JPH0763572A - Travel guide image displaying method in on-vehicle navigation system - Google Patents

Abstract

PURPOSE:To extremely easily recognize an intersection to change a route. CONSTITUTION:During travel, a front scene is caught by a video camera 4 installed at a vehicle to project a scenic image on the image plane of a display device 5, and a present position is detected by a vehicle position detecting device 3. A guide object intersection searching part 17 searches a specified guide object intersection existing on a guidance path and frontward in the proceeding direction of a vehicle from the present position of the vehicle and guidance path information stored in a guidance path memory 16. A route guide image describing part 19 calculates an arrow mark diagram showing a route at the guide object intersection, then calculates a center projected image to a specified plane of projection in a sight line coordinate system equivalent to the visual field of the video camera 4, and describes a projected image on a second V-RAM 21. The image of the second V-Ram 21 is synthesized with the scenic image, caught by the video camera 4, by a synthesizing part 23 and displayed on the image plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving guide image display method for a vehicle-mounted navigation device, and more particularly to a driving guide image display method for a vehicle-mounted navigation device suitable for guiding a route from a starting point to a destination.

[0002]

2. Description of the Related Art There is a vehicle-mounted navigation device that guides a vehicle so that a driver can easily reach a desired destination. In this vehicle-mounted navigation device, 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 placed at a predetermined position on the map image. The images are overlaid and drawn, and the images in the V-RAM are converted into video signals and output to the display device for display 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. The information is available at a glance.

The map stored in the CD-ROM is divided into areas of appropriate longitude and latitude widths 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 the road link list RDL as shown in FIG.
T, node list NDLT, intersection data CRDT, of which road link list RDLT
Relates to the road link, data indicating the type of road such as national road, expressway, and other roads, the total number of nodes on the link, and the node list NDLT of each node forming the link
It is composed of the above number and data representing the width of the road between the nodes. 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 data CRDT is a set of numbers on the node list NDLT of the nodes (referred to as intersection composing nodes) closest to the intersection on the link connecting the intersections, for each intersection on the map. The node list NDLT is the map. It is a list of all the above nodes, coordinate information (longitude, latitude) for each node,
It is composed of an intersection identification flag indicating whether the node is an intersection, pointers indicating intersection data if the node is an intersection, pointers indicating a road link to which the node belongs if the node is not the node.

Meanwhile, some vehicle-mounted navigation devices have a route guidance function of performing route guidance from an origin to a destination along an optimum guidance route. In such route guidance, when the driver sets the departure point and the destination before traveling, the simulation calculation such as the Dijkstra method or the horizontal search method is performed by referring to the map data of the CD-ROM to determine the departure point and the destination, for example. The optimum guide route connecting with the shortest distance is obtained, and the guide route data including the node sequence forming the guide route, the leading departure point data and the last destination data is stored in the guide route memory.

[0005] Then, while traveling, a guide route stored in the map display area of the screen is searched for from the node sequence of the guide route memory, and the guide route is displayed in a different color from other roads and displayed in bold. The people try to know which road to drive.

However, when the scale of the map displayed on the screen is large or the road is complicated, it is not possible to simply display the guide route in a color different from that of the other roads and to make it forward in the traveling direction of the vehicle. In some cases, it was not clear in which direction to drive at an existing intersection.

Therefore, during traveling, for example, a left turn, a right turn, etc. at an intersection ahead of the vehicle in the traveling direction on the guide route,
The frontmost guidance target intersection where the traveling direction changes is searched, the distance between the current vehicle position and the guidance target intersection, and the route at the intersection are obtained, and information indicating the distance to the intersection and the route is displayed on the map image of the screen. Or display it in the upper left corner of
It has been proposed to provide information indicating the distance to the intersection and the route by voice.

[0008]

However, even if the distance to the intersection at which the course should be changed is indicated by the display or voice output, the time taken to reach the guidance target intersection greatly changes depending on the traveling speed. It is difficult to intuitively know how far ahead of the vehicle the intersection that should be changed is, especially when there are multiple intersections near the relevant location, at which intersection should the course be changed? I couldn't judge, and sometimes I made a mistake at an intersection where I should change course.

It is therefore an object of the present invention to provide a driving guidance image display method for an on-vehicle navigation device which can correctly recognize at which intersection the route should be changed.

[0010]

According to the present invention, there is provided a video camera for capturing a landscape in front of a vehicle, a display device for displaying a landscape image on a screen, a vehicle position detecting means for detecting a vehicle position, and a vehicle position detecting means. A means for searching a predetermined guidance target intersection existing in the forward direction of the vehicle on the guidance route from the current position and the guidance route information, a means for obtaining a route at the searched guidance target intersection, a vehicle current position, a guidance target intersection A means for specifying the position of the guidance target intersection on the landscape image on the screen by using the coordinates, the installation height and orientation of the video camera, and the optical condition, and a position corresponding to the guidance target intersection on the landscape image. And a means for synthesizing route information at the guidance target intersection.

