JP2782134B2 - Vehicle travel guidance device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle travel guide system for searching for a route from a starting point set on a road map displayed on a screen to a destination and guiding the vehicle. .

[0002]

2. Description of the Related Art Recently, a starting point and a destination are arbitrarily set on a road map displayed on a screen, and an optimum route from the set starting point to the destination is set based on digital map data. A vehicle travel guide device has been developed which searches for a vehicle and guides the vehicle along the searched route (for example, Japanese Patent Laid-Open No. 62-133).
No. 600 or JP-A-1-173297).

As digital map data, the actual road shape as shown in FIG. 3 is approximated by broken lines as shown in FIG. It consists of data on the connection status between the two.

[0004] As can be seen from FIG. 4, a curved portion of a road is finely digitized by a short line segment in accordance with the curvature.

Conventionally, in order to perform a route search based on digital map data, in order to perform a shortest route search from a starting point to a destination according to a known algorithm such as Dijkstra method, It will follow connected nodes on the digital map one after another so that the required distance is the shortest,
When searching for a route over a wide area, it is necessary to follow a large number of nodes, and in sections where there are many curved parts of the road, digitization has been made fine so that many nodes have to be followed. The processing for tracking is complicated and the processing time is long.

[0006]

The problem to be solved is that when a route search is performed based on digital map data, a large number of nodes must be followed when a route search is performed over a wide area. In sections where there are many curves, the digitization is so fine that many nodes must be traced, and the processing for node tracking becomes complicated and the processing time becomes longer. .

[0007]

The present invention considers nodes between intersections when searching for a route from a starting point set on a road map to a destination based on digital map data. Focusing on the fact that the route search can be performed by following only the nodes at the intersections on the route one after another, the digital map data is used to effectively reduce the processing for node tracking. A route that connects only the nodes that are the minimum necessary for the route search, such as the nodes at each road endpoint and each intersection on the road map, and that connects the nodes that are connected to each road endpoint and each intersection. the search map data in terms of the newly created, so that to perform a route search in accordance with the created route search <br/> map data.

[0008]

FIG. 1 shows an example of the configuration of a vehicle traveling guide device according to the present invention.
And a direction sensor 2 that outputs a signal proportional to the amount of direction change accompanying the traveling of the vehicle, for example, detects a change in the angular velocity in the yaw direction, and counts the number of pulse signals from the distance sensor 1 to measure the traveling distance of the vehicle. At the same time, the current position on the XY coordinate for each constant traveling distance of the vehicle is obtained by successively calculating the change in the traveling direction according to the output signal of the direction sensor 2, and A signal processing device 3 comprising a microcomputer for performing control and data of a current position of a position on the X-Y coordinates, which is constantly changing, obtained by the signal processing device 3 are sequentially stored, and finite continuous position information of the vehicle is stored. A travel locus storage device 4 for storing and holding the same, and a map information storage medium in which road map information based on digital map data is stored in advance. 5, a storage medium reproducing device 6 for selectively reading road map information of a necessary area from the storage medium 5, and a predetermined road map based on the read road map information. A display device 7 for updating and displaying the current position of the vehicle on the road map projected on the display along with the traveling locus and the traveling direction of the vehicle at the current position as necessary as the vehicle travels; and a signal processing device. 3, an operation command is given to the display device 7, a selection of a map to be displayed on the display device 7 and a setting of a starting point and a destination of the vehicle on the displayed map are performed. To change the direction of the displayed map and running trajectory,
An operation device 8 is provided which can appropriately change the display mode, such as shifting the display position, partially enlarging the map and the traveling locus, and selecting the display scale.

In the above-mentioned configuration, the road map selectively read out is displayed on the screen of the display device 7, and the signal processing is performed in accordance with the traveling of the vehicle from the starting point set on the map. The current position on the XY coordinates is calculated by the device 3 in accordance with a preset scale of the map, and the calculation result is sequentially transmitted to the travel locus storage device 4 to update the stored content. At the same time, the stored contents are read out and sent to the display device 7.

