JP2006162534A - Navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a navigation system for indicating the position of a landmark on a summary map in easy-to-understand manner, in matching with the display state of the landmark in the summary map. <P>SOLUTION: The navigation system retrieves the landmark (Step S100), when one of landmarks is designated by voice input from a user during display of the summary map, and executes any one of the display processing of enhancement display processing (Step S130), addition display processing (Step S150), contraction scale change display processing (Step S170) or direction display processing (Step S180), according to the display state in the summary map of the landmark. Accordingly, the navigation system displays the position of the landmark on the summary map in a different display format, according to the display state of the landmark in the summary map. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a navigation device that creates and displays a summary map in which a road map is simplified.

  A method for simplifying a road shape based on map data for representing a map is known. For example, in the apparatus disclosed in Patent Document 1, linearization or orthogonalization is performed on each link representing a road shape in map data, and only landmark information within a range defined by a mask is used. By displaying, the road shape is simplified. An easy-to-see map is provided by displaying the map using the road shape simplified in this way.

JP-A-11-202762

  In the apparatus disclosed in Patent Document 1, since only landmark information within the range specified by the mask is displayed on the summary map, it is displayed that even a landmark existing within the map range is displayed. There may not be. Of course, if the landmark does not exist within the map range, it is not displayed. Therefore, even if the user wants to know the position of a specific landmark, it cannot be easily known depending on the display status of the landmark on the summary map. For this reason, there is a demand for a device that can easily indicate the position of the landmark in accordance with the display status of the landmark on the summary map.

A navigation device according to the invention of claim 1 is a map data storage means for storing map data including information on various landmarks, a summary map creating means for creating a summary map summarizing the map based on the map data, and a summary. Map display control means for displaying the summary map created by the map creation means on the display monitor, search means for searching for the landmark designated by the user based on the map data, and summary of landmarks searched by the search means There is provided a landmark display control means for displaying the landmark in a different display form on the summary map according to the display state on the map.
According to a second aspect of the present invention, in the navigation device of the first aspect, when the searched landmark is already displayed on the summary map, the landmark display control means emphasizes the landmark on the summary map. To display.
According to a third aspect of the present invention, in the navigation device according to the first or second aspect, when the searched landmark is not displayed on the summary map and exists within the range of the summary map, the landmark display control means Is to additionally display the landmark on the summary map.
The invention of claim 4 is the navigation device according to any one of claims 1 to 3, wherein the searched landmark is not displayed on the summary map and does not exist within the range of the summary map. In addition, when the distance from the current location is smaller than a predetermined threshold, the landmark display control means switches the scale of the summary map so that the landmark is included in the map range, and then the landmark is displayed on the summary map. It is what is displayed above.
The invention of claim 5 is the navigation device according to any one of claims 1 to 4, wherein the searched landmark is not displayed on the summary map and does not exist within the range of the summary map. If the distance from the current location is equal to or greater than a predetermined threshold, the landmark display control means displays the direction of the landmark as viewed from the current location on the summary map.
According to a sixth aspect of the present invention, in the navigation device according to any one of the first to fifth aspects of the present invention, the voice recognition for recognizing the content of the voice input from the user and identifying the landmark designated by the user based on the voice content. Means are further provided.
The invention according to claim 7 is the navigation device according to any one of claims 1 to 6, wherein the search means connects to an external content server when the landmark designated by the user cannot be searched based on the map data. The landmark is searched, and the landmark display control means displays the landmark searched by the content server on the summary map.

  According to the present invention, the landmark designated by the user is searched, and the landmark is displayed on the summary map in a different display form according to the display status of the landmark on the summary map. Since it did in this way, according to the display condition of the landmark in a summary map, the position of a landmark can be shown clearly.

-First embodiment-
A configuration of a navigation apparatus according to an embodiment of the present invention is shown in FIG. This navigation device is mounted on a vehicle, and by searching for a recommended route to the set destination and simplifying the road shape etc. based on a normal map around the searched recommended route, A map that summarizes the map (hereinafter referred to as a summary map) is created and displayed. Then, the recommended route is shown on the summary map, and the vehicle is guided to the destination according to the recommended route. 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, a disk drive 18, and a voice input device 20. 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 executing a summary map creation process as will be described later in the control circuit 11, a recommended route is searched for the set destination based on the map data recorded on the DVD-ROM 19, and its surroundings are searched. A summary map is created and displayed on the display monitor 16. Further, when various display processes described later are executed, the display content of the display monitor 16 changes accordingly.

  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. A summary map is displayed on the display monitor 16 using the image data stored in the image memory 15.

  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 according to a screen instruction displayed on the display monitor 16 to set a destination by designating a place name or a position on the map, and to search the navigation apparatus 1 for a route search to the destination. Can be started.

  The disk drive 18 reads map data used to create a summary map 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.

  The voice input device 20 detects voice from a user input through a microphone and recognizes the content of the voice. Then, the control circuit 11 is caused to execute processing corresponding to the detected audio content. For example, when the content of the input voice is “destination setting”, the user is prompted to input the name of a landmark to be set as a destination, and the process shifts to a destination input waiting state.

  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.

  As described above, when the destination is set by the user's operation on the input device 17, the route calculation to the set destination is calculated as route calculation data using the current location detected by the current location detection device 14 as a route search start point. Based on the predetermined algorithm, a recommended route to the destination is obtained. Then, a summary map near the obtained recommended route is created based on the road data and displayed on the display monitor 16. As described above, a summary map with a simplified road shape is displayed on the screen, and the host vehicle is guided to the destination according to the recommended route indicated on the summary map. A specific method for creating the summary map will be described later.

  Furthermore, in the navigation device 1 of the present embodiment, when any landmark is designated by voice input from the user while the summary map is displayed, the position of the landmark can be determined on the summary map. Execute the process. At this time, depending on the display status of the landmarks on the summary map, any one of (1) highlight display processing, (2) additional display processing, (3) scale switching display processing, or (4) direction display processing is displayed. , The landmarks are displayed on the summary map in different display forms. Hereinafter, the contents of these display processes will be described.

(1) Highlight Display Process The highlight display process is a process that is performed when a designated landmark is already displayed on the summary map, and the landmark is highlighted and displayed on the summary map. The state of this highlighting process is shown in FIG. (A) has shown the example of the summary map currently displayed on the display monitor 16 before execution of a highlighting process. In the summary map, a vehicle position mark 21 and a traveling direction indication mark 22 are displayed. When the summary map of (a) is displayed, as shown in (c), it is assumed that the user 100 driving the vehicle designates the landmark “m” by voice input.

  The voice input from the user is detected by the voice input device 20, and the voice content is recognized. As a result, the designation of the landmark “m” is transmitted from the voice input device 20 to the control circuit 11. Then, the control circuit 11 confirms the display status of the landmark in the summary map displayed at that time, and determines which display processing to execute according to the confirmation result.

  In the case of FIG. 2, the landmark “m” designated by the user is already displayed in the summary map of FIG. In such a case, the highlighting process is executed. As a result, the summary map shown in (b) is displayed. In the summary map of (b), the landmark “m” indicated by reference numeral 23 is three-dimensionally displayed so as to stand out from the other portions. Note that the landmark 23 may be made conspicuous by using a highlighting method other than the three-dimensional display, for example, a blinking display method or a display method using a different color. In this way, the position of the designated landmark is shown in an easy-to-understand manner.

(2) Additional display processing The additional display processing is processing that is performed when a designated landmark exists within the range of the summary map but is not displayed on the summary map. In this additional display process, the landmark is added and displayed on the summary map. The contents of this additional display process are shown in FIG. (A) has shown the example of the summary map currently displayed on the display monitor 16 before execution of an additional display process. Similar to FIG. 2A, the vehicle position mark 21 and the traveling direction indication mark 22 are displayed on the summary map. When the summary map of (a) is displayed, it is assumed that the driving user 100 designates the landmark “m” by voice input as shown in (c).

