JPH0196796A - Road traffic information system - 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 road traffic information system, and particularly to a system suitable for providing traffic information to land moving bodies such as automobiles.

[Conventional technology]

2. Description of the Related Art In recent years, various systems for transmitting traffic information to vehicles and the like using a single communication means have been proposed, and studies have been made to put them into practical use. Traffic information is information related to traffic jams, such as the name of a congested route, the location and length of a congested traffic jam, or traffic regulation information, and often changes dynamically.

A general example of such a system will be explained using FIG. 5. In FIG. 5, traffic information is simultaneously broadcasted in the form of a digital signal on an FM broadcast signal using a method of multiplexing it with a normal audio signal. Raw traffic information is provided from outside, and the center 11 collects, processes and edits the information.
is input.

Information is collected over a wide area, including the broadcast service area. The information processed by the center 11 is sent to the multiplexing device! 1
After multiplexing with the audio signal input to the transmitter 13.2, the transmitter 13. A signal is radiated into the air via the antenna 14. Information is divided into blocks and transmitted in the form of digital data, as shown in FIG. 6(A), for example. In the case of traffic congestion information, the route name, traffic congestion section, traffic congestion time, etc. are sent in coded form as shown in (B). On the other hand, on the vehicle 3 side, the equipment configuration shown in FIG. 5 receives the radiated radio waves, decodes the information, and processes it appropriately.

After processing, it is communicated to the driver etc. by display means. The radio waves emitted from the ground antenna 14 are transmitted to the vehicle antenna 3.
0 is received by the receiver 31 and demodulated by the controller 3.
4 is input. The control device 34 stores this information in its internal memory.

Since the information from the ground covers a very wide range, the control device 34 needs to appropriately select and process the information and provide it to the driver. Since the traffic information is encoded, it must be deciphered by comparing it with the vehicle's own location. To do this, it is first necessary to know where the vehicle 3 is located (route name, place name, location, etc.). Therefore, a means 32 for positioning and a database 33 are required. The database 33 is a compact disk read only memory (CD-ROM).
), etc., and stores map information, road network information, etc. For example, the control device 34 accesses the database 33, pulls out map information, superimposes the current location and information on traffic jam points, and displays the information on the cathode ray tube (CRT) 3.
5.

In other words, on the ground side, it is very economical as it only requires adding some equipment to the existing broadcasting equipment.
Many devices are required on the vehicle side.

A similar system is, for example, Jikai No. 61-163499.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology imposes a large burden on the user side, that is, on-vehicle equipment, and it is difficult for general users to easily enjoy the benefits of the system. Another technical problem is data errors due to so-called multipath fading. Introducing diapersity technology to reduce multipath fading,
In order to reduce the negative effects of data errors, it is necessary to introduce error detection and correction technology, which further increases the burden on in-vehicle equipment.

The present invention has been made in view of the above-mentioned problem, namely, that in-vehicle systems become large-scale in road information systems, and it is an object of the present invention to provide a system that makes it possible to collect sufficient information even with simple in-vehicle equipment. The purpose is to

[Means to solve problems]

The above purpose is to install multiple small broadcasting stations for relaying around roads, and to have these relay stations have small-scale databases.
This is achieved by selectively processing the information and then rebroadcasting it.

[Effect]

Relay stations collect and update traffic information by constantly receiving broadcast radio waves, and based on their built-in database, they extract information related to the area they are in charge of and broadcast it to vehicles. .

By doing this, the data from the relay station can be directly used on the vehicle side, so a database or the like for sorting data can be omitted.

Furthermore, since the relay station is a fixed station, there is very little possibility that multipath fading will become a problem, and the receiver becomes simpler. Furthermore, communication from the relay station to the on-vehicle equipment is line-of-sight communication, which reduces the possibility of multipath fading, which simplifies the on-vehicle receiver.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. Although FIG. 1 shows a system using an existing FM broadcasting station, it is also possible to use other communication or broadcasting means. As already explained, the collected traffic information is edited at the central station 11, and after multiplexing the audio information (multiplexer 12), it is broadcast using the transmitter 13 and the antenna 14.The service area is approximately the same as the audio service area. It's the same. -Multiple relay stations are installed on the old road side.
It is designed to constantly receive information from broadcast stations. Radio waves from a broadcasting station are received by an antenna 20 and input to a repeater 2. The relay 2 stores data information internally,
At the same time, information on the area covered by the relay station is extracted from the data, and the transmission means and antenna 2 are updated.
Sends information via 1.

