WO2021241456A1

WO2021241456A1 - Wireless sensor device, wireless communication system, and wireless communication method

Info

Publication number: WO2021241456A1
Application number: PCT/JP2021/019446
Authority: WO
Inventors: 秀樹桝田屋; 和宣大城
Original assignee: アルプスアルパイン株式会社
Priority date: 2020-05-25
Filing date: 2021-05-21
Publication date: 2021-12-02
Also published as: JP7402328B2; JPWO2021241456A1

Abstract

This wireless sensor device comprises: an antenna; a demodulation unit which demodulates a carrier wave received by the antenna; a sensor unit which emits a signal of a frequency which changes according to a measured value from a sensor; a storage unit which stores prescribed information; a modulation unit which modulates the carrier wave and supplies the modulated carrier wave to the antenna; and a control unit that, on the basis of a mode switching command included in the carrier wave received by the antenna, switches between a first mode, in which a carrier wave modulated by the modulation unit on the basis of a signal based on the prescribed information stored in the storage unit is transmitted from the antenna, and a second mode, in which the carrier wave modulated by the modulation unit on the basis of the frequency of the signal emitted by the sensor unit is transmitted from the antenna.

Description

Wireless sensor device, wireless communication system and wireless communication method

The present invention relates to a wireless sensor device, a wireless communication system, and a wireless communication method.

Conventionally, as a communication device that does not require a drive power supply, a device that employs an individual identification method (RFID: Radio Frequency IDentification) by radio waves and an oscillator type sensor are known. The oscillator type sensor excites the oscillator with a signal received from an external device, and then transmits a signal related to the resonance frequency of the oscillator that changes according to the capacitance of the sensor, so that the sensor value of the sensor by the external device is transmitted. It enables the estimation of. The following Patent Document 1 discloses a configuration in which an RFID and an oscillator type sensor are combined.

Japanese Unexamined Patent Publication No. 2010-154195

However, the technique of Patent Document 1 is to modulate the response signal from the RFID by the subcarrier that the oscillator emits (ASK: Amplitude Shift Keying). Therefore, in the technique of Patent Document 1, it is necessary to share the energy of the same carrier wave between the RFID and the vibrator. Therefore, there is a possibility that sufficient power is not supplied for the sensor to operate, or the signal strength of the reply wave is lowered. Therefore, the technique of Patent Document 1 cannot obtain both the advantage of the configuration in which the measured values of the sensors are individually transmitted and the advantage of the configuration in which the predetermined information stored in the storage unit is individually transmitted.

Therefore, the purpose is to obtain both the advantage of the configuration in which the measured values of the sensors are individually transmitted and the advantage of the configuration in which the predetermined information stored in the storage unit is individually transmitted.

The wireless sensor device according to one embodiment stores predetermined information: an antenna, a demodulator that demolishes a carrier wave received by the antenna, a sensor unit that emits a signal having a frequency that changes according to a measured value of the sensor, and a predetermined information. Based on the storage unit, the modulation unit that modulates the carrier wave and supplies the modulated carrier wave to the antenna, and the mode switching command included in the carrier wave received by the antenna, based on predetermined information stored in the storage unit. The first mode in which the carrier wave modulated by the modulator based on the signal is transmitted from the antenna, and the second mode in which the carrier wave modulated by the modulator based on the frequency of the signal emitted by the sensor unit is transmitted from the antenna. It is provided with a control unit for switching between and.

Further, the wireless communication system according to the embodiment includes a wireless sensor device and a transmitter / receiver for transmitting / receiving a carrier wave to / from the wireless sensor device.

Further, the wireless communication method according to the embodiment is wireless by a wireless sensor device including an antenna, a sensor unit that emits a signal having a frequency that changes according to a measured value of the sensor, and a storage unit that stores predetermined information. In the communication method, the operation mode of the wireless sensor device is set to the first mode and the first mode based on the demodulation step of demolishing the carrier wave received by the antenna and the mode switching command included in the carrier wave demolished in the demolishing step. A switching step of switching between the two modes, a first modulation step of modulating the carrier wave based on a signal based on predetermined information in the first mode, and supplying the modulated carrier wave to the antenna, and a second mode. The mode includes a second modulation step of modulating the carrier wave based on the frequency of the signal emitted by the sensor unit and supplying the modulated carrier wave to the antenna.

