JP4778566B2 - Navigation device, navigation method, and navigation program - Google Patents

Description

  The present invention relates to a navigation device.

  A navigation device mounted on a moving body such as a vehicle usually implements various functions using road link data. For example, when searching for a route to the destination, the cost of the road link is obtained based on the width of the road and the road type (highway, national road, narrow street, etc.) included in the road link data (for example, see Patent Document 1). reference). In the map display, the display color and thickness of the road are changed based on the width, the road type, and the like included in the road link data.

  However, if the data such as the width and the road type included in the road link data is inaccurate or undeveloped, the nature of the road cannot be accurately distinguished. For this reason, problems such as being unable to calculate a desirable guide route or displaying an easy-to-understand map may occur.

JP 2004-191309 A

  Examples of problems to be solved by the present invention include the above. An object of the present invention is to provide a navigation device capable of appropriately performing route calculation and map display even if the width or road type in road link data is insufficient or inaccurate.

The invention according to claim 1 is a navigation device , a road name class that is different from a road-related word related to a road size, a road type, and a width and indicates a road size. Based on the road- related terms included in the road name with reference to the storage means , the road link data acquisition means for acquiring the road link data including the road name , road type and width , and the storage means And classifying means for classifying each road link into a plurality of road name classes, and map display means for performing processing for displaying a map including roads according to the plurality of road name classes. .

The invention according to claim 6 is a navigation method executed by a navigation device including a storage unit, wherein the storage unit is different from a road-related word related to a road size, a road type, and a width. A road link data acquisition step for storing a road link data including a road name , a road type, and a width , wherein a correspondence relationship with a road name class that is a class indicating a road size is stored. And a step of classifying each road link into a plurality of road name classes based on road-related words included in the road name with reference to the storage unit , and including roads according to the plurality of road name classes. And a map display step for performing a process of displaying a map .

The invention according to claim 7, a navigation program thus executed in the navigation device comprising a computer, and road-related words relating to the size of the road, and the road type and the road width be different A storage means for storing a correspondence relationship with a road name class that is a class indicating a road size, a road link data acquisition means for acquiring road link data including a road name , a road type, and a width ; Classification means for classifying each road link into a plurality of road name classes based on road-related terms included in the road name, and map display means for performing processing for displaying a map including roads according to the plurality of road name classes The computer is made to function as.

It is a block diagram which shows the structure of the navigation apparatus which concerns on an Example. The structure of the map data used in the Example of this invention is shown typically. The structure of road data is shown. The structure of link data is shown. It is a figure explaining a link and a node. An example of classification of road links based on road names is shown. It is a correspondence table | surface of the classification | category of a road link, and the thickness of the line which shows a road, and a color. It is an example of a map display screen. It is a flowchart of a map display process. It is a correspondence table | surface which shows the relationship between the classification of a road link, and a display scale. It is an example of a map display at the time of a scale change. It is a flowchart of the display process at the time of a scale change. A special display example of the map is shown. It is a table | surface which shows whether the road link of each class is used for route calculation. It is an example of a guidance route. It is a flowchart of a route search process. It is a schematic block diagram of a map data creation device. The data structure example of map data and map data for car navigation is shown. It is a flowchart of a map data creation process. An example of classifying road links based on address information is shown.

10 Independent positioning device 18 GPS receiver 20 System controller 22 CPU
36 Data storage unit 40 Display unit 60 Input device 100 Navigation device

In a preferred embodiment of the present invention, the navigation device includes link data acquisition means for acquiring road link data including a road name, and based on the road name, each road link is divided into a plurality of classes indicating the size of the road. Classification means for classifying, and navigation processing means for executing navigation processing according to the plurality of classes .

