JP2006208816A - Navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation system that enables a driver to easily recognize the current position and traveling direction of his or her vehicle. <P>SOLUTION: The navigation system is equipped with a display device 4 which displays a map and a control unit 3 which draws a mountain on a passenger's view-point map as a scene in the traveling direction drawn with the view point of a passenger in the vehicle and makes the display device 4 display it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a navigation system that displays its current position, guidance route, traffic jam prediction information, and the like together with a map, and more particularly to a technique for displaying a landscape in the traveling direction of the own vehicle from the viewpoint of a vehicle occupant.

  2. Description of the Related Art Conventionally, as one of navigation systems, a car navigation device that supports a driver so that a driver can easily reach a destination is known. This car navigation device acquires two-dimensional map data stored in a storage medium such as a CD (Compact Disc) or DVD (Digital Versatile Disk) or an HDD (Hard Disk Drive) device, and based on the acquired map data. A map containing roads, buildings, sky, etc. is displayed on the screen of the display device, and the current position of the vehicle and the direction in which the vehicle is facing are detected using GPS (Global Positioning System) or a gyro. Further, the traffic jam prediction information is displayed on the map using VICS (Vehicle information and Communication System) information and the like.

  As types of maps displayed by the car navigation device, 2D maps, bird's-eye views, occupant viewpoint maps, and the like are known. The 2D map is a two-dimensional map drawn as if the ground is viewed vertically from above. The bird's-eye view is a three-dimensional map drawn as if looking down at the ground in the direction of travel of the vehicle from above the driver, like a bird in the sky above. Further, the passenger viewpoint map is a three-dimensional map drawn as if the traveling direction was viewed from the viewpoint of the driver or passenger in the passenger seat. The occupant viewpoint map has a feature that the scenery close to the actual scenery seen from the driver's viewpoint is displayed, so that the correspondence between the map and the actual road can be intuitively understood.

  As a technique for displaying a three-dimensional map, Patent Document 1 discloses a map information display device in a navigation device capable of displaying mountains. In this map information display device, altitude data is stored in advance as map data, and the altitude data on the heel side is compared with the viewpoint on the horizon rather than on the pseudo horizon provided in the predetermined distant area when the bird's eye view is displayed. Acquired for each line-of-sight direction from. Then, the highest elevation data among them is used as data on the pseudo horizon, and bird's-eye view conversion is performed to perform map display.

  Further, Patent Document 2 discloses a navigation device that displays a three-dimensional map based on three-dimensional map information such as terrain and roads. And a navigation device that smoothly updates a landscape by resetting the line of sight. When the current position of the host vehicle is updated by the current position detection unit, the navigation device reads map data around the host vehicle from the map database via the data reading unit, and the host vehicle included in the map data. After referring to the surrounding terrain altitude data and resetting the viewpoint to a position higher than the terrain altitude by the viewpoint setting unit, the display processing unit performs coordinate conversion to display a perspective map viewed from the set viewpoint.

  As a technique for analyzing terrain based on map data, Patent Document 3 discloses a terrain information processing method and apparatus that can optimize the information distribution in the target region and improve the accuracy of terrain analysis and the like. . This terrain information processing device converts terrain information into display information, terrain input means for inputting processing information from a large-capacity storage means for accumulating various terrain information at a plurality of scales, memory for storing the input information, A terrain display means, a terrain analysis means for performing a specified analysis process, an analysis result display means for converting the analysis result into display information, and an input / output means for instructing the processing contents and displaying the results. The terrain analysis means obtains the distribution of the terrain information in the analysis region, and optimizes the information with a small amount (large) of information with other scale terrain information, etc., and performs the target analysis. Thereby, homogeneity of terrain information processing, particularly accuracy of terrain analysis can be improved, and suitable information desired by the user can be provided. Further, in this Patent Document 3, although it is not realized as a navigation system, contour lines are obtained from map data, and an intersection with the contour line is obtained by a line segment connecting arbitrary two points set by the user. A technique for displaying a sectional view of the ground to be divided is also disclosed.

Japanese Patent Laid-Open No. 10-307034 JP-A-10-143066 Japanese Patent No. 2644935

  By the way, when recognizing the current position and direction of the own vehicle, the driver checks the arrangement of surrounding buildings and specific facilities (for example, Tokyo Tower). Therefore, the current position and direction of the vehicle cannot be recognized in places such as mountainous areas where there are few buildings and specific facilities. In addition, since the car navigation device is limited by hardware and software, it cannot be provided with map data having a large amount of information, and the drawing model needs to be deformed. For this reason, when a 3D map is displayed on the screen, although the picture is close to the actual background, the details of the location of the building and the pattern of the walls are different. It is not easy to recognize the position and the traveling direction.

  In order to solve such a problem, a method of drawing a mountain on the background is known. This method is not realized in an occupant viewpoint map that displays a landscape from the viewpoint of the driver, but is realized in a bird's eye view that displays a landscape from a viewpoint that is higher than the viewpoint of the driver. In the bird's-eye view, as shown in Patent Document 1 described above, the altitude of a terrain mesh that is a fixed distance away from the current position of the vehicle on the map is acquired and drawn as a background. With this method, the undulations of the mountain cannot be expressed in detail, and it is very different from the actual mountain, so the current location cannot be confirmed easily.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a navigation system that allows the driver to easily understand the current position and traveling direction of the host vehicle.

  In order to achieve the above object, the navigation system according to the present invention draws and displays a mountain on a display device that displays a map and an occupant viewpoint map that is a landscape in a traveling direction drawn from the viewpoint of the occupant of the vehicle. And a control device to be displayed on the device.

  According to the present invention, since the mountain is drawn and displayed on the occupant viewpoint map, which is a landscape in the traveling direction drawn from the viewpoint of the occupant of the vehicle, the driver can display the current position of the host vehicle and the progress of the vehicle. The direction can be easily understood.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a functional configuration of a navigation system according to Embodiment 1 of the present invention. This navigation system includes an input device 1, a storage device 2, a control device 3, and a display device 4.

  The input device 1 inputs the current position of the host vehicle, the traveling speed, the direction of travel, and the like to the control device 3. The storage device 2 stores map data. The map data includes elevation data (contour line data), building data, road data, and the like. The map data stored in the storage device 2 is read out by the control device 3.

