JP3000826B2 - In-vehicle receiver for road-to-vehicle communication - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road-to-vehicle communication for exchanging various road information and performing navigation for recognizing a vehicle position by communicating with a road station installed at a distance specified along a road. And a vehicle receiver.

[0002]

2. Description of the Related Art In order to recognize the current position of a vehicle for navigation along with various road information and the like, a road station that outputs transmission radio waves at specified distances along a road on which the vehicle runs is installed. Road-to-vehicle communication between the road station and vehicles running on the road has been considered.

In such road-to-vehicle communication, a road station 42 is provided at a predetermined interval (for example, an interval of several hundred meters to several kilometers) along a road 41 as shown in FIG.
Communication area formed by the antenna 43 of this road station 42
It has a function of wirelessly communicating with a transceiver mounted on a vehicle 45 passing through 44. Here, the communication area 44 set on the road is, for example, about 1 to 4 lanes in lane width and about 70 m in the traveling direction distance of the vehicle 45.

In the vehicle 45, the communication area 44
, The vehicle-mounted transceiver communicates with the road station 42, and the road station transmitted from the road station 42
42 unique information is transmitted to the navigation device connected to the onboard transceiver. In the navigation device, a service useful for the driver, such as correction of the current position of the vehicle 45 and road guidance based on the information transmitted from the road station 42, and further information such as traffic congestion information and regulations related thereto is provided. .

Here, the road station 42 employs an AM reverse-phase modulation system in order to accurately determine the position of the vehicle 45 and to identify the traveling direction. In the AM reverse-phase modulation method, after the transmission data shown in FIG. 10 is data-modulated by a predetermined carrier in a data modulator 51, the first and second transmission data are modulated.
AM modulators 52 and 53.

In this case, for the second AM modulator 53,
The clock signal from the 1 KHz clock generation circuit 54 is transferred 180 ° by the transfer circuit 55 and supplied to the AM modulator 53,
And the second AM modulators 52 and 53 output an in-phase transmission wave and an anti-phase transmission wave, respectively.
432. That is, the in-phase and out-of-phase transmission waves are radiated in a region in front of the traveling direction of the vehicle 45 and a region opposite thereto with respect to the point P immediately below the antenna, which is the center of the communication region 44 shown in FIG. Become like

FIG. 11 shows the states of the in-phase transmission wave radiated from the antenna element 431 and the opposite-phase transmission wave radiated from the antenna element 432 in comparison with each other. AM modulation is performed so that the relationship with the phase becomes in-phase or out-of-phase.

That is, when the transceiver mounted on the vehicle 45 receives the transmission wave radiated from the antenna 43 and detects that the received AM modulated wave signal has changed from in-phase to out-of-phase, the vehicle 45 detects For example, it is recognized that the vehicle is traveling in the forward direction indicated by the arrow, and vice versa.
It is recognized that the vehicle 45 is traveling in the direction opposite to the arrow, and by reading the change in the phase relationship of the AM modulation signal together with the identification of the traveling direction, the vehicle 45 reaches the point P immediately below the antenna. Is recognized.

When such road-to-vehicle communication is performed, the position detection and direction identification of the traveling vehicle are performed by the phase comparison output of the AM modulated wave. However, when the output of the phase comparison unit becomes unstable, the position is determined. This may cause a malfunction in detection and direction identification. For this reason, in order to achieve the stable operation, it is considered that a pulse-like signal of a predetermined time t1 or less is determined as noise and processed. However, if such a means is used, noise having a pulse width of t1 or more is considered. Is not performed, and when such a noise having a large pulse width occurs, the occurrence of a malfunction cannot be prevented.

In particular, when the vehicle is traveling at a low speed, a multipath or time-interrupted radio signal is likely to generate a pulse-like noise signal exceeding time t1, resulting in incorrect position detection or direction identification. Will cause problems. Since such information is used for navigation of a vehicle, a means for reliably preventing occurrence of a malfunction is desired.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and is particularly useful in detecting a position or identifying a traveling direction by a phase comparison output. Even in a state where noise is mixed, identification of the position of the vehicle and identification of the direction can be executed with reliability, so that occurrence of a malfunction in an on-vehicle navigation device or the like can be prevented reliably. It is intended to provide a receiving device.