The above navigation device is suitable for a car navigation device mounted on a vehicle, for example, and executes navigation processing such as map display using map data. The map data generally includes link data corresponding to roads and node data corresponding to intersections. Said navigation apparatus acquires the road link data containing a road name, and classifies each road link into the some class which shows the magnitude | size of a road based on a road name. For example, each road link is classified into a relatively large road class such as an expressway or a main road, a smaller standard road class, and a small road class such as a narrow street. The navigation processing means executes navigation processing according to the class of each road link. As a result, even if road type and width data are not included in the road data, or even if it is included or incorrect, appropriate navigation processing is executed using the classification result based on the road name. Can do.

In one aspect of the navigation device, the road name includes a road-related word related to a road size, and the classification unit classifies each road link into the plurality of classes based on the road-related word. . In this aspect, for example, each road link is classified into a plurality of classes indicating road sizes based on predetermined road-related words included in road names such as “highway”, “drive”, and “avenue”. Since these road-related words often indicate the size and characteristics of the road, each road link can be appropriately classified by using the road-related words.

In a preferred example, when the navigation processing means performs a process of displaying a map as the navigation process, according to the plurality of classes , the color of the line for displaying each road link on the map display screen and / or Change the thickness.

In another preferable example, when the navigation processing unit performs a process of displaying a map as the navigation process, the scale change is performed according to the plurality of classes when the scale of the map to be displayed is changed. Decide whether to display each road link on a later map.

In still another preferred example, when the navigation processing means performs a route calculation process to the destination as the navigation process, whether to use each road link in the route calculation process according to the plurality of classes . Decide whether or not.

In still another preferred example, when the navigation processing unit performs a process of displaying a map as the navigation process, the navigation processing unit displays a map in a display form corresponding to the road-related word according to the plurality of classes. To display each road link.

In another preferred embodiment of the present invention, the navigation method includes a link data acquisition step of acquiring road link data including a road name, and a plurality of road links indicating a road size based on the road name . A classification process for classifying into classes , and a navigation processing process for executing navigation processing according to the plurality of classes . Also with this method, it is possible to execute an appropriate navigation process for each road link using the classification result based on the road name.

In still another preferred embodiment of the present invention, a navigation program executed in a navigation device including a computer includes link data acquisition means for acquiring road link data including a road name, and each road link based on the road name. The computer is caused to function as a classifying unit that classifies a road into a plurality of classes indicating the size of a road , and a navigation processing unit that executes a navigation process according to the plurality of classes .

  When the computer executes this program, the above navigation device can be realized. The above program can be suitably handled in a state stored in a storage medium.

  In still another preferred embodiment of the present invention, the map data creation device receives original map data including a plurality of road links each having a road name, and classifies each road link into a plurality of classes based on the road name. And a data conversion unit that classifies the plurality of road links into a plurality of layers and creates map data having a hierarchical structure based on a determination result by the class determination unit.

  The map data creation device is configured as a terminal device such as a computer, for example, and acquires original map data including a plurality of road links each having a road name from a map database or the like. Then, the class determining means classifies each road link into a plurality of classes based on the road name. The class can be determined as classes A to C in the order of road sizes, for example. Then, the data conversion means classifies each road link into a plurality of layers based on the class determination result, and creates map data having a hierarchical structure. In the above example, for example, when creating map data having three layers, the highest layer includes A class road links, the intermediate layer includes A and B class road links, and the lowest layer includes All classes of road links A to C can be included. Thus, map data having a hierarchical structure can be created from the original map data having no road type by using the road name.

  In one aspect of the map data creation device, the class determination unit can perform class determination based on a road-related word included in the road name. In this aspect, for example, the class of each road link is determined based on a predetermined road-related word included in a road name such as “highway”, “drive”, and “avenue”. Since these road-related words often indicate the size and characteristics of the road, by using the road-related words, each road link can be appropriately classified and classified into a hierarchical structure.

  In still another embodiment of the present invention, the map data creation method receives original map data including a plurality of road links each having a road name, and classifies each road link into a plurality of classes based on the road name. And a data conversion step of classifying the plurality of road links into a plurality of layers and creating map data having a hierarchical structure based on the determination result by the class determination means. Also by this method, map data having a hierarchical structure can be created from original map data having no road type using road names.

