JP2002077037A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system where many unspecified mobile stations can surely transmit data to each other with one communication without collision of communication in the absence of a master station. SOLUTION: A road side receiver 16 receives absolute time information from a road side transmitter 4 and obtains absolute position information. A frame assignment section 26 assigns a frame number FN of a transmission frame Sa (the transmission frame Sa is generated synchronously with the absolute time information) to frames to differentiate transmission timing of the frames from those by other mobile stations on the basis of the obtained absolute time information and absolute position information. The mobile station transmits a transmission frame Sb (the transmission frame Sb is assigned on the basis of the absolute position information) with the frame number FN assigned thereto and having different timings. Thus, even in the case of absence of a master station, many unspecified mobile stations resident at positions whose absolute positions differ from each other have different transmission times, that is, different transmission timings with each other so as to avoid communication collision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a vehicle-to-vehicle (vehicle-to-vehicle) system in which two or more vehicles equipped with a transceiver communicate with each other as an unspecified number of radio stations (fixed or mobile stations). The present invention relates to a communication device suitable for application to communication technology.

[0002]

2. Description of the Related Art In a conventional communication system for a vehicle, a radio station is generally specified. Therefore, although there is a distinction between individual communication, group communication, simultaneous communication, etc., by control from the master station (control station, centralized base station, etc.),
Transmission timing or slot allocation of a transmission frame is performed, and mutual communication for avoiding collision is performed.

For example, in order to wirelessly transmit data such as vehicle information (for example, a driving operation amount such as a steering amount and a throttle opening) between running or stopped vehicles, a communication target vehicle is known in advance. In such a case, for example, in the case of so-called convoy running for collective transportation by a long-distance trailer, a method is employed in which all vehicles are grouped and communication between the vehicles is controlled using the leading vehicle as a control station.

On the other hand, a communication system having no master station, that is, a communication call between an unspecified number of wireless stations is premised on communication with a partner whose transceiver number or the like is known. In this case, it is possible to output a transmission request from the own vehicle, determine the other party based on the identification number of another vehicle, so-called ID, or the like that has responded to the request, and establish a communication path.

[0005]

Recently, in order to rationalize transportation by lorry or reduce traffic accidents,
Research and development of an automatic follow-up traveling system for a vehicle is being advanced. In order to perform the automatic following, in particular, vehicle information (such as the above-described steering amount and throttle opening degree, brake depression amount, etc.) and position information (latitude and longitude) of the preceding vehicle and the following vehicle around the own vehicle immediately before and after the vehicle. , Etc., or relative position information centered on itself) must be repeatedly transmitted at high speed and in real time, and skipping information on any vehicle is not preferred.

However, in general traveling, grouping is possible at a certain point in time, but at the next point in time, another vehicle may enter or leave the group, so that the group configuration changes every moment. For this reason, there is a problem that it is not possible to determine a vehicle that is a control station (base station) that becomes the center of the group and that can control the vehicles in the group.

Although it is possible to prevent communication collision by adopting an MCA (multi channel access) method and substantially increasing the number of usable channels, this is a case where a communication partner is known. The ID cannot be used by an unspecified number of vehicle partners because the ID is unknown.
Also, the position of the communication vehicle cannot be determined.

As described above, when data for vehicle control or vehicle control assistance is to be communicated by vehicle-to-vehicle communication (also referred to as vehicle-to-vehicle communication), it is more reliable at a time when a collision does not occur. And real-time communication is required.

The present invention has been made in view of such problems, and is intended for use when vehicles equipped with transceivers communicate with each other as an unspecified number of wireless stations (fixed stations or mobile stations). It is an object of the present invention to provide a communication device capable of avoiding or reducing the occurrence of communication collision in mutual communication even when the number of a transceiver mounted on each vehicle is unknown or unknown. I do.

Further, the present invention makes it possible to avoid or reduce the occurrence of communication collision in intercommunication even when a control station (master station) does not exist or is not grouped. Another object of the present invention is to provide a communication device which is excellent in real-time performance.

Further, the present invention avoids or reduces the occurrence of communication collisions in inter-communications even when a control station (master station) does not exist or is not grouped, and also controls the own vehicle. It is an object of the present invention to provide a communication device capable of determining a position or a position of another vehicle.