According to one embodiment, it is possible to obtain both the advantage of the configuration in which the measured values of the sensors are individually transmitted and the advantage of the configuration in which the predetermined information stored in the storage unit is individually transmitted.

Configuration diagram of the wireless communication system according to the first embodiment A flowchart showing a procedure of processing by the wireless sensor device according to the first embodiment. The figure which shows the state of the "first mode" of the wireless sensor apparatus which concerns on 1st Embodiment. The figure which shows the state of the "second mode" of the wireless sensor apparatus which concerns on 1st Embodiment. The figure which shows the state of the "second mode" of the wireless sensor apparatus which concerns on 1st Embodiment. Configuration diagram of the wireless communication system according to the second embodiment A flowchart showing a procedure of processing by the wireless sensor device according to the second embodiment. The figure which shows the state of the "first mode" of the wireless sensor apparatus which concerns on 2nd Embodiment The figure which shows the state of the "second mode" of the wireless sensor apparatus which concerns on 2nd Embodiment

Hereinafter, one embodiment will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a configuration diagram of a wireless communication system 10 according to the first embodiment. The wireless communication system 10 shown in FIG. 1 includes a wireless sensor device 100 and a transmitter / receiver 200. When the wireless communication system 10 is installed in a vehicle such as an automobile, the wireless sensor device 100 measures the state of the vehicle (for example, the air pressure of the tire), and the measurement result of the state of the vehicle is transmitted and received from the wireless sensor device 100. It is a system capable of wirelessly transmitting to the machine 200.

As shown in FIG. 1, the wireless sensor device 100 includes an antenna 101, a charging unit 102, a circuit unit 110, and a sensor unit 120.

The antenna 101 receives a carrier wave in a predetermined frequency band (for example, 2.4 GHz band) transmitted from the transmitter / receiver 200. Further, the antenna 101 transmits the carrier wave modulated by the modulation unit 117 of the circuit unit 110 to the transmitter / receiver 200.

The sensor unit 120 includes a sensor 121 and a vibrator 122. The sensor 121 is connected in parallel to the oscillator 122, and the capacitance changes according to the measured value. As the sensor 121, for example, a pressure sensor for measuring the air pressure of a vehicle tire is used. The oscillator 122 is excited by applying an excitation signal included in the carrier wave received by the antenna 101. Therefore, the frequency of the excitation signal is substantially equal to the natural frequency of the vibrator 122. When the carrier wave including the excitation signal is first received, the oscillator 122 excites in the vicinity of the resonance frequency of the circuit composed of the oscillator 122 and the sensor 121 based on the excitation signal. After that, when the excitation by the carrier wave is stopped, the vibrator 122 damps and vibrates at the resonance frequency of the circuit composed of the vibrator 122 and the sensor 121 in a short echoic period of, for example, about 1 msec. The resonance frequency at which the oscillator 122 damped and vibrates changes according to the capacitance of the sensor 121. That is, the resonance frequency at which the vibrator 122 damps and vibrates changes according to the measured value of the sensor 121. As a result, the sensor unit 120 emits a signal having a frequency corresponding to the measured value of the sensor 121. The signal emitted from the sensor unit 120 is supplied to the modulation unit 117 of the circuit unit 110.

The circuit unit 110 includes a storage unit 111, a demodulation unit 112, a power generation unit 113, a voltage control unit 114, a control unit 116, a timer 115, and a modulation unit 117.

The storage unit 111 stores predetermined information. For example, the storage unit 111 stores ID information, calibration information of the sensor 121, etc., which are unique to the wireless sensor device 100, as predetermined information. The calibration information of the sensor 121 is information for calibrating the variation of the measured value of the sensor 121, and examples thereof include information on a reference table and information on coefficients used in the calibration formula. The storage unit 111 includes, for example, a non-volatile memory.

The demodulation unit 112 demodulates the carrier wave received by the antenna 101. As a result, the demodulation unit 112 extracts the original signal before modulation from the carrier wave.

The power generating unit 113 uses the energy of the carrier wave received by the antenna 101 to generate DC power. The power generating unit 113 includes, for example, an RF-DC conversion circuit.

The voltage control unit 114 charges the charging unit 102 with the DC power generated by the power generating unit 113. Further, the voltage control unit 114 supplies the electric power charged in the charging unit 102 to the control unit 116 and the like. The charging unit 102 includes, for example, a capacitor.