  In still another embodiment of the present invention, a map data creation program executed in a terminal device including a computer receives original map data including a plurality of road links each having a road name, and based on the road name, Class determination means for classifying each road link into a plurality of classes, and classifying the plurality of road links into a plurality of layers based on the determination result by the class determination means, and creating map data having a hierarchical structure The computer is caused to function as data conversion means.

  When the computer executes this program, the above map data creation device can be realized. The above program can be suitably handled in a state stored in a storage medium.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The following description shows an example in which the present invention is applied to a navigation device mounted on a vehicle.

[Navigation device]
FIG. 1 shows a configuration of a navigation device 100 according to an embodiment of the present invention. As shown in FIG. 1, the navigation device 100 includes a self-supporting positioning device 10, a GPS receiver 18, a system controller 20, a disk drive 31, a data storage unit 36, a communication interface 37, a communication device 38, a display unit 40, and an audio output. A unit 50 and an input device 60 are provided.

  The autonomous positioning device 10 includes an acceleration sensor 11, an angular velocity sensor 12, and a distance sensor 13. The acceleration sensor 11 is made of, for example, a piezoelectric element, detects vehicle acceleration, and outputs acceleration data. The angular velocity sensor 12 is composed of, for example, a vibrating gyroscope, detects the angular velocity of the vehicle when the direction of the vehicle is changed, and outputs angular velocity data and relative orientation data. The distance sensor 13 measures a vehicle speed pulse composed of a pulse signal generated with the rotation of the vehicle wheel.

  The GPS receiver 18 receives radio waves 19 carrying downlink data including positioning data from a plurality of GPS satellites. The positioning data is used to detect the absolute position of the vehicle from latitude and longitude information.

  The system controller 20 includes an interface 21, a CPU 22, a ROM 23, and a RAM 24, and controls the entire navigation device 100.

  The interface 21 performs an interface operation with the acceleration sensor 11, the angular velocity sensor 12, the distance sensor 13, and the GPS receiver 18. From these, vehicle speed pulses, acceleration data, relative azimuth data, angular velocity data, GPS positioning data, absolute azimuth data, and the like are input to the system controller 20. The CPU 22 controls the entire system controller 20. The ROM 23 includes a nonvolatile memory (not shown) in which a control program for controlling the system controller 20 is stored. The RAM 24 stores various data such as route data preset by the user via the input device 60 so as to be readable, and provides a working area to the CPU 22.

  A system controller 20, a disk drive 31 such as a CD-ROM drive or a DVD-ROM drive, a data storage unit 36, a communication interface 37, a display unit 40, an audio output unit 50, and an input device 60 are mutually connected via a bus line 30. It is connected to the.

  The disk drive 31 reads and outputs content data such as music data and video data from a disk 33 such as a CD or DVD under the control of the system controller 20. The disk drive 31 may be either a CD-ROM drive or a DVD-ROM drive, or may be a CD and DVD compatible drive.

  The data storage unit 36 is composed of, for example, an HDD and stores various data used for navigation processing such as map data and facility data.

  The communication device 38 includes, for example, an FM tuner, a beacon receiver, a mobile phone, a dedicated communication card, and the like, and traffic congestion and traffic information distributed from a VICS (Vehicle Information Communication System) center via the communication interface 37. Receive road traffic information and other information.

  The display unit 40 displays various display data on a display device such as a display under the control of the system controller 20. Specifically, the system controller 20 reads map data from the data storage unit 36. The display unit 40 displays the map data read from the data storage unit 36 by the system controller 20 on a display screen such as a display. The display unit 40 includes a graphic controller 41 that controls the entire display unit 40 based on control data sent from the CPU 22 via the bus line 30 and a memory such as a VRAM (Video RAM), and can display image information that can be displayed immediately. A buffer memory 42 that temporarily stores data, a display control unit 43 that controls display of a display 44 such as a liquid crystal display or a CRT based on image data output from the graphic controller 41, and a display 44 are provided. The display 44 is composed of, for example, a liquid crystal display device having a diagonal of about 5 to 10 inches, and is mounted near the front panel in the vehicle.

