JP4644451B2 - Navigation device and mountain range display method - Google Patents

Description

  The present invention relates to a navigation device and a mountain range display method, and is particularly suitable for a navigation device having a function of displaying a bird's-eye view map in three dimensions.

  In general, a navigation device that guides driving of a vehicle not only displays a map around the current location, but also has a function of automatically setting and guiding a guidance route from the current location to the destination by specifying the destination. ing. This route guidance function uses map data to automatically search the route with the lowest cost from the current location to the destination by performing a simulation such as the breadth-first search (BFS) method or Dijkstra method, and guides the searched route. Set as a route.

  After the guide route is set, the guide route is drawn thickly with a different color so that it can be distinguished from other roads on the map image while the vehicle is running. And, by instructing the left and right turn along the guidance route, especially at the intersection (displaying an enlarged view of the intersection or guiding the direction of travel by voice), the driver can be quickly and safely to the destination, In addition, it can be surely guided.

In this type of navigation device, various research and development have been conducted so that the driver can more easily use the vehicle and can more reliably guide to the destination. As one of the technologies for that purpose, a bird's-eye view display for displaying a map in a state of looking down from behind the vehicle position to give a sense of perspective, or a three-dimensional stereoscopic image of a building or the like is displayed on the bird's-eye view map. There is a stereoscopic display function. A technique for displaying distant mountain ranges in a bird's eye view has also been proposed (see, for example, Patent Document 1).
Japanese Patent No. 3468656

  When attempting to display a mountain range with an image made up of photographs, pictures, etc., a large-capacity memory is required to store a large amount of image data. For this reason, the technique described in Patent Document 1 does not have mountain-level image data, and is configured to draw mountain ranges by calculation based on two-dimensional map data. That is, two-dimensional map data is configured for each of a plurality of standard area meshes defined by longitude lines and latitude lines at regular intervals, and elevation data is provided at the four corners of the mesh. Based on the elevation data, a three-dimensional mountain range obtained when viewing a three-dimensional map is displayed.

  According to the technique described in Patent Document 1, mountains can be displayed by storing elevation data at the four corners for each area divided at regular intervals. Therefore, the amount of data can be reduced as compared with the case of storing mountains of image data. It is possible to reduce. However, when displaying a bird's-eye view from the position of the vehicle to a distant place, a very large number of partitioned areas are included in the display range, and the amount of data increases even for two-dimensional map data. Since a lot of data must be processed to draw a mountain range, the drawing process inevitably takes time and the drawing performance deteriorates.

  Further, when displaying a bird's-eye view from the vehicle position to a distant place, map data having a large scale is used, so that there is a problem that a map near the vehicle position cannot be displayed in detail.

The present invention has been made to solve such a problem, and when displaying a mountain range in a bird's-eye view from the vehicle position to a distant place, the drawing processing time can be shortened to improve the performance. The purpose is to.
It is another object of the present invention to display a map near the vehicle position in detail in front of the screen (lower side) and to display distant mountain ranges in an easy-to-understand manner at the back (upper side) of the screen.

In order to solve the above-described problems, in the present invention, map data having an altitude value for each of a plurality of regions partitioned in a mesh shape is prepared by changing the mesh size for each map scale. . Based on the map data of multiple scales, a common mesh that traverses the maps of multiple scales is defined separately from the meshes of the maps of the multiple scales. Based on the included elevation values, the elevation values in each area of the common mesh are obtained , and the mountains are displayed by drawing each area using the common mesh .