  The control device 3 corresponds to the mountain drawing data creating means of the present invention and controls the entire navigation system. For example, when the current position of the host vehicle and the direction of the traveling direction are input from the input device 1, the control device 3 reads map data around the current position of the host vehicle from the storage device 2, and the read map data Mountain drawing data for drawing a mountain is generated based on the included altitude data and sent to the display device 4. The display device 4 displays an occupant viewpoint map having a mountain in the background based on the mountain drawing data sent from the control device 3.

  FIG. 2 is a block diagram showing a detailed hardware configuration of the navigation system shown in FIG. In the navigation system according to the first embodiment, the control device 3 is configured using a CPU (Central Processing Unit), but may be configured using hardware logic instead of the CPU.

  The navigation system includes a GPS sensor 11, a gyro sensor 12, a vehicle speed sensor 13, an external storage device 21, a CPU 31, a memory 32, and a display control device 33 connected by a bus 10. A display device 41 is connected. The GPS sensor 11, the gyro sensor 12, and the vehicle speed sensor 13 correspond to the input device 1 described above, and the external storage device 21 corresponds to the storage device 2. The CPU 31, the memory 32, and the display control device 33 correspond to the control device 3, and the display device 41 corresponds to the display device 4.

  The GPS sensor 11 performs a predetermined calculation based on a GPS signal obtained by receiving radio waves transmitted from a plurality of GPS satellites (not shown) existing in the satellite orbit, thereby performing the current position of the host vehicle. Is detected. The current position (latitude, longitude, and altitude) detected by the GPS sensor 11 is sent to the CPU 31 via the bus 10 as current position data. The gyro sensor 12 detects the direction in which the vehicle is traveling. The direction in the traveling direction detected by the gyro sensor 12 is sent to the CPU 31 via the bus 10 as direction data. Each time the vehicle speed sensor 13 detects that the vehicle has traveled a predetermined distance, it generates a vehicle speed pulse and outputs it as vehicle speed data. The vehicle speed data output from the vehicle speed sensor 13 is sent to the CPU 31 via the bus 10.

  The external storage device 21 includes a drive device or HDD device for a storage medium such as a CD or a DVD. The external storage device 21 stores a car navigation program 22, a mountain drawing program 23, map data 24, and an operating system (OS) 25. The mountain drawing program 23 is a part of the car navigation program 22. The contents stored in the external storage device 21 are read by the CPU 31 as necessary.

  The CPU 31 transmits and receives data to and from the GPS sensor 11, gyro sensor 12, vehicle speed sensor 13, external storage device 21, memory 32 and display control device 33 via the bus 10. Control. The memory 32 temporarily holds various data. This memory 32 is accessed by the CPU 31. The display control device 33 is composed of a dedicated computing unit that performs computation for displaying a mountain. The display control device 33 generates display data for displaying a mountain based on the mountain drawing data sent from the CPU 31, and sends it to the display device 41. The display device 41 is composed of, for example, a liquid crystal display device, and displays an occupant viewpoint map including a mountain in the background in accordance with display data sent from the display control device 33.

  Next, the storage format of the elevation data (contour line data) included in the map data used in the navigation system according to the first embodiment in the external storage device 21 will be described. FIG. 3 is a diagram showing a storage format of elevation data included in the map data stored in the external storage device 21. The elevation data is composed of an elevation list prepared for each elevation, and each elevation list is composed of a plurality of points representing the elevation. Each of the plurality of points is defined by coordinate values (coordinate x, coordinate y, altitude h), and an address is assigned to each of the plurality of points. Contour lines for one altitude are formed by sequentially connecting a plurality of points included in each elevation list.

  Next, referring to the flowchart shown in FIG. 4 for the outline operation of the navigation system according to the first embodiment of the present invention configured as described above, focusing on the mountain drawing process executed by the mountain drawing program 23. While explaining.

  In the mountain drawing process, first, a reference point and a gaze destination direction are acquired (step ST10). Specifically, the CPU 31 calculates the current position of the host vehicle based on the current position data acquired from the GPS sensor 11, the azimuth data acquired from the gyro sensor 12, and the vehicle speed data acquired from the vehicle speed sensor 13, and is used as a reference point. At the same time, the azimuth of the traveling direction of the host vehicle is calculated and set as the azimuth of the gaze destination direction. FIG. 5 shows a state where there is a mountain having a contour line with an altitude of 100 m and a contour line with an altitude of 200 m in the traveling direction of the own vehicle (the direction of the gaze point) with the current position of the host vehicle as a reference point. In the first embodiment, the current position of the host vehicle is used as the reference point. However, the reference point is not limited to the current position of the host vehicle, and the user may set an arbitrary position. it can. For example, the reference point can be configured to set a position away from the vehicle by a predetermined distance backward.

  Next, a line segment B is obtained (step ST11). That is, as shown in FIG. 5, a line segment that is orthogonal to the half line A extending in the traveling direction starting from the current position (reference point) of the own vehicle and that is located at a predetermined distance from the current position of the own vehicle. B is required. The line segment B does not need to be strictly orthogonal to the half line A, and can be configured to intersect at an angle close to orthogonal. The crossing referred to in the present invention includes the case of crossing at a right angle and an angle close to the right angle.

  Next, an intersection point between the line segment B and the contour line is obtained (step ST12). FIG. 6 is a diagram for explaining a method of obtaining the intersection point between the line segment B and the contour line. The intersection point is calculated as follows. First, xy coordinates of two adjacent points (for example, point 1 and point 2) are acquired from the altitude data included in the map data, and the presence / absence of an intersection between a straight line connecting these two points and the line segment B is checked. When an intersection exists, the value of the three-dimensional coordinates (x, y, h) of the intersection is stored in the memory 32 as intersection data. Next, the xy coordinates of the next two adjacent points (for example, point 2 and point 3) are acquired from the elevation data, and the presence or absence of the intersection of the straight line connecting these two points and the line segment B is examined. If an intersection exists, the three-dimensional coordinates (x, y, h) of the intersection are stored in the memory 32 as intersection data. Similarly, the presence or absence of an intersection with the line segment B is examined between all two adjacent points for one contour line, and the intersection is obtained. When the calculation of the intersection point for one contour line is completed, the intersection point for the next contour line is calculated.