  The audio output unit 50 is a D / A converter that performs D / A conversion of audio digital data sent from the CD-ROM drive 31, DVD-ROM 32, RAM 24, or the like via the bus line 30 under the control of the system controller 20. 51, an amplifier (AMP) 52 that amplifies the audio analog signal output from the D / A converter 51, and a speaker 53 that converts the amplified audio analog signal into sound and outputs the sound into the vehicle. Yes.

  The input device 60 includes keys, switches, buttons, a remote controller, a voice input device, and the like for inputting various commands and data. The input device 60 is disposed around the front panel and the display 44 of the main body of the in-vehicle electronic system mounted in the vehicle. When the display 44 is a touch panel system, the touch panel provided on the display screen of the display 44 also functions as the input device 60.

  The CPU 22 functions as a link data acquisition unit, a classification unit, and a navigation processing unit by executing a program stored in advance in the ROM 23 or the like.

[Map data]
FIG. 2 schematically shows the configuration of map data used in this embodiment. The map data has a hierarchical structure including a plurality of layers corresponding to a plurality of different scales. Although FIG. 2 illustrates the map data of three layers for convenience of explanation, the map data may have a larger number of hierarchical structures. In each layer, one unit of map data is referred to as “block (B)”. Note that “block” is a concept indicating a geographically wide range, and can also be expressed as “parcel”, “mesh”, or the like. In FIG. 2, layer 3 is the highest layer and corresponds to the widest map. Layer 1 is the lowest layer and corresponds to the most detailed map.

  The map data 120 is prepared separately for each layer, and includes map display data 122 and road data 124, respectively. The map display data 122 is data used to display a map image to the user, and mainly includes image data corresponding to the map. The road data 124 is data indicating nodes and road links (also simply referred to as “links”) constituting the road, and is used in map display and route search.

  FIG. 3 shows the structure of road data. The road data 124 includes node data 125 and link data 126. The node corresponds to a predetermined point such as an intersection on the road, and the node data 125 is data indicating the node. On the other hand, the link corresponds to one section of the road divided by an intersection or the like, and the link data 126 is data indicating the link.

  Examples of nodes and links are shown in FIGS. 5 (A) and 5 (B). A map including a plurality of roads 111 shown in FIG. 5A includes a plurality of nodes and links as shown in FIG. In FIG. 5B, each node is indicated by a node ID (N00001 etc.) and each link is indicated by a link ID (L00001 etc.).

  FIG. 4 shows the structure of link data. The link data 126 includes a link ID and a link attribute. “Link ID” is information for identifying each link, and is uniquely assigned to each link. “Link attribute” is information indicating the attribute of the link. Specifically, the link attributes include a road name, road type, width, coordinates, length, and the like. “Road name” is the name of the road to which the link belongs. “Road type” is a classification of the type of road to which each link belongs, and examples include “highway” and “national road”. “Width” is the width of the road corresponding to the link, “Coordinate” is the position coordinate of the start point and end point of the link, and “Length” is the length of the link.

  Here, as shown in FIG. 4, many links included in the link data 126 include road types and widths as in Example 1 and road types and widths as in Example 2. Some are not. Even if the road type and width are included, the information may be inaccurate. In general, a navigation device displays a map or calculates a route based on the road type and width, but if there is no information about the road type or width, or if it is inaccurate, the map is displayed. There is a risk of hindering display and route calculation.

