JP6612659B2 - Human body communication device and entrance / exit management device - Google Patents

Description

  Embodiments described herein relate generally to a human body communication device and an entrance / exit management device.

  An entrance / exit management device for managing entrance / exit to a specific place is generally put into practical use. A human body communication device that communicates with an entrance / exit management device via a human body has also been put into practical use. Such an entrance / exit management device determines whether or not the user can pass to a specific place by performing human body communication with the human body communication device worn by the user.

Japanese Patent No. 5727971

  Generally, a human body communication device mounted on a stationary device such as an entrance / exit management device operates by receiving power from an AC power source such as a commercial power source. In this case, the human body communication device has a problem that the noise of the commercial power source flows into the human body communication device through the floating capacitance of the power transformer used to convert the AC power source to the DC power source, and the communication performance is deteriorated. There is.

  It is an object of the present invention to provide a human body communication device and an entrance / exit management device that can suppress the influence of noise.

  According to one embodiment, the human body communication device includes a first electrode unit, a cancel signal generation unit, and a second electrode unit. The first electrode unit detects a signal propagating through the human body. The cancel signal generation unit generates a cancel signal for canceling a signal having a frequency other than the communication frequency among the signals detected by the first electrode unit. The second electrode unit applies the cancel signal to the human body.

FIG. 1 is an explanatory diagram for explaining a configuration example of an entrance / exit management system according to an embodiment. FIG. 2 is an explanatory diagram for describing an example of a control system of the human body communication device according to the embodiment. FIG. 3 is an explanatory diagram for describing a configuration example of a human body communication circuit unit according to an embodiment. FIG. 4 is an explanatory diagram for describing a configuration example of a signal transmission unit according to an embodiment. FIG. 5 is an explanatory diagram for describing a configuration example of a signal receiving unit according to an embodiment. FIG. 6 is an explanatory diagram for describing a configuration example of a control unit according to an embodiment.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram showing a configuration example of the entrance / exit management system 1. The entrance / exit management system 1 is a system for managing entry / exit of a user to / from a specific place. The entrance / exit management system 1 acquires ticket gate information used for ticket gate processing from an information medium possessed by the user, and determines whether or not the user possessing the information medium can pass based on the acquired ticket gate information. The entrance / exit management system 1 includes a human body communication device 2, an entrance / exit management device (for example, a ticket gate device) 3, and the like.

  The human body communication device 2 communicates (human body communication) with other devices using a user's body (hereinafter referred to as a human body) possessing the human body communication device 2 as a communication medium. The human body communication device 2 induces an electric current in the human body by applying an electric field to the human body with an antenna. Thereby, the human body communication apparatus 2 can propagate a communication signal using the human body as a communication medium. In addition, the human body communication device 2 detects an electric field generated by a communication signal propagated from another device to the human body using an antenna. Thereby, the human body communication apparatus 2 can acquire the communication signal which propagates a human body.

  The entrance / exit management device 3 communicates with the human body communication device 2 possessed by the user to determine whether or not the user can pass. The entrance / exit management device 3 includes a pair of housings 11, a door 12, a human body communication device 13, and a control device 14. A pair of housing | casing 11 comprises the channel | path 15 by arrange | positioning in parallel. The door 12 is provided on the side of the passage 15 of the housing 11, and closes the passage 15 by rotating based on the control of the control device 14.

  Further, for example, the human body communication device 13 performs human body communication with the human body communication device 2 possessed by the user, and acquires ticket gate information. For example, the human body communication device 13 generates an electric field in a predetermined range at the first frequency and induces an electric current in the human body of the user in this range. Thereby, the human body communication apparatus 13 transmits a communication signal to the human body communication apparatus 2 carried by the user via the human body. Further, for example, the human body communication device 13 detects an electric field induced by a communication signal propagating to the user's human body entering a predetermined range. Thereby, the human body communication apparatus 13 acquires the communication signal transmitted from the human body communication apparatus 2 via the human body. The first frequency is a frequency band used for human body communication, and is within a range of, for example, less than 1 MHz.

  The control device 14 acquires ticket gate information based on the communication signal detected by the human body communication device 13. The control device 14 performs a ticket gate process based on the ticket gate information. For example, the control device 14 determines whether or not the user is allowed to pass through the passage 15 based on the ticket gate information, and controls the operation of the door 12 based on the determination result. The control device 14 does not operate the door 12 when allowing the user to pass through the passage 15 and operates the door 12 so as to close the passage 15 when not permitting the user to pass through the passage 15.