[0012]

SUMMARY OF THE INVENTION In vehicle receiving apparatus in the road-vehicle communication according to the present invention, from the road station installed along the road, that in the longitudinal direction modulation phase in the boundary immediately below the road station opposite In a road-to-vehicle communication system in which a modulated signal is transmitted as a phase and the signal is received by a vehicle traveling on the road, the modulation phase of a signal received from the road station is determined, and the position with respect to the road station is determined. Position / direction identifying means for detecting and determining the traveling direction of the vehicle, and sampling signal generating means for generating a sampling signal every time the vehicle traveling on the road travels a specified distance,
The identification signal from the position / direction identification means corresponding to the sampling signal is sampled by the specified sampling number, and the position and direction identification means for identifying the position and the traveling direction by the logical judgment of the sampling result. And area identification means for receiving a transmission signal from a roadside station, detecting a carrier signal level of the reception signal with the specified sampling number of the sampling signal, and identifying a communication area by logical judgment thereof.
And the position / direction identification means makes the vehicle
From the time when it is recognized as being at the lower position, the area recognition means
The above corresponds to the delay time until the communication area is certified in
Error detecting means for transmitting the moving distance of the vehicle as error information
And the identified vehicle together with the error information.
Navigation based on the position and traveling direction and the error information
The information processing is performed.

[0013]

According to the on-vehicle receiver for road-to-vehicle communication configured as described above, a plurality of position detection and direction detection signals are sampled by a sampling signal corresponding to the traveling distance of the vehicle, and the logical judgment of the sampling signal is determined. Done. Therefore, even if a pulse-like noise signal is mixed in the reception signal, an accurate position detection / direction identification signal not affected by the noise signal can be obtained. Further
And the travel distance corresponding to the delay time is transmitted as error information
In addition, since the navigation information processing is performed, the processing in the vehicle by the road-to-vehicle communication is executed with high accuracy and reliability. For example, the navigation device mounted on the vehicle is controlled with high accuracy and the navigation for the driver is reliably performed.
It will be executed with sexuality .

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a road-to-vehicle communication receiving apparatus mounted on a vehicle, and includes a receiving antenna 11 for receiving a transmission signal from an antenna 43 of a road station 42 shown in FIG. The signal received by the antenna 11 is appropriately amplified in the high frequency section 12 and the intermediate frequency section 13 and the data is demodulated.
14, 1 KHz Commonly supplied to the demodulation unit 15 and the level detection unit 16.

The output data signal from the data demodulation unit 14 is input to a synchronization detection unit 17, and this synchronization detection unit
At 17, the head position of the data frame as shown in FIG. 11 is detected, and a signal synchronized with the head of this data frame is sent to the reference 1 KHz creating unit 18. The reference 1 KHz creating section 18 creates a reference 1 KHz signal synchronized with the head position of the data frame detected by the synchronization detecting section 17. The reference 1 KHz signal is a 1 KHz signal demodulated by the 1 KHz demodulation section 15. Along with this, the signal is sent to a phase comparator 19, which compares the phase of the reference 1 KHz signal with the demodulated 1 KHz signal. The phase detection unit 19 outputs a position detection / direction identification signal A corresponding to the phase comparison result, and the signal A is input to the sampling unit 20.

The phase comparator 19 compares and determines whether the leading phase of the data frame and the phase of the 1 KHz signal are the same phase or the opposite phase as shown in FIG. When the head of the data frame is in phase with the 1 KHz signal, that is, when the reference 1 KHz signal and the demodulated 1 KHz signal are in phase, a logic level "0" is output from the phase comparison unit 19 as shown in FIG. . When the head of the data frame and the 1 KHz signal have an opposite phase relationship, the signal of the logical level "1" is output from the phase comparing section 19.