  Therefore, in this embodiment, the properties of each link are classified using road names, and map display and route calculation are performed using the results. FIG. 6 shows an example of link classification based on road names. In FIG. 6, “class” indicates classification. In this example, the A class indicates a relatively large road such as an expressway or a main road, the B class indicates an intermediate road, and the C class indicates a relatively small road. The classification based on the road name is basically performed based on words, expressions, etc. (hereinafter referred to as “road related words”) related to the road included in the road name. In the example of FIG. 6, the road name links including road-related words such as “highway” and “toll road” are classified into the A class. In Europe and the United States, names such as “Drive”, “Avenue” and “Boulevard” are often used for main roads and main roads, and these road-related terms are included. Links are also classified into class A. These names may be abbreviated forms such as “Ave.” and “Blvd.”. Furthermore, depending on the country, a unique name such as the name of a president or a historical person, the date of an independence day, or the like may be a road name on a main road, and a link having such a unique name is also A class. are categorized.

  On the other hand, a road name including road-related words such as “road” and “way” indicating a road having a standard size, and a link having a road name that does not include a road-related word are classified into the B class. The Also, road name links including road-related words such as “Array” and “Path” indicating a relatively small road are classified into the C class.

  Whether or not a road name includes a predetermined road-related word can be determined by a known character string matching process.

  In this way, characteristics such as the size of each link can be relatively accurately identified and classified based on the road name included in the link data, particularly by focusing on the road-related words included in the road name. it can. Therefore, even if the link data does not include the road type or width, or even if they are included but they are inaccurate, the link classification result based on the road name is used to display the map. Navigation processing such as route calculation can be performed with high accuracy.

[Navigation process]
Next, an example of navigation processing using the link classification result based on the road name will be described.

(Normal map display)
First, map display as an example of navigation processing will be described. In the present embodiment, the display of the link in the map display is controlled based on the classification result shown in FIG. Specifically, the color and / or thickness of the line indicating the link on the map display screen is changed according to the class of each link.

  FIG. 7 shows an example of the class of each link obtained by classification based on the road name, and the thickness and color of a line indicating the links belonging to the class. As shown in the figure, the A class link, which is a relatively large road, is displayed with a thick line and / or a red line. B class links, which are standard sized roads, are displayed with standard (medium) thickness lines and / or black lines. In addition, a link of class C, which is a relatively small road, is displayed with a thin line and / or a gray line.

  FIG. 8 shows a map display example according to the example of FIG. Thus, by using the classification result based on the road name, each link can be appropriately distinguished and displayed according to the characteristic.

  FIG. 9 shows a flowchart of normal map display processing. This process is realized by the CPU 22 executing a map display program prepared in advance.

  First, CPU22 classifies each link which exists in a display object area using the road name contained in the link data of map data (step S10). Next, the CPU 22 refers to the correspondence table illustrated in FIG. 7, sets the thickness and / or color of the line indicating each link based on the classification result (step S11), and sets the set thickness and / or color. In step S12, each link is displayed.

  Next, the CPU 22 determines whether or not the display target area has changed (step S13). If the display target area has changed, the process of steps S10 to S12 is repeated for the display target area after the change. Thus, each time the display target area changes, each link is displayed with an appropriate thickness and color line.

(Map display when changing scale)
Next, the map display at the time of a scale change is demonstrated. The scale of the map displayed on the display unit may be changed by user input or by automatic control based on the function of the navigation device. In this case, it is necessary to display an appropriate number of links according to the scale after the change.

  FIG. 10 shows the relationship between the class of each link obtained by classification based on the road name and the display scale of the map. In this example, when the scale of the displayed map is a predetermined wide scale (ie, the scale is small), only the A class link is displayed, and when it is the intermediate scale, the A class and B class links are displayed. When the detailed scale (that is, the scale is large), the links of the A class, the B class, and the C class are displayed.

  FIG. 11 shows an example of a display screen when the map display is changed from the detailed scale to the wide area scale. All links from class A to class C are displayed on the detailed scale, but only links of class A are displayed on the wide scale.

  FIG. 12 shows a flowchart of the display process when changing the scale. This process is also realized by the CPU 22 executing a map display program prepared in advance.

  First, in a state where the map display process shown in FIG. 9 is executed and a map of a predetermined display target area is displayed, the CPU 22 determines whether or not a scale change is necessary (step S20). Note that the case where the scale change is necessary includes a case where the user inputs a scale change instruction and a case where the scale change is automatically required in the function of the navigation device.