[0011]

According to the present invention, while traveling, the front scene is captured by the video camera installed in the vehicle to display the scene image on the screen of the image display device, and the current position of the vehicle is detected to detect the current position of the vehicle. A predetermined guidance target intersection existing in the forward direction of the vehicle on the guidance route is searched from the guidance route information and the route at the searched guidance target intersection is obtained, and the current vehicle position, the coordinates of the guidance target intersection, and the video camera The position of the guidance target intersection on the landscape image on the screen is specified using the installation height and orientation and the optical condition, and the route information at the guidance target intersection is set at the location corresponding to the guidance target intersection on the landscape image. To synthesize. As a result, the route information is displayed overlapping the intersection in the image showing the scenery in front of it, so that the driver can intuitively grasp the intersection at which the route should be changed and the route at the intersection. It is possible to easily and accurately recognize an intersection to be performed and a course at the intersection.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device embodying a driving guide image display method according to the present invention. In the figure, 1 is a CD-which serves as a map data storage means.
ROM, 2 is an operation panel, and keys for map search and enlargement / reduction, cross cursor keys including left, right, up, and down keys,
It is provided with a route guidance mode setting key, a departure point setting key, a destination setting key, a start key, and a mode switching key for switching the display mode between the map mode and the landscape mode.
3 is a vehicle position detecting device for detecting the vehicle position and vehicle direction by satellite navigation or self-contained navigation, 4 is a video camera installed horizontally at a predetermined height in front of the vehicle to capture the scenery in front,
Reference numeral 5 denotes a display device, which inputs a video signal to display a map image on a screen together with a cursor mark, a vehicle position mark, an emphasis guide route, and a landscape image captured by a video camera with an arrow indicating a route. Or

Reference numeral 10 denotes a navigation controller having a microcomputer structure, which determines an optimum guide route from a starting point and a destination by simulation calculation such as the Dijkstra method or a lateral search method, or a map image around the vehicle position, if necessary, a cursor. A mark, a vehicle position mark, an emphasized guide route, and the like are displayed on the screen of the display device 5 (in the map mode), or the display device 5 is synthesized while combining the route information with the landscape image in front of the vehicle captured by the video camera 4.
Or on the screen (in landscape mode).

Of these, 11 is a buffer memory for temporarily storing map data read from the CD-ROM 1, and 1
Reference numeral 2 denotes a cursor position calculation unit, which is a longitude corresponding to the center of the map on the screen when a map selecting operation or a cursor operation is performed by using the cross-shaped cursor key of the operation panel 2, a map search key, an enlargement / reduction key, or the like. And the latitude are calculated and output as the cursor position. Reference numeral 13 is a map image drawing unit for CD-R of desired map data (may include peripheral map data) selected by a key for map search, enlargement / reduction, etc. on the operation panel 2.
A map is read from the OM1 to the buffer memory 11 and a map image is drawn on a first V-RAM described later, or a new map is added if necessary as the cursor position data input from the cursor position calculation unit 12 changes in response to a cursor operation. Data from CD-ROM 1 to buffer memory 11
The map image of the first V-RAM is rewritten so that the cursor position is always in the center while reading out to the first V-
Draw a cursor mark in the center of RAM. In addition, the map image drawing unit 13 may add new map data to the CD-R if necessary as the vehicle position data output from the vehicle position detection device 3 changes while the vehicle is traveling (after pressing the start key).
While reading from the OM 1 to the buffer memory 11, the map image of the first V-RAM is rewritten so that the current position is at the center, and the vehicle position mark is set at the center of the first V-RAM based on the vehicle direction data input from the vehicle position detection device 3. Draw in a predetermined direction. Furthermore, in the route guidance mode, from the route data stored in the route memory described later, the route data within the range of the map image currently drawn in the first V-RAM is input, and other route data is input. Draw a guide route that is highlighted in a different color from the road. The first V-RAM has a storage area corresponding to one screen of the display device 5.