  Next, the human body communication device 13 according to an embodiment will be described in detail with reference to FIGS.

  FIG. 2 is an explanatory diagram for explaining a configuration example of a control system of the human body communication device 13.

  The human body communication device 13 includes a first electrode unit 31, a human body communication circuit unit 32, a power circuit unit 33, a filter circuit unit 34, an inverting amplifier unit 35, a photocoupler 36, a current limiting unit 37, and a second electrode unit 38. Is provided.

  The first electrode unit 31 is an electrode used for human body communication via a human body. The first electrode unit 31 detects a signal propagating through the human body. The first electrode unit 31 is configured as an antenna, for example. The first electrode unit 31 can transmit and receive signals having a plurality of frequencies including at least a frequency (first frequency) used for human body communication via a human body. The 1st electrode part 31 is comprised by the wiring pattern on a board | substrate, for example.

  The human body communication circuit unit 32 is a human body communication processing unit that performs signal processing related to human body communication using the first electrode unit 31. The detailed configuration of the human body communication circuit unit 32 will be described later.

  The power supply circuit unit 33 supplies power to each unit of the human body communication device 13. For example, the power supply circuit unit 33 supplies AC power from a commercial power supply to at least the human body communication circuit unit 32 and the inverting amplifier unit 35. The power supply circuit unit 33 converts, for example, an alternating voltage from a commercial power supply into a power supply voltage used in each of the human body communication circuit unit 32 and the inverting amplifier unit 35 and supplies the same. The power supply circuit unit 33 is configured as an AC adapter including an AC / DC converter, for example.

  The filter circuit unit 34 is a filter that cuts a voltage signal having a specific frequency component from the voltage signal generated in the first electrode unit 31. More specifically, the filter circuit unit 34 extracts a signal obtained by cutting the first frequency signal used for human body communication from the voltage signal generated in the first electrode unit 31 and supplies the extracted signal to the inverting amplifier unit 35. . Thereby, the filter circuit unit 34 extracts a frequency component corresponding to noise from the commercial power source induced in the human body. For example, the filter circuit unit 34 may be configured by a passive circuit such as a resistor, an inductor, or a capacitor, or may be configured by an active circuit using an operational amplifier.

The inverting amplifier unit 35 generates a cancel signal for canceling noise flowing through the human body. The inverting amplifier unit 35 is a circuit that inverts the output waveform of the filter circuit unit 34, adjusts (amplifies) the inverted waveform, and outputs it to the photocoupler 36. That is, the inverting amplifier unit 35 functions as a phase inverting unit that supplies the photocoupler 36 with a signal obtained by inverting the phase of the signal excluding the first frequency signal by the filter circuit unit 34.
The inverting amplifier unit 35 can be composed of, for example, an operational amplifier or a transistor. The inverting amplifier unit 35 generates a cancel signal by inverting the phase of the signal supplied from the filter circuit unit 34 (that is, shifting the phase by 180 °) and amplifying the signal with a predetermined amplification factor. The filter circuit unit 34 and the inverting amplifier unit 35 may be configured by a single operational amplifier.

  The photocoupler 36 is a module for outputting the cancel signal output from the inverting amplifier unit 35 to the second electrode unit 38. The photocoupler 36 can supply a cancel signal to the second electrode unit 38 while being electrically insulated from the first electrode side. The photocoupler 36 receives the cancel signal output from the inverting amplifier unit 35 and the current corresponding to the impedance of the current limiting unit 37, and the current having the intensity corresponding to the input current is electrically insulated from the input side. Output from the output side to the second electrode unit 38. The filter circuit unit 34, the inverting amplifier unit 35, and the photocoupler 36 have a frequency (second frequency) other than the first frequency that is a communication frequency among signals detected by the first electrode unit 31. It functions as a cancel signal generation unit that generates a cancel signal for canceling the signal.