  When the scale change is necessary (step S20: Yes), the CPU 22 classifies each road link existing in the display target area by using the road name included in the link data of the map data (step S21). Next, the CPU 22 refers to the correspondence table illustrated in FIG. 10 and selects and displays a road link to be displayed according to the scale after the change (step S22).

(Special display)
Next, the special display will be described. The navigation device has several map display modes such as a so-called bird's-eye view map display and a stereoscopic (3D) display in addition to a normal planar display. In these display modes, classification results based on road names can be used to display road links in a special manner according to the characteristics of the roads.

  FIG. 13 shows an example of stereoscopic (3D) display. In FIG. 13, a road link 172 is an expressway and is displayed as an image of an elevated road. The road link 171 is a road whose road name includes “Avenue”, and a roadside tree is drawn on the road. This is because the road including the name “Avenue” is often a road with roadside trees. In addition, a median strip may be drawn on a highway or a toll road. As described above, depending on the map display mode, it is possible to display the characteristics of the road more visually and easily by using the classification result based on the road name.

(Route search)
Next, route search will be described. The navigation device includes a route search function for searching for a route to a destination set by a user or a destination automatically determined based on another function of the navigation device. In the present embodiment, the route search is performed by adjusting the cost of each road link based on the road name. Note that the cost calculation is a method generally used in route calculation and refers to calculating the total cost associated with links and nodes in advance. The cost value associated with the link and the node is set in advance based on various types of information such as the time required to pass through the link and the node and the number of road lanes. Since cost calculation is a known method, detailed description thereof is omitted.

  FIG. 14A shows an example in which the cost of the road link is adjusted based on the road name. In the example of FIG. 14A, the adjusted cost value is shown for each road-related word included in the road name of each road. In this table, a road link including the road-related word “street” is a standard road (ie, cost value = 100), and the cost of other road links is changed according to the road-related word included in the road link. Yes. In cost calculation, a road link having a smaller cost value is more easily selected in route search. In the example of FIG. 14A, a relatively large road link such as a highway or an avenue has a smaller cost value and is easily selected as a route in cost calculation.

  FIG. 15A shows an example of a guide route calculated without performing the cost adjustment shown in FIG. 14A, and FIG. 15B shows an example of a guide route calculated by performing the cost adjustment. . As shown in FIG. 15A, when the route calculation is performed without performing the cost adjustment based on the road name, a guide route that needs to pass through a very small road is simply calculated although the distance is shortened. On the other hand, if a route search is performed by adjusting the cost based on the road name, a reasonable guide route using a road of a certain size can be obtained as shown in FIG.

  FIG. 16 is a flowchart of route search processing. This processing is also realized by the CPU 22 executing a route search program prepared in advance.

  First, the CPU 22 determines a departure place and a destination based on a user input or the like (step S30). Next, the CPU 22 classifies each link in the route calculation target area using the road name included in the link data (step S31). Next, the CPU 22 refers to the cost adjustment table illustrated in FIG. 14A and outputs a route having the minimum cost as a guide route based on the cost of each road link (step S32).

  Thus, by using the classification result based on the road name, an efficient route search process considering only an appropriate road link can be performed.

(Other examples of route search)
In the above example, the route search is performed by adjusting the cost of each road link based on the road name. Alternatively, a road link used in the route search may be selected based on the road name. In the route search, the route is calculated using only relatively large road links such as main roads and main roads except for the vicinity of the departure point and the destination, and the guidance route is calculated. In this example, whether to use each link for route calculation is determined according to the class of each link obtained by classification based on the road name. This method is particularly effective when the distance between the departure point and the destination is a predetermined distance or more.

  FIG. 14B shows whether or not each link obtained by classification based on the road name is used for route calculation. In this example, A class and B class road links are used for route calculation, and C class road links are not used for route calculation. Even if the road names are used in this way, efficient route search processing considering only appropriate road links is possible.