  In the process of step ST12, for example, as shown in FIG. 7, if the map has a contour line with an altitude of 100 m and a contour line with an altitude of 200 m, intersection points 1 and 2 are obtained as the intersection points of the contour line with an altitude of 100 m and line segment B Intersection 3 and intersection 4 are obtained as intersections between the contour line of the altitude of 200 m and the line segment B. In this case, since the intersection is calculated for each contour line, the three-dimensional coordinates (x, y, h) of the intersections 1 to 4 are stored in the memory 32 as shown in FIG. Stored in the order of intersection 3 → intersection 4.

  Next, a two-dimensional mountain is calculated using the intersection obtained in step ST12 (step ST13). That is, by drawing the z-axis values (elevation = h) of a plurality of intersection data stored in the memory 32 on the z coordinate, mountain drawing data representing a two-dimensional mountain having no thickness is generated. At this time, the intersection data stored in the memory 32 are acquired two by two in order from the top, and the shape of the mountain is drawn.

  Assuming that intersection data as shown in FIG. 8 is stored in the memory 32, first, the coordinate values of the intersection 1 and the intersection 2 are acquired from the memory 32, and a mountain is drawn. As a result, a mountain shape as shown in FIG. 9A is obtained. Next, the coordinates of the intersection 2 and the intersection 3 are acquired from the memory 32 and a mountain is drawn. As a result, a mountain shape as shown in FIG. 9B is obtained. Next, the coordinates of intersection 3 and intersection 4 are acquired from the memory, and a mountain is drawn. As a result, a mountain shape as shown in FIG. 9C is obtained, and this is finally the mountain shape to be drawn. Accordingly, a mountain having a shape far from the actual mountain is drawn.

  In order to avoid such a situation, in the first embodiment, the intersection data stored in the memory 32 for each contour line is rearranged according to the value of the x coordinate or the y coordinate. In this process, as shown in FIG. 10, the rearrangement is performed according to the angle θ formed by the east direction (direction) and the traveling direction (direction) of the host vehicle. That is, when the angle θ is 0 ° <θ <180 ° or 180 ° <θ <360 °, the rearrangement is performed in descending order of x-coordinate values. When the angle θ is 0 ° or 180 °, the x-coordinate values are the same at all points, and therefore the y-coordinate values are rearranged in descending order. By this processing, the intersection data stored in the memory 32 is rearranged in the order of intersection 1 → intersection 3 → intersection 4 → intersection 2 as shown in FIG.

  Next, the altitude of the intersection that becomes the end point of the mountain is corrected to an altitude close to the ground surface. As shown in FIG. 12A, since the end points of the mountain also have an altitude, when the mountain is drawn using the altitude, all the ends of the mountain are displayed as cliffs as shown in FIG. Therefore, a process is performed in which the altitude of the intersection which is the end point of the mountain, that is, the intersection stored first in the memory 32 and the altitude stored last is replaced with a predetermined altitude close to the ground surface. Thereby, as shown in FIG.12 (c), it becomes possible to draw the edge of a peak gently.

  It is also possible to correct the altitude of the intersection that is the end point of the mountain by subtracting the altitude of the current position of the vehicle from the altitude of the mountain end point. For example, if the altitude at the current position of the host vehicle is 80 m, 80 m can be subtracted from the altitude 100 m at point 1 in FIG. 12A to correct the altitude at point 1, which is the end point of the mountain, to 20 m. In this case, the altitude of the current position of the vehicle can be calculated based on the map data or the GPS data from the GPS sensor 11. In this way, by correcting the altitude of the end point of the mountain, the shape of the mountain to be drawn can be brought close to the shape actually seen by the driver, and a mountain with a more natural shape can be drawn.

  Next, a process of drawing from the occupant's viewpoint is executed (step ST14). That is, the intersection data stored in the memory 32 is processed for drawing by the display control device 33 and displayed on the display device 41, so that the mountain can be displayed from the viewpoint of the passenger. Since the intersection obtained by the above processing is a point where the contour line and the line segment B intersect, the mountain to be drawn is a two-dimensional plate-like mountain having no depth, as shown in FIG. A two-dimensional plate-like mountain refers to a cross-sectional view of a flat mountain having no thickness. When viewed from the side of the traveling direction of the vehicle, the mountain is as shown in FIG. When this is drawn on the screen from the viewpoint of the passenger, it is displayed as shown in FIG.

  Next, the details of the mountain drawing process performed by the mountain drawing program 23 to realize the above-described operation will be described with reference to the flowchart shown in FIG. In the mountain drawing process, first, the current position of the host vehicle is input (step ST20). That is, the CPU 31 acquires current position data from the GPS sensor 11. The current position of the vehicle specified by the current position data is determined as a reference point. Next, the direction of the traveling direction of the host vehicle is input (step ST21). That is, the CPU 31 determines the azimuth in the traveling direction (gaze destination direction) of the host vehicle based on the azimuth data acquired from the gyro sensor 12 and the vehicle speed data acquired from the vehicle speed sensor 13.

  Next, a half line A is obtained (step ST22). Specifically, the CPU 31 starts from the current position of the own vehicle based on the reference point determined in step ST20 and the direction of the traveling direction (gaze destination direction) of the own vehicle determined in step ST21. A half straight line A extending in the direction of the traveling direction is obtained. Next, a line segment B is obtained (step ST23). That is, the CPU 31 obtains a line segment B that is orthogonal to the half line A and is a predetermined distance away from the host vehicle.

  Next, acquisition of one elevation list is attempted (step ST24). Specifically, the CPU 31 tries to obtain one elevation list from the elevation data included in the map data 24 of the external storage device 21. Next, it is examined whether or not the altitude list has been acquired (step ST25). Here, if it is determined that the altitude list has been acquired, then acquisition of two adjacent points from the altitude list is attempted (step ST26). Next, it is checked whether or not two points have been acquired (step ST27). If it is determined that two points have been acquired, a linear equation connecting these two points is obtained (step ST28).

  Next, it is checked whether or not the straight line connecting the two points obtained in step ST28 and the line segment B intersect (step ST29). Here, when it is determined that they intersect, the intersection of the straight line connecting the two points and the line segment B is obtained and stored in the memory 32 (step ST30). Thereafter, the sequence returns to step ST26, and the same processing is repeated thereafter. Even when it is determined in step ST29 that the straight line connecting the two points does not intersect with the line segment B, the sequence returns to step ST26.

  During the repeated execution of these steps ST26 to ST30, if it is determined in step ST27 that the elevation list cannot be acquired, it is recognized that the processing for one contour line has been completed, and the sequence returns to step ST24. The process described above is repeated. If it is determined in step ST25 that the elevation list cannot be acquired during the repeated execution of steps ST24 to ST30, it is recognized that the processing for all the elevation lists is completed, and the sequence proceeds to step ST31. At this time, for example, as shown in FIG. 8, the three-dimensional coordinates (x, y, h) of intersection 1 to intersection 4 with respect to all contour lines are stored in memory 32 as intersection 1 → intersection 2 → intersection 3 → intersection 4 Stored in order.

  In step ST31, rearrangement of intersections is performed. That is, the CPU 31 rearranges the intersection data stored in the memory 32 according to the value of the x coordinate or the y coordinate (details are as described above). Next, the rearranged intersection points are stored in the memory 32 (step ST32). Thereby, for example, as shown in FIG. 11, intersection data rearranged in the order of intersection 1 → intersection 3 → intersection 4 → intersection 2 is obtained in the memory 32. By performing drawing based on the intersection data obtained in the memory 32, an occupant viewpoint map including a mountain in the background is displayed on the display device 41.

  As described above, according to the navigation system of the first embodiment of the present invention, the intersection of the line segment B and the contour line orthogonal to the half line A extending in the traveling direction starting from the current position of the own vehicle is acquired. The first intersection data and the last intersection data stored in the memory 32 are corrected so that they are close to the ground surface, and a mountain is drawn by using these intersection points. Mountains close to the background can be displayed.

Embodiment 2. FIG.
The navigation system according to Embodiment 2 of the present invention displays not only the mountains existing at a predetermined distance from the current position of the host vehicle but also the mountains existing at other distances. The functional configuration and hardware configuration of the navigation system according to the second embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

  The operation of the navigation system according to Embodiment 2 of the present invention will be described. FIG. 16 is a diagram for explaining the mountain drawing process of the navigation system according to the second embodiment. The current position of the host vehicle is used as a reference point, and the mountain m1 and the mountain in the traveling direction (gaze destination direction) of the host vehicle. The state where m2 exists is shown. The general operation of the navigation system according to the second embodiment is as follows. That is, the line segment B and the second distance that are orthogonal to the half line A extending in the traveling direction starting from the current position (reference point) of the own vehicle and that are separated from the current position of the own vehicle by the first distance A line segment B ′ existing at a position separated by a distance is obtained. Then, an intersection group c1 between the mountain m1 and the line segment B and an intersection group c2 between the mountain m2 and the line segment B ′ are acquired.

  Thereafter, as shown in FIG. 17A, a mountain m1 is drawn using the intersection group c1. Next, as shown in FIG. 17B, a mountain m2 is drawn using the intersection group c2. Next, as shown in FIG. 17C, the mountain m1 and the mountain m2 are combined and displayed. In this case, since the intersection group c2 exists at a position farther from the current position of the host vehicle than the intersection group c1, the mountain m2 formed by the intersection group c2 seems to exist behind the mountain m1 formed by the intersection group c1. Is displayed. That is, the part where the mountain m1 and the mountain m2 overlap is displayed so that a part of the mountain m2 is hidden by the mountain m1.

  In the example shown in FIGS. 16 and 17, the example in which the mountain is drawn using the two line segments B and B ′ that are orthogonal to the half line A has been described. However, the line segment that is orthogonal to the half line A is described. Is not limited to two, and can be three or more. By increasing the number of line segments orthogonal to the half line A, it is possible to draw a mountain closer to the actual landscape.

  Next, details of the mountain drawing process performed by the mountain drawing program for realizing the above-described operation will be described with reference to the flowchart shown in FIG. In addition, the same code | symbol is attached | subjected to the step which performs the process same as the mountain drawing process in the navigation system which concerns on Embodiment 1 shown in the flowchart of FIG. 15, and description is simplified.

  In the mountain drawing process, first, the current position of the host vehicle is input (step ST20). Next, the direction of the traveling direction of the host vehicle is input (step ST21). Next, a half line A is obtained (step ST22). Next, the count value i of the counter is initialized to zero (step ST40). This counter is provided inside the CPU 31 and is used to count the number of line segments orthogonal to the half line A. Next, it is checked whether or not the count value i exceeds a set value (step ST41). Here, the set value represents the number of line segments orthogonal to the half line A, and can be set in advance by the user.

  Next, a line segment B is obtained (step ST23). Next, acquisition of one elevation list is attempted (step ST24), and it is checked whether or not the elevation list has been acquired (step ST25). Here, if it is determined that the altitude list has been acquired, then it is attempted to acquire two adjacent points from the altitude list (step ST26), and it is checked whether two points have been acquired (step ST27). If it is determined that two points have been acquired, a linear equation connecting these two points is obtained (step ST28).

  Next, it is checked whether or not the straight line connecting the two points obtained in step ST28 and the line segment B intersect (step ST29). If it is determined that they intersect, the intersection of the straight line connecting the two points and the line segment B is determined. Is obtained and stored in the memory 32 (step ST30). Thereafter, the sequence returns to step ST26, and the same processing is repeated thereafter. Even when it is determined in step ST29 that the straight line connecting the two points does not intersect with the line segment B, the sequence returns to step ST26.

  During the repeated execution of these steps ST26 to ST30, if it is determined in step ST27 that the elevation list cannot be acquired, it is recognized that the processing for one contour line has been completed, and the sequence returns to step ST24. The process described above is repeated. If it is determined in step ST25 that the elevation list cannot be acquired during the repeated execution of steps ST24 to ST30, it is recognized that the processing for all the elevation lists is completed, and the sequence proceeds to step ST31. At this time, the three-dimensional coordinates (x, y, h) of the intersections of one line segment orthogonal to the half line A and all the contour lines are stored in the memory 32.

