JP4841126B2 - Navigation device and map display method - Google Patents

Description

  The present invention relates to a technique for presenting map information in a navigation device that is mounted on a vehicle and guides a user's travel.

  As a technology for guiding a user's travel in a navigation device mounted on an automobile, a range including a current location by setting a recommended route between a user and receiving a destination setting from the user is conventionally known. A technique for displaying a recommended route graphic representing a set recommended route on a map together with a mark indicating the current position is widely used.

Further, as a technology related to map display in such a navigation device, when the scale of map display is small, a map including a figure representing a road or a figure representing the shape of a building such as a building is displayed, and the map display scale is reduced. When is large, a technique for displaying a map in which a figure representing a road is drawn on a topographic photograph by a satellite photograph is known (for example, Patent Document 1).
JP 2000-283784 A

In a city and a rural area such as a mountainous area, a map display with the same expression form cannot always provide a map display excellent in convenience and aesthetics for the user.
For example, according to the technique of Patent Document 1, when using a satellite photograph taken at night to express the night on a map when traveling at night, the city area is filled with city lights, so the entire area of the photograph is filled with light. The result is a pure white map display, which in turn lacks visibility and realism. On the other hand, in the countryside such as in a mountainous area, there are few lights in the city, so the map display is almost dark and lonely.

According to the technique of Patent Document 1, in order to perform realistic display using satellite photographs even at a large scale, satellite photographs having a huge amount of data must be stored in the navigation device in advance. There is also a problem.
Therefore, an object of the present invention is to display a map in an expression form suitable for the characteristics of each of an urban area and a rural area.

  In order to achieve the above object, the present invention becomes a display object based on map data including data on the shape and display position of a building figure used for representing a building on a map in a navigation device that displays a map. A map drawing unit that draws a map of a range, a display unit that displays a map drawn by the map drawing unit, and a predetermined range including at least a part of the range of the map to be displayed based on the map data Determining means for determining whether the number or density of the building figure having a display position in the area or the ratio of the area or the area to the area is equal to or higher than a predetermined level, and in the map drawing means, Before the determination means determines that the level is higher than the predetermined level and when it is determined that the level is not higher than the predetermined level, a map expressed in different expression forms is generated in advance. Based on the map data, it is obtained so as to draw a map of the range of a display target.

More specifically, for example, in the map drawing unit, the map having a different color scheme is generated when the determination unit determines that the level is equal to or higher than the predetermined level and when it is determined that the level is not higher than the predetermined level. Try to draw a map.
Alternatively, in the map drawing unit, when the determination unit determines that the level is equal to or higher than the predetermined level, a map including an altitude expression in the mountain range is generated. The map may be drawn so that a map that does not include the expression of altitude is generated.

  Alternatively, when the map drawing means draws a map for nighttime, when at least a part of the building figure is drawn in a high-luminance color and the determination means determines that it is not equal to or higher than the predetermined level. The building graphic is such that a portion drawn in the high luminance color of the building graphic is larger than a portion drawn in the high luminance color of the building graphic when the determination unit determines that the level is higher than a predetermined level. You may make it perform drawing. That is, for example, when drawing the map for nighttime, when the determining means determines that the level is not higher than the predetermined level, the building figure is drawn with a high-luminance color and it is determined that the level is higher than the predetermined level. In addition, the map may be generated by drawing only a part of the building figure with a high luminance color.

  In addition, in such a navigation device, the determination unit has a display position in an area corresponding to the administrative boundary for each administrative boundary included in the range of the map to be displayed based on map data. Determining whether the number or density of building figures or the ratio of area or area to the area is equal to or higher than a predetermined level, and in the map drawing means, a portion corresponding to each administrative boundary of the map to be displayed Of the map corresponding to each administrative boundary so that it is expressed in different expression forms when the determination means determines that it is above the predetermined level for the administrative boundary and when it is determined not to be higher than the predetermined level. The portion may be drawn.

  According to such a navigation apparatus, in order to represent a building such as a building or a house in the map included in the map data, it indicates whether the region corresponding to the displayed map is a region corresponding to a city (city area) or a region corresponding to the countryside. Can be determined from the number, density, area, and area ratio of the building figures. Further, according to such a determination result, the map expression can be switched to an expression according to the characteristics of each region.

More specifically, by changing the color scheme of the map expression or changing the altitude of the mountainous area, the expression that gives an appropriate impression to each of the areas corresponding to the countryside and the areas corresponding to the city The map can be displayed. In addition, when displaying building lights for nighttime with high-luminance color to express the light of the building, the size of the portion displayed in high-luminance color of each building graphic in the area corresponding to the city and the area corresponding to the countryside By reducing the size of the part in the area corresponding to the city, the map is filled with city lights in the area corresponding to the city, resulting in a pure white map display. In addition, the area corresponding to the countryside can be prevented from being displayed as a lonely map because there are few city lights.
In addition, if such a map representation method is changed for each administrative boundary, it is possible to switch to an expression corresponding to the regional characteristics for each administrative boundary.

  Alternatively, in such a navigation device, in the map drawing unit, when the determination unit determines that the level is equal to or higher than the predetermined level, the topography is a two-dimensional shape only in the longitude and latitude direction based on the map data. When the 2D terrain representation map, which is a map having a map, is viewed from the viewpoint above the 2D terrain representation map, an image obtained by the display means is rendered as a map to be displayed, and the determination means is not higher than the predetermined level. Is obtained when a 3D terrain representation map, which is a map having a three-dimensional shape in the longitude and latitude elevation direction, is observed from the viewpoint above the 3D terrain representation map, based on the map data. The displayed image may be drawn as a map displayed by the display means.

