JPS6343028B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a data transmission method between the ground and the on-vehicle, which activates transmission to the on-vehicle using a trigger signal from the ground and receives vehicle data from the on-board vehicle. This relates to a data transmission method that stops the transmission start on the vehicle after receiving the data.

A conventional system of this type is shown in FIG. Figures a, b, c, and d show on-vehicle transmission data, on-vehicle reception data, ground-side transmission data, and ground-side reception data, respectively. In the figure, 1 is a trigger signal that starts transmission to the on-vehicle device on the vehicle, 11 is a trigger signal received on the on-vehicle side, and 2
is vehicle data, 21 is ground-received vehicle data received by a roadside device on the ground, 3 is data containing a confirmation code that conveys to the vehicle that vehicle data has been received on the ground, and 31 is confirmation received on the vehicle. This is data that includes a code.

Next, the operation will be explained. Data transmission between onboard and ground will be explained with reference to FIG. It is now assumed that a trigger signal 1 is being transmitted at regular time intervals from a roadside device installed on the ground. At this time, if there is a vehicle within the communication area, the on-vehicle device installed on the vehicle receives this trigger signal 1 as the on-vehicle reception trigger signal 11, activates the on-vehicle device to transmit at that timing, and transmits the vehicle data 2. to the ground. The roadside device on the ground receives this ground received vehicle data 21, returns it after processing the data, and transmits data 3 including a confirmation code to the vehicle in order to notify the vehicle that the vehicle data 2 has been accurately received. . When the on-vehicle device on the vehicle receives the data 31 including the confirmation code, the on-vehicle device on the vehicle stops transmitting, so even if it receives the subsequent trigger signal 11 from the ground, it does not transmit the vehicle data 2. This means that communication between the vehicle and the ground has been completed. Furthermore, if the vehicle data 2 received on the ground is inaccurate, such as missing data, data 31 containing a confirmation code indicating that the data is incomplete is sent back from the ground to the vehicle. In this case, since communication between the vehicle and the ground is incomplete, it is assumed that the on-board device on the vehicle will not stop transmitting. Furthermore, one period of data transmission between onboard and ground is _T1 shown in FIG.

Conventional data transmission systems are configured as described above, so if communication between on-vehicle and ground is incomplete, the on-vehicle device must receive the trigger signal from the ground again, and the trigger signal, When the data length of vehicle data and data including confirmation code is long, when the communication area is narrow, when the line quality of the data transmission line between onboard and ground is poor, that is, when the data reception rate is poor, However, there were drawbacks such as the inability to communicate between the vehicle and the ground.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it transmits a trigger signal containing car number information from the ground to the top of the car, receives this signal on the car, and calculates the car number. When the information does not match your vehicle number, the vehicle data including the vehicle number is sent to the ground, this signal is received on the ground, processed, and returned.
A trigger signal containing the car number is sent back to the car, and this car number is compared with your own car number, and when they match,
By stopping the transmission activation on the vehicle and using the trigger signal containing this vehicle number as a trigger signal for other vehicles within the same communication area, the data collection cycle of vehicle data received on the ground side is completed. The purpose is to provide a data transmission method that can reduce the time required.

An embodiment of the present invention will be described below with reference to the drawings. In Fig. 2, 1 is a trigger signal transmitted from the ground to the vehicle, 11 is a trigger signal received on the vehicle, 2 is vehicle data including a vehicle number that can identify the vehicle, and 21 is received on the ground. vehicle data,
22 is vehicle number data included in vehicle data that is on-vehicle transmission data, and 23 is vehicle number data that is the same as the vehicle number data 22 in the vehicle data received on the ground. 4 is a trigger signal from the ground including the vehicle number data 22; 41 is a trigger signal received on the vehicle; 4;
2 is the same car number data as the car number data 22, and 43 is car number data received on the car.

Next, the operation will be explained with reference to FIGS. 2a to 2d.

It is now assumed that a trigger signal 1 is being transmitted to the vehicle from a roadside device installed on the ground at fixed time intervals.

If there is a vehicle within the communication area, this trigger signal 1
is received as the trigger signal 11, so if the car number information therein is 0 or the car number of another car, at this timing, the on-board device installed in the car is activated to transmit and identify the vehicle. Possible car number data 22
The vehicle data 2 including the information is transmitted to the ground. On the ground, vehicle data 21 that includes vehicle number data 23 that is the same as vehicle number data 22 is received, so after processing this, the roadside machine on the ground returns the vehicle data 2 that includes the vehicle number data 22. , in order to notify the vehicle that the trigger signal 4 has been received, the trigger signal 4 containing the same vehicle number data 42 as the vehicle number data 22 is transmitted to the vehicle. On the vehicle, the vehicle number data 42 is received as the vehicle number data 43, so if the vehicle number data 22 and the vehicle number data 43 completely match, it is determined that the communication between the vehicle and the ground has been completed, and the vehicle number data 42 is received as the vehicle number data 43. The in-vehicle device stops transmitting and thereafter does not transmit the vehicle data 2 even if it receives a trigger signal received on a vehicle within this service area. At the same time, when another vehicle within the same communication area as the vehicle receives the trigger signal 4 on the ground, the on-vehicle reception trigger signal 41 containing the vehicle number data 43 is received on the vehicle, and the vehicle number data of the vehicle itself is received. Since this vehicle number data 43 is different, it is determined that this vehicle has simply received the trigger signal 11, and the vehicle data is transmitted to the ground.

In this case, one cycle of on-vehicle-to-ground communication corresponds to _T1 in FIG. 2, and is no different in terms of time from the conventional system. However, one cycle of data collection on the ground side corresponds to T ₂ in FIG. 2, and is shorter than the conventional method by the time T ₂ compared to T ₁ .

In the above embodiment, the trigger signal is one type, and when on-vehicle data is correctly received in the car number information part of the trigger signal, the car number information is included in the car number information of the next trigger signal and sent. However, there are two types of trigger signals: one without car number information and one with car number information.Normally, a trigger signal without car number information is sent out, and only when on-vehicle data is received. Other methods of sending out trigger signals including the car number information can also produce the same effects as the above embodiment.

As described above, according to the present invention, the vehicle number data is inserted into the ground transmission trigger signal, and if the vehicle number data matches the own vehicle number data on the vehicle, the transmission activation on the vehicle is stopped. Because of this configuration, the time required to collect vehicle data through transmission and reception on the ground side is shorter than with conventional methods, and the effect is that it is possible to communicate with other vehicles within the same communication area more quickly. There is.

In particular, when communicating between onboard vehicles and the ground using guided radio, the service area is narrow, so multiple moving objects can communicate in a short time while driving.
This has the effect of efficiently transmitting data.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional on-vehicle-to-ground data transmission system, and FIG. 2 is a diagram showing a data transmission system according to an embodiment of the present invention. In the figure, 1...trigger signal, 11...trigger signal received on the vehicle, 2...vehicle data, 21...vehicle data received on the ground, 22...vehicle number data transmitted on the vehicle, 23...vehicle number data received on the ground, 3...confirmation code. Data included (on the ground side), 31... Data including confirmation code (on the vehicle side), 4... Trigger signal (including vehicle number information), 41... Trigger signal received on the vehicle (including vehicle number information), 42... Vehicle number transmitted on the ground Data, 43... Vehicle number data received on the vehicle. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In devices that transmit data between an on-vehicle device within a communication area and a roadside device on the ground, the on-road device sends a trigger signal containing vehicle number information at regular intervals, and the onboard device transmits the trigger signal. When the above trigger signal is received and the car number information included in the above trigger signal matches the own car number, the in-vehicle device stops transmitting and starting in response to the trigger signal received at a predetermined time thereafter, and if the car number information included in the above trigger signal matches the own car number, For example, data including its own vehicle number information is transmitted to the on-road device, and the road device that receives the above data is instructed to include the vehicle number information included in the data from the vehicle in the trigger signal it sends thereafter. A data transmission method characterized by the following.