JPH05142995A - Course guiding method for on-vehicle navigator - Google Patents

Abstract

PURPOSE:To easily recognize which of guide courses is directed to a destination. CONSTITUTION:A guide course search part 15 previously searches for the best guide course connecting a starting point and the destination by referring to map data on a CD-ROM and stores it in a guide course memory 16. During a travel, a vehicle position detection part 3 detects the current position of a vehicle and a destination direction calculation part calculates the destination direction viewed from the current position of the vehicle; and a map image drawing part 13 and a rotation part 20 while using the map data and guide course data a map of the periphery of the current place of the vehicle and a map image including the guide course and a vehicle position mark emphasized and superimposed on the map on the screen of a CRT display device 4 so that the destination direction moves facing in a constant specific direction to the screen irrelevantly to the movement of the vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route guidance method for a vehicle-mounted navigator, and more particularly to a route guidance method for a vehicle-mounted navigator in which a guidance route is emphasized on a map and displayed on a screen.

[0002]

2. Description of the Related Art There is a vehicle-mounted navigator that guides a vehicle so that a driver can easily reach a desired destination. In this in-vehicle navigator, the position of the vehicle is detected, the map data around the vehicle position is read from the CD-ROM, the map image is drawn in the V-RAM, and the vehicle position mark is superimposed on a predetermined position on the map image. Draw and
The V-RAM image is output to the CRT display device while being converted into a video signal and displayed on the screen. Then, as the current position changes due to the movement of the vehicle, the vehicle position mark on the screen is moved, or the vehicle position mark is fixed at the center of the screen and the map is scrolled to constantly display the map around the vehicle position. Information is available at a glance.

The map stored in the CD-ROM is divided into areas of a longitude width and latitude width of appropriate sizes according to the scale level, and roads are represented by vertices (nodes) represented by coordinates of longitude and latitude. ) Is shown as a set. A part that connects two or more nodes is called a link. The road data included in each map is, as shown in FIG. 10, a road list RLDT, a node table NDTB, and an intersection node list CRDT.
The road list RLDT is
Regarding the road, data indicating the type of road such as national road, highway, and other roads, the number of all nodes on the road, the number on the node table NDTB of each node that constitutes the road, and the width of the road between the nodes It is composed of. The width data of the nth node number indicates the width of the road (link) connecting the node related to the nth node number and the node related to the (n + 1) th node number. Further, the intersection constituent node list CRDT is a set of numbers on the node table NDTB of the nodes (referred to as intersection constituent nodes) closest to the intersection on the link connecting to the intersection for each intersection on the map. Is a list of all nodes on the map, coordinate information (longitude, latitude) for each node, an intersection identification flag indicating whether or not the node is an intersection, intersection data if it is an intersection, It is composed of a pointer or the like that points to the road link to which the node belongs.

In such an in-vehicle navigator, map data is used to search for an optimum guide route connecting a starting point to a destination, and the guide route data is stored in a guide route memory so as to guide the driver while traveling. Using the guide route data stored in the route memory, the guide route highlighted in bold in a specific color is overlaid on the map image on the screen, and the route guide is designed to guide the predetermined route from the departure point to the destination. Some have functions. According to such a route guidance function, a desired destination can be easily and surely reached at the time of leisure or business simply by traveling according to the route guidance displayed on the screen.

[0005]

Conventionally, in the method of displaying a map image including a guide route on the screen, as shown by the solid line A in FIG. 11, while traveling, the north direction on the map image is always on the screen. There is a north-up mode method in which the vehicle is directed to the vehicle, and a heading-up mode method in which the vehicle traveling direction on the map image is always directed to the upper side of the screen while traveling as shown by the dashed line B in FIG. Then, the display is performed in only one mode, or in one of the two modes selected by the user's operation.

However, when the vehicle is located away from both the starting point and the destination and there is no starting point or destination in the map image displayed on the screen, which direction of the guide route is the destination? It ’s hard to tell if it ’s going to
In particular, if you depart from the guide route due to a meal or the like (see FIG. 11), when you return to the guide route again, you may be confused as to which direction you should drive, and sometimes you may run backward to the place of departure. There was a problem of wasting time and wasting time.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a route guidance method for an in-vehicle navigator capable of easily grasping which direction of a guidance route is toward a destination.