The timer 115 measures a certain period of time during which the control unit 116 waits in the "second mode".

The control unit 116 controls the entire wireless sensor device 100. For example, when the signal extracted from the carrier wave by the demodulation unit 112 includes a mode switching command, the control unit 116 sets the operation mode of the wireless sensor device 100 to "first mode" based on the mode switching command. To "second mode". The "first mode" is an operation mode in which the carrier wave is modulated by a signal based on predetermined information stored in the storage unit 111, and the modulated carrier wave is transmitted to the transmitter / receiver 200 via the antenna 101. .. That is, the "first mode" is an operation mode in which predetermined information is included in the carrier wave and transmitted to the transmitter / receiver 200. The "second mode" is an operation mode in which the carrier wave is modulated by the frequency of the signal emitted by the sensor unit 120, and the modified carrier wave is transmitted to the transmitter / receiver 200 via the antenna 101. That is, the "second mode" is an operation mode in which the measured value of the sensor 121 is included in the carrier wave and transmitted to the transmitter / receiver 200.

The modulation unit 117 modulates the carrier wave received by the antenna 101, and supplies the modulated carrier wave to the antenna 101. In the "first mode", the modulation unit 117 modulates the carrier wave based on the signal based on the predetermined information stored in the storage unit 111. As a result, the carrier wave after modulation contains predetermined information. In the "second mode", the modulation unit 117 modulates the carrier wave based on the frequency of the signal emitted by the sensor unit 120. As a result, the carrier wave after modulation includes the measured value of the sensor 121. The modulation unit 117 includes, for example, a switching element such as a field effect transistor (FET).

Further, the circuit unit 110 includes a switch SW1 (first switch), a switch SW2 (second switch), a switch SW3 (third switch), and a switch SW4 (fourth switch). The switch SW1 is provided between the demodulation unit 112 and the control unit 116. The switch SW2 is provided between the demodulation unit 112 and the sensor unit 120. The switch SW3 is provided between the sensor unit 120 and the modulation unit 117. The switch SW4 is provided between the antenna 101 and the power generating unit 113. The switching operation between "ON" and "OFF" of each of the switches SW1 to SW4 is controlled by the control unit 116. As each of the switches SW1 to SW4, for example, a FET (Field effect transistor) is used. In the following, an example will be described in which a so-called normally-on switch, which is turned “ON” when not driven, is used as the switches SW1 and SW4. Further, an example will be described in which a so-called normally off switch, which is “OFF” when not driven, is used as the switches SW2 and SW3. The switch SW1 is not limited to the normally on switch, and the switches SW2 and SW3 are not limited to the normally off switch. Further, the switch SW4 needs to be a normally-on switch in order to execute step S201 described later, but even if the switch SW4 is not provided and the antenna 101 and the power generating unit 113 are always energized. good.

FIG. 2 is a flowchart showing a processing procedure by the wireless sensor device 100 according to the first embodiment.

First, the power generating unit 113 generates electric power from the carrier wave received from the antenna 101, and the voltage control unit 114 charges the charging unit 102 with the generated electric power (step S201). Next, the voltage control unit 114 determines whether or not the voltage of the electric power charged in the charging unit 102 has reached an appropriate value (step S202). If it is determined in step S202 that the voltage of the electric power charged in the charging unit 102 is not an appropriate value (step S202: No), the voltage control unit 114 executes step S202 again.

On the other hand, in step S202, when it is determined that the voltage of the electric power charged in the charging unit 102 has reached an appropriate value (step S202: Yes), the control unit 116 switches the switch SW1 to ON and the switch SW2 to OFF. Switching, switching the switch SW3 to OFF (step S203 (switching step)). However, when the switch SW1 is a normally on switch and the switches SW2 and SW3 are normally off switches, it is not necessary to switch these switches for the first time.

Next, the demodulation unit 112 demodulates the carrier wave received by the antenna 101 (step S204 (demodulation step)). As a result, the signal including the original instruction extracted from the carrier wave is supplied to the control unit 116A.

Next, the control unit 116 determines whether or not the signal extracted from the carrier wave by the demodulation unit 112 includes a mode switching command (step S205).

If it is determined in step S205 that the mode switching command is not included (step S205: No), the wireless sensor device 100 operates in the "first mode" and executes the processes of steps S206 to S209.

In the "first mode", first, the control unit 116 supplies a signal based on the predetermined information stored in the storage unit 111 to the modulation unit 117 (step S206).