[0012]

A communication device according to the present invention comprises:
A communication transmitter and a communication receiver for performing communication between vehicles; a roadside information receiver for receiving time information and roadside device position information transmitted from a roadside device disposed on the road; and the roadside information. The roadside device position information received by the receiver is used as an initial setting position, the self-contained navigation device that calculates own vehicle position information, and the time information received by the roadside information receiver are synchronized with the timing every second, and the own vehicle A transmission timing control means for allocating a transmission frame of the own vehicle from the position information and performing transmission from the communication transmitter in the allocated transmission frame (claim 1).
Described invention).

According to the present invention, the transmission frame is allocated in synchronization with the timing of each second of the time information received by the roadside information receiver and based on the own vehicle position information calculated from the received roadside device position information. Since the vehicle-to-vehicle communication is performed in the transmission frame, reliable data transmission can be performed by one communication without communication collision between an unspecified number of communication devices.

When the roadside device identification information is transmitted instead of the roadside device position information transmitted from the roadside device,
The vehicle position information may be calculated by the vehicle position calculation means from the roadside device identification information (the invention according to claim 2).

It is preferable that the roadside devices are arranged at predetermined intervals along the road. This is because the self-contained navigation can be corrected at every predetermined interval, and the time information every second can be reset (the invention according to claim 3).

In the present invention, it is preferable to use, for example, a millimeter wave having a frequency of about 30 to 300 GHz (wavelength: 1 cm to 1 mm) as a communication frequency used for the vehicle communication device for automatic following running. . Millimeter waves have straightness and are resistant to weather conditions such as rain and snow, so they are suitable for communication on the ground surface, for example, within about ± 200 m.

[0017]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a communication device 10 to which an embodiment of the present invention is applied.

FIG. 2 shows a radio station (mobile station or fixed station).
(Also referred to as own vehicle or own vehicle) 100
Is schematically shown. In this case, roadside transmitters 4 controlled by a roadside system 2 having a computer are arranged at regular intervals on the road on which the vehicle 100 runs.

In FIG. 1, a portion surrounded by a dotted line indicates an automatic following control unit 12 for allowing the vehicle 100 to travel following the preceding vehicle.

The communication device 10 shown in FIG. 1 receives an electric wave transmitted from the roadside transmitter 4 via the antenna 6 (this electric wave is preferably a microwave including a millimeter wave having a narrow directivity). The roadside receiver (roadside information receiver) 16 is connected to the roadside receiver 14. The output of the roadside receiver 16 is supplied to a time determination unit 18 and to a position calculation unit 20.

The output of the time determination unit 18 is supplied to a transmission frame generation unit 24. The output of the position calculating unit 20 is supplied to the self-contained navigation device 11 and also to a frame specific allocating unit (transmission timing control unit) 26.

The self-contained navigation device 11 includes a gyro device, calculates own vehicle position information using the output of the position calculating unit 20 as an initial setting position, and supplies the information to the frame specifying allocating unit 26 via the position calculating unit 20.

The transmission frame Sa output from the transmission frame generator 24 and the output from the position calculator 20 are supplied to a frame specific allocator 26. In addition to the output of the position calculating section 20, the output of a random number generating section (random number generator) 28 and the output of a vehicle ID input section 30 which will be described later as other embodiments are also supplied to the frame specifying allocating section 26. . In this case, numbers such as the last two digits in the number of the vehicle 100 are specified and input to the vehicle ID input unit 30 by the switch 32. The setting operation for the switch 32 can be performed using a display on a monitor (not shown). The switch 32 may be a hardware switch, such as a dip switch, instead of a software switch.

The frame specific allocating unit 26 automatically calculates the input information based on an algorithm described later.
Transmission frame S supplied from transmission frame generation unit 24
The frame number FN of the own vehicle 100 is assigned to a. Transmission frame S to which frame number FN is assigned
b denotes a data processing unit (also referred to as a transmission data processing unit) 34 of a transmission system, and a transmission unit for a vehicle ahead (a front transmission unit).
42 and a receiving section (front receiving section) 52, and a transmitting section (rear transmitting section) 46 and a receiving section (rear receiving section) 56 for a vehicle behind.

Here, the front transmitting unit 42 and the rear transmitting unit 4
6, and the front receiving unit 52 and the rear receiving unit 56 respectively constitute a communication transmitter and a communication receiver for performing communication between vehicles.

