JP3324519B2 - In-vehicle wireless device and road-vehicle communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides real-time road and driving environment information to vehicles from roadside systems by using bidirectional communication between vehicles and roadside systems in road traffic. In particular, the present invention relates to a technology that warns the danger in advance when a danger is predicted and assists a driver in determining a driving operation.

[0002]

2. Description of the Related Art In recent years, the sophistication of road traffic systems worldwide (Intelligent Traffic Systems: Intelligent)
There is a growing momentum for development of Transport System (hereinafter referred to as ITS). In Japan, the promotion of ITS was decided in February 1995 by the government's “Basic Policy for the Promotion of an Advanced Information and Telecommunications Society”. An “Implementation Guideline” has been issued, which lists 11 promotion measures and 9 development areas. Here, the nine development fields are advanced navigation, automatic toll collection system, safe driving support, traffic management optimization, road management efficiency, public transportation support, commercial vehicle efficiency, pedestrians And support for emergency vehicle operation. Among them, safe driving assistance includes technology that provides drivers with information on roads and driving environments, or that warns of danger and assists drivers in determining driving operations.By further developing this technology, It is intended to realize safe and smooth automatic driving. Currently, experiments on automatic driving, which is the ultimate goal of safe driving support, have been conducted on vehicles using the test course of the Public Works Research Institute of the Ministry of Construction and actual roads around Komoro Interchange on Joshinetsu Expressway. However, the pattern has been reported on television, newspapers, and the like, and awareness of automatic driving of vehicles is spreading to the world. The outline of the automatic driving control system of the vehicle is described in Asahi Shimbun (19)
96-9-28 morning edition), page 29, "A car ran along the electronic path", Yomiuri Shimbun (1996-10-29 morning edition), page 26
See pages 27 to 27, "Realizing Japan's Dream Autonomous Driving Vehicle with Advanced Development".

A danger warning system which provides a driver with information on a road and a driving environment in real time from a road side system to a vehicle or warns a danger to assist a driver in determining a driving operation. Is a technology that should be the first step in supporting safe driving. To realize this,
Information communication means for performing two-way communication between the vehicle and the roadside system is required.

FIG. 12 shows a basic configuration of a danger warning information communication means. In the figure, the lane 1 is divided into a plurality of sections in the vehicle traveling direction, and each of the divided sections is called a communication zone 2. Two-way communication is performed between the on-vehicle wireless device 4 attached to the roof of the running vehicle 3 existing in the communication zone 2 and the roadside wireless device 5 installed on the roadside for each communication zone 2. The roadside apparatus 5
Are the roadside antenna 5a, the transmitting / receiving unit 5b, and the communication control unit 5
c and is connected to the roadside network 6 via the communication control unit 5c.

Next, FIG. 13 shows the internal configuration of the on-vehicle wireless device 4. In the figure, reference numeral 7a denotes an on-vehicle transmission antenna for transmitting radio waves facing the roadside antenna 5a, 7b denotes an on-vehicle reception antenna, 8 denotes a reception wave received by the on-vehicle reception antenna 7b, and 9 denotes a reception wave 8 input and amplified. , A receiving unit that performs detection, 10 is a received data signal detected by the receiving unit 9, 11
Is a communication control unit which is connected to an in-vehicle upper system such as an in-vehicle LAN via an in-vehicle bus 21 and controls communication for transmission and reception; 12 is a transmission data signal output from the communication control unit 11; A transmitting unit that performs modulation and amplification, a transmitting wave 14 output from the transmitting unit 13, and a transmitting antenna 7 a that radiates the transmitting wave 14 into space. In addition,
Here, the in-vehicle transmitting antenna 7a and the in-vehicle receiving antenna 7b
Are collectively referred to as an in-vehicle antenna 7.

Now, an example will be described in which an actual danger warning system is configured by using a mechanism for performing two-way communication between roads and vehicles configured as described above. FIG. 14 shows an example of the system. The figure shows an example in which a road in which a one-way one-way road is opposed forms a sharp curve with poor visibility. In the figure, the communication zone 2 formed by the roadside antenna 5a is continuously arranged. The example of FIG. 14 shows a case where the obstacle 24 has fallen at the end of the curve and warns the driver of the vehicle in advance of this. In the figure, a warning message is transmitted from the roadside antenna 5a of the roadside wireless device 5 to the vehicle 3 before the vehicle 3 approaches the curve from the roadside, the warning message is received by the onboard wireless device 4, and the result is notified to the driver. Accordingly, the driver can decelerate sufficiently before entering the curve, and an accident can be prevented.