  The voice uttered by the user is detected by the voice input device 20 as described above, and the voice content is recognized. As a result, the designation of the landmark “m” is transmitted from the voice input device 20 to the control circuit 11. Then, the control circuit 11 confirms the display status of the landmark in the summary map displayed at that time, and determines which display processing to execute according to the confirmation result.

  In the case of FIG. 3, the landmark “m” designated by the user is not displayed in the summary map of (a). In such a case, an additional display process is executed, and as shown in the result (b), the designated landmark “m” is additionally displayed on the summary map as indicated by reference numeral 23. At this time, as in the case of the above-described highlighting process, it is preferable that the landmark 23 is highlighted and displayed. In this way, the position of the designated landmark is shown in an easy-to-understand manner.

(3) Scale switching display process The scale switching display process is a process performed when a designated landmark is not displayed on the summary map and does not exist within the range of the summary map. In this scale switching display processing, the scale of the summary map is switched so that the landmark is included in the range of the summary map, and then the landmark is displayed on the summary map. The contents of the scale switching display process are shown in FIG. (A) has shown the example of the summary map currently displayed before execution of the scale switching display process in the navigation apparatus 1. FIG. When the summary map of (a) is displayed, it is assumed that the driving user 100 designates the landmark “T tower” by voice as shown in (c).

  The voice uttered by the user is detected by the voice input device 20 as described above, and the designation of the landmark “T tower” is transmitted from the voice input device 20 to the control circuit 11. Then, the control circuit 11 determines which display processing is to be executed in accordance with the landmark display status on the summary map.

  In the case of FIG. 4, the landmark “T tower” designated by the user is not displayed in the summary map of (a). Further, the position of this “T tower” is not included in the range of the summary map of (a). In such a case, the scale switching display process is executed, and the map scale is switched so that the landmark “T tower” is included in the range of the summary map as shown in FIG. The designated landmark “T tower” is displayed on the summary map as indicated by reference numeral 24. At this time, it is preferable that the landmark 24 is highlighted and displayed as in the case of the highlighting process described above. In this way, the position of the designated landmark is shown in an easy-to-understand manner.

(4) Direction display process The direction display process is a case where the designated landmark is not displayed on the summary map and does not exist within the range of the summary map, as in the scale switching display process described above. Further, it is performed when the distance from the current location to the landmark is farther than a predetermined threshold value. If the landmark cannot be displayed as it is on the summary map even if the scale of the summary map is switched by the scale switching display process, the direction of the landmark as viewed from the current location is summarized by this direction display process. Display above. As a result, the landmark is displayed on the summary map. The contents of this direction display processing are shown in FIG. (A) has shown the example of the summary map currently displayed before execution of the direction display process in the navigation apparatus 1. FIG. When the summary map of (a) is displayed, it is assumed that the driving user 100 designates the landmark “F mountain” by voice as shown in (c).

  The voice content uttered by the user is detected by the voice input device 20 as described above, and the voice input device 20 informs the control circuit 11 that the landmark “F mountain” has been designated by the user. Then, it is determined which display processing is to be executed according to the display state of the landmark on the summary map.

  In the case of FIG. 5, the landmark “F mountain” designated by the user is not displayed in the summary map of (a), and is not included in the map range. Further, the position of “F mountain” is far from the vehicle position, and cannot be displayed even if the scale of the summary map is switched. In such a case, by executing the direction display process, the scale of the summary map is switched as shown in (b), and the direction and distance of the landmark “F mountain” are displayed as indicated by reference numeral 25. Is done.

  Alternatively, instead of displaying the direction and distance of “F mountain” as shown in (b), audio may be output as shown in (d). Alternatively, as shown in (e), the planar summary map may be switched to the bird's-eye summary map, and the mark 26 indicating the position of “F mountain” may be displayed on the bird's-eye summary map. In addition, a mark 27 representing the landmark “T tower” is also displayed on the bird's-eye summary map in (e). In this way, the position of the designated landmark is shown in an easy-to-understand manner.