  In this way, in areas with few buildings, it is possible to display a realistic map that reflects the three-dimensional shape of the terrain, and to display the three-dimensional shape of the terrain together with the display on the map of the building. It is possible to eliminate the complication of the map and the deterioration of visibility that occur in an area with many buildings, which occurs when reflection is performed.

Further, in this case, the two-dimensional terrain representation map includes a three-dimensional figure representing a building arranged on the terrain having the two-dimensional shape, and the three-dimensional terrain representation map includes the building It is good not to include the figure of the three-dimensional shape showing.
In this way, because there are many buildings, it is difficult to identify the building that will be the landmark of the course and current position, and the map display that enhances the building distinguishability by representing the building realistically as a three-dimensional shape Will be able to do. On the other hand, in areas where the number of buildings where such identification problems are unlikely to occur is small, it is possible to reduce the complexity of map display and map display by not displaying such 3D shapes of buildings. Therefore, the amount of processing can be reduced.

Still further, in the map drawing unit, the observation from the viewpoint when the determination unit determines that the level is equal to or higher than the predetermined level and when the determination unit determines that the level is not higher than the predetermined level. The elevation angle in the direction of the line of sight may be varied.
By doing so, for example, when the map is displayed reflecting the three-dimensional shape of the terrain by setting the elevation angle larger when it is determined that the determination means does not exceed the predetermined level, The terrain in the back can be prevented from being hidden from the viewpoint by nearby hills and the like, and it is possible to perform map expression that is deep and has excellent visibility. On the other hand, when the map display reflecting the three-dimensional shape of the terrain is not performed, the map display expressed using the line of sight closer to the user's line of sight can be performed.

  In addition, in the above navigation apparatus, it is preferable to provide a suppression unit that suppresses frequent changes in the determination result of the determination unit in order to prevent the map expression from being frequently switched.

  As described above, according to the present invention, it is possible to display a map in an expression form suitable for the characteristics of each of an urban area and a rural area.

Hereinafter, embodiments of the present invention will be described.
First, the first embodiment will be described.
FIG. 1 shows the configuration of the navigation apparatus according to the first embodiment.
As shown in the figure, the navigation device includes a control device 1, a recording medium drive 2 for accessing a recording medium 21 such as a DVD-ROM or hard disk storing map data, a GPS receiver 3, an angular acceleration sensor, or a vehicle speed sensor. A travel state sensor 4 that detects the travel state of the vehicle such as a mileage meter, a remote controller 5 (remote controller) that receives input from the user, and a display device 6.

  The control device 1 also includes a map data buffer 101, a map data read processing unit 102, a current state calculation unit 103, a route search unit 104, a navigation image generation unit 105, a memory 106, a main control unit 107, and a GUI control unit 108. ing. Here, a dotted line 121 inside the control device 1 in FIG. 1 indicates an access path of each part to map data stored in the map data buffer 101, and a thick line 122 indicates a path of control information between each part and each part of various data. A thin line connected to the GUI control unit 108 indicates a route of operation information and image information input / output with the user using the remote controller 5 or the display device 6.

  However, the control device 1 described above may be a CPU circuit having a general configuration including peripheral devices such as a microprocessor, a memory, and other graphic processors and geometric processors in terms of hardware. In this case, each unit of the control device 1 described above may be realized as a process embodied by a microprocessor executing a program prepared in advance. In this case, such a program may be provided to the control device 1 via the recording medium 21 or an appropriate communication path.

Next, the structure of the map data stored in the recording medium 21 is shown.
Here, the map data is managed in units called leaflets for each predetermined geographical area, and each leaf is composed of a plurality of levels according to the degree of detail of the map. Each level map of each leaf consists of one or more units, and each unit corresponds to the geographical area of the leaf to which it belongs or a divided area, and maps the corresponding area. , Expressed at the level to which it belongs.

As shown in FIG. 2, the map data includes management data that describes the relationship between each unit and the leaf, corresponding area and level, production date and time of the map data, basic map data representing the map, route data, Consists of color palette data.
Here, the basic map data includes the unit data for each unit described above, and unit management data describing the relationship between each unit data and the leaf, corresponding area, and level. Each unit data includes a road unit representing a road network in the unit, a drawing unit for defining a display map in the unit, and contour line data.

The contour line data indicates contour line information in the area corresponding to the unit.
The road unit is data representing a road network, and includes a node list, a link table, and connection data describing connection and correspondence of nodes and links with other units.
Here, in the road unit, the road is expressed as a set of links that are straight lines, and the end point of each link is a node. The node list is data indicating the coordinates of each node, node attributes such as whether the node corresponds to an intersection, and the like. In addition, the link table indicates the identification of nodes at both ends of each link, the distance and direction of each link, the link cost that is the cost for route search given to each link, the route number of the route to which the link belongs, etc. It is data.

  Next, the drawing unit is a map display element, such as an area graphic representing the shape of a geographical area such as a mountainous area or a river, a road graphic representing a road shape, or a building graphic representing a shape of a building or a house. A background unit representing information about each figure, a character string unit representing information about character information to be displayed on a map such as a building name, a road name, and an intersection name, and the presence of a building such as a gas station on the map Therefore, an icon unit that represents information about an icon that is a mark to be displayed is included.

