JP4740651B2 - Navigation device - Google Patents

Description

  The present invention relates to a navigation device that displays a map and guides a vehicle to a set destination.

  2. Description of the Related Art A navigation device that displays a route number of a road through which a guidance route passes when a guidance route to a destination is displayed on a map is known (Patent Document 1).

Japanese Patent Laid-Open No. 2003-344058

  In the route number display method by the navigation device disclosed in Patent Document 1, when a guide route passes between roads having different route numbers, the route number of the currently traveling road and the route of the next road to be followed Since it is difficult to distinguish from the number, it may be difficult for the user to know which route number to go to next.

In the navigation device according to the first aspect of the present invention, based on the map data, the map display means for displaying a map including the guidance intersection to be bent on the set recommended route, and information on each connection road connected to the guidance intersection are displayed. Information display means, and the information display means displays information on the escape route that escapes from the guidance intersection according to the recommended route among the connection roads in a predetermined first size, and to the guidance intersection of the connection roads Is displayed in a predetermined second size that is smaller than the first size .
According to a second aspect of the present invention, in the navigation device of the first aspect, the information display means is information relating to a road that does not correspond to either an escape road that escapes from the guidance intersection according to a recommended route or an approach road to the guidance intersection. Is displayed in the second size .
According to a third aspect of the present invention, in the navigation device of the first or second aspect , the information includes at least one of a route number, a road name, or a destination name of each connection road. .
According to a fourth aspect of the present invention, in the navigation device according to any one of the first to third aspects, distance determining means for determining whether or not a distance to the next guidance intersection is within a predetermined distance, a distance Summarizing map creating means for creating a summary map by simplifying the road shape within a predetermined summary range around the guidance intersection when the judging means determines that the distance to the next guidance intersection is within a predetermined distance. Further, the map display means displays the summary map created by the summary map creation means as the above map.

  According to the present invention, it is possible to display the route number to which the next route should be advanced so as to be easily understood by the user.

  A configuration of a navigation apparatus according to an embodiment of the present invention is shown in FIG. This navigation device is used by being mounted on a vehicle, searches for a recommended route to a set destination, and guides the user who is the driver of the vehicle according to the recommended route, thereby moving the vehicle to the destination. I will guide you through. At that time, when the vehicle approaches the intersection where the vehicle should bend on the recommended route (hereinafter referred to as “guided intersection”), a map that summarizes the normal map by simplifying the road shape around the guided intersection based on the normal map (Hereinafter referred to as a summary map). The direction to turn on this summary map is displayed as an enlarged view of the intersection so that the user can understand the traveling direction of the vehicle at a glance. A navigation device 1 shown in FIG. 1 includes a control circuit 11, a ROM 12, a RAM 13, a current location detection device 14, an image memory 15, a display monitor 16, an input device 17, and a disk drive 18. The disc drive 18 is loaded with a DVD-ROM 19 in which map data is recorded.

  The control circuit 11 includes a microprocessor and its peripheral circuits, and performs various processes and controls by executing a control program stored in the ROM 12 using the RAM 13 as a work area. By the processing executed in the control circuit 11, for example, a recommended route to the destination is searched based on the map data recorded on the DVD-ROM 19. In addition, as will be described later, a summary map around the guidance intersection is created and displayed on the display monitor 16 as an enlarged view of the intersection.

  The current location detection device 14 is a device that detects the current location of the host vehicle. For example, a vibration gyro 14a that detects the traveling direction of the host vehicle, a vehicle speed sensor 14b that detects a vehicle speed, and a GPS sensor that detects a GPS signal from a GPS satellite. 14c and the like. The navigation device 1 can determine a route search start point when searching for a recommended route based on the current location of the host vehicle detected by the current location detection device 14.

  The image memory 15 temporarily stores image data to be displayed on the display monitor 16. This image data includes road map drawing data for displaying a summary map image, various graphic data, and the like, and is created by the control circuit 11 based on the map data recorded on the DVD-ROM 19. Using the image data stored in the image memory 15, various images such as a normal map and an enlarged intersection view are displayed on the display monitor 16.