(Map data creation process)
Next, map data creation processing for car navigation using road names will be described. As mentioned above, some map data does not have a road type for each road link, but if there is a road name for each road link, classify each road link based on the road name, It can be classified into a plurality of layers. Thereby, map data having a hierarchical structure can be created.

  FIG. 17 is a schematic block diagram of the map data creation device. The map data creation device 240 includes a map database (DB) 241 that stores map data that includes road names but does not include road types (hereinafter also referred to as “original map data”), a class determination unit 242, data A conversion unit 243 and a car navigation map DB 244 for storing the finally generated car navigation map data are provided. In practice, the map data creation device 240 can be configured as a terminal device such as a PC that executes a map data creation program described later.

  An example of the data structure of the original map data stored in the map DB 241 is shown in FIG. As shown in the figure, each road link has road name, width, and coordinate information, but does not have a road type. Each road is not classified into a plurality of layers.

  The class determination unit 242 reads the data of each road link from the map DB 241 and determines the class of the road link based on the road name of the road link. The “class” is a classification of each road link according to its size and the like, and for example, the classification shown in FIG. 6 can be used. In this case, the class is determined mainly based on the road-related words included in the road name of each road link.

  The data conversion unit 243 classifies each road link into a plurality of layers based on the class determination result of each road link. For example, it is assumed that road links are classified into three classes shown in FIG. In this case, the road data of the highest layer (layer 3) includes only the A class road link, the road data of the intermediate layer (layer 2) includes the A and B class road links, and the lowest layer (layer The road data of 1) may include the A to C class road links. As another example, for example, when the class determination unit 24 classifies road links into four classes, the road data of the highest layer (layer 3) includes road links of A and B classes, and includes intermediate layers (layers). The road data of 2) may include the A to C class road links, and the road data of the lowest layer (layer 1) may include the A to D class road links. In this way, the data conversion unit 243 generates car navigation map data classified for each layer.

  An example of the data structure of the map data for car navigation is shown in FIG. As illustrated, the map data for car navigation is classified into a plurality of layers. In each layer, a link attribute including a road name, width, and coordinates is defined for each road link.

  FIG. 19 is a flowchart of the map data creation process. This process is realized by the map data creation device 240 shown in FIG. 17 executing a map data creation program prepared in advance.

  First, the class determination unit 242 of the map data creation device 240 reads each road link from the map DB 241 and interprets a road-related word in the road name of the road link (step S40). Then, the class determination unit 242 determines the class of the road link based on the road-related word, and supplies the determination result to the data conversion unit 243.

  The data conversion unit 243 classifies each road link into a plurality of layers based on the determined class, and creates car navigation map data as illustrated in FIG. 18B (step S42).

  As described above, in this embodiment, each road link is classified into a plurality of layers based on the road name of the road link, and car navigation map data converted into a format that can be easily referred to from the car navigation system can be generated. .

In the map display process shown in FIG. 9 and the scale change display process shown in FIG. 11, the road link to be displayed is determined using the road name when performing map display. Thus, when the car navigation map data as illustrated in FIG. 18B is created in advance, it is not necessary to determine whether or not each road link is to be displayed during the map display process.
[Modification]
(Classification by address information)
In the above embodiment, each road link is classified into a plurality of classes based on the road name of the road link. In this respect, in addition to the road name, the road link may be classified into a plurality of classes based on the address information (house number) of the road link.

  In particular, in Europe and the United States, in addition to the road name, address information (house number) is often set for the road link. An example of this is shown in FIG. In this example, some road links have house numbers in addition to road names as link attributes. An example of setting the house number is shown in FIG. As shown in FIG. 20B, the house number indicates the address of a section (building) along the road. In the example of FIG. 20B, the road link L40001 passing through the sections of house numbers 1 to 12 has house number 1-12 as the link attribute, and the road link L40002 passing through the sections of house numbers 13 to 16 is used as the link attribute. House numbers 13-16. On the other hand, as shown in FIG. 20A, there is a road link that does not have a house number as a link attribute.