  The background unit has a graphic record provided for each graphic serving as a geographical display element. Each graphic record includes a graphic object number that is an identifier of the graphic, a river area graphic of the graphic object, and a road graphic. A graphic object type that represents a type such as a building graphic, graphic shape data that is graphic shape data, a graphic display position that represents the position on the map where the graphic is displayed, and a display color that specifies the color used to draw the graphic by color number Includes numbers.

The route data included in the map data has route records provided for each road, and each route record includes a route number that is an identifier of a road, an expressway of each road, a national road, a prefectural road, etc. The route type and the road name of each road are described.
The color pallet data included in the map data has a plurality of color pallets, and each color pallet is described with a pallet number serving as an identifier of the color pallet. In each color palette, the correspondence between the color number and the actual color value (RGB value) associated with the color number is described for each color number that can be used in the graphic record described above.

Here, in this embodiment, four color pallets are provided as a color pallet, a daytime urban color pallet, a daytime countryside color pallet, a nighttime urban color pallet, and a nighttime countryside color pallet.
In such a configuration, the current state calculation unit 103 of the control device 1 repeatedly performs the following processing.
That is, the current state calculation unit 103 matches the current position estimated from the output of the traveling state sensor 4 or the GPS receiver 3 with the map around the current position previously determined read from the map data buffer 101. Processing, etc., the most probable coordinates as the current position, the most probable direction as the current traveling direction, and the most probable link as the current traveling link, the current position, current traveling direction, and traveling The link is determined and set in the memory 106.

  The main control unit 107 receives a destination setting from the user via the remote controller 5 and the GUI control unit 108 in response to a user destination setting request, and sets the destination setting in the memory 106. Further, the main control unit 107 causes the route search unit 104 to search for a recommended route to the destination. The route search unit 104 reads the road data of the road unit in the necessary geographical area from the map data buffer 101, and the route of the lowest cost that first follows the traveling link from the current position set in the memory 106 to the destination. Is calculated as a recommended route based on a predetermined cost model using the link cost of the link record and the route data of the calculated recommended route is set in the memory 106.

In addition, the main control unit 107 determines that the destination has arrived when the current position set in the memory 106 is close to the destination, and clears the destination set in the memory 106 and the recommended route. Do.
Then, the main control unit 107 calculates the geographical area where the map is to be displayed according to the current position and current traveling direction set in the memory 106 and the display scale of the current map set by a user operation or the like. As a map display area, the process of instructing the navigation image generation unit 105 to generate a navigation image for the map display area is repeated. Moreover, the process which changes the said map display area according to a user's scroll operation etc. is also performed.

  Then, the navigation image generation unit 105 instructed to generate the navigation image has the current position set in the memory 106 on the map image generated by the map drawing process performed based on the map data read from the map data buffer 101. In addition, a navigation image representing a recommended route or a destination is generated and displayed on the display device 6 via the GUI control unit 108 is repeated.

Hereinafter, the map image drawing process performed by the navigation image generation unit 105 will be described.
FIG. 3 shows the map drawing process.
As shown in the figure, in this process, first, whether the current time is daytime or nighttime, the time indicated by the clock provided in the navigation device, the lighting state of a lighting device such as a vehicle headlamp or a vehicle width light, etc. The determination is made according to (step 302).
Next, the number of building figures in the determination area is acquired with reference to the background unit (step 304). Here, the determination area may be a map display area, or an area of a predetermined size to which the map display area belongs (area corresponding to a leaf or unit data). The number of building figures is obtained as the number of figure records whose figure object type is a building figure and whose figure display position is within the determination area. In addition, a building figure is a figure which represents a building, a house, a factory, etc. on a map as mentioned above.

  Then, it is determined whether the area corresponding to the map display area is an urban area or a rural area from the number of building figures obtained (step 306). In other words, if the number of building figures obtained or the density of building figures in the judgment area is larger than a predetermined threshold, the area where the map is displayed is set as an urban area. Judge as a region. However, if the sum of the area of the calculated figure and the ratio of the sum of the area to the area of the judgment area is larger than the predetermined threshold, the area where the map is displayed is set as the urban area. The area where the map is displayed may be determined as the countryside area.

  Then, one color palette is set as a use color palette according to the combination of daytime / nighttime determined in step 302 and the urban area / countryside area determined in step 306 (step 308). In other words, if it is determined to be a daytime and urban area, the color palette for daytime urban use is set as a color palette, and if it is determined to be night and an urban area, it is set as a color palette for nighttime using an urban color palette. If it is determined that it is daytime and a rural area, the color palette for daytime countryside is set as a color palette, and if it is determined as a nighttime and rural area, it is set as a color palette that uses a nighttime countryside color palette. To do.

If it is determined in step 306 that it is an urban area, no contour line drawing is set, and if it is determined in step 306 that it is a rural area, contour line drawing is set (step 310). This drawing using contour lines will be described later.
Next, it is checked whether or not it is determined at night in step 302 (step 312). If it is determined that it is daytime, the process proceeds to step 316. If it is determined that it is night, the process proceeds to step 314. In step 314, if the urban area is determined in step 306, the light spot thinning drawing form is set as the light spot drawing form, and if the rural area is determined in step 306, the light spot drawing form is set as the light spot drawing form. Sets the normal drawing form. Here, this light spot drawing form will also be described later.