The sensor 3 constituting the automatic follow-up control unit 12
6. For example, the vehicle information such as a vehicle speed sensor, a yaw rate sensor, a brake sensor, an inter-vehicle distance sensor, a road surface state detection sensor, and a sensor signal from an obstacle detection sensor is transmitted to the transmission data processing unit 34 and the vehicle through the vehicle information collection unit 40. It is sent to the control unit 58.

The transmission data processing section 34 has a frame number F
The own vehicle information is transmitted to the front transmission unit 42 and the rear transmission unit 46 during the transmission frame Sb to which N is assigned.

The front transmitting unit 42 and the rear transmitting unit 46
During the transmission frame Sb, the vehicle information of the own vehicle 100 is transmitted as a millimeter wave radio signal to the vehicle ahead via the antenna 44 and is transmitted as a millimeter wave radio signal to the vehicle behind via the antenna 48.

The reason for using the millimeter wave {30 to 300 GHz (wavelength 1 cm to 1 mm)} is that there is a straight line,
In addition, since it is resistant to weather conditions such as rain and snow,
This is because it is suitable for communication within about ± 200 m on the ground.

On the other hand, each transmission frame Sb transmitted from the preceding and following vehicles (transmission frame to which a frame number FN different from the transmission frame Sb of the own vehicle 100 is assigned)
The millimeter wave radio signal containing the vehicle information sent during
The signal is received via the antenna 50 and the front receiving unit 52, and is received via the antenna 54 and the rear receiving unit 56.

The data received from the receiving units 52 and 56 is received by a data processing unit (also referred to as a reception data processing unit) 55 of the receiving system.
Sent to The reception data processing unit 55 sends, for example, vehicle information (other vehicle information) of the preceding vehicle in position to the vehicle control unit 58. The vehicle control unit 58 drives the vehicle drive unit 60 including the steering, the engine, the brake, and the like of the own vehicle 100 based on the vehicle information of the immediately preceding vehicle, and sends an alarm signal to the alarm display unit 62 as necessary.
The vehicle control unit 58 can also perform feedback control of the vehicle drive unit 60 based on the own vehicle information transmitted from the vehicle information collection unit 40. If necessary, an alarm is displayed on the alarm display unit 62. It has the function of displaying.

Each component shown in FIG. 1 is controlled by a control unit 66 including a CPU.

As shown in FIG. 2, the antennas 44 and 50 of the front transmitting section 42 and the front receiving section 52 are connected to the vehicle 10 respectively.
No. 0 is attached to the front bumper, and the antennas 48 and 54 of the rear transmitting unit 46 and the rear receiving unit 56 are attached to the rear bumper.

The communication device 10 according to this embodiment is basically configured and operated as described above, and the operation will be described in detail below.

The roadside transmitter 4 whose transmission content is determined by the roadside system 2 transmits the time information and the latitude and longitude position information of the position where the roadside transmitter 4 is installed to the antenna 6.
Is transmitted as a radio wave through.

Only when the vehicle 100 reaches a position substantially immediately below the position where the roadside transmitter 4 is installed, the vehicle 100
The roadside receiver 16 mounted on the 00 can receive the time information and the roadside apparatus position information via the antenna 14.

The roadside receiver 16 outputs the received position information (latitude and longitude information) to the position calculation unit 20 and outputs the received time information to the time determination unit 18.

In this case, the time information at the time of reception is received at different times also in the surrounding vehicles to be communicated including the vehicle 100, but becomes an absolute time common to these vehicles.

The time determining unit 18 determines every 0 seconds of the time information, and sends out the 0 second information to the transmission frame generating unit 24. The 0-second information is also common information between the communication target vehicles including the vehicle 100.

The transmission frame generator 24 receives the 0-second information and synchronizes with the 0-second information (time information). A transmission frame Sa as a time reference signal (0 second information signal) that rises or falls is generated.

The position calculating section 20 calculates, based on the position information (latitude / longitude information), identification information (vehicle identification information) unique to the own vehicle, in other words, a frame number FN having a different value for each vehicle. . More specifically, for example, only the value part of the latitude and longitude of the position information, for example, 0.1 minutes or less, is extracted. If the extracted value is 0.000 minutes or more and less than 0.005 minutes, the values 1, 0 are set. A value of 2 for 0.005 minutes or more and less than 0.01 minutes, a value of 20 for 0.095 minutes or more and less than 0.01 minutes, and one row and one column (latitude and longitude of 0.000 minutes or more and 0 for each Value less than 0.005 minutes), value 1, 1 row, 2 columns (similarly, latitude 0.000 minutes or more and 0.005
Minutes, longitude 0.005 minutes or more and less than 0.01 minutes) is a value 2, and 20 rows and 20 columns (latitude / longitude 0.095 each)
(Less than 0.01 minute) as the value 400 and the frame number F
N is given. On the surface of the earth, 0.1 minute is about 1 minute.
It corresponds to 85m.

If the position information transmitted from the roadside transmitter 4 is not the latitude / longitude information but the identification code (roadside device identification information) of the roadside transmitter 4, the position calculator 20
, A correspondence table between the identification codes and the latitude and longitude is stored, and the own vehicle position information can be calculated with reference to the correspondence table. In this sense, the position calculation unit 20 also functions as a vehicle position information calculation unit.

Next, the frame specific allocating unit 26 synchronizes with the rising or falling edge of the transmission frame Sa generated by the transmission frame generating unit 24 every 0 seconds, based on the frame number FN given by the position calculating unit 20. , FIG.
M transmission frames Sb divided by m (here, m = 400) shown in FIG. 3 (b) ｃ (c) in FIG. 3 to (f) in FIG.
The transmission frames Sb1, Sb2, Sb3,.
m｝ is generated and sent to the data processing unit 34, the transmitting units 42 and 46, and the receiving units 52 and 56. Here, the time of each frame of the m transmission frames Sb is allocated to the same time.

At this time, the data processing unit 34 stores the own vehicle 1 such as the steering angle and the throttle opening collected by the sensor 36.
00 is supplied, the vehicle information is edited, and the transmission frame Sb assigned to the vehicle 100 is
In the meantime, the transmitters 42 and 46 transmit millimeter-wave radio signals to the preceding and following vehicles (not limited to two). That is, the transmission units 42 and 46 transmit at the timing corresponding to the frame number FN of the vehicle 100.

On the other hand, from another vehicle operating in the same configuration as that of the own vehicle 100 (the configuration shown in FIGS. 1 and 2), in synchronization with the transmission frame Sb of the frame number FN assigned to the other vehicle, Transmitted as a millimeter wave radio signal having vehicle information of another vehicle, and a transmission frame Sb from the other vehicle
2, 56 and demodulated by the data processing unit 55.
Sent to As shown in FIG. 3 (f), the receiving operation is continuously performed from the time point t0 at which the transmission frame Sa occurs every 0 seconds to the time point t1 at which all the transmission frames Sb disappear.

The data processing unit 55 calculates the current geographical position of the vehicle existing near the own vehicle 100 from the position on the time axis of the demodulated vehicle information of the other vehicle and the transmission frame Sb related to the assigned frame number FN. All positions (latitude and longitude) can be grasped. To elaborate, for simplicity,
When the transmission frame Sb2 is assigned with the frame number FN of the own vehicle 100 being FN = 2 as shown in FIG. 3D, the transmission data of the frame number FN = 1 is set at the time (time) one frame before that. (Transmission frame Sb1) is obtained, and the frame number F
N = 3 transmission data (transmission frame Sb3) is obtained. When the transmission data (transmission frame Sb3) is obtained, the position of the succeeding vehicle can be specified from the latitude and longitude data and the like in the transmission frame Sb3, and the position of the preceding vehicle moving by the time two frames before is determined by the vehicle speed and the like. Can be used for the estimation calculation.

When the received data is obtained, for example, while the vehicle is moving forward, the vehicle existing immediately before own vehicle 100 is identified by frame number F.
N based on the vehicle information of the preceding vehicle specified from the transmission frame Sb related to the N
The drive control of the vehicle driving unit 60 of 0 is performed to perform an automatic following operation. In addition, an alarm is displayed on the alarm display unit 62 as needed.

As described above, according to the above-described embodiment,
A transmission frame Sb (Sb) having a frame number FN at a different timing from the transmission frame Sa generated every 0 seconds
= Sb1, Sb2, Sb3,... Sbm). Each of the transmission frames Sb is set to 0
Since the timing is changed based on the absolute position information at the time of seconds and the absolute time information is used as a trigger, the time information and the position information from the roadside transmitter 4 can be received between an unspecified number of vehicles. Reliable data transmission can be performed by one communication without communication collision.