Denoted at 14 is a departure point / destination setting section, which is set to a route guidance mode on the operation panel 2 before the start of traveling, and the cursor at the center of the screen is matched with the departure point by the cursor operation on the operation panel 2. When the departure point setting key is pressed, the output of the cursor position calculation unit 12 at that time is set as the departure point data, and after the cursor in the center of the screen is matched with the destination by the cursor operation of the operation panel 2, When the destination setting 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 inputs the start point data and the destination data from the start point / destination setting unit 14 when the setting operation of the start point and the destination is performed in the route guide mode. , A number of map data from the starting point to the destination are read from the CD-ROM 1 to the buffer memory 11, and simulation calculation such as the Dijkstra method or the horizontal search method is performed by referring to the read map data, and for example, the shortest distance is calculated. As an index, an optimum guide route from the starting point to the destination is obtained, and a series of node strings forming the guide route (each node includes the coordinates of longitude and latitude and an intersection identification flag indicating whether or not it is an intersection) Is stored in the guide route memory, which will be described later, as guide route data together with the departure point data and the destination data. Each node in the node string is extracted from the node list of the map data (see NDLT in FIG. 12). When the node forming the guide route is an intersection node, the intersection data CR of the map data
DT, road link list RDLT, node list NDL
With reference to T, all the intersection constituent nodes forming the intersection are read out, and the width data of the road (link) between each intersection constituent node and the intersection is also read out and both are stored in the guide route memory.

Reference numeral 16 is a guide route for storing guide route data.
A node that is a memory and is obtained by the guide route search unit 15.
If the row is, for example, 16 excluding the origin and destination data,
³-When it consists of 2 nodes, as shown on the left side of FIG.
Address F000 of the first storage area_HDeparture day
Stored at address F001_H~ FFFE_HHas
Address F001_HIs closest to the departure point on the guidance route.
Address, address F002 _HNo. 2 on the guidance route to the starting point
Sequential storage of node sequences, such as nodes closer to the eye
To be done. And the last address FFFF_HTo the destination
The data is stored. Stored in the guide route memory 16
The starting point data and the destination data are shown in Fig. 3.
Departure point data is the best for departure point S on the extension of the guide route.
Near pseudo departure node N_sAnd destination data is derived
The pseudo destination node N that is the closest to the destination O on the extension of the route
_OIt is said that In addition, each intersection node in the guide route data
(A node whose intersection identification flag R is 1. Point
T_j2), as shown on the right side of FIG.
In the second storage area of the guide route memory 16, all intersections
Data N of configuration node_j1, N_j2, ... and each intersection configuration
Road width data RD between node and intersection_j1, RD_j2，
.. is memorized.

Numeral 17 is a guidance target intersection searching section for vehicles.
Vehicle position detected by the position detection device 3 and guidance route memory
From the guide route data stored in 16, on the guide route,
Exist in front of the vehicle in the traveling direction (closer to the destination than the vehicle position)
Changes in driving directions other than straight, such as right and left turns, at intersections
The intersection in the foreground is the one at the forefront of guidance.
And specify. Specifically, the vehicle traveling direction on the guidance route
For each of the intersections in the front, intersect from the front side in order
Point node to N_a, In the sequence of nodes that make up the
Code N_aThe node with the address one before the intrusion node
N_b, N_aThe node whose address is one after
_cAs shown in FIG. 4, the intersection node N _aCentered around
Intrusion node N_bAnd intersection node N_aInvades the straight line connecting
Incoming node N_bA straight line extending to the side opposite to
Then, the range that makes an angle of 30 ° from the reference direction A
Escape node N_cWhen there is a
Judge and exit node N to the other range_cExists
If it is determined that there is a change in the traveling direction, the traveling direction changes first.
The intersection that has been determined to be a destination is the guidance target intersection.

Reference numeral 18 denotes a distance calculation unit, which calculates the distance between the vehicle position and the guidance target intersection. The distance calculation unit 18
Calculates a positive distance when the guidance target intersection is in front of the vehicle, and a negative distance when the guidance target intersection comes behind the vehicle. Reference numeral 19 denotes a route guidance image drawing unit that, when the distance between the vehicle position and the guidance target intersection is within a certain distance (within this embodiment, within 250 m as an example), vehicle position data, vehicle direction data, guide route data, Using the intersection configuration node data and road width data, the current position is set as the origin, and on the plane where the vehicle azimuth direction and the direction orthogonal to this are the coordinate axes, the shape of the intersection is set to follow the shape of the guidance target intersection. Calculate the shape of the arrow that indicates the path. Then, the arrow figure indicating the path is placed on a plane that is a certain distance below the viewpoint in the line-of-sight coordinate system, and the image of the arrow figure that is centrally projected in the window of the projection surface placed at a predetermined position immediately in front of the viewpoint is displayed. Calculate and draw the projected image in the second V-RAM. That is, the same image as that captured by the video camera 4 on the arrow figure placed along the actual guidance target intersection in front of the vehicle is drawn in the second V-RAM. The second V-RAM has a storage area corresponding to one screen of the display device 5.

