JP2935617B2 - Road-to-vehicle communication 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 road-vehicle communication device for transmitting information outside a vehicle to a vehicle in a navigation system, and more particularly to a memory for storing beacon information in the present invention.

[0002]

2. Description of the Related Art Conventionally, in a navigation system as a technology in such a field, information contents from the outside stored in a unique storage memory, for example, current position information, various kinds of guidance information, regulation information, traffic congestion information and the like are also stored. At the same time, processing for correcting the current position and drawing the traffic jam information display on the display medium is performed. The external information is a road-to-vehicle communication device (RACS: Road Automobile C).
ommunication System).

FIG. 4 is a diagram schematically showing a conventional road-vehicle communication device. As shown in FIG. 1A, a receiver of a road-vehicle communication device mounted on a vehicle receives the external information from a beacon installed on a road. This beacon is a spot communication road device installed every 300 m or more on the road.

[0004]

However, the conventional road-to-vehicle communication apparatus has the following problems. FIG.
As shown in (b), the information received by the receiver 1 of the road-to-vehicle communication device mounted on the vehicle together with the road information formed by the navigation system 2 includes, for example, an LCD (L).
The receiver 1 and the navigation system 2 have their own memories, and the receiver 1 and the navigation system 2 use communication means (such as serial communication) between the respective memories. Has been transferred to the navigation system 2. By the way, since the vehicle is moving at high speed, it is required to promptly process and display the information received from the beacon. However, when the communication volume between the memories increases, the communication between the receiver 1 and the navigation system 2 becomes difficult. There is a problem that it takes time and cannot display received information quickly.

Accordingly, the present invention has been made in view of the above problems,
It is an object of the present invention to provide a road-vehicle communication device capable of quickly displaying information received from a beacon.

[0006]

In order to solve the above-mentioned problems, the present invention has a receiver for receiving external information, and supplies the external information to a navigation system for displaying geographic information of a vehicle. A memory shared with the receiver and the navigation system, wherein the external information is stored in the memory (4) during reception by the receiver, and simultaneously reading from the memory by the navigation system is prohibited; After the reception by the receiver, the reading to the memory by the navigation system is permitted.

[0007]

According to the road-vehicle communication apparatus of the present invention, a memory shared by the receiver and the navigation system is provided, and the external information is stored in the memory (4) during reception by the receiver, and the navigation is simultaneously performed. Reading out to the memory by the system is prohibited, and reading out to the memory by the navigation system is allowed after reception by the receiver, so that data communication performed between the receiver and the memory of the navigation system as in the past can be performed. The required time can be reduced, and the memory capacity can be further reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a road-vehicle communication device according to an embodiment of the present invention. In the road-to-vehicle communication device shown in this figure, the components different from those in FIG. 4 are that the receiver 1 and the navigation system 2 of the road-to-vehicle communication device have memories in FIG. Is to have. This memory 4 is a dual port RAM (Ran
dom Access Memory). Note that the receiver 1 controls reading of the navigation system 2 from the memory 4.

FIG. 2 is a diagram for explaining the control signal DPE of the navigation system 2. The receiver 1 of the road-to-vehicle communication apparatus receives beacon information data of a plurality of frames (three frames will be described as an example) as shown in FIG. As shown in (a), when beacon data is newly received, it becomes “L (low)”, and when reception is completed, “H (hig)
h) ”. When the control signal DPE is“ L ”, the navigation system 2 is prohibited from reading data into the memory 4. On the other hand, when the control signal DPE is“ H ”, the navigation system 2 stores the memory. Therefore, when the control signal is "L", the memory 4 stores the data from the receiver 1, and when the control signal is "H", the data stored in the memory 4 is transmitted to the navigation system 2. Output can be performed, and the display unit 3 performs display drawing according to the content.

FIG. 3 is a diagram for explaining a series of operations of the road-vehicle communication apparatus according to the embodiment of the present invention. In step 1 shown in the figure, the road-to-vehicle communication device determines whether beacon data reception has started. In step 2, if the determination in step 1 is "YES", the control signal DP
E “L” is output to the navigation system 2, thereby prohibiting the navigation system 2 from reading data into the memory 4.

In step 3, the receiver 1 determines, for example, whether the data reception of the frame 1 has been completed.
In step 4, the judgment in step 3 is "YE
If "S", a process of writing to the memory 4 is performed. Step 5
In, the receiver 1 determines, for example, whether the reception / writing of the beacon data in frames 1 to 3 is completed. This determination is made by the head of each frame.

In step 6, if the determination in step 5 is "YES", the control signal DPE is changed from "L" to "H". As a result, the navigation system 2 is permitted to read the data into the memory 4, and the navigation system 2 can perform beacon information display processing. Thus, according to the present embodiment, even if the information from the beacon increases, there is no need to perform data communication between the receiver 1 and the navigation system 2 as in the related art, and the time from the start of beacon reception to the display can be shortened. And memory capacity can be reduced.

[0013]

As described above, according to the present invention, a memory shared by the receiver and the navigation system is provided, and during reception of the receiver, reading to the memory by the navigation system is prohibited. Since reading to the memory by the navigation system is permitted after reception, the time required for data communication performed between the receiver and the memory of the navigation system as in the related art can be reduced, and the memory capacity can be further reduced. Reduction becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a road-vehicle communication device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a control signal DPE of the navigation system 2.

FIG. 3 is a diagram illustrating a series of operations of the road-vehicle communication device according to the embodiment of the present invention.

FIG. 4 is a diagram schematically showing a conventional road-vehicle communication device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Receiver 2 ... Navigation 3 ... Display part 4 ... Memory

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G08G 1/0969 G08G 1/09

Claims (1)

(57) [Claims] 1. A road-to-vehicle device comprising a receiver (1) for receiving external information and supplying said external information to a navigation system (2) for displaying geographical information of the vehicle, comprising: A memory (4) shared by the navigation device (1) and the navigation system (2), wherein the external information is stored in the memory (4) during reception by the receiver (1), and simultaneously the memory by the navigation system (2) is provided. A road-vehicle communication apparatus characterized in that reading to (4) is prohibited, and reading from the memory (4) by the navigation system (2) is permitted after reception by the receiver (1).