JPH11185083A - Communication equipment at toll gates - Google Patents

Abstract

(57) [Summary] [Problem] In exchanging information between toll gates and ETC vehicles,
An ETC vehicle outside the communication area may receive the radio wave leaking from the communication area, and a non-ETC vehicle within the communication area may be erroneously determined as an ETC vehicle. On the other hand, a method of discriminating a communication area using two antennas has been proposed. However, the communication area obtained as a result of the discrimination is distorted.
There was a risk of misjudgment as a TC car. SOLUTION: By using a beam-formed transmitting antenna and a plurality of beam-formed receiving antennas as a receiving antenna of a roadside device, a received signal from an in-vehicle device is detected by the plurality of receiving antennas and compared, Identify the communication area,
It is now possible to communicate only with ETC vehicles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-stop automatic toll collection system (E) for automatically collecting a toll from a vehicle traveling on a toll road without temporarily stopping the vehicle.
electronic Toll Collection
System: Hereinafter, referred to as an “ETC system”), toll collection is performed between a road machine installed at a tollgate and a vehicle equipped with an on-board unit having an automatic toll collection function (hereinafter, referred to as an “ETC vehicle”). Communication device of a tollgate having a function of determining a communication area when wireless communication is carried out.

[0002]

2. Description of the Related Art Conventionally, on a toll road, a magnetic card type toll collection system has been introduced. This system is described in, for example, Toshiba Review (Vol. 40, No. 3, pp. 1985, pp. 189-192, "Magnetic Card System Toll Collection System") or Mitsubishi Heavy Industries Technical Report VOL. 22
NO. 6 (1985-11), pages 127 to 132, "System Technology in Magnetic Card Type Toll Collection Machine".

[0003] In such a conventional system, when entering a toll road from a general road, or conversely, when exiting from a toll road to a general road, it is absolutely necessary to temporarily stop at a toll gate and obtain a toll ticket. It is necessary to pick up and pay the fee, so that many vehicles are often congested in a line in front of the toll booth. In order to improve such a problem, an ETC system has been proposed which can collect a toll without temporarily stopping at a tollgate.

[0004] Regarding this ETC system, for example,
Mitsubishi Heavy Industries Technical Report VOL. 32 NO. 4 (1995-
7) P264-P267 "Needs and Technical Development in Expressway Traffic Management Systems", NIKKEI BUSI
NESS November 13, 1995 Issue P155-P15
8 "Dispatch of information from roads to cars"
Alternatively, it is described in, for example, Published Japanese Patent Application No. 5-508492, “Electric Vehicle Toll Collection Apparatus and Method,” and specifically described in detail in Published Japanese Patent Application No. 5-508492.

[0005] The ETC system as described above is being jointly developed by the public and private sectors in Japan.
In the article published in the Yomiuri Shimbun (P26-P27 in the morning), 1
It is stated that practical use will be started from 999.

On the other hand, according to Nikkei Mook (published November 6, 1995), "All of ITS", Europe (Germany, Norway, etc., P168-P171), United States (P140-P)
143), Southeast Asia (Malaysia, Singapore, etc. P
In some overseas countries, such as 190-P191), a system as described in the above-mentioned publication is operated.

In this ETC system, it is necessary to transmit and receive information related to toll collection between a vehicle entering the tollgate area and the tollgate using radio waves.
FIG. 19 shows this system, which includes a toll booth 1 for collecting tolls, a passage 2 for vehicles to pass through, a passage separation zone 3 for separating the passage of vehicles, an ETC vehicle 4 entering the passage, and information relating to toll collection. Road machine 5 installed on the tollgate side for transmitting and receiving traffic, support columns 6 for mounting the road machine 5, antenna beam 8 radiated from antenna 7 mounted on the road machine 5, reception area 9 A vehicle sensor 10a, 10b for detecting entry and passage of a vehicle, and a vehicle mounted on the ETC vehicle 4 side for transmitting and receiving information related to toll collection and having an automatic toll collection function comprising an antenna and a transceiver. Machine 11.

Next, the operation will be described. In the communication device of the tollgate configured as described above, the ETC vehicle 4 equipped with the on-vehicle device 11 enters the passage 2 and the vehicle sensor 10
a, it is detected that the ETC vehicle 4 has entered the desired communication area, and when the in-vehicle device 11 is inside the reception area 9, information on the roadside device from the antenna 7 of the roadside device 5, for example, the name of the tollgate , The passing lane and the like are transmitted to the vehicle-mounted device 11.
The in-vehicle device 11 having received this information transmits information on the in-vehicle device, for example, information on the in-vehicle device such as the in-vehicle device number, the vehicle type classification, and the entrance tollgate number to the road device 5. Antenna 7 of road machine 5
The toll booth 1 calculates the toll based on the data on the in-vehicle device received by the
To the vehicle-mounted device 11 as fee information. When it is detected by the vehicle sensor 10b that the ETC vehicle 4 has passed outside the desired communication area, the roadside device 5 and the on-vehicle device 1 are detected.
1 is completed, and non-stop automatic toll collection for the ETC vehicle 4 is completed.

FIG. 20 shows the relationship between the reception area and the communication area. In the ETC system, since the road surface height on which the on-vehicle device 11 is mounted differs depending on a motorcycle, a passenger car, a large vehicle, or the like, the road surface height at which information related to toll collection can be transmitted and received using radio waves is within a certain range (approximately). 1 to 2 m), and the traveling direction in which information can be exchanged is a range sandwiched by the vehicle sensors 10a and 10b. As a result, the desired communication area 12 is defined as a three-dimensional space. Due to the rectilinearity of the radio wave, the antenna beam 8 radiated from the antenna 7 of the on-road unit 5 cannot be suddenly reduced to zero at the point when it exceeds the vehicle sensor 10a.
It is unavoidable that a leaked radio wave area 13 is formed outside the radio wave 2. Also, a toll booth for collecting tolls, a support column 6 for mounting an antenna, and a vehicle sensor 1 for detecting a vehicle.
The leaked radio wave area 13 is also formed by the radio waves 0a and 10b, which are reflected by a metal body such as the ETC car 4 entering the passage 2 and scattered or diffracted out of the desired communication area.