Here, how to obtain the central projection image of the arrow figure showing the course will be described. Assuming that the guidance target intersection node is P _a and that there are five intersection constituent nodes P _{b to} P _f that compose the intersection, if the ingress node is P _b and the escape node is P _c , the ingress node is first The path is obtained as a line segment that sequentially connects P _b , the guidance target intersection node P _a , and the escape node P _c . Therefore, as shown in FIG. 5, while performing a predetermined coordinate conversion, the current position is set as the origin, the vehicle azimuth direction is the z-axis,
Position P of the guidance target intersection, the entry node, and the exit node on the XZ plane with the direction orthogonal to this as the x axis
_a (x _a , z _a ), P _b (x _b , z _b ), P _c (x _c ,
z _c ) is _calculated . In FIG. 5, for simplicity, the vehicle azimuth direction is made to coincide with the direction of the straight line connecting P _b and P _a .
Next, a point Q ₁ separated by a certain distance L from P _{a in the} P _b direction
When obtains the position of the P _c direction points separated by L Q ₂ from P _a, further, only from Q ₁ half of the width W _b of the road between ingress nodes P _b and P _a, the P _b and P _a From a point Q ₃ which is separated from the connecting straight line to the left in the left direction, and Q _{2 which} is half the width W _c of the road between the escape nodes P _c and P _a , and is perpendicular to the straight line connecting P _a and P _c. The position of the point Q ₄ distant in the direction is obtained.
Then, the position of the intersection Q ₅ of the straight line drawn from Q ₃ in parallel with the straight line connecting P _b and P _a and the position of the intersection Q ₅ of the straight line drawn from Q ₄ in parallel with the straight line connecting P _a and P _c are obtained. Line segment Q ₂
-Q ₄ is a part of the base, the position of each vertex Q ₆ to Q ₈ of a predetermined size of the equilateral triangle tip is to come to the opposite side of the P _a as seen from the line segment Q ₂ -Q ₄ Ask for. Thus obtained P _a , Q ₁ , Q ₃ , Q ₅ , Q ₄ , Q ₆ ,
By connecting Q ₇ , Q ₈ , Q ₂ , and P _a in order, an arrow figure indicating the route at the guidance target intersection can be obtained.

Next, as shown in FIG.
The dimension is moved to the x ', y', z'line-of-sight coordinate system (the positive direction of the z'axis is the line-of-sight direction, and the origin O is the viewpoint position).
In other words, the points _{P a, Q 1, Q 3} , Q 5, Q 4, Q 6,
For two-dimensional coordinates (x, z) of Q ₇ , Q ₈ , and Q ₂ , three-dimensional coordinates (x ', z', y ') can be obtained by setting x' = x z '= z y' =-h. Convert to. As a result, the arrow figure indicating the route can be placed in the plane below the viewpoint in the line-of-sight coordinate system by a certain distance.
Then, each point forming the arrow figure on the line-of-sight coordinate system is further center-projected onto the projection plane vertically placed at the position of z '= k, and X'and Y'are obtained to obtain the projected image. Calculate. Then, the projection image within the range of the predetermined window WD corresponding to the visual field range of the video camera 4 on the projection surface is
Drawing in the second V-RAM (the inside of the arrow figure is filled with a specific color, for example, red). At this time, the second V-RAM
The projected image is drawn so that the entire storage area of the above corresponds to the entire range of the window WD. X'and Y'can be calculated by X '= kx' / z 'Y' =-kh / z '. Here, h is the installation height of the video camera 4. Also, the window WD
Has the same aspect ratio as the screen of the display device 5. k
Is the optical conditions of the video camera 4 (viewing angle, focal length, etc.)
And the size of the window WD, the video camera 4
So that the scene in the front is captured and the same field of view as when looking into the window WD from the viewpoint.

Since the field of view looking into the window from the viewpoint in the line-of-sight coordinate system is equivalent to the field of view of the actual landscape captured by the video camera 4, P on the three-dimensional coordinates (x ', z', y ') _The image P _a ′ obtained by projecting _a in the window identifies the position corresponding to the guidance target intersection on the landscape image captured by the video camera 4. When the video camera 4 is installed in a direction other than the horizontal direction, the projection plane may be tilted accordingly and the calculation may be performed. The size of the window WD can be set to any size because it can be associated with the size of one screen relatively.
Is made smaller, and k is made larger when the window is made larger.

