CN117792440A - Sensor, safety door switch and control method thereof - Google Patents

Abstract

The invention provides a sensor, a safety door switch and a control method thereof. The microprocessor is electrically connected with the antenna, the wireless transceiver chip and the reference voltage switching circuit module. And the microprocessor is used for controlling the starting of the reference voltage switching circuit module after the trigger is identified by induction, and adjusting the reference voltage for supplying power to the wireless transceiver chip so as to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, thereby adaptively adjusting the distance range for data interaction with the trigger. Compared with the prior art, the sensor, the safety door switch and the control method thereof can better solve the problem of how to stably identify and perform data interaction by the sensor when the trigger is close to the sensor.

Description

Sensor, safety door switch and control method thereof

Technical Field

The present disclosure relates to sensors, and particularly to a sensor, a safety door switch, and a control method thereof.

Background

In the prior art, RFID technology generally refers to radio frequency technology, and the technology mainly realizes two-way communication between devices by means of a magnetic field or electromagnetic field principle, thereby realizing a function of exchanging data. In a traditional door switch, the automatic coordination effect is poor because the modulation depth of a sensor reader-writer end is fixed, the stable identification effect is poor at a critical distance where data interaction can be carried out with a sensor, and the requirement of the process sensor industry for pursuing stability is not met.

Therefore, how to provide an RFID technology to better solve the technical problem of how to stably identify and perform data interaction by the sensor when the trigger approaches to the sensor is a technical problem to be solved in the invention.

Disclosure of Invention

The invention aims to provide a sensor, a safety door switch and a control method thereof, which are used for solving the technical problem of how to stably identify and perform data interaction by the sensor when a trigger approaches to the sensor.

In order to achieve the above object, the present invention proposes a sensor comprising:

an antenna;

a wireless transceiver chip electrically connected to the wireless transceiver chip;

a reference voltage switching circuit module;

an LC resonant circuit electrically connected to the wireless transceiver chip;

a microprocessor electrically connected to the antenna, the wireless transceiver chip, and the reference voltage switching circuit module;

the microprocessor is used for controlling the reference voltage switching circuit module to start after sensing and identifying an external trigger, and adjusting the reference voltage for supplying power to the wireless transceiver chip so as to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, thereby adaptively adjusting the distance range for carrying out data interaction with the trigger.

Further preferably, the reference voltage switching circuit module is configured to output two or more reference voltages, where the reference voltages at least include: a first reference voltage greater than the common voltage, at least one second reference voltage less than the common voltage; the common voltage is the voltage for supplying power to the wireless transceiver chip when the reference voltage switching circuit module is switched to the common voltage circuit or the reference voltage switching circuit module is closed by the reference voltage regulating circuit.

Further preferably, the reference voltage switching circuit module includes: a first switching circuit switch for regulating the reference voltage; the first switching circuit switch is electrically connected with the first signal output end of the microprocessor, and the other end of the first switching circuit switch is electrically connected with the wireless transceiver chip; the first switching circuit switch is used for enabling the wireless transceiver chip to be connected with the corresponding reference voltage regulating circuit in a conducting mode according to the received first signal.

Further preferably, the first switching circuit switch further includes: one end of the wireless transceiver chip is electrically connected with the second signal output end of the microprocessor, and the other end of the wireless transceiver chip is electrically connected with the second signal output end of the microprocessor; the second switching circuit switch is used for enabling the wireless transceiver chip to be connected with a corresponding common voltage circuit in a conducting mode according to the received second signal;

alternatively, the reference voltage switching circuit module further includes: the second switching circuit switch is used for closing the reference voltage regulating circuit and starting the common voltage circuit; one input end of the second switching circuit switch is electrically connected with the second signal output end of the microprocessor, one input end of the second switching circuit switch is electrically connected with the normal pressure protection circuit, and the output end of the second switching circuit switch is electrically connected with the wireless transceiver chip; and an input end of the second switching power is used for controlling the circuit conduction between the wireless transceiver chip and the normal pressure protection circuit according to the received second signal.

Further preferably, the voltage input end of the wireless transceiver chip is electrically connected between the reference voltage adjusting circuit module and the normal pressure protection circuit, so as to obtain the reference voltage or the common voltage.