As described above, the inside of the reception area 9 is classified into a desired communication area 12 and a leaked radio wave area 13. For this reason, although the vehicle has not entered the desired communication area 12, communication between the on-board unit 11 mounted on the ETC vehicle 4 and the antenna 7 of the road unit 5 that has entered the leaked radio wave area 13 should not be performed. There may be cases where information related to toll collection is exchanged.

FIG. 21 shows a problem in the case where such a communication area is set. A vehicle without an on-board unit 11 having an automatic toll collection function with a toll booth (hereinafter, referred to as “the toll gate”). A "non-ETC vehicle") 14 enters the desired communication area 12 in advance through the vehicle sensor 10a,
In addition, in a state before passing through the vehicle sensor 10b, the ETC vehicle 4 equipped with the following in-vehicle device 11 enters the area 13 of the leaked radio wave unnecessary for communication, and collects the toll with the antenna 7 of the road device 5. If the related information is exchanged, the leading non-ETC vehicle 14 is regarded as an ETC vehicle and can pass without paying a fee, and the subsequent ETC vehicle 4 re-enters the road when passing the vehicle sensor 10a. Exchange of information related to toll collection with the antenna 7 of the machine 5
As a result, there is a possibility that the error processing will be stopped because the fee is paid twice or the same vehicle passes in a short time.

In order to solve this problem, the 1997 IEICE General Conference, B-2-53, Nakamura, Kuwahara,
A method using direction detection has been proposed in "Development of a position evaluation device for ETC". The position of the in-vehicle device is determined by detecting the phase difference of the received signal using a three-element linear array. The detection method is MUSI
Since the direction of arrival is estimated using the C method, an array of three elements is required in principle to discriminate between two vehicles. Since each element is composed of one element, it has a broad radiation characteristic. Therefore, there is a problem that the accuracy of arrival detection is poor because of the strong influence of surrounding scattered objects such as vehicles and columns. In this example, in order to suppress this phase fluctuation, a calibration signal generator and an SPDT switch are provided, and the phase fluctuation is removed by switching between the received signal and the calibration signal, thereby complicating the system. However, there is a problem that the fluctuation due to the surrounding environment cannot be removed.

[0013] Patent application BP502461 proposes a method using two receiving antennas as shown in FIG. That is, the main system including the main antenna 7a for irradiating the desired communication area 12 and the first receiver 15a, and the desired communication area 12
And a signal processing circuit 16. The signal processing circuit 16 further includes a comparator 17 and a signal processing circuit 16. It comprises a gate 18 and a toll collection control device 19. The main system and the sub system simultaneously receive radio waves 20 from the on-vehicle device 11 to the antennas 7a and 7b of the on-road devices, and compare the respective received powers with the comparator 17, and determine that the received power of the main system is equal to the above. If the received power is larger than that of the sub system, the gate 18 is turned on, and the data received by the main system is transmitted to the toll collection control device 19 in the subsequent stage.
It proposes to communicate and process information related to toll collection by passing through to.

[0014]

As for the method of setting the communication area in this ETC system, in the prior art, as shown in FIG. 23, the reception area 9a of the main antenna 7a and the reception area 9b of the sub-antenna 7b are received. The intersection of the electric power is set as the communication start point, and the vehicle sensor 10b is set as the communication end point. In this case, for example, the communication area 21a when the in-vehicle device 11a mounted on the ETC vehicle 4a passes through the lane center line is a desired area. Although the communication distance is obtained, the communication area 21b when the in-vehicle device 11b mounted on the ETC vehicle 4b passes through the lane end line is longer than the desired communication distance, and the communication area after determination obtained by this method is distorted. As a result, there have been cases where it is regarded as equivalent to radio wave leakage.

Further, in the above-mentioned conventional technique, since the two antennas, the main antenna 7a and the sub-antenna 7b, have a difference in directivity, the amount of fluctuation due to the influence of the surrounding environment such as reflection from a metal body is reduced. There was also a difference, and it was not possible to completely eliminate the influence of the surrounding environment.

The present invention has been made to solve such a problem, and will be described in detail below.

[0017]

In order to solve the above-mentioned problems, a communication device of a tollgate according to the first invention uses a plurality of antennas each having a beam shape formed as a receiving antenna. By comparing received signals, a communication area for exchanging information is specified, and communication is performed only with an ETC vehicle that has entered the communication area.

Further, the communication device at the tollgate according to the second invention uses a plurality of antennas having different beam peak directions and shaped beam shapes, and determines the level of the received signal level of each receiving antenna. A communication area for exchanging information is specified by comparison, and communication is performed only with an ETC vehicle that has entered the communication area.

The communication device of the tollgate according to the third invention uses a plurality of antennas having different beam peak directions and shaped beam shapes, and compares the phase difference of the received signals of the respective receiving antennas. By doing so, a communication area for exchanging information is specified, and communication is performed only with an ETC vehicle that has entered the inside of the communication area.

Further, the communication device of the tollgate according to the fourth invention uses different peak directions of the beams, uses a plurality of antennas, and receives the level difference or the phase difference of the reception amplitude of the reception signal of each reception antenna. By calculating the position of the in-vehicle device or the angle as viewed from the on-road device using both of them, the communication area for exchanging information is specified, and communication is performed only with ETC vehicles that have entered the communication area. It was done.

Further, in the communication device of the tollgate according to the fifth invention, a plurality of antennas having different peak directions of the beams and shaping the beam shapes are used, and a receiver is connected to each of the receiving antennas. Thus, the reception amplitude difference and / or the reception phase difference of a plurality of reception signals are obtained at the same time, thereby enabling high-speed communication with only the ETC vehicle that has entered the communication area.

Further, the communication device of the tollgate according to the sixth invention uses a plurality of antennas each having a different peak direction of a beam and a shaped beam, and receives a signal via a switch for selecting each reception antenna. It is configured by connecting to one receiver.

Further, the communication device of the tollgate according to the seventh invention divides the receiving antenna having a shaped beam into two, and connects a comparator for detecting a sum signal and a difference signal of the two receiving antennas. Mono-pulse detection that detects the position of the onboard unit using the sum signal and the difference signal specifies the communication area for exchanging information and communicates only with ETC vehicles that have entered the communication area. It was done.

Further, the communication device of the tollgate according to the eighth invention is one in which the beam shape of the receiving antenna is shaped into a sector so that the communication area can be received at a substantially constant level.

Further, the communication device of the tollgate according to the ninth invention is one in which the beam shape of the transmitting antenna is shaped into a sector so that the communication area can transmit at a substantially constant level.

The communication device of a tollgate according to a tenth aspect of the present invention provides a transmitting / receiving antenna constituted by an array antenna, and a means for dividing the array antenna into sub-arrays and connecting a means for changing a phase to each sub-array to scan a beam. It is configured to be able to.

Further, the communication device of the tollgate according to the eleventh invention comprises one transmitting antenna and two receiving antennas, sets the peak direction of the beam of the first receiving antenna to a desired communication area, The peak direction of the beam of the second receiving antenna is set outside the desired communication area, the amplitudes of the reception amplitudes of the radio waves received by the two receiving antennas from the vehicle-mounted device are compared, and the reception amplitude intensity of the first receiving antenna is compared. Is larger than the reception amplitude intensity of the second receiving antenna, it is determined that the on-vehicle device is present in the desired communication area, and communication is performed only with the ETC vehicle that has entered the communication area.

Further, the communication device at the tollgate according to the twelfth invention comprises one transmitting antenna having a shaped beam shape and two receiving antennas having a shaped beam shape, and the peak direction of the beam of the transmitting antenna is desired. And the reception amplitudes of the radio waves received from the in-vehicle devices received by the two reception antennas are compared. If the reception amplitude intensity of the first reception antenna is larger than the reception amplitude intensity of the second reception antenna, In addition, it is configured that it is determined that the in-vehicle device is present in the desired communication area, and communication is performed only with the ETC vehicle that has entered the communication area.

Further, the communication device at the tollgate according to the thirteenth invention comprises one transmitting antenna having a shaped beam shape and two receiving antennas having a shaped beam shape, and the peak direction of the beam of the transmitting antenna is desired. Setting the peak direction of the beam of the first receiving antenna within the desired communication region, setting the peak direction of the beam of the second receiving antenna outside the desired communication region, By connecting each receiving antenna to the receiver via the variable attenuator, the two receiving antennas compare the amplitude of the reception amplitude of the radio wave received from the vehicle-mounted device, and the reception amplitude of the first reception antenna becomes When the reception amplitude intensity of the second reception antenna is larger than that of the second reception antenna, the in-vehicle device is determined to be in the desired communication area, and communication is performed only with the ETC vehicle that has entered the communication area. Are those that form.

Further, a communication device of a tollgate according to a fourteenth invention comprises one transmitting antenna having a shaped beam and two receiving antennas having a shaped beam, and each receiving antenna has a variable attenuator. The reception amplitude of the radio wave received from the vehicle-mounted device received by the two reception antennas is compared with each other, and the reception amplitude intensity of the first reception antenna is compared with the reception amplitude intensity of the second reception antenna. If it is larger, it is determined that the in-vehicle device is within the desired communication area, and only when it is determined that the received signal has reached a receivable level, only the ETC vehicle that has entered the communication area is communicated. In which the threshold level is set so as to perform

Further, a communication device of a tollgate according to a fifteenth invention comprises one transmitting antenna having a shaped beam and two receiving antennas having a shaped beam.
Sign of the received signal received by the receiving antenna of
Is added to the reception signal of the second reception antenna whose sign is inverted, and if the result is greater than 0, it is determined that the onboard unit is present in the desired communication area, ETC that has entered the communication area only when it is determined that the
It is configured to communicate only with the car.

The communication device of a tollgate according to a sixteenth aspect of the present invention comprises one transmitting antenna having a shaped beam shape and two receiving antennas having a shaped beam shape. Setting the peak direction of the beam of the first receiving antenna within the desired communication region, setting the peak direction of the beam of the second receiving antenna outside the desired communication region, Second
Is configured such that the beam width of the receiving antenna is smaller than the beam width of the first receiving antenna.

Further, a communication device of a tollgate according to a seventeenth aspect of the present invention comprises a transmitting antenna having a shaped beam shape and a plurality of receiving antennas having a shaped beam formed by a microstrip antenna.

[0034]

FIG. 1 is a view showing a first embodiment of the present invention, in which 1 to 8 and 10a, 10b, and 11 denote the conventional ET.
It is exactly the same as the C system. 9a to 9f are a plurality of reception areas, and 22 is a transmission area. As shown in the figure, one transmitting antenna beam and six receiving antenna beams are used.

Next, the operation will be described. 9 shown in FIG.
Six reception areas a to 9f are set, and 9a to 9d are communicable areas and 9e to 9f are communicable areas. In order to suppress interference with the adjacent lane and interference outside the communication area, the beam of the transmitting antenna is shaped to reduce the side lobe. An ETC vehicle 4 equipped with the on-vehicle device 11 passes through the passage 2,
When the vehicle enters the transmission area 22, information on the roadside machine, for example, the name of a tollgate, a passing lane, etc., is transmitted from the antenna 7 of the roadside machine 5 to the vehicle-mounted device 11. In-vehicle device 1 that has received this information
When the vehicle 1 enters the reception area 9f, the information on the on-vehicle device, for example, the information on the on-vehicle device such as the on-vehicle device number, the vehicle type classification, and the entrance tollgate number is transmitted to the road device 5 when the vehicle enters the reception area 9f. The toll booth 1 calculates a fee based on the data on the on-vehicle device received by the antenna 7 of the on-road device 5 and transmits it again as fee information from the antenna 7 of the on-road device 5 to the on-vehicle device 11. In the communication between the roadside device 5 and the on-vehicle device 11, by setting a plurality of reception areas, the area where the on-vehicle device 11 exists can be determined, and the on-vehicle device 11 existing in a desired area can be determined.
Can only communicate with

For example, as shown in FIG. 1, six reception areas 9a to 9f are set, 9a to 9d are communicable areas, and 9e to 9f are communicable areas. When the in-vehicle device 11 enters the reception area 9f, the received power of the in-vehicle device 11 at the antenna 7 is the largest from 9f among the six areas 9a to 9f set by beam shaping of the reception antenna. 11 is determined to be present at 9f, and since this area cannot be communicated,
Communication between the vehicle and the on-road unit 5 is not performed. Thereafter, when the ETC vehicle 4 further proceeds along the passage 2 and the in-vehicle device enters the reception area 9d, the in-vehicle device 11 in the road device 5
The received power of 6 is set by shaping the receiving antenna.
It is determined that the power from 9d is the largest among the regions 9a to 9f, and the in-vehicle device 11 is located in 9d. Since this region is communicable, the in-vehicle device 11 and the on-road device 5
Communication is performed with the. Thus, by having a plurality of reception areas, the position of the vehicle-mounted device can be determined, and the communication area can be set arbitrarily.