  The input device 17 has various input switches for the user to set a destination and the like, which is realized by an operation panel, a remote controller, or the like. The user operates the input device 17 in accordance with a screen instruction displayed on the display monitor 16 to set a destination by designating a place name, a position on the map, a facility name, etc., and search for a route to the destination. The navigation device 1 can be started.

  The disk drive 18 reads map data for displaying a normal map on the display monitor 16 and creating a summary map near the guidance intersection from the loaded DVD-ROM 19. Although an example using a DVD-ROM is described here, the map data may be read from a recording medium other than the DVD-ROM, such as a CD-ROM or a hard disk. This map data includes route calculation data used to calculate the recommended route, route guidance data used to guide the vehicle to the destination according to the recommended route, such as an intersection name and a road name, and a road representing the road This includes data, background data representing map shapes other than roads, such as coastlines, rivers, railways, and various facilities (landmarks) on the map.

  In the road data, the smallest unit representing a road section is called a link. That is, each road is composed of a plurality of links set for each predetermined road section. In addition, the length of the road section set by a link differs, and the length of a link is not constant. A point connecting the links is called a node, and each node has position information (coordinate information). Also, a point called a shape interpolation point may be set between nodes in the link. Each shape interpolation point also has position information (coordinate information) like each node. The link shape, that is, the shape of the road is determined based on the position information of the node and the shape interpolation point. In the route calculation data, a value called a link cost for representing the time required for passing the vehicle is set corresponding to each of the links.

  When the destination is set as described above according to the operation of the input device 17 by the user, the route calculation to the set destination is calculated using the current location detected by the current location detection device 14 as a route search start point. Based on the data, a predetermined algorithm is used to obtain a recommended route to the destination. Then, the obtained recommended route is displayed on the map displayed on the display monitor 16 by distinguishing it from other roads by changing its display form, for example, display color. Thereby, the user can recognize on the map which road is set as the route.

  Further, after the recommended route is obtained as described above, when the vehicle approaches a guidance intersection on the recommended route, a summary map near the guidance intersection is created and displayed on the display monitor 16 as an enlarged view of the intersection. . Then, an arrow for indicating the direction in which the vehicle should be bent is superimposed and displayed on the enlarged intersection view. As described above, the vehicle is guided to the destination. A specific method for creating the summary map will be described later.

  An example of the intersection enlarged view displayed in the navigation apparatus 1 of this embodiment is shown in FIG. Here, an example of an enlarged view of the intersection displayed on the display monitor 16 when the vehicle is traveling on the national highway 246, turns right at the guidance intersection ahead and proceeds to the national highway 16 is shown. In this enlarged view of the intersection, the shape of each road near the guidance intersection is represented by a summary map. That is, the shape of each road is simplified from the original one, and is easy for the user to see.

  In the enlarged intersection view of FIG. 2, an arrow 20 indicates the direction in which the vehicle should turn at the guidance intersection, that is, the right turn direction. Such an arrow is referred to as a guide arrow in the following description. Reference numerals 21 to 24 represent route numbers of roads (hereinafter referred to as connection roads) connected to the guidance intersection, and are called route number icons. The route number icons 21 and 22 indicate that the connecting road is the national road 246, and the route number icons 23 and 24 indicate that the connecting road is the national road 16.

  The route number icon 24 is displayed larger than the other route number icons 21, 22 and 23. As described above, in the navigation device 1 according to the present embodiment, among the connection roads displayed in the enlarged intersection view, the road to which the vehicle should proceed next, that is, when the vehicle escapes from the guidance intersection after turning at the guidance intersection. For connection roads (hereinafter referred to as “escape roads”), a route number icon is displayed larger than other connection roads, for example, roads (entrance roads) on which vehicles enter a guidance intersection. By doing in this way, it is displayed so that it may be easy for the user to know which route number the next road number should go to.