Here, a warning issued by the roadside apparatus 5 needs to be issued to the vehicle 3 traveling outside the curve, and it is necessary to notify a vehicle in the opposite lane that has already exited the inside of the curve. Absent. Rather, for a driver of a vehicle in the oncoming lane, even if a meaningless warning is received, it may even be considered that driving is hindered. Therefore, the communication zone 2 formed by the roadside wireless device 5 needs to irradiate only one lane as shown in FIG. 14 so as not to leak into the opposite lane. On the other hand, no matter where the vehicle 3 travels in the lane, it is necessary to minimize the unevenness of the coverage area in the width direction of the one lane so that the warning information can be reliably received.

Therefore, in the communication zone 2 formed by the directivity of the roadside antenna 5a, the lane in the traveling direction must be set to the full width of the lane, and the reception sensitivity of the oncoming lane must be lower than the receiving sensitivity of the on-vehicle wireless device 4. is there. On the other hand, the communication zone includes variations in the roadside antenna 5a, variations in the transmission power of the transceiver 5b of the roadside wireless device 5, changes over time,
It is affected by many fluctuation factors such as the mounting direction and variation of the receiving antenna 7b of the on-vehicle wireless device, and the variation of the sensitivity of the receiving unit 9. If the communication zone is narrowed and set so as to compensate for them, a dead zone occurs in the communication zone in the traveling direction, and necessary warning information cannot be received.

[0009]

In the conventional road-to-vehicle communication system as described above, if a sufficient forward communication zone is provided, a meaningless warning is received for a driver of a vehicle traveling in the opposite direction. This can result in a system that is more detrimental to safe driving. Further, if the communication zone is narrowed to avoid this, there is a problem that a necessary warning may not be received by the vehicle-mounted device.

The present invention has been made to solve such a problem, and meaningless communication is performed for a vehicle traveling in the opposite direction while forming a sufficient communication zone in the forward direction. There is not to be.

[0011]

According to a first aspect of the present invention, an on-vehicle wireless device communicates with a roadside wireless device provided on a road.
In a vehicle-mounted wireless device that performs
Antenna and two antennas from the roadside device
And the comparison result and the roadside apparatus
Of the vehicle based on the layout relationship between the vehicle and the lane on the road
A direction determination unit for specifying the direction,
How vehicles travel on roads using differences in propagation path lengths of radio waves
The direction is specified.

[0012] In addition, a vehicle-mounted wireless device according to the second invention comprises:
In the first invention, the direction determination unit includes two antennas.
Compare the phase of each received signal and receive from the comparison result
The arrival direction of the signal is determined.

[0013] Further, the on-vehicle wireless device according to the third aspect of the present invention comprises:
In the first invention, one of the two antennas is
Is located in front and the other is located behind the vehicle
is there. Further, the in-vehicle wireless device according to the fourth aspect of the present invention has a third aspect.
In the present invention, two arcs are determined based on the determination result of the direction determination unit.
Of the received signals from the front of the vehicle
Notify the driver when the signal of the advanced side is received
Of the signals received by each of the two antennas after the vehicle
Driver receives a signal on the side with advanced phase from
Is provided with a notification control unit that does not notify the user. Also,
According to a fifth aspect of the present invention, in the vehicle-mounted wireless device according to the first aspect,
Two antennas, one located on the left side of the vehicle, the other
The other is disposed on the right side of the vehicle at a distance. Ma
Further, the in-vehicle wireless device according to the sixth invention is the same as that of the fifth invention.
And the roadside device is located on the left side in the traveling direction of the lane.
When traveling on a road, 2
Of the signals received by each of the two antennas from the left of the vehicle
When the signal on the side with advanced phase is received, the driver
Of the received signal of each of the two antennas
When the signal with the phase advanced from both right is received
A notification control unit that does not notify the driver is provided. Ma
Further, the in-vehicle wireless device according to the seventh invention is the same as the first invention.
And the direction determination unit receives the received signal of each of the two antennas.
Based on the baseband signal demodulated from the
This is to compare the communication signals. Also, the eighth
The road-to-vehicle communication system according the invention, the first to seventh calling
In the traffic lane to communicate with vehicles on the lane
The two-way road is divided according to the direction of travel for each width direction,
And the road per traveling direction of the lane is divided into a plurality of communication sections, each the communication section transmits and receives control information to and from a plurality of vehicles existing independently of the number of communication intervals, the same number exists and the number of communication sections It comprises a plurality of roadside wireless devices and an in-vehicle wireless device that communicates with the roadside wireless devices.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a system showing a first embodiment of the present invention. In FIG. 1, reference numerals 1 to 3 and 5 to 6 are the same as those of the conventional system, and reference numeral 4 denotes an in-vehicle wireless device mounted on the vehicle 3. The internal configuration is as shown in FIG. In FIG. 2, reference numerals 7 to 14 and 21 are the same as those of the conventional in-vehicle wireless device shown in FIG. 13, 15 is a second in-vehicle receiving antenna for receiving radio waves facing the roadside antenna 5a, and 16 is a second in-vehicle receiving antenna. A received wave received by the receiving antenna 15, 17 is a phase comparator for receiving the received waves 8 and 16 and comparing the phase difference between the two, 18 is a phase comparison output of the phase comparator, and 19 is a phase comparison output 18. A direction determining unit for binary-determining whether the direction of arrival of the radio wave is ahead or behind the vehicle.
9 is the direction determination result.

Next, the operation will be described. Although the format of the radio wave transmitted by the roadside antenna in FIG. 1 is not particularly limited, here, for simplicity, ASK (Am
Considering a Pitch Shift Keying modulated wave, a radio wave as shown in FIG. 3 is used. FIG.
In the received waves 8 and 16 shown in FIG.
Represents a large amplitude period in the ASK modulation wave, and "0" of data corresponds to a small amplitude period. FIG.
Is an enlarged part of the time axis of FIG. The received waves 8 and 16 received by the in-vehicle receiving antennas 7b and 15 attached to the front and rear portions of the roof of the vehicle 3 are:
As illustrated in FIG. 5, there is a difference in the propagation distance depending on the arrival direction of the radio wave, and the phase is accordingly different.
When the phase of 8 is advanced, it is understood that the roadside apparatus is ahead, and when the phase of the received wave 16 is advanced, the roadside apparatus is behind. In this case, the communication control unit decodes the content of the direction determination result 20 and does not issue an unnecessary warning to the driver when recognizing that the information is for the oncoming lane.

Next, FIG. 6 shows an operation diagram of the on -vehicle wireless device and the road-vehicle communication system formed by disposing the roadside wireless device. In the figure, the communication zone 2 by the roadside antenna 5a of the roadside wireless device 5 covers the entire area in the width direction of the lane in the traveling direction, and a part thereof is set so as to protrude into the oncoming lane. Now, when the roadside apparatus 5 notifies the driver of the vehicle 3 of the obstacle 24 at the end of the corner, the danger warning information is obtained because the communication zone covers the entire width of the traveling lane. The vehicle 3 is reliably notified. Although there is a possibility that the vehicle traveling in the oncoming lane may receive the danger warning information, as described above, by recognizing that the information comes from behind the vehicle, no unnecessary warning is issued to the driver.

Embodiment 2 FIG. FIG. 7 is a diagram showing a mounting state of a vehicle-mounted antenna according to a second embodiment of the present invention, wherein a vehicle-mounted antenna 7b and a second vehicle-mounted receiving antenna 15 of the vehicle-mounted wireless device of FIG. FIG. The example of FIG. 7 is a case where a leaky waveguide is used as a roadside antenna. When radio waves are radiated from the side of the road as described above, both antennas mounted on the left and right sides of the roof of the vehicle are used. By comparing the phases of the received waves, it is possible to determine whether the danger warning information is for the own vehicle or for the vehicle on the opposite lane.

Next, the operation will be described. FIG. 8 shows a car
FIG. 3 is an operation diagram of the on -board wireless device and the road-vehicle communication system .
In the figure, the communication zone 2 by the roadside antenna 5a of the roadside wireless device 5 covers the entire area in the width direction of the lane in the traveling direction, and a part thereof is set so as to protrude into the oncoming lane. Now, there is an obstacle 24 at the end of the corner,
When the roadside apparatus 5 notifies the driver of the vehicle 3 of this, the danger warning information is reliably notified to the vehicle 3 because the communication zone covers the entire width direction of the traveling lane. Although there is a possibility that the vehicle traveling in the oncoming lane may receive the danger warning information, as described above, by recognizing that the information comes from the right side of the vehicle, no unnecessary warning is issued to the driver. As shown in FIG. 9, the communication zone 2 by the roadside antenna 5a of the roadside wireless device 5 is:
The same applies to the case where the signal is given from the side by the roadside antenna 5a.

Embodiment 3 FIG. 10 is a diagram showing a configuration of an in-vehicle wireless device according to a third embodiment of the present invention. In the drawing, reference numerals 7 to 21 are the same as those in FIG. Reference numeral 22 denotes a receiving unit that receives the second received wave 16 and receives and demodulates the received signal. Reference numeral 23 denotes a received data signal demodulated by the receiving unit 22.

Next, the operation will be described. The configuration of the roadside system is as shown in FIG. Regarding the format of the radio wave transmitted by the roadside antenna, an ASK (Amplitude Shift Keyin) is used here for simplicity.
g) Consider a modulated wave and assume that a radio wave as shown in FIG. 11 is emitted. In the received waves 8 and 16 shown in FIG. 11, "1" of data corresponds to a large amplitude period and "0" of data corresponds to a small amplitude period in an ASK modulated wave. The received waves 8 and 16 received by the in-vehicle receiving antennas 7b and 15 attached to the front and rear portions of the roof of the vehicle 3 have different propagation distances depending on the direction of arrival of radio waves as illustrated in FIG. The phases differ accordingly. Here, reception data signals 10 and 23 obtained by demodulating the reception waves 8 and 16 by the reception units 9 and 22, respectively, are input to the phase comparator 17. When the phase of the reception data signal 10 is advanced, it is understood that the roadside apparatus is ahead, and when the phase of the reception data signal 23 is advanced, the roadside apparatus is backward. In this case, the communication control unit decodes the content of the direction determination result 20 and, when recognizing that the information is for the oncoming lane, does not issue an unnecessary warning to the driver. In Embodiment 3 of the present invention,
Instead of comparing the phases of the carrier waves of the received signal as they are, it is possible to compare baseband signals that are easy to process. The in-vehicle antenna is connected to the front and rear of the vehicle.
But the roadside antenna is located to the left of the road
In some cases, the vehicle-mounted antenna is
By placing them on the left and right sides, a similar effect can be obtained.
It goes without saying that it can be obtained.

[0021]

According to the first to fourth and eighth aspects of the present invention, it is determined on the vehicle side whether the danger warning information transmitted from the roadside antenna is for the own vehicle or for the oncoming lane. By providing the function of discriminating, there is an effect that the setting condition of the communication zone by the roadside antenna is relaxed, and the warning information for the oncoming lane can avoid the driver from being bothered.

Also, the first, second, fifth, sixth, and first
According to the invention of the eighth aspect , the roadside antenna for transmitting the danger warning information is a leaky waveguide or the like, and even when radio waves arrive from the side of the road, the danger warning information transmitted from the roadside antenna is transmitted to the vehicle side. By providing a function of determining whether the vehicle is for the own vehicle or for the oncoming lane, the setting conditions of the communication zone by the roadside antenna are relaxed, and the driver is troubled by the warning information for the oncoming lane. This has the effect of avoiding the situation.

According to the seventh aspect , the vehicle determines whether the danger warning information transmitted from the roadside antenna is for the own vehicle or for the oncoming lane based on the demodulated baseband signal. By the determination, the vehicle-mounted side has a simpler circuit configuration, the setting conditions of the communication zone by the roadside antenna are relaxed, and the warning information for the oncoming lane can prevent the driver from being bothered .
There is an effect similar to that of the sixth invention.

[Brief description of the drawings]

FIG. 1 shows a vehicle-mounted wireless device and road-to-vehicle communication according to the present invention.
FIG. 1 is a diagram showing a system configuration of a communication system according to a first embodiment.

FIG. 2 shows a vehicle-mounted wireless device and road-to-vehicle communication according to the present invention;
1 is a configuration diagram of an in-vehicle wireless device according to a first embodiment of a communication system .

FIG. 3 shows a vehicle-mounted wireless device and road-to-vehicle communication according to the present invention.
FIG. 4 is a waveform chart for explaining an operation of the communication system according to the first embodiment.

FIG. 4 shows a vehicle-mounted wireless device and road-to-vehicle communication according to the present invention.
FIG. 4 is an enlarged waveform diagram for explaining the operation of the communication system according to the first embodiment.

FIG. 5 shows a vehicle-mounted wireless device and road-to-vehicle communication according to the present invention;
FIG. 4 is an explanatory diagram for describing an operation of the communication system according to the first embodiment.

FIG. 6 shows a vehicle-mounted wireless device and road-to-vehicle communication according to the present invention;
FIG. 6 is an explanatory diagram for describing an operation example of the communication system according to the first embodiment.

FIG. 7 shows an in- vehicle wireless device and road-to-vehicle communication according to the present invention.
FIG. 10 is an explanatory diagram for describing a configuration and operation of a communication system according to a second embodiment.

FIG. 8 shows an in- vehicle wireless device and road-to-vehicle communication according to the present invention.
FIG. 10 is an explanatory diagram for describing an operation example of a second embodiment of the communication system .