According to the present invention configured as described above, when displaying a mountain range in a bird's-eye view from the vehicle position to a distant place, a map of a small scale is used in a certain area close to the vehicle position, and the vehicle position is By using a large-scale map mesh in an area far from the vehicle, it is possible to use it in an area far from the vehicle position compared to the conventional technology that uses the same size mesh in all areas from the vicinity of the vehicle position to the distance. The number of partitioned areas can be reduced by using a larger mesh. As a result, the amount of data to be processed can be reduced, and the drawing processing time can be shortened to improve the performance.
In addition, according to the present invention, since drawing is performed for each continuous area of one common mesh, a scale area is drawn when each scale area is drawn using a plurality of scale meshes. It is possible to eliminate the discontinuous portion that appears at the boundary between them, and it is possible to display a mountain-like image in a smoothly connected state even at the joint of the scale.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of a navigation device according to the first embodiment. In FIG. 1, reference numeral 100 denotes a navigation control device, which controls the entire navigation device. Reference numeral 11 denotes a recording medium such as a DVD-ROM, which stores various types of map data necessary for map display, route search, and the like. Here, the DVD-ROM 11 is used as a recording medium for storing the map data, but other recording media such as a CD-ROM and a hard disk may be used.

  The map data recorded on the DVD-ROM 11 is a unit called a level from a high-level map (wide area scale) for overlooking a wide area to a low-level map (small area scale) describing a narrow area in detail. Are managed in layers. Each scale map is divided in units of rectangular areas called sections partitioned by predetermined longitude and latitude. Further, the map data of each scale is divided into a mesh shape at a predetermined interval corresponding to the scale, and has an altitude value for each of a plurality of areas partitioned by the mesh. For example, an altitude value is given to each intersection (four corners of each area) of the mesh.

  Reference numeral 12 denotes an operation unit such as a remote control, a touch panel, or an operation switch. The user sets various information (for example, a route guidance destination or waypoint) to the navigation control device 100, or performs various operations (for example, Menu selection operation, enlargement / reduction operation, manual map scrolling, display view selection operation such as planar map, bird's-eye view or 3D map, and numerical value input).

  Reference numeral 13 denotes a self-contained navigation sensor for measuring the current position of the vehicle. The distance sensor (vehicle speed sensor) 13a detects the moving distance of the vehicle by outputting one pulse for each predetermined travel distance, and the rotation angle of the vehicle. And an angular velocity sensor (relative azimuth sensor) 13b such as a vibrating gyroscope for detecting (moving azimuth). The self-contained navigation sensor 13 detects the relative position and direction of the vehicle by the distance sensor 13a and the angular velocity sensor 13b, and outputs the information to the navigation control device 100.

  Reference numeral 14 denotes a GPS receiver for measuring the current position of the vehicle. The GPS antenna 15 receives radio waves transmitted from a plurality of GPS satellites, and performs a three-dimensional positioning process or a two-dimensional positioning process to obtain the absolute position of the vehicle. The position and direction are calculated (the vehicle direction is calculated based on the current vehicle position and the current vehicle position one sampling time ΔT before). Then, the calculated information on the absolute position and direction of the vehicle is output to the navigation control device 100 together with the positioning time.

  Reference numeral 16 denotes an image display device that displays an image generated by the control of the navigation control device 100. On the screen of the image display device 16, map information around the vehicle is displayed together with a vehicle position mark and the like. When the bird's-eye view display is instructed, the map information around the vehicle and the distant mountain range are displayed in a bird's-eye view together with the vehicle position mark and the like. Further, when the guidance route is set, the guidance route is displayed on this map, and an enlarged view of the intersection is displayed when the position of the vehicle approaches the vicinity of the guidance intersection.

  Next, in the internal configuration of the navigation control apparatus 100, reference numeral 21 denotes a map buffer, which temporarily stores map data read from the DVD-ROM 11. This map buffer 21 corresponds to the map storage means of the present invention. Here, the map buffer 21 stores map data 51, 52, 53 of a plurality of scales (for example, three different scales) as shown in FIG.

  The map data 51, 52, 53 of each scale represents a map of a predetermined rectangular range centered on the own vehicle position 54, and the size of the stored predetermined range differs for each scale. For example, in the case of the map data 51 of 100 m scale, the range of 1 km square is stored in the map buffer 21 in the case of the map data 52 of 1 km scale, the range of 10 km square is in the case of the map data 53 of 10 km scale. .