  The current limiting unit 37 is a circuit for limiting the current flowing through the photocoupler 36. The current limiting unit 37 varies the current that flows according to the control signal. Specifically, the current limiting unit 37 limits the current flowing through the photocoupler 36 according to the noise intensity that changes according to the environment in which the human body communication device 13 is used. The current limiting unit 37 limits the current flowing through the photocoupler 36 according to the control of the human body communication circuit unit 32, for example. That is, the current limiting unit 37 limits the intensity of the cancel signal supplied from the photocoupler 36 to the second electrode unit 38 according to the noise intensity estimated by the human body communication circuit unit 32. The current limiting unit 37 may be configured by a circuit using, for example, a resistor, an inductor, or a capacitor, may be configured by a circuit using a bipolar transistor or a field effect transistor, or the resistance value is set by setting. You may comprise using the digital potentiometer etc. which can be changed.

  The second electrode unit 38 is an electrode for applying a cancel signal to the human body. The second electrode unit 38 is configured as an antenna, for example. The second electrode unit 38 is configured by, for example, a wiring pattern on the substrate. The second electrode unit 38 generates an electromagnetic field according to the cancel signal supplied from the photocoupler 36, and generates an induced current according to the cancel signal in the human body. Thereby, the 2nd electrode part 38 can send the cancellation signal for canceling the noise except the frequency used for communication among the signals which propagate a human body to a human body. The second electrode unit 38 is preferably configured to surround the first electrode unit 31, for example. By configuring the second electrode unit 38 in this manner, it is possible to prevent the cancel signal from flowing through the human body due to the positional relationship between the human body communication device 13 and the human body.

  FIG. 3 is an explanatory diagram for explaining a configuration example of the human body communication circuit unit 32. The human body communication circuit unit 32 includes a control unit 41, a signal transmission unit 42, and a signal reception unit 43.

  The control unit 41 controls the operation of the human body communication circuit unit 32. The detailed configuration of the control unit 41 will be described later.

  The signal transmission unit 42 processes a communication signal transmitted from the human body communication circuit unit 32 to the external device via the first electrode unit 31, and transmits the processed communication signal to the external device. The detailed configuration of the signal transmission unit 42 will be described later.

  The signal receiving unit 43 receives and processes a communication signal input from the external device to the human body communication device 13 via the first electrode unit 31. A detailed configuration of the signal receiving unit 43 will be described later.

  FIG. 4 is an explanatory diagram for describing a configuration example of the signal transmission unit 42. The signal transmission unit 42 includes a digital / analog (D / A) conversion unit 51, a transmission filter unit 52, and a current limiting unit 53.

  The D / A converter 51 converts a digital signal into an analog signal. The D / A converter 51 converts the data supplied from the controller 41 into an analog signal.

  The transmission filter unit 52 performs signal processing on the analog signal converted by the D / A conversion unit 51. For example, the transmission filter unit 52 performs a filtering process for attenuating a signal of a predetermined frequency band of an analog signal. Further, the transmission filter unit 52 may be configured to adjust the frequency characteristic of the intensity of the analog signal to a preset characteristic, for example.

  The current limiting unit 53 performs processing on the analog signal that has been subjected to signal processing by the transmission filter unit 52 based on the control of the control unit 41, and passes the processed analog signal through the first electrode unit 31. Propagate to the human body. The current limiting unit 53 performs processing so that the analog signal is equal to or lower than a preset amperage on the human body.

  FIG. 4 is an explanatory diagram for explaining a configuration example of the signal receiving unit 43. The signal transmission unit 42 receives a communication signal transmitted from an external device such as the human body communication device 13 to the human body communication device 13 via the human body and the first electrode unit 31. For example, the signal receiving unit 43 acquires a communication signal by measuring a voltage induced in the first electrode unit 31 in accordance with an electric field generated by a communication signal propagating through a human body. The signal receiving unit 43 includes an analog / digital (A / D) conversion unit 61 and a signal processing unit 62.

  The A / D converter 61 converts the analog signal supplied from the signal processor 62 into a digital signal. The A / D converter 61 supplies the digital signal to the controller 41.

  The signal processing unit 62 performs signal processing on the analog signal supplied from the first electrode unit 31. The signal processing unit 62 supplies the analog signal subjected to the signal processing to the A / D conversion unit 61. The signal processing unit 62 includes at least one voltage amplification unit 63 and at least one reception filter unit 64.

  The voltage amplification unit 63 amplifies the analog signal supplied from the first electrode unit 31. That is, the voltage amplification unit 63 amplifies the voltage induced in the first electrode unit 31 according to the electric field generated by the communication signal propagating through the human body. The voltage amplifying unit 63 may be configured to amplify the voltage with a preset amplification degree, or may be configured to vary the amplification degree based on the control of the control unit 41. Further, the voltage amplifying unit 63 may include a voltage follower circuit having an amplification degree of 1.

  The reception filter unit 64 performs a filtering process for attenuating a signal in a predetermined frequency band of the analog signal supplied from the first electrode unit 31. For example, the reception filter unit 64 may be configured to adjust the frequency characteristic of the intensity of the analog signal to a preset characteristic. The reception filter unit 64 may be configured to include a circuit in which passive elements such as a resistor, an inductor, and a capacitor are combined, or may be configured by an active element such as an operational amplifier that operates based on the control of the control unit 41. The structure provided with an active filter may be sufficient.

  FIG. 5 is an explanatory diagram for explaining a configuration example of the control unit 41. The control unit 41 generates a digital signal to be transmitted, analyzes the received digital signal, and writes / reads data to / from the storage area. Further, the control unit 41 controls operations of the signal transmission unit 42 and the signal reception unit 43. The control unit 41 can propagate a communication signal corresponding to the digital signal to the human body by inputting the digital signal to the signal transmission unit 42. Moreover, the control part 41 can acquire the data transmitted from the other apparatus via the human body by analyzing the digital signal received from the signal receiving part 43.

  The control unit 41 is configured by a microcontroller having a storage area such as a flash memory or an EEPROM (registered trademark) (Electrically Erasable Programmable Read-Only Memory). Moreover, the control part 41 may be comprised by FPGA (Field Programmable Gate Array), PLD (Programmable Logic Device), etc., for example.

  As shown in FIG. 6, the control unit 41 includes an operation control unit 71, a communication signal calculation unit 72, and a noise estimation unit 73.

  The operation control unit 71 performs numerical calculations and calculations for communication control. That is, the operation control unit 71 generates a digital signal to be transmitted, analyzes the digital signal supplied from the signal receiving unit 43, and writes / reads data to / from the storage area. The operation control unit 71 can be implemented as a program in the microcontroller. For example, when the control unit 41 is configured by FPGA or PLD, the operation control unit 71 may be configured by a logic circuit that performs an operation equivalent to the above program. Further, the operation control unit 71 may be configured by providing the control unit 41 with a circuit that performs a microcontroller operation.

  The communication signal calculation unit 72 performs encoding, decoding, error correction processing, scrambling processing, interleaving processing, and the like on the digital signal when transmission / reception is performed. Since the first electrode unit 31 is configured to support both wireless communication and human body communication, that is, the first electrode unit 31 is shared by wireless communication and human body communication, one surface is a conductor. The efficiency of the first electrode unit 31 is lower than that of the antenna configured as described above. For this reason, the signal strength of the analog signal acquired by the first electrode unit 31 is reduced. For this reason, the communication signal calculation unit 72 improves the signal-to-noise ratio of the signal by using a convolutional code, a turbo code, a low density parity check code (LDPC code), or the like as an error correction code in communication processing. The communication signal calculation unit 72 is a physical layer of a communication method such as ITU-T G.9902, ITU-TG.9903, and ITU-T G.9907, which are communication standards for power line communication (PLC). Based on the specifications, processing such as the above-described encoding, decoding, error correction processing, scrambling processing, and interleaving processing is executed.

  The noise estimation unit 73 estimates the noise intensity based on the signal detected by the first electrode unit 31. For example, the noise estimation unit 73 estimates the intensity of noise caused by the commercial power supply in the signal detected by the first electrode unit 31. The noise estimation unit 73 controls the impedance of the current limiting unit 37 according to the estimated noise intensity. That is, the noise estimation unit 73 controls the intensity of the cancel signal supplied from the photocoupler 36 to the second electrode unit 38 according to the estimated noise intensity. The noise estimation unit 73 can perform estimation using, for example, fast Fourier transform (FFT) based on the time series data of the signal detected by the first electrode unit 31. The noise estimation unit 73 may be configured by software or hardware.

  As described above, the human body communication device 13 according to the embodiment includes the first electrode unit 31 that detects a signal propagating through the human body, and signals other than the first frequency among the signals detected by the first electrode unit 31. A cancel signal generation unit that generates a cancel signal for canceling a frequency signal, and a second electrode unit 38 that applies the cancel signal to the human body are provided. Thereby, the human body communication apparatus 13 is a signal of a frequency (second frequency) other than the first frequency that becomes noise with respect to the first frequency used for human body communication among the signals of a plurality of frequencies propagating through the human body. Can be canceled by a cancel signal. As a result, the human body communication device 13 can suppress the influence of noise and improve the communication performance.

