JP3089170B2 - Wireless toll collection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to tolls on toll roads.
About the applicable wireless toll collection system to a predetermined or the like.

[0002]

2. Description of the Related Art Conventionally, for example, in a toll collection system at a tollgate on a toll road, a system in which a collection member directly collects cash from a driver has been adopted. Therefore, the driver had to stop the vehicle once at the toll booth and hand over the cash. Therefore, as a future fee collection system,
A non-stop cashless system using a non-contact IC card has been developed.

FIG. 5 shows an example of the configuration of this type of system.
In FIG. 5, a non-contact IC card 8 is affixed to the inside of a vehicle 2a which is a moving body, for example, an inner surface of a windshield, and the non-contact IC card 8 is unique to the vehicle 2a (having the card 8). Information such as an ID number is stored. On the other hand, a ground station 5 having an antenna 3a is provided at a gate of the tollgate, and is connected to a terminal computer 6 of the tollgate via a wireless device 9.

In such a system, a non-contact IC
When the vehicle 2a having the card 8 passes below the antenna 3a, information such as an ID number and a toll is automatically wirelessly communicated between the antenna 3a and the non-contact IC card 8. These pieces of information are recognized by the wireless device 9 constituting the ground station 5, transmitted to the terminal computer 6, and stored in the memory of the computer 6. Further, the information is transmitted to the host computer 7 connected to the ground station 5, and the settlement of the toll is automatically performed from the bank account registered by the vehicle 2a passing through the tollgate.

Here, a wireless communication between the antenna 3a of the ground station 5 and the non-contact IC card 8 uses a time division multiple access (TDMA) communication system. This communication method is
A specific time zone is assigned to a communication party, and communication is performed in the assigned time zone.

Hereinafter, the time division multiple access communication system will be described. First, it is assumed that the vehicle 2a has entered the tollgate gate 1, as shown in FIG. At this time, a radio wave from the ground station 5 is transmitted from the antenna 3a to the non-contact IC card 8 (see FIG. 5) of the vehicle 2a.

If the vehicle 2a enters the toll gate 1, as shown in FIG. 6, another vehicle 2a enters another lane.
When b and 2c also enter, the transmission from the ground station 5 to the non-contact IC cards of these three vehicles 2a to 2c is performed as follows. The allocation time is sequentially switched from the antenna 3a to the non-contact IC card of the vehicle 2a, then from the antenna 3b to the non-contact IC card of the vehicle 2b, and further from the antenna 3c to the non-contact IC card of the vehicle 2c, and the same frequency signal f ₁ is transmitted.

[0008] Thereafter, transmission from the vehicles 2a to 2c to the ground station 5, first from the vehicle 2a (the non-contact IC card) to the antenna 3a, then from the vehicle 2b (the non-contact IC card) to the antenna 3b, and further to Non-contact I of the vehicle 2c (
C card) to the antenna 3c, and sequentially to the same frequency f ₁
Is transmitted.

The above is the communication between the antenna of the ground station and the non-contact IC card of the vehicle by the time division multiple access communication system. The concept of this communication system is shown in FIG. Note that perform division multiple access (TDMA) communication when the above, as shown in FIG. 8, a local oscillator antenna 3a which is installed in each lane, the frequency emitted from 3b which oscillates at (the same frequency f ₁ All identical (f ₁ ) by radio 9 with 10)
Therefore, the response frequencies from the non-contact IC card 8 are all the same, and it is to avoid that data from a plurality of vehicles cannot be identified due to interference. Here, FIG.
The details of the configuration are the same as in the configuration of FIG. 1 described later except for the oscillation frequency of the local oscillator 10, and therefore the description is omitted.

[0010]

As described above, the non-contact I
According to the toll collection system using the C card, a non-stop and cashless toll collection system can be realized. However, time division multiple access (TDM)
A) In the conventional system to which the communication method is applied, the radio frequency is time-divided as described above, and communication is performed in the time zone allocated to the communication person. When the vehicle (mobile) passes, wireless communication is performed sequentially by switching the assigned time zone for each vehicle, and there is a possibility that it takes time to collect the toll. Therefore, the present invention provides a wireless toll collection system capable of high-speed processing even when a large number of moving objects pass in a toll booth in a short time.
The purpose is to provide a stem .

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and in order to achieve the object , a fee having a plurality of lanes.
Via the antenna provided for each lane of the gate
Provided on the moving body passing through the corresponding lane.
A contactless IC card transmitted from the antenna
The same frequency using the frequency of the signal
Wireless communication with a contactless IC card that returns a response signal
In the toll collection system that performs toll collection processing by performing
From the antenna for each lane, it differs for each lane
Time-division / frequency transmission of transmission signals in frequency and time-division
A number-division multiple-access communication means, wherein in the transmission signal,
Type of response to the signal from the contactless IC card
To make the same in each lane
Sends the transmission signal with response timing information
Time division / frequency division multiple access communication means .

[0012]

In the wireless toll collection system having the above configuration ,
Non-contact IC of moving object from antenna for each lane on the ground station side
Transmission to the card is performed at a different frequency for each lane.
This is performed by time division / frequency division multiple access communication in which a transmission signal is transmitted in a time division manner . At this time,
Should respond to the signal from the contactless IC card side.
To make the same timing for each lane.
The response timing information for
Transmission from contact IC card to ground station is frequency division multiple access
It is performed by continuous communication. Therefore, it is not necessary to allocate a different communication time zone to each mobile unit and transmit in order in order to transmit from the mobile unit to the ground station, and transmission from the mobile unit to the ground station that has entered almost simultaneously does not cause interference. Can be performed simultaneously and in parallel, thereby shortening the processing time at the toll booth.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, in which the present invention is applied to a contactless IC card device applied to an automatic toll collection system as shown in FIGS. Note that the ground station in this embodiment (the wireless device)
Is different from the ground station (the wireless device thereof) in the automatic toll collection system of FIGS. 4 and 5, but the system configuration itself does not change. Therefore, FIGS. 4 and 5 are used for convenience.

FIG. 1 shows a ground station (ground machine) in the embodiment.
3 is a block diagram mainly showing the configuration of a wireless device. FIG.
As shown in FIG. 2, three wireless devices 9a, 9b, 9c are connected to the terminal computer 6, for example. Antennas 3a, 3b, 3c provided for each lane of the tollgate are connected to these wireless devices 9a, 9b, 9c, respectively.

From the terminal computer 6, each radio 9a
9c, a non-modulated wave (Continuous Wave) control signal (hereinafter referred to as a CW control signal) and transmission data are output. These signals are ANDed by an AND circuit 11 provided at an input stage of each of the wireless devices 9a to 9c, and input to a modulator 12.

The local oscillator 1 which oscillates each radio 9a, 9b, the 9c, at different frequencies f _1, f _2, f _3, respectively
0a, 10b, and 10c are provided. The CW from the terminal computer 6 is input to each of the local oscillators 10a to 10c.

A high-frequency power amplifier 13 is connected downstream of the modulator 12 of each of the radios 9a to 9c.
The input of the circulator 14 is connected to the subsequent stage. The circulator 14 of each of the wireless devices 9a to 9c is connected to the antennas 3a to 3c. As a result, the modulated wave modulated by the modulator 12 of each of the wireless devices 9a to 9c is transmitted to the amplifier 1
3 to the required level and the circulator 1
4 and radiated from the antennas 3a to 3c into the air.

The circulator 14 of each of the wireless devices 9a to 9c
Is connected to a low noise amplifier 15. As a result, the radio waves (received waves) from the on-vehicle device (non-contact IC card) received by the antennas 3a to 3c are transmitted to the wireless devices 9a to 9
The signal is input to the low-noise amplifier 15 via the circulator 14c, and is amplified by the amplifier 15 to a required level.

A demodulator 16 is connected downstream of the amplifier 15 of each of the radios 9a to 9c. The same CW (frequency f _{1 to} f ₃ ) used for the transmission wave is input from the oscillators 10 a to 10 c to the demodulator 16 of each of the radios 9 a to 9 c. Thereby, the demodulator 16 demodulates the signal from the vehicle-mounted device (non-contact IC card) by homodyne detection from the CW and the received wave.

At the subsequent stage of the demodulator 16, a converter 17 for amplifying and shaping the demodulated signal and converting it into a digital signal is connected, and the demodulated digital signal output from the converter 17 is supplied to the terminal computer 6 Is input to

As described above, in this embodiment, since the respective radios 9a to 9c of the ground station (ground machine) are configured as shown in FIG. 1, the transmission signals radiated from the antennas 3a to 3c are: The emission timing is controlled by the CW control signal output from the terminal computer 6,
This enables time division multiple access (TDMA) communication. In addition, each of the wireless devices 9a to 9c has a different frequency f _1.
Since the local oscillator 10a~10c which oscillates at ~f ₃ are provided, frequency division multiple access (FDMA) communication is also possible.

Generally, a non-contact IC card 8 serving as a vehicle-mounted device
Have a broadband frequency characteristic. Therefore, the non-contact IC card 8 can respond to any of the radio waves of the frequencies f _{1 to} f ₃ radiated from the antennas 3a to 3c. Therefore, when radio waves are simultaneously emitted from the antennas 3a to 3b to the non-contact IC card 8, interference occurs in the non-contact IC card 8, and normal communication cannot be performed.

In order to avoid this, as shown in FIG. 2, the terminal computer 6 uses a time division multiple access (TDMA).
By sequentially switching the wireless devices 9a to 9c by the communication method,
Signal (radio wave frequency f ₁ ~f ₃₎ is prevented from being simultaneously emitted from the antenna 3 a to 3 c.

The signal (radio wave) received by the non-contact IC card 8 from the ground station includes information indicating the timing at which the card 8 should respond to the signal, for example, the antenna number of the antenna that radiated the signal. (Information indicating). CPU at the center of non-contact IC card 8
(Not shown) indicates the antenna number (included in the signal) received from the ground station when the vehicle provided with the contactless IC card 8 passes through any of the lanes corresponding to the antennas 3a to 3c. The response timing is controlled based on the (response timing information), and even if a signal (radio waves of frequencies f _{1 to} f ₃ ) is received from any of the antennas ₃ a to ₃ c at the corresponding timing, the same as shown in FIG. Responds with timing (this is a point different from the conventional non-contact IC card, and the hardware configuration itself does not change). Therefore, for example, when three vehicles pass through the lanes corresponding to the antennas 3a to 3c almost at the same time, the non-contact IC cards of the three vehicles will
As shown in FIG.

Here, the non-contact IC card 8 generally has a configuration in which it does not have an oscillator for generating a unique frequency inside and reflects while modulating a radio wave radiated from an antenna of a ground station. . Therefore, each radio 9
In a to 9c), a radio wave having the same frequency as that emitted by itself is always received.

As described above, the radios 9a to 9c of the ground station perform homodyne detection (at the demodulator 16).
As described below, signals of different frequencies can be deleted. The homodyne detection in each of the wireless devices 9a to 9c is a method of multiplying the output signal s1 of the local oscillators 10a to 10c by the received signal s2 input from the antennas 3a to 3c via the circulator 14 and the low noise amplifier 15. . The output g of the homodyne detection is expressed by the following equation, taking the demodulator 16 of the wireless device 9a as an example.

[0027] g = s1 × s2 = Acos ( f 1 t) × [B 1 cos {f 1 t + θ 1 (t)} + B 2 cos {f 2 t + θ 2 (t)} + B3 cos {f 3 t + θ 3 (t _{)}] = (AB 1/} 2) cos {θ 1 (t)} + (AB 2/2) cos {(f 1 -f 2) t + θ 2 (t)} + (AB 3/2) cos {( _{f 1 -f 3) t + θ} 3 (t)} + (AB 1/2) cos {2f 1 + θ 1 (t)} + (AB 2/2) cos {(f 1 + f 2) t + θ 2 (t)} _{+ (AB 3/2) cos} {(f 1 + f 3) t + θ 3 (t)} However, in the above formula, B1 to B3 each vehicle passing through the lane corresponding to the antenna 3 a to 3 c (for convenience, and Fig. 6 Similarly the level of the reflected wave in the non-contact IC card of the vehicle 2a~2c and expressed), θ ₁ ~θ ₃ is also the vehicle 2a~2
c represents phase modulation data in the non-contact IC card.

From the above equation, the LPF that allows only the θ ₁ (t) component to pass after the homodyne detection in the demodulator 16
When (Low Pass Filter) placing the output g of the demodulator 16 ', g' becomes _{= (AB 1/2) cos} {θ 1 (t)}.

Here, when θ ₁ (t) = 0, g ′ = A
B _1/2, and the when the _{θ 1 (t) = π g} '= - AB
_{It is 1/2} . That is, at the ground station, positive and negative amplitude information is obtained based on the phase information, and information from the non-contact IC card of the vehicle is demodulated. Therefore, even if radio waves of different frequencies are received simultaneously, normal demodulation is performed.

FIG. 3 shows an arrangement of a plurality of frequency signal spectra transmitted by the above-mentioned ground station. In the figure, f _1, for example the antenna 3a of the ground station is a frequency of the radio wave radiated. Similarly, f ₂ and f ₃ are the antennas 3
b, 3c are the frequencies of the radiated radio waves. These f ₁ ~
f ₃ is (see Fig. 2) to be returned at the same time from the non-contact IC card, similarly to the television channel, interference between the antenna (ground station) does not occur by homodyne detection and LPF in the demodulator 16 described above Thus, frequency separation is performed.

[0031]

As described above in detail, according to the present invention, transmission from a ground station to a mobile unit is performed by time division multiple access (TDMA).
The following special effects can be obtained by adopting a configuration in which the transmission is performed by the communication system and the transmission from the mobile unit to the ground station is performed by the frequency division multiple access (FDMA) communication system.

1) The communication time between the ground station and the mobile can be reduced. 2) Since a communication time can be shortened, a large amount of moving objects can be processed. 3) Reliability is increased because interference is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram mainly showing the configuration of a wireless device of a ground station according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a communication system applied in the embodiment.

FIG. 3 is a diagram showing an example of the arrangement of a plurality of frequency spectra transmitted by a ground station in the embodiment.

FIG. 4 is a diagram showing a state near a toll gate for explaining a toll collection system using a contactless IC card;

FIG. 5 is a diagram showing a basic configuration of an automatic toll collection system using a contactless IC card.

FIG. 6 is a diagram for explaining a communication system applied in a conventional automatic toll collection system.

FIG. 7 is a conceptual diagram of the communication system shown in FIG.

FIG. 8 is a block diagram of a conventional wireless device.

[Explanation of symbols]

1: Toll gate, 2a, 2b, 2c
... vehicles, 3a, 3b, 3c ... antennas, 5 ... ground stations, 6 ... terminal computers, 7 ... host computers, 8 ... contactless IC cards,
9a, 9b, 9c: radio, 10a, 10b, 10c
... local oscillator, 11 ... AND circuit, 12 ... modulator,
13 ... High frequency power amplifier, 14 ...
Circulator 15 ... Low noise amplifier,
16 demodulator, 17 converter.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-243385 (JP, A) JP-A-6-181449 (JP, A) JP-A-6-258425 (JP, A) 55250 (JP, A) JP-A-4-280396 (JP, A) JP-A-2-93390 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G07B 15/00

Claims (1)

(57) [Claims] 1. A tollgate having a plurality of lanes.
Via the antenna provided for each lane,
Contactless IC car installed on a moving body passing through a lane
The signal transmitted from the antenna
A response signal of the same frequency is returned using the frequency of the signal.
Charges for wireless communication with contactless IC cards
In a wireless toll collection system that performs a collection process, a different frequency is set for each lane from the antenna for each lane.
Time-division and frequency division for transmitting transmission signals in numbers and time-division
Split access communication means, wherein the transmission signal includes
Timing that should be answered from the contactless IC card to the signal
For ensuring that the markings are the same for each lane
When sending the transmission signal with timing information
It is specially equipped with division / frequency division multiple access communication means.
Wireless toll collection system.