  Therefore, each road link may be classified into a plurality of classes based on whether or not a house number is set as the link attribute. For example, as illustrated in FIG. 20A, road links for which address information (house number) is set are classified as class A, class B, etc., because they are determined to be more important. Road links that are not set can be classified into class C.

(Other variations)
In the above-described embodiment, each link is classified based on the road name regardless of whether road type or width data is present in the link data, and navigation such as map display and route calculation is performed using the classification result. Processing is being executed. Instead, if the link type contains road type and width data, give priority to it, and only link that does not contain road type or width data should be classified by road name as described above. It is good. In that case, it is desirable to match the classification (class) based on the road name with the classification of the existing road type. For example, when the existing road type is classified into four classes of “highway / toll road”, “national road”, “non-national road”, and “narrow street”, there is no road type or width. The links may be classified into any of these four classes based on the road name. As a result, it is possible to classify the links having the road type and the width and the links not having the same according to the same standard, and execute various navigation processes.

  In the above example, an example in which a predetermined road-related word in a road name is detected by matching character strings is shown. Instead, typical road-related words such as “street” and “avenue” may be coded in advance, and road name data may be configured in a format of “unique name + code”. In that case, classification based on the road name is possible by detecting each code from the road name data.

  In addition, since the relationship and regularity between road names and their characteristics differ depending on the country or region, it is preferable to perform classification based on road names according to different standards depending on the country or region.

  The usefulness of class classification based on road names is not limited to the case of using data with insufficient information necessary for class classification such as width and road type. Even data that can be color-coded by an appropriate class may be switched to a color-coded display by road name, for example, by setting. By making the avenue red, the street gray, etc., you can make it easier to find a specific road on the map.

  The present invention can be used for a mobile navigation apparatus represented by a vehicle or the like.

Claims (8)

A storage means for storing a correspondence relationship between a road-related word related to a road size and a road name class that is different from a road type and a width and indicates a road size;
And road link data acquisition means for acquiring road link data including road names, road type and width,
Referring to the storage means, and classifying means for classifying each road link into a plurality of road name classes based on road-related words included in the road name ;
A navigation device comprising map display means for performing a process of displaying a map including a road according to the plurality of road name classes. The map display means changes a color and / or thickness of a line for displaying each road link on the map display screen according to the plurality of road name classes when performing the process of displaying the map. The navigation device according to claim 1 . When changing the scale of the map to be displayed when the map display means is performing the process of displaying the map, each road link is added to the map after the scale change according to the plurality of road name classes. the navigation device according to claim 1 or 2, characterized in that determining whether to display. Provide route calculation means to calculate the route to the destination,
The said route calculation means determines whether each road link is considered in the said route calculation process according to the said several road name class, The said any one of Claims 1-3 characterized by the above-mentioned. Navigation device. The map display means displays each link on the map display screen in a display form corresponding to the road-related word according to the plurality of road name classes when performing the process of displaying the map. The navigation device according to claim 1 . A navigation method executed by a navigation device including a storage unit,
The storage unit stores a correspondence relationship between a road-related word related to a road size, and a road name class that is different from a road type and a width and indicates a road size,
The navigation method includes:
And road link data obtaining step of obtaining road link data including road names, road type and width,
A classification step of classifying each road link into a plurality of road name classes based on road-related words included in the road name with reference to the storage unit ;
And a map display step of performing a process of displaying a map including a road according to the plurality of road name classes. A navigation program thus executed in the navigation device comprising a computer,
Storage means for storing a correspondence relationship between a road-related word related to a road size and a road name class which is a class different from the road type and the width and indicating a road size;
Road name, road link data acquisition means for acquiring road link data including road type and width,
Classification means for classifying each road link into a plurality of road name classes based on road-related terms included in the road name with reference to the storage means,
Map display means for performing a process of displaying a map including a road according to the plurality of road name classes;
A navigation program for causing the computer to function as: A storage medium storing the navigation program according to claim 7 .

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