In a normal running state, such a stable output of logic "0" or "1" is output from the phase comparator 19 in accordance with the vehicle position in the communication area. When multi-pulse fading or radio wave cut-off occurs in cases such as when a vehicle runs in parallel, a waveform in which pulse-like noises MP1 to MP5 are mixed in the received signal as shown in FIG. Becomes
Depending on the pulse width of such noises MP1 to MP5, malfunctions such as incorrect position estimation or direction identification may occur.

In order to deal with the problem of such malfunction,
The output signal from the phase comparison unit 19 is supplied to the sampling unit 20, and the output from the comparison unit 19 is sampled in accordance with the pulse signal from the distance signal generation unit 21. To do.

A distance signal generator 21 for generating a sampling signal generates a pulse signal F every time the vehicle travels a specified distance. The distance signal generator 21 generates such a sampling signal F. Reference numeral 21 denotes a mechanism that generates a pulse-like signal for each specified rotation of the wheel, and the vehicle generates one pulse signal for each specified distance (for example, about 0.4 m).

FIG. 3 shows a sampling section 20 and a phase determination section.
This shows an example of a circuit configuration of 22. For example, the sampling unit 20 is configured by configuring a shift register by three-stage flip-flops 201 to 203. That is, the position detection / direction identification signal A from the phase comparator 19 is input to the D terminal of the first flip-flop 201, and the output of the Q terminal is sequentially supplied to the D terminal of the next flip-flop. I have. Then, the sampling signal F is input to the CK terminal of each of the flip-flops 201 to 203.

The phase determining section 22 includes flip-flops 201 to 201
202, a first NAND circuit 221 to which outputs B to D from respective Q terminals are supplied, and flip-flops 201 to 20
3 A second NAND circuit 222 to which an output from each / Q (/ indicates negative logic) terminal is supplied, and a NAND circuit to which an output from each of the NAND circuits 221 and 222 is supplied
The judgment output is obtained by the logic judgment circuit of 223 and 224.

That is, in correspondence with the sampling signal F, the position detection / direction identification signal A from the phase comparison section 19 is sampled and sequentially shifted and stored in flip-flops 201 to 202. ~
Reference numeral 203 denotes an n-bit shift register (3 bits in this case). Then, in the phase determination unit 22, the n bits (3
A stable signal E of the position detection / direction identification signal corresponding to the logic level state of the bit (1).

In this embodiment, the sampling unit 20
Is composed of 3 bits, so that the output of the shift register formed by the flip-flops 201 to 203 (in a state where the vehicle travels over a section of 1.2 m (0.4 m × 3)) is used. When B to D) match, a signal E for determining the stability of position detection and direction identification is determined.

FIG. 4 is a timing chart for explaining the operation of the sampling section 20 and the phase determination section 22 shown in FIG. 3, and a sampling signal F is generated every time the vehicle moves a specified distance. The Q outputs B to D from the flip-flops 201 to 203 constituting the 3-bit shift register sequentially delay the position detection / direction identification signal A from the phase comparator 19 by one pulse with the sampling signal F. And all of the signals B to D are "0".
At this time, the position detection / direction identification stable signal E output from the phase determination unit 22 becomes "1". That is, the phase comparison unit
Even if the position detection / direction identification signal A output from 19 operates in an unstable manner, a stable position detection / direction identification stable signal E is obtained, and malfunction can be prevented.

In the embodiment, the operation of stabilizing the position detection / direction identification signal has been described as being performed by the circuit device as shown in FIG. 3. However, it is needless to say that this operation is performed by software according to the above algorithm. It is also possible to process.

In the level detector 16 to which the received signal is supplied, a signal proportional to the signal level inputted to the receiving antenna 11 is inputted as shown in FIG. The level is compared with the set carrier detection level. Then, in the state where the received signal level becomes equal to or higher than the set carrier detection level, the signal shown in FIG.

That is, when the carrier detection signal G shown in FIG. 3B is a logical "1", it indicates that the vehicle 45 traveling on the road 41 is present in the predetermined communication area 44.
"0" indicates that the vehicle 45 is out of the communication area 44.

