JPH0935185A - Vehicle communication system and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to transmit/receive much information between a road and a vehicle and between vehicles without preparing communication constitution in each information sort and to attain also group traveling control and automatic traveling control. SOLUTION: A 1st transceiver 1 for directing a driving direction and a 2nd transceiver 2 for directing the reverse direction against the driving direction are loaded on a vehicle and a transceiver 3 connected to a road side communication network is arranged on the road side. Each of these transceivers is provided with a data packet transmitting/receiving means (1) and a relative position detecting means (2) for measuring a difference between the transmitting time of a signal for carrying an originating source data packet from the transceiver itself and the receiving time of a return signal for carrying a return data packet from the opposite transceiver in response to the transmitted data packet and the incident angle of the signal from the opposite transceiver and obtaining relative position information between its own transceiver and the opposite transceiver based upon the measured values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle communication system and a vehicle capable of constructing the vehicle communication system, and more particularly, not only between a vehicle and a roadside (hereinafter referred to as road-vehicle) but also between vehicles. It enables communication by the same communication system element.

[0002]

2. Description of the Related Art Conventionally, there is a road-to-vehicle information system described in Document 1 as a device for providing a road-to-vehicle communication path between a vehicle (automobile, motorcycle, etc.) and a roadside communication network. This is to form a wireless area using a spot-like radio wave or light wave of about 60 m between a road station (beacon) and a vehicle which are arranged at intervals of several 100 m to several km on the road, and intermittently between the road vehicles. A communication path is provided, and communication is intermittently performed every time a vehicle passes through the wireless area.

Reference 1 “Nori Nakagata, Yutaka Yamada,“ Vehicle Information Experiment System ”, Oki R & D Vol.57, No.3, pp.4
5-48, July 1990] Further, as another communication system, a method of laying a leaky coaxial cable on the roadside and providing a continuous communication path between the leaky coaxial cable and a vehicle has been proposed.

[0004]

By the way, on a highway or the like, the traveling of one group of vehicles is controlled from the roadside or another vehicle (hereinafter referred to as group traveling), and the traveling of one vehicle is automatically controlled from the roadside. If this is possible (hereinafter referred to as "automatic driving"), safety can be improved and smooth driving can be realized.
In addition, if traveling environment information, a danger warning, etc. can be provided to a certain vehicle from the roadside or another vehicle, smooth traveling can be realized and safety can be improved. Therefore, in the future, the number of types of information transmitted / received by one vehicle, including telephone information, will considerably increase, and it is desired to realize an information communication base commonly used for such many types of information. In other words, it is not preferable to provide the communication device for each information type in the vehicle or the like because the communication resources are often duplicated.

The above-mentioned former communication system is not suitable for automatic traveling or group traveling because the road-to-vehicle communication is intermittent, the position information of the vehicle is not accurate enough, and the inter-vehicle communication cannot be supported. It cannot be applied and cannot be applied as a system that builds an information and communication infrastructure commonly used for many types of information.

In the latter communication system, the position information of the vehicle cannot be obtained. Therefore, it cannot be used for automatic traveling or group traveling, and an information communication base commonly used for many information types is constructed. It cannot be applied as a system.

[0007]

According to a first aspect of the present invention, there is provided a vehicle communication system between vehicles traveling on a road, and
A wireless communication path is provided between a vehicle and a roadside communication network, and is characterized by the following points.

A vehicle is equipped with a first transceiver for directing the traveling direction and a second transceiver for directing the opposite traveling direction, and is connected to a roadside communication network at predetermined intervals on the roadside. A transmitter / receiver is installed. Then, each type of transmitter / receiver has (1) means for transmitting / receiving data packet, (2) transmission time of signal carrying data packet of its own source, and reply data packet for the data packet by partner transceiver Relative position to obtain the relative position information between the self-transceiver and other transceivers based on the difference between the reception time of the reply signal And a detection means.

A vehicle according to a second aspect of the present invention is a vehicle capable of constructing a vehicle communication system that provides a wireless communication path between vehicles running on a road and between a vehicle and a roadside communication network. , Is characterized by the following points.

A first transceiver for directing the traveling direction and a second transceiver for directing the opposite direction to the traveling direction are mounted. Then, each type of transmitter / receiver has (1) means for transmitting / receiving data packet, (2) transmission time of signal carrying data packet of its own source, and reply data packet for the data packet by partner transceiver Relative position to obtain the relative position information between the self-transceiver and other transceivers based on the difference between the reception time of the reply signal And a detection means.

[0011]

According to the first and second aspects of the present invention, various kinds of information are transmitted and received by exchanging signals in which data packets are modulated between the roadside transceiver and the transceiver mounted on the vehicle. In addition, the relative position information can be obtained from each other based on the round-trip time and the direction of arrival of the modulated signal, and the data packet modulated signals can be exchanged between the transmitters and receivers mounted on different vehicles. As a result, various kinds of information can be transmitted and received, and relative position information can be obtained from each other depending on the round-trip time and arrival direction of the modulated signal.

As a result, a large amount of data can be exchanged between road vehicles and between vehicles without providing a communication structure for each information type, and relative position information obtained by using such a common communication structure is used. Group traveling control and automatic traveling control can also be realized.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle communication system and a vehicle according to the present invention will be described in detail below with reference to the drawings.