Further preferably, the reference voltage adjusting circuit includes: one end of the first regulating resistor is electrically connected with the first output end of the first switching circuit switch, the other end of the first regulating resistor is electrically connected with the wireless transceiver chip, and the second regulating resistor is electrically connected with the second output end of the first switching circuit switch, and the other end of the second regulating resistor is electrically connected with the wireless transceiver chip.

Further preferably, the method further comprises: the storage chip is electrically connected with the microprocessor and is used for storing an identification number matched with the data interaction between the sensor and the trigger; and the microprocessor is used for controlling the reference voltage switching circuit module to start after judging that the trigger is matched with the identification number, and adjusting the carrier frequency so that the trigger generates stable voltage for triggering the data interaction under the influence of the electromagnetic field of the antenna when different preset distances are provided.

Further preferably, the method further comprises: and an output control circuit electrically connected with the microprocessor and used for driving an external load, and a power supply electrically connected with the output control circuit and the microprocessor, wherein the output control circuit comprises: the first protection resistor, the first triode and the first grounding resistor are sequentially and electrically connected with an external load, and the second protection resistor is connected in parallel with a serial circuit formed by the first protection resistor and the first triode; the collector of the first triode is connected with the signal output end of the microprocessor, the base is connected with the first protection resistor, and the emitter is connected with the grounding resistor.

Further preferably, the output control circuit further includes: a detection circuit connected in parallel with the ground resistance; wherein the detection circuit includes: the third protection resistor and the second capacitor are connected in series, the second triode is connected with the second capacitor in parallel, and the collector electrode of the second triode is electrically connected with the microprocessor; the collector of the second triode is grounded through a second grounding resistor, the base is connected with the third protection resistor, and the emitter is connected with the second capacitor.

The application also provides a safety door switch, comprising: a sensor according to any one of the preceding claims.

The application also provides a control method of the safety door switch, which is executed by the sensor according to any one of the above, and comprises the following steps:

acquiring an identification code of the trigger;

judging whether the identification code is matched with a preset identification number or not;

if the matching is successful, the reference voltage switching circuit module is controlled to start, and the reference voltage for supplying power to the wireless transceiver chip is adjusted to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, so that the distance range for carrying out data interaction with the trigger is adjusted in a self-adaptive mode.

Further preferably, the step of controlling the reference voltage switching circuit module to start and adjusting the reference voltage for supplying power to the wireless transceiver chip to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna if the matching is successful includes the steps of:

judging whether the induced voltage is larger than a first preset value or not;

if yes, the reference voltage switching circuit module is controlled to start and switch a reference voltage regulating circuit so as to increase the reference voltage, thereby increasing the modulation depth;

if not, judging whether the induced voltage is smaller than a second preset value;

if yes, the reference voltage switching circuit module is controlled to start and switch the reference voltage regulating circuit so as to reduce the reference voltage, thereby reducing the modulation depth.

Compared with the prior art, the sensor, the safety door switch and the control method thereof can be stably identified by the sensor and perform data interaction when the trigger is close to the sensor.

Drawings

FIG. 1 is a block diagram of a circuit module of a sensor according to an embodiment of the invention;

FIG. 2 is a schematic circuit diagram of a reference voltage switching circuit module according to an embodiment of the invention;

FIG. 3 is a schematic circuit diagram of an output control circuit according to an embodiment of the invention;

FIG. 4 is a control flow chart of a control method of a safety door switch according to an embodiment of the invention;

FIG. 5 is a flowchart showing the step S30 according to an embodiment of the present invention;

FIG. 6 is a control flow chart of a control method of a safety door switch according to a preferred embodiment of the invention;

fig. 7 is a flowchart of S1 in the second embodiment of the invention.

Detailed Description

The sensor of the present invention will be described in more detail below in conjunction with the schematic drawings, wherein preferred embodiments of the present invention are shown, it being understood that one skilled in the art may modify the invention described herein while still achieving the beneficial effects of the present invention. Accordingly, the following description is to be construed as broadly known to those skilled in the art and not as limiting the invention.

