JP2000329567A - Method for displaying landmark, and navigation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for displaying landmarks and a navigation apparatus whereby vehicle position (guide), the intersect state of roads, the state of curves and the like can be made easy to see when guided. SOLUTION: When a vehicle 72 approaches a guide point (intersection) B of a guide road 71, if any of landmarks 75-1, 75-2 and 75-3 displayed in the vicinity of the B projects to the guide road 71, the landmarks 75-1 and 75-2 projecting to the guide road 71 are moved and displayed as shown in (b) and (c). In other words, a driver requires only to detect a rough positional relationship of the guide road 71 and landmarks in the vicinity of the guide point B, not requiring the landmarks to be at a correct position. Therefore, the landmarks 75-i and 75-2 superposed on the guide road 71 are detected and moved to a position where the positional relationship to the guide road 71 is not changed when, the distance between a position of the vehicle 72 and the guide point B becomes not larger than a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle navigation device, and more particularly to a technique for displaying a landmark at the time of route guidance.

[0002]

2. Description of the Related Art An in-vehicle navigation device displays a route (guide route) from a current position of a car to a destination on a map and displays it on a screen to assist a driver in driving. In addition, as a route guidance method, a database (digital map database) created by digitizing roads, place names, buildings, and the like on a map is stored in a recording medium such as a CD-ROM, and based on the database, a user can enter a departure point based on the database. When a destination is input (set), a taxiway is searched and calculated based on a road database held in advance by the device, and the obtained taxiway, self-contained navigation using a gyroscope or a vehicle speed pulse, and GPS are used.
A method of displaying a route on a screen while performing map matching on a vehicle position estimated from radio navigation using FM or FM multiplexing and performing route guidance is known.

[0003] As a guidance display method, a normal map display mode for displaying a map (hereinafter referred to as a normal map) centered on a route in a traveling direction based on a position of a vehicle at a predetermined scale (scale), and a normal map display mode. A destination + normal map display mode in which a map on the destination side is displayed side by side with the above normal map, and highway information + normal in which a service area and a distance to the destination are displayed along with the normal map along with the normal map while driving on an expressway. In addition to the map display mode, when the distance between the host vehicle and the next guidance point is less than a predetermined value, the area near the guidance point (a display area within a predetermined range) is enlarged and displayed together with a normal map + a normal map There are display modes and the like.

On a commercially available map, mountains, rivers, bridges, railway tracks, stations, temples, schools, post offices, and the like are displayed with specific symbols. In a navigation device that needs to be quickly recognized while driving, such a sign is used instead of a structure along a taxiway that serves as a marker for driving (buildings such as a stadium, a tower, a bank, a supermarket, and a gas station). , Restaurants, parking lots, athletic fields,... Etc.) are displayed as landmarks (marks) 95-1, 95-2, 95-3,.

[0005]

However, the landmark display according to the prior art is displayed as it is even when the landmark overlaps the taxiway. Therefore, in the prior art, the vehicle is guided to an intersection or a corner where there are many landmarks. In such a case, a landmark is displayed so as to overlap an intersection or a corner, so that there is a problem that a guide indicating the position of the vehicle is very difficult to understand.

That is, since landmarks have a certain size, if they are displayed according to the coordinate position of a structure along the taxiway, a part of the landmark may protrude into the taxiway. In particular, many landmarks are displayed. At intersections and turns, the protruding portions of the landmarks displayed on the left and right sides of the taxiway are in the way, making it difficult to see the vehicle position guide.

FIG. 9 shows an example in which landmarks protrude (overlap) on a taxiway. In FIG. 9, (a) is an example of a guidance display at an intersection according to the related art.
(B) is an example of a guidance display at a corner according to the related art. Further, reference numerals 91 and 91 ′ denote taxiways and reference numeral 9
Reference numeral 2, 92 'denotes a vehicle position guide indicating the vehicle position.
3, 93 'is the next guide point, and reference numerals 95-1, 95-
2, 92-3, 95'-1, 95'-2, and 95'-3 indicate landmarks.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem in the guidance display of the related art.
It is an object of the present invention to provide a landmark display method and a navigation device that make it easy to see the position of a vehicle (guide), the state of intersection of roads, the state of curves, and the like at the time of guidance.