(A-1) Configuration of Embodiment FIG. 1 is a bird's-eye view of a road showing a schematic configuration of a vehicle communication system according to this embodiment, showing a one-way road having two lanes.

In FIG. 1, a front transmitter / receiver 1 and a rear transmitter / receiver 2 having detailed configurations shown in FIG. 2 to be described later are attached to a front part and a rear part of the vehicle, respectively. On the other hand, a roadside transceiver 3 having a detailed configuration shown in FIG. 3 which will be described later is attached to the columns installed on the roadside at substantially constant intervals. The pillar on which the roadside transceiver 3 is installed may be dedicated to this communication system, or may be an existing pillar with an illumination lamp or the like attached thereto.

The directivities of the antennas of the front transceiver 1 and the rear transceiver 2 provided on the vehicle are respectively forward and backward of the vehicle, and the preceding lanes travel in the same lane or adjacent lanes in the same direction. It is selected to have a divergence angle enough to form a two-way direct communication line 4 by radio waves between the vehicle and the following vehicle. On the other hand, the directivity of the antenna of the roadside transceiver 3 is directed in the direction opposite to the traveling direction of the vehicle, and moreover, in both directions by radio waves between the roadside transceiver 3 and the front transceiver 1 of each traveling vehicle. The divergence angle is selected so that the direct communication line 5 can be formed.

FIG. 2 is a block diagram showing an in-vehicle communication device for constructing the above-described vehicle communication system.

In FIG. 2, the vehicle-mounted communication device includes a communication controller 6 and an input / output device 7 in addition to the front transceiver 1 and the rear transceiver 2 described above.

The input / output device 7 is an input / output interface for connecting various devices using the on-vehicle communication device (hereinafter, referred to as communication utilizing device) to the on-vehicle communication device, specifically, the communication controller 6. is there. Such various types of communication utilization devices include communication terminal devices (for example, telephone terminals and facsimile terminals) and information terminal devices (for example, portable personal computers) used for general information communication, as well as travel controllers and A device used for running or driving a vehicle, such as an alarm device or a data encoder that collects and codes state variables of the vehicle, is applicable.

The communication controller 6 directly controls the front transmitter / receiver 1 and the rear transmitter / receiver 2 to communicate with the rear transmitter / receiver 2 and the roadside transmitter / receiver 3 of the preceding vehicle on the front side and the rear side. It controls communication with the front transceiver 1 of the following vehicle on the side. That is, the communication controller 6 sends the data supplied from the communication using device (not shown) via the input / output device 7.
The front transceiver 1 and the rear transceiver 2 are controlled to send to the rear transceiver 2 of the preceding vehicle on the front side, the roadside transceiver 3 and the front transceiver 1 of the following vehicle, and the front transceiver 1 and Control operation is performed such that the received data from the rear transceiver 2 is output to a communication utilizing device (not shown) via the input / output device 7. Further, various data packets described later are transmitted and received according to the communication sequence at that stage. Further, the relative position information with respect to the preceding vehicle, the following vehicle, and the roadside device is obtained.

The front transmitter / receiver 1 and the rear transmitter / receiver 2 have almost the same structure. The transmitters 11 and 21, the transmitting antennas 12 and 22, whose detailed structure is shown in FIG. 4 described later, and the detailed structure shown in FIG. The receiving antennas 13 and 23, the receivers 14 and 24 whose detailed configuration is shown in FIG. 7, which will be described later, the timers 15 and 25, and the angle measuring devices 16 and 26 whose detailed configuration is shown in FIG.

The difference between the front transceiver 1 and the rear transceiver 2 is that the carrier frequency from the former transmitter 11 is f1.
In contrast, the carrier frequency from the latter transmitter 21 is f2, and the carrier frequency receivable by the former receiver 14 is f2, whereas the latter receiver 24 is
Is that the carrier wave frequency that can be received by is f1. That is, communication is performed with the rear transceiver 2 or roadside transceiver 3 of the preceding vehicle at the transmission frequency f1 and the reception frequency f2, and with the front transceiver 1 of the following vehicle, the transmission frequency f2 and the reception frequency f2. It is designed to communicate at f1. In other words, the communication path facing the traveling direction communicates at the frequency f1 and the communication path facing the opposite traveling direction communicates at the frequency f2.

This is for surely separating the communication path in the traveling lane and the communication path in the opposite lane.

In response to a command from the communication controller 6, the transmitters 11 and 21 generate transmission signals of carrier frequencies f1 and f2, respectively, and send them to the corresponding transmitting antennas 12 and 22, and transmit from the transmitting antennas 12 and 22. The radio waves are emitted and the timers 25 of the corresponding timers 25 are activated.

The receiving antennas 13 and 23 respectively receive signals of carrier frequencies f2 and f1 and send them to the corresponding receivers 14 and 24 and angle measuring devices 16 and 26, respectively. Each of the receivers 14 and 24 demodulates the information (data packet) contained in the received signal and gives it to the common communication controller 6, and detects the synchronization pattern contained in the information to generate a trigger. , Corresponding timers 15 and 2
The time measurement time of 5 is read out. Each of the angle measuring devices 16 and 26 measures the arrival direction of the received signal.