  As described above, the map data 51, 52, 53 of each scale is divided into meshes at predetermined intervals according to the scale. In this embodiment, the map data 51, 52, 53 of each scale is divided into 80 parts in length and breadth to form a mesh. Therefore, the size of the plurality of areas 61, 62, 63 partitioned by the mesh is smaller as the map data 51 is smaller in scale, and is larger as the map data 53 is larger in scale. The altitude value is stored for each of the plurality of areas 61, 62, 63 partitioned by the respective meshes of the map data 51, 52, 53 of each scale.

  A ROM read control unit 22 controls reading of map data from the DVD-ROM 11. The ROM read control unit 22 inputs vehicle current position information after map matching processing from a map matching control unit 26 described later. Then, an instruction to read out a predetermined range of map data including the current vehicle position is output. As a result, a plurality of scales of map data necessary for map display and mountain range display are read from the DVD-ROM 11 by a predetermined range and stored in the map buffer 21.

  An external signal input unit 23 inputs an operation signal corresponding to the operation state from the operation unit 12. A vehicle position / orientation calculation unit 24 calculates an absolute vehicle position (estimated vehicle position) and vehicle direction based on data on the relative position and direction of the vehicle output from the self-contained navigation sensor 13. To do. A data storage unit 25 sequentially stores absolute position and direction data of the vehicle output from the GPS receiver 14.

  The map matching control unit 26 described above includes the map data read into the map buffer 21, the estimated vehicle position and vehicle orientation data based on the autonomous navigation sensor 13 calculated by the vehicle position / orientation calculation unit 24, and data. Using the vehicle position data and the vehicle orientation data from the GPS receiver 14 stored in the storage unit 25, map matching processing is performed for each vehicle travel distance by a projection method or the like, and the travel position of the vehicle is determined from the map data. Correct the position on the road.

  The self-contained navigation sensor 13, the GPS receiver 14, the vehicle position / orientation calculation unit 24, the data storage unit 25, and the map matching control unit 26 constitute the vehicle position detection means of the present invention.

  A map drawing unit 27 generates map image data necessary for displaying a map on the image display device 16 based on the map data stored in the map buffer 21. The map drawing unit 27 draws a map based on map data of a plurality of scales stored in the map buffer 21 when a mode for displaying a bird's eye view is designated. At this time, the map near the vehicle position is drawn in detail on the front side (lower side) of the screen based on the map data on the narrow area scale. A map is drawn on the back (upper side) of the screen based on map data on a wide scale.

  Further, when the mode for displaying the bird's eye view is designated, the map drawing unit 27 gives height information based on the altitude value to a plurality of areas partitioned by the mesh of the map data, and the height information is given to the height information. Each area of the mesh is drawn with corresponding color information. At this time, the map drawing unit 27 draws a plurality of areas of a plurality of meshes corresponding to each scale using color information corresponding to each height information, using map data of a plurality of scales. Furthermore, a mountain range is drawn by performing gradation processing so that the color assigned to each region changes smoothly. The map drawing unit 27 corresponds to drawing means of the present invention.

  The contents of the mountain range drawing process by the map drawing unit 27 will be specifically described with reference to FIG. As shown in FIG. 3A, the map data is divided into meshes, and the four corners of each region defined by the mesh (in FIG. 3A, the four corners of one region are indicated by ●). Is given an elevation value. First, as shown in FIG. 3B, the map drawing unit 27 gives height information proportional to the altitude value to the four corners of the region, and draws the region three-dimensionally. This is performed for all regions in the mesh.

  Next, as shown in FIG. 3C, color information corresponding to the height information is given to each region, and each region is drawn by the color. Specifically, since mountains are displayed, green color information is basically given, but the brightness is changed according to the height. For example, a darker green is given to the higher part and a brighter green is given to the lower part. More specifically, an RGB value whose brightness is changed according to height information is determined, and each region is drawn with a color specified by the RGB value. Finally, as shown in FIG. 3D, the gradation display quality is improved by performing gradation processing so that the color given to each region changes smoothly.