[0008]

According to one aspect of the present invention, the above problem is solved by referring to the map information storage means storing map data and the map data stored in the map information storage means from the starting point to the destination. A means for searching for the optimum guide route connecting the routes, a guide route memory for storing the guide route data, a means for detecting the current location of the running vehicle, and a departure direction or a destination direction viewed from the current location of the vehicle. Using the means for calculating, the map data and the guide route data, a map image including the map around the current position of the vehicle and the guide route and the vehicle position mark which are emphasized on the map is started regardless of the movement of the vehicle. This is achieved by providing means for displaying on the screen while moving so that the direction of the ground or the direction of the destination is directed to a predetermined fixed direction with respect to the screen.

According to another aspect of the present invention, a map information storage unit storing map data and an optimum connection from a starting point to a destination are referred to by referring to the map data stored in the map information storing unit. A means for searching for a guide route, a guide route memory for storing guide route data, a means for selecting a desired one from a plurality of display modes, a means for detecting the current position of a running vehicle, A means for calculating the direction of the starting point or the direction of the destination viewed from the current position, and a map around the current position of the vehicle, and a guide route and a vehicle position mark that are emphasized on the map, using the map data and the guide route data. Means are provided for displaying the map image on the screen in the selected one display mode, and the means is provided for the direction of departure regardless of the movement of the vehicle while traveling under the selection of the departure place orientation mode or the destination orientation mode. Others are achieved by that is configured to display on the screen while moving the map image so as to face a predetermined certain direction the destination direction relative screen.

[0010]

According to one aspect of the present invention, while traveling, the present location of the vehicle is detected, and the direction of the starting point or the destination of the vehicle as viewed from the present location of the vehicle is calculated, and the map data and the guide route data are used. , A map image including a map around the vehicle's current location and a guide route and a vehicle position mark that are emphasized on the map, regardless of the movement of the vehicle, the direction of departure or the direction of the destination is a predetermined fixed direction with respect to the screen. Display on the screen while moving to face. As a result, even if there is neither a departure point nor a destination on the map image on the screen, by comparing the predetermined fixed direction of the screen with the direction of the guide route displayed on the screen, the guide route can be easily displayed. It is possible to know which direction is the direction toward the destination, and when the vehicle deviates from the guide route for a while during traveling and is going to return to the guide route again, it is possible to travel in the correct direction without getting lost.

According to another aspect of the present invention, while the vehicle is traveling in the departure point-oriented mode or the destination-oriented mode, the current location of the vehicle is detected, and the direction of the departure location or the destination direction viewed from the current location of the vehicle is detected. Is calculated, and a map image including the map around the current position of the vehicle and the guidance route and the vehicle position mark that are emphasized on the map is calculated using the map data and the guidance route data, regardless of the movement of the vehicle. It is displayed on the screen while moving so that the direction or the destination direction is directed to a predetermined fixed direction with respect to the screen. As a result, only when confirmation of the destination direction is required, the map image on the screen is displayed so that the departure direction or the destination direction faces a predetermined certain direction with respect to the screen, and the confirmation of the destination direction is not particularly necessary. At this time, it can be displayed in another desired mode.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of an in-vehicle navigator embodying a route guidance method according to the present invention.

In the figure, 1 is a CD-ROM that serves as map data storage means, 2 is an operation panel, and scroll keys for left, right, up, and down directions, route guidance mode setting keys, display mode selection keys, and destinations. Equipped with input keys, map search, enlargement / reduction keys, start key, etc. Reference numeral 3 is a vehicle position detection unit for detecting the vehicle direction and vehicle position by self-contained navigation, and 4 is a CRT display device, which inputs a video signal and displays a map on a screen together with a cursor mark, a vehicle position mark, an emphasis guide route, etc. To do. The display mode is a north-up mode in which the north on the map image always faces upward on the screen, and a map image so that the vehicle traveling direction always faces upward on the screen regardless of the movement of the vehicle. Heading-up mode that displays while moving, and destination-up mode that displays while moving the map image so that the destination direction viewed from the vehicle position is always the top of the screen regardless of the movement of the vehicle (destination-oriented mode). mode)
You can switch between the three.