  FIG. 6 shows a flowchart executed in the control circuit 11 of the navigation device 1 during each display process as described above. This flowchart is executed when a landmark is designated by the voice from the user during the display of the summary map as described above. In step S100, the landmark designated by the voice input from the user is searched based on the map data recorded on the DVD-ROM 19. In this case, in order to improve the voice recognition rate, for example, when a button installed near the steering of the vehicle is pressed, it is recognized that the voice specifying the landmark is input from the user. It may be. In addition, the search accuracy may be improved by performing a fuzzy search such as a partial match or synonym expansion as well as a search that completely matches the voice input.

  In step S110, it is determined whether or not the landmark designated in step S100 has been searched. If it is found, the process proceeds to the next step S120. However, if the search is not performed because the designated landmark is not found in the map data, the flowchart of FIG. 6 is terminated. Note that it is preferable that a message indicating that the landmark designated at this time cannot be searched is output by voice or displayed on the screen to inform the user to that effect.

  In step S120, it is determined whether or not the landmark searched in step S100 is displayed on the currently displayed summary map. If the landmark has already been displayed on the summary map, the process proceeds to step S130 to execute the highlighting process as described above. Thereby, the landmark is highlighted and displayed on the summary map. After step S130 is executed, the flowchart of FIG. 6 ends. On the other hand, if it is determined in step S120 that the landmark is not displayed on the displayed summary map, the process proceeds to step S140.

  In step S140, it is determined whether or not the landmark searched in step S100 is within the display range of the currently displayed summary map. When the landmark exists in the display range, the process proceeds to step S150, and the additional display process as described above is executed. As a result, the landmark is additionally displayed on the summary map. After step S140 is executed, the flowchart of FIG. 6 ends. On the other hand, if it is determined in step S140 that the landmark does not exist within the display range of the displayed summary map, the process proceeds to step S160.

  In step S160, it is determined whether or not the distance between the landmark searched in step S100 and the current location is smaller than a predetermined threshold value. The threshold value at this time is set according to the scale of the summary map that can be displayed by the navigation device 1. If it is determined in step S160 that the distance between the landmark and the current location is smaller than the threshold value, the process proceeds to step S170, and the scale switching display process as described above is executed. Thereby, the scale of the summary map is switched, and the landmark is displayed on the summary map after the scale switching. After step S170 is executed, the flowchart of FIG. 6 is terminated.

  If it is determined in step S160 that the distance between the landmark and the current location is smaller than the threshold value, the process proceeds to step S180. In step S180, the direction display process as described above is executed. Thereby, the direction of the landmark is displayed on the summary map. After step S180 is executed, the flowchart of FIG. 6 is terminated.

  Next, the contents of the summary map creation process executed after the recommended route is searched 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 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 are 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 four-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} , 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 1st Embodiment described above, there exists the following effect.
(1) A landmark designated by the user is searched, and display processing of any one of highlight display processing, additional display processing, scale switching display processing, and direction display processing is performed according to the display status of the landmark on the summary map. By doing so, the landmark was displayed on the summary map in a different display form. Since it did in this way, according to the display condition of the landmark in a summary map, the position of the landmark can be shown clearly.

(2) When the searched landmark is already displayed on the summary map, the landmark is emphasized and displayed on the summary map by executing the highlighting process. Since it did in this way, when the landmark already displayed is designated by the user, it can show the position of the landmark in an easy-to-understand manner by displaying the landmark on the summary map prominently. .

(3) If the searched landmark is not displayed on the summary map and exists within the range of the summary map, the landmark is additionally displayed on the summary map by executing additional display processing. It was decided. Since it did in this way, even when the landmark which is not displayed is designated by the user, the landmark can be additionally displayed on the summary map and the position can be shown in an easy-to-understand manner.

(4) If the searched landmark is not displayed on the summary map and does not exist within the range of the summary map, and if the distance from the current location is smaller than a predetermined threshold, the scale is reduced. By executing the switching display process, the scale of the map is switched so that the landmark is included in the map range, and then the landmark is displayed on the summary map. As a result, even when a landmark that does not exist within the range of the summary map displayed so far is specified by the user, the landmark is additionally displayed on the summary map after switching the scale and its position is displayed. Can be shown in an easy-to-understand manner.