[0009]

In order to solve the above-mentioned problems, a landmark display method according to a first aspect of the present invention provides a landmark display method in an in-vehicle navigation device, wherein a land protruding and displayed on a taxiway in a section including a next guide point. The method is characterized in that the presence or absence of a mark is detected, and when a landmark protruding on the taxiway is detected, the landmark is moved and displayed so as not to protrude into the taxiway.

According to a second aspect of the present invention, in the landmark display method according to the first aspect, the section including the guide point is enlarged and displayed when a distance between the car and the guide point becomes a predetermined value or less. I do.

According to a third aspect, in the landmark display method according to the first or second aspect, the guide point is an intersection.

According to a fourth aspect of the present invention, there is provided a navigation device for displaying and displaying a route from a current position of a car to a destination on a map. Means for taking in the memory, the overlap detecting means for detecting whether or not the guideway on the map of the taken section and the landmark overlap, and when there is a landmark whose overlap is detected by the overlap detecting means, Map display means for moving the display position of the detected landmark within the section so as not to overlap the taxiway, and then displaying a map of the section.

According to a fifth aspect of the present invention, in the navigation device according to the fourth aspect, a current position obtaining means for obtaining a current position of the vehicle, a current position of the vehicle obtained by the current position obtaining means, and a next guidance. A distance obtaining unit that obtains a distance from the point; and a distance determining unit that compares the distance obtained by the distance obtaining unit with a predetermined value to determine the magnitude of the distance. If the means determines that the distance between the current position of the car and the next guide point is equal to or less than the predetermined value, each of the landmarks overlapping the taxiway overlaps the taxiway while maintaining the positional relationship with the taxiway. It is characterized in that a map of the section is displayed after moving within the section so as not to be distracted.

According to a sixth aspect of the present invention, in the navigation device according to the fourth aspect, the map fetching means enlarges a map of a section including the next guide point to a predetermined size and fetches the map into a memory.

According to a seventh aspect of the present invention, in the navigation device according to the fifth aspect, the map capturing means determines that a distance between the current position of the car and the next guide point is less than a predetermined value by the distance determining means. In addition, a map of a section including the next guide point is enlarged to a predetermined size and stored in a memory.

According to an eighth aspect of the present invention, in the navigation device according to the fourth or fifth aspect, the map display means includes enlarged map display means for enlarging and displaying a map of the section to a predetermined size, and displaying landmarks. After the movement of the position, the map of the section is enlarged and displayed by the enlarged map display means.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Summary of the Invention] In the example of the guidance display at the intersection shown in FIG. 8 (illustration of the landmark display moving method), as shown in FIG. ) When the car (72) approaches B, the landmarks 75-1, 75 displayed near the intersection B
If any of the landmarks 75-2 and 75-3 protrude from the taxiway 71, the landmarks 75-1 and 75 protrude from the taxiway 71 as shown in FIGS.
-2 is moved and displayed. That is, the driver only needs to know the approximate positional relationship between the taxiway 71 and the landmark near the guide point (intersection) B, and the landmark does not have to be located at an accurate position. Landmarks 75-1 and 75- overlapping the taxiway 71 when the distance between the guide point B and the guide point B become equal to or less than a predetermined distance.
2 and moves to a position where the positional relationship with the taxiway 71 does not change (that is, if there is a landmark on the left side of the taxiway 71 like the landmark 75-1, the taxiway 7
1 and move to the left direction to display the landmark 75-2.
If there are landmarks on the right and below the taxiway 71 as shown in FIG.

[Configuration Example of Navigation Apparatus] FIG.
FIG. 1 is a block diagram showing an embodiment of a navigation device to which a landmark display method according to the present invention can be applied.
Relative bearing detection unit 2, vehicle speed detection unit 3, control unit 4, memory 5
, A user interface unit 9, a display unit 10, an input unit 11, a CD-ROM control unit 12, and an FM multiplex reception and processing unit 13.

The absolute position / azimuth detecting unit 1 has an antenna 1a, receives a radio wave from a GPS (Global Positioning System) with the antenna 1a, detects an absolute position (absolute coordinate) and azimuth, and sends it to the control unit 4. .

The relative azimuth detecting unit 2 includes an azimuth detecting device such as a gyro, and sends the detected azimuth to the control unit 4. Further, the vehicle speed detection unit 3 obtains the vehicle side from the rotation pulse obtained as the vehicle travels and sends it to the control unit 4. These detected values (azimuth and speed) are used by the control unit 4 to correct the absolute position and direction obtained from the GPS and determine the current position of the vehicle.

The control unit 4 has a microprocessor configuration including a CPU, a timer, and a CPU peripheral circuit.
U is connected to each of the above-described circuits and the like via a bus line, and the navigation device 1 is controlled by a navigation control program stored in a memory (program storage ROM) 5.
In addition to performing overall control, execution control of each function of the navigation device 100 in response to an input signal from the input unit 10 (for example, execution control of map matching, execution control of route search, landmark display of the present invention) (Eg, execution control of guidance guide map display using maps, routes, landmarks, etc.) based on the method.

The memory 5 is a ROM for storing programs. The ROM 5 for storing programs is a PROM or FR.
An OM (flash ROM) or the like is used to store a control program, a map matching program, a route search program, a guide map display program for displaying maps, routes, landmarks, and the like. Further, icons such as landmarks, menus, graphic patterns, and constants to be displayed on the display unit 10 can be stored in the program storage ROM.

The memory 6 is composed of a DRAM (Dynamic RAM). Under the control of the control unit 4, a required map of the maps stored on the CD-ROM via the CD-ROM control unit 12 and its wide area adjacent area, Import the enlarged map of the next guide point. The memory 7 is an SRAM (Static RAM)
And a high-speed memory such as
0, the control program is fetched from the program storage ROM of the control unit 4, and the map matching program, the route search program, and the guide map are executed in accordance with the control sequence of the control program when the navigation process such as the map matching process and the route search process is executed. Import display programs etc. from time to time.

The memory 8 is a display memory and has a VR
A map for one screen extracted from the DRAM 6 under the control of the control unit 4 (a map for two screens compressed at a predetermined ratio (for example, each half) at the time of displaying an enlarged map).
Also, a bitmap image such as a guideway searched by a route search, a landmark, a name, a menu, or the like is developed.

The user interface unit 9 includes a display unit 10
And an interface connecting the input unit 11 and the control unit 4. The display unit 10 displays a map, a guideway, a name, a menu, and the like stored in the display memory 8.

The input unit 11 is a means for inputting the setting of a departure place and a destination, the selection of a map, and other necessary information by the user. The input unit 11 includes keys and buttons for input, or keys for cursor movement and point (instruction). When these keys and buttons are operated, a status signal is sent to the control unit 4 via the user interface unit 9.

The CD-ROM control unit 12 reads necessary information from a CD-ROM storing a database 30 (FIGS. 3 and 4) constructed to efficiently extract information for navigation. In the embodiment, the number of CD-ROMs to be read and controlled is two (including the map / road information and the destination / route information, etc.). One) CD-ROM
May be read out, or reading out of three or more CD-ROMs may be controlled. Further, in the embodiment, the database constructed so as to efficiently retrieve the information for navigation is a CD-RO.
M, but is not limited to this, and may be a large-capacity and compact recording medium that can be easily attached to and detached from the navigation device main body by the user (in this case, CD-R
The OM control unit 12 is replaced by a read control unit for the recording medium).

The FM multiplex reception and processing unit 13 includes the antenna 1
3a, receives the FM multiplex wave by the antenna 13a, detects own vehicle position information on a highway or the like, and sends it to the control unit 4. The detected value is used by the control unit 4 to correct the absolute position and direction obtained from the GPS and determine the own vehicle position.

[Guidance Guide Display Means] FIG. 2 is a block diagram showing an example of the configuration of the guide map display means based on the landmark display method of the present invention.
Is configured by a program in the embodiment and stored in the memory 5.

In FIG. 2, the guide map display means 23 includes a destination, a current position, a route, etc. which are set or determined by the preceding processing (processing by the setting means 20, the route determination means 21 and the current position acquisition means 22). A road map display means 231 for displaying a road map (for one screen) including a route, an own vehicle position, a destination, a peripheral map, and the like on a predetermined scale on the display unit 10 of the navigation device 100 based on A distance determination unit 232 that obtains a distance from the next guidance point (guide point) and determines whether the difference is equal to or less than a predetermined value;
When the distance between the vehicle position and the next guide point is equal to or less than a predetermined value, map data of a certain section including the guide point is acquired from the database 30, enlarged to a predetermined size, and taken into the memory 6 (DRAM). Map import means 233
And overlap determining means 234 for determining whether or not the taxiway on the enlarged map and the landmark overlap (= whether or not the landmark protrudes into the taxiway), and when the landmark protrudes into the taxiway, Landmark display moving means for moving the display position so that the landmark does not protrude into the taxiway, and an enlarged map display for expanding and displaying the enlarged map data stored in the memory 6 in the display memory 8 (VRAM). Means 236 are provided.

In this embodiment, when the distance between the own vehicle position and the next guide point becomes smaller than a predetermined value by the distance determining means 232, the processing by the enlarged map capturing means 233 to the enlarged map display means 236 is automatically performed. In this case, the enlarged map display is performed by executing the enlarged map display means 236 to the enlarged map display means 236 only when the user selects the enlarged map display option in the setting means 20. The operation of the enlarged map capturing means 233 to the landmark display moving means 235 may be performed, but the enlarged map display means 236 is performed only when the user instructs the enlarged map selection display by operating a stick bar or the like.
May be operated to display an enlarged map. Also, as described later, the guide point information file 3
A determination code for determining whether or not to automatically enlarge and display a certain surrounding area is stored in 12 and the determination code is detected.
In addition, when the distance between the guidance point and the car is equal to or smaller than a predetermined value, the display may be automatically enlarged.

Further, in this embodiment, after the distance is judged by the distance judging means 232, the enlarged map taking in means 233 is executed.
The following operation is performed. However, the distance determination by the distance determination unit 232 is performed after the capture of the enlarged map by the enlarged map capture unit 233 to the movement of the landmark overlapping the taxiway by the landmark display movement unit 235 is performed first. It may be performed.

In this embodiment, the enlarged map capturing means 234 captures and enlarges map data of a fixed section including a guide point.
In 4, only map data of a fixed section including a guide point may be taken in, and the map data may be enlarged when expanded by the enlarged map display means 236 to the memory 8 (VRAM).

In this embodiment, the guide map display means 2 is provided.
3 to route map display means 231 to enlarged map display means 236
Although the above six modules are configured to be included, they may be further subdivided, or some or all of them may be configured by hardware.

[Navigation Database] FIG. 3
FIG. 3 is an explanatory diagram of an example of a configuration of a navigation database. In the present embodiment, the navigation database 30 is constructed so that road map information is easily extracted and stored so that the road map database 31 and the route information are easily extracted. And a route database 32 stored in a CD-ROM (both may have a known structure). The map information database stores the map information for the entire target country in a single CD-ROM. Otherwise, it is stored on a plurality of CD-ROMs, and the route database may be stored on a CD-ROM for each purpose such as sightseeing, sports, and leisure.)

The road map database 31 includes an enlarged map index file 311 (FIG. 4) configured to efficiently index the database when displaying an enlarged map, and map data (graphics or image information of roads, buildings, terrain, etc.). And icons such as characters, symbols and landmarks that mean them)
And the like, and link information (having directionality) relating guide points (nodes (intersections, corners, start and end points)) and guide points (nodes) on the road are stored. A guide point information file 313, a landmark file 314 storing the center coordinates of landmarks, the type of shape, and the like, and a name file 315 including character data expressing place names and the like are provided. Note that the guidance point information file 312 may store a determination code for determining whether or not to automatically enlarge and display a certain surrounding area.

The map data is a map of a reduced scale issued by a public organization in Japan (or other foreign countries).
This is equivalent to a map with a scale of 1 / 5,000), and map data for the number of maps covering the entire country is registered in a map file together with a map number (registered on one recording medium). If not, it is divided and registered on multiple recording media). The roads are classified into expressways, toll roads, national roads, prefectural roads, major general roads, general roads, and the like, and each is given a weighting factor used when calculating the cost of the route.

[Search File for Enlarged Map] FIG. 4 is an explanatory diagram of a configuration example of the search file for enlarged map 31 used when displaying an enlarged map. In FIG. 4, (a) is a map reference index file that associates the current position of the car with the displayed route map and the guide points (nodes) on the route map, and the index file 311 stores the coordinate range of the map data. Position coordinate column 3111, a map address column 3112 storing an index key (such as a map number) of a map and a route to be displayed when there is a car in the position coordinate range, and adjacent data storing a map number adjacent to the map It has a column 3113 and a guide point column 3114 in which a guide point number in the map is stored.

A guide point information index file (b) stores a guide point column 31141 storing guide point numbers stored in (a) one by one, and a map number including a guide point position. Map number field 3
1142, and a landmark address column 31143 storing information about each landmark displayed near the guide point (for example, a storage address (pointer) of each landmark).

[DRAM Layout Example] FIG. 5 is an explanatory diagram showing a layout example of the DRAM (memory 6) at the time of the enlarged map display operation. When the enlarged map is displayed, the DRAM 6 has a predetermined scale of normal map data + path data. Map data storage area 61 and enlarged map data storage area 62
Is secured.

FIG. 6 is a flow chart showing the operation of the control unit when the guide map is displayed. Step S3 and subsequent steps correspond to the operation of the guide map display means 23 (FIG. 2). Equivalent to. Hereinafter, the map data file 31
2 will be described with reference to FIGS. 7 and 8 assuming that the enlarged map data is included.

Step S0: (Pre-processing: setting of destination, etc.) When the setting input by the user is completed, the control unit 4 sets the departure place and the destination based on the set values.

Step S1: (Determining the Optimal Route) The control section 4 retrieves the starting point and the destination point obtained in step S0 from the memory 6 based on the route determining means 21 and departs while referring to the route database 32. Determine the optimal route from the ground to the destination.

Step S2: (Determination of the current position) The control unit 4 controls the current position acquisition unit 22 (FIG. 2) to search for the absolute position and azimuth, the relative azimuth detection unit 2, the vehicle speed detection unit 3,
An accurate current position of the own vehicle is determined based on the position information and the direction information obtained by the FM multiplex reception and processing unit 13, and the result is stored in a memory 6.
(Here, for the sake of explanation, the position of the own vehicle is shown in FIG.
(It is assumed that it is at the position of the own vehicle position guide 72 in (b)).

Step S3: (Display of Road Map) The control section 4 extracts map data of a predetermined scale including the position of the own vehicle from the road data file 312 based on the road map display means 231, and is determined in step S3. A road map is displayed with the route distinguishable from other roads (FIG. 8).
(B)). The scale of the map can be selected by the user.

Step S4: (Acquisition of the next guide point) The control unit 4 extracts the guide point on the route from the guide point of the map including the own vehicle position 72 from the enlarged map index file 311 based on the distance determination means 232. , The number (pointer) of the nearest guide point (= next guide point) B is held in the spare area of the DRAM 6.

Step S5: (Calculation and determination of distance between own vehicle position and next guide point) Next, the distance between the own vehicle position 72 and the next guide point B is calculated and a predetermined value (for example, 200) Meters) to determine whether the value is equal to or less than a predetermined value.
And the value exceeds a predetermined value (FIGS. 7B and 7C).
Returns to S2. Note that the distance between the own vehicle position (72) and the next guidance point B is determined by the coordinate value of the own vehicle position and the above-described step S.
4 can be obtained based on the coordinate value of the next guide point B obtained in step 4 (by calculating the difference between the distance from the starting point to the next guide point B and the travel distance on the route from the starting point, The distance between the vehicle position (72) and the next guide point B can also be obtained).

Step S6: (Capture of Enlarged Map) The control unit 4 uses the magnified map capture means 233 based on the pointer of the next guide point (B) held in step S3 to retrieve the enlarged map search file 30 ( Based on the map number in the map number column 31142 of FIG. 4), the map data of the section (predetermined rectangular area) near the guide point (B) is acquired from the map data file 312 including the guide point, and is reduced to a predetermined size. The enlarged map data is stored in the enlarged map data storage area 62 of the DRAM 6 and the guidance route (71)
The inclination α1, α2,... And the constant β1,
.. are acquired and stored in the spare area of the DRAM 6.

The landmark address column 31143
The landmark (75-1, 75) displayed near the guide point B from the landmark file 314 with reference to FIG.
(2, 75-3), landmark data such as information (for example, a storage address (pointer) of each landmark) relating to the center data, shape data, thickness data (width, radius, and the like) are taken out and stored in the memory.

Step S7: (Determination of Overlap between Landmark and Guideway) The control unit 4 determines that the landmark and the guideway (71) overlap on the map stored in the enlarged map data storage area 62 by the overlap determination means 234. It is checked whether or not they overlap, and if an overlap (protruding) is detected, the process proceeds to S11; otherwise, the process proceeds to S9 ((in the example of FIG. 8A, the landmarks 75-1, 75-2, Since the landmarks 75-1 and 75-2 of 75-3 overlap, S8
Transition to).

The overlap between the landmark and the guideway can be detected by judging whether or not the plane occupied by the landmark is covered by the guideway. It is sufficient to determine whether or not a line segment connecting the coordinates of four points based on the width in the x direction and the width in the y direction intersects with the side line of the taxiway represented by y = αx ± β. Therefore,
By solving a simple linear equation, it is possible to detect whether or not the landmark and the taxiway overlap (if they overlap, two intersections are obtained). If the landmark is a circle, it is sufficient to determine whether or not the equation of the circle obtained from the center coordinates and the radius intersects with the side line of the taxiway 71 represented by y = αx ± β. The presence or absence of overlap can be detected by solving the following equation. In a case where the landmark is an ellipse or a triangle, the presence or absence of the overlap can be detected in the same manner. Therefore, the above step S6
, A landmark expression calculated based on the center coordinates, shape data, and thickness data of the landmark held in the spare area of the DRAM 6, the slope α and the constant of the guide path held in the spare area of the DRAM 6 in step S6. The presence or absence of landmark overlap can be detected from the linear expression expressed by the data.

It should be noted that in addition to the above-described method of judging the presence or absence of the overlap, it is also possible to detect the change in the color or luminance occurring in the landmark when the landmark overlaps the taxiway to detect the presence or absence of the overlap. .

Step S8: (Determination of the direction of movement of the landmark with respect to the taxiway) The control unit 4 shifts the landmark without changing the positional relationship with the taxiway (for example, the land on the right side of the taxiway). If there is a mark, the landmark display moving means 235 first determines the arrangement state of the overlapping landmarks with respect to the taxiway, based on the positional relationship between the landmarks. The moving direction and the moving amount are determined. In other words, the landmark is shifted without changing the positional relationship with the taxiway (for example, when there is a landmark on the right side of the taxiway, it is on the right side after the movement).

When the overlap is determined by calculation in step S7, the landmarks are arranged in the X and Y directions (+, +), (+,-), (+,-), (-,
+) Or (-,-), so two overlapping positions (coordinates) and landmark positions (center coordinates)
Can be determined based on which of the above-mentioned four patterns the difference in coordinate values belongs to. In addition, the moving direction for moving so as not to overlap is opposite to the direction of the determined pattern (for example, when the positional relationship with the taxiway is (+,-), the moving direction is (-,-). +)). Further, since the landmark may be moved in parallel with the inclination of the taxiway until the taxiway and the landmark no longer overlap with each other, assuming that the movement amount in the Y direction at that time is Δy, y = αx ± The movement amount in the x direction from β is = Δy / α. Specifically, the difference between the larger y value of the two intersections and the y value of the landmark may be obtained as Δy, and the movement amount (Δy,
Δx = Δy / α).

When the landmark overlaps the taxiway and the change in color or luminance occurring in the landmark is detected to detect the presence or absence of the overlap, the size of the overlapped portion and the portion not overlapped is detected. The relative position and the moving direction of the landmark are determined from the comparison of the distances, and the moving amount can be obtained from the ratio.

Step S9: (Movement of Landmark) Based on the movement amount and movement direction obtained in step S8, the landmark is first moved in the X movement direction by the movement amount in the X direction, and then the movement of Y is performed. The landmark is moved in the direction by the moving amount in the Y direction (in the example of FIG. 8, the overlap of the landmark 75-1 overlapping the left side of the taxiway as shown in FIG. About Taxiway 7
The overlap has been resolved in relation to 1).

Step S10: (intersection (next taxiway)
There is an intersection at an intersection (there is at least one taxiway from the next guidance point to the next guidance point), so even if the overlap between the landmark and the taxiway is resolved, the next taxiway (Ie, FIG. 8
As shown in the example of (b), the overlap is eliminated in relation to the taxiway 71, but the landmark 75-2 is still overlapped in relation to the taxiway (crossroad) 71 'at the guide point B.) .

Therefore, the control section 4 checks the guide point information file 313 to determine whether or not there is a guideway connected to the guide point.
When there is such a taxiway, the position of the landmark is fixed at the position after the movement in step S8, and the previous taxiway is replaced with a new taxiway (the example in FIG. 8). Then, the guideway 71 is replaced with the guideway 71 ') and the process returns to S7 (this causes the guideway 71 to be replaced as shown in FIG. 8C).
The overlap between 1 ′ and the landmark 75-2 is eliminated).
By repeating the above steps S7 to S9, all landmarks protruding into the taxiway near the intersection can be moved.

Step S11: (Enlarged Map Display) The control unit 4 controls the DRAM 6 by using the enlarged map display means 236.
The expanded map data stored in the expanded map data storage area 62 is expanded and displayed on the display memory 8 (VRAM). As a result, an enlarged map having no landmarks protruding (overlapping) on the taxiway is displayed.
In the case of, the visibility of the intersection becomes better. Also, even when the vehicle position (guide (72)) approaches the intersection, it can be clearly recognized.

In the embodiment, as shown in FIG. 7D, the display screen is divided into two, and a road map (normal road map including the position of the own vehicle) 11 "is displayed on the right side, and the left side is displayed on the left side. Although the enlarged map is displayed on the screen, the present invention is not limited to these display methods.

In the above flowchart, step S
When the distance between the own vehicle position and the next guidance point becomes equal to or less than a predetermined value in step 5, the process automatically shifts to step S6 and S6 to S6.
In step S11, the enlarged map is displayed in step S11. However, after step S3, a step of determining whether or not the user has selected the step S0 enlarged map display option is provided. Only when the display option is selected, the operations of steps S6 to S11 may be performed to display an enlarged map.

The operations of steps S6 to S10 are performed, but the enlarged map display means 236 is operated to display the enlarged map only when the user instructs the enlarged map selection display by operating the stick bar or the like. Is also good.

If the guide point information file 312 stores a discrimination code for determining whether or not to automatically enlarge and display the surrounding fixed section, a step for detecting this discrimination code is provided after step S3. When there is an enlarged display discrimination code and the distance between the guidance point and the car is equal to or less than a predetermined value (S5), the operation of step S6 and subsequent steps may be performed to display an enlarged map. Step S5 after performing the distance determination of S5
Although the operations from 6 to S10 are performed, the distance determination in step S5 may be performed after step S10, and the enlarged display in step S11 may be performed when the distance is equal to or less than the predetermined distance.

In the example of the flowchart described above, the map data of the fixed section including the guide point is fetched and enlarged in step S6, but only the map data of the fixed section including the guide point is fetched in step S6.
VRAM by enlarged map display means in step S11
8 may be expanded at the time of development.

[Example of Enlarged Map Display] FIG. 7 is an explanatory diagram of an enlarged map display. FIG. 7A shows an example in which the route map 11 and the enlarged map 12 displayed on the screen are displayed. The enlarged map 12 is a map in which a section including an intersection (guide point A) on the route map 11 is enlarged. In this example, the enlarged map is arranged on the left half of the screen, and the road map (normal map) is arranged on the right side of the screen. I have. As described above, the enlarged map is displayed when the distance between the next guidance point (in this case, guidance point A) and the car (represented by the arrow guide 72) is equal to or less than a predetermined value. In this example, the enlarged map is arranged on the left half of the screen, and the route map (normal map) is arranged on the right side of the screen. However, the present invention is not limited to this display method.

(B) shows the route map 1 by deleting the enlarged map display because the car (72) has passed the guide point A.
This is an example in which 1 'is displayed on the entire screen.

In (c), the route map 11 ′ including the next guide point B is displayed after the car (72) travels a little after passing the guide point A. This is an example in which the route map 11 'is displayed on the entire screen because the distance to is still larger than the predetermined value.

In the case (d), as the car (72) further travels and approaches the guide point B, the distance from the guide point B becomes smaller than a predetermined value. Enlarged map 1 with the section including the intersection) enlarged
This is an example in which 2 "is arranged on the left side of the screen, and the route map 11" is reduced to half and arranged on the right side of the screen for display.

[Landmark Display Movement Example] FIG. 8 is an explanatory diagram of a landmark display movement method according to the present invention. In FIG. 8, (a) is an example of an intersection (guide point) having a landmark protruding and displayed on the taxiway, and the landmarks 75-1 and 75-2 overlap. Also,
(B) is a diagram showing a process of performing the landmark display movement according to the present invention, in which the landmark 75-1 and the landmark 75-2 are moved in a direction away from the guideway 71 to eliminate the protrusion. (Although the protrusions of the taxiway 71 have been eliminated along with the landmarks 75-1 and 75-2, the landmark 75-2 is not included in the taxiway 71 '.
Still protrudes in the Y-axis direction). (C) Taxiway 7
Landmark 7 to eliminate overhang to 1 '
This shows the result of moving the landmark 75-2 from the guideway 71 'of 5-2, and the protrusion of the landmark 75-2 is completely eliminated.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made.

[0071]

As described above, according to the present invention, at the time of guidance by the navigation device, the guide map is displayed after shifting the landmarks protruding into the taxiway so as not to overlap the taxiway. Better visibility on curves.

Also, when a guide map including the guide point is displayed when the distance between the next guide point and the host vehicle is equal to or less than a predetermined value, there is no landmark protruding from the guide path and displayed. Even if the position (guide) approaches an intersection with many landmarks, it can be clearly recognized, so that safe and reliable guidance can be performed.

Further, it is not necessary to recreate the database so as to display landmarks protruding into the taxiway, and a conventional database including landmarks can be used, so that there is no burden on the user and the database maker.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a navigation device to which a landmark display method according to the present invention can be applied.

FIG. 2 is a block diagram showing a configuration example of a guide map display means based on the landmark display method of the present invention.

FIG. 3 is an explanatory diagram of a configuration example of a navigation database.

FIG. 4 is an explanatory diagram of a configuration example of an enlarged map search file used when displaying an enlarged map.

FIG. 5 is an explanatory diagram showing a layout example of a DRAM during an enlarged map display operation.

FIG. 6 is a flowchart showing an operation when a guidance map is displayed.

FIG. 7 is an explanatory diagram of an enlarged map display.

FIG. 8 is an explanatory diagram of a landmark display moving method according to the present invention.

FIG. 9 is a diagram showing an example of a guidance display according to the related art.

[Explanation of symbols]

22 Current position acquisition means 71, 91 Taxiway 72, 92 Own vehicle position guide (current position of car) 75-1 to 75-3, 95-1 to 95-3 Landmark 100 Navigation device 232 Distance determination means (Distance acquisition means 233 distance acquisition means 234 overlap determination means (overlap detection means) 235 landmark display movement means (map display means) 236 enlarged map display means (map display means) A, B guidance points

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C032 HB06 HC24 HC26 HD04 HD16 2F029 AA02 AB01 AB07 AB13 AC02 AC09 AC14 AC19 5H180 AA01 BB13 EE18 FF04 FF05 FF22 FF27 FF35

Claims (8)

[Claims] 1. An on-vehicle navigation device for detecting the presence or absence of a landmark protruding and displayed on a taxiway in a section including a next guide point, and detecting a landmark protruding on the taxiway when the landmark is detected. A landmark display method, wherein a mark is moved and displayed so as not to protrude into a taxiway. 2. The landmark display method according to claim 1, wherein the section including the guide point is enlarged and displayed when a distance between the car and the guide point becomes a predetermined value or less. 3. The landmark display method according to claim 1, wherein the guide point is an intersection. 4. A navigation device for displaying a route from a current position of a car to a destination on a map and displaying the route, and for assisting driving, a map capturing means for loading a map of a section including a next guide point into a memory; Overlap detecting means for detecting the presence or absence of an overlap between a landmark and a taxiway on the map of the captured section; and displaying a landmark in which the overlap is detected when there is a landmark in which the overlap is detected by the overlap detecting means. A navigation device, comprising: map display means for displaying a map of the section after moving within the section so that the position does not overlap the taxiway. 5. A current position obtaining means for obtaining a current position of a car, a distance obtaining means for obtaining a distance between a current position of the car obtained by the current position obtaining means and a next guide point, and the distance obtaining means. Distance determining means for comparing the distance obtained by the means with a predetermined value to determine the magnitude of the distance, wherein the map display means uses the distance determining means to determine the current position of the car and the next guidance point. When the distance is determined to be equal to or less than the predetermined value, each of the landmarks overlapping the taxiway is moved within the section so as not to overlap the taxiway while maintaining the positional relationship with the taxiway, and then the section The navigation device according to claim 4, wherein a map is displayed. 6. The navigation device according to claim 4, wherein the map fetching means fetches a map of a section including a next guide point into a memory after expanding the map to a predetermined size. 7. The map taking means, when the distance determining means determines that the distance between the current position of the car and the next guide point is equal to or less than the predetermined value, creates a map of a section including the next guide point. 6. The navigation device according to claim 5, wherein the navigation device is enlarged to a predetermined size and stored in a memory. 8. The map display means includes an enlarged map display means for enlarging and displaying a map of the section to a predetermined size, and after the display position of the landmark is moved, a map of the section is displayed by the enlarged map display means. 6. The navigation device according to claim 4, wherein the navigation device is displayed in an enlarged manner.