  In addition, the human body communication device 13 according to the embodiment includes a photocoupler 36 for transmitting a cancel signal to the second electrode unit 38 as a part of the cancel signal generation unit. Thereby, the second electrode unit 38 is configured in a state of being electrically insulated from other circuits. Thereby, the influence from the commercial power supply with respect to the 2nd electrode part 38 side can be suppressed.

  In addition, the human body communication device 13 according to the embodiment estimates the noise intensity by the noise estimation unit 73 based on the signal detected by the first electrode unit 31, and outputs from the photocoupler 36 according to the estimated noise intensity. The intensity of the cancel signal supplied to the second electrode unit 38 is limited. As a result, the cancel signal can be applied to the human body with an intensity corresponding to the intensity of the noise actually generated.

  In general, in a human body communication apparatus, the closer the frequency used for communication and the frequency of the AC power supply that supplies power to the human body communication apparatus are, the greater the influence of noise caused by the AC power supply becomes. Therefore, the human body communication device 13 generates a cancel signal by the cancel signal generation unit when the first frequency used for communication is equal to or higher than a preset value, and the cancel signal to the human body by the second electrode unit 38. The structure which applies may be sufficient. In general, a commercial power source of 50 Hz to 60 Hz is used as an AC power source. For this reason, for example, the human body communication device 13 may be configured to switch between a state where the cancellation signal is applied and a state where the cancellation signal is not applied, with 1 MHz as a threshold.

  In the above-described embodiment, an example in which the photocoupler 36 is used as a configuration for supplying an input-side signal to the output side in an electrically insulated state is described, but the present invention is not limited to this configuration. The human body communication device 13 may include a pair of transformers that are magnetically connected to the input side and the output side instead of the photocoupler 36.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Entrance / exit management system, 2 ... Human body communication apparatus, 3 ... Entrance / exit management apparatus, 11 ... Housing | casing, 12 ... Door, 13 ... Human body communication apparatus, 14 ... Control apparatus, 31 ... 1st electrode part, 32 ... Human body communication circuit unit 33 ... Power supply circuit unit 34 ... Filter circuit unit 35 ... Inverting amplifier unit 36 ... Photo coupler 37 ... Current limiting unit 38 ... Second electrode unit 41 ... Control unit 42 ... Signal Transmission unit 43... Signal reception unit 71... Operation control unit 72 .. communication signal calculation unit 73.

Claims (6)

A first electrode for detecting a signal propagating through the human body;
A cancel signal generating unit that generates a cancel signal for canceling a signal having a frequency other than the communication frequency among the signals detected by the first electrode unit;
A second electrode for applying the cancel signal to the human body;
A human body communication device comprising:   The human body communication apparatus according to claim 1, wherein the cancel signal generation unit includes a photocoupler for transmitting the cancel signal to the second electrode unit. The cancellation signal generator is
A filter that removes the signal of the communication frequency from the signal detected by the first electrode unit;
A phase inversion unit that supplies a signal obtained by inverting the phase of the signal excluding the signal of the communication frequency by the filter to the photocoupler;
The human body communication device according to claim 2, further comprising: A human body communication processing unit for performing signal processing based on a signal detected by the first electrode unit;
A power supply unit that supplies power supplied from a commercial power supply to at least the human body communication processing unit and the phase inversion unit;
The human body communication device according to claim 3, further comprising: A noise estimation unit for estimating a noise intensity based on a signal detected by the first electrode unit;
A current limiting unit that limits the intensity of the cancellation signal supplied from the photocoupler to the second electrode unit according to the noise intensity estimated by the noise estimation unit;
The human body communication device according to claim 2, further comprising: A first electrode unit for detecting a signal propagating through the human body; a cancel signal generating unit for generating a cancel signal for canceling a signal having a frequency other than the communication frequency among the signals detected by the first electrode unit; A human body communication unit comprising: a second electrode unit that applies the cancel signal to the human body;
A ticket gate information acquisition unit for acquiring ticket gate information based on a signal detected by the human body communication unit;
A traffic determination unit that performs traffic determination based on the ticket gate information acquired by the ticket gate information acquisition unit;
An entrance / exit management device.