  In step 316, a graphic record having a graphic display position in the map display area is extracted, and a graphic indicated by each extracted graphic record is drawn. Here, in the drawing of the figure, the color value described in the color palette set as the used color palette is used as the color value indicated by the display color number of the figure record. . If it is determined in step 302 that it is nighttime, for the building figure, the light spot representing the building is drawn as the building figure in the light spot drawing form set in step 314. For a figure whose graphic object type is a mountain figure, that is, a figure representing a mountain, if the use of contour line drawing is set in step 310, drawing based on the display color number and contour line data is performed. If no contour line use drawing is set in 310, drawing based on the contour line data is not performed, and only drawing based on the display color number is performed.

  Next, an icon having a display position in the map display area is extracted based on the icon unit, and each extracted icon is drawn (step 318). Further, based on the character string unit, a character string having a display position in the map display area is extracted, each extracted character string is drawn (step 320), and a map image is completed.

Then, the processing returns to step 302.
Here, the light spot drawing mode described above will be described.
If the figure shape indicated by the figure shape data of the building figure in which the building figure is set as the figure object type in the figure record is the one shown in FIG. 4a, the figure outline and the inside of the figure are shown in FIG. 4b. Is drawn as a high luminance color in the normal light spot drawing mode. On the other hand, the light spot thinning drawing form is a form in which the building diagram is drawn so that the high-intensity part of the figure is reduced as compared with the light spot normal drawing form. As the light spot thinning drawing form, for example, as shown in FIG. 4c, a drawing form in which the figure outline is a high-intensity color and the inside of the figure is partially in a high-intensity color, or a figure outline as shown in FIG. 4d is used. It is possible to use a drawing form in which only the high luminance color is used and the inside of the figure is a low luminance color. Alternatively, as the light spot thinning drawing form, for example, a drawing form in which high luminance color points are arranged at only the vertices of the shape shown in FIG. 4e1 and the others are low luminance colors, as shown in FIG. As shown in FIG. 4B, a drawing form in which a high-luminance color point is arranged at only one point inside the figure such as the figure center of gravity and the others are low-luminance colors as shown in FIG.

Now, FIG. 5 shows an example of a navigation image displayed in the present embodiment.
FIG. 5a shows an example in which the determination in step 302 is daytime and the determination in step 306 is a rural area.
As shown in the figure, in this example, the current position mark 502 indicating the current position set in the memory 106 and the recommended route set in the memory 106 on the map image 501 generated by the above map image generation processing. A recommended route graphic 503 representing the above is drawn. In addition, the map figure is drawn with the character string 504 indicated by the character string unit and the icon 505 indicated by the icon unit as the background indicated by the graphic indicated by the background unit. In this background, each area figure or building figure is drawn in a color set according to the daytime country color palette. Note that the color set assigned to each color number in the daytime countryside color palette is, for example, a warm color set. That is, for convenience, the navigation image and the map image are shown in gray scale in the figure, but the map image is actually displayed in color.

  Further, in the map image in this case, the figure 510 whose graphic object type representing the mountain part in the background is a mountain figure is set to use contour line drawing, so drawing based on the display color number and the contour line data is set. Has been done. In other words, for each altitude range indicated by the contour line data, the interior of the mountainous area is divided into a plurality of areas, and each divided area corresponds to the brightness of the color indicated by the display color number and the daytime countryside color palette. The color is changed according to the altitude range.

FIG. 5b shows an example of the same area as FIG. 5a when the determination in step 302 is daytime and the determination in step 306 is an urban area.
The figure is shown in grayscale for convenience, but in this case, the background of the figure indicated by the background unit is actually drawn as each area figure or building figure in a color set according to the daytime urban color palette. It has become a thing. Here, the color set assigned to each color number in the daytime urban color palette is, for example, a cold color set.

In this case, the graphic object 511 whose graphic object type is a mountain graphic is drawn in a single color based on the display color number because no contour line drawing is set.
Next, FIG. 5c is an example in the case where the determination in step 302 is nighttime and the determination in step 306 is a rural area in the same area as FIG. 5a.
As shown in the figure, in this case, the background by the graphic indicated by the background unit is a graphic in which each area graphic is drawn with a color set according to the night country color palette. In addition, in the map image in this case, the graphic object type 520 representing the mountain area in the background is the mountain area graphic, and the drawing using the contour line is set, so that the drawing based on the display color number and the contour line data is set. Has been done.

And, for the building figure whose figure object type is a building, the light spot normal drawing form is set as the light spot drawing form, so that the figure outline and the inside of the figure are filled with a high luminance color as shown in FIG. It is drawn as an image.
Next, FIG. 5d is an example in the case where the determination in step 302 is night and the determination in step 306 is an urban area for the same area as FIG. 5a.
In this case, the background by the graphic indicated by the background unit is actually a graphic of each area drawn in a color set according to the nighttime color palette. In this case, the graphic 521 whose graphic object type is a mountain graphic is drawn with a single color based on the display color number because no contour line use drawing is set.

  And since the building figure whose figure object type is a building is set to the light spot thinning drawing form as the light spot drawing form, as shown in any of FIGS. 4c, d, e1, and f1, While the color portion is included, the image is drawn as an image having a smaller area of the high luminance color portion than in the case where the light spot normal drawing mode is set as the light spot drawing mode.