FIG. 3 is a block diagram of the roadside device of this embodiment including the roadside transceiver 3 described above.

The roadside device comprises a roadside transceiver 3, a communication controller 8 and a network connection device 9. The roadside transceiver 3 is
It has the same structure as the rear transceiver 2 of the vehicle shown in FIG. That is, the transmitter 31, the transmitting antenna 32, the receiving antenna 33, the receiver 34, the timer 35, and the angle measuring device 3
6 and the function of each part is the same as the corresponding element in the rear transceiver 2 of the vehicle, and the description thereof will be omitted.
The communication controller 8 is connected to the roadside transceiver 3 and the network connection device 9 and controls communication between the roadside fixed network and the vehicle. The network connection device 9 has an interface function with a fixed roadside communication network for interconnecting a group of roadside devices.

FIG. 4 is a block diagram showing the detailed structure of the transmitter i1 (i is 1 to 3) provided in the front transceiver 1, the rear transceiver 2, or the roadside transceiver 3 in this embodiment. is there.

The transmitter i1 (i is 1 to 3) outputs data from the packet configurator 41, which assembles the data given from the communication controller 6 or 8 into a data packet containing the data. A sync detector 42 which detects a sync pattern in a data packet to generate a trigger, a modulator 43 which modulates a radio carrier (carrier frequency is f1 or f2) by the data packet, and an output of this modulator 43 The power amplifier 44 amplifies the power and supplies it to the transmitting antenna i2.

FIG. 5 is a block diagram showing the detailed construction of the angle measuring device i6 and the receiving antenna i3 provided in the front transceiver 1, the rear transceiver 2 or the roadside transceiver 3 of this embodiment. is there.

The receiving antenna i3 is composed of two horn antennas i31 and i3 provided in parallel with the traveling surface.
It consists of two. Each horn antenna i31, i3
The received signals of 2 are given to the angle measuring device i6. For the receiver i4,
The reception signal of one horn antenna i31 or i32 is given.

The angle measuring instrument i6 includes a 90-degree phase shifter 5
1, an adder 52, two square-law detectors 53 and 54, and an angle calculator 55.

The reception signal from one horn antenna i32 is phase-shifted by 90 degrees via the 90-degree phase shifter 51 and added to the adder 52, and the reception signal from the other horn antenna i31 is added to the adder 52 and the adder 52. It is given to the square-law detector 54. The adder 52 adds and synthesizes the two input signals and gives the squared detector 53. The square-law detectors 53 and 54 are
The squared detection signal for the input signal is obtained and given to the angle calculator 55. The angle calculator 55 applies a predetermined arithmetic expression to these two squared detection signals to obtain and output measurement data in the arrival direction of the received signal.

FIG. 6 is an explanatory view of the principle of measuring the angle (arrival direction) by the angle measuring instrument i6. The distance between the center points of the two horn antennas i31 and i32 of the reception antenna i3 is d, the arrival direction of the reception signal is θ with respect to the directional center axis of the antenna, the wavelength of the radio wave is λ, the signal amplitude is A, and the circular constant is. Be π. Since the distance to the communication partner (the preceding vehicle, the following vehicle, or the roadside device) is significantly longer than the distance d between the center points of the two horn antennas i31 and i32, the radio waves captured by the two horn antennas i31 and i32 are Can be considered parallel. Therefore, the two horn antennas i31 and i
The propagation distances of the captured radio waves of 32 differ by d sin θ, and when converted into phases, they differ by 2πd sin θ / λ. Therefore, the output signal a from the square-law detector 53, which is square-law detected with respect to the output signal from the adder 52, can be expressed by the equation (1). On the other hand, the output signal b from the square-law detector 54, which is square-law detected with respect to the received signal, can be expressed by the equation (2).

[0035] From ^{a = A 2 {1 + sin} (2πd sinθ / λ)} ... (1) b = A 2/2 ... (2) These two equations, the angle calculator 55, performs operations according (3) From this, it can be seen that the arrival direction θ of the received signal can be obtained.

Θ = sin ⁻¹ {λ sin ⁻¹ (a / 2b−1) / 2πd} (3) FIG. 7 shows the front transceiver 1, rear transceiver 2 or roadside transceiver 3 in this embodiment. It is a block diagram which shows the detailed structure of the receiver i4 provided in the inside.

In FIG. 7, the receiver i4 is an amplifier 6
1, demodulator 62, packet decomposer 63 and sync detector 6
4. A reception signal from one horn antenna of the reception antennas is given to an amplifier 61 and amplified, and then demodulated by a demodulator 62 into a data form. The synchronization detector 64 detects a synchronization pattern from such demodulated data, and the detection result is output as a trigger for stopping the operation of the timer i5. The packet decomposer 63 extracts desired data from the demodulated data (data packet) from the demodulator 62 and extracts the desired data.
Or it is given to 8.

FIG. 8 is a format diagram showing the structure of each type of data packet of this embodiment.

This communication system uses four types of data packets. An inquiry packet whose structure is shown in FIG. 8A, a response packet whose structure is shown in FIG. 8B, and FIG.
There are a response confirmation packet having the configuration shown in (c) and a reconfirmation packet having the configuration shown in FIG. 8 (d).

