JPH07262492A - On-vehicle navigator - Google Patents

Abstract

PURPOSE:To rightly recognize at which intersection a course should be changed at a glance. CONSTITUTION:When the setting operations of a departure place and a destination place are performed on an operation panel 4, a route search part 15 searches the optimal guidance route between the departure place the destination place by using the map data of a CD-ROM 1 and the route is stored in a guidance route memory 16. During a running, a vehicle location detector 3 detects the present location and a guide object/course specifying part 17 specifies prescribed guide object intersection and course existing in the front of the vehicle on the guidance route from the present location of the vehicle and guidance route data on occasion. A course guide image plotting part 20 calculates an arrow graphic showing the course at a guide object intersection, calculates the center projected image to the plane which is the same as the image surface of a virtual image reflected and projected on a front glass by a first display device 5 in a gaze coordinate system which is equivalent to the visual field of a driver and plots the projected image on a second V-RAM 22. The course guide image of the second V-RAM 22 is displayed to the driver by overlapping the image with a landscape by the first display device 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted navigation device, and more particularly to 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. Then, while the vehicle is traveling, the driver can search for a guide route in the map display area of the screen from the node sequence of the guide route memory and display the guide route in a color different from other roads so that the driver can I try to know if I should drive on the road.

However, when the scale of the map displayed on the screen is large or the roads are complicated, it is possible that the guide route is displayed in a color different from those of other roads and is thicker than that of the other roads. In some cases, it was not clear in which direction to drive at an existing intersection. Therefore, while traveling, a search is made for the forefront guidance target intersection where the traveling direction changes, such as a left turn or a right turn, among the intersections in the forward direction of the vehicle on the guide route, and the current vehicle position-guidance target The distance between the intersections and the route at the intersections are obtained, and the information indicating the distances and the routes to the intersections is synthesized and displayed on the upper left of the map image on the screen, or the information indicating the distances and the routes to the intersections is voiced. There are proposals to be provided in.

[0006]

However, even if the distance to the intersection at which the course should be changed is indicated by the synthetic display on the map image or the voice output, the time required to reach the guidance target intersection depends on the traveling speed. Because it changes significantly, it is difficult to intuitively grasp how far ahead the intersection where the traveling direction should be changed is ahead of the vehicle, it takes time until the intersection where the course should be changed is known, and there are multiple intersections near the relevant place. When they were close to each other, it was impossible to determine at which intersection the course should be changed, and there was a case where the wrong intersection was changed. In view of the above, an object of the present invention is to provide a vehicle-mounted navigation device capable of correctly recognizing at which intersection the course should be changed.

[0007]

According to the present invention, there is provided a map information storage means for storing map data, a vehicle position detection means for detecting a vehicle position, and a windshield for reflecting light to a driver. Display means that allows the route guidance image to be seen on top of the front landscape, search means that searches the optimal guidance route connecting the departure point and destination with reference to the map data, and the guidance that is searched by the route search means. Guide route storage means for storing route information, and a predetermined guide target intersection existing ahead of the vehicle on the guide route based on the current position of the vehicle and the guide route information, and a guide target / route for obtaining a route at the guide target intersection. The position of the actual guidance target intersection seen by the driver from the identification means, the current position of the vehicle, the position and route of the guidance target intersection, the driver's viewpoint, and the position of the image plane of the route guidance image displayed by the display means. And route guidance image drawing means for drawing the route guidance image at the guidance target intersection so that the positions of the guidance target intersections on the image plane of the route guidance image overlap with each other and displaying the image on the display means. It

[0008]

According to the present invention, the optimum guidance route connecting the starting point and the destination is searched with reference to the map data and stored. During traveling, the vehicle position is detected, and a predetermined guidance target intersection existing ahead of the vehicle on the guidance route along the guidance route information and a route at the guidance target intersection are obtained from the current position of the vehicle and the guidance route information. Then, from the current position of the vehicle, the position and route of the guidance target intersection, the driver's viewpoint, the position of the image plane of the route guidance image by the display means, the position of the actual guidance target intersection and the image of the route guidance image seen by the driver. The route guidance image at the guidance target intersection is drawn so that the positions of the guidance target intersection on the plane overlap each other, and is displayed on the display means. As a result, the route guidance image can be viewed by superimposing it on the intersection in the landscape ahead of which the route should be changed. It is possible to grasp the course in the road, the wrong course does not occur, and safe driving is possible.