Example 1

The present embodiment provides a sensor, as shown in fig. 1 to 4, which is mainly composed of an antenna for receiving radio frequency signals and transmitting carrier signals, a wireless transceiver chip, a reference voltage switching circuit module, an LC resonance circuit (not shown in the drawings) electrically connected to the wireless transceiver chip, a microprocessor, and the like.

The microprocessor is electrically connected with the antenna, the wireless transceiver chip and the reference voltage switching circuit module. The wireless transceiver chip is preferably an RFID chip. The sensor is preferably an RFID sensor.

And the microprocessor is used for controlling the starting of the reference voltage switching circuit module after the trigger is identified by induction, and adjusting the reference voltage for supplying power to the wireless transceiver chip so as to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, thereby adaptively adjusting the distance range for data interaction with the trigger.

From the above, it can be seen that: according to the embodiment, after the trigger is identified by induction, the reference voltage switching circuit module is controlled to be started, and the reference voltage for supplying power to the wireless transceiver chip is adjusted, so that the LC resonant circuit and the antenna voltage can be adjusted, the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna can be adjusted, the antenna and the trigger can generate changes of an electromagnetic field for data interaction, different magnetic fields are generated, the coil of the trigger can obtain stable voltage when the trigger reaches a range matched with the magnetic field, stable data exchange at different distance points can be continuously realized, for example, the carrier frequency is adjusted to 125KHZ, electromagnetic induction can be directly generated with the coil of an electronic tag in the trigger, and further data exchange can be stably performed, that is, when the trigger is close to the sensor, the modulation depth is increased, so that near point triggering is realized, and when the trigger is far away from the sensor, the modulation depth is reduced, the distance range for data interaction with the trigger is adaptively adjusted, the stability of an output signal of the sensor is further improved, the threshold distance of the trigger is effectively avoided, and the trigger is closed to the sensor is frequently started, and the threshold distance of the trigger is used as a driving switch.

In addition, the sensor in the embodiment can be applied to load equipment such as a safety door switch or used as a sensor switch, and through the structure, the frequent start and stop of the load equipment by the sensor when the trigger is close to the critical distance of the sensor can be effectively avoided.

The specific working principle is as follows:

when the trigger is close to the working area of the sensor and is activated by the radio frequency signal emitted by the antenna, the antenna sends the carrier signal with the identification code signal, so that after the wireless transceiver chip converts the received carrier signal into a corresponding induced voltage signal, the trigger is identified, and then the reference voltage switching circuit module can be started to provide corresponding power supply voltage, namely reference voltage, for the wireless transceiver chip, the corresponding reference voltage is adjusted, and then the adjustment of the LC resonant circuit and the antenna voltage matched with the wireless transceiver chip is realized.

Specifically, the reference voltage switching circuit module includes: a first switching circuit switch for regulating the reference voltage. The first switch circuit is electrically connected to the first signal output end of the microprocessor, such as the first signal input end IN1 shown IN fig. 1, and the other end is electrically connected to the wireless transceiver chip and is connected to the voltage signal path between the common voltage circuit and the normal voltage protection circuit. The first switch circuit is configured to switch Guan Fasong the first signal to the first switch circuit after the microprocessor detects the induced voltage signal, that is, the voltage signal corresponding to the carrier signal received by the detected antenna is greater than the corresponding preset value, so that the first switch circuit switch is connected to the corresponding reference voltage adjusting circuit in a conducting manner according to the received first signal. Under the condition that the reference voltage regulating circuit is started, the microprocessor is connected with the corresponding reference voltage regulating circuit in a conducting mode through starting the first switching circuit switch, so that R20 and R21 are selected as different reference resistors, different reference voltages Vmod u are obtained, the different reference voltages Vmod u are provided for the wireless transceiver chip, and therefore an LC resonant circuit matched with the wireless transceiver chip can be influenced by the reference voltages to generate different magnetic fields.