Although FIG. 1 shows the case where the number of the receiving antenna beams is six, if the receiving antenna beam is constituted by a plurality of receiving antenna beams capable of detecting the position of the on-vehicle device, the number of the beams is not limited. The effect remains the same. Although the figure shows an example in which the toll booth has one lane, even if the toll booth has two lanes as shown in FIG. If the lane has the same configuration as that of the present invention, exactly the same effects can be obtained.

Embodiment 2 FIG. 2 is a view showing Embodiment 2 of the present invention, wherein 1 is a toll booth for toll collection, 2 is a passage through which vehicles pass,
Reference numeral 3 denotes a passage separation zone for separating a vehicle passage, reference numeral 4 denotes an ETC vehicle equipped with an in-vehicle device, reference numeral 5 denotes a roadside device installed at a tollgate side for transmitting and receiving information related to toll collection, and reference numeral 6 denotes a roadside device 5. , An antenna mounted on the roadside machine 5, 10 a vehicle sensor arranged at the entrance and exit of the communication area, 9a a vehicle traveling from a sensor 10a installed at the communication area entrance side. The receiving area where the antenna beam 8a is directed toward the front side of the direction, 9b is the main receiving area where the antenna beam 8b is directed substantially at the center of the communication area, and 9c is closer to the vehicle traveling direction than the sensor 10b installed on the exit side of the communication area. Reception area 1 for antenna beam 8c
Reference numeral 1 denotes an in-vehicle device mounted on a vehicle that exchanges information related to toll collection with the on-road device 5, and 22 denotes a transmission area formed by the antenna 7.

FIG. 3 (a) is a side view of the arrangement of the second embodiment, where 5 is a roadside machine, 6 is a support column for mounting the roadside machine 5, and 10a is at the entrance of the communication area. The installed vehicle sensor, 10b is a vehicle sensor arranged at the exit of the communication area, 7 is an antenna mounted on the road machine 5,
7a is a receiving antenna whose antenna beam 8a is directed toward the vehicle traveling direction front side from the sensor 10a installed at the communication area entrance side, 7b is an antenna whose antenna beam 8b is directed substantially at the center of the communication area, and 7c is the communication area exit side 3 is a receiving antenna that directs the antenna beam 8c toward the vehicle traveling direction from the sensor 10b installed in the vehicle, 11 is a vehicle-mounted device, 4 is an ETC vehicle equipped with a vehicle-mounted device, and 3 in FIG.
4 is a roadside machine 5 when the onboard unit 11 passes under the roadside unit 5
34a shows the received power distribution of the on-vehicle device in the receiving antenna 7a.
b is the received power distribution of the onboard unit at the receiving antenna 7b,
Numeral 34c indicates the distribution of the received power of the on-vehicle device at the receiving antenna 7c.

In the communication device of the tollgate configured as shown in FIG. 2, when the vehicle 4 equipped with the vehicle-mounted device 11 passes through the passage 2 and enters the transmission area 22, information on the roadside device from the roadside device 5, For example, the name of a tollgate, a passing lane, and the like are transmitted to the vehicle-mounted device 11. The in-vehicle device 11 having received this information transmits information on the in-vehicle device, for example, information on the in-vehicle device such as the in-vehicle device number, the vehicle type classification, and the entrance tollgate number to the road device 5 when entering the reception area 8. The toll booth 1 calculates the fee based on the data on the in-vehicle device received by the on-road device 5, and transmits the information as toll information from the on-road device 5 to the on-vehicle device 11 again. At this time, the communication area is determined by setting three reception areas as described above and comparing the respective reception powers.

FIGS. 3A and 3B are diagrams for explaining in detail the method of determining the communication area, and show the received power at the three receiving antennas. For example, assuming that the determination condition for the communication area is the reception power 34b at the reception antenna 7b> the reception power 34a at the reception antenna 7a, and the reception power 34b at the reception antenna 7b> the reception power 34c at the reception antenna 7c, the onboard unit detects the sensor 10a If the vehicle is further ahead in the vehicle traveling direction, the received power 34a is greater than the received power 34b, and it is determined that the received power is outside the communication area. When the vehicle-mounted device is located between the sensor 10a and the sensor 10b, the reception power 34b> the reception power 34a, and the reception power 34b> the reception power 34c, and the communication area is determined. When the on-vehicle device is located further in the vehicle traveling direction than the sensor 10b, the received power 34b <the received power 34c, and it is determined that the vehicle is outside the communication area. With this series of operations, the communication area can be easily determined when the vehicle 4 equipped with the in-vehicle device 11 passes through the lane.

Third Embodiment FIG. 4A is a diagram showing a third embodiment of the present invention.
5 is a roadside machine, 6 is a support column for mounting the roadside machine 5, 7 is an antenna mounted on the roadside machine 5, 11 is a vehicle-mounted device, 36a is a propagation path from the antenna 7a to the vehicle-mounted device 11, and 36b is mounted on the antenna 7b. Propagation path from the antenna 7c to the vehicle-mounted device 11;
FIG. 4B shows a device to be mounted on the on-road unit 5, 7 denotes an antenna, and 23 denotes an antenna 7.
a, 7b, 7c, a phase detector for detecting the phase of the received radio wave; and 16, a signal processing circuit for processing the phase signal detected by the phase detector.

Next, the operation principle will be described. In-vehicle device 1
When the vehicle 4 carrying the vehicle 1 passes through the passage 2 and comes to an area where signals can be received by the on-road unit, the receiving antennas 7a, 7b,
At 7c, a signal from the vehicle-mounted device is received and the phase is detected. At this time, as shown in FIG. 4, the propagation distance from the in-vehicle device to the receiving antenna is different, so that a phase difference occurs. The phase difference is detected and processed by the signal processing circuit to detect the position of the vehicle-mounted device, and the communication area can be easily determined using the position information.

Fourth Embodiment FIG. 5 is a diagram showing a fourth embodiment of the present invention.
In (a), 34a, 34b, and 34c indicate the reception power of the signal received by each receiving antenna. In FIG. 5B, reference numerals 35a, 35b, and 35c indicate phases of signals received by the respective receiving antennas.

Next, the operation principle will be described. 34a,
The receiving beams 34b and 34c form beams so as to intersect at the end of the communication area. That is, the level of the reception beam 34b is high in the communication area, and the reception beam 34a is outside the communication area in front of the vehicle as viewed from the traveling direction of the vehicle.
Is out of the rear communication area, the power of the reception beam 34c is high. Therefore, as described in the second embodiment, the communication area can be determined by comparing the received power. Further, in the present invention, the position of the vehicle is detected by calculating the difference between the reception levels. 34b >> 3
If it is 4a, the vehicle is far from the communication area, and 34b ≒ 34
If it is a, it is understood that it is almost the end of the communication area. Further, if the reception powers of the main antenna and the sub antenna are grasped in advance, the position of the vehicle can be detected from the difference between the reception powers. FIG. 5B shows the phase difference of the received power. If the phase difference between the received signals of the main antenna and the sub-antenna is grasped in advance in the same manner as in FIG. 5A, the position of the vehicle-mounted device can be detected by processing with the signal processing circuit.

Fifth Embodiment FIG. 6 is a view showing a fifth embodiment of the present invention, in which 7 is a receiving antenna mounted in the on-road unit 5, 15a, 15b,
Reference numeral 15c denotes a plurality of receivers connected to each receiving antenna for detecting the amplitude and phase, and 16 denotes a signal processing circuit for calculating a position from the amplitude and phase data detected by the receiver.

Next, the operation principle will be described. When the in-vehicle device enters the vicinity of the communication area, radio waves from the in-vehicle device are received by a plurality of receiving antennas 7 having different beam center directions. The amplitude and / or phase of the received radio waves are simultaneously detected by a receiver 15 connected to each of the receiving antennas 7, and the information of the amplitude and / or phase of the plurality of signals is transmitted to a signal processing circuit. 16
, The position of the in-vehicle device can be instantaneously detected and the communication area can be determined.

Sixth Embodiment FIG. 7 is a view showing a sixth embodiment of the present invention, in which 7 is a receiving antenna mounted on the roadside device 5, 24 is a beam switching switch for switching each receiving antenna, 15a and 15
Reference numerals b and 15c denote a single receiver connected to each receiving antenna for detecting an amplitude, and reference numeral 16 denotes a signal processing circuit for calculating a position from phase data detected by the receiver.

Next, the operation principle will be described. When the in-vehicle device enters the vicinity of the communication area, radio waves from the in-vehicle device are received by a plurality of receiving antennas 7 having different beam center directions. At this time, the receiving antenna 7 for receiving the radio wave is selected by switching the beam switch 24, only the radio wave received by the selected receiving antenna 7 is passed to the receiver 15, and the amplitude or phase of the radio wave or the Detect both. This switching operation is repeated to detect the amplitude and / or phase of the radio waves received by the plurality of receiving antennas, and to process the information of the amplitude and / or phase of the plurality of signals by the signal processing circuit 16. Thereby, the position of the vehicle-mounted device can be detected, and the communication area can be determined.

Seventh Embodiment FIG. 8 is a diagram showing a seventh embodiment of the present invention.
FIG. 8A is a block diagram thereof, and FIG. 8B shows a relationship between an error voltage and an angle by a monopulse comparator. Reference numeral 7 denotes a receiving antenna, and reference numeral 25 denotes a monopulse comparator that generates a Σ component that combines the sum of the powers of the received signals received by the two receiving antennas and a Δ component that combines the difference signal between the two powers. 15a and 15b are receivers connected to the monopulse comparator, 16 is the Σ component detected by the receiver and Δ
This is a signal processing circuit that detects the position of the vehicle-mounted device from the components.

Next, the operation principle will be described. When the in-vehicle device enters the vicinity of the communication area, a radio wave from the in-vehicle device is received by the receiving antenna 7, a パ ル ス component and a Δ component are generated by the monopulse comparator 25, and the voltage is detected by the receiver 15. Here, a graph of an S-shaped curve showing the relationship between the error voltage and the angle as shown in FIG. 8B is stored in the signal processing circuit in advance, and is created from the two components detected by the receiver. By extracting angle information from the error voltage, the position of the vehicle-mounted device is easily detected, and the communication area is determined.

Eighth Embodiment FIG. 9 is a view showing an eighth embodiment of the present invention, wherein 1 to 8 and 10a, 10b, 11 denote the conventional ET.
It is exactly the same as the C system. 9a, 9b,
9c is a reception beam obtained by shaping the beam.

Next, the operation principle will be described. When a beam is normally formed, the beam shape becomes a pencil-shaped beam. Since the cross-sectional shape of the pencil-shaped beam is elliptical, the ellipse covers the communication area. On the other hand, since the communication area is defined by a rectangular area, the communication area and the beam shape do not match. Furthermore, since the beams are crossed to determine the inside and outside of the communication area, the crossed area is linear in the width direction of the road. However, even if the elliptical beams cross, they do not form a linear boundary. If it is not straight, there is a problem that the boundary area between the center and the edge of the road changes. Therefore, a sector beam is formed so that the beam shape in the road width direction becomes linear. By combining the sector-shaped beams, the communication boundary region where the beams intersect can be made linear, and the boundary can be clarified. Also,
With such a beam shape, fluctuations in the reception level in the communication area can be reduced.

Ninth Embodiment FIG. 10 is a view showing a ninth embodiment of the present invention, wherein 1 to 8 and 10a, 10b, and 11 denote the conventional E.
Exactly the same as the TC system, 9a, 9
b and 9c are reception beams obtained by shaping beams, and 22 is a transmission beam obtained by shaping beams.