In FIG. 8, a synchronization code SYNC is provided at the head of each packet in every packet, and this synchronization code SYNC is a code having a unique pattern that does not appear elsewhere. The synchronization detector 42 or 64 described above
Detects this synchronizing signal SYNC.

Next to the synchronization code SYNC, a code Q (inquiry packet), R (response packet), RA (response confirmation packet) or A (reconfirmation packet) indicating the packet type is inserted.

The sender identification code ID is inserted next, and the message number MSSN is inserted next.
Is inserted. The sender identification code ID is a number unique to each vehicle and each roadside transceiver. Message number MSS
N has a fixed value in one communication (consisting of a response packet, a response confirmation packet, and a reconfirmation packet for one inquiry packet), and is updated to the next value of the sequence number when the communication proceeds. It is something.

The RID provided in the response packet, the response confirmation packet, and the reconfirmation packet is the same as the source identification code ID included in the packet received immediately before is inserted as it is. It has been prescribed.

The OFS provided in the response packet and the response confirmation packet is the offset time taken from the immediately preceding received packet to the transmission of the next transmitted packet. The offset time OFS is used for calculating the distance between vehicles. The offset time OFS is not fixed and may be changed depending on the communication status.

The data DATA provided in the inquiry packet and the response packet is data to be transmitted / received by the communication terminal, information terminal, etc. of each vehicle, and data relating to the states of other vehicles necessary for group traveling and automatic traveling of vehicles. Etc.

The code error detection bit CRC provided at the end is a code for judging whether or not a code error has occurred in the entire packet and correcting the error if possible. Data packets that cannot be corrected even by the correction operation using the code error detection bit CRC are discarded.

(A-2) Operation of Embodiment FIG. 9 shows an example of the communication sequence of the vehicle communication system of this embodiment. The vehicle of this embodiment will be described below with reference to FIG. 9 as well. The operation of the communication system will be described. Note that FIG. 9 shows a case where there is no packet collision in each transmitter / receiver, and the name of the packet is shown although it is transmitted by a modulated signal in the wireless transmission path. Further, in the following explanation of the operation, in order to clarify the difference between the vehicles and the like, s is added to the end of the code indicating the configuration of the following vehicle, and t is added to the end of the code indicating the configuration of the preceding vehicle. In addition, u is added to the end of the reference numeral indicating the configuration of the roadside device.

Under the control of the communication controller 6, each traveling vehicle has a front transceiver 1 (1 in FIG. 9) at regular intervals (T).
(indicated by s), an interrogation signal of a predetermined frequency f1 (modulation signal by interrogation packet Q1) is transmitted, and the internal timer 15s starts timing.

At this time, in the transmitter 11s, the inquiry packet Q1 shown in FIG. 8A is assembled by the packet composer 41s based on the data sent from the communication controller 6s, and the transmission trigger from the communication controller 6s is generated. This inquiry packet Q1 is sent to the modulator 43s in a bit-serial manner and is subjected to two-phase phase modulation. This modulated signal (inquiry signal) is power-amplified by the power amplifier 44s, and then the transmitting antenna 1
It is transmitted from 2s. Further, the inquiry packet Q1 output from the packet composer 41s is also given to the synchronization detector 42, a trigger is generated at the time t0 when the synchronization code SYNC is transmitted, and the time counting by the timer 15s is activated.

The rear transceiver 2t of the preceding vehicle, which has received the inquiry signal related to the inquiry packet Q1, measures the arrival direction of the inquiry signal by the angle measuring device 26t and gives the result to the communication controller 6t. Under the control of the communication controller 6t, a response signal of the frequency f2 (response packet R11
(Modulation signal according to the above), and at the same time the timer 25t starts counting from the start of this return. Similarly, the roadside transceiver 3u that has received the interrogation signal measures the arrival direction of the interrogation signal with the angle measuring device 36u, gives the result to the communication controller 8u, and under the control of the communication controller 8u. , A response signal of frequency f2 (modulation signal by response packet R12) is returned from the time when the rearward offset time OFS12 set to the self has elapsed from the time of reception, and a timer is started from the time when this return is started. Activate 35u clock.

The operation of the angle measuring devices 26t and 36u is performed according to the above-mentioned operation principle. Further, the interrogation signal is sent to the amplifiers 61t,
61u, demodulators 62t and 62u, the packet is decomposed and demodulated and returned to the interrogation packet Q1.
The inquiry packet Q1 is decomposed by t and 63u based on the synchronization detection signals from the synchronization detectors 64t and 64u, and is given to the communication controllers 6t and 8u.

The communication controllers 6t and 8u, via the input / output device 7t or the network connection device 9u, send the decomposed data together with the source code ID and the message number MSSN obtained by the decomposition. It is given to input / output terminals and fixed roadside networks. Further, the communication controllers 6t and 8u are provided with the data given from the input / output terminal or the roadside fixed network via the input / output device 7t or the network connection device 9u, or the transmission source code I obtained by the decomposition.
D and the message number MSSN, and the offset time OFS11, O for the rearward set to the self at that time
The FS 12 is given to the transmitters 21t and 31u to activate the transmission of the response signal. The operation of the transmitters 21t and 31u at this time is almost the same as the operation when the transmitter 11s forms the interrogation signal, and thus the description thereof is omitted.