Returning to FIG. 1, reference numeral 20 denotes a first V-RAM, which is a map image drawn by the map image drawing unit 13 (including a cursor mark when the cursor is operated, and a vehicle position mark when traveling in the route guidance mode. And other thick roads, which have different colors from other roads). 21 is the second V-RA
M, and stores the arrow graphic image drawn by the route guidance image drawing unit 19. First V-RAM 20 and second V-RA
Each M21 has a storage area for one screen of the display device 5. Reference numeral 22 denotes a conversion unit that reads out the image drawn in the first V-RAM 20 while scanning and converts the image into an analog video signal, and 23 synthesizes the image drawn in the second V-RAM 21 with the landscape image captured by the video camera 4. And outputs the analog video signal. Reference numeral 24 denotes a changeover switch that can be switched between the conversion unit 22 side and the landscape mode combination unit 23 side in the map mode, and the output side of the switch is connected to the display device 5.

7 to 9 are flow charts showing the operation of the navigation controller 10, FIG. 10 is an explanatory view showing the outline of the road around the departure place, and FIG. 11 is an explanatory view of a screen display example of the display device 5. , Will be described with reference to these figures. Note that both the flag A indicating that the guidance target intersection has been searched and the flag B indicating that the route guidance image is being displayed are both set to 0 in advance. Further, it is assumed that the display mode is the map mode and the switch 24 is switched to the conversion unit 22 side.

First, when a map search operation of the operation panel 2 and an operation of a key for enlarging / reducing a selection of a map of a desired area at a desired scale are performed, the map image drawing unit 13 causes the desired map from the CD-ROM 1. The data is read into the buffer memory 11 and a map image is drawn on the first V-RAM 20. The map image drawn on the first V-RAM 20 is read by the conversion unit 22, converted into an analog video signal, and output to the display device 5. The display device 5 displays a map on the screen based on the input video signal (steps 101 and 102 in FIG. 7). Next, operation panel 2
When the route guidance mode setting operation is performed, the navigation controller 10 sets the route guidance mode (steps 103 and 104). When the cross cursor key on the operation panel 2 is operated, the cursor position calculation unit 12 calculates the cursor position (coordinates of longitude and latitude) (step 10
5, 106), the map image drawing unit 13 reads the predetermined map data from the CD-ROM 1 to the buffer memory 11 according to the change of the cursor position, and then the first V-RAM 20.
Then, the map image is drawn so that the center is always at the cursor position, and the cursor mark is drawn in the center of the first V-RAM 20. As a result, the map on the screen moves in accordance with the cursor operation while the cursor mark is displayed in the center of the screen (steps 107 and 108).

When the cursor mark on the screen reaches the destination, the cursor operation is temporarily stopped and the destination setting key of the operation panel 2 is pressed. The cursor position data output from is set and registered as destination data (steps 109 and 110). Next, perform the cursor operation again to move the map on the screen. When the cursor mark reaches the departure point, stop the cursor operation once and press the departure point setting key on the operation panel 2 to set the departure point / destination Part 1
4 sets and registers the cursor position data output from the cursor position calculation unit 12 at that time as the departure point data (steps 111 and 112).

In this way, when the setting / registration of the departure point data and the destination data is completed (YES in step 113).
S) Based on the starting point data and the destination point data, the guide route searching unit 15 reads the map data from the starting point to the destination point from the CD-ROM 1 to the buffer memory 11 and performs simulation calculation such as the Dijkstra method or the horizontal search method. , For example, searching for an optimal guide route using the shortest distance as an index, and a series of nodes forming the guide route is used as the starting point data (here, node N _s , see FIG. 3) and the last destination. data (here nodes N _O, see FIG. 3) is stored in address order in the first storage area of the navigation route memory 16 (step 113, step 201 and 202 in FIG. 8). When there are 16 ³ -2 nodes (excluding the departure point data and the destination data) forming the guide route, the contents of the first storage area of the guide route memory 16 are as shown in FIG.
It becomes like the left side of.

The guide route search unit 15 sets the intersection identification flag R in the node data of the guide route memory 16 for the intersections in the node sequence forming the guide route, and sets the second pointer indicated by the pointer T _j . At a predetermined location in the storage area,
The intersection constituent nodes N _j1 , N _j2 , ... Read by referring to the intersection data CRDT of the map data, the road link list RDLT, and the node list NDLT, and the road width data RD _j1 , RD between each intersection constituent node and the intersection. _j2 , _...
・ Store. The contents of the second storage area are as shown on the right side of FIG.

