the connection information from the link to the node described in the link table is used to generate and use the connection information from the node to the link in the node table. This is because the connection information for tracing the connection from the node to the link generally requires a larger amount of data than the connection information for tracing the connection from the link to the node. Many can be reduced. However, if such an effect is not expected, only the connection information from the node to the link is recorded in the above map data, and when the map data is read out,
The connection information from the link to the node may be generated and used in the link table using the connection information from the node to the link described in the node table.

As described above, according to the present invention, the digital map data stored in the map data storage unit is stored between the nodes and links forming the road network necessary for the position detection processing and the route search processing. Since the connection relation of is omitted and recorded in a recoverable format, the data capacity of the map data can be reduced. As a result, the range of map data that can be stored in the map data storage unit can be widened or the capacity of the map data storage unit can be reduced. In addition, since the connection information generation unit newly generates the connection information that has been omitted, even when performing position detection processing or route search processing using the above map data, the road efficiency can be maintained without sacrificing processing efficiency. The advantageous effect of being able to trace the network connection relationship is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an information terminal device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a data structure of map data used in the information terminal device 1 of FIG.

3 is a diagram showing a data structure of map data used in the information terminal device 1 of FIG.

4 is a diagram showing a data structure of map data used in the information terminal device 1 of FIG.

5 is a flowchart showing a procedure of processing by the connection information generating unit 17 in the map data read by the first data reading unit 18 of FIG.

6 is a diagram showing a data structure of map data generated by a connection information generation unit 17 of FIG.

FIG. 7 is a block diagram showing configurations of an information terminal device and a map information providing system according to a second embodiment of the present invention.

8 is a flowchart showing a processing procedure in which the information terminal device 1 of FIG. 7 requests the center station 2 to transmit map data in a required range.

9 is a diagram showing an example of a data format of a request message REQ transmitted from the information terminal device 1 of FIG.

10 is a flowchart showing a procedure of map data transmission processing in the center station 2 of FIG.

FIG. 11 is a diagram showing an example of a road network represented by map data.

12 is an example of a data structure of conventional road network data expressing the road network shown in FIG.

[Explanation of symbols]

1 ... Information terminal device 11 ... First input section 12 ... Position detector 13 ... First arithmetic processing unit 14 ... First communication unit 15 ... Data storage unit 16 ... First output unit 17 ... Connection information generation unit 18 ... First data reading unit 19 ... Data writing section 2 ... Center station 21 ... Second communication unit 22 ... Second arithmetic processing unit 23 ... Map data storage unit 24 ... Second input section 25 ... Second output section 26 ... Second data reading unit 3 ... communication network DL ... Downlink UL ... Uplink

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI G09B 29/00 G09B 29/00 Z 29/10 29/10 A (56) Reference JP-A-8-128844 (JP, A) JP-A-10-49047 (JP, A) JP-A-9-127865 (JP, A) JP-A-11-51669 (JP, A) JP-A-2002-267462 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) G01C 21/00-21/36 G06F 17/30 G09B 29/00-29/10

Claims (12)