The driver's viewpoint is measured by the measuring means. As a result, the actual position of the guidance target intersection seen by the driver and the position of the guidance target intersection on the route guidance image surface can be accurately overlapped.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device according to an embodiment of the present invention. In the figure, 1 is a CD-ROM which serves as map data storage means, 2 is an operation panel, keys for map search and enlargement / reduction, cross cursor keys including left, right, up and down keys, route guidance mode setting Key, origin setting key, destination setting key, start key,
And so on. 3 is a vehicle position detecting device that detects the vehicle position and vehicle direction by satellite navigation or self-contained navigation, 4 is a distance sensor that is installed on the ceiling above the driver's seat and measures the distance between the driver's top, and 5 is the windshield A first display device 6 that reflects light to the driver so that the driver can see the route guidance image in a manner that overlaps with the forward scenery. The second display device 6 displays a map image together with a cursor mark, a vehicle position mark, an emphasis guidance route, and the like. It is a display device. 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 such as Dijkstra's method or horizontal search method, and a map image around the vehicle position, a cursor mark, a vehicle if necessary. It is displayed on the screen of the second display device 6 together with the position mark, the emphasis guide route, etc., or the route guidance image is displayed on the first display device 5.

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 second display device 6.

Reference numeral 14 denotes 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 after the cursor operation on the operation panel 2 causes the cursor at the center of the screen to coincide with the departure point. 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 route search unit, which inputs the departure point data and the destination data from the departure point / destination setting unit 14 when the setting operation of the departure point and the destination is performed in the route guidance 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 used as an index. As, the optimum guidance route from the departure place to the destination is obtained, and a series of node strings that compose the guidance route (each node includes the coordinates of longitude and latitude and the intersection identification flag indicating whether or not it is an intersection) It 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. 14). When the node forming the guide route is an intersection node, the intersection data CRD of the map data
T, road link list RDLT, node list NDLT
With reference to, all the intersection constituent nodes that make up 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 data and the 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.

Reference numeral 17 is a guidance target / route specifying unit for the vehicle.
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 identify the route information at the guidance target intersection.
Meru. Specifically, the vehicle is located ahead of the vehicle traveling direction on the guidance route.
For each existing intersection, from the front side, the intersection node
To N_a, Node N in the sequence of nodes forming the guide route_a
The node of the address one before the intrusion node N_b, N_aof
Exit the node with the next address node N_cAs a figure
As shown in 4, the intersection node N_aWith no intrusion
De N_bAnd intersection node N_aEnter the straight line connecting_b
With the straight line extending to the opposite side as the reference direction A,
Escape node N within the range of 30 ° from direction A_cBut
If it exists, it is determined that the driving direction has not changed, and other
Escape node N to range_cWhen there is a change in running direction
Crossing that was judged to have changed and that there was a change in the driving direction first
The point is the guidance target intersection. Course information at the target intersection
Informing node N _b, Intersection node N_a, Escape node
N_cIs required as a combination of.

Reference numeral 18 denotes a first distance calculation unit, which is the vehicle position.
(Here, it is the same as the driver's position.)-Guided intersection
Calculate the distance between. The first distance calculator 18 will guide you.
When the target intersection is in front of the vehicle, the distance is calculated positively,
When the target intersection is behind a vehicle, the distance is calculated negatively
To do. Reference numeral 19 denotes a second distance calculation unit, which is used in the distance sensor 4.
Measure the height from the ground to the driver's viewpoint using the detection distance.
Calculate Specifically, the height from the ground to the distance sensor 4
h₀, Distance to the crown measured by the distance sensor 4 h ₁, Mark
Distance h from the top of the head to the normal adult h₂Than,
The height h from the ground to the driver's point of view is the following equation, h = h₀-H₁-H₂ (See FIG. 5).