  Next, reference numeral 28 denotes a VRAM (video RAM), which temporarily stores the map image data generated by the map drawing unit 27. A read control unit 29 controls reading of map image data from the VRAM 28. That is, the map image data generated by the map drawing unit 27 is temporarily stored in the VRAM 28, and the map image data for one screen is read by the read control unit 29.

  Reference numeral 30 denotes an operation screen generation unit that generates and outputs an operation screen necessary for performing various operations using the operation unit 12. Reference numeral 31 denotes various mark generation units that generate and output vehicle position marks displayed at the vehicle position after the map matching processing, various landmarks that display a gas station, a convenience store, and the like.

  Reference numeral 32 denotes an image composition unit, which superimposes each image data output from each of the operation screen generation unit 30 and the various mark generation units 31 on the map image data read by the read control unit 29, and performs image composition. The image is output to the image display device 16. As a result, the synthesized image is displayed on the screen of the image display device 16.

  Next, a description will be given of the operation of displaying mountains in the navigation device configured as described above. FIG. 4 is a flowchart illustrating a processing procedure of the mountain range display method according to the first embodiment. The flowchart shown in FIG. 4 shows the operation when a bird's eye view display is instructed.

  In FIG. 4, first, the ROM read control unit 22, based on the vehicle current position information input from the map matching control unit 26, maps data of a plurality of scales for a predetermined range including the vehicle current position. The data is read from the DVD-ROM 11 and stored in the map buffer 21 (step S1). Next, the map drawing unit 27 has a plurality of meshes corresponding to each scale based on map data of a plurality of scales stored in the map buffer 21 (map data 51, 52, 53 in the example of FIG. 2). Height information based on elevation values is given to the plurality of areas 61, 62, and 63, and a plurality of areas are drawn with color information corresponding to the height information (step S2).

  Further, the map drawing unit 27 performs gradation processing applied to the colored areas 61, 62, and 63 so that the color changes smoothly (step S3). Although not shown in the flowchart, a map from the vicinity of the vehicle position to the far side is drawn based on map data of a plurality of scales. The map image data based on the bird's eye view drawn in this way is stored in the VRAM 28 (step S4). Then, under the control of the reading control unit 29, the size of one screen is cut out from the drawing data stored in the VRAM 28 and output to the image display device 16 (step S5). With the above processing, a map including mountain ranges as shown in FIG. 5 is displayed on the display screen of the image display device 16.

  As described above in detail, according to the first embodiment, the mountain ranges are displayed using the map data 51, 52, 53 of a plurality of scales having different mesh sizes. Compared to conventional technology that uses map data of the same scale (same size mesh) in all areas from to far, the number of partition areas is reduced by using a larger mesh in areas far from the vehicle position. be able to. As a result, the amount of data to be processed can be reduced, the drawing processing time can be shortened, and the performance can be improved.

  Further, according to the first embodiment, in a certain area close to the own vehicle position, the map around the own vehicle position can be displayed in detail by drawing the map using the map data 51 having a small scale. . In addition, by drawing a mountain range using a mesh of map data 52, 53 with a large scale in an area away from the vehicle position, it is possible to display a mountain range far away. Thereby, the detailed map near the own vehicle position and the distant mountain range can be displayed in one screen.

  Next, a second embodiment of the present invention will be described. The functional configuration of the navigation device according to the second embodiment is the same as that shown in FIG. However, the mountain drawing method by the map drawing unit 27 is different from that of the first embodiment. This will be described with reference to FIG. FIG. 6 is an image diagram showing the relationship between multi-scale map data and meshes according to the second embodiment.

  As shown in FIG. 6, in the second embodiment, the map drawing unit 27 has a plurality of scale map data 51, 52, 52, separately from the meshes of the plurality of scale map data 51, 52, 53. A common mesh 71 crossing 53 is defined. The size of the common mesh 71 (the size of each partition area) is set to be approximately the same as or slightly larger than the size of the mesh of the map data 53 having the largest scale, for example.