Reference numeral 10 denotes a navigation controller having a microcomputer configuration, which determines an optimum guide route from a starting point and a destination by simulation calculation, and a map image around the vehicle position, if necessary, a cursor mark, a vehicle position mark, and an emphasis guide. It is displayed on the screen of the CRT display device 4 together with the route. Of these, 11 is CD-
A buffer memory for temporarily storing the map data read out from the ROM 1, and 12 is a cursor position calculation unit, and a scroll key of the operation panel 2, a map search, a key for enlarging / reducing, etc. can be used for map selection operation and scroll operation. When this is done, the longitude and latitude corresponding to the center of the map on the screen are calculated and output as the cursor position. Reference numeral 13 denotes a map image drawing unit which, before starting traveling, stores the data of a desired map selected by the map search and enlargement / reduction keys of the operation panel 2 and surrounding map data from the CD-ROM 1 to the buffer memory 11. As well as reading out, nine map images including the desired map and the peripheral map are drawn in the first V-RAM described later, or as the cursor position data input from the cursor position calculation unit 12 changes according to the scroll operation. , If necessary, while reading new map data from the CD-ROM 1 to the buffer memory 11, the map image of the first V-RAM is rewritten so that the cursor position is always in the center, and
A cursor mark is drawn in the center of the first V-RAM. In addition, the map image drawing unit 13 may add new map data to the CD-ROM 1 as necessary as the vehicle position data output from the vehicle position detecting unit 3 changes while the vehicle is running (after the start key of the operation panel 2 is pressed). The map image of the first V-RAM is rewritten so that the current position is in the center and the north is upward while being read from the buffer memory 11 to the buffer memory 11. In addition, the map image drawing unit 13 displays the vehicle position mark based on the vehicle direction data input from the vehicle position detection unit 3 while the vehicle is traveling.
In the route guidance mode, the route is drawn in the center of the AM in a predetermined direction, and within the range of the map image currently drawn in the first V-RAM from the route data stored in the later-described guidance route memory. Input the guide route data to be entered, and draw the guide route that is emphasized in a color different from that of other roads (see FIG. 2).

Reference numeral 14 denotes a destination setting unit, which is set to a route guidance mode by the operation panel 2 before the start of traveling, and after the cursor on the center of the screen is aligned with the destination by the operation of the operation panel 2, the destination is input. When the key is pressed, the output of the cursor position calculation unit 12 at that time is set as the destination data.

Reference numeral 15 denotes a guide route search unit which, when in the route guide mode, inputs a destination by operating a scroll key or a destination input key before starting traveling (before pressing the start key). The current position data (departure point data) is input from the vehicle position detection unit 3, the destination data is input from the destination setting unit 14, and various map data from the current position to the destination are input from the CD-ROM 1 to the buffer memory 11. Simultaneously reading out the map data that has been read out, the simulation calculation for various routes is performed, and for example, the shortest distance is used as an index to find the optimum guide route from the current position to the destination, and the sequence of routes forming the guide route is calculated. Of the node sequence (each node includes the coordinates of longitude and latitude) as guide route data in the guide route memory described later. Each node in the node column is extracted from the node table of map data (see NDTB in FIG. 10).

A guide route memory 16 stores the guide route data, and stores the guide route data obtained by the guide route searching unit 15. When the starting point and the destination do not match the nodes in the road data, they are approximated by a nearby node and stored. Reference numeral 17 denotes a first V-RAM, which is a map image drawn by the map image drawing unit 13 (including a cursor mark during a scroll operation before the start of traveling, and a vehicle position mark and other objects during traveling in the route guidance mode). The road including a thick highlighted guide route that is different in color from the road is stored with the north facing upward (an example of running in the route guide mode is shown in FIG. 2). 18 is a second V-RAM, a first V-
Of the map image drawn in the RAM, a predetermined one screen range is drawn. A destination direction calculation unit 19 calculates the destination direction viewed from the current position of the vehicle based on the vehicle position data detected by the vehicle position detection unit 3 and the destination data stored in the guide route memory 16.