Next, when the start key is pressed on the operation panel 2, the map image drawing unit 13 inputs the current vehicle position data (starting point) and the vehicle direction data from the vehicle position detecting device 3, and the map data around the starting point. Is read from the CD-ROM 1 to the buffer memory 11, and a map image is drawn on the first V-RAM 20 so that the starting point is in the center (steps 203 and 204). Then, the map image drawing unit 13
Reads out the nodes in the map display area of the screen from the guide route data stored in the guide route memory 16, and based on these data, guides the route to the first V-RAM 20 in a color different from that of other roads and thickly. The enhanced guidance route for the vehicle is drawn (step 205), and the vehicle position mark with the vehicle azimuth direction oriented in the center of the first V-RAM 20 is drawn (step 206). As a result, the map around the departure place with the vehicle position mark on the departure point in the center is displayed on the screen,
Further, since the guide route is displayed thicker in a different color from the other roads on the screen, it is possible to know at a glance which road should be traveled (see FIG. 11 (1)).

When the vehicle starts traveling, the vehicle position detecting device 3 sequentially detects the vehicle position and the vehicle direction, and outputs the vehicle position data and the vehicle direction data. When the map image drawing unit 13 inputs the vehicle position data and the vehicle direction data, the CD-RO
While reading the predetermined map data including the vehicle position data from M1 into the buffer memory 11, a map image is drawn on the first V-RAM 20 so that the vehicle position is at the center (steps 207 and 208). Then, of the guide route data stored in the guide route memory 16, the node included in the map display area of the screen is read out, and based on these data, the first V-RAM 2 that is thicker in a color different from that of other roads is read.
The emphasis guidance route is drawn on 0 (step 209),
A vehicle position mark is drawn in the center of the first V-RAM 20 in the direction indicated by the vehicle direction (step 210). As a result,
As the vehicle travels, the map on the screen moves so that the center is always at the vehicle position.

On the other hand, first, the flag A indicating that the guidance target intersection has been searched is 0 (step 301 in FIG. 9).
YES), the guidance target intersection searching unit 17 that has input the vehicle position data refers to the guide route data stored in the guide route memory 16 and is the frontmost in front of the vehicle when viewed from the vehicle position on the guide route. For each of the intersection nodes at, the positional relationship between the preceding ingress node, the relevant intersection node, and the subsequent exit node is determined as shown in FIG. Repeating the process of determining whether the traveling direction changes for the next intersection on the guide route, the intersection that changes the traveling direction at the position closest to the vehicle position is determined and is set as the guidance target intersection. (Step 302). Here, the CP of FIG.
_It is assumed that ₁ is the first guidance target intersection. Then, a flag A indicating that the guidance target intersection has been searched
(Step 303).

Next, the distance calculation unit 18 refers to the guide route data in the guide route memory 16 and the distance K along the guide route between the current vehicle position and the guide target intersection obtained by the guide target intersection search unit 17. Is calculated (step 30)
4). In addition, when the vehicle position comes to a position ahead of the guidance target intersection, K becomes negative. Then, the flag B indicating that the route guidance image is being displayed is 0 (YES in step 305).
S), the route guidance image drawing unit 19 determines whether the distance between the vehicle position and the guidance target intersection is within 250 (m) (step 3).
06), if NO, the route guidance image is not drawn, the flag B indicating that the route guidance image is being displayed is left at 0, and the process returns to step 207 of FIG. 8 to obtain the next vehicle position data from the vehicle position detection device 3. By inputting the vehicle direction data, the map is moved according to the change of the vehicle position, and the vehicle position mark and the emphasis guidance route are rewritten (steps 208 to 210).

Since the guidance target intersection has already been searched (NO in step 301 of FIG. 9), the distance calculation unit 18 calculates the distance K along the guide route between the new vehicle position and the guidance target intersection (step 304), and since the route guidance image is not yet displayed (YE in step 305)
S), the route guidance image drawing unit 19 has a distance K of 250 (m)
It is determined whether it is below (step 306). Here, if YES, B = 1 is set (step 307),
Referring to the vehicle position data and the vehicle direction data input from the vehicle position detection device 3, the guide route data stored in the guide route memory 16, the intersection constituent node, and the road width data, for the guidance target intersection CP ₁ of this time, By the method shown in FIG. 5, an arrow figure indicating the route at the intersection is calculated (step 308).

Then, by the method shown in FIG. 6, an arrow figure having a width is placed at a position k in front of the viewpoint by placing it on a plane below the viewpoint by a certain distance h in the x ', y', z'line-of-sight coordinate system. An image center-projected on the projection surface is calculated (step 30).
9). Then, the projection image is drawn on the second V-RAM 21 while cutting out a certain range of the projection surface, a combining command is output to the combining unit 23, and the route guidance image drawn on the second V-RAM 21 is captured by the video camera 4. It is output as an analog video signal while being combined with the landscape image (step 31).
0). Here, when the driver switches the display mode of the screen to the landscape mode, the switch 24 is switched to the synthesizing unit 23 side, so that the screen above the guidance target intersection CP _{1 in} the landscape image captured by the video camera 4 is displayed. The arrow figure that has just been superimposed on is displayed three-dimensionally (steps 311, 3).
12, see FIG. 11 (2)).

After the processing of step 312, the navigation controller 10 returns to step 207 of FIG. 8 and inputs the next vehicle position data and vehicle direction data from the vehicle position detecting device 3 to move the map according to the change of the vehicle position. , The vehicle position mark and the emphasis guide route are rewritten (steps 208 to 210). Since the guidance target intersection has already been searched (YES in step 301 of FIG. 9), the distance calculation unit 18 calculates the distance along the guide route between the new vehicle position and the guidance target intersection CP ₁ (step 304). , Furthermore, since the route guidance image is being displayed (N in step 305
O), the route guidance image drawing unit 19 determines whether the distance K is negative (step 313). If NO, the vehicle position data and the vehicle direction data input from the vehicle position detection device 3 are stored in the guide route memory 16. With reference to the guide route data, the intersection constituent nodes, and the road width data, the arrow graphic indicating the route at the intersection is calculated for the guidance target intersection CP ₁ of this time by the method shown in FIG. 5 (step 30).
8).

Then, by the method shown in FIG. 6, the arrow figure having a width is placed on the plane below the viewpoint by a certain distance h in the x ', y', z'line-of-sight coordinate system and is at the position in front of the viewpoint k. An image center-projected on the projection surface is calculated (step 30).
9). Then, the projection image is drawn on the second V-RAM 21 while cutting out a certain range of the projection surface, a combining command is output to the combining unit 23, and the route guidance image drawn on the second V-RAM 21 is captured by the video camera 4. It is output as an analog video signal while being combined with the landscape image (step 31).
0). As a result, the arrow figure on the screen looks a little closer to the guidance target intersection.

Similarly, as the distance between the vehicle position and the guidance target intersection CP ₁ changes, the three-dimensionally drawn arrow figures on the screen are successively approached together with the guidance target intersection. Change. Initially, when the vehicle position is away from the guidance target intersection, the guidance target intersection in the landscape image seems to be small and far upward (FIG. 11).
(Refer to (2)), as the vehicle position approaches the guidance target intersection, the guidance target intersection in the landscape image gradually moves downward and becomes larger, and it seems that it approaches the front side (see FIG. 11 (3)). ). Therefore, the driver sees the arrow figure as if it were placed on the guidance target intersection along the actual guidance target intersection, so at any time, at a glance at the screen, change the route at which intersection. It is possible to intuitively grasp whether it should be done, and it is possible to accurately change the course toward the destination at the guidance target intersection.

When the vehicle turns the guidance target intersection CP ₁ along the guidance route, the distance K between the vehicle position and the guidance target intersection (CP ₁ ) calculated by the distance calculation unit 18 becomes negative, so that the route guidance image is displayed. The drawing unit 19 determines YES in step 313 of FIG. 9, outputs a combining stop command to the combining unit 23 to temporarily stop the combining operation, and outputs only the landscape image captured by the video camera 4 to the display device 5, and the screen is displayed. Only the landscape image is displayed on the screen (step 314). Then, the flags A and B are cleared (step 315).

After that, when it comes to step 301 in FIG. 9, the guidance target intersection searching unit 17 determines YES, and the guidance target intersection where the vehicle should change the traveling direction next to the intersection CP ₁ (step 302, FIG. 10 CP ₂ ) are searched. Then, when the distance calculation unit 18 calculates the distance K between the vehicle position and the guidance target intersection (step 304) and the distance is within 250 m (YES in step 306), the route guidance image drawing unit 19 causes the guidance target intersection CP to be displayed. _The arrow shape indicating the course in ₂ is calculated (step 308), and the three-dimensionally drawn arrow figure is synthesized and displayed on the landscape image (step 3).
09, 310), and as the vehicle position changes, the arrow figure images are sequentially redrawn so that the arrow figures on the screen seem to come closer to the front (steps 301, 304-3).
Repeat 10).

When the driver follows the guidance on the screen and passes through the _second guidance target intersection CP ₂ , the arrow figure in the landscape image temporarily disappears, and then the route guidance of the third guidance target intersection. Is displayed. Therefore, the destination can be surely reached by simply following the arrow on the screen. In addition, when it is desired to return the display mode to the map mode, the switch 24 is switched to the conversion unit 22 side by performing a switching operation to the map mode on the operation panel 2.
Since the map around the vehicle position is displayed on the screen together with the emphasized guidance route and the vehicle position mark, it is possible to confirm where the vehicle is currently traveling (steps 311 and 312 in FIG. 9).

According to this embodiment, since the arrow figure is superimposed on the position of the guidance target intersection in the scenery image in front of the vehicle captured by the video camera 4, the route at the guidance target intersection is displayed. It is possible to intuitively grasp at a glance at which intersection and in which direction the course should be changed by comparing it with the scenery. Further, since the arrow figure having a width half the width of the road is displayed three-dimensionally by the central projection, it is possible to see the arrow which is not unnatural with the landscape image.
Further, since the display mode can be switched between the map mode and the landscape mode, it is possible to receive the route guidance in the mode preferred by the driver.

The display of the route information at the guidance target intersection is performed by an arrow figure having a width half the width of the road overlapped with the guidance target intersection in the landscape image, or by an arrow figure having a certain width. , A narrow arrow shape, an arrow shape with the same width as the road width, a polygonal line shape without the triangle at the tip of the arrow shape, or a "left turn",
You may make it a character such as "turn right". In addition, the guidance target intersection, regardless of whether the traveling direction changes,
On the guide route, it may be the frontmost intersection existing in the forward direction of the vehicle. Further, a landscape image including route information such as an arrow graphic may be combined with a part of the map image including the emphasized guide route and the vehicle position mark and displayed on the screen. The video camera may be installed in any place where the scenery in front of the vehicle can be captured, such as in the middle of the vehicle or directly above the driver's seat, and the orientation of the video camera may be slightly downward from the horizontal (in this case, , The projection plane in FIG. 6 may be tilted so as to be perpendicular to the optical axis of the video camera). In addition, the distance between the vehicle position and the guidance target intersection is 25
You may make it synthesize | combine the figure etc. which show a course even if it is larger than 0 m to a landscape image.

[0043]

As described above, according to the present invention, while traveling, a video camera installed in the vehicle captures the scenery in front of the vehicle, displays a scenery image on the screen of the image display device, and detects the current position of the vehicle. A search for a predetermined guidance target intersection existing in the forward direction of the vehicle on the guidance route from the current position and the guidance route information, and the route at the searched guidance target intersection is obtained, and the current vehicle position and the coordinates of the guidance target intersection, The position of the guidance target intersection on the landscape image of the screen is specified by using the installation height and orientation of the video camera and the optical condition, and the position of the guidance target intersection on the landscape image is identified at the guidance target intersection. Since it is configured to synthesize route information,
Since the route information is displayed overlapping the intersection in the image showing the scenery in front as it is, the driver can intuitively grasp the intersection to change the route and the route at the intersection, and the intersection to change the route. And the course at the intersection is easy, and
Can be accurately recognized.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device that embodies a driving guide image display method according to the present invention.

FIG. 2 is an explanatory diagram of data stored in a guide route memory.

FIG. 3 is an explanatory diagram of departure point data and destination data stored in a guide route memory.

FIG. 4 is an explanatory diagram showing a method of detecting an intersection where a traveling direction changes.

FIG. 5 is an explanatory diagram of a method of calculating an arrow figure indicating a route at a guidance target intersection.

FIG. 6 is an explanatory diagram of a method of calculating a three-dimensional center projection image of an arrow figure.

FIG. 7 shows a first operation of the navigation controller.
2 is a flowchart of.

FIG. 8 is a second diagram showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 9 is a third view showing the operation of the navigation controller.
2 is a flowchart of.

FIG. 10 is an explanatory diagram showing an outline of roads around a departure place.

FIG. 11 is an explanatory diagram illustrating a screen display example of a display device.

FIG. 12 is an explanatory diagram showing a structure of road data in map data.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CD-ROM 3 Vehicle position detection device 4 Video camera 5 Display device 10 Navigation controller 15 Guidance route search unit 16 Guidance route memory 17 Guidance target intersection search unit 18 Distance calculation unit 19 Route guidance image drawing unit 21 Second V-RAM 23 Composite Department

Claims (1)

[Claims] 1. While traveling, a front view is captured by a video camera installed in the vehicle, a landscape image is displayed on the screen of the display device, and the current position of the vehicle is detected. Based on the current position of the vehicle and guidance route information. A predetermined guidance target intersection existing in the forward direction of the vehicle on the guidance route is searched, and the route at the searched guidance target intersection is obtained, and the current vehicle position, coordinates of the guidance target intersection, installation height and direction of the video camera, and The position of the guidance target intersection on the landscape image on the screen is specified using the optical condition, and the route information at the guidance target intersection is combined with the location of the guidance target intersection on the landscape image, A method for displaying a driving guidance image of a vehicle-mounted navigation device, comprising: