JP2002077199A - Communication method and communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely transmit data by the communication of one time without the collision of the communication among many unspecified mobile stations without the presence of a master station. SOLUTION: Absolute time information is received by a GPS receiver 16 and also absolute position information is obtained. On the basis of the obtained absolute time information and absolute position information in a frame specification allocation part 26, the frame number FN of a transmission frame Sa (the transmission frame Sa is generated in synchronism with the absolute time information) for making a transmission timing different from the other mobile station is allocated, and transmission is performed by the transmission frame Sb (the transmission frame Sb is allocated based on the absolute position information) of the different timing of allocating the frame number FN. In such a manner, even in the case that the master station is not present, the transmission time, that is the transmission timing, becomes different from each other among many unspecified mobile stations present at the positions of different absolute positions and the communication does not collide.

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 method and a communication device suitable for application to a 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 another vehicle may enter or leave the group at the next point in time.
Group composition changes from moment to 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. However, the ID is unknown for many unspecified vehicle partners and cannot be used. 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). Provided is a communication method and a communication device that can avoid or reduce the occurrence of collision of communication in mutual communication even when the number of a transceiver mounted on each vehicle is unknown or unknown. With the goal.

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. It is another object of the present invention to provide a communication method and a communication device which are excellent in real-time property.

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 method and a communication device capable of determining a position or a position of another vehicle.

[0012]

A communication method according to the present invention comprises:
In a communication method performed in each vehicle to perform communication between vehicles, a receiving step of receiving time information and position information by a receiver, and mounting the vehicle on the vehicle based on the received time information and position information. A transmission step of setting the transmission timing of the transmitter to be different from the transmission timing of another vehicle (the invention according to claim 1).

A communication device according to the present invention includes a communication transmitter and a communication receiver for performing communication between vehicles, a time position information receiver for receiving time information and position information,
Based on the time information and position information received by the time position information receiver, the transmission timing of the communication transmitter,
Transmission timing control means for setting a timing different from the transmission timing by another vehicle is provided (the invention according to claim 6).

According to the present invention, the transmission timing of the transmitter of the vehicle is set to be different from the transmission timing of another vehicle based on the time information and the position information received by the receiver. The occurrence of communication collision is prevented.

[0015] In this case, the time information and the position information are stored in the GPS.
It can be received by the receiver, the position of the own vehicle can be determined, and the position of the other vehicle can be obtained by communication as needed (the invention according to claims 2 and 7).

If the position information is unnecessary, the transmission timing of the transmitter mounted on the vehicle differs from the transmission timing of another vehicle based on the received time information and the identification information of the vehicle. By setting the timing, it is possible to prevent the occurrence of communication collision in the mutual communication (the inventions according to claims 3 and 8). As the identification information of the vehicle, all or a part of a chassis number or a license plate number can be used.

Incidentally, a random number can be used as the identification information of the vehicle (the invention according to claims 4 and 9).

As the time information, time information per second in Coordinated Universal Time or time information generated every second, received by a GPS receiver, or time information per second received by a radio clock is used. (Claims 5 and 1)
0). Thus, real-time communication can be ensured.

The communication frequency used for the vehicle communication device of the present invention may be, for example, 3
It is preferable to use a millimeter wave of about 0 to 300 GHz (wavelength 1 cm to 1 mm). Millimeter waves are straight,
Also, it is resistant to weather conditions such as rain and snow,
It is suitable for communication on the ground surface, for example, within about ± 200 m.

[0020]

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 apparatus 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 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.
GPS receiver (time position information receiver) 1 to which 4 is connected
6 and the output of the GPS receiver 16 is
And to the position calculation unit 20.

A radio timepiece 22 is connected to the time determining unit 18 as necessary, and the output of the time determining unit 18 is supplied to a transmission frame generating unit 24.

The output of the transmission frame Sa, which is the output of the transmission frame generator 24, and the output of the position calculator 20 are supplied to a frame specific allocator (transmission timing control means) 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, the vehicle ID input unit 30
A number such as the last two digits in the number of the host vehicle 100 is specified and input by the switch 32. The setting operation for the switch 32 can be performed using a display on a monitor (not shown). As the switch 32, a hardware switch such as a dip switch can be used 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 following 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 it has straightness,
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 (a 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 receivers 52 and 56 is received by a data processor (also referred to as a received data processor) 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.

The above-mentioned GPS receiver 16 includes a GPS
DGPS receivers that utilize signals from satellites and signals from terrestrial base stations whose location is accurately known can also be used.

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 respectively
The antennas 48 and 54 of the rear transmitting unit 46 and the rear receiving unit 56 are provided on 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 further detail.

The GPS receiver 16 receives spread spectrum modulated satellite signals from a plurality of GPS satellites via the antenna 14, demodulates navigation data necessary for positioning calculation from the satellite signals, and performs positioning based on the demodulated navigation data. The calculation is performed, and the position information (latitude and longitude information) of the vehicle 100 on which the communication device 10 is mounted is output to the position calculation unit 20 and the time information at the time of reception is output to the time determination unit 18.

In this case, the time information at the time of reception is the absolute time common to the vehicles including the vehicle 100 and received by the surrounding communication target vehicles including the vehicle 100.

Here, the time information is defined as Coordinated Universal Time UTC
(Coordinated universal time) or PPS (pulse per sec) which is time information generated every second.
Note that, as the time information, time information obtained by demodulating the long-wave standard radio wave into which the time code received by the radio clock 22 is inserted can be used. Either one of the time information from the GPS receiver 16 and the time information from the radio clock 22 may be used.

The time determining section 18 determines every 0 seconds of the time information, and sends out the 0 second information to the transmission frame generating section 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), in other words, every one second shown in FIG. 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 vehicle 100, in other words, a frame number FN having a different value for each vehicle. I do. More specifically, for example, only the value portion of the latitude and longitude of the position information of 0.1 minutes or less is extracted, and the extracted value is 0.000 minutes or more and 0.005 minutes or more.
If the time is less than 1 minute, the value is 1; if it is 0.005 minutes or more and less than 0.01 minute, the value is 2;
, One row and one column in the form of a matrix (when latitude and longitude are 0.000 minutes or more and less than 0.005 minutes, respectively)
Is the value 1, 1 row, 2 columns (similarly, latitude 0.000 minutes or more 0.0
A value of less than 05 minutes, a longitude of 0.005 minutes or more and less than 0.01 minutes is a value of 2, and 20 rows and 20 columns (latitude and longitude of 0.09 each).
(5 or more and less than 0.01 minute) is assigned a frame number FN with a value of 400. On the surface of the earth, 0.1 minute corresponds to about 185 m.

Next, the frame specific allocating section 26 synchronizes with the rise or fall of the transmission frame Sa generated by the transmission frame generation section 24 every 0 seconds, based on the frame number FN assigned by the position calculation section 20. Figure 1
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 includes the 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, It is transmitted as a millimeter wave radio signal having vehicle information of another vehicle, and a transmission frame Sb from the other vehicle is received by the receiving unit 5.
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 the vehicle 100 is identified by the 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, a single collision can be performed without communication collision between an unspecified number of vehicles capable of receiving GPS satellite signals. Reliable data transmission can be performed by communication.

In this embodiment, it is mainly described that reliable communication can be established for communication used for traveling control of the mobile station. However, when the space between vehicles 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.

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

When follow-up running is unnecessary, for example, when the present invention is applied to a general business radio system such as a so-called taxi, the specific information of the frame number FN is replaced with the position information from the GPS receiver 16. The random number generated by the random number generation unit 28 or the vehicle ID input unit 3
Using the vehicle ID supplied from 0, the frame number FN of each communication device as a mobile station can be generated by a random number. In this case, 150 millimeters are used instead of millimeter waves.
It is preferable to use radio waves in the MHz or 400 MHz band.

Therefore, the GPS receiver 16, the radio clock 22, the random number generator 28, and the vehicle ID input unit 30
They can be used in an appropriate combination according to the purpose of use, cost and the like.

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0056]

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. Therefore, when vehicles equipped with transceivers communicate with each other as an unspecified number of wireless stations (fixed or mobile stations), the number of transceivers installed in each vehicle is unknown or unknown. Even so, it is possible to avoid or reduce the occurrence of communication collision in inter-communication.

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. As a result, it is possible to avoid or reduce the occurrence of communication collision in intercommunication.

By using, as time information, time information per second in Coordinated Universal Time or time information generated every second, received by a GPS receiver, or time information per second received by a radio clock, A communication system excellent in real-time property can be established.

The position of the own vehicle or the position of another vehicle can be determined by receiving the position information from the GPS receiver or the position information from the roadside device.

[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]

DESCRIPTION OF SYMBOLS 10 ... Communication apparatus 12 ... Automatic tracking control part 16 ... GPS receiver 18 ... Time determination part 20 ... Position calculation part 24 ... Transmission frame generation part 26 ... Frame specific allocation part 28 ... Random number generation part 30 ... Vehicle ID input part 34 ... Data processing units 42, 46 ... Transmission units 52, 56 ... Reception unit 55 ... Data processing unit 100 ... Vehicle

Claims (10)

[Claims] 1. A communication method carried out in each vehicle for performing communication between vehicles, comprising: a receiving step of receiving time information and position information by a receiver; and A transmission step of setting a transmission timing of a transmitter mounted on the vehicle to be different from a transmission timing of another vehicle. 2. The communication method according to claim 1, wherein in the receiving step of receiving the time information and the position information by a receiver, the GPS receiver receives the time information and the position information. Method. 3. A communication method carried out in each vehicle for performing communication between vehicles, comprising: a receiving step of receiving time information by a receiver; and a receiving step based on the received time information and identification information of the vehicle. A transmission step of setting a transmission timing of a transmitter mounted on a vehicle to a timing different from a transmission timing of another vehicle. 4. A communication method carried out in each vehicle for performing communication between vehicles, comprising: a receiving step of receiving time information by a receiver; and a receiving step, based on the received time information and a random number generated in the vehicle. A transmission step of setting a transmission timing of a transmitter mounted on the vehicle to be different from a transmission timing of another vehicle. 5. The communication method according to claim 1, wherein said time information is time information for each second in Coordinated Universal Time or a time for each second received by a GPS receiver. A communication method characterized by using time information generated or time information per second received by a radio clock. 6. A communication transmitter and a communication receiver for performing communication between vehicles, a time position information receiver for receiving time information and position information, and a time received by the time position information receiver. Based on the information and the position information, the transmission timing of the communication transmitter,
A transmission timing control unit that sets a timing different from a transmission timing by another vehicle. 7. The communication device according to claim 6, wherein the time position information receiver is a GPS receiver. 8. A communication transmitter and a communication receiver for performing communication between vehicles, a time information receiver for receiving time information, a time information received by the time information receiver, and an identification of the vehicle. A transmission timing control unit that sets a transmission timing of the communication transmitter to a timing different from a transmission timing of another vehicle based on the information. 9. A communication transmitter and a communication receiver for performing communication between vehicles, a time information receiver for receiving time information, a random number generator for generating a random number, and the time information receiver. Based on the received time information and the random number generated by the random number generator, a transmission timing control unit that sets the transmission timing of the transmitter mounted on the vehicle to a timing different from the transmission timing by another vehicle; A communication device comprising: 10. The communication device according to claim 6, wherein the time information is time information per second in Coordinated Universal Time or received per second received by a GPS receiver. A communication device using time information generated or time information per second received by a radio clock.