  FIG. 3 shows an example of an enlarged intersection view displayed when approaching a guided intersection different from FIG. Here, an example is shown in which the vehicle turns left from National Route 16 and passes once through National Route 20, and then immediately turns right and travels again on National Route 16, where two adjacent guided intersections expand one intersection. It is displayed by the figure. The guidance arrow 25 indicates the direction in which the vehicle should turn at the two guidance intersections. The first guidance intersection represents the left turn direction, and the second guidance intersection represents the right turn direction.

  Thus, when two adjacent guidance intersections are displayed by one intersection enlarged view, the route corresponding to the escape route of the first guidance intersection among the route number icons 26 to 29 of each connection road. Both the number icon 28 and the route number icon 29 corresponding to the escape route of the second guidance intersection are displayed large. By doing so, even in the enlarged view of the intersection as shown in FIG. 3, it is possible to display which route number the next road number should be advanced in such a manner that is easy for the user to understand.

  FIG. 6 shows a flowchart of processing executed in the navigation device 1 when displaying the enlarged intersection view as described above. This flowchart is executed by the control circuit 11 when the vehicle is guided to the destination according to the searched recommended route. In step S10, it is determined whether or not the distance from the current location of the vehicle to the next guidance intersection on the recommended route is within a predetermined distance, for example, within 300 m. When it is within the predetermined distance to the next guidance intersection, the process proceeds to the next step S20.

  In step S20, a map range for creating a summary map, that is, a summary range is set. Here, a predetermined map range around the next guidance intersection is set as the summary range. At this time, if the next guidance intersection is adjacent, the summary range is set so as to include the two guidance intersections. In the next step S30, a summary map creation process is performed for the map within the summary range set in step S20. This creates a summary map that simplifies the shape of the road near the next guidance intersection. The specific contents of the summary map creation process will be described later.

  In step S40, the summary map created in step S30 is displayed on the display monitor 16. Thereby, the summary map of the next guidance intersection is displayed as an intersection enlarged view of the guidance intersection. In the next step S50, a guidance arrow indicating the direction in which the vehicle should turn at the guidance intersection is displayed on the summary map displayed in step S40. Thereby, the guide arrow 20 of FIG. 2 and the guide arrow 25 of FIG. 3 are displayed.

  In step S60, the route number of each connecting road at the next guidance intersection is extracted from the map data. In the next step S70, one of the connecting roads from which the route numbers are extracted in step S60 is selected.

  In step S80, it is determined whether or not the connecting road selected in step S70 is an escape road at the next guidance intersection. If it is determined that the route is an escape route, the process proceeds to step S90, and a large route number icon is displayed for the connected road based on the route number extracted in step S60. The size of the route number icon displayed at this time is set in advance. Thereby, the route number icon 24 of FIG. 2 and the route number icon 28 or 29 of FIG. 3 are displayed. If step S90 is performed, it will progress to step S110.

  On the other hand, if it is determined in step S80 that the road is not an escape road, that is, if it is determined that the road is a connection road other than the escape road such as an approach road, the process proceeds to step S100, and the connection road is extracted in step S60. A small route number icon is displayed based on the route number. Note that the size of the route number icon displayed at this time is also set in advance as in step S90. Thereby, the route number icon 21 in FIG. 2 and the route number icon 26 in FIG. 3 are displayed for the approach route. For other connecting roads, the route number icon 22 or 23 in FIG. 2 and the route number icon 27 in FIG. 3 are displayed. If step S100 is performed, it will progress to step S110.

  In step S110, it is determined whether all connecting roads at the next guidance intersection have already been selected in step S70. If all connected roads have been selected, the process proceeds to step S120. If there is a connection road that has not yet been selected, the process returns to step S70, and one of them is selected in step S70, and then the above-described processing is executed for the connection road. In this way, by executing the process of step S90 or S100 for all the connected roads, either a large or small route number icon is displayed for each connected road.

  By executing the processing up to step S110 described above, an enlarged view of the intersection as shown in FIGS. 2 and 3 is displayed on the display monitor 16. FIG.