Here, the response signal from the rear transceiver 2t of the preceding vehicle (corresponding to the response packet R11) and the response signal from the roadside transceiver 3u (corresponding to the response packet R12) are the same as before the transmission of the inquiry signal. The inquiry signal is transmitted due to the difference in the distance between the transmitter / receiver 1s mounted on the vehicle and the transmitter / receiver, the difference in the backward offset time set for the transmitter / receiver that transmitted the response signal at that time, and the like. It is assumed that the front transceiver 1s arrives with a time difference that allows reliable discrimination.

The front transmitter / receiver 1s which has received the response signal (corresponding to the response packet R11) from the rear transmitter / receiver 2t of the preceding vehicle is counted by the timer 15s at the time of reception.
1 is output to the communication control unit 6s, the direction of arrival by the angle measuring device 16s based on the response signal is output to the communication control unit 6s, and the rear transceiver 2t of the preceding vehicle is output.
A response confirmation signal (corresponding to the response confirmation packet RA11) directed to is transmitted.

The front transceiver 1s also performs the same operation when receiving the response signal (corresponding to the response packet R12) from the roadside transceiver 3u. That is, the time T2 of the timer 15s at the time of reception is output to the communication control unit 6s, the measurement value of the arrival direction by the angle measuring device 16s based on the response signal is output to the communication controller 6s, and the roadside transceiver is also used. A response confirmation signal for 3u (corresponding to the response confirmation packet RA12) is transmitted.

The operation upon receiving such a response signal will be described in more detail below. The angle measuring device 1
The operation of 6s is performed according to the above-mentioned operation principle, and therefore its explanation is omitted. Also, the rear transceiver 2t of the preceding vehicle
The case where the response signal (corresponding to the response packet R11) from is received is described as an example.

In the receiver 14s, the response signal is amplified and demodulated by the amplifier 62s and the demodulator 63s and returned to the response packet R11. Then, the packet decomposer 63s detects the response signal Rs based on the synchronization detection signal from the synchronization detector 64s. The response packet R11 is decomposed and given to the communication controller 6s. The above-mentioned synchronization detection signal is given to the timer 15s, and the measured time T1 is sent to the communication control unit 6s. The communication controller 6s recognizes that the response packet is addressed to itself based on the decomposed packet type R and the destination identification code RID. Further, it recognizes that the source of the response packet R11 is the rear transceiver 2t of the preceding vehicle based on the decomposed source identification code ID. In addition, the communication controller 6s calculates the distance between the transmitter / receiver 2t of the preceding vehicle from the difference between the time measured by the timer 15s (time measured initially) T1 and the decomposed offset time OFS11. , The relative position between the preceding vehicle and the host vehicle is calculated in combination with the measurement value (first measurement value) in the arrival direction of the response signal. The position information and the data obtained by the packet decomposition are given to the input / output terminal via the input / output device 7s together with the source identification code ID and the message number MSSN obtained by the decomposition.

Further, the communication controller 6s has a source identification code ID and a message number MSSN obtained by the decomposition.
Alternatively, the forward offset time OFS13 set to the self at that time is given to the transmitter 11s to activate the transmission of the response confirmation signal (modulation signal of the response confirmation packet RA11). Since the operation of the transmitter 11s at this time is almost the same as the operation of transmitting the inquiry signal, the description thereof will be omitted.

The response signal from the roadside transmitter / receiver 3u is processed in the same manner to obtain the relative position information of the own vehicle with respect to the roadside transmitter / receiver 3u based on the time count T2 and the like, and input via the input / output device 7s. Send to the output terminal and transmitter 11
A response confirmation signal (modulation signal of the response confirmation packet RA12) addressed to the roadside transceiver 3u is transmitted from s. When the absolute position information of the roadside transceiver 3u is inserted in the data part of the response packet R12, the absolute position information of the host vehicle can be obtained.

Further, the distance between the preceding vehicle and the own vehicle does not substantially change, whereas the distance between the roadside transceiver 3u and the own vehicle changes. Therefore, the distance calculation formula should be changed in consideration of this point. Alternatively, the speed of the own vehicle may be taken in via the input / output device 7s to obtain the distance between the roadside transceiver 3u and the own vehicle.

Response confirmation signal (response confirmation packet RA11
The rear transmitter / receiver 2t of the preceding vehicle, which has received the signal), provides the communication controller 6t with the time T11 measured by the timer 25t at the time of reception, and communicates the measurement value of the direction of arrival of the received signal by the angle measuring device 26t. It is given to the controller 6t so that the relative position of the following vehicle can be captured by the communication controller 6t, and a reconfirmation signal (modulation signal of the reconfirmation packet A11) which is a confirmation signal for the response confirmation signal is transmitted.

Similarly, the roadside transmitter / receiver 3u, which has received the response confirmation signal (corresponding to the response confirmation packet RA12), provides the communication controller 8u with the time T12 measured by the timer 35u at the time of reception, and the angle measuring device 36u. The measured value of the direction of arrival of the received signal is given to the communication controller 8u,
The communication controller 8u captures the relative position of the vehicle that transmits the response confirmation signal, and also transmits the reconfirmation signal (modulation signal of the reconfirmation packet A11) that is the confirmation signal for the response confirmation signal.