FIG. 9 shows an in- vehicle wireless device and road-to-vehicle communication according to the present invention.
FIG. 15 is an explanatory diagram for describing another operation example of the second embodiment of the communication system ;

FIG. 10 shows a vehicle-mounted wireless device and a road-to-vehicle device according to the present invention.
FIG. 9 is a configuration diagram of a vehicle-mounted wireless device according to a third embodiment of the communication system .

FIG. 11 shows a vehicle-mounted wireless device and a road-to-vehicle device according to the present invention.
FIG. 9 is a waveform chart for explaining an operation of the communication system according to the third embodiment.

FIG. 12 shows a conventional in- vehicle wireless device and a road-to-vehicle communication system.
It is a diagram showing a system configuration systems out.

FIG. 13 shows a conventional in- vehicle wireless device and a road-to-vehicle communication system.
It is a configuration diagram of a vehicle wireless device systems out.

FIG. 14 shows a conventional in- vehicle wireless device and a road-to-vehicle communication system.
It is an explanatory diagram for explaining an operation example systems out.

[Explanation of symbols]

1 lane, 2 communication zone, 3 vehicle, 4 on-board wireless device, 5 roadside wireless device, 5a roadside antenna, 5b transmitting / receiving unit, 5c communication control unit, 6 roadside network, 7
On-board antenna, 7a On-board transmission antenna, 7b On-board reception antenna, 8 reception wave, 9 reception unit, 10 reception data signal, 11 communication control unit, 12 transmission data signal,
13 transmitting section, 14 transmitting wave, 15 second in-vehicle receiving antenna, 16 receiving wave, 17 phase comparing section, 18 phase comparing output, 19 direction determining section, 20 direction determining result, 2
1 in-vehicle bus, 22 reception unit, 23 reception data signal,
24 Obstacles.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G08G 1/00-1/16 B60K 31/00 H04B 7/26

Claims (8)

(57) [Claims] An in-vehicle wireless device that communicates with a roadside wireless device provided on a road, comprising two antennas that are spaced apart from each other and the two antennas from the roadside wireless device .
Comparing the received signal of each antenna, and a direction determining unit that identifies the traveling direction of the host vehicle based on the positional relationship between the comparison result and the roadside apparatus and the lane on the road, before
Using the difference in the propagation path length of the radio wave from the roadside wireless device
An in-vehicle wireless device for identifying a traveling direction of the vehicle on a road . 2. The antenna according to claim 1, wherein the direction determination unit includes the two antennas.
2. The phase of each received signal is compared, and the arrival direction of the received signal is determined from the comparison result.
2. The on- vehicle wireless device according to claim 1. 3. The on-vehicle wireless device according to claim 1 , wherein one of the two antennas is disposed in front of the vehicle, and the other is disposed behind the vehicle. 4. The method according to claim 1, wherein the determination result of the direction determination unit is
When the receiving side of a signal advanced from the front of the vehicle in phase of the two antennas each received signal to the appropriate notices to the driver, the received signal of each of the two antennas
4. The in -vehicle wireless device according to claim 3, further comprising a notification control unit that does not notify the driver when a signal on the side advanced in phase from behind the own vehicle is received. 5. The on-vehicle wireless device according to claim 1, wherein one of the two antennas is disposed on the left side of the vehicle, and the other is disposed on the right side of the vehicle. 6. When the roadside apparatus travels on a road disposed on the left side in the traveling direction of a lane, the reception signals of the two antennas are determined based on the determination result of the direction determination unit .
When a signal on the side where the phase is advanced from the left side of the own vehicle is received, the driver is notified to that effect and the two antennas
The side of each received signal whose phase has advanced from the right side of the vehicle
The in-vehicle wireless device according to claim 5, further comprising a notification control unit that does not notify the driver when the signal of (1) is received. 7. The antenna according to claim 6, wherein the direction determination unit includes the two antennas.
The in-vehicle wireless device according to claim 1, wherein the respective received signals are compared based on a baseband signal demodulated from each of the received signals. 8. In order to perform communication with the vehicle on the lane, car
Divided per width direction of the line interactive road by the traveling direction, and the road per traveling direction of the lane is divided into a plurality of communication sections, each said communication path, a plurality of vehicles existing independently of the number of communication sections transmitting and receiving control information to and from a plurality of roadside devices that equal existence and number of communication intervals, vehicle according to any one <br/> of claims 1 to 7 communicates with the roadside apparatus A road-to-vehicle communication system including a wireless device.