The data demodulated by the data demodulation unit 14, the position detection / direction identification stable signal E determined by the phase determination unit 22, and the determination result of the received signal level from the level detection unit 16 are sent to the data processing unit 23. Supplied to.

In the data processing section 23, a level detecting section
In this process, the carrier detection signal G from 16 is sampled and stored as a sampling signal F. When the vehicle is recognized as being the same during a certain distance L1, the input signal is determined. Then, L2
A stable carrier detection signal can be obtained even when a smaller noise pulse is deleted and a level change due to a multi-pulse as in the signal shown in FIG. Can be.

FIG. 6 shows the flow of processing in the data processing unit 23. First, in the data processing unit 23, the demodulated received data from the data demodulation unit 14 and the position detection / direction identification determined by the phase determination unit 22 are performed. Stable signal E, level detector 16
Carrier detection signal G determined in step 2 and a distance signal generator
The sampling signal from 21 is always input. In step 101, the vehicle is detected based on whether or not the input carrier detection signal G is stably "1".
It is determined whether or not the vehicle 45 has entered the communication area 44. If it is confirmed in step 101 that the vehicle 45 has entered the communication area 44, the data demodulation unit is determined in step 102.
Start receiving the data signal from 14.

In step 103, a change in the position detection / direction identification stable signal E from the phase determination section 22 is monitored, and the point at which the signal E changes is determined to be the position P immediately below the antenna. If it is determined that the current position is immediately below the antenna, the process proceeds to step 104 to check whether there is current position information. Then, if it is determined that there is current position information, a process of transmitting the received data from the data processing unit 23 to the navigation device 24 is performed.

If the data transmission line between the data processing unit 23 and the navigation device 24 has a bus structure, or if the navigation device 24 is not in a communicable state, the transmission line cannot be used immediately and the waiting time May occur. However, the vehicle 45 is moving during the waiting time, and the distance moved during the waiting time is an error. Further, in this embodiment, in order to obtain the position detection / direction identification
Since the direction identification signal A is sampled corresponding to the three sampling signals, an error of, for example, 1.2 m occurs between them. In step 105, a delay distance counter is started in order to correct errors due to these delays.

When it is determined in step 101 that the vehicle 45 is not in the reception area, and when it is determined in step 103 that the vehicle 45 is not directly below the antenna, step 10 is performed.
If it is determined in step 4 that there is no current position information and it is determined that the state is abnormal, the process returns to the start and the processing from step 101 is repeated.

In step 106, the state of the level of the position detection / direction identification stable signal E output from the phase determination section 22 is monitored, and based on the determination result that the signal E is "0" or "1". , The traveling direction of the vehicle 45 is determined. In this case, the direction identified for the road is identified as forward,
When it is determined in step 106 that the traveling direction is the forward direction, the process proceeds to step 107 to prepare for transmitting the reception data corresponding to the forward direction to the navigation device 24. Also,
If it is determined in step 106 that the vehicle 45 is traveling in the reverse direction, the process proceeds to step 108 to prepare for transmitting received data corresponding to the reverse direction to the navigation device 24.

In step 109, it is determined whether data transmission to the navigation device 24 is possible. If it is determined in step 109 that data transmission is possible, in step 110 the current position information and the value of the delay distance counter (started in step 105), which is the system distance error, are added and transmitted to the navigation device 24. . Accordingly, in the navigation device 24, sufficiently accurate position information is input.

Thereafter, at step 111, it is determined whether or not all the navigation data has been received. When it is determined that the reception has not been completed, the data reception is continued at step 112. If it is determined in step 111 that all of the navigation data has been received, the remaining data is transmitted to the navigation device 24 in step 113 so that all of the received data is transmitted to the navigation device 24. I do.

In the on-vehicle receiver of the road-vehicle information transmission system shown in this embodiment, the position detection / direction identification signal is sampled by the sampling signal based on the distance signal. Even in the case of instability, malfunction can be prevented by logically determining the n-bit (3 bits in the embodiment) sampling value, and an accurate signal immediately below the antenna and direction identification signal without erroneous determination can be obtained.