Further preferably, the first switching circuit switch further includes: one end is electrically connected with a second signal output end of the microprocessor, such as a second signal input end IN2 shown IN fig. 1, and the other end is electrically connected with a wireless transceiver chip and is connected with a voltage signal path between the reference voltage regulating circuit module and the normal pressure protection circuit. Through which the reference voltage regulating circuit can be controlled to be turned on and off. When the microprocessor receives the induced voltage, that is, the voltage signal corresponding to the detected carrier signal received by the antenna is smaller than the corresponding preset value, a second signal is sent to the second signal input end IN2 of the first switching circuit switch arranged IN the reference voltage switching circuit module, so that a circuit between the reference voltage regulating circuit and the normal pressure protection circuit is conducted, for example, the circuit is electrically connected with the digital logic voltage DVDD shown IN fig. 2, and the reference regulating voltage circuit IN the reference voltage switching circuit module is closed. The resistance value of the resistor R11 corresponding to the normal pressure protection circuit is preferably 100kΩ. And, the normal pressure protection circuit further includes: a protection capacitor C13 connected in parallel with the resistor R11, wherein C13 is preferably 220N. The VCC terminal of the first switching circuit switch is electrically connected to the digital logic voltage DVDD, and simultaneously, the VCC terminal and the GND terminal of the first switching circuit switch are connected in parallel to the protection capacitor C19, and the capacitance value of the protection capacitor C19 is 100N. In addition, the second signal in this embodiment is preferably a high-level signal, when the second signal output end of the microprocessor sends the high-level signal to the second output end (NC end), the switching circuit switch turns on the circuit loop between the common voltage circuit and the normal-pressure protection circuit, and when the second signal output end of the microprocessor sends the low-level signal to the second output end (NC end), the switching circuit switch turns off the circuit loop between the common voltage circuit and the normal-pressure protection circuit.

In addition, it should be noted that the output voltages of the common voltage circuit and the normal voltage protection circuit are preferably common voltages, and are preferably digital logic voltages DVDD with a voltage level of 3.3V.

Here, it should be noted that the first switching circuit switch in the present embodiment is preferably an analog switch, and the model thereof may preferably be sgm3001.

It should be noted that, as an alternative, the reference voltage switching circuit module in this embodiment may also include: and a second switching circuit switch for controlling the start of the reference voltage switching circuit. Wherein, an input end of the second switching circuit switch is electrically connected with a second signal output end of the microprocessor, an input end of the second switching circuit switch is electrically connected with the reference voltage regulating circuit, and an output end of the second switching circuit switch is electrically connected with the normal pressure protection circuit; and an input end of the second switching power is used for controlling the circuit conduction between the reference voltage regulating circuit and the normal pressure protection circuit according to the received second signal, so as to close the reference voltage switching circuit. Wherein the second switching circuit switch is preferably an analog switch.

Further preferably, a voltage input terminal of the wireless transceiver chip is electrically connected between the reference voltage adjusting circuit and the normal pressure protection circuit for obtaining a reference voltage or a common voltage, and the common voltage circuit is the same as the output voltage of the normal pressure protection circuit

Further preferably, the reference voltage adjusting circuit includes at least: a first regulating resistor R21 having one end electrically connected to a first output terminal of the first switching circuit switch, i.e., the NO terminal as shown in fig. 2, and the other end electrically connected to the wireless transceiver chip, and a second regulating resistor R20 having the other end electrically connected to a second output terminal of the first switching circuit switch, i.e., the NC terminal as shown in fig. 2. The resistance value of the first adjusting resistor R21 is larger than the resistance value of the second adjusting resistor R20, and the resistance value of the first adjusting resistor R21 is 19kΩ. The resistance value of the second regulating resistor R20 is 68kΩ. The microprocessor receives the induced voltage signals with different magnitudes, and outputs voltage signals with different magnitudes, such as a high-level signal and a low-level signal, through a first signal output end of the microprocessor, so as to respectively realize the conduction of a first output end (NO end) and a second output end (NC end), so that the reference voltage regulating circuit provides different reference voltages, and further different modulation depths are realized, for example, when the trigger is relatively close to the sensor, the high-level signal is output through the second signal output end to conduct the NO end, so that the reference voltage is increased, the modulation depth is increased, the trigger distance is relatively greater than that in a normal pressure state, the short-distance trigger is realized, and when the trigger is relatively far away from the sensor, the modulation depth is reduced, the trigger distance is relatively greater than that in a normal pressure state, and the long-distance disconnection is realized. Furthermore, it should be noted that the induced voltage signal corresponding to the high level signal in the present embodiment is greater than the induced voltage signal corresponding to the low level signal.

