JPS6298497A - Vehicle navigation apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle navigation device that displays the current location of a vehicle and a map on the screen of a display device and guides the vehicle to a destination.

[Summary of the invention]

The present invention relates to a vehicle navigation device that displays the current position of a vehicle and a map on the screen of a display device to guide the vehicle to a predetermined destination. When the distance to a fixed point is calculated and the distance is less than a predetermined value.

Reading information regarding the predetermined point from the first storage means.

By storing the information in the second storage means, it is possible to always provide information regarding a predetermined point to the driver with sufficient margin.

[Conventional technology]

Vehicle navigation devices that guide the vehicle to a destination by displaying the current location of a vehicle such as a car on the screen of a display device by superimposing it on map information previously stored in a storage means have been actively researched and developed. Some of them have already been commercialized.

Such a vehicle navigation device detects the current position of the vehicle using various sensors, displays the position on a map,
The current location or map is moved as the vehicle travels. In areas with many roads, such as urban areas, an enlarged map of the vicinity is displayed along with the current location.

[Problem that the invention seeks to solve]

However, since conventional vehicle navigation devices only display the current position of the vehicle on such an enlarged map, they are of little use in areas where intersections are located close to each other in a complicated manner.

[Means for solving problems]

FIG. 1 is a block diagram of a vehicle navigation system according to the present invention. In the figure, reference numeral 1 denotes an image file serving as a storage means for storing map information, and can be constructed from, for example, a CD-ROM, a video tape, or the like. The image file 1 stores normal map information and information regarding major intersections included in the map information. Information regarding intersections is stored as information for each approach road corresponding to the approach road to the intersection. 2 is image file 1
This is a reading device that reads information stored in the computer, decodes it, and outputs the decoded information to an arithmetic unit 3 such as a microcomputer. Reference numeral 4 denotes an arithmetic memory including a RAM, a ROM, etc., which stores programs for controlling the operation of the arithmetic unit and other necessary information.

Reference numeral 5 denotes sensors that detect data necessary to recognize the current position of the vehicle, such as the traveling speed, distance, direction, etc., and the detection signal is supplied to the position recognition device 6 so that the current position can be recognized. It has become. Information regarding the recognized current position is output to the arithmetic device 3. Reference numeral 7 denotes an operation switch that is operated when instructing or inputting a predetermined operation to the arithmetic device 3. 8 is a main image memory, 9 is a sub-image memory,
The former constitutes a storage means for storing map information among the information read from the image file 1-, and the latter constitutes a storage means for storing information regarding intersections. Information stored in the main image memory 8 or the sub-image memory 9 is selectively selected by a switch 10 and displayed on a display device 1 such as a CRT or LCD.

[Effect]

The effect will now be explained. Navigation by this device is executed by the arithmetic device 3 according to a flowchart as shown in FIG. 5, for example.

That is, when the vehicle is traveling toward a predetermined destination, the sensors 5 detect data such as the vehicle's traveling speed, distance, direction, etc. necessary for recognizing the current position using a known method. This detected data is supplied to the position recognition device 6, and the current position is recognized. The arithmetic device 3 reads a map including the current position recognized by the position recognition device 6 from the image file 1 via the reading device 2, and stores it in the main image memory 8 together with the current position. At this time, the arithmetic unit 3 switches the switch 10 to the main image memory 8 side, so that the map including the current position is displayed on the display device i as well as the current position.
'll is displayed.

In such a state, the calculation device 3 calculates the distance between the current position and the main intersections whose information is stored among the intersections on the map displayed on the screen. For example, as shown in Figure 2, when intersections A to F are displayed on the screen as intersections whose information is stored, the distance between these intersections and the current position on the way from intersection B to intersection E is calculated.潴is calculated. Such calculations are performed based on the orthogonal coordinates (X, Y coordinates) of each point, as shown in FIG.

For example, if the distance between intersections A and B is 1, the coordinates of intersection A are (
X, a, Ya ), the coordinates of intersection B are (, xb,
yb), then 1= ((Xa - Xb)"+ (Ya - Yb)
2) Becomes M.