In this embodiment, it is mainly assumed that reliable communication can be established for communication used for traveling control of a mobile station. However, when communication is blocked due to traffic congestion or the like, communication is performed. Since data is not used for traveling control, there is no problem even if there is a communication collision.

It is also conceivable that the errors occurring in the receiving unit, the arithmetic unit and the like of each communication device 10 are different for each device. However, the maximum value of these errors can be assumed on each device, and this value is the transmission time. Since this can be made so small that it can be disregarded as compared with the above, it is possible to solve this problem by providing an operation in consideration of the maximum value of the error in the apparatus.

Further, the roadside system 2 can be newly installed.
l collection system: non-stop toll collection system, VICS (vehicle information and communicat)
This function can be realized by adding this function to other existing wireless equipment such as a roadside device, a beacon, and the like related to an ion system (road traffic information communication system).

As another embodiment of the present invention,
When follow-up traveling is unnecessary, for example, when applied to a general business radio system such as a so-called taxi,
Regarding the specific assignment of the frame number FN, the roadside transmitter 4
Instead of the position information from the vehicle, the random number generated by the random number generation unit 28 or the vehicle I supplied from the vehicle ID input unit 30
Using D, the frame number FN of each communication device as a mobile station can be generated by a random number. In this case, it is not a millimeter wave but a 150 MHz band or a 400 MHz band.
It is preferable to use radio waves in the MHz band.

Further, the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

[0055]

As described above, according to the present invention, the time information is received, the position information or the identification information of the vehicle is obtained, and the transmission timing is made different from that of another vehicle based on the information. An unspecified number of wireless stations (fixed or mobile stations)
When performing mutual communication, it is possible to avoid or reduce the occurrence of communication collision in mutual communication, even if the number of the transceiver mounted on each vehicle is unknown or unknown.

Further, according to the present invention, even when a control station (master station) does not exist or is not grouped, transmission is performed at a different timing based on time information and position information or vehicle identification information. By doing so, it is possible to avoid or reduce the occurrence of communication collision in intercommunication.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a communication device to which an embodiment of the present invention has been applied.

FIG. 2 is a schematic diagram of a vehicle equipped with the communication device of FIG. 1;

FIG. 3 is a time chart for explaining the operation of the example of FIG. 1;

[Explanation of symbols]

2 roadside system 4 roadside transmitter 10 communication device 11 self-contained navigation device 12 automatic tracking control unit 18 time determination unit 20 position calculation unit 24 transmission frame generation unit 26 frame specific allocation unit 28 random number generation Unit 30 Vehicle ID input unit 34 Data processing unit 42, 46 Transmitting unit 52, 56 Receiving unit 55 Data processing unit 100 Vehicle

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiro Watanabe 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture F-term in Matsushita Communication Industrial Co., Ltd. 5K028 AA14 BB04 CC05 HH02 MM08 MM16 NN43 5K047 AA11 BB01 JJ08 MM11 5K067 AA21 BB26 DD20 DD30 EE02 EE14 EE22 EE33 EE34 FF03 FF06

Claims (3)

[Claims] A communication transmitter and a communication receiver for performing communication between vehicles, and a roadside information receiver for receiving time information and roadside device position information transmitted from a roadside device disposed on a road. A roadside device position information received by the roadside information receiver as an initial setting position, and a self-contained navigation device for calculating own vehicle position information; and synchronizing with a timing every second of the time information received by the roadside information receiver. And a transmission timing control means for allocating a transmission frame of the vehicle from the vehicle position information and performing transmission from the communication transmitter using the allocated transmission frame. 2. A communication transmitter and a communication receiver for performing communication between vehicles, and a roadside information receiver for receiving time information and roadside device identification information transmitted from a roadside device disposed on a road. Own vehicle position information calculating means for calculating own vehicle position information from the roadside device identification information received by the roadside information receiver; and initial vehicle position information calculated by the own vehicle position information calculating means. And a self-contained navigation device that sequentially calculates the position of the own vehicle, synchronizes with the timing of each second of the time information received by the roadside information receiver, and allocates a transmission frame of the own vehicle from the own vehicle position information, A communication timing control unit for performing transmission from the communication transmitter in the transmitted frame. 3. The communication device according to claim 1, wherein the roadside devices are arranged at predetermined intervals along the road.