Therefore, as understood from a comparison between FIG. 5c and FIG. 5d, when it is determined that it is an urban area at night, the light spot area representing the building figure is smaller than when it is determined that it is a rural area. The
The embodiment of the present invention has been described above.
By the way, in the above embodiment, for the entire map image, the same setting of the color palette used, the same contour line usage drawing presence / absence, and the same light spot drawing mode setting are used. For example, the area corresponding to the image is divided into a plurality of areas for each administrative boundary such as a city and a town, and determination of the country / city area is performed for each divided area, and each divided according to the determination result The drawing may be performed by setting the use color palette, the contour line use drawing, and the light spot drawing form for each region. In addition, when the area | region corresponding to the map image to produce | generate is divided | segmented for every administrative boundary, in order to identify the area | region corresponding to each administrative boundary, the information which shows the area | region of administrative boundaries, such as a city and a town, beforehand in map data. Try to include it.

  As described above, according to the present embodiment, whether the area corresponding to the displayed map image is an urban area or a rural area is determined based on the number of building figures representing buildings such as buildings and houses on the map included in the map data. Can do. Further, the map expression can be switched to an expression according to the characteristics of each area according to the distinction between the urban area and the country area thus determined. More specifically, by changing the color scheme of the map expression or changing the expression of the mountainous area, the map image is displayed with an expression that gives an impression appropriate for each of the rural area and the urban area. Can do. In addition, when building shapes representing buildings such as buildings and houses are displayed in high-luminance colors at night to represent city lights, the size of the portion displayed in the high-luminance color of each building graphic in urban areas is In urban areas, it is possible to prevent the area from being filled with city lights and resulting in a white map display. Since there are few lights, it can prevent becoming a lonely map display.

Hereinafter, a second embodiment of the present invention will be described.
The second embodiment relates to a case where the navigation apparatus shown in the first embodiment above further displays a navigation image using a map image by three-dimensional representation.
FIG. 6 shows a configuration of map data stored in the recording medium 21 in the second embodiment.
As shown in the figure, the map data according to the present embodiment is the map data according to the first embodiment shown in FIG. 2, and in addition to adding three-dimensional terrain data to each unit data, 3D graphic data for representing the shape of a building as a 3D graphic is added to a part or all of a graphic record whose graphic object type is a building graphic. As shown in the figure, the 3D graphic data includes 3D shape data representing the shape of the 3D graphic of the building, and 3D graphic display reference coordinates representing the position on the map where the 3D graphic is displayed.

  Here, the three-dimensional data included in the unit data is a terrain map represented by longitude and latitude elevation, and the data format of such a three-dimensional terrain map is DEM (Digital Elevation Model) or TIN (Triangulated Irregular Network). Are widely used.

Next, an operation when displaying a navigation image using a map image by three-dimensional representation in the second embodiment will be described.
When the three-dimensional display of the navigation image is set by a user operation or the like, the following operation is performed.
That is, the main control unit 107 obtains a map display reference position and a map display direction according to the current position and current traveling direction set in the memory 106, a predetermined map operation of the user, and the like, and sets these by a user operation or the like. The navigation map generation unit 105 is notified together with the current map display scale and the process of instructing generation of the navigation image is repeated.

  The navigation image generation unit 105 instructed to generate the navigation image is set in the memory 106 on the map image generated by the three-dimensional map drawing process performed based on the map data read from the map data buffer 101. A process of generating a navigation image representing the current position, recommended route, and destination and displaying the navigation image on the display device 6 via the GUI control unit 108 is repeated.

FIG. 7 shows the procedure of the 3D map drawing process performed by the navigation image generation unit 105.
As shown in the figure, in this process, first, the travel distance counter is reset (step 702). Here, the travel distance counter is a counter that refers to the output of the travel state sensor 4 and counts the travel distance after reset.
Next, the number of building figures in the determination area is acquired (step 704), and the urban / country area is determined (step 706). Here, the number of building figures is obtained as the number of figure records whose figure object type is a building figure and whose figure display position is within the determination area. In the second embodiment, the determination area is a geographical range corresponding to the unit to which the current position belongs. In addition, the size of the geographical range corresponding to each unit is the same (for example, 1 km × 1 km). If the obtained number of building figures is larger than a predetermined threshold (for example, 50), the area where the map is displayed is determined as an urban area, and if it is small, the area where the currently running map is displayed is determined as a country area. To do. However, the determination of the urban area and the rural area may be performed in the same manner as in the first embodiment.

Next, in step 706, according to the determination result, the viewpoint position, the line-of-sight direction, and the viewing angle for generating a three-dimensional representation map, the map display reference position and the map display orientation notified from the main control unit 107, and It is determined based on the map display scale (step 708).
Here, a method of generating a three-dimensional representation map will be described.
As shown in FIG. 8a, the three-dimensional representation map is generated as a map image obtained when the map is observed with a certain viewing angle in the visual line direction 801 from the position of the viewpoint 800 set above the map. As shown in FIG. 8c1, the direction in which the line-of-sight direction 801 is projected on the map coincides with the map display direction 802 such as the vehicle traveling direction, and the map image is within the field of view when observed as described above. As shown in FIG. 8b, the map 810 to be entered is obtained as a map 811 obtained by coordinate conversion so that the map 810 is reduced and displayed as it is farther from the viewpoint. The viewing angle is the viewing angle θ1 corresponding to the vertical direction of the map 811 after the coordinate conversion so that the map 811 after the coordinate conversion becomes a rectangular map having a predetermined vertical and horizontal size as shown in FIGS. 8c1 and c2. And a viewing angle θ2 corresponding to the horizontal direction of the map 811 after coordinate conversion. The position of the viewpoint 800, the line-of-sight direction 801, and the viewing angles θ1 and θ2 are the map display reference position such as the current position indicated by X in each figure of FIG. It is determined to be located at a predetermined position in the center in the left-right direction. Further, the position of the viewpoint 800, the line-of-sight direction 801, and the viewing angles θ1 and θ2 are determined so that the scale around the map display reference position is substantially the map display scale in the map 811 after coordinate conversion.