  In step S120, it is determined whether or not the vehicle has passed the next guidance intersection, that is, the guidance intersection displayed on the display monitor 16 as shown in FIG. 2 or FIG. 3 by the processing up to step S110. . When it passes, it progresses to the following step S130, and the intersection enlarged view is deleted from the display monitor 16. In addition, when a plurality of guidance intersections are included in the displayed intersection enlarged view, when the last guidance intersection is passed, the process proceeds from step S120 to S130. If step S130 is performed, it will return to step S10 and the above processes will be repeated. As described above, whenever the vehicle approaches the next guidance intersection, an enlarged view of the intersection of the guidance intersection is displayed.

  Next, the contents of the summary map creation process executed in step S30 will be described. In the summary map creation process, a summary map of each route is created by simplifying the road shape of each route by executing a process called a direction quantization process. This direction quantization process will be described below.

  In the direction quantization process, the link of the searched recommended route is divided by a predetermined number of divisions, and then the road shape is simplified. 7 and 8 are detailed explanatory diagrams for explaining the contents of the direction quantization processing. FIG. 7 shows the case where the number of link divisions is 2 (two divisions), and FIG. 8 shows the number of link divisions. For the case of 4 (4 divisions), the contents of each direction quantization process are shown. Hereinafter, description will be given before the case of the two divisions shown in FIG.

  Reference numeral 30 in FIG. 7A illustrates one of the links included in the searched route. For this link 30, as shown in (b), a point 32 on the link 30 that is farthest from the line segment 31 connecting the both end points is selected. The point 32 selected here corresponds to the shape interpolation point described above, and both end points correspond to nodes.

When the point 32 as described above is obtained, next, as shown in (c), line segments 33 and 34 connecting the point 32 and each of the end points of the link 30 are set. The angles formed by the line segments 33 and 34 with respect to the respective reference lines are represented as θ ₁ and θ ₂ . Here, the reference line is a line extending from each end point of the link 30 in a predetermined direction (for example, a true north direction). (C), the angle of the portion sandwiched by the reference line and the line segment 33 from one end point is represented as theta _1. The angle of the portion sandwiched by the reference line and the line segment 34 from the other end point is represented as theta _2.

When the line segments 33 and 34 connecting the point 32 and the both end points of the link 30 are set as described above, the directions of the line segments 33 and 34 are respectively quantized as shown in FIG. . The quantization in the direction here means that the line segments 33 and 34 are rotated around the respective end points so that the aforementioned angles θ ₁ and θ ₂ are respectively integral multiples of preset unit angles. Say. That is, the values of θ ₁ and θ ₂ are corrected by rotating the line segments 33 and 34 so that θ ₁ = m · Δθ and θ ₂ = n · Δθ (n and m are integers), respectively. In the above equation, the values of m and n are set so that the corrected θ ₁ and θ ₂ calculated by this equation are closest to the original values, respectively.

As described above, when the directions of the line segments 33 and 34 are quantized, the angles θ ₁ and θ ₂ between the line segments 33 and 34 and the reference line are corrected in increments of the unit angle Δθ. In FIG. 7D, Δθ = 15 °. Then, the theta ₁ is shows an example in which the angle after correction is set to m = 6 to 90 °, for theta ₂ is the angle of the corrected set to n = 0 to 0 °.

  If the directions of the line segments 33 and 34 are respectively quantized in this way, then the intersection points when the line segments 33 and 34 are respectively extended are obtained. Then, as shown in (d), the lengths of the line segments 33 and 34 are corrected so as to connect the intersections and the end points.

  As described above, the line segments 33 and 34 are obtained, the directions are quantized, and the length is corrected, whereby the direction quantization processing in the case of the division into two for the link 30 is performed. By using these line segments 33 and 34 instead of the link 30, the shape of the link 30 can be simplified. At this time, since the shape of the link 30 is simplified while the positions of both end points of the link 30 are fixed, the position of the adjacent link is not affected. Therefore, by simplifying each link shape of the route using the direction quantization process, the road shape can be easily simplified while maintaining the overall positional relationship of the route.