Then, the modulation unit 117 modulates the carrier wave transmitted by the antenna 101 based on the signal based on the supplied predetermined information (step S207 (first modulation step)).

Further, the modulation unit 117 supplies the modulated carrier wave to the antenna 101 (step S208). As a result, the antenna 101 transmits the modulated carrier wave to the transmitter / receiver 200 (step S209). After that, the wireless sensor device 100 returns the process to step S201.

On the other hand, when it is determined in step S205 that the mode switching command is included (step S205: Yes), the wireless sensor device 100 operates in the "second mode" and executes the processes of steps S210 to S217. do.

In the "second mode", first, the control unit 116 switches the switch SW1 to OFF and the switch SW2 to ON (step S210 (switching step)). As a result, the demodulation unit 112 and the sensor unit 120 are connected, and the signal output from the demodulation unit 112 is supplied to the sensor unit 120. As a result, the excitation of the vibrator 122 included in the sensor unit 120 is started (step S211).

Then, the control unit 116 waits for a certain period of time (first predetermined time) (step S212). The first predetermined time is a time sufficient for the vibrator 122 to be excited by the excitation signal supplied from the demodulation unit 112 to the sensor unit 120. The first predetermined time is measured by the timer 115.

Then, when the first predetermined time elapses, the control unit 116 switches the switch SW2 to OFF and the switch SW3 to ON (step S213). As a result, the sensor unit 120 and the modulation unit 117 are connected, and the signal emitted from the sensor unit 120 is supplied to the modulation unit 117.

Then, the modulation unit 117 modulates the carrier wave transmitted by the antenna 101 based on the frequency of the supplied signal (step S214 (second modulation step)).

Further, the modulation unit 117 supplies the modulated carrier wave to the antenna 101 (step S215). As a result, the antenna 101 transmits the modulated carrier wave to the transmitter / receiver 200 (step S216). After that, the wireless sensor device 100 waits for a certain period of time (second predetermined time) (step S217), and then returns the process to step S201.

FIG. 3 is a diagram showing a state of the "first mode" of the wireless sensor device 100 according to the first embodiment. As shown in FIG. 3, in the wireless sensor device 100, each of the switches SW1 to SW4 is in a non-driving state in the "first mode". That is, the switches SW1 and SW4 are "ON", and the switches SW2 and SW3 are "OFF".

As a result, in the wireless sensor device 100, in the "first mode", as shown in FIG. 3, the antenna 101 and the power generating unit 113 are connected, and the carrier wave received by the antenna 101 is transmitted to the power generating unit 113. It is supplied (arrow A1 in the figure). Then, the DC power generated by the power generating unit 113 is charged to the charging unit 102 via the voltage control unit 114.

Further, in the wireless sensor device 100, as shown in FIG. 3, in the "first mode", the demodulation unit 112 and the control unit 116 are connected, and the signal output from the demodulation unit 112 (modulation taken out from the carrier wave). The previous original signal) is supplied to the control unit 116 (arrow A2 in the figure).

The control unit 116 supplies a signal based on predetermined information stored in the storage unit 111 to the modulation unit 117 in response to receiving the signal (arrow A3 in the figure). As a result, the modulated carrier wave based on the predetermined information (that is, the carrier wave including the predetermined information) is supplied from the modulation unit 117 to the antenna 101 (arrow A4 in the figure). The antenna 101 transmits the modulated carrier wave supplied from the modulation unit 117 to the transmitter / receiver 200. The signal based on the predetermined information may be the predetermined information itself, or may be a signal generated by performing some processing on the predetermined information (for example, a random number for encryption). good.

4 and 5 are diagrams showing the state of the “second mode” of the wireless sensor device 100 according to the first embodiment. When the signal received in the "first mode" includes a mode switching command to the "second mode", the control unit 116 of the wireless sensor device 100 sets the operation mode of the wireless sensor device 100 to "the second mode". Switch to "mode 2".

