JP3458563B2 - Route guidance device for vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular route guide device for displaying a bird's-eye view road map.

[0002]

2. Description of the Related Art A route guidance device for a vehicle is known which guides an occupant by displaying a route to a destination and a current position of the vehicle on a bird's-eye view type road map (for example, Japanese Patent Laid-Open No. 2-244).
188). In this type of vehicle route guidance device, for example, as shown in FIG.
A plan view road map of a trapezoidal area A having a depth of 0 m, a width of about 7 km, and a depth of about 7 km is displayed on a rectangular display screen S of the display as shown in FIG. In the area, the road map is enlarged so that a detailed road map can be seen, and the scale is continuously increased as the distance increases, and a broad road map can be seen.

[0003]

However, in the conventional route guidance device for a vehicle, a bird's-eye view road map centering on the traveling direction of the vehicle is displayed. Therefore, as shown in FIG. Sometimes the route to the destination (represented by a thick line) is only slightly displayed. Originally, in the bird's-eye view road map display, the vicinity of the current location is enlarged to display a detailed road map, and a wide range of road maps is displayed as the distance from the current location increases. There is an advantage that a rough route to the ground can be seen at the same time. However, if only a few routes to the destination are displayed on the display screen, the original advantage of the bird's-eye view described above will not be utilized, and even if the plan view road map is converted into a bird's-eye view and displayed, the plan view road map is displayed as it is. There is a problem that it does not change from when it is done.

An object of the present invention is to provide a route guidance device for a vehicle, which displays as many routes as planned to travel on a display screen.

[0005]

In order to achieve the above object, the invention of claim 1 provides a route guidance device for a vehicle, which displays a current position of a vehicle and a route to a destination on a bird's-eye view road map. When the node on the route to the destination is applied to Ni (i = 1, 2, ...) Ascending from the current position of the vehicle, the distance Li from the current position of the vehicle to the node Ni is
Distance determining means for determining whether or not the distance L from the current position of the vehicle to the farthest position in the bird's-eye view display area on the flat road map, and the direction of the node Ni viewed from the current position of the vehicle and the traveling direction of the vehicle at the current position And azimuth angle θi (i =
1, 2, ..., And, the deflection angle of the difference between the maximum azimuth angle DR on the right side and the maximum azimuth angle DL on the left side of the azimuth angle θi based on the traveling azimuth of the vehicle at the current position | DR- DL |
Maximum deflection angle D that fits within the bird's-eye view display area on the plan view road map based on the traveling direction of the vehicle at the current location
One of the distance determining means and the bearing determining means, the bearing determining means determining whether or not the value exceeds max, and the distance determining means and the bearing determining means sequentially determine from the node Ni close to the current position of the vehicle. If the node at the time of being affirmed is Ni, the line-of-sight azimuth φ = (DR + DL) / 2 based on the maximum azimuth angle DR on the right side and the maximum azimuth angle DL on the left side of the nodes up to the node N (i-1). And a viewpoint determining means for determining a viewpoint based on the line-of-sight azimuth φ. According to another aspect of the vehicle route guidance device of the present invention, the viewpoint and the line of sight in the bird's-eye view are determined based on the direction to the node used for map drawing. According to another aspect of the vehicle route guidance device of the present invention, the viewpoint and the line of sight in the bird's-eye view are determined based on the direction to the node used for the route calculation. A vehicle route guidance device according to a fourth aspect of the present invention is configured to determine a viewpoint and a line of sight in a bird's-eye view based on a direction to a node used for route guidance.

[0006]

FIG. 1 is a block diagram showing the configuration of an embodiment. The controller 1 is composed of a microcomputer and its peripheral parts, and executes a control program to be described later to perform perspective conversion of the plan view road map into a bird's-eye view road map and display the bird's-eye view road map and the optimum route to the vehicle's current location and destination. To do. A direction sensor 2, a distance sensor 3, a GPS receiver 4, a storage device 5, and an input device 6 are connected to the controller 1. The direction sensor 2 detects the traveling direction of the vehicle, and the distance sensor 3 detects the traveling distance of the vehicle. G
The PS receiver 4 receives the GPS signal from the satellite and detects the current position, traveling direction, traveling speed, etc. of the vehicle. In addition, the storage device 5 is a CD that stores road map data in a plan view.
A device such as a ROM, and the input device 6 is a device for setting a destination and the like. The controller 1 is also connected to a display 7 for displaying a road map and character information, a speaker 8 for guiding by voice, and the like.

Here, a method of displaying the bird's-eye view road map will be described. 2 is a diagram for explaining the display principle of a bird's-eye view road map,
3 is an XZ plan view of FIG. 2, and FIG. 4 is a view showing a display area of a bird's-eye view road map. In the bird's-eye view road map, a viewpoint E is set above the height h of a point O which is a distance b behind the current position V of the vehicle, and the direction of the vehicle is looked down from the viewpoint E along the line of sight EF of the angle α. In this case, the display area A of the flat road map developed on the XY plane is perspective-transformed into the virtual screen S set perpendicular to the line of sight EF. An arbitrary point P in the display area A of the plan road map is
A straight line connecting P and the viewpoint E is perspective-transformed to a point P ′ that intersects the virtual screen S. In this embodiment, for example, the height h of the point O located b = 1 km behind the current position V of the vehicle is h = 350 m.
A viewpoint E is set in the sky above, and the direction of the vehicle is looked down from the viewpoint E along the line of sight EF with an angle α = 16 degrees. When the viewpoint E and the line-of-sight EF are set in this way, the display area A has a front width of about 500 as shown in FIG.
m, the width of the back is about 7 km, and the depth is about 7 km, which is a trapezoidal area, and the flat road map in the display area A is perspectively transformed and displayed on the virtual screen S as shown in (b). Further, the display position V ′ on the screen of the vehicle is slightly below the center of the screen as shown in FIG.

Further, in this embodiment, the azimuth (hereinafter, referred to as the line-of-sight azimuth) φ of the line-of-sight EF in the XY plane is determined as follows. Usually, in a vehicle route guidance device, a road is drawn by nodes that indicate intersections, bending points, and mesh intersections, and links that connect the nodes with straight lines. Here, the bending point is the bending point of the road,
A mesh intersection is a regional mesh of roads and road maps (JI
(Defined by S X0410). Now, as shown in FIG. 5, it is assumed that the vehicle travels on the route indicated by the bold line. N1, N2, ... Nodes are present on the route in order from the one closest to the current position V of the vehicle.
At each node Ni (i = 1, 2, ...) On the route, the distance Li from the current position V of the vehicle to the node Ni is calculated, and it is confirmed whether the distance Li satisfies the following condition.

[Mathematical formula-see original document] Li> L, where L is the distance from the current position V of the vehicle to the farthest point in the display area A, as shown in FIG. It is a distance for restricting to the nodes in the area A.

If the distance Li does not satisfy the condition of Expression 1, it is judged that the node Ni is in the display area A, and the current position V
The azimuth θi between the traveling azimuth of the vehicle at the current position V and the azimuth of the node Ni at the current position V is calculated. Further, of the azimuth angles θi of each node Ni with reference to the traveling azimuth of the vehicle at the current position V, the maximum right and left azimuth angles are recorded as the right-side deflection angle DR and the left-side deflection angle DL, respectively. Then, it is confirmed whether the deflection angles DR and DL satisfy the following conditions.

## EQU00002 ## | DR-DL |> Dmax Here, Dmax is the maximum deflection angle on the left and right with respect to the traveling direction of the current position V as shown in FIG. 6, and the calculation target node of the line-of-sight direction φ is displayed. It is the maximum deflection angle for restricting to the nodes in the area A. If the distance Li satisfies the condition of Expression 1 or the deflection angles DR and DL satisfy the condition of Expression 2, it is determined that the node Ni is out of the display area A, and the deflection of the node N (i-1) The line-of-sight azimuth φ is calculated by the following equation based on the angles DR and DL.

## EQU3 ## φ = (DR + DL) / 2 Further, the coordinates (VX, VY, VZ) of the viewpoint E are calculated by the following equation.

[Expression 4] VX = (x coordinate of current position V) −M * cos φ, VY = (y coordinate of current position V) −M * sin φ, VZ = h

In the example shown in FIG. 5, first, the distance L1 to the node N1 closest to the current position V is calculated, and it is confirmed whether or not the distance L1 satisfies the condition of Expression 1. When the distance L1 does not satisfy the condition of Expression 1, the azimuth angle θ1 with respect to the node N1 is calculated. Since the azimuth of the node N1 is on the right side of the traveling direction of the vehicle, the sway angle DR on the right side indicates the node N
The azimuth angle θ1 of 1 is recorded, and the deflection angle DL on the left side is recorded as 0. Then, it is confirmed whether or not the deflection angles DR and DL satisfy the condition of Expression 2. When the distance L1 satisfies the condition of Expression 1, or when the deflection angles DR and DL satisfy the condition of Expression 2, the coordinates of the line-of-sight azimuth φ and the viewpoint E are calculated by Expressions 3 and 4. Distance L1 or deflection angles DR, DL
If none of the above satisfy the above conditions, the above operation is performed on the next node N2. Here, when the distance Li from the current position V to the node Ni satisfies the condition of Expression 1 and the calculation of the line-of-sight azimuth φ is completed, the case is a relatively straight route as shown in FIG. The route is displayed up to the top of. On the contrary, when the deflection angles DR and DL satisfy the condition of Expression 2 and the calculation of the line-of-sight azimuth φ is completed, the route is a meandering route as shown in FIG. 8, and the route is from the left end or the right end of the display screen S. Comes off.

By the way, as described above, the nodes represent intersections, bends and mesh intersections on the road. However, by selecting the node to be calculated when calculating the line-of-sight azimuth φ, the line-of-sight azimuth φ according to the purpose is selected. Obtainable. The nodes are classified into three types: a map drawing node, a route calculation node, and a route guidance node. The map drawing node is a node necessary for drawing a road map, and is the finest node including all nodes of intersections, bending points, and mesh intersections, as indicated by black circles in FIG. The route calculation node is, for example, a node used to calculate an optimum route to a destination, and is a node of intersections and mesh intersections as shown by small circles in FIG. Further, the route guidance node is, for example, a node used for guidance on the optimum route to the destination, and as shown by the great circle in FIG. Except for a special node (for example, a node that divides into two nodes such as a six-way road), it is an intersection node that requires the occupant's branch judgment. The map drawing node can obtain the line-of-sight azimuth φ so that the route can be accurately entered in the display screen, but has the drawback of requiring a long calculation time. On the other hand, in the route guidance node, the calculation time is short, but the probability that the route deviates from the screen is high because accurate information of the route is lost.

FIG. 10 is a flowchart showing the map drawing process of the controller 1, and FIG. 11 is a line-of-sight direction φ and a viewpoint E.
3 is a flowchart showing the calculation process of FIG. The operation of one embodiment will be described with reference to these flowcharts. When the main switch of the input device 6 is turned on, the controller 1 starts this map drawing process. In step 1, the destination set by the input device 6 is read, and in the following step 2, the azimuth sensor 2, the distance sensor 3 and the GPS receiver 4 detect the current position and the traveling azimuth of the vehicle. In step 3, the optimum route from the current position to the destination is calculated by referring to the plan view road map data in the storage device 5. In step 4, the subroutine shown in FIG. 11 is executed to calculate the line-of-sight azimuth φ and the viewpoint E. This calculation process will be described later. In step 5, the display area A on the plan view road map is calculated based on the viewpoint E, the line of sight EF, and the line of sight azimuth φ, and in step 6, the plan view road map data including the display area A is read from the storage device 5. In step 7, the plan view road map data is converted into bird's-eye view data, and in step 8, the bird's-eye view road map is drawn on the display 7. At this time, the current position mark is displayed at the current position of the vehicle detected by GPS navigation or self-contained navigation, and the optimum route is displayed. In step 9, it is confirmed whether or not the vehicle has moved or rotated, and if there is movement or rotation of the vehicle, the process returns to step 4 and the above processing is repeated.

Next, the calculation processing of the line-of-sight azimuth φ and the viewpoint E will be described with reference to FIG. In step 11, the traveling directions of the vehicle at the current position are set to the deflection angles DR and DL, and in step 12, the parameter i indicating the node number is set to 1 and initialized. In step 13, the coordinates of the node Ni are read, and in step 14, the distance Li from the current position V to the node Ni is calculated. Then, in step 15, the distance L
Whether i satisfies the condition of Expression 1, that is, the current position V
Check whether or not the node Ni located at the distance Li is within the display area A. If the distance Li exceeds the predetermined distance L and deviates from the display area A, proceed to step 23. If within the display area A, proceed to step 23. Proceed to 16. Distance L to node Ni
When i is equal to or less than the predetermined distance L, it is determined that the node Ni is in the display area A, and in step 16, the current position V is changed to the node N.
The direction to i is calculated, and the azimuth angle θi between the traveling direction at the current position V and the direction of the node Ni is calculated. Next, in step 17, it is confirmed whether the azimuth angle θi is larger than the left deflection angle DL, and if it is larger than the deflection angle DL, the azimuth angle θi of the node Ni is recorded in the deflection angle DL. Further, in step 19, it is confirmed whether or not the azimuth θi is smaller than the right deflection angle DR, and if it is smaller than the deflection angle DR, the azimuth θi of the node Ni is recorded in the deflection angle DR. In step 21, it is confirmed whether or not the deflection angles DR and DL satisfy the condition of expression 2, that is, whether the node Ni is in the display area A. If the condition of expression 2 is satisfied, the process proceeds to step 23. If not, the process proceeds to step 22. Step two
At 2, since the node Ni is in the display area A, the parameter i is incremented and the process returns to step 13 to perform the above-described processing on the next node N (i + 1). On the other hand, when the deflection angles DR and DL satisfy the condition of Expression 2, it is determined that the node Ni has deviated from the left end or the right end of the display area A, and in Step 23, the line-of-sight azimuth φ is calculated by Expression 3, and in the subsequent Step 24. The coordinates of the viewpoint E (V
X, VY, VZ) is calculated.