  In the present embodiment, when it is determined that the area is an urban area in step 706, the elevation angle in the line-of-sight direction 801 is θa as shown in FIG. 8d1, and when it is determined that the area is a country area in step 706, As shown in FIG. 2, the elevation angle in the line-of-sight direction is θb. However, θa <θb. Here, for example, θa is 3 degrees and θb is 5 degrees.

Then, on the premise of the elevation angle of the line-of-sight direction 801 thus determined, the viewpoint position 800, the line-of-sight direction 801, and the viewing angles θ1 and θ2 are determined so as to satisfy the above conditions.
Now, returning to FIG. 7, when the viewpoint position, the line-of-sight direction, and the viewing angle are determined in this way, the map of the three-dimensional representation corresponding to the determination result of the country / city area is drawn.
Here, when it is determined that the area is an urban area (step 710), a three-dimensional representation map is drawn in consideration of the three-dimensional shape of the building figure without considering the three-dimensional landform (step 712).
That is, the drawing of the map of the three-dimensional representation of this urban area is performed on the two-dimensional map formed by the graphic indicated by each graphic record not including the three-dimensional graphic data of the map data, as shown in FIG. A three-dimensional observation target map is formed by arranging the three-dimensional shape 821 indicated by the three-dimensional graphic data of the graphic record including the three-dimensional graphic data, and the three-dimensional observation target map is determined based on the previously determined viewpoint position 800. This is done by drawing a map observed according to the viewing direction 801 and the viewing angle.

On the other hand, when it is determined that the countryside region (step 710), the map of the three-dimensional expression is drawn without considering the three-dimensional shape of the building figure in consideration of the three-dimensional topography (step 720).
That is, the drawing of the map of the three-dimensional representation of the rural area is shown in FIG. 8d2 at each position on the two-dimensional map formed by the graphic indicated by each graphic record that does not include the three-dimensional graphic data of the map data. Thus, the elevation of the position indicated by the 3D terrain data of the map data is given to form the 3D observation target map 822, and this 3D observation target map is determined according to the previously determined viewpoint position, gaze direction, and viewing angle. This is done by drawing the observed map. However, in drawing a map of a three-dimensional representation of a rural area, the figure record of a building figure representing the shape of a building, a house, etc., is excluded from the drawing target, and it is excluded from the mountains and rivers. Only the area graphic representing the shape of the area on the terrain or the road graphic representing the road shape may be drawn.

In addition, when the three-dimensional terrain data is data indicating the altitude discretely in the longitude and latitude direction such as DEM, the altitude of each longitude and latitude coordinate is calculated by interpolation or the like.
Now, when the map of the three-dimensional representation is drawn in this way, an icon having a display position in the map display area is extracted based on the icon unit, and each extracted icon is drawn (step 714). ). Further, based on the character string unit, a character string having a display position in the map display area is extracted, each extracted character string is drawn (step 716), and a map image is completed.

  Then, it is determined whether or not the travel distance counter has exceeded a predetermined distance Thd (for example, 1 km) (step 718), and if not, processing from step 710 is performed. If the travel distance counter exceeds the predetermined distance Thd, the process returns to step 702 and the above processing is performed. Here, only when the travel distance counter exceeds the predetermined distance Thd, the process returns to step 702 to determine the urban area / country area. This determination result is frequently switched, and as a result, the map representation is switched. This is to avoid the frequent occurrence of.

Now, FIG. 9 shows an example of the navigation image displayed in the second embodiment.
FIG. 9 a is an example when the determination in step 706 is a rural area.
As shown in the drawing, this navigation image is set in the current position mark 902 indicating the current position set in the memory 106 or in the memory 106 on the map image 901 generated by the above three-dimensional representation map drawing process. The recommended route graphic 903 representing the recommended route is drawn.

Further, the map image 901 is a three-dimensional representation of the undulation of the terrain with a perspective by a perspective projection method.
Next, FIG. 9B is an example when the determination in step 706 is an urban area.
As shown in the drawing, this navigation image is set in the current position mark 902 indicating the current position set in the memory 106 or in the memory 106 on the map image 901 generated by the above three-dimensional representation map drawing process. The recommended route graphic 903 representing the recommended route is drawn.

Further, the map image 901 is a three-dimensional representation of a building shape such as a building with a perspective by a perspective projection method.
Here, as described above, in the present embodiment, the elevation angle in the line-of-sight direction used for drawing the map in the three-dimensional representation is the expression of the undulation of the terrain in the countryside region that generates the map image including the undulation expression of the terrain. It is set larger than the urban area where map images not included are generated. Therefore, in the expression of the undulation of the terrain in the country area, it is possible to suppress the hidden terrain from being hidden from the viewpoint by a hill near the viewpoint, and to provide a map expression with excellent visibility with depth. Will be able to do.