Reference numeral 20 denotes a route guidance image drawing unit, which makes the position of the actual guidance subject intersection visible to the driver and the position of the guidance subject intersection on the image plane of the route guidance image overlap each other. Draw a route guidance image. That is, when the distance between the vehicle position and the guidance target intersection is within a certain distance (within this embodiment, as an example, within 250 m), the vehicle position data, the vehicle orientation data, the position and route information of the guidance target intersection, the guidance target intersection Using the intersection configuration nodes and the width data of the roads between the nodes, the current position is set as the origin and the shape of the guidance target intersection is set on the horizontal plane with the vehicle azimuth direction and the direction orthogonal to this as the coordinate axis. The shape of the arrow indicating the route at the intersection is calculated. Then, the arrow figure indicating the path is placed on a horizontal plane that is a certain distance h below the viewpoint in the line-of-sight coordinate system, and the arrow figure of the arrow figure that is centrally projected in the window of the projection plane placed at a predetermined position immediately in front of the viewpoint is displayed. The image is calculated, and the projected image is set to the second V-RA.
Draw on M. The projection surface is flush with the image plane of the route guidance image of the first display device 5 formed by reflecting light on the windshield, and the window is the region of the route guidance image on the image plane. For the sake of simplicity in this embodiment, as shown in FIG. 5, the image plane of the route guide image (virtual image) of the first display device 5 formed by reflecting the light on the windshield FG is vertically in front of the viewpoint by a distance k. Face.

Here, how to obtain the central projection image of the arrow figure showing the route 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 _e , first the ingress node 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 _e . Therefore, as shown in FIG. 6, while the predetermined coordinate conversion is performed, the current position is set as the origin, the vehicle azimuth direction is the z-axis,
Position P of the guidance target intersection, entry node, and exit node on the XZ horizontal plane with the direction orthogonal to this as the x axis
_a (x _a , z _a ), P _b (x _b , z _b ), P _e (x _e ,
z _e ) is calculated. In FIG. 6, for simplification, the vehicle azimuth direction is aligned 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 P _e direction by L distant point 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 the point Q ₃ that is separated from the connecting line to the left in the left direction and the half Q ₂ of the width W _e of the road between the escape nodes P _e and P _a , the line that connects P _a and P _e is perpendicular to the left. The position of the point Q ₄ distant in the direction is obtained.
Then, the position of the intersection point 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 point Q ₅ of the straight line drawn from Q ₄ in parallel with the straight line connecting P _a and _Pe 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.
Dimension x ′, y ′, z ′ is moved onto the 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 path can be placed in the horizontal plane below the viewpoint by a certain distance h in the line-of-sight coordinate system. Then, each point forming the arrow figure on the line-of-sight coordinate system is further center-projected onto the projection plane V vertically placed at the position of z ′ = k, thereby obtaining X ′ and Y ′. Perform image calculations. Then, a projection image within the range of the window WD corresponding to the area of the route guidance image on the projection surface V is drawn in the second V-RAM (the inside of the arrow figure is a specific color,
For example, paint in red). X ′ and Y ′ can be obtained by calculation as X ′ = kx ′ / z ′ Y ′ = − kh / z ′.

The position P _{a of} the actual guidance target intersection seen from the viewpoint in the line-of-sight coordinate system and the position P _a ′ of the guidance target intersection in the route guidance image overlap. When the image plane and the area of the route guidance image reflected on the windshield are located at other positions, the projection plane and the window may be changed accordingly.

Returning to FIG. 1, reference numeral 21 denotes a first V-RAM, which is a map image drawn by the map image drawing unit 13 (including a cursor mark when operating the cursor, and a vehicle position mark when traveling in the route guidance mode). And other thick roads, which have different colors from other roads). 22 is the second V-RA
M, which stores the arrow graphic image drawn by the route guidance image drawing unit 20. First V-RAM 21 and second V-RA
M22 has a storage area for one screen of each of the second display device 6 and the second display device 5. Reference numeral 23 is a conversion unit that reads out an image drawn in the first V-RAM 21 while scanning and converts it into an analog video signal and outputs it to the second display device 6, and 24 is a second V-RAM.
The first display device 5 converts the image drawn on the display 22 while scanning and reads the image, and converts the image into an analog video signal.
Is a conversion unit for outputting to.