[0014]

As described above, according to the present invention, more routes to be traveled are displayed on the display screen, and the advantage of the bird's-eye view display is utilized to obtain a detailed road map around the vehicle and a rough route to the destination. The route and the passenger can be provided at the same time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment.

FIG. 2 is a diagram for explaining the display principle of a bird's-eye view road map.

FIG. 3 is an XZ plan view of FIG.

FIG. 4 is a diagram showing a display area of a bird's-eye view road map.

FIG. 5 is a diagram illustrating a method of calculating a line-of-sight azimuth φ.

FIG. 6 is a diagram illustrating a method of selecting a node used for calculating a line-of-sight azimuth φ.

FIG. 7 is a diagram showing a relationship between a path close to a straight line and a display area A.

FIG. 8 is a diagram showing a relationship between a winding path and a display area A.

FIG. 9 is a diagram illustrating types of nodes.

FIG. 10 is a flowchart showing map drawing processing.

FIG. 11 is a flowchart showing a calculation process of a line-of-sight azimuth φ and a viewpoint E.

FIG. 12 is a diagram illustrating a problem of a conventional vehicle route guidance device.

[Explanation of symbols]

1 controller 2 direction sensor 3 distance sensor 4 GPS receiver 5 storage devices 6 Input device 7 display 8 speakers

Continuation of front page (56) Reference JP-A-7-190793 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01C 21/00 G08G 1/0969 G09B 29/00

Claims (4)

(57) [Claims] 1. A route guidance device for a vehicle, which displays a current location of a vehicle and a route to a destination on a bird's-eye view road map, in which nodes on the route to the destination are arranged in order from the current location of the vehicle.
Where Ni (i = 1, 2, ...) is the current location of the vehicle
The distance Li from the node to the node Ni is
Distance to the farthest point in the bird's-eye view display area on the road map
Distance determining means for determining whether or not L is exceeded, and the direction of the node Ni viewed from the current position of the vehicle and the current position.
Azimuth θi (i = 1, 2, ...
・) Is calculated and the traveling direction of the vehicle at the current location is used as a reference
Maximum azimuth angle DR on the right side of the azimuth angle θi and maximum on the left side
The deflection angle | DR-DL |, which is the difference from the azimuth angle DL, is the current position.
Plan map with reference to the traveling direction of the vehicle
Exceeding the maximum deflection angle Dmax that fits in the upper bird's-eye view display area
Direction determining means for determining whether or not the distance is determined, and the distance determining procedure is performed in order from the node Ni closest to the current position of the vehicle.
The distance is determined by the step and the direction determining means.
Either one of the means and the direction determining means is affirmed
If node Ni is Ni, up to node N (i-1)
Maximum azimuth DR on the right side and maximum azimuth DL on the left side of the node
Based on and, the line of sight φ = (DR + DL) / 2
A vehicle route guidance device comprising: a line calculation means; and a viewpoint determination means that determines a viewpoint based on a line-of-sight direction φ . 2. The vehicle route guiding apparatus according to claim 1, wherein the bird's-eye view is based on a direction to a node used for drawing a map.
A route guidance device for a vehicle, which determines a viewpoint and a line of sight in a vehicle. 3. The vehicle route guiding apparatus according to claim 1 , wherein the bird's-eye view is based on a direction to a node used for route calculation.
A route guidance device for a vehicle, which determines a viewpoint and a line of sight in a vehicle. 4. The vehicle route guidance device according to claim 1 , wherein the bird's-eye view is based on a direction to a node used for route guidance.
A route guidance device for a vehicle, which determines a viewpoint and a line of sight in a vehicle.