(5) If the searched landmark is not displayed on the summary map and does not exist in the summary map, and if the distance from the current location is greater than or equal to a predetermined threshold, direction display processing As a result, the direction of the landmark viewed from the current location is displayed on the summary map. Thus, even when a landmark far from the current location is designated by the user, the direction of the landmark can be displayed on the summary map so that the position can be easily understood.

-Second Embodiment-
FIG. 13 shows the configuration of a navigation system according to the second embodiment of the present invention. This navigation system includes the navigation apparatus 1 shown in FIG. 1 which is the same as that of the first embodiment, a communication terminal 2, a mobile communication network 3, and a content server 4. The communication terminal 2 is connected to the control circuit 11, and the mobile communication network 3 and the content server 4 are connected.

  As in the first embodiment, the navigation device 1 searches for a recommended route to the set destination, creates and displays a summary map around the recommended route, and is displayed on the summary map. The vehicle is guided to the destination according to the recommended route. When a landmark is designated by voice from the user while the summary map is displayed, the designated landmark is searched based on the map data recorded on the DVD-ROM 19 and the position of the landmark is summarized map. In order to make the user discriminate above, the above-described processing is executed.

  Furthermore, in this embodiment, when the landmark designated by the user is not retrieved from the map data of the DVD-ROM 19, the navigation apparatus 1 makes an inquiry about the landmark to the content server 4. The content server 4 has a POI (Point Of Interest) database, and searches for landmarks based on the POI database in response to an inquiry from the navigation apparatus 1. In the POI database, POI data (data representing the position, name, type, etc. of landmarks) of all parts of the country is recorded and updated to the latest contents constantly or regularly. The landmark search result by the content server 4 is returned to the navigation device 1. The navigation device 1 displays the designated landmark on the summary map using this search result.

  When the navigation apparatus 1 makes an inquiry about the landmark to the content server 4, the communication terminal 2 is wirelessly connected to the mobile communication network 3 under the control of the control circuit 11 in the navigation apparatus 1. As a result, a communication line is established between the navigation device 1 and the content server 4 via the communication terminal 2 and the mobile communication network 3. When the communication terminal 2 and the mobile communication network 3 are wirelessly connected, a radio base station (not shown) is used. The wireless base stations can wirelessly communicate with the communication terminals 2 in a predetermined communication area around the wireless base stations, and are scattered throughout the country. The connection between the navigation device 1 and the communication terminal 2 is not limited to a wired connection such as a cable, but a wireless connection such as an infrared ray may be used. For example, a mobile phone is used as the communication terminal 2.

  FIG. 14 shows a flowchart executed by the control circuit 11 in this embodiment. In this flowchart, processing steps that execute the same contents as those in the flowchart of the first embodiment shown in FIG. 6 have the same step numbers as in FIG. Note that the description of the same step number portion has already been described in FIG.

  In step S101, it is determined whether or not the landmark designated in step S100 has been searched. If a search is made, the process proceeds to step S104, and if not, the process proceeds to step S102. In step S102, the inquiry to the content server 4 is performed as described above. The content server 4 performs a landmark search in response to this inquiry, and returns the search result to the navigation device 1. When a reply from the content server 4 is received, the process proceeds from step S102 to the next step S103.

  In step S103, it is determined whether a landmark has been searched based on the search result received from the content server 4 in step S102. If a search is made, the process proceeds to step S104. If no search is made, the flowchart of FIG. 14 is ended. When ending the flowchart, as in the case of ending in step S110 in FIG. 6, a message indicating that the designated landmark could not be searched is output by voice or displayed on the screen to inform the user to that effect. It is preferable to communicate.

  In step S104, it is determined whether or not the landmark designated in step S100 has been identified in step S100 or S102. If it can be identified, the process proceeds to step S120, and the process described with reference to FIG. 6 is executed for the landmark. On the other hand, when a plurality of landmarks are searched in step S100 or S102, since there are a plurality of landmark candidates to be processed later and cannot be identified as one, the process proceeds to step S105.