Next, within a predetermined distance of 12 from the current position (
It is determined whether or not there is an intersection within the circle indicated by the number ■ in FIG. If there is an intersection within the distance 12, information regarding that intersection is being displayed on the display device 11, so the sequence returns to the start. When there is no intersection within distance 17, arithmetic device 3 switches switch 10 to main image memory 8 side. Therefore, the map stored in the main image memory 8 remains displayed on the display device 11.

Next, the arithmetic device 3 operates within a predetermined distance 1, (
It is determined whether there is an intersection (within the circle indicated by the number I in FIG. 2). If there is no intersection within the predetermined distance 11, the sequence returns to the start. If there is an intersection within a predetermined distance 11, the intersection with the same traveling direction and the shortest distance is searched and selected.

For example, as shown in Figure 3, the intersection is
When an intersection has two approaches, there are four pieces of information about the intersection, corresponding to the approaches. That is, since approach road A is heading west-northwest (WNW), an image of the intersection seen from approach road A is stored together with the symbol WNW. Similarly, an image of the intersection seen from the approach road entrance with the symbol SSW corresponding to the approach road entrance heading south-southwest (SSW) and an image of the intersection seen from the approach road C with the symbol ESE corresponding to the approach road C heading east-southeast (158E). The image of the intersection is
Furthermore, corresponding to the approach road 2 heading north-northeast (NNE), images of the intersection seen from the approach road 2 are stored together with the symbol NNE. For example, when the direction in which the vehicle is currently traveling is west-northwest (WNW), information on an intersection from approach road A having the symbol WNW is searched and selected from image file 1.

Furthermore, it is determined whether the selected information is already stored in the sub-image memory 9. If the information is not yet stored, the information is read from the image file 1 and stored in the sub-image memory 9. In other words, in Fig. 2, when the intersection E that the vehicle approaches as it travels enters the circle indicated by the number ■, among the information about the intersection E, the information viewed from the direction in which the vehicle is traveling is stored in the sub-image memory. 9 is stored in advance.

When the information is stored in the sub-image memory 9, or has already been stored, it is then determined whether there is an intersection within a distance of 1□. If there is no intersection within a distance of 1□, the sequence returns to the start. When there is an intersection within a distance of 1□, the switch 10 is switched to the sub-image memory 9 side, and information about that intersection is displayed on the display device 11.

That is, when the intersection E enters the circle indicated by the number ■ in FIG. 2, an image of the intersection E viewed from the direction of the intersection B will be displayed.

The distances 1□ and 1□ can be arbitrarily set by the user using the operation switch 7.

=7- Note that the information regarding the intersection is not limited to image information, and may be audio information or both. Furthermore, information on predetermined points other than intersections can also be displayed.

〔effect〕

As described above, the present invention provides a vehicle navigation system that displays the current position of the vehicle and a map on the screen of the display device to guide the vehicle to a predetermined destination. The distance to the predetermined point is calculated, and when the distance becomes less than the predetermined value, the information regarding the predetermined point is read from the first storage means and stored in the second storage means. can always obtain information about a given point with plenty of time. Therefore, even if it takes some time to read out the information regarding the map or a predetermined point from the storage means, sufficient time can be secured for dealing with the problem.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the vehicle navigation system of the present invention, FIGS. 2, 3, and 4 are schematic explanatory diagrams of its map-8=information, and FIG. 5 is its flowchart. 1... Image file 2... Reading device 3...
Arithmetic device 4...Arithmetic memory 5...Sensors
6...Position recognition device 7...Operation switch 8...
・Main image memory 9...Sub image memory 10...Switch 11...Display device or higher

Claims (1)

[Claims] Displaying the current position of the vehicle and a map on the screen of a display device,
In a vehicle navigation device that guides the vehicle to a predetermined destination, the distance between the current position of the vehicle and a predetermined point displayed on the screen of the display device is calculated, and the distance is determined to be less than or equal to a predetermined value. A vehicle navigation device characterized in that when the predetermined point is reached, information regarding the predetermined point is read from the first storage means and stored in the second storage means.