In addition, it should be noted that the reference voltage adjusting circuit in the embodiment may not be limited to the two paths of adjusting circuits for outputting different reference voltages, and may also realize the output of the reference voltages with different voltage magnitudes by setting a plurality of adjusting resistors with different magnitudes.

Further preferably, the sensor further comprises: the storage chip is electrically connected with the microprocessor and is used for storing an identification number matched with the data interaction between the sensor and the trigger; the microprocessor is used for controlling the reference voltage switching circuit module to start after judging that the trigger is matched with the identification number, and adjusting the carrier frequency, so that the trigger generates stable voltage for triggering data interaction under the influence of the electromagnetic field of the antenna when different preset distances are provided. It should be noted that the trigger in this embodiment mainly comprises an electronic tag chip and a matched coil. After the trigger enters an electromagnetic field provided by the sensor, a matching coil of the trigger can obtain voltage through electromagnetic induction, when the voltage amplitude reaches the minimum voltage required by the starting of the electronic tag, the electronic tag can perform data interaction with the wireless transceiver chip, and the identification number stored by the storage chip can be preferably an electronic tag ID identification number.

Further preferably, in order to facilitate driving of the sensor to an external load, such as a safety door switch, the sensor further comprises: and an output control circuit electrically connected with the microprocessor and used for driving an external load, and a power supply electrically connected with the output control circuit and the microprocessor, wherein the output control circuit comprises: the first protection resistor R14, the first triode T1 and the first grounding resistor R16 are sequentially and electrically connected with an external load, and the second protection resistor R17 is connected in parallel with a serial circuit formed by the first protection resistor R14 and the first triode T1; the collector of the first triode T1 is connected with the signal output end out1 of the microprocessor, the base is connected with the first protection resistor R14, and the emitter is connected with the grounding resistor R16. The ground resistor R16 is connected to the ground GND, and has a resistance of 2.2Ω. The resistance of the first protection resistor R14 is preferably 1kΩ. The resistance of the second protection resistor R17 is preferably 10kΩ.

Further preferably, in order to enable the sensor to output a load start signal or a load stop signal to an external load through the output control circuit, the output control circuit further includes: a detection circuit connected in parallel with the ground resistor R16; wherein the detection circuit includes: the third protection resistor R15 and the second capacitor C14 are connected in series, the second triode T2 is connected with the second capacitor C14 in parallel, and the collector electrode of the second triode T2 is electrically connected with the microprocessor; the collector of the second triode T2 is grounded through a second grounding resistor R13, the base is connected with a third protection resistor R15, and the emitter is connected with a second capacitor C1. The resistance of the third protection resistor R15 is preferably 1kΩ. The resistance of the second ground resistor R13 is preferably 10kΩ. The capacitance value of the second capacitor C14 is 2.2N.

When the first protection resistor R14, the first transistor T1, the first ground resistor R16, and the second protection resistor R17 connected in parallel with the series circuit formed by the first protection resistor R14 and the first transistor T1, etc. are connected to an external load, for example, the output terminal out for electrically connecting the load shown in fig. 4, in order, a power supply is connected to form a load loop, if the current of the load loop is too large, the emitter of the second transistor T2 generates a falling edge level, so that the microprocessor receives the falling edge level through the base of the second transistor T2, thereby controlling the signal output terminal thereof, stopping delivering the output signal, and thus stopping driving the load.

In addition, the sensor further includes: the power supply conversion module is electrically connected with the microprocessor and an external power supply to realize voltage stabilization power supply to the microprocessor, the wireless transceiver chip, the output control circuit, the reference voltage regulating circuit, the LC resonance circuit and the antenna in the sensor.

In addition, it should be noted that the digital logic voltage DVDD in the output control circuit is preferably 3.3V.

Example two

The embodiment also provides a safety door switch, comprising: the sensor of any of the above embodiments.