Specifically, as shown in FIG. 4, the control unit 116 switches the switch SW1 to OFF and the switch SW2 to ON. As a result, as shown in FIG. 4, the demodulation unit 112 and the sensor unit 120 are connected, and the signal output from the demodulation unit 112 is supplied to the sensor unit 120 (arrow B1 in the figure). In the sensor unit 120, by supplying a signal to the vibrator 122, the vibrator 122 first excites near the resonance frequency of the circuit composed of the vibrator 122 and the sensor 121, and then the signal When the supply is cut off, the signal is attenuated and vibrated at the resonance frequency of the circuit composed of the oscillator 122 and the sensor 121, so that a signal having the same frequency as the resonance frequency of the circuit composed of the oscillator 122 and the sensor 121 is generated. Emit. The oscillator 122 emits a signal having a frequency corresponding to the measured value of the sensor 121.

When the first predetermined time has elapsed after switching the switches SW1 and SW2 in the "second mode", the control unit 116 switches the switch SW2 to OFF and switches the switch SW3 to OFF, as shown in FIG. Switch to ON. As a result, as shown in FIG. 5, the sensor unit 120 and the modulation unit 117 are connected, and the signal emitted from the sensor unit 120 is supplied to the modulation unit 117 (arrow B2 in the figure).

As a result, the modulated carrier wave (that is, the carrier wave including the measured value of the sensor 121) based on the frequency of the signal emitted from the sensor unit 120 is supplied from the modulation unit 117 to the antenna 101 (arrow B3 in the figure). The antenna 101 transmits the modulated carrier wave supplied from the modulation unit 117 to the transmitter / receiver 200.

The control unit 116 causes the power generation unit 113 to generate the electric power by turning on the fourth switch SW4 in the "first mode", and the power generation unit 113 in the "second mode". When the generated power exceeds a predetermined value, the fourth switch may be turned off. As a result, the wireless sensor device 100 according to the first embodiment transfers most of the energy of the carrier wave received by the antenna 101 via the demodulation unit 112 when sufficient power can be secured to supply the control unit 116. Can be supplied to the sensor unit 120. The control unit 116 can determine that, for example, when the voltage charged in the charging unit 102 becomes a predetermined value or more, the electric power generated by the power generating unit 113 becomes a predetermined value or more.

As described above, the wireless sensor device 100 according to the first embodiment includes an antenna 101, a demodulator 112 that demolishes a carrier wave received by the antenna 101, and a signal having a frequency that changes according to a measured value of the sensor 121. 120, a storage unit 111 that stores predetermined information, a modulation unit 117 that modulates the carrier wave and supplies the modulated carrier wave to the antenna 101, and mode switching included in the carrier wave received by the antenna 101. In the first mode in which the carrier wave modulated by the modulation unit 117 based on the signal based on the predetermined information stored in the storage unit 111 based on the command is transmitted from the antenna 101, and the signal emitted by the sensor unit 120. A control unit 116 for switching between a second mode in which a carrier wave modulated by the modulation unit 117 based on the frequency is transmitted from the antenna 101 and a control unit 116 is provided.

As a result, the wireless sensor device 100 according to the first embodiment transmits the measured value of the sensor 121 by the carrier wave and the predetermined information stored in the storage unit 111 in response to the mode switching command from the transmitter / receiver 200. Transmission by carrier wave can be selectively switched. Therefore, according to the wireless sensor device 100 according to the first embodiment, the advantage of the configuration of individually transmitting the measured value of the sensor 121 and the advantage of the configuration of individually transmitting the predetermined information stored in the storage unit 111. You can get both.

The transmitter / receiver 200 is compatible with the wireless sensor device 100. For example, the transmitter / receiver 200 transmits a carrier wave to the wireless sensor device 100. At this time, the transmitter / receiver 200 does not include the mode switching command in the carrier wave when acquiring predetermined information from the wireless sensor device 100. In this case, the transmitter / receiver 200 receives a carrier wave including predetermined information from the wireless sensor device 100. Therefore, the transmitter / receiver 200 can obtain predetermined information by demodulating the received carrier wave. On the other hand, when the transmitter / receiver 200 acquires the measured value of the sensor 121 from the wireless sensor device 100, the transmitter / receiver 200 includes a mode switching command in the carrier wave. In this case, the transmitter / receiver 200 receives the carrier wave including the measured value of the sensor 121 from the wireless sensor device 100. Therefore, the transmitter / receiver 200 can obtain the measured value of the sensor 121 by demodulating the received carrier wave and measuring its frequency. For example, the transmitter / receiver 200 acquires the identification information of the wireless sensor device 100 as predetermined information, and then transmits a carrier wave including a mode switching command to the wireless sensor device 100 corresponding to the identification information. The carrier wave including the measured value of the sensor 121 can be received only from the wireless sensor device 100 corresponding to the identification information.