8 to 10 are flow charts showing the operation of the navigation controller 10, FIG. 11 is an explanatory view showing the outline of the road around the departure place, and FIG. 12 is the second display device 6.
FIG. 13 is an explanatory view of a screen display example of FIG. 13, and FIG. 13 is an explanatory view of a landscape and a route guidance image that are in the driver's visual field. It is assumed that both the flag A indicating that the guidance target intersection / route has been specified and the flag B indicating that the route guidance image is being displayed have been set to 0 in advance.

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 to the buffer memory 11 and the map image is drawn on the first V-RAM 21. The map image drawn in the first V-RAM 21 is read by the conversion unit 23, converted into an analog video signal, and output to the second display device 6. The second display device 6 displays a map on the screen based on the input video signal (steps 101 and 102 in FIG. 8). continue,
When the route guidance mode is set on the operation panel 2, 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 1
2 calculates the cursor position (coordinates of longitude and latitude) (steps 105 and 106), and the map image drawing unit 13 reads the predetermined map data from the CD-ROM 1 into the buffer memory 11 according to the change of the cursor position, and outputs the first V data. -RA
A map image is drawn in M21 such that the center is always at the cursor position, and a cursor mark is drawn in the center of the first V-RAM 21. 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), while the route search unit 15 reads the map data from the CD-ROM 1 from the starting point to the destination to the buffer memory 11 based on the starting point data and the destination point data, by the simulation calculation such as the Dijkstra method or the horizontal search method. For example, an optimum guide route is searched by using the shortest distance as an index, and a series of nodes forming the guide route is set to the start point data (here, node N _s , see FIG. 3) and the end destination data. (Here, the node N _O , see FIG. 3) is stored in the first storage area of the guide route memory 16 in the order of addresses (steps 201 and 20 in FIG. 9).
2). 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 on the left side of FIG.

The route searching unit 15 finds a guide route memory 16 for each intersection in the node sequence forming the guide route.
The intersection identification flag R in the node data of
The intersection data CRDT of the map data and the road link list RD are stored in a predetermined location of the second storage area indicated by the pointer T _j.
The intersection constituent nodes N _j1 , N _j2 , ... Read by referring to the LT and the node list NDLT, and the road width data RD _j1 , RD _j2 ,. The contents of the second storage area are as shown on the right side of FIG. When the search of the guide route is completed, the second distance calculation unit 19 inputs the detection distance h ₁ by the distance sensor 4 and calculates the height h from the ground to the driver's viewpoint (step 203).

After that, 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 around the starting point. The data is read from the CD-ROM 1 to the buffer memory 11, and a map image is drawn on the first V-RAM 21 so that the center is the starting point (steps 204 and 205). Then, the map image drawing unit 13 reads out the nodes included 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, makes them thicker with a different color from other roads. A highlighted guidance route for route guidance is drawn on the 1V-RAM 21 (step 206), and the first V-RAM 21 is drawn.
A vehicle position mark whose vehicle azimuth direction is oriented is drawn in the center of (step 207). The image of the first V-RAM 21 is read by the conversion unit 23, converted into a predetermined video signal, and output to the second display device 6. As a result, the map around the departure place with the vehicle position mark at the departure point in the center is displayed on the screen, and the guide route is displayed in a different color from other roads in bold, so at a glance You will know if you should drive along the road (see Figure 12).

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, the map image is drawn on the first V-RAM 21 so that the vehicle position is at the center (steps 208 and 209). 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.
Draw an emphasized guidance route on 1 (step 210),
A vehicle position mark is drawn in the center of the first V-RAM 21 in the direction indicated by the vehicle direction (step 211). 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, since the flag A indicating that the guidance target intersection / route is specified is 0 (YES in step 301 of FIG. 10), the guidance target / route search in which the vehicle position data and the vehicle direction data are input. The unit 17 refers to the guide route data stored in the guide route memory 16, and refers to the guide route data from the vehicle position on the guide route, for each intersection node that is the closest in front of the vehicle in front of the vehicle, one ingress node, Based on the positional relationship between the intersection node and the exit node after the intersection node, as shown in FIG.
If it is O, the process of determining whether the traveling direction similarly changes for the next intersection on the guide route is repeated, and the traveling direction changing intersection at the position closest to the vehicle position on the guide route. Is determined and the guidance target intersection is specified. Further, the route information is specified by the ingress node before the guidance target intersection on the guide route, the guidance target intersection node, and the exit node after the guidance target intersection. The identified guidance target intersection is the first
The information is output to the distance calculation unit 18, and the specified guidance target intersection and route information are output to the route guidance image drawing unit 20 (step 302). Here, it is assumed that CP ₁ in FIG. 11 is the first guidance target intersection. Then, a flag A indicating that the guidance target intersection and the route information have been specified is set (step 303).

Next, the first distance calculator 18 refers to the vehicle position data and the vehicle azimuth data input from the vehicle position detecting device 3 and the guide route data of the guide route memory 16 corresponding to the guidance target intersection, and refers to the current data. The distance K along the guide route between the vehicle position and the guidance target intersection calculated by the guidance target / route search unit 17 is calculated (step 304). In addition, when the vehicle position comes to a position ahead of the guidance target intersection, K becomes negative. Subsequently, since the flag B indicating that the route guidance image is being displayed is 0 (YES in step 305), the route guidance image drawing unit 20 determines whether the distance between the vehicle position and the guidance target intersection is within 250 (m) (step 306). ), N
If it is O, the route guidance image is not drawn, and the flag B indicating that the route guidance image is being displayed is left at 0 and step 2 in FIG.
Returning to 08, the next vehicle position data and the vehicle direction data are input from the vehicle position detecting device 3, and 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 209 to 211). ).

Since the guidance target intersection has already been specified (NO in step 301 of FIG. 10), the first distance calculation unit 18 calculates the distance K along the guide route between the new vehicle position and the guidance target intersection. (Step 304) Then, since the route guidance image is not yet displayed (Step 305)
YES), the route guidance image drawing unit 20 sets the distance K to 250.
(M) It is determined whether it is less than or equal to (m) (step 306). Where Y
If ES, then set B = 1 (step 30
7) Referring to the vehicle position data and the vehicle direction data input from the vehicle position detecting device 3, the guidance target intersection, and the guidance route data corresponding to the entry node and the exit node, the guidance target intersection CP ₁ of this time is shown in FIG. By the method shown in
Calculate the arrow figure showing the route at the intersection (Step 3)
08).

Then, by the method shown in FIG. 7, 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 plane V is calculated (step 30).
9). Then, the projection image is drawn on the second V-RAM 22 while cutting out a certain range (the window WD corresponding to the area of the route guidance image) on the projection surface V, and the conversion unit 24 converts the projection image into a predetermined video signal, and the first display device. 5 is displayed (step 310). As a result, the arrow figure just superposed on the guidance target intersection CP _{1 in} the landscape is three-dimensionally projected on the windshield FG (FIG. 13).
(See (1)).

After the processing of step 310, the navigation controller 10 returns to step 208 of FIG. 9 to input the next vehicle position data and vehicle direction data from the vehicle position detecting device 3 and move the map according to the change of the vehicle position. , The vehicle position mark and the emphasized guidance route are rewritten (steps 209 to 211). Since the guidance target intersection and the route have already been specified (step 301 in FIG. 10, YE
S), the first 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), and further, because the route guidance image is being displayed (NO in step 305). ), The route guidance image drawing unit 20 determines whether the distance K is negative (step 311).
The method shown in FIG. 6 for the current guidance target intersection CP ₁ with reference to the vehicle position data and the vehicle direction data input from the vehicle position detection device 3, the guidance target intersection, and the guidance route data corresponding to the entry node and the exit node. The arrow figure indicating the route at the intersection is calculated by (step 30
8).

Then, by the method shown in FIG. 7, the arrow figure having a width is placed on a plane below the viewpoint by a certain distance h in the x ',', z'line-of-sight coordinate system and projected at the position in front of the viewpoint k. An image center-projected on the plane V is calculated (step 30).
9). Then, the projection image is drawn on the second V-RAM 22 while cutting out a certain range WD of the projection surface, and the image is read from the second V-RAM 22 by the conversion unit 24, converted into a predetermined video signal, and converted into the first display device 5. Is displayed (step 310). As a result, the driver sees the arrow figure projected on the windshield FG a little closer together with the actual guidance target intersection.

Similarly, as the distance between the vehicle position and the guidance target intersection CP ₁ changes, the three-dimensionally drawn arrow figure sequentially changes so as to approach the guidance target intersection. Go. Initially, when the vehicle position is far from the guidance target intersection, the guidance target intersection and the arrow figure in the landscape appear to be small and far upward (Fig. 13 (1)).
), As the vehicle position approaches the guidance target intersection,
The guidance target intersection and the arrow figure in the landscape gradually move downward and become larger, and appear to approach you (see FIG. 13 (2)). Therefore, the driver looks as if the arrow figure is actually placed on the intersection to be guided, so at any time, at a glance at the arrow figure projected on the windshield FG, the course can be changed at any 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 bends at 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 first distance calculation unit 18 becomes negative, so The guide image drawing unit 20 uses step 31 in FIG.
If YES is determined in 1, the second V-RAM 22 is cleared to temporarily stop the display of the arrow figure (step 312).
Then, the flags A and B are cleared (step 31).
3).

After that, when it comes to step 301 in FIG. 10, the guidance / course specifying unit 17 determines YES and searches for a guidance-requiring intersection where the vehicle should change its traveling direction next to the intersection CP ₁ ( Step 302, C in FIG.
P ₂ ). Then, the first distance calculation unit 18 calculates the distance K between the vehicle position and the guidance target intersection (step 304), 2
When it is within 50 m (YES in step 306),
The route guidance image drawing unit 20 calculates the arrow shape indicating the route at the guidance target intersection CP ₂ (step 308), and projects the three-dimensionally drawn arrow figure on the windshield FG (steps 309 and 310). As the vehicle position changes, the arrow graphic image is redrawn so that the arrow graphic looks closer to the front (step 301,
Repeat 304-310).

When the driver follows the guidance on the screen and passes the _second guidance target intersection CP ₂ , the arrow graphic disappears temporarily, and then the route guidance of the third guidance target intersection is displayed. . Therefore, the destination can be reliably reached only by traveling according to the arrow projected on the landscape.

According to this embodiment, since the arrow figure is superimposed on the position of the actual guidance target intersection in the landscape seen in front of the vehicle to display the route at the guidance target intersection, which intersection is correct at a glance. It is possible to know in which direction the route should be changed, and it is only necessary to look at the scenery without moving the line of sight on the screen of the second display device 6, so that safe driving is possible. Further, since the arrow figure having a width half of 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 scenery.
Further, since the driver's viewpoint is configured to be measured by the measuring means, the position of the actual guidance target intersection seen by the driver and the position of the guidance target intersection on the route guidance image plane can be accurately overlapped.

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 guidance target intersection road, an arrow figure having a constant width, or a narrow arrow figure. It may be performed by an arrow figure having the same width as the road width, a polygonal line figure in which the triangle at the tip is removed from the arrow figure, or by characters such as "left turn" and "right turn". In addition, the guidance target intersection may be the frontmost intersection existing ahead of the vehicle traveling direction on the guide route regardless of whether the traveling direction changes,
Further, even if the distance between the vehicle position and the guidance target intersection is larger than 250 m, a graphic showing the route may be displayed as an image.