Example III

The present embodiment also provides a control method of a safety door switch, which is executed by the sensor in the second embodiment, as shown in fig. 3, and includes the following steps:

step S10: acquiring an identification code of a trigger;

step S20: judging whether the identification code is matched with a preset identification number or not;

step S30: if the matching is successful, the reference voltage switching circuit module is controlled to start, and the reference voltage for supplying power to the wireless transceiver chip is adjusted to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, so that the distance range for data interaction with the trigger is adjusted in a self-adaptive mode.

Through the steps, after the trigger is identified by induction, the microprocessor can control the reference voltage switching circuit module to start in an identity pairing identification mode, and adjust the reference voltage mode for supplying power to the wireless transceiver chip, the LC resonant circuit and the antenna voltage can be adjusted, so that the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna can be adjusted, the antenna and the trigger carry out data interaction electromagnetic field to generate different magnetic fields, the trigger can acquire stable voltage at different distance points continuously when reaching the range matched with the magnetic field, for example, the carrier frequency is adjusted to 125KHZ, electromagnetic induction can be directly generated with the coil of the electronic tag in the trigger, and then the data exchange can be carried out stably, that is, when the trigger is close to the sensor, the modulation depth is increased, so that near point triggering is realized, when the trigger is far away from the sensor, the modulation depth is reduced, the distance range of data interaction between the antenna and the trigger is self-adaptively adjusted, the stability of the sensor output signal is further improved, when the trigger reaches the range matched with the magnetic field, the trigger is close to the sensor, the threshold is prevented from being used as a threshold, the threshold switch is prevented from being closed, and the threshold is prevented from being frequently opened, and the threshold is especially used for the threshold switch.

Further preferably, when the matching is successful, the step of controlling the reference voltage switching circuit module to start and adjusting the reference voltage for supplying power to the wireless transceiver chip to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, as shown in fig. 4, i.e. step S30 includes the steps of:

step S301: judging whether the induced voltage is larger than a first preset value or not;

step S302: if yes, the reference voltage switching circuit module is controlled to start and switch the reference voltage regulating circuit so as to increase the reference voltage, thereby increasing the modulation depth and reacquiring the induced voltage. Specifically, when the micro-processing of the sensor receives the induced voltage and determines that the induced voltage is greater than a corresponding first preset value, a high-level first signal is sent to the circuit switching switch, so that a corresponding reference voltage regulating circuit is conducted and connected according to the received high-level first signal, the reference voltage is increased while the starting of the reference voltage regulating circuit is realized, the modulation depth is increased, and therefore, compared with the triggering distance in a normal pressure state, the short-distance triggering is realized.

Step S303: if not, judging whether the induced voltage is larger than a second preset value, wherein the second preset value is smaller than the first preset value;

step S304: if yes, the reference voltage switching circuit module is controlled to start and switch the reference voltage regulating circuit so as to reduce the reference voltage, thereby reducing the modulation depth and reacquiring the induced voltage; specifically, when the micro-processing of the sensor receives the induced voltage and judges that the induced voltage is smaller than a first preset value but larger than a second preset value, a low-level first signal is sent to the circuit switching switch, so that the corresponding reference voltage regulating circuit is connected in a conducting manner according to the received first signal, the corresponding reference voltage regulating circuit is connected in a conducting manner according to the received high-level first signal, the reference voltage is reduced while the opening of the reference voltage regulating circuit is realized, the modulation depth is reduced, and further, the far-point trigger with a longer distance is realized compared with the trigger distance in a normal pressure state.

Step S305: if not, closing the reference voltage switching circuit module. Specifically, when the micro-processing of the sensor receives the induced voltage and determines that the induced voltage is smaller than a corresponding second preset value, a second signal is sent to the circuit switching switch, so that the corresponding common voltage circuit and the normal pressure protection circuit are connected in a conducting mode according to the received second signal, and the reference voltage switching circuit module is closed. Here, it is explained that the off reference voltage switching circuit module in the present embodiment also refers to a state in which the reference voltage switching circuit module is switched to the normal voltage circuit by the reference voltage adjusting circuit.