[Second Embodiment]
Next, the second embodiment will be described. Hereinafter, changes from the first embodiment will be described with respect to the wireless communication system 10A according to the second embodiment.

FIG. 6 is a configuration diagram of the wireless communication system 10A according to the second embodiment. As shown in FIG. 6, the wireless communication system 10A according to the second embodiment includes a wireless sensor device 100A instead of the wireless sensor device 100. The wireless sensor device 100A includes a sensor unit 150 instead of the sensor unit 120. Further, the wireless sensor device 100A includes a control unit 116A instead of the control unit 116. Further, the wireless sensor device 100A does not have to have the switch SW2.

The sensor unit 150 includes a sensor 151 and an oscillator 152. The sensor 151 is connected to the oscillator 152. As the sensor 151, for example, a pressure sensor for measuring the air pressure of a vehicle tire is used. When the power supply voltage Vcc is supplied from the control unit 116A, the oscillator 152 self-oscillates at a frequency corresponding to the measured value of the sensor 151. As a result, the sensor unit 150 emits a signal having a frequency corresponding to the measured value of the sensor 151. The signal emitted from the sensor unit 150 is supplied to the modulation unit 117 of the circuit unit 110.

FIG. 7 is a flowchart showing a processing procedure by the wireless sensor device 100A according to the second embodiment.

First, the power generating unit 113 generates electric power from the carrier wave received from the antenna 101, and the voltage control unit 114 charges the charging unit 102 with the generated electric power (step S701). Next, the voltage control unit 114 determines whether or not the voltage of the electric power charged in the charging unit 102 has reached an appropriate value (step S702). If it is determined in step S702 that the voltage of the electric power charged in the charging unit 102 is not an appropriate value (step S702: No), the voltage control unit 114 executes step S702 again.

On the other hand, in step S702, when it is determined that the voltage of the electric power charged in the charging unit 102 has reached an appropriate value (step S702: Yes), the control unit 116A switches the switch SW1 to ON and the switch SW3 to OFF. Switching (step S703 (switching step)). However, when the switch SW1 is a normally on switch and the switch SW3 is a normally off switch, it is not necessary to switch these switches for the first time.

Next, the demodulation unit 112 demodulates the carrier wave received by the antenna 101 (step S704 (demodulation step)). As a result, the original signal extracted from the carrier wave is supplied to the control unit 116A.

Next, the control unit 116A determines whether or not the signal extracted from the carrier wave by the demodulation unit 112 includes a mode switching command (step S705).

If it is determined in step S705 that the mode switching command is not included (step S705: No), the wireless sensor device 100A operates in the "first mode" and executes the processes of steps S706 to S709.

In the "first mode", first, the control unit 116A supplies a signal based on the predetermined information stored in the storage unit 111 to the modulation unit 117 (step S706).

Then, the modulation unit 117 modulates the carrier wave transmitted by the antenna 101 based on the signal based on the supplied predetermined information (step S707 (first modulation step)).

Further, the modulation unit 117 supplies the modulated carrier wave to the antenna 101 (step S708). As a result, the antenna 101 transmits the modulated carrier wave to the transmitter / receiver 200 (step S709). After that, the wireless sensor device 100A returns the process to step S701.

On the other hand, when it is determined in step S705 that the mode switching command is included (step S705: Yes), the wireless sensor device 100A operates in the "second mode" and executes the processes of steps S710 to S716. do.

In the "second mode", first, the control unit 116A supplies the power supply voltage Vcc to the oscillator 152 of the sensor unit 150 (step S710). Then, after waiting for a certain period of time (step S711), the control unit 116A switches the switch SW3 to ON (step S712). As a result, the sensor unit 150 and the modulation unit 117 are connected, and the signal emitted from the sensor unit 150 is supplied to the modulation unit 117.

Then, the modulation unit 117 modulates the carrier wave transmitted by the antenna 101 based on the frequency of the supplied signal (step S713 (second modulation step)).

Further, the modulation unit 117 supplies the modulated carrier wave to the antenna 101 (step S714). As a result, the antenna 101 transmits the modulated carrier wave to the transmitter / receiver 200 (step S715). After that, the wireless sensor device 100A waits for a certain period of time (second predetermined time) (step S716), and then returns the process to step S701.