  In step ST31, rearrangement of intersections is performed. The rearranged intersection points are stored in the memory 32 (step ST32). Next, the line segment B is moved away by a certain distance (step ST42). That is, the CPU 31 calculates a line segment (line segment B ′ in FIG. 16) obtained by moving the line segment B by a certain distance. Next, the count value i is incremented (+1) (step ST43). Thereafter, the sequence returns to step ST41, and the above-described processing is repeated. If it is determined in step ST41 that the count value i has exceeded the set value during the repeated execution of steps ST41 to ST43, all the line segments orthogonal to the half line A are set in advance. It is recognized that the process has been completed, and the process ends. Through the above processing, a group of intersections between a plurality of line segments orthogonal to the half line A and contour lines representing mountains are acquired.

  Thereafter, for each of a plurality of line segments orthogonal to the half line A, a plurality of mountains are drawn by connecting the intersection group, and these are combined and displayed. At the time of this composition, a part where a distant mountain overlaps with a nearby mountain is synthesized so that a part of the distant mountain is hidden behind the nearby mountain. Therefore, for a portion where a distant mountain is hidden by a nearby mountain, it is possible to omit the calculation for drawing the distant mountain, and if it is omitted, the processing speed can be increased.

  As described above, according to the navigation system according to the second embodiment of the present invention, the intersections between the contour lines and the plurality of line segments orthogonal to the straight line A starting from the current position of the host vehicle and directed in the traveling direction. Since the mountain is drawn based on the obtained intersection, the change in the shape of the mountain due to the movement of the vehicle can be suppressed, and the mountain having a shape closer to the actual background can be drawn. it can.

  In the navigation system according to the second embodiment, the color of the mountain drawn for each of the plurality of line segments orthogonal to the half line A can be configured differently. For example, a nearby mountain can be drawn with a dark color, and a far mountain can be drawn with a light color. According to this configuration, the mountain drawn on the occupant viewpoint map can be given a sense of perspective, so that it is possible to draw a mountain closer to the actual background.

Embodiment 3 FIG.
The navigation system according to Embodiment 3 of the present invention is the same as the navigation system according to Embodiment 2, but the intervals between the plurality of line segments orthogonal to the half line A are narrowed within a predetermined distance from the current position of the host vehicle. In this case, it is widened above a predetermined distance. The functional configuration and hardware configuration of the navigation system according to the third embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

  The operation of the navigation system according to Embodiment 3 of the present invention will be described. FIG. 19 is a diagram for explaining the mountain drawing process of the navigation system, and shows a state in which a plurality of mountains exist in the traveling direction (gaze direction) of the own vehicle with the current position of the own vehicle as a reference point. ing. In this navigation system, within a predetermined distance (indicated by a broken line in FIG. 19) from the current position of the own vehicle, a line segment perpendicular to the half line A extending in the traveling direction starting from the current position (reference point) of the own vehicle. A plurality of narrowly spaced line segments B (1), B (2),..., B (m) are obtained, and a plurality of widely spaced line segments B (n) at a predetermined distance or more from the current position of the host vehicle. ) Is required. And the intersection group of these some line segments and a contour line is acquired.

  Thereafter, for each of a plurality of line segments orthogonal to the half line A, a plurality of mountains are drawn by connecting the intersection group, and these are combined and displayed. At the time of this composition, a portion where a distant mountain overlaps with a nearby mountain is displayed so that a part of the distant mountain is hidden behind the nearby mountain.

  As described above, according to the navigation system of the third embodiment of the present invention, within a predetermined distance from the current position of the host vehicle, the intervals between the plurality of line segments orthogonal to the half line A are narrowed to Since the interval between the line segments orthogonal to the half-line A is widened, the nearby mountains are drawn in detail, but the far mountains are drawn roughly. Therefore, the processing time for drawing a distant mountain can be shortened, and the processing speed of the navigation system can be improved as a whole.

Embodiment 4 FIG.
In the navigation system according to Embodiment 4 of the present invention, in the navigation system according to Embodiment 2, the intervals of a plurality of line segments orthogonal to the half line A are increased as the distance from the current position of the host vehicle increases. It is a thing. The functional configuration and hardware configuration of the navigation system according to the fourth embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

The operation of the navigation system according to Embodiment 4 of the present invention will be described. FIG. 20 is a diagram for explaining the mountain drawing process of the navigation system, and shows a state in which a plurality of mountains exist in the traveling direction of the own vehicle (the direction of the gaze destination) with the current position of the own vehicle as a reference point. ing. In this navigation system, as a line segment orthogonal to the half line A that extends in the traveling direction from the current position (reference point) of the own vehicle, a plurality of line segments that are spread at equal intervals as the distance from the current position of the own vehicle increases. B (1), B (2), B (3),..., B (n) are obtained. The distance to each line segment B (1), B (2), B (3),..., B (n) can be obtained according to the following equation (1).
Distance from current position of own vehicle to line segment B (1) × r ^n-1 (1)
Here, r is a predetermined common ratio, and n is the number of the line segment B given in order from the current position of the vehicle.

  Next, an intersection group of the plurality of line segments and contour lines obtained as described above is acquired. Thereafter, for each of a plurality of line segments orthogonal to the half line A, a plurality of mountains are drawn by connecting the intersection group, and these are combined and displayed. At the time of this composition, a portion where a distant mountain overlaps with a nearby mountain is displayed so that a part of the distant mountain is hidden behind the nearby mountain.

  As described above, the navigation system according to Embodiment 4 of the present invention is configured to draw a mountain based on a plurality of line segments that are spread at equal intervals as the vehicle is moved away from the current position. As a result, the nearby mountains are drawn in detail, but they are roughly drawn as they become far away. Therefore, the processing time for drawing a distant mountain can be shortened, and the processing speed of the navigation system can be improved as a whole.