Next, the operation principle will be described. Embodiment 8 shows an example in which the reception antenna beam is shaped into a sector, but the present invention further shows that the transmission beam is shaped into a sector. Basically, the communication area is determined from the reception level. If the transmission beam is elliptical, the radiation to the outside of the communication area is different at the center and the end of the road, so that an error in the communication area is likely to occur. Therefore, the error can be minimized by making the transmission beam sector-shaped. Further, since the radiation outside the communication area can be reduced, the boundary can be further clarified, and the radiation level into the communication area can be made uniform.

Tenth Embodiment FIG. 11 is a diagram showing a tenth embodiment of the present invention.
Reference numerals a to 7i denote reception antennas, and reference numerals 26a, 26b, and 26c denote phase shifters that change the phase amount of each element antenna or subarray.

Next, the operation principle will be described. The phase shifters are connected to the receiving antennas 7a to 7i. This phase shifter may be connected to each receiving antenna, or several receiving antennas may be combined into a sub-array and connected to the sub-array. By changing the phase of the phase shifter, the direction of the beam can be changed, and the beam can be scanned. Since the beam is electronically scanned, the beam can be freely scanned into and out of the communication area, and the position of the vehicle can be detected. At this time, the beam is scanned into and out of the communication area, but in order to further clarify the communication area,
It is desirable to shape the beam into a sector. The sectoring improves the accuracy of detecting the vehicle position.

Embodiment 11 FIG. 12 is a view showing an embodiment 11 of the present invention. In FIG. 12 (a), 2 is a passage through which a vehicle passes, 5 is a road machine, 7 is a receiving antenna, 9a and 9b. Is the reception area, 22
Is a transmission area, 11 is an in-vehicle device, 4 is an ETC vehicle equipped with the in-vehicle device 11, and 10b is a sensor for detecting that the ETC vehicle 11 has passed through the communication area. FIG. 12 (b)
In the figure, 34a indicates the received power distribution of the signal received by the sub antenna, 34b indicates the received power distribution of the signal received by the main antenna, and 21 indicates a desired communication area.

Next, the operation principle will be described. In-vehicle device 1
When the ETC vehicle 4 equipped with No. 1 enters the passage 2 and enters the transmission area 22, a radio wave carrying information is transmitted from the on-road machine,
The in-vehicle device 11 having received the radio wave transmits a radio wave carrying information to the on-road device. Here, the receiving antenna 7 installed in the on-road unit is a receiving area 9 of the main antenna.
b and the receiving area of the sub-antenna. The distribution of the received power of the signals received by these two receiving antennas is shown in FIG.
If the intersection of these two distributions is set at the entrance of the desired communication area 21 as shown in (b), the on-vehicle equipment is present in the communication area by receiving the radio wave from the on-vehicle equipment. It is possible to determine whether or not to perform. In addition, whether the in-vehicle device has exited the communication area is determined by installing the sensor 10b at the exit of the communication area, and determining that the in-vehicle device has passed the communication area when the head of the vehicle has cut off the sensor. It is possible to reduce the number of sub receiving antennas for detecting the terminating part. Also, by using the receiving antenna sector-shaped beam, the boundary of the communication area can be clarified.

Twelfth Embodiment FIG. 13 is a view showing a twelfth embodiment of the present invention. In FIG. 13, reference numeral 2 denotes a passage through which a vehicle passes;
Is a reception antenna, 9a and 9b are reception areas, 22 is a transmission area, 11 is a vehicle-mounted device, and 4 is an ET on which the vehicle-mounted device 11 is mounted.
The C car and 10b are sensors for detecting that the ETC car 11 has passed through the communication area.

Next, the principle of operation will be described. In the present invention, the operation is the same as that of the twelfth embodiment, but by forming the transmission antenna beam and making the transmission area 22 the same as the communication area or the main reception area 9b,
The discrimination accuracy at the entrance of the communication area is improved.

Thirteenth Embodiment FIG. 14 is a diagram showing a thirteenth embodiment of the present invention, wherein a signal from a vehicle-mounted device is received by a main antenna 7a and a sub-antenna 7b, respectively, and a received signal A and a received signal are received. B
1 is a block diagram showing a receiving system according to the present invention, in which a communication area is determined by comparing .times. In the figure, reference numeral 27 denotes a variable attenuator. The signal from the onboard unit is 2
The signal received by the main antenna 7a is processed as a received signal A via the receiver A, while the signal received by the sub antenna 7b is received via the receiver B. The signal B is processed as a signal B, the two signals are compared by a comparator, and the gate 18 is turned ON only when the received signal A is large, thereby transmitting the received signal A to the toll collection control device 19 at the subsequent stage. Only when it is determined that the data relating to toll collection is exchanged.

Fourteenth Embodiment FIG. 15 is a diagram showing a fourteenth embodiment of the present invention, in which a signal from a vehicle-mounted device is received by a main receiving antenna 7a and a sub receiving antenna 7b, respectively, FIG. 2 is a block diagram of a receiving system that determines a communication area by comparing received signals B and extracts only received signals A; The signal from the onboard unit is received by two antennas, but the signal received by the main antenna 7a is processed as a received signal A via the receiver A, while the signal received by the sub antenna 7b is received The received signal B is processed as a received signal B via the device B, the two signals are compared by a comparator, and only when the received signal A is large, the gate 18a is turned on to send the received signal A to the subsequent stage. A is compared with a certain threshold level, the gate 18b is turned ON only when the threshold level exceeds the reception signal A, and the reception signal A is sent to the toll collection control device 19 at the subsequent stage. Data regarding toll collection is exchanged.

Embodiment 15 FIG. 16 shows that a signal from a vehicle-mounted device is received by a main antenna 7a and a sub-antenna 7b, respectively, and a received signal A and a received signal B are compared to determine a communication area. It is a block diagram which extracts only the signal A. In the figure, 28
Is a sign inverter, and 29 is an adder. The signal from the onboard unit is received by two antennas, but the main antenna 7
The signal received at a is processed as a received signal A via the receiver A, while the signal received at the sub-antenna 7b passes through the receiver B, and is sign-inverted at the subsequent stage to become a received signal -B. The adder adds the received signal A and the received signal -B to obtain a received signal AB, which is compared with the 0 level by the comparator. The gate 18 is turned on only when the received signal AB is larger than 0. When the signal is turned on, the received signal A is sent to the toll collection controller 19 at the subsequent stage, so that data relating to toll collection is exchanged only when it is determined that the communication area is set. Thus, data can be transmitted and received only when the in-vehicle device is in the communication area determined by the two antennas.

Sixteenth Embodiment FIG. 17 is a diagram showing a sixteenth embodiment of the present invention. In FIG. 17A, reference numeral 9a denotes a reception area of a sub antenna.
FIG. 17 (b) shows the distribution of received power at each antenna. The received power distribution 34b at the main antenna and the received power distribution 34a at the sub antenna intersect near the entrance of the communication area 21. It has been set. In the present invention, in order to increase the accuracy of the determination of the communication area, the sub-antenna beam width is narrowed, and the inclination 34b of the received power distribution at the sub-antenna is set to the value shown in FIG.
The inclination is larger than the inclination shown in FIG.

Seventeenth Embodiment FIG. 18 shows a seventeenth embodiment of the present invention.
0 is a ground conductor, 31 is a dielectric substrate, 32 is a microstrip line, and 33 is a radiating element. By using a microstrip antenna, miniaturization, weight reduction, and cost reduction can be achieved.

[0067]

According to the first aspect of the present invention, there is an effect that a communication area can be determined by using a plurality of shaped beams.

Further, according to the second aspect, there is an effect that the communication area can be easily determined only by comparing the reception amplitudes of a plurality of shaped beams.

Further, according to the third aspect, there is an effect that the communication area can be easily determined only by comparing the reception phases of a plurality of shaped beams.

Further, according to the fourth aspect, there is an effect that the position of the vehicle-mounted device can be accurately detected by comparing the reception signals of a plurality of shaped beams.

According to the fifth aspect of the present invention, the reception signals of a plurality of shaped beams can be compared at the same time, so that there is an effect that the time for data transmission and reception can be reduced.

According to the sixth aspect of the present invention, since one receiver can be configured, there is an effect that cost can be reduced.

Further, according to the seventh aspect, the use of the monopulse method has an effect that the position of the vehicle-mounted device can be detected with a simple configuration.

According to the eighth aspect, by dividing the beam into sectors, the boundary of the communication area can be made substantially linear, and the communication distance between the center of the lane and the end of the lane can be made substantially equal. .

Further, according to the ninth aspect, by making the transmission beam and the reception beam the same in the communication area, there is an effect of improving the accuracy of the communication area.

According to the tenth aspect, by scanning the beam using the phase shifter, there is an effect that the position of the vehicle-mounted device can be accurately detected.

According to the eleventh aspect, by dividing the beam into sectors, the boundary of the communication area can be obtained with high accuracy, and the use of two receiving antennas has the effect of reducing the size of the on-road unit. is there.

According to the twelfth aspect, by making the beam directions of the transmitting antenna and the receiving antenna the same,
This has the effect of reducing radio waves leaking out of the communication area and improving the accuracy of the communication area.

According to the thirteenth aspect, the reception level can be adjusted by interposing the variable attenuator between the receiving antenna and the receiver, and the influence of the individual difference of the receiving antenna or the receiver and the installation location can be adjusted. There is an effect that the influence of the environment can be corrected.

Further, according to the fourteenth aspect, by setting an appropriate threshold level for a received signal, the communication area can be set accurately.

According to the fifteenth aspect, the signal processing circuit is composed of the sign inverter and the adder, so that the processing can be easily performed.

According to the sixteenth aspect, the beam width of the second receiving antenna is narrower than the beam width of the first receiving antenna, thereby increasing the gradient of the difference between the first and second reception levels. This has the effect of improving the accuracy of determining the communication area.

Further, according to the seventeenth aspect, the use of the microstrip antenna can reduce the size, weight, and thickness of the on-road unit, thereby providing an advantageous effect of making the configuration suitable for mass production.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an ETC system showing a first embodiment of a communication device of a tollgate according to the present invention.

FIG. 2 is a schematic configuration diagram of an ETC system showing a second embodiment of a communication device of a tollgate according to the present invention.

FIG. 3 is a diagram showing a method of determining a communication area in a tollgate communication device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a method of determining a communication area in a tollgate communication device according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a method of determining a communication area in a tollgate communication device according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram of a receiving system showing a fifth embodiment of a communication device at a tollgate according to the present invention.

FIG. 7 is a block diagram of a receiving system showing a communication apparatus of a tollgate according to a sixth embodiment of the present invention.

FIG. 8 is a block diagram of a receiving system showing a communication device of a tollgate according to a seventh embodiment of the present invention.

FIG. 9 is a schematic configuration diagram of an ETC system showing an embodiment 8 of a tollgate communication device according to the present invention.

FIG. 10 is a schematic configuration diagram of an ETC system showing a ninth embodiment of a tollgate communication device according to the present invention.

FIG. 11 is a block diagram of a receiving system showing Embodiment 10 of a communication device at a tollgate according to the present invention.

FIG. 12 is a schematic configuration diagram of an ETC system showing an embodiment 11 of a tollgate communication device according to the present invention.

FIG. 13 is a schematic configuration diagram of an ETC system showing a twelfth embodiment of a tollgate communication device according to the present invention.

FIG. 14 is a block diagram of a receiving system showing a thirteenth embodiment of a communication device of a tollgate according to the present invention.

FIG. 15 is a block diagram showing the configuration of a receiving system according to a fourteenth embodiment of the communication device at the tollgate according to the present invention.

FIG. 16 is a block diagram of a receiving system showing Embodiment 15 of the communication device at the tollgate according to the present invention.

FIG. 17 is a schematic configuration diagram of an ETC system showing a sixteenth embodiment of a tollgate communication device according to the present invention.

FIG. 18 is a schematic configuration diagram of a microstrip antenna showing a seventeenth embodiment of a tollgate communication device according to the present invention.

FIG. 19 is a schematic configuration diagram showing a device configuration in an ETC system.

FIG. 20 is a diagram illustrating setting of a communication area by a conventional method using one antenna in the ETC system.

FIG. 21 is a diagram illustrating a phenomenon that causes a problem when a communication area is set by a conventional method using one antenna in an ETC system.

FIG. 22 is a block diagram illustrating a configuration of a receiving system when a communication area is set by a conventional method using two antennas in an ETC system.

FIG. 23 is a diagram illustrating a communication area and a problem when a communication area is set by a conventional method using two antennas in the ETC system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Toll booth 2 Passage 3 Passage separation zone 4 ETC car 5 Roadside machine 6 Support pole 7 Antenna 8 Antenna beam 9 Reception area 10 Vehicle sensor 11 In-vehicle equipment 12 Desired communication area 13 Leakage radio wave area 14 Non-ETC car 15 Receiver Reference Signs List 16 signal processing circuit 17 comparator 18 gate 19 toll collection control device 20 radio wave from onboard unit to road unit 21 communication area 22 transmission area 23 phase detector 24 beam switch 25 monopulse comparator 26 phase shifter 27 variable attenuator 28 code Inverter 29 Adder 30 Ground conductor 31 Dielectric substrate 32 Microstrip line 33 Radiating element 34 Received power distribution 35 Received phase distribution 36 Propagation path

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code FI H04Q 7/36 H04B 7/26 105A (72) Inventor Yoshiaki Tsuda 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation In company

Claims (17)

[Claims] 1. A communication device for a tollgate in a non-stop automatic toll collection system, comprising: a single communication device having a beam shape shaped to suppress interference with an adjacent lane or interference outside a communication area in the communication device. A transmitting antenna, a plurality of receiving antennas having a beam shape shaped to suppress interference with an adjacent lane and interference outside the communication area, a receiver connected to the receiving antenna, and the plurality of receiving antennas The reception area corresponding to each antenna is set to be communicable or uncommunicable, and the reception area where the in-vehicle device is present is specified by comparing a plurality of reception signals received by the receiver with each other, thereby defining the communication area. A communication device for a tollgate, comprising: a signal processing device for determining. 2. A plurality of receiving antennas in a communication device at a tollgate have different peak directions of antenna beams, and a receiver detects the amplitude of a received signal, and a signal processing device detects the amplitude of each signal. 2. The communication device according to claim 1, wherein the difference is detected. 3. A plurality of receiving antennas in a communication device at a tollgate have different peak directions of antenna beams, and a receiver detects a phase of a received signal, and a signal processing device detects a position of each signal. 2. The communication device according to claim 1, wherein a phase difference is detected. 4. A plurality of receiving antennas in a communication device at a tollgate have different peak directions of antenna beams, and a receiver detects an amplitude and a phase of a received signal. 2. The communication device according to claim 1, wherein an amplitude difference and a phase difference are detected. 5. A plurality of receiving antennas in a communication device at a tollgate, each of which has a different peak direction of an antenna beam, and the receiver detects the amplitude and / or phase of a received signal at the same time. 2. The communication device according to claim 1, wherein an amplitude difference and a phase difference of each signal are detected. 6. A communication device in a tollgate, wherein a switch for switching each of the receiving antennas is provided between the plurality of receiving antennas and the receiver.
The communication device of the tollgate according to any one of the above. 7. A receiving antenna in a communication device at a tollgate, the receiving antenna is divided into two, a comparator for detecting a sum and a difference signal of the two receiving antennas is provided, and monopulse detection is performed by the comparator. The communication device of a tollgate according to claim 1, wherein: 8. The communication apparatus according to claim 1, wherein the plurality of receiving antennas in the communication device at the toll booth are shaped into a sector shape so that the reception area can be received at a substantially constant level. Communication device of the toll booth according to any of the above. 9. A transmission antenna in a communication device at a tollgate, wherein a beam shape is formed into a sector shape so as to transmit at a substantially constant level in a transmission area. Toll booth communication equipment. 10. A transmitting antenna and a receiving antenna in a communication device at a tollgate are configured as an array antenna in which a plurality of element antennas are arranged, and each element antenna or several element antennas constituting the array antenna are grouped. 2. A communication device according to claim 1, wherein said sub-array is provided with means for changing the phase, and the means scans the beam of the transmitting / receiving antenna. 11. A transmitting antenna and a plurality of receiving antennas in a communication device at a tollgate include a single transmitting antenna having a sector-shaped beam shape and two receiving antennas having a sector-shaped beam shape. The first receiving antenna sets the peak direction of the beam within the communication area, the peak direction of the beam of the second receiving antenna is set outside the communication area, and the received power of the first receiving antenna is set to the second power. 2. The communication device according to claim 1, wherein communication is performed only when the received power is larger than the received power. 12. The toll booth according to claim 11, wherein the transmitting antenna of the communication device at the toll booth has the same beam peak direction as that of the first receiving antenna. Communication device. 13. A communication device in a tollgate, wherein a variable attenuator capable of arbitrarily varying the power of a received signal is inserted between a receiving antenna and a receiver, and the power received by the first receiving antenna or the 13. The tollgate communication device according to claim 12, wherein the power received by the two receiving antennas or both of them can be adjusted. 14. A communication device at a tollgate is provided with a variable attenuator capable of arbitrarily varying the power of a received signal between a receiving antenna and a receiver, and a unit capable of setting a certain reference power in a signal processing device. Adjusting the power received by one of the receiving antennas and / or the power received by the second receiving antenna, comparing the received signal received by the first receiving antenna with reference power, and thereby communicating 2. An area is determined.
2. The communication device of the tollgate according to 2. 15. A signal processing device in a communication device at a tollgate, means for inverting a sign of a received signal received by the second receiving antenna, a signal inverted by the sign and a received signal received by the first receiving antenna. And means for adding
13. The communication device according to claim 12, wherein communication is performed only when the result of the addition is greater than zero. 16. The two receiving antennas in the communication device at the tollgate set the peak direction of the beam of the first receiving antenna in a desired communication area and set the peak direction of the beam of the second receiving antenna. The toll booth according to any one of claims 11 to 15, wherein the toll gate is set outside the communication area, and the beam width of the second receiving antenna is smaller than the beam width of the first receiving antenna. Communication device. 17. A transmission antenna and a plurality of reception antennas in a communication device at a tollgate, wherein: a ground conductor, a dielectric substrate provided on the ground conductor, a feed line provided on the dielectric substrate, 17. A toll booth according to any one of claims 1 to 16, characterized in that the toll booth is configured by a mat cross-strip antenna that is provided on the same plane and that is connected to the feeder line and is connected to a radiating element to be fed. Communication device.