JP3208861B2 - Electronic map device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic map device having a road traffic information service function.

[0002]

2. Description of the Related Art In recent years, miniaturization of electronic equipment, CD-ROM
It is possible to reduce the size of large-capacity data by using it. With these technologies, map data is converted to CD-ROM, portable map data is displayed on a display, and in combination with a positioning function, a self-position is displayed on a map,
An electronic map device for searching for destinations was born.

A conventional electronic map device will be described below. FIG. 5 is a configuration diagram of a conventional electronic map device. In the figure, reference numeral 1 denotes a CPU for controlling the entire system, and a system RO.
M, a central unit of an electronic map system including a system RAM and an image memory, 2 is an image display device including a display device such as a CRT and a display driver for driving the same, 3 is a CD-ROM reader and stores read data. A CD-ROM device including a buffer memory for reading a CD-ROM, a keyboard 4 for inputting a processing command, and a positioning device 5 for measuring a current position.

The electronic map device reads map data from a CD-ROM in accordance with a user's instruction, develops the map data in an image memory, and displays it on the screen of the image display device 2.
Then, the current position obtained from the positioning device 5 is displayed over the screen. Positioning is generally performed with high accuracy using radio waves from satellites.

[0005] In addition, services relating to static events such as building names and uses can be provided to users by using service information recorded on a CD-ROM. The provided information is only for information within the display map range. This information is map data and service data.

[0006]

However, such a conventional electronic map apparatus has the following problems. On the screen, the current position is indicated by a bright point on the map with the place name written, so the user can determine where to go from the current position and the name of the passing point when going to other points You must follow the map by eye. In addition, since the map range that can be displayed is limited depending on the screen resolution of the electronic map device, an operation of switching the screen may be required.

An object of the present invention is to solve the above-mentioned problems, and to provide an electronic map apparatus for presenting a user with a list of points (towns and intersections) that can be reached from a certain point (town or intersection). And

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a display means and map information for storing map information.
Storage means, input means for inputting processing instructions, and current position
Positioning means for measuring the distance from the map information storage means
Consider each city and intersection on the map as one node
None, connect each node to other nodes connected at 1-node intervals
Memorize as a connection point list and refer to this connection point list
And depart from one point without setting a destination
Reachable by arranging the names of points passing from in a tree shape
A power source configured to display a point list on the display means.
A child map device was used.

[0009]

According to the present invention, the present invention makes it possible to check which location can be reached starting from a certain point without following the map up, down, left and right. Can be confirmed from the route.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of an electronic map device according to one embodiment of the present invention will be described below with reference to the drawings. The configuration of the electronic map device in the present embodiment is the same as that of the conventional example shown in FIG.

FIG. 1 is a simplified view of a general display screen of an electronic map device. Roads with a width of 3.3m or more,
The names of the streets and intersections where the road intersects and the streets where the road passes are displayed. City names are indicated by alphabets, and road junctions (intersection names) are indicated by pseudonyms. On this screen, the current position obtained by the positioning device can be displayed as a bright spot.

The case where the current position of the user is A will be described. 1) When you want to know where you can go from your current position. If you follow the road on the screen up, down, left, right, and up, you can search for where you can go. Therefore, the usability of the user is improved. Specifically, as shown in FIG. 2, a connection point list indicating where each point connects is created, and the CD-R
It is linked to the map data and recorded on the OM. In other words, the connecting cities and intersections are recorded in each city and each intersection. Referring to this connection list, a tree-like “reachable point list starting from A” as shown in FIG. 3 is displayed on the screen. The user can select a destination with reference to the reachable point list. At the time of creating this list, the route that has returned to the point that has already passed is not displayed. Also, care should be taken to distinguish the dead end by changing the character color and the like. 2) When Condition is Applied at the Time of List Creation When the reachable point list is displayed without any conditions as in 1), the reachable point list becomes enormous and it is difficult to display it on one screen. Therefore, some conditions are given to the reachable point. An example of this conditioning is shown below.

(A) The passing points are limited to points on the same screen. (B) As shown in FIG. 4, cities and intersections linked by roads are classified to classify the conditions for list display. In other words, display / non-display points are divided.

(C) A departure point and a destination are set, and the reachable (passable) points only during this time are displayed. A list can be created by superimposing these conditions. For example, by superimposing (b) and (c), displaying the route from the starting point to the destination, and confirming whether or not the wrong route has been taken in a location where the positioning function is insufficient such as a mountain area when moving. It can be information. However, only one node is displayed on roads other than the route in order to make it understood that the road is a branch at a branch point. Since this is given in the connection point list of FIG. 2, the search display can be performed at high speed. FIG.
Fig. 7 shows the route candidates displayed under the conditions (b) and (c). In other words, the departure place (A) and the destination (E) are set, and an easy-to-understand route candidate is displayed using the reference data of FIG. At each branch point, only the road other than the route is displayed for one node in order to understand that it is a branch point.

FIG. 7 is a flowchart showing the difference between the case of performing the route display and the case of not performing the condition (c). The difference is whether or not the process of searching for a route that can reach the destination in (5) in the figure is performed. Whether or not to perform this processing is determined by determining whether or not the destination setting in (4) in the figure has been performed. That is, when a destination is set, only routes that can reach the destination are displayed.

FIG. 8 is a flowchart of a process of creating a reachable list from the current location, which corresponds to the process (3) of FIG. Route search processing from a certain branch point (see FIG. 8)
(5) of (a) and (6) of (b) of FIG. 8 are performed by recursively calling the subroutine "retrieval of child level" of (b) of FIG. When performing recursive processing, the level of the variable area is changed each time a subroutine is called in order to avoid destruction of values due to overlapping of variables of the same name.

By processing as shown in the flowchart of FIG. 9, it is possible to perform processing for searching only the destination reachable route corresponding to (5) of FIG. That is, from the reachable point list created by the algorithm shown in FIG. 8, a route that can reach the destination is selected, stored, and displayed on the screen.

It is also possible to display the sights and the like near the current position from the service information stored on the CD-ROM, and to designate one of them as the destination to perform route display. Will be more convenient. 3) When actually moving When moving from the point A to the point E, it is possible to display only the route candidates after the current position being moved by notifying the central device that the vehicle has passed the branch point. The fact that the vehicle has passed the branch point can be known from information from the positioning device. However, when the positioning function does not work well or when the user wants to display a route beyond a certain point other than the current position, the user specifies the branch point on the screen using the keyboard and the central device You can inform the department.

As described above, according to the present embodiment, a central device including a CPU for controlling the entire system, a system ROM, a system RAM, and an image memory, and an image display including a display device such as a CRT and a display driver for driving the display device. A device, a CD-ROM device, a keyboard for inputting processing instructions, and a positioning device for measuring the current position are provided, and each of the cities and intersections on the map is regarded as one node, and each node is connected with a distance of one node. The other nodes are stored as a connection point list, and by referring to the connection point list, a reachable point list is displayed in which the names of points passing through after departure from a certain point are arranged in a tree shape, and reachable points are displayed. Searching for a destination including the destination from the point list, it is possible to display only the route to the destination.

[0020]

As is clear from the above embodiments, according to the present invention, by presenting the reachable list, it is possible to find out what kind of place can be reached starting from a certain point without following the map up, down, left and right. be able to. Also,
By presenting several routes from a certain point to a certain point, it is possible to provide an electronic map device that can help the user in selecting a route and confirming a traveling road.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a case where a map of a certain area is displayed on an image display device in one embodiment of the electronic map device of the present invention.

FIG. 2 is an explanatory diagram showing an example of a database used when creating a reachable point list according to the embodiment;

FIG. 3 is an explanatory diagram showing an example of a case where a list of points reachable from a certain point is displayed in a tree shape in the embodiment;

FIG. 4 is an explanatory diagram showing an example of a database used to condition creation of a reachable point list according to the embodiment;

FIG. 5 is a block diagram showing a configuration of the present invention and a conventional electronic map device.

FIG. 6 is an explanatory diagram showing an example in which a route candidate is displayed on an image display device in the embodiment.

FIG. 7 is a flowchart of a processing algorithm for displaying a route candidate to a user on a screen in the embodiment;

FIG. 8 is a flowchart of a processing algorithm for creating a reachable point list in the embodiment.

FIG. 9 is a flowchart of a process of searching for a route that can reach a destination in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central device part 2 Image display device 3 CD-ROM device 4 Keyboard 5 Positioning device

Continuation of front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 21/00 G06F 17/30 G06T 1/00 G08G 1/0969 G09B 29/10

Claims (2)

(57) [Claims] 1. A display device comprising: a display unit; a map information storage unit for storing map information; an input unit for inputting a processing command; and a positioning unit for measuring a current position. Regarding each city and intersection as one node, other nodes connected to each node at one-node intervals are stored as a connection point list, and referring to this connection point list, depart from one point without setting a destination An electronic map apparatus configured to display names of reachable points on the display unit by arranging the names of points to be passed afterwards in a tree shape. 2. A map comprising : a display means; a map information storage means for storing map information; an input means for inputting a processing command; and a positioning means for measuring a current position. Regarding each city and intersection as one node, other nodes connected to each node at one-node intervals are stored as a connection point list, and referring to this connection point list, one point as a starting point is directly or directly connected to this point. An electronic map device configured to display a reachable point list in which names of indirectly connected points are arranged in a tree shape on the display means.