The communication area 5 in one relay station may be determined as appropriate depending on the amount of information and data transmission speed.

If the communication area is appropriately narrowed, position determination can be performed with higher accuracy. The repeater 2 and the communication method will be described in detail later.

When the vehicle 3 enters the area 5 where the relay station communicates with the vehicle-mounted device, radio waves from the antenna 21 can reach the vehicle and information can be received. The antenna 40 detects radio waves from the road and sends them to the on-vehicle control device 4. Then, the in-vehicle control device 4 demodulates the data and sends the data to the display device 46 for display.

FIG. 2 shows a diagram illustrating details of the relay station.

A signal from an FM broadcast station is received by an antenna 20, guided to a receiving section 22, where it is amplified and filtered.

Furthermore, the demodulation circuit 23 demodulates and reproduces the data.

A central control unit (CPU) 26 that performs overall control is
It operates according to a program stored in a read-only memory (ROM) 24 and transfers output data from the demodulation circuit 23 to a random access memory (RAM) 25.

The CPU 26 further accesses the database 23 and
Retrieves information about the point where the repeater is located; this information includes point name, coordinates, route name and number, associated route name and number, etc.

An in-vehicle database needs to cover a wide range and require a huge amount of data (for example, 500MB), but in the case of a relay station, since it is fixed, only nearby data is required.Therefore, as a medium, CD -IC(7) ROM is more practical and reliable than ROM etc.

The CPU 26 refers to the data on the database 23, extracts related information from the data on the RAM 25, and edits it as data to be transmitted to the vehicle. An example is shown in FIG. Such edited data is modulated by a modulator 27, amplified by a transmitting circuit 28, guided to an antenna 21, and radiated into space. As this communication method, if the specifications can be satisfied at a transmission rate of about 20 kilobits/second or less, an inductive radio method is preferable for reasons such as cost. If the amount of information to be sent is large, use U.
It is also possible to use radio waves in the HF band.

Figure 4 shows a road antenna 21 showing the configuration of the main equipment.
The electromagnetic waves emitted from the vehicle are detected by an on-vehicle antenna 40, amplified and filtered by a receiving circuit 41, and then data is reproduced by a demodulating circuit 42 and taken into the CPU 43. The captured data is stored in RAM 45. C
PU43 operates according to the program stored in ROM44. The CPU 43 creates display data from the received data RAM 45 and sends it to the display device 46 for display.

As described above, even when compared with the conventional example shown in FIG. 5, the on-vehicle device clearly has fewer components and is simpler. In particular, the advantage of being able to omit the database 33 using an expensive CD-ROM is significant.

According to this embodiment, by installing a relay station and having the data processed, the burden on the vehicle-mounted side can be reduced, so that the vehicle-mounted device can be simplified.

Furthermore, if you compare the number of relay stations installed within a single FM broadcasting station service area (within a few hundred) and the number of vehicles used within the area (over a million), it is clear that
The economic efficiency of the entire system can be improved.

〔Effect of the invention〕

As described above, according to the present invention, sufficient information can be collected even with a simple in-vehicle device.

[Brief explanation of the drawing]

Fig. 1 is a system configuration diagram showing one embodiment of the present invention;
The figure is a detailed circuit configuration diagram of the relay station in Figure 1, Figure 3 is a developed view of information content display transmitted from the relay station, Figure 4 is a circuit diagram explaining the configuration of the on-vehicle device in Figure 1, and Figure 5 is a circuit diagram explaining the configuration of the in-vehicle device in Figure 1. The figure is a conventional system configuration diagram, and FIG. 6 is a developed view of information content display in FIG. 5. 2... Repeater, 11... Center, 12... Multiplexer. rate 3 figure

Claims (1)

[Claims] 1. In a road traffic information system that provides encoded traffic information to moving objects such as vehicles using broadcasting or communication means that have a wide service area, collected external information is A road traffic information system that transmits information via multiple relay small broadcast stations installed in the surrounding area. 2. The road traffic information system according to claim 1, wherein the relay station has a database and is configured to select and process information and then rebroadcast it. 3. In a road traffic information system that provides encoded traffic information to moving objects such as vehicles using broadcasting or communication means that have a wide service area, means for extracting information regarding a specific area from the service information; , characterized in that a relay station having means for editing the extracted information, means for modulating the edited information, and means for transmitting the modulated signal to a limited area is installed around the road. Road traffic information system. 4. The road traffic information system according to claim 3, wherein a plurality of said relay stations are provided. 5. The road traffic information system according to claim 4, wherein the relay station is located on a side road of a road.