Embodiment 5. FIG.
A navigation system according to Embodiment 5 of the present invention is such that in the navigation system according to Embodiment 2, a line segment passing through the top of a mountain is used as a plurality of line segments orthogonal to the half line A. . The functional configuration and hardware configuration of the navigation system according to the fourth embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

  The operation of the navigation system according to Embodiment 5 of the present invention will be described. FIG. 21 is a diagram for explaining the mountain drawing process of this navigation system, and shows a state in which a plurality of mountains exist in the traveling direction (gaze direction) of the own vehicle with the current position of the own vehicle as a reference point. ing. In this navigation system, a line segment that passes through the mountain apex of the mountain m1 in the order that is closer to the current position of the vehicle, as a line segment that is orthogonal to the half line A that starts from the current position (reference point) of the vehicle and extends in the traveling direction. B (1), a line segment B (2) passing through the peak of the mountain m2,..., A line segment B (n) passing through the peak of the mountain mn is obtained.

  Next, an intersection group of the plurality of line segments and contour lines obtained as described above is acquired. Thereafter, for each of a plurality of line segments orthogonal to the half line A, a plurality of mountains are drawn by connecting the intersection group and the mountain vertices, and these are combined and displayed. At the time of this composition, a portion where a distant mountain overlaps with a nearby mountain is displayed so that a part of the distant mountain is hidden behind the nearby mountain.

  As described above, according to the navigation system of the fifth embodiment of the present invention, the shape including the summit based on the plurality of line segments passing through the top of the mountain existing in the traveling direction of the current position of the host vehicle. 14 is drawn, for example, a mountain having a peak is drawn instead of a flat mountain having no peak as shown in FIG. Therefore, it is possible to draw a mountain having a shape closer to the actual background. In addition, by obtaining the intersection of the “line segment passing the summit” and the contour line, the intersection point with the contour line is the same regardless of the distance from the vehicle position to the mountain, so if the traveling direction is the same, A mountain with the same shape can always be drawn.

Embodiment 6 FIG.
A navigation system according to Embodiment 6 of the present invention is the same as the navigation system according to Embodiment 1, but instead of a straight line orthogonal to the half line A, a circle or arc centered on the current position (reference point) of the host vehicle. Is used. The functional configuration and hardware configuration of the navigation system according to the sixth embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

  An outline of the operation of the navigation system according to the sixth embodiment of the present invention will be described with reference to an explanatory diagram shown in FIG. 22 focusing on mountain drawing processing executed by the mountain drawing program 23. In the mountain drawing process, first, a reference point is acquired by the same method as in the first embodiment. A circle or arc is then determined. That is, as shown in FIG. 22, a circle or an arc having a predetermined distance as a radius around the current position (reference point) of the host vehicle is obtained. Note that the circle or arc need not be a strict circle or arc, and may be, for example, an ellipse or an elliptic arc. The curve referred to in the present invention includes an ellipse or an elliptic arc in addition to a circle and an arc. Next, an intersection between the circle or arc and the contour line is obtained, and a mountain is drawn based on the obtained intersection. The following processing is the same as in the first embodiment.

  As described above, according to the navigation system according to the sixth embodiment of the present invention, the mountains that are equidistant from the occupant are drawn on the plane, so that the mountains closer to the actual background are drawn. Can do.

Embodiment 7 FIG.
The navigation system according to the seventh embodiment of the present invention displays not only the mountain existing at the predetermined radial position from the current position of the host vehicle but also the mountain existing at the other radial position. It is a thing. The functional configuration and hardware configuration of the navigation system according to the seventh embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

  Next, the operation of the navigation system according to Embodiment 7 of the present invention will be described. FIG. 23 is a diagram for explaining the mountain drawing process of the navigation system, and shows a state where a mountain exists in the traveling direction of the own vehicle with the current position of the own vehicle as a reference point. In this navigation system, a circle or arc D1 existing at a position separated by a first distance in the radial direction around the current position (reference point) of the host vehicle and a circle or arc existing at a position separated by a second distance in the radial direction. D2 is determined. Then, an intersection group c1 between the mountain and the circle or the arc D1 and an intersection group c2 between the mountain and the circle or the arc D2 are acquired. Thereafter, a mountain is drawn using the intersection group c1. Next, a mountain is drawn using the intersection group c2. Next, these two peaks are combined and displayed.

  In the seventh embodiment, an example in which a mountain is drawn using a circle or arc D1 and a circle or arc D2 has been described. However, the number of circles or arcs is not limited to two, and may be three or more. it can. By increasing the number of circles or arcs, it is possible to draw a mountain closer to the actual landscape.

  Next, details of the mountain drawing process performed by the mountain drawing program for realizing the above-described operation will be described with reference to the flowchart shown in FIG. In addition, the same code | symbol is attached | subjected to the step which performs the process same as the mountain drawing process in the navigation system which concerns on Embodiment 2 shown in the flowchart of FIG. 18, and description is simplified.

  In the mountain drawing process, first, the current position of the host vehicle is input (step ST20). Next, a circle or arc having a predetermined radius centered on the current position of the host vehicle is obtained (step ST50). Specifically, the CPU 31 obtains a circle or arc D1 whose center is the reference point determined in step ST20 and whose radius is a predetermined distance. Next, the count value i of the counter is initialized to zero (step ST40). Next, it is checked whether or not the count value i exceeds a set value (step ST41).

  Next, acquisition of one elevation list is attempted (step ST24), and it is checked whether or not the elevation list has been acquired (step ST25). Here, if it is determined that the altitude list has been acquired, then it is attempted to acquire two adjacent points from the altitude list (step ST26), and it is checked whether two points have been acquired (step ST27). If it is determined that two points have been acquired, a linear equation connecting these two points is obtained (step ST28).

  Next, it is checked whether or not the straight line connecting the two points obtained in step ST28 intersects with the circle or arc (step ST51). If it is determined that they intersect, the intersection of the straight line connecting the two points with the circle or arc is determined. Is obtained and stored in the memory 32 (step ST30). Thereafter, the sequence returns to step ST26, and the same processing is repeated thereafter. Even when it is determined in step ST29 that the straight line connecting the two points does not intersect with the circle or arc, the sequence returns to step ST26.

  During the repeated execution of these steps ST26 to ST30, if it is determined in step ST27 that the elevation list cannot be acquired, it is recognized that the processing for one contour line has been completed, and the sequence returns to step ST24. The process described above is repeated. Then, during the repeated execution of steps ST24 to ST30, if it is determined in step ST25 that the elevation list cannot be acquired, it is recognized that the processing for all the elevation lists has been completed, and the sequence proceeds to step ST52. At this time, the three-dimensional coordinates (x, y, h) of the intersections of one line segment orthogonal to the half line A and all the contour lines are stored in the memory 32.

  In step ST52, it is checked whether or not an intersection exists. Here, when it is determined that there are intersections, the intersections are rearranged (step ST31). The rearranged intersection points are stored in the memory 32 (step ST32). Next, the radius of the circle or arc is extended by a predetermined distance (step ST53). That is, the CPU 31 calculates a circle or arc obtained by moving the circle or arc by a certain distance (circle or arc D2 in FIG. 16). If it is determined in step ST52 that there is no intersection, the processes in steps ST31 to ST53 are skipped. Next, the count value i is incremented (+1) (step ST43). Thereafter, the sequence returns to step ST41, and the above-described processing is repeated.

  If it is determined in step ST41 that the count value i has exceeded the set value during the repeated execution of steps ST41 to ST43, the processing for all preset circles or arcs has been completed. And the process ends. With the above processing, a group of intersections between a plurality of circles or arcs and contour lines representing mountains is acquired. Thereafter, for each of a plurality of line segments orthogonal to the half line A, a plurality of mountains are drawn by connecting the intersection group, and these are combined and displayed. At the time of this composition, a portion where a distant mountain overlaps with a nearby mountain is displayed so that a part of the distant mountain is hidden behind the nearby mountain.

  As described above, according to the navigation system of the seventh embodiment of the present invention, intersection points between a plurality of circles or arcs centered on the current position of the vehicle and contour lines are obtained, and mountains are calculated based on the obtained intersection points. Thus, it is possible to draw a mountain having a shape closer to the actual background while suppressing a change in the shape of the mountain due to the movement of the host vehicle.

  In the navigation system according to the second embodiment, the color of the mountain drawn for each circle or arc can be different. For example, a nearby mountain can be drawn with a dark color, and a far mountain can be drawn with a light color. According to this configuration, the mountain drawn on the occupant viewpoint map can be given a sense of perspective, so that it is possible to draw a mountain closer to the actual background.

  As in the navigation system according to the fifth embodiment, a circle or arc passing through the top of the mountain can be used as the circle or arc for obtaining the intersection with the contour line. In this case, the same operation and effect as the navigation system according to the fifth embodiment are obtained.

Embodiment 8 FIG.
The navigation system according to Embodiment 8 of the present invention is the navigation system according to Embodiment 7, wherein the distance between the circles or the arcs is reduced within a predetermined distance from the current position of the host vehicle, and is increased above the predetermined distance. It is what you do. The functional configuration and hardware configuration of the navigation system according to the eighth embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

  The operation of the navigation system according to Embodiment 8 of the present invention will be described. FIG. 25 is a diagram for explaining the mountain drawing process of the navigation system, and shows a state where a mountain exists in the traveling direction of the own vehicle with the current position of the own vehicle as a reference point. In this navigation system, a plurality of narrow circles or arcs are obtained when the radius is within a predetermined distance with the current position (reference point) of the host vehicle as the center, and a plurality of wide intervals are obtained at a predetermined distance or more from the current position of the host vehicle. Circle or arc is required. And the intersection group of these some circle | round | yen or circular arc and a contour line is acquired.

  Thereafter, for each of a plurality of circles or arcs, a plurality of mountains are drawn by connecting the intersection group, and these are combined and displayed. At the time of this composition, a portion where a distant mountain overlaps with a nearby mountain is displayed so that a part of the distant mountain is hidden behind the nearby mountain.

  As described above, according to the navigation system according to the eighth embodiment of the present invention, the interval between the plurality of circles or arcs is narrowed within a predetermined distance from the current position of the host vehicle, and above the predetermined distance, Since the intervals between the circles or the arcs are widened, the nearby mountains are drawn in detail, but the far mountains are drawn roughly. Therefore, the processing time for drawing a distant mountain can be shortened, and the processing speed of the navigation system can be improved as a whole.

Embodiment 9 FIG.
A navigation system according to Embodiment 9 of the present invention is the navigation system according to Embodiment 7, in which the intervals between a plurality of circles or arcs are increased as the distance from the current position of the host vehicle increases. . The functional configuration and hardware configuration of the navigation system according to the ninth embodiment are the same as those of the navigation system according to the first embodiment shown in FIGS.

The operation of the navigation system according to Embodiment 4 of the present invention will be described. FIG. 26 is a diagram for explaining the mountain drawing process of the navigation system, and shows a state where a mountain exists in the traveling direction of the own vehicle with the current position of the own vehicle as a reference point. In this navigation system, a plurality of circles or arcs D1, D2, D3, and D4 that expand as equal circles or arcs as they move away from the current position of the host vehicle as a circle or arc centered on the current position (reference point) of the host vehicle. Is required. The distance from the reference point to each circle or arc D1, D2, D3, and D4 can be obtained according to the following equation (2).
Radius of circle D1 × r ^n-1 (2)
Here, r is a predetermined public ratio, and n is the number of a circle or an arc that is added in order from the current position of the vehicle.

  Next, a group of intersections between the plurality of circles or arcs obtained as described above and the contour lines are acquired. Thereafter, for each of a plurality of circles or arcs, a plurality of mountains are drawn by connecting the intersection group, and these are combined and displayed. At the time of this composition, a portion where a distant mountain overlaps with a nearby mountain is displayed so that a part of the distant mountain is hidden behind the nearby mountain.

  As described above, according to the navigation system of the ninth embodiment of the present invention, the mountain is drawn based on a plurality of circles or arcs that spread at equal intervals as the vehicle moves away from the current position. Since it is configured, nearby mountains are drawn in detail, but are drawn roughly as they become distant mountains. Therefore, the processing time for drawing a distant mountain can be shortened, and the processing speed of the navigation system can be improved as a whole.

