JP2003296775A - On-vehicle etc equipment and method for communication control thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely complete the communication of information of collecting a toll by removing wasteful communication operation repeated because of a communication error based on a variation in reception electric field in an on- vehicle ETC (electronic toll collection) equipment. <P>SOLUTION: The on-vehicle ETC equipment is provided with a CPU part which reads the reception electric field of an FCMC signal transmitted from a load side antenna via a communication control part and compares the read reception electric field with a threshold of communication start and that of communication stoppage. The CPU part judges whether the reception electric field exceeds the threshold of communication start (step S17). When exceeding the threshold of communication start, the CPU transits the communication state of the on-vehicle ETC equipment to a presently communicating state (step S18). When not exceeding the threshold of communication start (YES at a step S5) and when reception electric field becomes lower than the threshold of communication start after exceeding the threshold of communication start (step S14), the CPU transits the communication state to a presently stopping state (step S15) to avoid the occurrence of the communication error. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ETC vehicle-mounted device used in an automatic toll collection (ETC) system for collecting tolls wirelessly on a toll road such as an expressway and its communication control. Regarding the method.

[0002]

2. Description of the Related Art In recent years, on toll roads such as highways,
The ETC system is being introduced to alleviate and alleviate traffic congestion near toll gates.

This ETC system is equipped with an ETC vehicle-mounted device, which has a wireless communication function and is detachably provided with an IC card storing user-specific information, etc.
Wireless communication is performed between the TC vehicle-mounted device and a roadside device including a lane control device provided at a gate of a toll gate such as a toll road, and the toll of the vehicle is electronically collected.

Therefore, an outline of the ETC system 1 will be described with reference to FIG. Here, a case where the ETC system 1 called “two-antenna method” is applied to a gate at an entrance toll gate will be described as an example. The rules in the following description are basically based on the toll road automatic toll collection system standard (ARIB STD-T55) of the Association of Radio Industries and Businesses (ARIB).

The ETC system 1 includes a first vehicle detector 14 for detecting a vehicle 12 equipped with an ETC vehicle-mounted device 10 entering a gate and a break with a following vehicle (not shown), and the vehicle 12 described above. Vehicle length detector 1 for detecting vehicle length
6 and a vehicle height detector 18 for detecting the vehicle height of the vehicle 12.
And an axle detector 2 that is embedded in the road surface and detects the number of axles of the vehicle 12 based on the number of times the tire of the vehicle 12 is pressed.
It has a vehicle type discriminating unit 22 composed of 0 and 0.

When the vehicle information of the vehicle 12 is introduced from the vehicle type discriminating unit 22, wireless communication is started via the first roadside antenna 24 and the entrance to the ETC vehicle-mounted device 10 mounted on the vehicle 12 is started. Send the toll gate information such as the toll gate number and the date and time when you entered the gate of the toll gate, then ETC
It has a lane control device 26 that receives vehicle information such as an ID (identification) number of the ETC vehicle-mounted device 10 and a registration number of the vehicle 12 from the vehicle-mounted device 10.

Further, after detecting that the vehicle 12 has passed through the first communication zone 28 of the first roadside antenna 24, the second detection information is derived to the lane control device 26.
The vehicle detector 30 is provided, and the communication with the first roadside antenna 24 is normally completed, and the vehicle 12 has the third vehicle detector 3
2 is detected by the ETC vehicle-mounted device 1 mounted on the vehicle 12 based on a command from the lane control device 26.
0 and the second communication zone 34, for example, the settlement information such as the credit card number of the user and the account number of the financial institution is received from the ETC vehicle-mounted device 10, and then the vehicle type determination unit 2
It has a second roadside antenna 36 for transmitting the vehicle information of the vehicle 12 detected by 2 and charging information such as a toll to the ETC vehicle-mounted device 10.

Furthermore, the ETC system 1 has a roadside display 38 for displaying a stop or start instruction to the vehicle 12 and specific information from a tollgate office (not shown), and a voice charge. The vehicle has an intercom 40 for communicating with the office, a start controller 44 for instructing whether to start the vehicle 12 by opening and closing a blocking rod 42, and the vehicle 12 has a second roadside antenna 36. After detecting that the vehicle has passed through the second communication zone 34, the fourth vehicle detector 46 that derives the detection information to the lane control device 26.

The ETC system 1 configured as described above
In, the ETC vehicle-mounted device 10 mounted on the vehicle 12,
Communication information with the lane control device 26 via the first roadside antenna 24 and the second roadside antenna 36 is transmitted to a host computer (not shown) in the ETC operation management center via the tollgate office. Therefore, the toll of the vehicle 12 is settled with the credit card company or the financial institution with which the user has a contract.

In the ETC system 1 described above, when the vehicle 12 equipped with the ETC vehicle-mounted device 10 enters the lane at the gate of the entrance toll gate, the vehicle type discrimination unit 22
Based on the detection signal of the FCMC from the lane control device 26 via the first roadside antenna 24 as a prescribed polling signal.
The (frame control message channel) signal is transmitted. On the ETC vehicle-mounted device 10 side, after receiving the FCMC signal, the operation flowchart shown in FIG. 5 is started.

First, step S21 for frequency selection is executed. Here, in order to tune to the communication frequency used for the first roadside antenna 24, a scanning operation of the communication frequency is performed. By this scanning operation, the communication frequency of the first roadside antenna 24 is detected and selected, and the operations of steps S21 and S22 are repeatedly executed until the selection is completed in step S22. As the communication frequency, a prescribed frequency is stored in the ETC vehicle-mounted device 10 in advance.

When the communication frequency with the first roadside antenna 24 is selected, subsequently, in the ETC vehicle-mounted device 10, the lane controller 26 sends the first roadside antenna 24 for initial connection.
It is determined whether or not a request to send an ACTC (Activation channel: Start communication of vehicle-mounted device) signal is received via (step S23).

When the request to transmit the ACTC signal is not received {NO (No) in step S23}, the lane control device 26 side has not started the communication operation, and the ETC vehicle-mounted device 10 is set to the first 1 roadside antenna 24
The vehicle is not initially connected to the lane control device 26 via the. Therefore, as the subsequent ETC transaction, steps S24, S25 and S26 for exchanging the information of fee collection are all NO, and the operation for communicating on the ETC vehicle-mounted device 10 side is returned to step S23.

On the other hand, when the transmission request for the ACTC signal is received {YES in step S23}, ETC
The ACTC signal is transmitted from the vehicle-mounted device 10 (step S
27). When the ACTC signal is accepted by the lane control device 26, a connection confirmation signal is returned and the ETC vehicle-mounted device 10
Is initially connected to the lane control device 26 via the first roadside antenna 24.

Next, in order to exchange the fee collection information as an ETC transaction, first, the ETC vehicle-mounted device 10 receives an MDC (message data channel) for transmitting the communication information (communication data) including the fee collection information. It is determined whether it has been done (step S24). When this MDC signal is not received (NO in step S24), the operation for communicating proceeds to step S25.

On the other hand, when the MDC signal is received (YES in step S24), the ETC vehicle-mounted device 10 determines the MDC signal.
Signal reception processing is performed (step S28).

Subsequently, it is determined whether or not there is an MDC signal to be transmitted from the ETC vehicle-mounted device 10 to the lane control device 26 (step S25). When there is no MDC signal to be transmitted (NO in step S25), the process proceeds to step S26,
On the other hand, when there is an MDC signal to be transmitted (step S25
YES), the ETC vehicle-mounted device 10 performs a transmission process of the MDC signal (step S29).

Next, an ACK for notifying whether or not the MDC signal in the lane control device 26 is normally received.
It is determined whether or not the C (AC channel: confirmation response channel) signal is received (step S26).
When this ACKC signal is not received (step S
26), the lane control device 26 side considers that communication of the MDC signal is not completed, etc.
The operation for communicating on the C vehicle-mounted device 10 side is step S23.
Returned to.

On the other hand, when the transmission of the MDC signal is normally completed, the ETC vehicle-mounted device 10 causes the lane control device 26 to perform the first operation.
The ACKC signal is received via the roadside antenna 24 (YES in step S26), and the reception process of the ACKC signal is performed (step S30). Then, the operation for communication on the ETC vehicle-mounted device 10 side is completed.

The communication with the lane control device 26 via the second roadside antenna 36 is carried out by the first roadside antenna 2 described above.
As in the case of communication via 4, the steps S21 to
It is executed based on S30.

Further, the information about the fee collection received as the ETC transaction is, for example, the lane control device 2
The information transmitted from 6 includes toll gate information such as the entrance toll gate number and the date and time when the vehicle 12 equipped with the ETC vehicle-mounted device 10 entered, and the vehicle type identification unit 2
The vehicle information of the vehicle 12 detected by 2 and charging information such as a toll. On the other hand, the information transmitted from the ETC vehicle-mounted device 10 includes the ID number of the ETC vehicle-mounted device 10 and the vehicle 12
Vehicle information such as the registration number, and settlement information such as the credit card number of the user and the account number of the financial institution.

Then, in the ETC vehicle-mounted device 10, the toll gate information, vehicle information, billing information and the like received from the lane control device 26 are written in the IC card, and the operation on the ETC vehicle-mounted device 10 side is completed.

[0023]

Here, in the ETC vehicle-mounted device 10, for example, after the vehicle 12 has entered the lane,
In order to communicate via the first roadside antenna 24, the steps S21 and S22 of frequency selection are executed and it is detected whether or not a sufficient reception electric field is obtained. That is, the ETC vehicle-mounted device 10 uses the reception electric field of the FCMC signal, detects that the reception electric field exceeds the specified threshold value (-60.5 dBm) for starting communication,
The operation for communicating is started.

However, as shown in FIG.
The TC vehicle-mounted device 10 detects the threshold value for starting the communication (see FIG. 4).
(Point A in the figure), even if the operation to communicate is started,
For example, there are cases where a sufficient reception electric field cannot be obtained depending on the influence of reflection in the surroundings and the radio condition (between points A and B in FIG. 4). That is, in the communication via the first roadside antenna 24, when the communication threshold value (-65.5 dBm) defined on the lane control device 26 side is exceeded, the communication operation on the lane control device 26 side is performed. There is a problem that it is stopped and a communication error occurs.

In this case, in the ETC vehicle-mounted device 10, for example, in steps S23 and S27 relating to the transmission of the ACTC signal for initial connection, this operation is repeatedly executed 100 times or more to try to complete the initial connection again. . If the initial connection is not completed during this period, the operation for communicating is returned to step S21 for frequency selection.

In step S27, the ACT
After the C signal is transmitted, steps S24 and S28 relating to the reception of the MDC signal as the ETC transaction.
In this case, this operation is also repeated 100 times or more in the same manner as described above, and when reception processing is not performed during this operation, the operation for communication is the same as the above-described step S of frequency selection.
Returned to 21.

In this way, when a communication error occurs due to communication stop on the side of the lane controller 26, the ETC vehicle-mounted device 10 is
Steps S23 and S2 for initial connection described above
7 or step S related to ETC transaction
24 and S28 are repeatedly executed. This means that unnecessary operations are repeated for the ETC vehicle-mounted device 10. Further, since the vehicle 12 equipped with the ETC vehicle-mounted device 10 is moving even while the useless operation is repeated, for example, while passing through the first communication zone 28, that is, on the lane control device 26 side. It may not be possible to complete the exchange of charge collection information by the time the specified reception electric field for stopping communication (point C in FIG. 4) is reached.

The present invention eliminates unnecessary communication operations that are repeated due to communication errors due to fluctuations in the received electric field, and makes it possible to reliably complete communication of toll collection information and its communication. The purpose is to provide a control method.

[0029]

The ETC vehicle-mounted device according to the present invention is an ETC vehicle-mounted device that communicates information about toll collection with a roadside device installed at a gate of a tollgate, and an FCMC signal transmitted from the roadside device. Of the received electric field through the communication control unit, and the read electric field is compared with a threshold value for starting communication and a threshold value for stopping communication, the CPU section including the roadside device and the ETC vehicle-mounted device. After the frequency selection is completed, it is determined whether the communication state of the ETC vehicle-mounted device is in communication or stopped, and (a) during communication, and when the received electric field exceeds the threshold value for starting communication, And, during communication and when the received electric field is not below the threshold for communication stop even if the received electric field is below the threshold for communication start, the communication state of the ETC vehicle-mounted device is held during communication, On the other hand, when communication is in progress and the received electric field is below the threshold value for starting communication, and when the received electric field is below the threshold value for stopping communication, the communication state of the ETC vehicle-mounted device is transited to the stopped state, and (b ) When it is stopped and the received electric field does not exceed the threshold value for starting communication, the communication state of the ETC vehicle-mounted device is held in the stopped state, while it is stopped and the received electric field is the threshold value for starting communication. When it exceeds, the communication state of the ETC vehicle-mounted device is controlled so as to transit to the communication state.

Further, the communication control method according to the present invention is a communication control method for an ETC vehicle-mounted device, which communicates information on toll collection with a roadside device installed at a gate of a tollgate, wherein an FCMC signal transmitted from the roadside device. The step of reading the received electric field of the above into the CPU section via the communication control section, and the step of comparing the read received electric field with the threshold value of the communication start and the threshold value of the communication stop in the CPU section. In the step, after the frequency selection between the roadside device and the ETC vehicle-mounted device is completed, it is determined whether the communication state of the ETC vehicle-mounted device is in communication or stopped, and (a) the communication is being performed and the reception electric field is Is above the threshold for communication start, and, even during communication and the received electric field is below the threshold for start of communication, the received electric field is below the threshold for stop of communication. If not, the communication state of the ETC vehicle-mounted device is maintained during communication, while communication is in progress and the received electric field is below the threshold value for starting communication, and when the received electric field is below the threshold value for stopping communication. Transitioning the communication state of the ETC vehicle-mounted device to stop, (b) holding the communication state of the ETC vehicle-mounted device in the state of being stopped and the received electric field does not exceed the threshold value of the communication start, On the other hand, it is characterized in that the communication state of the ETC vehicle-mounted device is transited to the state of communication when the ETC vehicle-mounted device is in the stopped state and the received electric field exceeds the threshold value for starting the communication.

According to the present invention, the F transmitted from the roadside unit
The received electric field of the CMC signal is detected, and when the received electric field exceeds the threshold value for communication start, the communication state of the ETC vehicle-mounted device is controlled to transition to the communicating state. On the other hand, the FCM
When the reception electric field of the C signal does not exceed the threshold for communication start, and when the reception electric field of the FCMC signal is below the threshold for communication start and then falls below the threshold for communication stop, It is controlled so that the communication state transitions to the stopped state. Thus, when the communication state of the ETC vehicle-mounted device is stopped, it is possible to omit useless operations such as an operation for initial connection or an operation as an ETC transaction. As a result, even if the operation for exchanging the information on the collection of charges in the ETC on-board unit does not cause a communication error even if it is stopped from the roadside unit due to the condition of the received electric field, the operation of the ETC on-board unit is in the standby state. It is possible to securely complete the communication of the information about the charge collection by holding the information.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of an ETC vehicle-mounted device according to the present invention will be described below in detail with reference to the accompanying drawings. Note that, here, an example in which the ETC system 1 shown in FIG. 3 is applied will be described.

FIG. 1 shows an ETC according to an embodiment of the present invention.
3 is a block diagram of the vehicle-mounted device 10. FIG.

This ETC vehicle-mounted device 10 is an IC card 50
Is removably housed and the information stored in the IC card 50 is read out, and the information regarding the fee collection described later is written between the IC card interface 52 and the CPU section 54. And a security processing unit 58 that encodes and / or encrypts the information to be written, a memory unit 56 for storing the information, and a decryption and / or the information stored in the memory unit 56. A communication control unit 64 including a wireless unit 62 that encodes and performs modulation and demodulation for transmitting and receiving via the wireless antenna 60.
And information about the charge collection (vehicle information, entrance toll gate information, payment information, billing information, charge collection history, etc.), information stored in the IC card 50, operation status of the ETC vehicle-mounted device 10, etc. to the user. It is composed of a display unit 66 for notifying, a timekeeping unit 57 for counting the specific information stored in the memory unit 56 to be valid for a predetermined time, and a CPU unit 54 for integrally controlling the components of each unit. To be done.

In the IC card 50, payment information such as the credit card number of the user, the account number of the financial institution, etc., the expiration date of the contract, and the ID number for specifying the IC card 50 are stored in advance. Has been done. Further, when the vehicle 12 passes through the gate of the entrance toll gate, information such as the entrance toll gate number, the date and time of passage, vehicle information of the vehicle 12 and a charge collection history are stored in the IC card 50.

The display section 66 is stored in the IC card 50 and the above-mentioned information regarding the charge collection based on the control result of the CPU section 54 by means of voice output means, character and image output means or alarm output means such as a buzzer. The user is notified of the information and the operating status of the ETC vehicle-mounted device 10.

ETC vehicle-mounted device 1 according to the embodiment of the present invention
0 is basically configured as described above,
Next, the operation and action of the ETC vehicle-mounted device 10 will be described in relation to the communication control method thereof with reference to the operation flowchart shown in FIG.

In FIG. 3, when the vehicle 12 equipped with the ETC vehicle-mounted device 10 enters the relevant lane at the gate at the entrance toll gate, the lane control device 26, which is the roadside unit, detects the first roadside based on the detection signal of the vehicle type discrimination unit 22. An FCMC (frame control message channel) signal is transmitted as a prescribed polling signal via the antenna 24.

On the ETC vehicle-mounted device 10 side, the FCMC signal is received, and step S1 for frequency selection is executed based on the command from the CPU section 54. Here, in order to tune to the communication frequency used for the first roadside antenna 24, a scanning operation of the communication frequency is performed. By this scanning operation, the communication frequency of the first roadside antenna 24 is detected, and the operations of steps S1 and S2 are repeatedly executed until the selection is completed in step S2. As the communication frequency, a prescribed frequency is stored in the ETC vehicle-mounted device 10 in advance. In this way, the communication state of the ETC vehicle-mounted device 10 is set to communication.

When the communication frequency with the first roadside antenna 24 is selected, the CPU section 54 of the ETC vehicle-mounted device 10 is subsequently selected.
Inside, an operation for initial connection via the first roadside antenna 24 is executed.

First, it is determined whether the communication state of the ETC vehicle-mounted device 10 is stopped (step S3). When the communication state of the ETC vehicle-mounted device 10 is not stopped, that is, when communication is in progress {NO in step S3}, the FC detected by the communication control unit 64 via the wireless antenna 60.
The received electric field of the MC signal is read by the CPU section 54 (step S4).

Next, in the CPU section 54, it is judged whether or not the received electric field exceeds -60.5 dBm (see FIG. 4) which is a threshold value for starting communication defined on the ETC vehicle-mounted device 10 side (see FIG. 4). Step S5). When the received electric field exceeds the prescribed threshold value for starting communication (NO in step S5), the operation for communication proceeds to step S6. The threshold value for starting communication is set in advance in the CPU 54 and stored in the memory 56.

Subsequently, it is determined whether or not a request to transmit an ACTC (Activation Channel: In-vehicle device communication start) signal is received from the lane control device 26 via the first roadside antenna 24 (step S6). This ACTC
When the signal transmission request is not received (step S6)
No.), the operation for communicating has not started on the side of the lane control device 26, etc.
There is no initial connection with the lane control device 26 via the roadside antenna 24. Therefore, steps S8 and S for exchanging the information of the fee collection as the subsequent ETC transaction.
10 and S12 are all NO, and the operation for communicating is returned to step S3.

On the other hand, NO in step S3 and S4 described above.
If the request for transmitting the ACTC signal is received in step S6 after NO in step S5 and step S5, {step S
6 YES}, ETC on-board unit 10 to ACTC
A signal is transmitted (step S7). When the ACTC signal is accepted by the lane control device 26, a connection confirmation signal is returned and the ETC vehicle-mounted device 10 is initially connected to the lane control device 26 via the first roadside antenna 24.

Then, in order to exchange the information of the charge collection as an ETC transaction, first, the ETC vehicle-mounted device 10
The CPU section 54 determines whether or not the MDC (message data channel) signal for transmitting communication information including the charge collection information is received (step S8).
When this MDC signal is not received (step S8)
No), the operation for communicating proceeds to step S10.

On the other hand, NO or S in step S3 described above.
When the MDC signal is received in step S8 (NO in step S8) after passing through S4, NO in S5, YES in S6, and S7, the CPU unit 54 causes the MDC signal to be received.
Signal reception processing is performed (step S9).

Next, it is determined whether or not there is an MDC signal to be transmitted from the ETC vehicle-mounted device 10 to the lane control device 26 (step S10). When there is no MDC signal to be transmitted (NO in step S10), the operation for communicating proceeds to step S12. On the other hand, when there is an MDC signal to be transmitted (YES in step S10), the ETC vehicle-mounted device 1
The CPU unit 54 of 0 transmits the MDC signal including necessary communication information (step S11).

Then, ACKC (ACK channel: for notifying whether or not the MDC signal is normally communicated).
It is determined whether or not the confirmation response channel) signal is received (step S12). When the ACKC signal is not received (NO in step S12), the lane control device 26 side does not transmit the ACKC signal because it is considered that the communication of the MDC signal is not completed. Therefore, the communication operation on the ETC vehicle-mounted device 10 side is returned to step S3.

On the other hand, in step S12, MD
When it is considered that the communication of the C signal is completed, ACKC
The signal is transmitted. In the ETC vehicle-mounted device 10, the ACKC is transmitted from the lane control device 26 via the first roadside antenna 24.
The signal is received (YES in step S12), the ACK
The reception processing of the C signal is performed (step S13), and the operation for communicating is completed.

By the way, in the step S5, when the received electric field does not exceed the specified threshold for communication start (YES in step S5), the received electric field is stopped by the lane control device 26 side. It is determined whether or not the value is below −65.5 dBm, which is the same as the threshold value of (step S14). When the received electric field exceeds the threshold value for stopping communication (NO in step S14), the operation for communicating proceeds to step S6. On the other hand, when the communication is below the threshold for stopping communication (refer to points A to B in FIG. 4), the communication state of the ETC vehicle-mounted device 10 is changed from being communicating to being stopped by a command from the CPU unit 54 of the ETC vehicle-mounted device 10. (Step S15). Therefore, the subsequent step S6 for initial connection and steps S8, S10 and S12 as the ETC transaction are all NO, and the operation for communication is returned to step S3. The threshold value for this communication stop is set in advance in the CPU section 54.
And is stored in the memory unit 56.

Subsequently, in step S3, since the communication state of the ETC vehicle-mounted device 10 is changed from communicating to stopped in step S15, the step S15 is performed.
The determination in 3 is YES, and the operation for communicating proceeds to step S16. Here, ETC vehicle-mounted device 1
At 0, as in step S4 described above, the reception electric field of the FCMC signal detected by the communication control unit 64 is read by the CPU unit 54 via the wireless antenna 60 (step S4).
16).

Next, in the CPU section 54, it is judged whether or not the received electric field exceeds a prescribed threshold value for starting communication (step S17). When this received electric field exceeds the specified threshold for starting communication (YES in step S17), C
After transitioning the communication state of the ETC vehicle-mounted device 10 from the stopped state to the communicating state according to a command from the PU unit 54 (step S18),
The operation for communicating is returned to step S3. In step S3, the communication state of the ETC vehicle-mounted device 10 is changed from being stopped to being in communication, so the determination in step S3 is NO. Subsequently, the operation for communicating is executed based on steps S4 to S15 described above.

On the other hand, in step S17, when the received electric field does not exceed the specified threshold for starting communication (NO in step S17), the operation for communication is returned to step S3. Since the communication state of the ETC vehicle-mounted device 10 is stopped, the determination in step S3 becomes YES again. That is, until the reception electric field of the FCMC signal detected by the communication control unit 64 exceeds the threshold value for starting communication, the operation on the ETC vehicle-mounted device 10 side only repeats steps S3, S16, and S17. Therefore, as long as the received electric field of the FCMC signal does not exceed the threshold value for starting communication, the ETC vehicle-mounted device 10 holds the communication state in the stopped state, and steps S3 and S16.
And S17 are repeatedly executed. As a result, the operation for initial connection, the operation as the ETC transaction, etc. are not executed, and the useless operation in the ETC vehicle-mounted device 10 can be omitted.

In the above-mentioned ETC vehicle-mounted device 10, the case of communicating with the lane control device 26 via the first roadside antenna 24 has been described, but the case of communicating with the lane control device 26 via the second roadside antenna 36. However, it goes without saying that it is executed based on steps S1 to S18 described above.

As described above, according to the ETC vehicle-mounted device 10 and the communication control method therefor according to the embodiment of the present invention, the FCMC signal transmitted from the lane control device 26 via the first roadside antenna 24 is received. When the electric field is detected and the received electric field exceeds the threshold for starting the specified communication, the communication state of the ETC vehicle-mounted device 10 is controlled to transit from the stopped state to the communicated state. On the other hand, when the received electric field does not exceed the specified communication start threshold value and after it is determined that the received electric field has exceeded the specified communication start threshold value, the communication stop specified by the lane control device 26 side is stopped. When it falls below the threshold value of, the communication state of the ETC vehicle-mounted device 10 is controlled so as to transit from the communicating state to the stopped state. As a result, when the communication state of the ETC vehicle-mounted device 10 is stopped,
ACTC signal transmission operation or ET for initial connection
It is possible to omit useless operations such as an operation of receiving an MDC signal as a C transaction. As a result, ETC
Even if the operation for communicating the information on the collection of charges in the vehicle-mounted device 10 is stopped from the lane control device 26 side due to the condition of the received electric field, a communication error does not occur and the operation of the ETC vehicle-mounted device 10 is in a standby state. It is possible to securely complete the communication of the information about the charge collection by holding the information.

[0056]

According to the present invention, the following effects can be obtained.

That is, even if the operation for exchanging the information of the fee collection in the ETC vehicle-mounted device is stopped from the roadside unit due to the condition of the received electric field, a communication error is not generated and the information of the fee collection is surely received. The communication can be completed.

[Brief description of drawings]

FIG. 1 is a block diagram of an ETC vehicle-mounted device according to an embodiment of the present invention.

FIG. 2 is an operation flowchart of the ETC vehicle-mounted device according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an ETC system according to the present embodiment.

FIG. 4 is an explanatory diagram showing a state of a reception electric field of the ETC vehicle-mounted device.

FIG. 5 is an operation flowchart of the ETC vehicle-mounted device according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... ETC system 10 ... ETC onboard equipment 24 ... 1st roadside antenna 26 ... Lane control device (roadside machine) 36 ... 2nd roadside antenna 50 ... IC card 52 ... IC card interface 54 ... CPU part 56 ... Memory part 58 ... Security Processing unit 60 ... Wireless antenna 64 ... Communication control unit 66 ... Display unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Juichiro Kimura             5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan             Wireless Co., Ltd. (72) Inventor Naoto Yoshida             5-1-1 Shimorenjaku, Mitaka City, Tokyo Japan             Wireless Co., Ltd. F-term (reference) 3E027 EA01 EB02 EC07

Claims (2)

[Claims] 1. An ETC vehicle-mounted device for communicating toll collection information with a roadside device installed at a tollgate, wherein the received electric field of an FCMC signal transmitted from the roadside device is:
A CPU that reads through the communication control unit and compares the read received electric field with a communication start threshold value and a communication stop threshold value.
After the frequency selection between the roadside device and the ETC vehicle-mounted device is completed, the CPU unit determines whether the communication state of the ETC vehicle-mounted device is communicating or stopped, and (a) communicating. And the reception electric field exceeds the threshold value for communication start, and the reception electric field is lower than the threshold value for stopping communication even during communication and the reception electric field is lower than the threshold value for communication start. If not, the communication state of the ETC vehicle-mounted device is maintained during communication, while communication is in progress and the received electric field is below the threshold value for starting communication, and the received electric field is below the threshold value for stopping communication. Sometimes, the communication state of the ETC vehicle-mounted device is transited to the stopped state, and (b) when the state of the communication is stopped and the received electric field does not exceed the threshold value for starting the communication, the communication state of the ETC vehicle-mounted device is held in the stopped state. Whereas, the ETC is when and the received electric field is stopped exceeds a threshold value of the communication start
An ETC vehicle-mounted device, characterized in that the communication state of the vehicle-mounted device is controlled so as to transition to a state during communication. 2. A communication control method for an ETC vehicle-mounted device, which communicates information of toll collection with a roadside device installed at a tollgate, wherein the received electric field of an FCMC signal transmitted from the roadside device is:
A step of reading the received electric field with a threshold value for communication start and a threshold value for communication stop in the CPU section via the communication control section; and in the comparing step, the roadside After the frequency selection between the ETC vehicle-mounted device and the ETC vehicle-mounted device is completed, it is determined whether the communication state of the ETC vehicle-mounted device is in communication or stopped. When the threshold value is exceeded, and when the reception electric field is under communication and the reception electric field is lower than the communication start threshold value, but the reception electric field is not lower than the communication stop threshold value, the communication state of the ETC vehicle-mounted device is set. The ET is held during communication, while the communication is in progress and the received electric field is below the threshold value for starting communication, and the received electric field is below the threshold value for stopping communication. (B) hold the communication state of the ETC vehicle-mounted device while the communication state of the C vehicle-mounted device is stopped, and (b) hold the communication state of the ETC vehicle-mounted device when the received electric field does not exceed the threshold value of the communication start; , The ETC is stopped and the received electric field exceeds the threshold value for starting the communication.
A communication control method for an ETC vehicle-mounted device, characterized in that the communication state of the vehicle-mounted device is transited during communication.