Reference numeral 20 denotes a rotating unit which, when the display mode is the destination up mode, displays the map image drawn in the first V-RAM 17 on the basis of the destination direction data input from the destination direction calculation unit 19. Rotate by the angle of the difference between the north direction and the direction of the destination so that the direction of the destination is upward as the center, and cut out the range for one screen (see the alternate long and short dash line A in FIG. 2) and write it in the second V-RAM 18. , When the display mode is the heading-up mode, based on the vehicle direction data input from the vehicle position detection unit 3,
The map image drawn in the first V-RAM 17 is rotated by the angle of the difference between the north azimuth and the vehicle azimuth so that the vehicle advancing direction is upward with the center as the center, and the range for one screen is cut out to the second V -Write to RAM 18.
However, when the display mode is the north-up mode, the rotating unit 20 does not rotate the range of one screen centered on the center of the map image drawn in the first V-RAM 17 and the second V-RAM 18 keeps the north facing upward. Write in.

Reference numeral 21 is a video converter for converting the image data read from the second V-RAM 18 into a video signal and outputting the video signal to the CRT display device 4.

3 and 4 are flow charts showing the route guidance processing of the navigation controller 10, FIG. 5 is an explanatory diagram showing an example of the guidance route, and FIGS. 6 to 8 are explanatory diagrams of screen display examples of the CRT display device 4. Yes, and will be described below with reference to these figures.

First, when a map search operation on the operation panel 2 and a selection operation of a map of a desired area at a desired scale are performed by operating keys for enlarging / reducing, the map image drawing unit 13 causes the desired map from the CD-ROM 1. And the map data of the surrounding area is a buffer memory 1
In addition to reading out to 1, the map image is drawn on the first V-RAM 17 so that the north faces upward. First V-RAM1
The map image drawn in FIG. 7 is rotated by the rotating unit 20 so that the range of one screen centered on the center is the second direction with the north facing upward.
It is written in the V-RAM 18. The image data stored in the second V-RAM 18 is output to the video conversion unit 21, converted into a video signal by the video conversion unit 21, and output to the CRT display device 4. The CRT display device 4 displays a map on the screen based on the input video signal (see FIG. 3).
Steps 101 and 102). Subsequently, when the route guidance mode setting operation is performed by pressing the route guidance mode setting key on the operation panel 2 (steps 103 and 104), the map image drawing unit 13 draws a cursor mark in the center of the first V-RAM 17. , A cursor mark is displayed in the center of the map image on the screen (step 105). At this time, the cursor position calculator 12 calculates the cursor position at the center of the screen (step 106).

When the scroll key of the operation panel 2 is operated, the cursor position calculation unit 12 calculates the cursor position (coordinates of longitude and latitude) (steps 107, 10).
8) The map image drawing unit 13 reads out predetermined map data from the CD-ROM 1 to the buffer memory 11 according to the change of the cursor position, and in the first V-RAM 17, the center is always the cursor position and the north is upward. In this way, the map image is drawn and the first V-RAM 17
Draw a cursor mark in the center of. First V-RAM1
The map image drawn in FIG. 7 is rotated by the rotating unit 20 so that the range of one screen centered on the center is the second direction with the north facing upward.
It is written in the V-RAM 18. As a result, the map on the screen moves in accordance with the scroll operation with the cursor mark displayed in the center of the screen (steps 109 and 11).
0).

The driver uses the present location as the starting location S and the destination O
When the user wants to go up (see FIG. 5), when the cursor mark on the screen reaches the destination O, the cursor is turned on and the destination input key of the operation panel 2 is pressed (step 111). Then, the destination setting unit 14 sets / registers the cursor position data output from the cursor position calculation unit 12 at that time as the destination data (step 112).

In this way, when the input of the destination O is completed, the guide route search unit 15 inputs the current position data from the vehicle position detection unit 3 as the departure point data and the destination data from the destination setting unit 14. input. And C
While reading the map data from the starting point S to the destination O from the D-ROM 1 to the buffer memory 11, the simulation calculation is repeated to search for the optimum guide route with the shortest distance as an index, for example, and to form a series of the guide routes. The node sequence of is stored in the guide route memory 16 as guide route data (step 113, see FIG. 5). The departure point data stored at the top of the guide route memory 16 is the departure point S.
And the destination data stored at the end of the guide route memory 16 is the node data closest to the destination O.

Next, when the start key is pressed on the operation panel 2 (step 114), the display mode is automatically set to the destination up mode in the navigation controller 10 (step 115), and then the map image drawing unit 13 is set to the current location ( The map data around the departure point) is read from the CD-ROM 1 to the buffer memory 11, and a map image is drawn on the first V-RAM 17 so that the center is the departure point (step 116). Then, the map image drawing unit 13 selects one of the guide route data stored in the guide route memory 16,
A node included in the range of the map image of the first V-RAM 17 is read out, and based on these data, an emphasized guide route for route guidance is drawn on the first V-RAM 17 in a color different from that of other roads and thick (step). 117), the vehicle position mark is drawn at the center in the direction indicated by the vehicle direction data (step 2118).

When the display mode is the destination up mode,
The destination direction calculation unit 19 calculates the destination direction viewed from the current position of the vehicle (initially the departure place) from the vehicle position data and the destination data stored in the guide route memory 16, and the destination direction data is stored in the rotation unit 20. Output to (Step 2 in FIG. 4)
01, 202). Then, the rotating unit 20 uses the first V-RA.
The map image drawn in M17 is rotated by the angle of the difference between the north azimuth and the direction of the destination so that the direction of the destination is upward with the center as the center, and the range for one screen is cut out to obtain the second V-RAM18. Write to (step 20
3). The image data of the second V-RAM 18 is the image conversion unit 2
In step 1, the video signal is converted into a video signal, which is output to the CRT display device 4 and displayed on the screen (step 204). As a result, the map around the departure point with the vehicle position mark at the center departure point is displayed on the screen with the destination direction facing up, and the guidance route is highlighted in a different color from other roads and thickened. Since it is displayed, it is possible to know at a glance along which road the vehicle can travel to reach the destination (see FIG. 6 (1)).

When the vehicle starts traveling, the vehicle position detecting section 3 detects the vehicle position and the vehicle azimuth every time the vehicle travels a certain distance by the self-contained navigation from the starting point S as a starting point, and outputs the vehicle position data and the vehicle azimuth data. The map image drawing unit 13 receives the vehicle position data and the vehicle direction data (step 20).
5) While reading predetermined map data including vehicle position data from the CD-ROM 1 into the buffer memory 11,
A map image is drawn on the V-RAM 17 so that the center is the vehicle position and the north is the upward direction (step 11 in FIG. 3).
6). Then, of the guide route data stored in the guide route memory 16, the nodes within the range of the map image of the first V-RAM 17 are read out, and based on these data, the first V-thick in a different color from other roads is drawn. The enhanced guide route is drawn on the RAM 17 (step 117), and the vehicle position mark is also drawn in the center of the first V-RAM 17 in the direction indicated by the vehicle direction (step 118).

Next, the destination direction calculation unit 19 calculates the destination direction from the current position of the vehicle based on the vehicle position data and the destination data stored in the guide route memory 16, and the destination direction data is sent to the rotation unit 20. It is output (steps 201 and 202 in FIG. 4). Then, the rotating unit 20 is the first VR
The map image drawn in AM17 is rotated by the angle of the difference between the north direction and the direction of the destination so that the direction of the destination is upward with the center as the center, and the range for one screen is cut out to obtain the second V-RAM18. Write to (step 2
03). As a result, the map on the screen
It always moves so that the center is the vehicle position and the top of the screen is the direction of the destination (combining parallel movement and rotation movement), and the emphasis guidance route is integrated with the map. Move on.

As described above, in the destination up mode, the direction of the destination viewed from the current position of the vehicle is calculated while traveling,
Regardless of the movement of the vehicle, the map image is always displayed while moving so that the destination direction faces the top of the screen, so traveling progresses, and neither the departure place nor the destination exists on the screen. By the way, even if the user deviates from the guide route due to the need for food or the like, the direction on the screen is the direction toward the destination as shown in FIG. 6B, so the direction of the guide route is compared with the direction on the screen. Thus, it is possible to easily determine which direction of the guide route is the destination direction. For this reason,
When returning to the guide route while taking a route closer to the destination (see the broken line A in Fig. 6 (2)) when returning to the guide route after finishing the requirement As shown in FIG. 6 (3), since the destination direction is the upward direction of the screen, it is possible to easily discriminate which direction the vehicle can travel correctly on the guide route toward the destination. Will not get lost in any direction and will not accidentally reverse the guide route.

Even if the destination direction is not always displayed upward, it is known which direction of the guide route is the destination direction, and when the heading-up mode is easier to drive, At any time after pressing the start key in step 114 of FIG.
Use to select the display mode and select the heading-up mode. Then, the display mode is set to the heading-up mode in the navigation controller 10 (steps 206 to 208 in FIG. 4). At this time,
The rotating unit 20 uses the map image drawn in the first V-RAM 17 based on the vehicle direction data input from the vehicle position detecting unit 3 so that the vehicle traveling direction is upward with the center as the center so that the vehicle traveling direction is upward. The second V-RAM is rotated by rotating the angle of the difference of
18 (steps 201 and 209). Second V-
The image data in the RAM 18 is converted into a video signal by the video conversion unit 21, output to the CRT display device 4, and displayed on the screen (step 204). As a result, a map around the central vehicle position is displayed on the screen with the vehicle traveling direction facing upward (see FIG. 7).

As described above, in the heading-up mode, the map image is always moved and displayed on the screen so that the vehicle traveling direction is upward regardless of the movement of the vehicle. When it is necessary to change the course at the intersection, it becomes easy to know which direction to turn. However, the map image on the screen is rotated every time the vehicle changes its course, which may be difficult to see. In the destination up mode described above, the map image on the screen does not rotate significantly even if the vehicle changes its course, and it does not become difficult to see.

Further, when the driver wants to display in the north-up mode, at any time after pressing the start key in step 114 of FIG. 3, a display mode selection operation is performed on the operation unit 2 to select the north-up mode. do.
Then, the display mode is set to the north-up mode in the navigation controller 10 (steps 206 to 208 in FIG. 4). At this time, the rotating unit 20 moves the first V-
The map image drawn in the RAM 17 is cut out in a range of one screen with the center facing the center and the north facing upward.
Write to V-RAM 18 (steps 201, 21)
0). The image data of the second V-RAM 18 is the image conversion unit 2
In step 1, the video signal is converted into a video signal, which is output to the CRT display device 4 and displayed on the screen (step 204). As a result, a map around the central vehicle position is displayed on the screen with north facing up (see FIG. 8). Therefore, it becomes easy to check the names of municipalities and rivers.

While the vehicle is traveling with the display mode switched to the heading-up mode or north-up mode,
Again, when you want to confirm which direction of the guide route is the destination direction, perform the display mode selection operation on the operation unit 2,
Select the destination up mode. Then, the display mode is set to the destination up mode in the navigation controller 10 (steps 206 to 208 in FIG. 4),
As described above, the map image with the destination direction facing upward on the screen is displayed (steps 201 to 203, 20).
4) By comparing the direction of the guide route and the direction on the screen, it is possible to easily determine which direction is the destination direction.

In the above embodiment, one of the three modes of destination up mode, heading up mode and north up mode can be set by selecting the display mode. You can select the desired one from the two modes of destination up mode and heading up mode, or you can select the desired one from the two modes of destination up mode and north up mode. You may do it.

Further, in the above-mentioned embodiment, the destination up mode is taken as an example of the destination orientation mode, and the top of the screen is displayed as the destination direction. A destination-oriented mode in which another fixed direction is displayed as the destination direction may be used.

Further, the destination-oriented mode is changed to the departure-point oriented mode, and the destination direction calculation unit in the navigation controller is changed to the departure direction calculation unit so that the current position of the vehicle is detected by the departure direction calculation unit during traveling. The direction of the departure place as viewed from is calculated, and the rotating unit rotates the map image drawn in the first V-RAM 17 so that the direction of the departure place is downward with respect to the center, and the difference between the south direction and the direction of the departure place is calculated. Rotate only by an angle and cut out the range for one screen to make the second V-
The map image may be written in the RAM and displayed on the screen while moving so that the departure point direction faces the bottom of the screen regardless of the movement of the vehicle (see FIG. 9). Further, in this departure point orientation mode, another fixed direction such as right, left or top of the screen may be displayed as the departure point direction.

[0037]

As described above, according to one aspect of the present invention, while traveling, the present location of the vehicle is detected, and the direction of the starting point or the destination of the vehicle as viewed from the present location of the vehicle is calculated, and the map data and the guide route data are obtained. A map image including a map around the vehicle's current location and a guide route and a vehicle position mark that are emphasized on the map is used to determine the departure direction or the destination direction on the screen regardless of the movement of the vehicle. Since it is configured to display on the screen while moving so as to face in a certain direction, even if there is neither a departure place nor a destination on the map image of the screen By comparing the directions of the guide routes that were set, it is possible to easily know which direction of the guide route is toward the destination.During travelling, the guide route deviates from the guide route and returns to the guide route. When trying It is possible to travel in the right direction without hesitation.

According to another aspect of the present invention, while traveling in the departure point-oriented mode or the destination-oriented mode, the current location of the vehicle is detected, and the direction of the departure location or the destination direction viewed from the current location of the vehicle is detected. Is calculated, and a map image including the map around the current position of the vehicle and the guidance route and the vehicle position mark that are emphasized on the map is calculated using the map data and the guidance route data, regardless of the movement of the vehicle. Since it is configured to be displayed on the screen while moving so that the direction or destination direction is directed to a certain fixed direction with respect to the screen, the departure direction or the destination direction is displayed on the screen only when confirmation of the destination direction is necessary. On the other hand, when the map image on the screen is displayed so as to face a predetermined fixed direction, and it is not particularly necessary to confirm the destination direction, it can be displayed in another desired mode.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an in-vehicle navigator embodying a route guidance method according to the present invention.

FIG. 2 is an explanatory diagram of a map image drawn on a first V-RAM.

FIG. 3 is a first flowchart showing a route guidance process of a navigation controller.

FIG. 4 is a second flowchart showing the route guidance processing of the navigation controller.

FIG. 5 is an explanatory diagram showing an example of a guide route.

FIG. 6 is an explanatory diagram showing a screen display example of a CRT display device in a destination up mode.

FIG. 7 is an explanatory diagram showing a screen display example of a CRT display device in a heading-up mode.

FIG. 8 is an explanatory diagram showing a screen display example of a CRT display device in a north-up mode.

FIG. 9 is an explanatory diagram showing a screen display example according to a modification of the present invention.

FIG. 10 is an explanatory diagram showing a structure of road data in map data.

FIG. 11 is an explanatory diagram of a problem of the conventional method.

[Explanation of symbols]

 1 CD-ROM 2 Operation panel 3 Vehicle position detection unit 4 CRT display device 10 Navigation controller 13 Map image drawing unit 14 Destination setting unit 15 Guided route search unit 16 Guided route memory 17 First V-RAM 18 Second V-RAM 19 Purpose Ground direction calculation part 20 Rotating part

Claims (2)

[Claims] 1. A search for an optimum guide route connecting a starting point to a destination by referring to the map data stored in the map information storage means, storing the guide route data in the guide route memory, and driving. Inside, using the map data and the guide route data while detecting the current location of the vehicle, a map image including the map around the current location of the vehicle and the guide route and the vehicle position mark emphasized on the map is displayed on the screen, In the route guidance method of the in-vehicle navigator that performs a predetermined route guidance from the starting point to the destination, the direction of the starting point or the destination viewed from the current position of the vehicle is calculated while running, regardless of the movement of the vehicle, A route guidance method for an in-vehicle navigator, characterized in that a map image is displayed on a screen while moving so that the direction of departure or the direction of destination is a predetermined fixed direction with respect to the screen. 2. The optimum guide route connecting the starting point to the destination is searched by referring to the map data stored in the map information storage means, the guide route data is stored in the guide route memory, and the vehicle travels. Medium, using the map data and the guide route data while detecting the current position of the vehicle, a map image including the map around the current position of the vehicle and the guide route and the vehicle position mark emphasized on the map are displayed in a plurality of display modes. In the route guidance method of the in-vehicle navigator, which is displayed on the screen in one of the modes selected from the above, and performs a predetermined route guidance from the departure point to the destination, select either the departure point orientation mode or the destination orientation mode. While driving, calculate the direction of the departure point or the destination from the current position of the vehicle, and make sure that the direction of the departure point or the destination direction is a predetermined direction with respect to the screen regardless of the movement of the vehicle. Route guidance method of the in-vehicle navigator, characterized in that, which is adapted to display on the screen while moving the map image.