As a result, for example, the display device 7 shown in FIG.
As shown in the figure, on the map displayed on the screen, a display mark M1 indicating the current position of the vehicle, a display mark M2 indicating the traveling direction of the vehicle at the current position, and a traveling locus from the starting point S to the current position. The display mark M3 is simulated and displayed following the running state of the vehicle.

The present invention relates to such a vehicle travel guide device, and in a signal processing device 3, from a starting point set on a road map displayed on a screen to a destination, based on digital map data. Search for the route and determine the optimal route taking into account road information such as the required distance and one-way traffic. For example, the optimal route on the road map displayed on the screen is indicated by a special color, The vehicle can be guided to travel so that the current position of the vehicle is updated and displayed above.

At this time, in the present invention, as shown in FIG. 5, when searching for a route from the starting point S set on the road map to the destination O, the intersections I1, I2 and I
, I2, I3,..., I on the route without any consideration of the node N between
Focusing on the fact that the route search can be performed by following only the nodes corresponding to n sequentially, the signal processing device 3 uses the digital map data read from the map information storage medium 5 to display the route map on the road map. Only the data related to the nodes at each road end and each intersection is extracted, and the nodes in the connection relationship between each road end and each intersection are extracted.
After newly creating route search map data connecting between the routes, a route search is performed according to the created route search map data.

FIG. 6 shows a digital map according to the digital map data read from the map information storage medium 5, and FIG.
9 shows digital maps according to route map data newly created from the digital map data.

The connection relationship between each road end point and each intersection in the newly created digital map has not changed at all from the original digital map, and therefore, on the route from the starting point to the destination. By successively following the nodes at the intersections in, the route search can be performed accurately and quickly with a small amount of map data.

Various known methods are widely applied to the basic algorithm of route search and the determination of the optimum route itself.

[0016]

As described above, in the vehicle travel guide device according to the present invention , the actual road map is displayed on the screen.
Only the data related to the nodes of each road end point and each intersection on the road map is extracted from the digital map data for connection, and there is a connection relationship between each road end point and each intersection.
After having created a new route search map data connecting between nodes, with the route search map data only the data amount is effectively reduced without connection of the each road end points and each intersection is changed in any way, By following the nodes at the intersection on the route from the starting point to the destination one after another, the route search can be performed accurately and quickly while effectively reducing processing for node tracking. Can be . Also, the searched route is used for the original display.
Is displayed on the screen according to the digital data of
Display on a road map that matches the actual situation, and from the starting point to the destination
There is an advantage that it is possible to optimally perform the route guidance up to .

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle travel guide device according to the present invention.

FIG. 2 is a diagram showing an example of display contents in the embodiment.

FIG. 3 is a diagram illustrating an example of an actual road shape.

FIG. 4 is a diagram showing a digital map of the road in FIG. 3;

FIG. 5 is a diagram showing an example of a route from a starting point set on a road map to a destination.

FIG. 6 is a diagram showing an example of a digital map according to digital map data read from a map information storage medium.

7 is a diagram showing a digital map according to route map data newly created corresponding to the digital map of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Distance sensor 2 Direction sensor 3 Signal processing device 4 Travel locus storage device 5 Map information storage medium 6 Storage medium reproduction device 7 Display device 8 Operation device

Claims (1)

(57) [Claims] 1. A departure set on a road map projected on a screen on the basis of digital map data comprising data relating to nodes of end points and connection points of each line segment when an actual road shape is approximated by a line segment. In a vehicle travel guidance device that searches for a route from a point to a destination and guides the vehicle, only data relating to each road end point and each intersection node on the road map is extracted from the digital map data. Means for creating route search map data connecting nodes having a connection relationship between each road end point and each intersection, and means for performing a route search in accordance with the created route search map data. A vehicle travel guide device characterized in that: