CN112149785A

CN112149785A - Pass card reading and writing equipment, anti-interference method and equipment

Info

Publication number: CN112149785A
Application number: CN202011257575.3A
Authority: CN
Inventors: 李明; 王光辉; 李旭
Original assignee: Guangzhou Huihao Computer Technology Development Co ltd
Current assignee: Guangzhou Huihao Computer Technology Development Co ltd
Priority date: 2020-08-04
Filing date: 2020-11-11
Publication date: 2020-12-29
Anticipated expiration: 2040-11-11
Also published as: CN112149785B

Abstract

A pass card read-write device comprises a read-write circuit, an NFC induction circuit, a 5.8G module and a 5.8G antenna. The read-write circuit is used for reading and writing information in the pass card. The NFC induction circuit is used for generating a control signal when the read-write circuit reads and writes information in the pass card. The 5.8G module is used for generating an interference signal according to the control signal and sending the interference signal to the outside through the 5.8G antenna. In the access card reading and writing device, an interference signal is generated through a 5.8G module. The 5.8G part in the composite access card cannot normally receive the antenna signal of the portal RSU due to the shielding effect of the interference signal. Therefore, the composite transit card can not generate 5.8G interruption in the payment process, and the payment process can be smoothly finished.

Description

Pass card reading and writing equipment, anti-interference method and equipment

Technical Field

The invention relates to the field of intelligent transportation, in particular to a pass card reading and writing device, and an anti-interference method and device for reading and writing a pass card.

Background

With the continuous development of the expressway in China, a huge expressway traffic network is formed at present, the number of crossed lines of the expressway is increased, but the loop phenomenon causes a difficult problem in expressway toll collection operation, namely a 'path ambiguity problem'. Therefore, the ambiguous path recognition system is applied, the system reduces the operation cost of the highway, realizes the networking charging of each highway and reasonably splits the fee. The MTC (Manual Toll Collection system) vehicle takes a composite pass card as a path information carrier to realize path identification or charging.

At present, a composite access card antenna comprises two parts, namely 5.8G and 13.56M, an MTC vehicle enters an entrance by using a 13.56M read-write device, an entrance information is written, a 5.8G module is opened, the vehicle runs near a portal RSU antenna, and marking or charging of a corresponding path is completed through a DSRC signal of 5.8G. And then, carrying out export transaction operation at an export position through 13.5M read-write equipment, and closing the 5.8G module after the transaction is finished. However, the existing composite passing card sometimes has the phenomenon of unsmooth fee deduction transaction when the fee is deducted, thereby affecting the passing efficiency of the vehicle at the exit.

Disclosure of Invention

Based on the above problems, the embodiment of the invention provides a pass card reading and writing device, an anti-interference method and an anti-interference device, aiming at solving the problem that the fee deduction transaction of a composite pass card is not smooth when the fee is deducted.

Research shows that the root cause of the problem that the composite pass card causes unsmooth fee deduction transaction is as follows: at present, an omnidirectional receiving antenna is mostly adopted on a 5.8G module of the composite access card, so that the composite access card has high receiving sensitivity, and the former has higher priority response level when the 5.8G module and the 13.56M module are simultaneously opened. Because part of the exit positions are closer to the antenna of the portal RSU (Road Side Unit), the composite pass card in the area range of the reader-writer of the exit toll station can still receive 5.8G weak signals of the antenna of the portal RSU, so that the phenomenon of unsmooth transaction is shown because the composite pass card responds to the 5.8G signals preferentially when 13.56M read-write equipment carries out exit toll operation, and the passing efficiency of exit vehicles is further influenced.

Based on this, the embodiment of the invention provides a pass card read-write device, which comprises a read-write circuit, an NFC induction circuit, a 5.8G module and a 5.8G antenna. The read-write circuit is used for reading and writing information in the pass card. The NFC induction circuit is used for generating a control signal when the read-write circuit reads and writes information in the pass card. The 5.8G module is used for generating an interference signal according to the control signal and sending the interference signal to the outside through the 5.8G antenna.

Optionally, the access card read-write device further includes an amplifying circuit, the amplifying circuit is disposed between the NFC sensing circuit and the 5.8G module, and the amplifying circuit is configured to amplify the control signal output by the NFC sensing circuit and output the amplified control signal to the 5.8G module.

Optionally, the amplifying circuit includes a first transistor Q1, a base of the first transistor Q1 is connected to the NFC sensing circuit through a first resistor R31, and is grounded through a second resistor R30, an emitter of the first transistor Q1 is grounded, a collector of the first transistor Q1 is connected to the 5.8G module and is connected to a power supply voltage through a third resistor R32, and the collector of the first transistor Q1 is grounded through a first capacitor C3.

Optionally, the amplifying circuit further includes a first diode D1, an anode of the first diode D1 is connected to the NFC sensing circuit, and a cathode of the first diode D1 is connected to the first resistor R31.

Optionally, the pass card read-write equipment further includes a power supply circuit, the power supply circuit includes power supply chip U1, power supply chip U1 includes power input pin, voltage output pin and ground pin, power input pin connects mains voltage, ground pin ground connection, voltage output pin passes through second electric capacity C8 ground connection, voltage output pin is connected to through fourth resistance R4 the 5.8G module is used for exporting analog voltage, voltage output pin is connected to through fifth resistance R36 the 5.8G module is used for exporting digital voltage.

Optionally, the interference signal is a continuous random signal of the same frequency.

Optionally, the interfering signal is a continuous PN9 (Pseudo-Noise) signal.

Optionally, the signal strength emitted by the 5.8G module is less than or equal to 0 dbm.

Optionally, the transmission power P of the interference signal should satisfy P ≧ 67+20Log (L1) -G101-G102, where G101 is the gain of the 5.8G antenna, and the unit is dbi; g102 is the antenna gain received by the pass card, and the unit is dbi; l1 is the distance between the pass card and the 5.8G antenna, and is given by Km.

Optionally, the access card reading and writing device further includes a communication interface, the communication interface is connected to the 5.8G module, and the communication interface is configured to receive a control signal sent by an upper computer to control the 5.8G module to generate an interference signal.

The embodiment of the invention also provides an anti-interference method for the access card reading and writing equipment, which comprises the following steps:

providing an NFC induction circuit, wherein the NFC induction circuit is used for generating a control signal when the read-write circuit reads and writes information in the pass card;

and providing a 5.8G module and a 5.8G antenna, wherein the 5.8G module is used for generating an interference signal according to the control signal and sending the interference signal to the outside through the 5.8G antenna.

The embodiment of the invention also provides an anti-interference device, which is used for reading and writing the pass card and comprises the following components: the NFC induction circuit is used for generating a control signal when the read-write equipment reads and writes information in the access card, the 5.8G module is used for generating an interference signal according to the control signal and sending the interference signal to the outside through the 5.8G antenna.

In the pass card reading and writing device, the anti-interference method and the anti-interference device provided by the embodiment of the invention, when the reading and writing circuit reads and writes information in the pass card, the control signal is generated through the NFC induction circuit, then the interference signal is generated through the 5.8G module according to the control signal, and the interference signal is sent to the outside through the 5.8G antenna. At this time, the 5.8G part in the composite access card cannot normally receive the antenna signal of the portal RSU due to the shielding effect of the interference signal. Therefore, the composite pass card cannot generate 5.8G interruption in the outlet writing process, and the operation of the whole outlet writing process can be smoothly completed.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a system block diagram of a pass card read-write device according to an embodiment of the present invention.

Fig. 2 is a schematic circuit diagram of an amplifying circuit according to an embodiment of the present invention.

Fig. 3 is a circuit schematic of the 5.8G module of fig. 1.

Fig. 4 is a circuit schematic of the power supply circuit of fig. 1.

Fig. 5 is a schematic diagram of an anti-interference method for a pass card read/write device according to another embodiment of the present invention.

Fig. 6 is a system block diagram of an anti-jamming device according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein, and that the terms "comprises" and "comprising," and any variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 1, an embodiment of the invention provides a pass card read-write device 100, which includes a read-write circuit 110, an NFC sensing circuit 120, a 5.8G module 130, and a 5.8G antenna 140. The read-write circuit 110 is used for reading and writing information in the pass card. The NFC sensing circuit 120 is configured to generate a control signal when the read/write circuit 110 reads and writes information in a pass card. The 5.8G module 130 is configured to generate an interference signal according to the control signal, and send the interference signal to the outside through the 5.8G antenna 140. Specifically, the read/write circuit 110 reads and writes information in the access card by using a Radio Frequency Identification (RFID) technology, which is a non-contact automatic Identification technology implemented by using a Radio Frequency communication technology. The read-write circuit 110 is provided with a reader-writer antenna, the pass card is provided with a tag antenna, and the read-write circuit 110 and the pass card perform energy transfer and communication in an inductive coupling mode. During reading and writing, the antenna coil of the reading and writing circuit 110 generates a high-frequency strong electromagnetic field, and the magnetic field penetrates through the cross section of the coil and the space around the coil, so that the tag antenna close to the antenna coil of the reader-writer generates an induced voltage in an alternating magnetic field. The induced voltage passes through the rectifying and filtering capacitor and then activates the internal circuit of the pass card, and the pass card sends the information stored in the ROM to the read-write circuit 110. The read/write circuit 110 then reads and writes the information inside the access card through its internal antenna. In the process that the read/write circuit 110 sends information to the access card through the antenna, the NFC sensing circuit 120 may sense a signal sent by the antenna of the read/write circuit 110, so as to generate a control signal to the 5.8G module 130, so that the 5.8G module 130 generates an interference signal. At this time, the 5.8G part in the composite access card cannot normally receive the antenna signal of the portal RSU due to the shielding effect of the interference signal. Therefore, the composite passing card cannot generate 5.8G interruption in the outlet writing process, and the operation of the whole outlet writing process can be smoothly completed.

Referring to fig. 2, the access card reading/writing device 100 further includes an amplifying circuit 150. The amplifying circuit 150 is disposed between the NFC sensing circuit 120 and the 5.8G module 130. The amplifying circuit 150 is configured to amplify the control signal output by the NFC sensing circuit 120 and output the amplified control signal to the 5.8G module 130. Since the sensing signal generated by the NFC sensing circuit 120 is weak, the signal strength of the sensing signal needs to be improved by the amplifying circuit 150. In this embodiment, the amplifying circuit 150 includes a first transistor Q1. The base of the first transistor Q1 is connected to the NFC sensing circuit 120 through a first resistor R31 and to ground through a second resistor R30. The emitter of the first transistor Q1 is grounded. The collector of the first transistor Q1 is connected to the 5.8G module 130 and to the supply voltage VCC through a third resistor R32. The power supply voltage VCC is a 3.3V DC voltage. The collector of the first transistor Q1 is grounded through a first capacitor C3. The amplifying circuit 150 further includes a first diode D1. The anode of the first diode D1 is connected to the NFC sensing circuit 120, and the cathode of the first diode D1 is connected to the first resistor R31. In use, the NFC sensing circuit 120 acts as a 13.56MHz read/write identification sensor, and includes a 13.56MHz sensing coil ant 2. The induction coil ant2 is disposed within the induction area of the read/write circuit 110. After the voltage induced by the inductor ant2 passes through the first diode D1, the voltage is divided by the voltage dividing circuit formed by the first resistor R31 and the second resistor R30 and then provided to the base of the first triode Q1, and after the voltage is reversely amplified by the collector of the first triode Q1, the voltage is first-order low-pass filtered by the third resistor R32 and the first capacitor C3 and then input to the 5.8G module 130.

Referring to fig. 3, the 5.8G module 130 includes a data receiving pin PA08, antenna signal output pins SL _ ANTP and SL _ ANTN, a digital power input pin HD _ DVDD, and an analog power input pin HD _ AVDD. The data receiving pin PA08 is used for receiving the induced voltage signal transmitted by the NFC sensing circuit 120. In this embodiment, the data receiving pin PA08 is connected to the collector of the first transistor Q1. The antenna signal output pins SL _ ANTP and SL _ ANTN are connected to the 5.8G antenna 140, and are used for controlling the 5.8G antenna 140 to transmit an interference signal according to the induced voltage signal transmitted by the NFC inductive circuit 120. In this embodiment, the 5.8G antenna 140 is a PCB printed omni-directional or directional antenna ant 1. According to the requirement, the interference signal is a continuous random signal with the same frequency. Specifically, the interference signal is a continuous PN9 (Pseudo-Noise) signal. Specifically, the antenna signal output pin positive electrode SL _ ANTP is grounded through a capacitor C23, and the antenna signal output pin negative electrode SL _ ANTN is connected to the 5.8G antenna 140 through a capacitor C22. One end of the capacitor C23 connected with the negative pole SL _ ANTN of the antenna signal output pin is grounded through an inductor L3; one end of the capacitor C23 connected to the 5.8G antenna 140 is grounded through an inductor L4. The capacitor C22, the capacitor C23, the inductor L3 and the inductor L4 are used for realizing double-end to single-end balun conversion and matching. The digital power input pin HD _ DVDD is configured to receive an external input digital voltage, and the external input digital voltage is grounded through a third capacitor C1. The analog power input pin HD _ AVDD is configured to receive an externally input analog voltage, and the externally input analog voltage is grounded through a capacitor C12. The 5.8G module further comprises a communication interface PA09/UART0_ TXD and PA10/UART0_ RXD, wherein the communication interface PA09/UART0_ TXD and PA10/UART0_ RXD are used for receiving control signals sent by an upper computer to control the 5.8G module to generate interference signals.

Referring to fig. 4, the access card reading/writing device 100 further includes a power supply circuit 160. The power supply circuit 160 includes a power supply chip U1. The power supply chip U1 includes a power input pin Vin, a voltage output pin Vout and a ground pin GND. The power input pin Vin is connected with a power voltage VCC. The grounding pin GND is grounded. The voltage output pin Vout is grounded through the fourth capacitor C8 and the fifth capacitor C9, thereby serving to output the power supply voltage VCC. The voltage output pin Vout is connected to the 5.8G module 130 through a fourth resistor R4 for outputting an analog voltage. The voltage output pin Vout is connected to the 5.8G module 130 through a fifth resistor R36 for outputting a digital voltage. The purpose of separating the digital voltage part from the analog voltage part is to reduce the interference that the digital voltage part brings to the analog voltage part.

The operation process of the access card reading and writing device 100 is as follows:

1. the pass card is placed in the sensing area of the read-write circuit 110, and since the NFC sensing circuit 120 is also in the sensing area of the read-write circuit 110, the NFC sensing circuit 120 may receive a signal sent by the pass card when the read-write circuit 110 reads and writes the pass card information.

2. The 5.8G module 130 is initialized after power-on reset and enters an idle state. The timing loop reads the instructions received by the data receiving pin PA08, or the communication interfaces PA09/UART0_ TXD and PA10/UART0_ RXD.

3. The read-write circuit 110 sends a 13.56MHz carrier signal according to ISO14443a protocol in the process of reading and writing the information of the access card. According to the faraday's electromagnetic induction principle, the inductive coil of the NFC sensing circuit 120 will generate an induced voltage U1, which passes through the first diode D1, the first resistor R31 and the second resistor R30 to generate an input voltage U2 at the base of the first transistor Q1. Wherein, U2 ═ (U1-0.6) × R30/(R31+ R30). The input voltage U2>0.6V and the first transistor Q1 are turned on by the values of the first resistor R31 and the second resistor R30, so that the input voltage U2 reversely amplifies and outputs a low level to the 5.8G module 130.

4. After the data receiving pin PA08 of the 5.8G module 130 receives the low level output by the amplifying circuit 150, it initializes the internal register to transmit a 5.8G radio frequency to enter an interference mode, thereby sending an interference signal. The specific frequency of the interference signal should correspond to the frequency point of the antenna of the mast RSU, and is 5.83GHz or 5.84 GHz. The interference signal is a continuous random signal with the same frequency. Specifically, the interference signal is a continuous PN9 (Pseudo-Noise) signal. The transmission power P of the interfering signal should be as low as possible if the reception threshold of the pass card is met. The received signal strength of the pass card is typically > 40 (dbm). In practical application, the gain of the 5.8G antenna 140 is G101(dbi), the gain of the antenna received by the pass card is G102(dbi), and when the distance between the pass card and the 5.8G antenna 140 is L1(Km), the transmission power P of the interference signal should satisfy P ≧ 67+20Log (L1) -G101-G102.

5. After the read-write circuit 110 finishes reading and writing the pass card information, the data receiving pin PA08 recovers the high level, and the 5.8G module 130 closes the 5.8G antenna 140 and returns to the idle state after the level is read for a delay time of t.

Referring to fig. 5, an embodiment of the present invention further provides an anti-interference method for a pass card read-write device, including:

Referring to fig. 6, according to needs, an embodiment of the present invention further provides an anti-jamming device 200, configured to read and write a passcard, including: the NFC sensing circuit 210 is used for generating a control signal when a read-write device reads and writes information in a pass card, the 5.8G module 220 is used for generating an interference signal according to the control signal and sending the interference signal to the outside through the 5.8G antenna 230. The tamper-resistant device 200 may also include amplification circuitry, power supply circuitry 260, and a communication interface 270, as desired, and will not be described in detail herein.

It should be noted that the above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations and simplifications which do not depart from the spirit and principle of the present invention should be regarded as equivalent substitutions and are included in the protection scope of the present invention.

Claims

1. The access card reading and writing device is characterized by comprising a reading and writing circuit, an NFC induction circuit, a 5.8G module and a 5.8G antenna, wherein the reading and writing circuit is used for reading and writing information in an access card, the NFC induction circuit is used for generating a control signal when the reading and writing circuit reads and writes the information in the access card, and the 5.8G module is used for generating an interference signal according to the control signal and sending the interference signal to the outside through the 5.8G antenna.

2. The access card reading and writing device of claim 1, further comprising an amplifying circuit, wherein the amplifying circuit is disposed between the NFC sensing circuit and the 5.8G module, and the amplifying circuit is configured to amplify the control signal output by the NFC sensing circuit and output the control signal to the 5.8G module.

3. The pass card reader/writer apparatus of claim 1 wherein the amplifying circuit comprises a first transistor Q1, the base of the first transistor Q1 is connected to the NFC sensing circuit through a first resistor R31 and to ground through a second resistor R30, the emitter of the first transistor Q1 is connected to ground, the collector of the first transistor Q1 is connected to the 5.8G block and to the supply voltage through a third resistor R32, and the collector of the first transistor Q1 is connected to ground through a first capacitor C3.

4. The access card reader/writer apparatus of claim 3 wherein said amplifier circuit further comprises a first diode D1, an anode of said first diode D1 being connected to said NFC sensing circuit, and a cathode of said first diode D1 being connected to said first resistor.

5. The pass card reader/writer of any one of claims 2-4 further comprising a power supply circuit, said power supply circuit comprising a power supply chip U1, said power supply chip U1 comprising a power input pin, a voltage output pin and a ground pin, said power input pin being connected to a power supply voltage, said ground pin being connected to ground, said voltage output pin being connected to ground through a second capacitor C8, said voltage output pin being connected to said 5.8G module through a fourth resistor R4 for outputting an analog voltage, said voltage output pin being connected to said 5.8G module through a fifth resistor R36 for outputting a digital voltage.

6. The access card reading/writing device of claim 1, wherein the interference signal is a continuous random signal of the same frequency.

7. The access card reader/writer device of claim 6 wherein said interference signal is a continuous PN9 signal.

8. The pass-card reader/writer apparatus of claim 1, wherein the transmission power P of the interference signal is such that P ≧ 67+20Log (L1) -G101-G102, where G101 is the gain of the 5.8G antenna in unit dbi; g102 is the antenna gain received by the pass card, and the unit is dbi; l1 is the distance between the pass card and the 5.8G antenna, and is given by Km.

9. An anti-interference method for a pass card read-write device comprises the following steps:

10. An anti-jamming device for access card reading and writing, comprising: the NFC induction circuit is used for generating a control signal when the read-write equipment reads and writes information in the access card, the 5.8G module is used for generating an interference signal according to the control signal and sending the interference signal to the outside through the 5.8G antenna.