Further, when converting the arrow figure of FIG. 6 to the line-of-sight coordinate system of FIG. 7, x ′ = x was set, but the width of the road on which the vehicle is currently traveling is determined from the vehicle position data and the guide route data, When the width W has multiple lanes on each side, x '= x + F However, if the vehicle is traveling in the left turn, it is assumed that the vehicle is traveling in the leftmost lane. F = (W / 2) -width In the case of turning right, it is from the far right. If it is converted into F = 0 as if traveling in the lane, the actual guidance target intersection seen from the windshield can be more accurately overlapped with the arrow figure. Further, the height from the ground to the viewpoint is calculated based on the distance detected by the distance sensor, but a standard value obtained from the standard body type of an adult may be used. In this case, different values are used for men and women. You may do it. Also,
It is also possible to store a relational expression between the height and the viewpoint height and a look-up table, and obtain the corresponding viewpoint height based on the height data input by the driver.

[0042]

As described above, according to the present invention, the optimum guidance route connecting the departure place and the destination is searched and stored with reference to the map data, and the vehicle position is detected while the vehicle is running to detect the current state of the vehicle. From the position and the guidance route information, a predetermined guidance target intersection existing ahead of the vehicle on the guidance route and a route at the guidance target intersection are obtained. Then, from the current position of the vehicle, the position and route of the guidance target intersection, the driver's viewpoint, the position of the image plane of the route guidance image by the display means, the position of the actual guidance target intersection and the image of the route guidance image seen by the driver. The route guidance image at the guidance target intersection is drawn so that the positions of the guidance target intersection on the plane overlap each other, and is displayed on the display means. Since the route guidance image can be seen on top of each other, the driver can grasp at a glance the intersection at which the course should be changed and the route at the intersection while looking at the scenery in front of him, and the course is correct. Since it is not necessary to move the line of sight from the front, safe driving becomes possible.

Further, since the driver's viewpoint is configured to be measured by the measuring means, the actual position of the guidance target intersection seen by the driver and the position of the guidance target intersection on the route guidance image plane are accurately overlapped. You can

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle-mounted navigation device according to an embodiment of 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 operation explanatory diagram of the first display device and the distance sensor.

FIG. 6 is an explanatory diagram of a method of calculating an arrow graphic indicating a route at a guidance target intersection.

FIG. 7 is an explanatory diagram of a method of calculating a three-dimensional center projection image of an arrow figure.

FIG. 8 shows a first operation of the navigation controller.
2 is a flowchart of.

FIG. 9 shows a second operation of the navigation controller.
2 is a flowchart of.

FIG. 10 is a third flowchart showing the operation of the navigation controller.

FIG. 11 is an explanatory diagram showing an outline of roads around a departure place.

FIG. 12 is an explanatory diagram illustrating a screen display example of a second display device.

FIG. 13 is an explanatory diagram of a route guidance image displayed on the windshield.

FIG. 14 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 Distance sensor 5 1st display device 6 2nd display device 10 Navigation controller 15 Route search part 16 Guidance route memory 17 Guidance target / route identification part 19 Second distance calculation part 20 Route guidance image Drawing unit 22 Second V-RAM

Claims (2)

[Claims] 1. A map information storage unit that stores map data, a vehicle position detection unit that detects a vehicle position, and a windshield that reflects light so that a driver can see a route guidance image overlapping with a front scene. Display means, a search means for searching an optimum guide route connecting a departure place and a destination with reference to map data, a guide route storage means for storing guide route information searched by the route search means, and a vehicle. Based on the current position and guidance route information, a predetermined guidance target intersection existing in the forward direction of the vehicle on the guidance route and guidance target / route identification means for determining a route at the guidance target intersection, current position of the vehicle, guidance target intersection From the position and route, the driver's viewpoint, the position of the image plane of the route guidance image by the display means, the position of the actual guidance target intersection seen by the driver and the guidance target intersection on the image plane of the route guidance image An on-vehicle navigation device comprising: a route guidance image drawing means for rendering a route guidance image at a guidance target intersection such that the points are overlapped and displaying the route guidance image on a display means. 2. The vehicle-mounted navigation device according to claim 1, wherein the driver's viewpoint is measured by a measuring means.