  Next, the direction quantization process in the case of four divisions will be described. Reference numeral 40 in FIG. 8A exemplifies one of the links included in the searched route, as in FIG. 7A. For this link 40, as shown in (b), first, a point 42a on the link 40 that is farthest from the line segment 41a connecting the both end points is selected. Next, line segments 41b and 41c connecting the point 42a and each end point of the link 40 are set, and points 42b and 42c on the link 40 that are farthest from the line segments 41b and 41c are selected. To do. Note that the points 42a to 42c selected here correspond to the above-described nodes or shape interpolation points as in the case of two divisions.

When the points 42a to 42c as described above are obtained, next, as shown in (c), line segments 43 sequentially connecting the end points of the link 40 and the points 42a to 42c in the same manner as in the case of two divisions. , 44, 45 and 46 are set. The angles formed by the line segments 43 to 46 with respect to the respective reference lines are represented as θ ₃ , θ ₄ , θ ₅ and θ ₆ . The reference line at this time is determined not only for the both end points of the link 40 but also for the first selected point 42a located in the middle of the points 42a to 42c.

When the line segments 43 to 46 are set as described above, the direction of each line segment is quantized as shown in (d). At this time, using the point 42a as a storage point, the line segments 44 and 45 are rotated around the storage point 42a, respectively. The line segments 43 and 46 are rotated around the respective end points as in the case of the two division. Here, an example is shown in which Δθ = 15 ° is set in advance and the angles after correction of θ ₃ to θ ₆ are 60 °, 45 °, 180 °, and 60 °, respectively.

  When the directions of the line segments 43 to 46 are quantized in this way, the intersection point when the line segments 43 and 44 are extended next and the intersection point when the line segments 45 and 46 are extended are obtained. Then, as shown in (d), the lengths of the line segments 43 to 46 are corrected so as to connect each intersection and each end point or storage point 42a.

  As described above, the line segments 43 to 46 are obtained, the directions are quantized, and the length is corrected, whereby the direction quantization processing in the case of the quadruple division for the link 40 is performed. By using these line segments 43 to 46 instead of the link 40, the shape of the link 40 can be simplified. At this time, in addition to the positions of both end points of the link 40, the shape of the link 40 is simplified while the position of the storage point 42a is also fixed. Therefore, it is possible to appropriately simplify the road shape while maintaining the overall positional relationship with respect to a route constituted by links having complicated shapes.

  In addition, although the direction quantization process in the case of 2 divisions and 4 divisions has been described above, the direction quantization process can be executed in the same manner for other division numbers. For example, in the case of 8 divisions, first, as in the case of 4 divisions, one point farthest from the line segment connecting the two end points of the link and two points farthest from the two line segments connecting the point and the two end points, respectively. Select. Thereafter, four points farthest from the four line segments connecting the points obtained by adding both end points to these three points are selected. Eight line segments connecting the total of the seven points selected in this way and both end points in order are obtained, and the direction of eight divisions is obtained by performing quantization and length correction in the direction as described above for these line segments. Quantization processing can be performed.

  The number of divisions in the direction quantization process may be set in advance, or may be determined based on the link shape. For example, when the points farthest from the line segments connecting the end points or the points selected so far are sequentially selected as described above, that is, the processing described in FIGS. 7 and 8B is repeated. When going, the process is repeated until the distance from each line segment to the farthest point becomes a predetermined value or less, and the number of points corresponding to the number of times of processing is sequentially selected. In this way, the number of divisions in the direction quantization process can be determined by the shape of the link.

  In the two-division direction quantization process described with reference to FIG. 7, even if the line segments 33 and 34 are respectively extended after the direction is quantized, there may be no appropriate intersection. That is, when the line segments 33 and 34 after the direction is quantized are parallel, if these line segments are extended, they will be integrated into one line segment connecting both end points of the link 33. , There will be no intersection. In such a case, the shape of the link 30 may be simplified by using a line segment directly connecting the both end points, that is, the line segment 31. In addition, in the case of the 4-division direction quantization process described in FIG. 8 and the direction quantization process with a larger number of divisions, if each line segment is extended after the direction is similarly quantized, there is no appropriate intersection point, A direction quantization process with a smaller number of divisions may be performed.