The operation when receiving the response confirmation signal will be described in more detail below. The operation of the angle measuring devices 26t and 36u is performed according to the above-mentioned operation principle, and therefore its description is omitted. Further, the rear transceiver 2t of the preceding vehicle transmits a response confirmation signal (response confirmation packet RA1
(Corresponding to 1) will be described as an example.

The response confirmation signal is received by the receiver 24t.
After being amplified and demodulated by the amplifier 62t and the demodulator 63t and returned to the response confirmation packet RA11, the synchronization detector 6
Based on the 4t synchronization detection signal, the packet decomposer 6
It is decomposed by 3t and given to the communication controller 6t.
Further, the above-mentioned synchronization detection signal is given to the timer 25t to cause the communication control unit 6t to send out the measured time T11. The communication controller 6t recognizes that the response confirmation packet is addressed to itself based on the decomposed packet type RA and the destination identification code RID. Further, based on the decomposed transmission source identification code ID, it is recognized that the transmission source of the response confirmation packet R11 is the front transceiver 1s of the following vehicle that has transmitted the inquiry signal immediately before. Further, the communication controller 6t calculates the distance between the transmitter / receiver 1s of the following vehicle from the difference between the measured time T11 of the timer 25t and the decomposed offset time OFS13, and measures the arrival direction of the response confirmation signal. The relative position between the following vehicle and the host vehicle is calculated in combination with the value (first measured value). Such position information is given to the input / output terminal via the input / output device 7t, together with the source identification code ID and the message number MSSN obtained by the decomposition.

Further, the communication controller 6t has the transmission source identification code ID and the message number MSSN obtained by the decomposition.
Alternatively, the rearward offset time OFS11 set to the self at that time is given to the transmitter 21t to start the transmission of the reconfirmation signal (the modulation signal of the reconfirmation packet A11). Since the operation of the transmitter 21t at this time is almost the same as the operation of transmitting the response signal, the description thereof will be omitted.

The roadside transceiver 3u also performs the same processing on the received response confirmation signal. That is,
The relative position information of the transmission vehicle of the signal is obtained based on the time count T12 and the like and is given to the fixed network side via the network connection device 9u, and the re-confirmation signal (re-confirmation packet A12) is set to the transmission vehicle. The modulated signal of 1) is transmitted from the transmitter 31u.

A response confirmation signal for the roadside transceiver 3u also reaches the rear transceiver 2t of the preceding vehicle, and
Although the response confirmation signal directed to the rear transceiver 2t of the preceding vehicle also reaches the roadside transceiver 3u, each transceiver 2t, 3u
The communication controllers 6t and 8u recognize that the packet is addressed to another transmitter / receiver based on the destination identification code RID of the response confirmation packet obtained by demodulation, and determine the response confirmation packet. Is not executed.

The front transceiver 1s (communication controller 6s) of the following vehicle, which receives the reconfirmation signal (corresponding to the reconfirmation packet A11) from the rear transceiver 2t of the preceding vehicle, is connected to the rear transceiver 2t of the preceding vehicle. It recognizes that the one-time communication has ended, and this front transceiver 1s (communication controller 6s)
When the reconfirmation signal (corresponding to the reconfirmation packet A12) is received from the roadside transceiver 3u, the roadside transceiver 3
Recognize that one contact with u is complete. And
Preparation for transmission such as preparation of the next inquiry packet Q1a in which the message number MSSN is incremented by 1 is carried out, and the next transmission time t1 is awaited.

Even when the reconfirmation signal is received, the relative position with respect to the rear transceiver 2t, the roadside transceiver 3u, etc. of the preceding vehicle is obtained based on the elapsed time from the time of transmitting the response confirmation signal. Is also good.

On the other hand, the roadside transceiver 3u and the rear transceiver 2t of the preceding vehicle send a response packet if the inquiry packet is received without error, wait for the arrival of the response confirmation packet, and receive the response confirmation packet without error. If so, a reconfirmation packet is sent to complete one communication. If the communication is completed normally, the data part DA of the response packet
The data to be inserted in the TA is updated to the next data to prepare for the next communication.

As described above, in this embodiment, a question packet, a response packet, and a response confirmation packet are transmitted between the front transceiver 1s of the following vehicle and the rear transceiver 2t of the preceding vehicle or the roadside transceiver 3u. By sending and receiving the reconfirmation packet in this order, desired data can be sent and received, and the following vehicle can obtain relative position information with respect to the preceding vehicle or the roadside transceiver. Can obtain relative position information with the following vehicle,
Further, the roadside transceiver can obtain relative position information with respect to the traveling vehicle.

The example of the operation in the case where the communication is normally completed without the packet collision or the like has been described above.
The operation when communication does not end normally, such as when a packet collision occurs, will be described.

The front transmitter / receiver 1 and the communication controller 6 of the following vehicle may not be able to recover the response packet or the reconfirmation packet due to data destruction due to collision of the response packet or the reconfirmation packet, or may not receive these packets. If the communication does not end normally, such as when there is no such message, the message number MSSN and the data DATA are not updated, and the same inquiry packet is retransmitted at the next transmission time.