On the other hand, in an urban area where a large number of buildings exist, by generating a map image that does not represent such terrain relief, both the building figure and the terrain relief display are complicated. Can be suppressed.
However, the elevation angle in the gaze direction used to draw the map in three-dimensional representation is a representation of terrain relief in rural areas that generate map images that include terrain relief, depending on user preference and usage. You may make it set so that it may become smaller than the urban area which produces | generates the map image which does not contain.

The second embodiment of the present invention has been described above.
In the above embodiment, instead of determining the urban area / country area according to the number of building figures, that is, the number of figure records whose graphic object type is a building figure, other urban / country areas are determined. The determination of the urban area / country area may be performed using arbitrary possible information. For example, the number of graphic records that have 3D graphic data (number of buildings that can be expressed in 3D), road density, and the number of points where various types of information are registered in map data The determination of the urban area / country area may be performed according to the above.
By the way, the map image switching according to the urban area / country area in the first and second embodiments described above may be performed by the display map switching process by the process shown in FIG.
That is, first, the threshold value Thn is set to a predetermined value Std (step 1002). Then, the number of building figures in the determination area is obtained as the number of figure records whose graphic object type is a building figure and whose graphic display position is in the determination area (step 1004).
If the calculated number of building figures is larger than the threshold value Thn (step 1006), it is determined to be an urban area (step 1014), and the threshold value Thn is set to Std-OS to set the value of the threshold value Thn. Decrease and make it difficult to determine the countryside region (step 1016). Then, a map image corresponding to the urban area is generated as in the first and second embodiments (step 1012), and the process returns to step 1004.

  On the other hand, if the calculated number of building figures is smaller than the threshold value Thn (step 1006), it is determined as a rural area (step 1008), and the threshold value Thn is set to Std + OS to increase the threshold value Thn. Thus, it is more difficult to determine the urban area (step 1010). Then, a map image corresponding to the urban area is generated as in the first and second embodiments (step 1012), and the process returns to step 1004.

  Even in such a process, when the vehicle enters and leaves the boundary where the number of buildings in the required determination area is the threshold value Thn, the determination of the urban area / country area is frequently switched, and as a result, the map It is possible to suppress frequent switching of expressions.

It is a block diagram which shows the structure of the navigation apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the map data with which the navigation apparatus which concerns on 1st Embodiment of this invention is provided. It is a flowchart which shows the map image drawing process which concerns on 1st Embodiment of this invention. It is a figure which shows the light spot drawing form which concerns on 1st Embodiment of this invention. It is a figure which shows the example of a display screen which concerns on 1st Embodiment of this invention. It is a figure which shows the map data with which the navigation apparatus which concerns on 2nd Embodiment of this invention is provided. It is a flowchart which shows the three-dimensional map drawing process which concerns on 2nd Embodiment of this invention. It is a figure which shows the production | generation method of the map image of the three-dimensional expression performed in 2nd Embodiment of this invention. It is a figure which shows the example of a display screen which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the display map switching process which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Control apparatus, 3 ... GPS receiver, 4 ... Running state sensor, 5 ... Remote control, 6 ... Display apparatus, 21 ... Recording medium, 101 ... Map data buffer, 102 ... Map data reading process part, 103 ... Current state calculation 104, route search unit, 105, navigation image generation unit, 106, memory, 107, main control unit, 108, GUI control unit.

Claims (8)