During the sampling of, for example, 3 bits, the vehicle needs to travel 1.2 m.
By transmitting the vehicle moving distance due to the distance of m and the delay until the start of transmission with the navigation device 24 to the navigation device 24 as error information, it is possible to provide accurate position information.

In the sampling unit 20 and the position judging unit 22 shown in FIG. 3, the flip-flops of the NOR circuits 223 and 224 are inverted when all the sampling values match, but as shown in FIG. Flip flop 20
The Q outputs from 1 to 203 may be supplied to the majority decision circuit 25, and the majority decision circuit 25 may obtain the position detection / direction identification stable signal E by logical decision as shown in FIG.

In FIGS. 7 and 8, the majority decision is made by using three bits. However, the configuration may be such that the number of bits is further increased, and the majority decision value is changed. Is also good.

[0041]

As described above, in the on-vehicle receiving apparatus for road-to-vehicle communication according to the present invention, the position detection and traveling of the traveling vehicle can be performed without being affected by various noises during the traveling of the vehicle and interruption of radio waves. Direction identification is performed with high accuracy and reliability, and navigation of a traveling vehicle using this type of communication is performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining a vehicle-mounted receiving device in road-to-vehicle communication according to an embodiment of the present invention.

FIGS. 2A and 2B are diagrams illustrating a position detection / direction identification signal in a normal state and when noise is mixed, respectively.

FIG. 3 is a diagram showing a specific configuration example of a sampling unit and a phase determination unit of the embodiment.

FIG. 4 is a timing chart illustrating operations of the sampling unit and the phase determination unit.

FIG. 5 is a signal waveform diagram illustrating a reception level and carrier detection.

FIG. 6 is a flowchart illustrating an operation of the receiving device.

FIG. 7 is a diagram illustrating another configuration example of the sampling unit and the phase determination unit.

FIG. 8 is a view for explaining majority logic in FIG. 7;

FIG. 9 illustrates a road-vehicle communication system.

FIG. 10 is a diagram illustrating a transmission unit in the road-to-vehicle communication system.

FIG. 11 is a diagram illustrating a transmission signal.

[Explanation of symbols]

11 ... receiving antenna, 12 ... high frequency part, 13 ... intermediate frequency part, 14
... Data demodulator, 15 ... 1KHz demodulator, 16 ... Level detector, 17 ... Synchronization detector, 18 ... Reference 1KHz generator, 19 ...
Phase comparing section, 20 sampling section, 21 distance signal generating section, 22 phase determining section, 23 data processing section, 24 navigation apparatus, 41 road, 42 road station, 43 antenna, 44
... communication area, 45 ... vehicle.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-40898 (JP, A) JP-A-6-317642 (JP, A) JP-A-5-314394 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G08G 1/00-1/16

Claims (1)

(57) [Claims] From 1. A road station installed along a road, the modulation phase in the longitudinal direction as a boundary immediately below the road station sends a modulated signal which is reverse phase to the signal traveling the road In a road-to-vehicle communication system adapted to be received by a vehicle, position / direction identification means for determining a modulation phase of a reception signal from the road station, detecting a position with respect to the road station, and determining a traveling direction of the vehicle. Sampling signal generating means for generating a sampling signal each time a vehicle traveling on the road travels a specified distance; and identifying an identification signal from the position / direction identifying means in response to the sampling signal. Sampling by sampling number
Ring, and a position and direction determining means for determining a position and a traveling direction by logical determination of the sampling result ; and a transmitting signal from the roadside station, and a carrier of the receiving signal at a specified sampling number of the sampling signal. An area recognition unit for detecting a signal level and determining a communication area based on a logical determination of the signal, and the position / direction identification unit determines that the vehicle is located immediately below the road station.
From the area recognition means,
The vehicle corresponding to the delay time until the communication area is certified
Error detection means for transmitting the travel distance of the as error information,
And the identified vehicle position and travel together with the error information
Navigation information processing based on direction and the error information
The in-vehicle receiving apparatus in road-to-vehicle communication characterized by performing.