FIG. 8 is a diagram showing a state of the “first mode” of the wireless sensor device 100A according to the second embodiment. As shown in FIG. 8, in the wireless sensor device 100A, each of the switches SW1, SW3, and SW4 is in the non-driving state in the "first mode". That is, the switches SW1 and SW4 are turned "ON", and the switches SW3 are turned "OFF".

As a result, in the wireless sensor device 100A, in the "first mode", as shown in FIG. 8, the antenna 101 and the power generating unit 113 are connected, and the carrier wave received by the antenna 101 is transmitted to the power generating unit 113. It is supplied (arrow C1 in the figure). Then, the DC power generated by the power generating unit 113 is charged to the charging unit 102 via the voltage control unit 114.

Further, in the wireless sensor device 100A, as shown in FIG. 8, in the "first mode", the demodulation unit 112 and the control unit 116A are connected, and the signal output from the demodulation unit 112 (modulation taken out from the carrier wave). The previous original signal) is supplied to the control unit 116A (arrow C2 in the figure).

The control unit 116A supplies a signal based on predetermined information stored in the storage unit 111 to the modulation unit 117 in response to receiving the signal (arrow C3 in the figure). As a result, the modulated carrier wave based on the predetermined information (that is, the carrier wave including the predetermined information) is supplied from the modulation unit 117 to the antenna 101 (arrow C4 in the figure). The antenna 101 transmits the modulated carrier wave supplied from the modulation unit 117 to the transmitter / receiver 200.

FIG. 9 is a diagram showing a state of the "second mode" of the wireless sensor device 100A according to the second embodiment. When the signal received in the "first mode" includes a mode switching command to the "second mode", the control unit 116A of the wireless sensor device 100A sets the operation mode of the wireless sensor device 100A to "the first mode". Switch to "mode 2".

Specifically, as shown in FIG. 9, the control unit 116A supplies the power supply voltage Vcc to the oscillator 152 of the sensor unit 150 (arrow D1 in the figure). At this time, the control unit 116A can also switch the switch SW1 to OFF for a certain period of time and supply electric power by the power generation unit 113. As a result, the oscillator 152 self-oscillates at a frequency corresponding to the measured value of the sensor 151.

Then, the control unit 116A switches the switch SW3 to ON as shown in FIG. As a result, as shown in FIG. 9, the sensor unit 150 and the modulation unit 117 are connected, and the signal emitted from the sensor unit 150 is supplied to the modulation unit 117 (arrow D2 in the figure).

As a result, the modulated carrier wave (that is, the carrier wave including the measured value of the sensor 151) based on the frequency of the signal emitted from the sensor unit 150 is supplied from the modulation unit 117 to the antenna 101 (arrow D3 in the figure). The antenna 101 transmits the modulated carrier wave supplied from the modulation unit 117 to the transmitter / receiver 200.

As described above, the wireless sensor device 100A according to the second embodiment includes an antenna 101, a demodulator 112 that demolishes a carrier wave received by the antenna 101, and a signal having a frequency that changes according to a measured value of the sensor 151. 150, a storage unit 111 that stores predetermined information, a modulation unit 117 that modulates the carrier wave and supplies the modulated carrier wave to the antenna 101, and mode switching included in the carrier wave received by the antenna 101. Based on the first mode in which the carrier wave modulated by the modulation unit 117 based on the predetermined information stored in the storage unit 111 is transmitted from the antenna 101 based on the command, and the frequency of the signal emitted by the sensor unit 150. It is provided with a control unit 116A for switching between a second mode in which the carrier wave modulated by the modulation unit 117 is transmitted from the antenna 101.

As a result, the wireless sensor device 100A according to the second embodiment transmits the measured value of the sensor 151 by the carrier wave and the predetermined information stored in the storage unit 111 in response to the mode switching command from the transmitter / receiver 200. Transmission by carrier wave can be selectively switched. Therefore, according to the wireless sensor device 100A according to the second embodiment, the advantage of the configuration of individually transmitting the measured value of the sensor 151 and the advantage of the configuration of individually transmitting the predetermined information stored in the storage unit 111. You can get both.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to these embodiments, and various modifications or modifications are made within the scope of the gist of the present invention described in the claims. It can be changed.

This international application claims priority based on Japanese Patent Application No. 2020-090713 filed on May 25, 2020, and the entire contents of this application will be incorporated into this international application.