  By sequentially executing the direction quantization process as described above for all the links of each route, it is possible to simplify the road shape of each route and create a summary map. In addition, you may make it perform the above direction quantization processes for every link row | line | column comprised by connecting a some link instead of a link unit. In this case, the points selected as the point 32 in FIG. 7 and the points 42a to 42c in FIG. 8 include not only the shape interpolation points but also nodes.

  Alternatively, in the summary map creation process, the road shape can be simplified without executing the above-described direction quantization process. Here, a method of simplifying the road shape by approximating each link shape with a curve will be described with reference to FIG.

  FIG. 9A illustrates links 50, 51 and 52 as a part of the links included in the searched route. For these links 50 to 52, first, the link directions quantized at both end points of each link are obtained as shown in (b). Here, the link direction that is closest to the original angle and is an integral multiple of the unit angle is obtained in the same manner as the quantization of the direction of each line segment in the above-described direction quantization process. As a result, a link direction as indicated by an arrow in (b) is obtained for each end point.

  Next, as shown in (c), the curves 53, 54 and 55 connecting the end points are obtained to approximate the shape of each link. At this time, the shapes of the curves 53 to 55 are determined so that the direction of the tangent line near the end point of each curve matches the quantized link direction. As a method for obtaining such a curve, for example, there is a spline approximation using a spline function, but a detailed description thereof is omitted here.

  A summary map can be created by simplifying the road shape by sequentially executing the processing described above for all the links of the recommended route and expressing the road shape using the obtained curve. . At this time, as in the case of the direction quantization process, the shape of each link is simplified while the positions of both end points of each link are fixed. Therefore, also in this case, the road shape can be easily simplified while maintaining the overall positional relationship of the route.

  Further, landmarks indicating positions of various facilities are displayed on the created summary map. However, by simplifying the road shape, the position of the road in the summary map changes from the original map. Therefore, if the landmark is displayed on the summary map with the original position, the positional relationship between the road and the landmark cannot be represented correctly. Therefore, when displaying a landmark on the summary map, it is necessary to correct the position of the landmark. The method will be described below.

  In FIG. 10, an outline of landmark position correction will be described. As shown in FIG. 10A, in the original map before summarization, a delicate positional relationship between the position of the landmark and the road is described. When the summary map creation process as described above is performed on the original map and the landmark position is displayed as it is, a summary map as shown in (b), for example, is obtained.

  In the summary map shown in (b), only the position of the road is changed with respect to the original map shown in (a), so the positional relationship between the original landmark and the road is not maintained. For example, paying attention to a post office near the center of the map, the post office is located on the opposite side of the road in the original map shown in (a) and the summary map shown in (b). Therefore, in order to correct such inconvenience, the position of the landmark is corrected. As a result, as shown in the summary map shown in (c), the positional relationship between the road and the landmark is the position on the original map. Try to approximate the relationship.

  Next, a detailed algorithm for landmark position correction will be described with reference to FIG. In the landmark position correction, as shown in FIG. 11A, a pair list between shape vectors before and after summarization is first created. Here, by performing the processing described above at the time of summarization, the number of constituent points of the shape vector representing the shape of the road changes from the original one. Therefore, when creating a pair list, the directionality between the branch points between the shape vectors related in the pair list must match. That is, a one-to-one correspondence is established for each branch point before and after the summary.

  After the pair list is created in this way, as shown in (b), correction processing for equalizing the norm of each shape vector and the distance between the corresponding branch points is performed. That is, in the original map before summarization, the norm value of the shape vector closest to the landmark and the ratio of the distance from the landmark to each branch point in the road route including the shape vector are measured. With this measurement value, even in the map after summarization, the norm value and the ratio of the distance from the landmark to the branch point are equivalent to the shape vector associated with the above pair list. Calculate the position of the mark. Then, a landmark is displayed at the calculated position.

  In the landmark position correction explained above, the shape and distance of the road changes by converting a normal map into a summary map, so the coordinates of the corresponding landmarks (shops along the road, etc.) are also converted according to the road. There is a need to. Therefore, as a parameter for the position of the landmark before conversion, what percentage of the whole landmark is from one end of the road (link) before conversion, which side of the road, from the road Find how many meters away. Then, the converted landmark position is determined using the three parameters for the corresponding road data after conversion. This will be described using a specific example shown in FIG.

FIG. 12A shows an example of landmark positions on a normal map before summarization. Roads connecting the points A and B, the link 61 between points A and _{A 1,} point _{A 1} and the link 62 between the _{A 2,} the link 63 between the point _{A 2} and _{A 3,} and the point _{A 3} And B, and a landmark 60 exists along the road. The length of each of the links 61 to 64 is 150 m, 200 m, 350 m, and 500 m, and the road connecting the points A and B constituted by these links has a total length, that is, 1200 m. . The landmark 60 is located 200 m from the point A ₃ toward the point B, that is, at a point 900 m from the point A, on the left side of the road. The location of the landmark 60 is 10 m away from the road.

  The three parameters described above are obtained for the landmark positions before summarization. The ratio of the first parameter, that is, the distance from one end (point A) of the road to the total distance is obtained as 900/1200 = 0.75 (75%). The second parameter, that is, which side of the road is located, is determined to be on the left side of the road from point A to point B. The third parameter, that is, the distance from the road is obtained as 10 m.

  FIG. 12B shows an example of landmark positions on the map after summarization. In this summary map, the road connecting the point A and the point B is represented by one link 65 and has a length of 1000 m. When the landmark 60 is displayed on the summary map, the converted position is determined using the three parameters obtained previously. That is, the distance from the point A is obtained as 1000 × 0.75 = 750 m using the first parameter. The second parameter and the third parameter determine the position on the left side of the road (link 65) as viewed from the point A and 10 m away from the road. By displaying the landmark 60 at a position that satisfies these conditions, the position of the landmark 60 is corrected.

  By performing the processing described above, the position of the landmark is corrected in the summary map, and the positional relationship between the road and the landmark can be approximated to the original map before the summary. As a result, the landmark position in the summary map can be made as shown in FIG. 10C with respect to the landmark position of the original map shown in FIG. Thus, the landmark position is displayed on the summary map.

According to the embodiment described above, the following operational effects are obtained.
(1) Based on the map data recorded on the DVD-ROM 19, an enlarged view of the intersection including the next guidance intersection to be bent on the set recommended route is displayed on the display monitor 16 (step S40). The route number of each connection road connected to the next guidance intersection is displayed on this enlarged intersection view (steps S90 and S100). At this time, the route number of the escape route from the next guidance intersection among the connected roads is displayed larger than the route numbers of the other connected roads (step S90). Since it did in this way, it can be displayed in an easy-to-understand manner for the user which route number to go to next.

(2) When displaying the route number of the escape route in step S90, the route number is displayed with a large route number icon having a predetermined size. In step S100, when displaying the route number of the connecting road other than the escape route including the approach route to the next guidance intersection, the route number is displayed with a smaller route number icon having a predetermined size. Since it did in this way, the route number of an escape route can be displayed larger than the route number of other connection roads by simple processing.

(3) It is determined whether or not the distance to the next intersection is within a predetermined distance (step S10), and if it is determined that the distance to the next guidance intersection is within the predetermined distance, step A summary map is created by simplifying the road shape within a predetermined summary range set around the intersection at S20 (step S30). This summary map is displayed on the display monitor 16 as an enlarged intersection view in step S40. Since this is done, it is possible to display an enlarged view of the intersection, which is easy for the user to understand the direction to proceed at the guidance intersection.

  In the embodiment described above, the route number icon indicating the route number has been described as displaying the escape route larger than the other connected roads. However, the present invention can be applied to display of other information as long as it represents information related to the connected road. Examples thereof will be described below with reference to the drawings.

  FIG. 4 shows an example in which the present invention is applied to the display of road names. Here, the road name 71 of the approach road is displayed small, and the road name 72 of the escape road is displayed large. Thus, when displaying a road name, a street name, etc., you may display an escape route larger than another connection road.

  FIG. 5 shows an example in which the present invention is applied when a place name of each connecting road at a guidance intersection is displayed by simulating a destination direction signboard installed on an actual road. Here, the destination names 81 and 82 of the connected roads that are not escape routes are displayed small, and the destination name 83 of the escape route is displayed large. As described above, in the display simulating the destination direction signboard, the destination name of the escape route may be displayed larger than the destination name of other connecting roads.

  The present invention can be applied to display various other information as long as the information about the connection road is displayed, even if the modification is not the one shown in FIGS. 4 and 5 described above.

  In the above embodiment, the application example in the enlarged intersection map using the summary map has been described, but the present invention can also be applied to the enlarged intersection map using a normal map that is not summarized. Furthermore, it may not be an enlarged intersection view. The present invention can be applied to any map as long as a map including a guidance intersection to be bent on the recommended route is displayed and displayed on a connecting road of the map.

  Each embodiment and various modifications described above are merely examples, and the present invention is not limited to these contents as long as the features of the invention are not impaired.

  In the above embodiment, each means is realized by the processing of the control circuit 11. Specifically, the distance determination means is realized in step S10, the summary map creation means in step S30, the map display means in step S40, and the information display means in steps S90 and S100. In addition, the above description is an example to the last, and when interpreting invention, the correspondence of the description matter of said embodiment and the description matter of a claim is not limited or restrained at all.

It is a block diagram which shows the structure of the navigation apparatus by one Embodiment of this invention. It is an example of an intersection enlarged view. It is an example of another intersection enlarged view. It is an example applied to the display of a road name. This is an example applied to a display simulating a destination direction signboard. It is a flowchart performed when displaying an intersection enlarged view. It is a figure for demonstrating the content of the direction quantization process in the case of 2 division utilized when producing a summary map. It is a figure for demonstrating the content of the direction quantization process in the case of 4 divisions similarly. It is a figure for demonstrating the method of simplifying the road shape of each path | route by approximating each link shape with a curve. It is explanatory drawing of the outline | summary of the position correction of a landmark. It is explanatory drawing of the detailed algorithm of the position correction of a landmark. It is a figure which shows the specific example of the position correction of a landmark.

Explanation of symbols

1 Navigation device 11 Control circuit 12 ROM
13 RAM
14 Current location detection device 15 Image memory 16 Display monitor 17 Input device 18 Disk drive 19 DVD-ROM
20, 25 Guide arrows 21, 22, 23, 26, 27 Small route number icons 24, 28, 29 Large route number icons

Claims (4)

Map display means for displaying a map including a guided intersection to be turned on the set recommended route based on the map data;
Comprising information display means for displaying information about each connecting road connected to the guidance intersection,
The information display means displays information on an escape route that escapes from the guidance intersection according to the recommended route in the connection road in a predetermined first size,
A navigation device , wherein information relating to an approach path to the guidance intersection in the connection road is displayed in a predetermined second size smaller than the first size . The navigation device according to claim 1.
The information display means displays , in the second size, information related to a road that does not correspond to either the escape road that escapes from the guidance intersection according to the recommended route or the approach road to the guidance intersection. The navigation apparatus characterized by doing. The navigation device according to claim 1 or 2 ,
The navigation apparatus according to claim 1, wherein the information includes at least one of a route number, a road name, and a destination name of each connection road. The navigation device according to any one of claims 1 to 3 ,
Distance determining means for determining whether or not the distance to the next guidance intersection is within a predetermined distance,
When the distance determination means determines that the distance to the next guidance intersection is within the predetermined distance, the summary map creates a summary map by simplifying the road shape within a predetermined summary range around the guidance intersection And a creation means,
The map display means displays the summary map created by the summary map creation means as the map.

Images