It is a block diagram which shows the functional structure of the navigation system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the detailed hardware constitutions of the navigation system which concerns on Embodiment 1 of this invention. It is a figure which shows the storage format of the altitude data used with the navigation system which concerns on Embodiment 1 of this invention. It is a flowchart which shows the operation | movement of the outline of the navigation system which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the method of calculating | requiring the intersection of the contour line and line segment performed by the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a figure which shows the intersection calculated | required in the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a figure which shows a mode that the intersection data calculated | required by the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention are stored in memory. It is a figure for demonstrating the order which draws a mountain in the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a figure for demonstrating rearrangement of the intersection performed in the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a figure which shows a mode that the intersection data after rearrangement of an intersection are stored in a memory in the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the process which correct | amends the altitude of the end point of the mountain performed in the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is the figure which looked at the mountain drawn in the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention from the side of the advancing direction of the own vehicle. It is a figure which shows the mountain displayed on a screen in the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a flowchart which shows the detail of the mountain drawing process in the navigation system which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 2 of this invention. It is a figure for demonstrating the order which draws a mountain in the mountain drawing process performed with the navigation system which concerns on Embodiment 2 of this invention. It is a flowchart which shows the detail of the mountain drawing process performed with the navigation system which concerns on Embodiment 2 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 3 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 4 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 5 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 6 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 7 of this invention. It is a flowchart which shows the detail of the mountain drawing process performed with the navigation system which concerns on Embodiment 7 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 8 of this invention. It is a figure for demonstrating the mountain drawing process performed with the navigation system which concerns on Embodiment 9 of this invention.

Explanation of symbols

1 input device, 2 storage device, 3 control device, 4 display device, 11 GPS sensor, 12 gyro sensor, 13 vehicle speed sensor, 21 external storage device, 22 car navigation program, 23 mountain drawing program, 24 map data, 25 operating system (OS), 31 CPU, 32 memory, 33 display control device, 41 display device.

Claims (14)

A display device for displaying a map;
A navigation system comprising: a control device that draws a mountain on an occupant viewpoint map that is a landscape in a traveling direction drawn from the viewpoint of a vehicle occupant and displays the mountain on the display device. An input device for inputting a reference point indicating the position of the viewpoint on the map and a traveling direction;
A storage device for storing map data including altitude data,
The control device
Map data including a reference point input from the input device is acquired from the storage device, and a mountain existing in the traveling direction input from the input device is drawn based on elevation data included in the acquired map data. Mountain drawing data creation means for creating mountain drawing data for
A display control device that draws a mountain on the occupant viewpoint map created based on the map data acquired from the storage device and displays the mountain on the display device based on the mountain drawing data created by the mountain drawing data creation means; The navigation system according to claim 1. Mountain drawing data creation means
An intersection point between a line having a predetermined relationship with the reference point input from the input device and a contour line represented by the elevation data included in the map data acquired from the storage device is calculated, and the elevation of the calculated intersection point is calculated. 3. The navigation system according to claim 2, wherein mountain drawing data for drawing a two-dimensional mountain obtained by tying is created.   4. The navigation system according to claim 3, wherein the line having the predetermined relationship is a straight line that intersects the traveling direction at a point that is separated from the reference point by a predetermined distance in the traveling direction. A straight line that intersects the traveling direction intersects the traveling direction at a point further away from the first straight line that intersects the traveling direction at a point that is separated from the reference point by a predetermined distance in the traveling direction. 2 straight lines,
Mountain drawing data creation means
A second 2 obtained by connecting the first two-dimensional mountain obtained by connecting the elevations of the intersections of the first straight line and the contour line and the elevations of the intersections of the second straight line and the contour line. 5. The navigation system according to claim 4, wherein mountain drawing data is created by synthesizing the three-dimensional mountain. A straight line that intersects the traveling direction intersects a plurality of straight lines that intersect the traveling direction at a predetermined distance within a predetermined distance from the reference point, and intersects the traveling direction at a distance wider than the predetermined distance at the predetermined distance or more. A plurality of straight lines to be
Mountain drawing data creation means
The mountain drawing data is created by synthesizing a plurality of two-dimensional mountains obtained by connecting the elevations of intersections between each of the plurality of straight lines intersecting the traveling direction and the contour lines for each straight line. 4. The navigation system according to 4. The straight line intersecting the traveling direction includes a plurality of straight lines arranged so as to spread at equal intervals from the reference point toward the traveling direction,
Mountain drawing data creation means
Generating mountain drawing data for combining and drawing a plurality of two-dimensional mountains obtained by connecting the elevations of intersections between each of the plurality of straight lines intersecting the traveling direction and contour lines for each straight line; The navigation system according to claim 4.   4. The navigation system according to claim 3, wherein the line having the predetermined relationship is a straight line that passes through the summit represented by the altitude data included in the map data acquired from the storage device and intersects the traveling direction.   4. The navigation system according to claim 3, wherein the line having the predetermined relationship is a curve that intersects the traveling direction at a point separated from the reference point by a predetermined distance. A curve that intersects the traveling direction includes a first curve that intersects the traveling direction at a point away from the reference point by a predetermined distance, and a second curve that intersects the traveling direction at a point further away from the predetermined distance. Including
Mountain drawing data creation means
A second 2 obtained by connecting the first two-dimensional mountain obtained by connecting the elevations of the intersections of the first curve and the contour line and the elevations of the intersections of the second curve and the contour line. The navigation system according to claim 9, wherein the mountain drawing data is created by combining the three-dimensional mountain. The curves intersecting the traveling direction include a plurality of curves arranged at a predetermined interval within a predetermined distance from a reference point and a plurality of curves arranged at an interval larger than the predetermined interval at the predetermined distance or more.
Mountain drawing data creation means
10. The navigation system according to claim 9, wherein mountain drawing data is created by synthesizing a plurality of two-dimensional mountains obtained by connecting the altitudes of intersections between the plurality of curves and contour lines for each curve. . The curve that intersects the direction of travel includes a plurality of curves that are arranged so as to spread at equal intervals from the reference point toward the direction of travel,
Mountain drawing data creation means
10. The navigation system according to claim 9, wherein mountain drawing data is created by synthesizing a plurality of two-dimensional mountains obtained by connecting the altitudes of intersections between the plurality of curves and contour lines for each curve. .   4. The navigation system according to claim 3, wherein the line having the predetermined relationship is a curve that passes through the summit represented by the altitude data included in the map data acquired from the storage device and intersects the traveling direction. Mountain drawing data creation means
11. The navigation system according to claim 5, wherein mountain drawing data for drawing the first two-dimensional mountain and the second two-dimensional mountain with different colors is created.

Images