  And the map drawing part 27 calculates | requires the elevation value in each intersection of the common mesh 71 by calculation based on the elevation value in each intersection of the some mesh which the map data 51, 52, 53 of several scales has. Specifically, when the elevation value of a certain intersection of the common mesh 71 is obtained, a plurality of intersections surrounding the intersection to be obtained by the common mesh 71 among the mesh intersections of the map data 51, 52, and 53 are enclosed. The elevation value at the intersection of the common mesh 71 is obtained by performing an interpolation operation using the elevation value at the intersection. When obtaining the elevation value of the intersection point of the common mesh 71 near the boundary between the map data 51, 52, 53 of each scale, the interpolation calculation is performed using the elevation value at the intersection point of the mesh possessed by the map data of both scales. .

  When the elevation value at each intersection of the common mesh 71 is obtained in this way, each region of the common mesh 71 is drawn by the same calculation as in the first embodiment using the elevation value. That is, height information based on the altitude value of the common mesh 71 is given to each area of the common mesh 71, and each area of the common mesh 71 is drawn with color information corresponding to the height information.

  In the first embodiment described above, mountain ranges are displayed using meshes of three different scales. Therefore, discontinuities occur in the drawing area at the boundary portions of different meshes, and the display of mountain ranges becomes discontinuous. On the other hand, in the second embodiment, one common mesh is obtained from three different scale meshes, and drawing is performed on each continuous area of the common mesh. This makes it possible to simultaneously display a detailed map near the vehicle position and a distant mountain range on one screen using map data of multiple scales, while eliminating discontinuous parts at the boundaries of each scale. it can.

  FIG. 7 is a diagram illustrating another example of the common mesh. The common mesh may be a spider web-like mesh as shown in FIG. 7 in addition to the lattice-like mesh shown in FIG. In the common mesh shown in FIG. 7, the closer to the own vehicle position, the narrower the partitioned area, and the farther from the own vehicle position, the wider the partitioned area. For example, the size of the partition area closest to the vehicle position is substantially the same as the partition area of the map data 51 having the smallest scale shown in FIG. 6, for example, a size of 50 m square. Further, the size of the partition region farthest from the vehicle position is substantially the same as the partition region of the map data 53 having the largest scale shown in FIG. 6, for example, a size of 1 km square.

  In the case of bird's eye view display or 3D display, the range that is visible closer to the vehicle position is narrower, and the range that is visible farther away from the vehicle position is wider. Therefore, it is possible to display the mountain range more realistically by setting the common mesh in a spider web shape according to such an actual field of view. Also, when the reading control unit 29 cuts out an area for one screen, the processing can be simplified because it is only necessary to cut out a rectangular area. Moreover, the number of areas used for processing can be reduced by setting the section area to be narrower as it is closer to the own vehicle position and the section area to be wider as it is farther from the own vehicle position.

  Next, a third embodiment of the present invention will be described. FIG. 8 is a block diagram illustrating a configuration example of a navigation device according to the third embodiment. In FIG. 8, the same reference numerals as those shown in FIG. 1 have the same functions, and therefore redundant description is omitted here.

  In the third embodiment, the map drawing unit 27 inputs vehicle current position information from the map matching control unit 26. Then, based on the map data stored in the map buffer 21 and the vehicle position information input from the map matching control unit 26, height information based on the altitude value is given to a plurality of areas in the mesh. A plurality of regions are drawn with color information corresponding to the height information and distance information from the vehicle position.

  Specifically, since mountains are displayed, green-based color information is basically provided, but the brightness is changed according to the height and the saturation is changed according to the distance from the vehicle position. For example, a darker green is given to the higher part and a brighter green is given to the lower part. Further, the closer to the vehicle position, the darker the green, and the farther from the vehicle position, the lighter the green. More specifically, RGB values with different brightness and saturation are determined according to height information and distance information, and each region is drawn with a color specified by the RGB values.