  In step S105, one of the searched landmark candidates is selected as a processing target landmark. At this time, the user selects one of a plurality of landmark candidates by making a voice conversation using the voice input device 20 or by selecting the screen by operating the input device 17 from the screen display. If the landmark to be processed is selected, the process proceeds to step S120, and the process described with reference to FIG. 6 is executed for the landmark.

  According to the second embodiment described above, when the landmark designated by the user cannot be searched based on the map data recorded on the DVD-ROM 19, the content installed outside the navigation device 1 is used. The server 4 is connected to search for the landmark. Since it did in this way, even when the newest landmark etc. which are not reflected in map data are designated by the user, the landmark can be displayed on a summary map.

  In each of the above-described embodiments, an example has been described in which the voice input device 20 recognizes the content of voice input from the user and identifies the landmark designated by the user based on the voice content. However, the present invention is not limited to this content, and a landmark to be designated by the user may be input by a method other than voice input, for example, operation of a remote controller or a touch panel.

  In each of the embodiments described above, an example has been described in which the navigation device reads map data from a storage medium such as a DVD-ROM to create a summary map, but the present invention is not limited to this. For example, the present invention can be applied to a communication navigation apparatus that downloads map data from an information distribution center using wireless communication using a mobile phone or the like. In this case, the summary map creation process as described above may be performed in the information distribution center, and the result may be output as a signal from the information distribution center and distributed to the navigation device. That is, the information distribution center includes a device that creates a summary map and a device that outputs the summary map to the outside.

  The present invention is not limited to the above embodiment. Other embodiments conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

1 is a block diagram showing a configuration of a navigation device according to a first embodiment of the present invention. It is a figure which shows the mode of a highlight display process. It is a figure which shows the mode of an additional display process. It is a figure which shows the mode of a scale switching display process. It is a figure which shows the mode of a direction display process. It is a flowchart performed in the case of each display process in 1st Embodiment. 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. It is a block diagram which shows the structure of the navigation system by the 2nd Embodiment of this invention. It is a flowchart performed in the case of each display process in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 2 Communication terminal 3 Mobile communication network 4 Content server 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 Voice input device

Claims (7)

Map data storage means for storing map data including information on various landmarks;
A summary map creating means for creating a summary map summarizing a map based on the map data;
Map display control means for displaying the summary map created by the summary map creation means on a display monitor;
Search means for searching for a landmark designated by the user based on the map data;
A navigation apparatus comprising: landmark display control means for displaying the landmarks retrieved by the retrieval means on the summary map in different display forms according to the display status of the landmarks on the summary map. . The navigation device according to claim 1.
If the searched landmark is already displayed on the summary map,
The landmark display control means emphasizes the landmark and displays it on the summary map. The navigation device according to claim 1 or 2,
If the retrieved landmark is not displayed on the summary map and is within the range of the summary map,
The landmark display control means additionally displays the landmark on the summary map. In the navigation apparatus in any one of Claims 1-3,
When the searched landmark is not displayed on the summary map and does not exist within the range of the summary map, and when the distance from the current location is smaller than a predetermined threshold,
The landmark display control means displays the landmark on the summary map after switching the scale of the summary map so that the landmark is included in the map range. In the navigation apparatus in any one of Claims 1-4,
When the searched landmark is not displayed on the summary map and does not exist within the range of the summary map, and when the distance from the current location is a predetermined threshold value or more,
The said landmark display control means displays the direction which looked at the landmark from the present location on the said summary map, The navigation apparatus characterized by the above-mentioned. In the navigation apparatus in any one of Claims 1-5,
A navigation device further comprising voice recognition means for recognizing a voice content input by a user and identifying a landmark designated by the user based on the voice content. In the navigation apparatus in any one of Claims 1-6,
If the search means could not search the landmark designated by the user based on the map data, connected to an external content server to search for the landmark,
The said landmark display control means displays the landmark searched by the said content server on the said summary map, The navigation apparatus characterized by the above-mentioned.

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