If the response packet cannot be received within the allowed threshold time from the transmission of the inquiry packet, it is judged that the response packet cannot be received, and the transmission is started from the transmission of the response confirmation packet. If the reconfirmation packet cannot be received within the predetermined threshold time, it is determined that the reconfirmation packet cannot be received. The clocked time information for this determination also uses the clocked time by the timer 15.

If the rear transceiver of the preceding vehicle is in an abnormal state, the abnormal response packet is repeatedly received. In this case, the signal from the preceding vehicle is ignored or the data portion DATA of the inquiry packet is
The information for forcibly stopping the operation of the rear transmitter / receiver of the preceding vehicle is included in the above information and transmitted.

When the response packet is not received, the roadside transceiver 3 or the rear transceiver 2 of the preceding vehicle,
It is assumed that a collision with the interrogation signal transmitted from another vehicle has occurred. Since each traveling vehicle sends out an inquiry signal in the same cycle, there is a high possibility that the next inquiry signal will cause a collision. Therefore, in order to avoid the collision of the next question signal, the next transmission time is shifted based on the pseudo random number generated by the random number generator in the communication controller 6.

When the response packet is received but the reconfirmation packet is not received, it is considered that the response confirmation packet has collided in the roadside transceiver 3 or the rear transceiver 2 of the preceding vehicle. Then, the transmission time of the response confirmation signal corresponding to the next inquiry signal is shifted based on the pseudo random number generated by the random number generator in the communication controller 6. Also,
Offset time O of the response confirmation packet according to the shift amount
The FS is changed and the fact that it has been shifted is transmitted to the roadside transceiver 3 or the rear transceiver 2 of the preceding vehicle.

The roadside transceiver 3 and the communication controller 8 or
The rear transceiver 2 and the communication controller 6 of the preceding vehicle receive the inquiry signal when the inquiry packet is received but the response confirmation packet cannot be received (when the time measured by the timer 35 or 25 exceeds the allowable threshold time). It is considered that a collision of response packets has occurred in the front transmitter / receiver 1 of the vehicle that transmitted the message, and the transmission time of the response packet for the next inquiry packet is set to a pseudo random number generated by the random number generator in the communication controllers 8 and 6. The offset time OFS of the response packet is changed according to the shift amount.

Service range of each roadside device (called cell)
If the roadside devices are installed so as to partially overlap each other, a continuous communication path can be formed between the roadside communication network and the traveling vehicle. In this case, in a portion where cells overlap, there are response signals from a plurality of roadside devices for one inquiry signal, but interference does not occur because the arrival times of the response signals are different. However, since a plurality of identical packets are sent to the roadside communication network, the roadside communication network or the partner vehicle discards redundant packets.

(A-3) Effects of the Embodiments As described above, according to the above embodiments, the traveling vehicles are
Also, since a continuous communication path without mutual interference is formed between the traveling vehicle and the roadside communication network, various kinds of communication terminals such as telephones and continuous information communication using the information terminal can be performed. It will be possible. At the same time, since the in-vehicle device and the roadside device have a position measuring function, position information of each traveling vehicle is obtained, and group traveling and automatic traveling of vehicles using this information are also possible. Therefore, one system can meet the requirements for both information communication and travel control, and can be widely used as an information communication infrastructure on the road. Also,
By using only the communication between the traveling vehicles and the position measurement function, it becomes possible to perform group traveling even on a road where no roadside device is installed.

(B) Other Embodiments In the above embodiment, the transmission frequencies of the roadside transceiver and the rear transceiver are equal, but the transmission frequencies of the roadside transceiver and the rear transceiver are changed, and the front portion is changed. As the receiving configuration of the transceiver, two systems may be provided, a configuration facing the roadside transceiver and a configuration facing the rear transceiver, so that interference of signals from the roadside transceiver and the rear transceiver can be reliably prevented. Similarly, the transmission frequency from the front transceiver may be changed depending on whether it is directed to the roadside transceiver or the rear transceiver. Even in this case, even the packet composer is shared.

In the above embodiment, the front transmitter / receiver has shown a plurality of parties to which it can communicate almost at the same time. However, communication is performed only with the party who has transmitted the first response signal to the inquiry signal. May be.

Further, in the above embodiment, the front transmitter / receiver sends the inquiry signal to start one communication, but the roadside transmitter / receiver sends the inquiry signal to send the inquiry signal. You may make it start the communication of the times.

Furthermore, in the above-described embodiment, the roadside device is provided with only the roadside transceiver that is oriented in the opposite direction to the traveling direction. However, in addition to this roadside transceiver, the roadside transceiver that is oriented in the traveling direction is shown. Device (similar configuration to the front transceiver of the vehicle) may be provided. In this case, the range of cells is expanded and the installation interval of roadside devices can be lengthened.

In the above embodiment, the horn antenna is used as the receiving antenna.
It is also possible to use another type of antenna such as a slot antenna or a microstrip antenna having a function equivalent to this. As the transmitting antenna, any of a horn antenna, a slot antenna, a microstrip antenna, etc. may be applied. Further, as the reception antenna and the transmission antenna, one transmission / reception shared antenna may be applied.

Further, in the above embodiment, the two-phase phase modulation method is applied as the digital modulation method of the data packet, but other modulation methods such as the four-phase phase modulation method can be used.

Further, the installation positions of the front transmitter / receiver and the rear transmitter / receiver provided in the vehicle are not limited to the positions shown in FIG. 1, but may be provided in the central portion of the roof or the like. In short, if the front transceiver can communicate with the transceiver existing in the front in the traveling direction, and the rear transceiver can communicate with the transceiver existing in the rear opposite to the traveling direction. The installation position is arbitrary.

Further, in the above-mentioned embodiment, the transmission frequency and the reception frequency of the transceiver mounted on the vehicle are shown as fixed, but they may be variable. For example, the frequencies used for the up lane and the down lane of an expressway are divided, and each vehicle switches the frequency manually or automatically when traveling in the up lane and in the down lane. You can

[0089]

As described above, according to the present invention, various kinds of information can be transmitted and received by exchanging a signal obtained by modulating a data packet between a roadside transceiver and a transceiver mounted on a vehicle. In addition to being able to send and receive, the relative position information can be obtained mutually depending on the round-trip time and the direction of arrival of the modulated signal, and the signals in which data packets are modulated are exchanged between the transmitters and receivers mounted on different vehicles. By
Since various kinds of information can be transmitted and received, and relative position information can be obtained mutually by the round-trip time and the direction of arrival of the modulated signal, without providing a communication configuration for each information type,
A lot of information can be transmitted and received between road vehicles and between vehicles, and group travel control and automatic travel control using relative position information obtained by using such a common communication configuration can be realized.

[Brief description of drawings]

FIG. 1 is a bird's-eye view of a road showing a schematic configuration of a vehicle communication system according to an embodiment.

FIG. 2 is a block diagram showing a communication configuration of the vehicle of the embodiment.

FIG. 3 is a block diagram illustrating a communication configuration of a roadside device according to an embodiment.

FIG. 4 is a block diagram showing a transmitter configuration in various transceivers of the embodiment.

FIG. 5 is a block diagram showing a configuration of an angle measuring device in various transceivers of the embodiment.

FIG. 6 is a supplementary explanatory view of the principle of angle measurement.

FIG. 7 is a block diagram showing a receiver configuration in various transceivers of the embodiment.

FIG. 8 is a format diagram showing a data packet configuration of the embodiment.

FIG. 9 is a sequence diagram showing a communication sequence example of the embodiment.

[Explanation of symbols]

1 ... front transceiver, 2 ... rear transceiver, 3 ... roadside transceiver, 6, 8 ... communication controller, 11, 21, 31 ... transmitter,
12, 22, 32 ... Transmitting antennas, 13, 23, 33 ...
Reception antennas, 14, 24, 34 ... Receivers, 15, 2
5, 35 ... Timer, 16, 26, 36 ... Angle measuring device, 4
1 ... Packet configuration unit, 42, 64 ... Sync detector, 51 ...
90-degree phase shifter, 52 ... Adder, 53, 54 ... Square-law detector, 55 ... Angle calculator, 63 ... Packet decomposer.

Claims (4)

[Claims] 1. A vehicle communication system for providing a wireless communication path between vehicles traveling on a road and between a vehicle and a roadside communication network, the first communication system directing a traveling direction to the vehicle. The transceiver is mounted with a second transceiver oriented in the opposite direction to the traveling direction, and a transceiver connected to the roadside communication network is provided on the roadside at predetermined intervals. Respective transmission / reception means of the data packet, the difference between the transmission time of the signal which itself carries the data packet of the transmission source and the reception time of the reply signal which carries the reply data packet by the partner transceiver for the data packet, and A relative position detecting means for measuring an incident angle of a signal from a partner transceiver and obtaining relative position information between the self transceiver and another transceiver based on the measured value. Both communication system. 2. The incident angle measuring configuration of the response signal in the relative position detecting means comprises two horn antennas or a receiving antenna having a function equivalent thereto, and one output of the receiving antenna is phase-shifted by 90 degrees. Angle measurement for calculating an angle based on a first post-detection output obtained by performing square-law detection after addition with the other output and a second post-detection output obtained by performing square-law detection of one output of the receiving antenna The vehicle communication system according to claim 1, further comprising: 3. Each of the data packet transmitting / receiving means, when it cannot receive a reply signal of a certain type from the partner transceiver, determines the next transmission time of the transmission signal from itself of the kind that seeks the reply signal based on a pseudo random number. The vehicle communication system according to claim 1, which is shifted. 4. A vehicle capable of constructing a vehicle communication system for providing a wireless communication path between vehicles traveling on a road and between a vehicle and a roadside communication network, the vehicle being capable of directing a traveling direction. The transmitter / receiver 1 and the second transmitter / receiver pointing in the opposite direction to the traveling direction are mounted, and each transmitter / receiver of each type has a data packet transmitting / receiving means and a signal which carries the data packet of the transmission source. Of the transmission time and the reception time of the reply signal carrying the reply data packet by the partner transceiver for the data packet, and the incident angle of the signal from the partner transceiver is measured, based on the measured value, A vehicle having a relative position detecting means for obtaining relative position information between a self-transceiver and another transceiver.