10, 10A

wireless communication system

100, 100A wireless sensor device 101 antenna 102 charging unit 110 circuit unit 111 storage unit 112 demographic unit 113 power generating unit 114 voltage control unit 115

timer

116, 116A control unit 117 modulation unit 120 sensor unit 121 sensor 122 Transducer 150 Sensor unit 151 Sensor 152 Oscillator 200 Transmitter / receiver SW1 to SW4 switch

Claims

With the antenna
A demodulator that demodulates the carrier wave received by the antenna,
A sensor unit that emits a signal with a frequency that changes according to the measured value of the sensor,
A storage unit that stores predetermined information and
A modulation unit that modulates the carrier wave and supplies the modulated carrier wave to the antenna.
Based on the mode switching command included in the carrier wave received by the antenna, the carrier wave modulated by the modulator based on the signal based on the predetermined information stored in the storage unit is transmitted from the antenna. A control unit for switching between a first mode for transmitting the carrier wave to be transmitted from the antenna and a second mode for transmitting the carrier wave modulated by the modulation unit based on the frequency of the signal emitted by the sensor unit is provided. Wireless sensor device.
The sensor unit is
A sensor whose capacity changes according to the measured value,
The wireless sensor device according to claim 1, further comprising an oscillator whose resonance frequency changes according to the capacitance of the sensor.
The wireless sensor device according to claim 2, wherein the excitation signal included in the carrier wave received by the antenna is supplied to the vibrator.
The sensor unit is
Sensors whose capacitance or resistance changes according to the measured value,
The wireless sensor device according to claim 1, further comprising an oscillator whose oscillation frequency changes according to the capacitance or resistance value of the sensor.
A first switch connected between the demodulation unit and the control unit,
A second switch connected between the demodulation unit and the sensor unit,
Further, a third switch connected between the sensor unit and the modulation unit is provided.
The control unit
In the first mode, the first switch is turned on and the second switch is turned off so that the signal output from the demodulation unit is supplied to the control unit.
In the second mode, by turning off the first switch, turning on the second switch, and turning off the third switch, the signal output from the demodulation unit is supplied to the sensor unit. Then, by turning off the second switch and turning on the third switch, the signal emitted from the sensor unit is supplied to the modulation unit. The wireless sensor device according to any one of 1 to 4.
An electromotive unit that generates electric power using the energy of the carrier wave received by the antenna, and
Further, a fourth switch connected between the antenna and the power generating unit is provided.
The control unit
In the first mode, by turning on the fourth switch, the power generating unit is made to generate the electric power.
The wireless sensor device according to claim 5, wherein in the second mode, when the electric power generated by the power generating unit becomes a predetermined value or more, the fourth switch is turned off.
The first switch is turned on in the non-driving state and is turned on.
The wireless sensor device according to claim 5 or 6, wherein the second switch is turned off in a non-driving state.
The wireless sensor device according to any one of claims 1 to 7, wherein the predetermined information includes identification information of the wireless sensor device.
The wireless sensor device according to any one of claims 1 to 8, wherein the predetermined information includes calibration information of the sensor.
The wireless sensor device according to any one of claims 1 to 9.
A wireless communication system including a transmitter / receiver for transmitting / receiving the carrier wave to the wireless sensor device.
The transmitter / receiver
After receiving the carrier wave modulated based on the signal based on the identification information of the wireless sensor device, which is the predetermined information, from the wireless sensor device, the wireless sensor device corresponding to the identification information is described. By transmitting the carrier wave including a mode switching command, the wireless sensor device corresponding to the identification information is characterized by receiving the carrier wave modulated based on the frequency of the signal emitted by the sensor unit. The wireless communication system according to claim 10.
A wireless communication method using a wireless sensor device including an antenna, a sensor unit that emits a signal having a frequency that changes according to a measured value of the sensor, and a storage unit that stores predetermined information.
A demodulation step of demodulating the carrier wave received by the antenna, and
A switching step of switching the operation mode of the wireless sensor device between the first mode and the second mode based on the mode switching command included in the carrier wave demodulated in the demodulation step.
In the first mode, the first modulation step of modulating the carrier wave based on the signal based on the predetermined information and supplying the modulated carrier wave to the antenna.
In the second mode, the radio includes a second modulation step of modulating the carrier wave based on the frequency of the signal emitted by the sensor unit and supplying the modulated carrier wave to the antenna. Communication method.