JPS63187931A - Path information transmitting method - Google Patents

Abstract

PURPOSE:To curtail transmission information quantity by preparing that which consists of information of a node and information of a link for linking two points of its node, as a map data base, and transmitting the path information by only node number information. CONSTITUTION:First of all, an ID code, namely, an identification signal of each moving body of an automobile, etc., to be guided is sent, and subsequently, information for showing that the transmission contents are a path guidance is sent as a mode header. Next, X and Y coordinates in the area of a destination, for instance, the destination B are sent, and information of numbers of nodes 2, 3, 4 and 5 in order of the path is sent as path information. In case transmitting information sent in such a way has been received, for instance, the path of a part of links 1, 2, 4 and 6 in the area displayed on a display is displayed, for instance, by a flickering display.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for transmitting route information in a mobile position information communication system using, for example, a geostationary satellite.

[Summary of the invention]

This invention transmits information indicating the current location of the moving object, that is, the current route, and guidance route information when guiding the moving object between moving objects or between a moving object and a fixed center station. In this case, a map database containing branch point (hereinafter referred to as node) information and link information is prepared, and only node information in route order is transmitted as transmission information, and the amount of information to be transmitted is In terms of the amount of information, it is also possible to transmit separate information other than route information.

[Conventional technology]

Conventionally, when confirming the positions of moving objects such as cars, or between a car and a central station, or when providing route guidance, analog voice communication was used using a car phone, etc. It is common to exchange information.

Alternatively, in the case of route guidance, a method is used in which route information is typed in text and checked by a human while referring to a map.

In addition, if the car has a display, etc., a device containing human route data can be handed over to the car user.
There is also a method of displaying it on a display to provide route guidance.

However, in any of the above cases, there are problems with the amount of data and compatibility of databases, and the current situation is that direct wireless communication is not performed between mobile units or between a mobile unit and a fixed station.

[Problem that the invention seeks to solve]

By the way, a communication system is being considered that uses geostationary satellites to perform two-way communication between moving objects, such as aircraft, ships, and automobiles, or with a communication center on the ground (U.S. Patent No. 4.359). .733 Specification IFN
ov, 16.1982).

Figure 7 shows an overview of this satellite communication system.
1) is a ground communication center, +2) +3) and (4) are geostationary satellites, and (5) and (6) are aircraft and automobiles as examples of mobile objects equipped with communication terminals.

In this communication system, it is possible to notify the locations of the mobile bodies (5) and (6) from the communication center to the mobile bodies (5) and (6), and to send and receive specific messages.

For example, information about the location of a moving object is commonly expressed as follows.

That is, first, the communication center (1) on the ground transmits the data via the three geostationary satellites (2) to (4).
) to send interrogation signals to the entire area that can be covered.

The mobile units (5) and (6) that received this interrogation signal transmit the signal (ID code) unique to the mobile unit to the satellites (2) to (4).
If 0 communication center < 11, the position of each mobile object (5) and (6) is determined by triangulation using a computer.
), the position information of the mobile objects (5) and (6) is transmitted to the satellites (2) to
(4) to mobile units (5) and (6). The mobile objects (5) and (6) detect the identification signal and obtain their own position information.

In this case, communication between the communication center (1) and the satellites (2) to (4) is done at 5 to 7 GHz, while the communication between the communication center (1) and the satellites (2) to (4)
Transmissions from mobile units (5) and (6) to 4) are 1.
60, reception is done at 2.5G) lx.

A terminal system installed in a mobile body includes a user unit including a keyboard and a display, and a transmitter/receiver unit, each of which is equipped with a microcomputer.

By using such a communication system using geostationary satellites, it is possible to transmit position information and route information between mobile objects or between mobile objects and a communication center as described above. .

In this case, it is preferable that the amount of information transmitted be as small as possible.

For example, when transmitting location information or route information using communication means such as low beat rate or packet transmission, the map database is not compatible, so the location information must be sent as message data in character code, or Sends information on latitude and longitude on the earth. That is what is being considered.

On the other hand, if route information is sent as a series of locations, including latitude and longitude information, the amount of information becomes enormous. Therefore, it is recommended to send only the location information of the destination and have the receiving side calculate the route and output it on the display. Alternatively, the only available method was to transmit the image information of the route map itself.