A navigation device for displaying a map,
A map drawing means for drawing a map of a range to be displayed based on map data including data of a shape and a display position of a building figure used for representing a building on a map;
Display means for displaying the map drawn by the map drawing means;
Based on the map data, the number or density of the building figure having a display position within a predetermined area including at least a part of the range of the map to be displayed or a ratio of the area or area to the area is predetermined. Determining means for determining whether or not the level is higher than,
The map drawing means draws at least a part of the building figure in a high-luminance color when drawing a map for night, and the building is determined when the determining means determines that the predetermined level is not higher than the predetermined level. Drawing the building graphic so that the portion drawn with the high luminance color of the graphic is larger than the portion drawn with the high luminance color of the building graphic when the determining means determines that the level is higher than a predetermined level. A navigation device characterized by A navigation device for displaying a map,
A map drawing means for drawing a map of a range to be displayed based on map data including data of a shape and a display position of a building figure used for representing a building on a map;
Display means for displaying the map drawn by the map drawing means;
Based on the map data, the number or density of the building figure having a display position within a predetermined area including at least a part of the range of the map to be displayed or a ratio of the area or area to the area is predetermined. Determining means for determining whether or not the level is higher than,
The map drawing means, when the determination means determines that the level is equal to or higher than the predetermined level, based on the map data, a two-dimensional terrain representation that is a map having a two-dimensional shape only in the longitude and latitude directions The map data is drawn when an image obtained when the map is observed from the viewpoint above the two-dimensional terrain expression map is drawn as a map displayed by the display unit, and the determination unit determines that the map is not higher than the predetermined level. The display means displays an image obtained when a three-dimensional terrain expression map, which is a map having a three-dimensional shape in the longitude and latitude elevation direction, is observed from the viewpoint above the three-dimensional terrain expression map based on Draw as a map,
The navigation apparatus according to claim 2, wherein the two-dimensional terrain representation map includes a three-dimensional figure representing a building arranged on the terrain having the two-dimensional shape. The navigation device according to claim 2,
The navigation device according to claim 3, wherein the three-dimensional terrain expression map does not include a three-dimensional figure representing the building. A navigation device for displaying a map,
A map drawing means for drawing a map of a range to be displayed based on map data including data of a shape and a display position of a building figure used for representing a building on a map;
Display means for displaying the map drawn by the map drawing means;
Based on the map data, the number or density of the building figure having a display position within a predetermined area including at least a part of the range of the map to be displayed or a ratio of the area or area to the area is predetermined. Determining means for determining whether or not the level is higher than,
The map drawing means, when the determination means determines that the level is equal to or higher than the predetermined level, based on the map data, a two-dimensional terrain representation that is a map having a two-dimensional shape only in the longitude and latitude directions The map data is drawn when an image obtained when the map is observed from the viewpoint above the two-dimensional terrain expression map is drawn as a map displayed by the display unit, and the determination unit determines that the map is not higher than the predetermined level. The display means displays an image obtained when a three-dimensional terrain expression map, which is a map having a three-dimensional shape in the longitude and latitude elevation direction, is observed from the viewpoint above the three-dimensional terrain expression map based on Draw as a map,
When the map drawing unit determines that the elevation angle in the direction of the line of sight of observation from the viewpoint is not equal to or higher than the predetermined level according to the determination result of the determination unit, A navigation device characterized in that the elevation angle is set to be larger than when it is determined that the level is equal to or higher than the level. A computer program that is read and executed by a computer installed in an automobile,
In the computer,
Based on map data including data on the shape and display position of the building graphic used to represent the building on the map, within a predetermined area including at least a part of the range of the map on which the map is displayed A determination step of determining whether the number or density of the building figure having a display position or an area or a ratio of the area to the area is equal to or higher than a predetermined level;
Drawing at least a part of the building figure in a high-luminance color when drawing a map of a range for which the map is to be displayed based on the map data; In addition, when it is determined in the determination step that the level is not equal to or higher than the predetermined level, a portion of the building graphic that is drawn with a high luminance color is determined to be equal to or higher than the predetermined level. A map drawing step for drawing the building figure so as to be larger than the portion drawn in the high brightness color of
A computer program for executing a display step for displaying the map drawn in the map drawing step . A computer program that is read and executed by a computer installed in an automobile,
In the computer,
Based on map data including data on the shape and display position of the building graphic used to represent the building on the map, within a predetermined area including at least a part of the range of the map on which the map is displayed A determination step of determining whether the number or density of the building figure having a display position or an area or a ratio of the area to the area is equal to or higher than a predetermined level;
Based on the map data, when the map of the range that is the target of displaying the map is drawn and it is determined in the determination step that the level is equal to or higher than the predetermined level, based on the map data A two-dimensional terrain representation map including a three-dimensional figure representing a building, which is arranged on the terrain having the two-dimensional shape, the terrain having only a longitude and latitude direction. The image obtained when observed from the viewpoint above the two-dimensional terrain expression map is drawn as the map, and when it is determined in the determination step that the level is not equal to or higher than the predetermined level, the terrain is processed based on the map data. An image obtained when a three-dimensional terrain representation map, which is a map having a three-dimensional shape in the direction of elevation, is observed from the viewpoint above the three-dimensional terrain representation map is defined as the map. And map drawing step of drawing,
A computer program for executing a display step for displaying the map drawn in the map drawing step . In a navigation device, a map display method for displaying a map based on map data,
The navigation device includes at least a part of a range of a map on which the map is displayed based on map data including data of a shape of a building figure used for representing a building on a map and a display position. A determination step of determining whether the number or density of the building figures having a display position in a predetermined area or the ratio of the area or the area to the area is equal to or higher than a predetermined level;
A map drawing step in which the navigation device draws a map of a range to be displayed based on the map data;
The navigation device has a display step of displaying the map drawn in the map drawing step;
In the map drawing step, when drawing a map for night, at least a part of the building figure is drawn in a high luminance color, and the building is determined to be not higher than the predetermined level in the determining step Drawing the building graphic so that the portion drawn in the high luminance color of the graphic is larger than the portion drawn in the high luminance color of the building graphic when the determination step determines that the level is higher than a predetermined level. The map display method characterized by performing. In a navigation device, a map display method for displaying a map based on map data,
The navigation device includes at least a part of a range of a map on which the map is displayed based on map data including data of a shape of a building figure used for representing a building on a map and a display position. A determination step of determining whether the number or density of the building figures having a display position in a predetermined area or the ratio of the area or the area to the area is equal to or higher than a predetermined level;
A map drawing step in which the navigation device draws a map of a range to be displayed based on the map data;
The navigation device has a display step of displaying the map drawn in the map drawing step;
In the map drawing step, when it is determined in the determination step that the level is equal to or higher than the predetermined level, a two-dimensional terrain representation that is a map having a two-dimensional shape only in the longitude and latitude directions based on the map data When an image obtained when the map is observed from the viewpoint above the two-dimensional terrain expression map is drawn as the map, and it is determined that the map is not equal to or higher than the predetermined level in the determination step, Draw the image obtained when observing a 3D terrain representation map, which is a map having a 3D shape in the longitude and latitude elevation direction, from the viewpoint above the 3D terrain representation map, as the map,
The map display method, wherein the two-dimensional terrain representation map includes a three-dimensional figure representing a building arranged on the terrain having the two-dimensional shape.