  Thus, in addition to the height information based on the altitude value in each area of the mesh, if each area of the mesh is drawn with color information corresponding to the distance information from the vehicle position, the height of the mountain In addition to changing the color accordingly, it is possible to change the color and display the mountain range according to the distance from the vehicle position to the mountain. As a result, as shown in FIG. 9, the mountain ranges can be displayed in an easy-to-understand manner so that a close mountain and a distant mountain can be clearly distinguished. At this time, it is possible to make it appear as if it is far away by expressing a distant mountain in a pale color.

  As mentioned above, although 1st-3rd embodiment was demonstrated, all of these showed only an example of actualization in practicing the present invention, and this limits the technical scope of the present invention. It should not be interpreted. In other words, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

  For example, in the first to third embodiments, the example using the map data of three different scales has been described. However, the map and the mountain range are displayed using the map data of two or more different scales. Anyway.

  In the third embodiment, the brightness is changed according to the height of the mountain, and the saturation is changed according to the distance from the vehicle position. Conversely, the brightness is changed according to the height of the mountain. The saturation may be changed, and the brightness may be changed according to the distance from the vehicle position. Further, the hue may be changed according to the height of the mountain or the distance from the vehicle position.

  INDUSTRIAL APPLICABILITY The present invention is useful for a navigation device having a function of displaying a bird's-eye view map in three dimensions.

It is a block diagram which shows the structural example of the navigation apparatus by 1st Embodiment. It is an image figure which shows the structural example of the map data of multiple scale by 1st Embodiment. It is a figure for demonstrating the content of a mountain range drawing process. It is a flowchart which shows the process sequence of the mountain range display method. It is a figure which shows the example of the navigation screen displayed by 1st Embodiment. It is an image figure which shows the relationship between the multiple scale map data and common mesh by 2nd Embodiment. It is a figure which shows the other example of the common mesh by 2nd Embodiment. It is a block diagram which shows the structural example of the navigation apparatus by 3rd Embodiment. It is a figure which shows the example of the navigation screen displayed by 3rd Embodiment.

Explanation of symbols

13 Autonomous Navigation Sensor 14 GPS Receiver 21 Map Buffer 24 Vehicle Position / Direction Calculation Unit 25 Data Storage Unit 26 Map Matching Control Unit 27 Map Drawing Unit

Claims (5)

A map data including a map of a plurality of scales, and each scale map is divided into meshes at a predetermined interval corresponding to the scale, and each of a plurality of mesh regions divided at the predetermined intervals Map storage means for storing map data having elevation values at
Based on the map data stored in the map storage means, a common mesh that traverses the maps of the plurality of scales is defined separately from the meshes of the maps of the plurality of scales. Based on the altitude values included in each area of the multiple meshes that the map has, obtain the altitude value in each area of the common mesh, and give the height information based on the altitude value to each area of the common mesh , the navigation device being characterized in that a drawing means for drawing the respective regions of the common mesh with color information anaphoric to the height information. The navigation device according to claim 1 , wherein the common mesh is a lattice mesh. The navigation device according to claim 1 , wherein the common mesh is a spider web-like mesh. 4. The navigation device according to claim 3, wherein the spider web-like mesh is configured such that the region is narrower as it is closer to the vehicle position, and the region is wider as it is farther from the vehicle position. Navigation devices, are divided into meshes by predetermined intervals each scale of the map corresponding to the scale, respectively, based on a plurality of scales of map data having a elevation value for each of a plurality of regions of the mesh, the Separate from each mesh of multiple scale maps, define a common mesh that traverses the multiple scale maps, and include elevation values contained in each area of the multiple meshes of the multiple scale maps. And calculating the elevation value in each area of the common mesh, giving height information based on the elevation value to each area of the common mesh, and each color of the common mesh according to color information corresponding to the height information. A first step of drawing an area ;
A mountain range display method, wherein the navigation device has a second step of cutting out the size of one screen from the drawing data obtained in the first step and displaying the mountain range on a display screen.

Images