However, in the case of transmitting route information, sending only the location information of the destination as in the former case requires complicated calculations on both the sending and receiving sides, which is not desirable.

Also, when transmitting map image information like the latter,
The drawback is that it is not realistic due to the amount of information.

In view of the above-mentioned points, the present invention aims to provide a method in which the amount of transmitted information can be extremely reduced and route information can be transmitted satisfactorily. Note that the position information can be expressed as a route of the current position within a route, and this can also be considered as route information.

[Means for solving the problem] In the present invention, when transmitting route information to a receiving side that has at least branch point information and link information between branch points as a map database, the above-mentioned branch of routes Send point information.

(Operation) By transmitting branch point information, for example, a branch point number, to a route, the receiving side can obtain the route from the map database.Therefore, the amount of transmitted information can be extremely small.

〔Example〕

In this invention, the mobile units have the same map database, and also the mobile units and the communication center have the same map database. The database is as follows.

That is, FIG. 1 is a diagram for explaining the database.

In the case of this invention, the map database uses a vector format, and graphic data is expressed by nodes and links.

For example, road data is expressed as shown in FIG. 1A. In the figure, a portion surrounded by a broken line indicates, for example, an area shown as one area on both sides, and which area is identified by an area code. The points marked with ◎ are branch points, that is, nodes, and each node is given a number. O indicates an interpolation point of a road connecting nodes. A road connecting two nodes is called a link, and this link is also assigned a number. In the example shown, link 1 represents a road connecting nodes 1 and 2, link 2 represents a road connecting nodes 2 and 3, and link 3 represents a road connecting nodes 1 and 3.

And, as a memory for storing data as a map database, for example, a CD-RO? 1, this C
As data stored in the D-ROM, data of each link is stored as a link file.

For example, the file contents of link 1 are shown in FIG. 1B.

That is, first, an area code indicating the area to which link 1 belongs is filed, and then a link code indicating the link number is filed.

Then, two node numbers indicating both ends of this link are respectively filed, and after each of the two node numbers, the X and Y coordinates of each node number W within the area are stored. In the example in the figure, since it is link 1, the node number of one of the two nodes is 0001, and that is X.

The Y coordinate is (Xj, Yi) and the other node number is 0002
, its x and Y coordinates are (Xj, Yj). Following these node information, information on several interpolation points is filed as shown in the figure. Furthermore, as in the example shown in the figure, other attribute information regarding this link 1 may be filed.

Such a link file is created for each link on a CD-R.
It is filed in OM and a map database is constructed.

The mobile units or the mobile unit and the communication center each have exactly the same map database. Based on this map database, route guidance is performed as follows.

For example, in FIG. 1A, the car at point ■ on link 1 is moved from node 2 to node 3 to node 4 from this point.
- When guiding a route to point 0 through node 5, it is only necessary to sequentially send to this car only the node number in the order of the route to be guided and the data of the final destination (for example, X, Y coordinates). That is, data as shown in FIG. 2 is sequentially sent to this mobile body as a transmission signal.

First, an ID code, that is, an identification signal of each moving object such as a car to be guided, is sent. Next, the X and Y coordinates within the area of the destination (2) are sent as a mode header, in which information indicating that the transmission content is route guidance is sent. Information on node numbers in route order is then sent as route information. In this case, it is not necessary to send the information of only the node number and the x and Y coordinate information of each node. This is because the map databases are mutually common.

When the receiving side receives the transmission information sent in this way, for example, the link 1 in the area displayed on the display. Link 2゜Link 4. The route of the link 6 is displayed, for example, by blinking.

Of course, in this case, it is also possible to send other necessary information. For example, if there is a store O that you need to stop at on the way to link 4, the third node number information is followed by the store's X, for example.

Just send the Y coordinate information.

In the case of the above example, the guidance is within the same area, but of course it is necessary to send the area code when guiding from this area to another area.

However, route guidance can be provided at least by sending the node number.

Next, consider the case where current position information of a moving object is transmitted for route guidance. Generally, position information obtained by a positioning system such as LORAN-C contains errors, so after converting the position to road data, the X within the area on the road data is converted.

This is to transmit Y coordinate data. In this case, since the receiving side has the same database, the position is displayed on the road map by displaying the received X, Y data within that area.

At this time, if you send the X, Y coordinates of your current position and the information of the node number closest to your direction of travel (the x, Y coordinates of that node number are also acceptable), you can easily send your current position and direction of travel. , and the receiving side can easily display the position on the road and the direction of travel.

FIG. 3 shows a transmission signal for position and direction information in this case.

In other words, first, the ID, which is the code number of the car, etc.
The code is sent, and then the position and direction information is sent as a header. If the area is different, the area code is sent, and then the position information within that area is sent as X, Y.
Coordinate information is sent, and then node number information is sent as direction information.

Note that instead of node number information, x, y of each node
Of course, you can also send information about the i mark. This also applies to route guidance.

Furthermore, in the case of transmitting position and direction information, it is also possible to transmit the direction determined by a gyro using 3 bits.

As described above, the receiving side can easily confirm the position and direction of the transmitting side and display it on the display.

However, in the case of a system in which the receiving side can know the positions of the transmitting side and its receiving side without transmitting the position information, there is no need to transmit the position information.

Next, an example of the configuration of the receiving side that receives the above-described transmission signal will be explained with reference to FIG. 4.

That is, on the receiving side, a signal received by a receiving antenna (11) is received by a receiving section (12), the received output is demodulated by a MODEM (13), and the demodulated output is sent to a microcomputer (14). In the microcomputer (14), data is first stored in the register (15) as shown by its functional block. Then, from the stored data, the above-mentioned area code is extracted by means of extraction fi (16).

The node number etc. are big-amplified and the picked up data is transferred to the CD-ROM address generation circuit (17). The output address of this address generation circuit (17) is CD
-RAM (1B), the link information in route order is read out, and this is supplied to the video RAM address generation circuit (
19) and is converted into address data for displaying the link on the monitor screen, and this address data is sent to the video RAM (21) via the display control circuit (20).
), and links in route order are displayed on the CRT (23) as a display under the control of the CRT controller (22).

In this case, the display control circuit (20) changes the brightness on both sides of the link or node of the sent guidance route, changes the color, or displays it by blinking. .

A flowchart of the processing executed by the microcomputer (14) in this case is shown in FIG. That is, first, input data is taken in (step (101)), and area codes and/or node data are picked up from the human data (step (102)).

Next, an address on a data storage such as a CD-ROM is generated from this pickup data (step (10).
3)). Next, refer to the X and Y coordinates corresponding to the node number (step (104)). The designated area is then displayed as a map on the display (step (105)). Then, the X
, the path indicated by the Y coordinate and the link therebetween, brightens, flashes, or changes color (step (106)). The guidance route will be displayed as described above.

Note that, as shown in FIG. 6, when there are two routes from node 1 to node 4, the receiving mobile unit may decide which route to take. , as the transmission guidance route information, node numbers are sent as node 1 - node 4 - node 5, and the route display on the receiving side is the route of node 1 - node 2 - node 4 and node l - node 3 - node 4. Both of the routes may be displayed as the guide route.

Although the above description has been made as a mobile communication system using a geostationary satellite, it goes without saying that the present invention is not limited to this.

It goes without saying that the memory for storing the map database is not limited to a CD-ROM.

〔Effect of the invention〕

According to this invention, by preparing a map database consisting of node information and link information connecting two points of the nodes, it is possible to transmit route information only by node number information, and the amount of information to be transmitted is It is possible to achieve a significant reduction in Therefore, in addition to the route information, if there is a place to stop at on the way, for example, there is sufficient room to send data about that place.

Furthermore, since the amount of information to be transmitted can be very small, this invention can be easily applied to communication means with limitations such as limited transmission time, transmission band, and low bit rate. Therefore, an effective and efficient communication system can be realized.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining an example of a map database according to the present invention, Fig. 2 is a diagram showing an example of route information to be transmitted, and Fig. 3 is an example of transmission contents when transmitting position information. FIG. 4 is a block diagram of an example of a receiving device on the receiving side, FIG. 5 is a flowchart for explaining the same, FIG. 6 is a diagram showing an example of a route, and FIG. , is a diagram showing an example of a two-way communication system using a geostationary satellite. (18) is a CD-ROM as an example of a memory that stores a map database.

Claims (1)

[Claims] A method for transmitting route information comprising transmitting information on branch points in the order of the route when transmitting route information to a receiving side having at least information on branch points and information on links between branch points as a map database.