(57) [Claims] 1. An information terminal device for processing map data including node data indicating a road intersection as a node and link data indicating a road as a link, and a map data storage unit for storing the map data, A map data processing unit for processing the map data stored in the map data storage unit, wherein the map data stored in the map data storage unit includes one side of the node and the other side of the map. Only the one-sided connection information indicating the connection relationship viewed is described, the map data processing unit reads the map data necessary for processing from the map data storage unit, and the map data reading unit. Based on the one-sided connection information described in the map data read by
Another side connection information complementing section that newly generates the other side connection information indicating the connection relationship when viewing one side from the other side of the node and the link, and complements the read map data. An information terminal device, comprising: a map data calculation processing unit that performs a predetermined calculation process on the map data supplemented with the other-side connection information. 2. In the map data stored in the map data storage unit, only node connection information indicating a connection relationship of nodes viewed from a link is described as the one-side connection information, and the other-side connection information. The information complementing unit, based on the node connection information described in the map data read by the map data reading unit, uses the link connection information indicating the connection relationship of the links viewed from the node as the other side connection information. The information terminal device according to claim 1, which is newly generated and complements the read map data. 3. In the map data stored in the map data storage unit, only link connection information indicating a connection relationship of links viewed from a node is described as the one-side connection information, and the other-side connection information. The information complementing unit, based on the link connection information described in the map data read by the map data reading unit, node connection information indicating a connection relationship of nodes viewed from a link as the other side connection information. The information terminal device according to claim 1, which is newly generated and complements the read map data. 4. A center station transmits the map data to at least one information terminal device that processes map data including node data indicating a road intersection as a node and link data indicating a road as a link. A map information providing system for providing the center station, wherein the center station stores the map data requested by the information terminal device, the first map data storage section storing the map data. A map data transmitting unit that reads the map data from the unit and transmits the map data to the information terminal device via the transmission path, the information terminal device transmitting the map data from the center station via the transmission path. A map data receiving unit for receiving map data; a second map data storage unit for storing the map data received by the map data receiving unit; A map data processing unit for processing the map data stored in the second map data storage unit, wherein the map data transmitted from the center station includes one of the nodes and the link and the other of the two. Only the one-sided connection information indicating the connection relationship viewed from the side is described, the map data processing unit reads out map data necessary for processing from the second map data storage unit, and Based on the one side connection information described in the map data read by the map data reading unit,
Another side connection information complementing section that newly generates the other side connection information indicating the connection relationship when viewing one side from the other side of the node and the link, and complements the read map data. A map information providing system, comprising: a map data operation processing unit that performs a predetermined operation process on the map data supplemented with the other side connection information. 5. In the map data transmitted from the center station, only the node connection information indicating the connection relationship of nodes viewed from a link is described as the one side connection information, and the other side connection information complement Based on the node connection information described in the map data read by the map data reading unit, a new link connection information indicating a connection relationship of links viewed from the node as the other side connection information. The map information providing system according to claim 4, wherein the map information providing system generates and complements the read map data. 6. In the map data transmitted from the center station, only link connection information indicating a connection relationship of links viewed from a node is described as the one side connection information, and the other side connection information complement Based on the link connection information described in the map data read by the map data reading unit, node connection information indicating a connection relationship of nodes viewed from a link is newly added as the other-side connection information. The map information providing system according to claim 4, wherein the map information providing system generates and complements the read map data. 7. A program for causing a computer to process map data including node data indicating a road intersection as a node and link data indicating a road as a link, the map data storage storing the map data. And a map data processing step of processing the map data stored in the map data storing step, wherein the map data stored in the map data storing step includes a node and a link from one side. Only one side connection information indicating the connection relationship looking at the other side is described, the map data processing step, a map data reading step of reading map data necessary for processing from the map data storing step, and Map data read by the map data reading step Based on the one-sided connection information described in the data, the other-sided connection information indicating the connection relationship in which one side of the node and the link is viewed from the other side is newly generated and read out. A program comprising: another side connection information complementing step for complementing map data; and map data calculation processing step for performing a predetermined calculation process on the map data with the other side connection information complemented. 8. In the map data stored in the map data storage step, only node connection information indicating a connection relationship of nodes viewed from a link is described as the one side connection information, and the other side connection information is described. The information complementing step is based on the node connection information described in the map data read by the map data reading step, link connection information indicating a connection relationship of links viewed from a node is used as the other side connection information. The program according to claim 7, which is newly generated and complements the read map data. 9. In the map data stored in the map data storage step, only link connection information indicating a connection relationship of links viewed from a node is described as the one-side connection information, and the other-side connection information. In the information complementing step, based on the link connection information described in the map data read by the map data reading step, node connection information indicating a connection relationship of nodes viewed from a link is used as the other side connection information. The program according to claim 7, which is newly generated and complements the read map data. 10. The map data including the node data indicating the intersection of the road as a node and the link data indicating the road as a link is provided from the center station via the transmission line, and is executed by a computer that processes the map data. A map data receiving step of receiving the map data transmitted from the center station via the transmission path, and a map data storage storing the map data received in the map data receiving step. And a map data processing step of processing the map data stored in the map data storing step, wherein the map data stored in the map data storing step includes a node and a link from one side. Only one side connection information that describes the connection relationship when looking at the other side is described The map data processing step includes: a map data reading step of reading map data required for processing from the map data storing step; and the one-sided connection described in the map data read by the map data reading step. Based on the information, the other side connection that newly generates the other side connection information indicating the connection relationship when viewing one side from the other side of the node and the link and complements the read map data. A program comprising: an information complementing step; and a map data calculation processing step of performing a predetermined calculation processing on the map data complemented with the other side connection information. 11. In the map data transmitted from the center station, only the node connection information indicating the connection relationship of nodes viewed from a link is described as the one side connection information, and the other side connection information complement In the step, based on the node connection information described in the map data read by the map data reading step, link connection information indicating a connection relationship of links viewed from a node is newly added as the other side connection information. The program according to claim 10, which is generated and complements the read map data. 12. In the map data transmitted from the center station, only the link connection information indicating the connection relationship of links viewed from a node is described as the one side connection information, and the other side connection information complement In the step, based on the link connection information described in the map data read by the map data reading step, node connection information indicating a connection relationship of nodes viewed from a link is newly added as the other side connection information. The program according to claim 10, which is generated and complements the read map data.