By the method, different modulation depths can be obtained, the distance range for data interaction with the trigger can be adjusted in a self-adaptive mode, stability of output signals of the sensor is further improved, and the sensor is effectively prevented from being frequently started and stopped as a driving switch when the trigger is close to the critical distance of the sensor.

Here, the first preset value in the present embodiment is preferably 0.8V, and the second preset value is preferably 1.5V, which is only taken as an example and not particularly limited.

In addition, as a preferred embodiment, the step of acquiring the identification code of the trigger, as shown in fig. 5, that is, before step S10, includes the steps of:

step S1: acquiring an induced voltage signal matched with the trigger;

step S2: according to the induced voltage signal, sending a query command to the trigger, wherein after receiving the query command, the trigger generates a random code according to a preset algorithm and sends the random code to the sensor; wherein, the preset algorithm may be preferably a random generation algorithm. Wherein the random code may preferably be a random number, e.g. a natural number greater than 0.

Step S3: generating an encryption code according to the received random code and a preset rule; wherein the preset rule may preferably be a random generation algorithm. Wherein the preset rule may be preferably a random generation algorithm, and the encryption code may be preferably a random number, for example, a natural number greater than 0.

Step S4: calculating to obtain a key number according to the random code, the encryption code and a preset key algorithm;

step S5: and sending the key number to the trigger, wherein the trigger decodes the key number according to a preset decryption algorithm and the random code to obtain a decryption code, binds the decryption code with the identification code and then sends the binding code to the sensor.

Step S6: judging whether the obtained decryption code is matched with the encryption code or not;

step S7: if the matching is successful, unbinding and acquiring the identification code, otherwise, acquiring the induced voltage signal again until the matching is failed for a plurality of times, and exiting.

Through the steps, before the sensor and the trigger are matched and identified, when the trigger approaches the sensor body, the mutual authentication is performed after the voltage signal generated on the sensor due to the impedance effect, so that the technical problem that the identification code is matched too early due to large fluctuation when a user frequently approaches or gets far away from the sensor when using the trigger is avoided, and the trigger and the sensor respectively generate the corresponding random code and the corresponding encryption code to encrypt and decrypt, so that the trigger and the sensor can be ensured to be matched and authenticated only due to electromagnetic induction under the condition of no identification code, and the trigger cannot trigger the corresponding operation instruction due to the fact that the sensor is started too early due to the fact that the trigger is mistakenly approaching the sensor is avoided. In addition, encryption can be kept in the matching process through a key algorithm and a decryption algorithm, so that potential safety hazards caused by information leakage can be well avoided.

In addition, it should be noted that the key algorithm and the decryption algorithm in this embodiment may preferably be the same set of algorithms and are mutually inverse operations, such as DESL, AES, HIGHT, XXTEA algorithm, and the like.

Furthermore, by the steps, the condition that the trigger is matched with other adjacently arranged sensors can be avoided.

As shown in fig. 7, the step of acquiring the induced voltage signal matched with the trigger, that is, step S1 includes the following steps:

step S11: when the plurality of the obtained induced voltage signals are in a set time and rule, calculating an average voltage value of the induced voltage corresponding to each induced voltage signal, specifically, the set time and rule may be: setting the period of the induced voltage signal to be 50ms, and detecting at least five periods of the induced voltage signal;

step S12: judging whether the average voltage value is larger than a preset average voltage value or not;

step S13: if yes, taking the average voltage value as the induction voltage;

step S14: if not, continuing to judge until exiting after the preset time, wherein the preset time can be preferably 2 s.

By means of the method of obtaining the average value through the induction voltage signals obtained multiple times, interference caused by unstable generated voltage signals can be reduced.

The foregoing is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art will make any equivalent substitution or modification to the technical solution and technical content disclosed in the invention without departing from the scope of the technical solution of the invention, and the technical solution of the invention is not departing from the scope of the invention.

Claims (12)

1. A sensor, comprising:

an antenna;

a wireless transceiver chip;

a reference voltage switching circuit module electrically connected with the wireless transceiver chip;

an LC resonant circuit electrically connected to the wireless transceiver chip;

a microprocessor electrically connected to the antenna, the wireless transceiver chip, and the reference voltage switching circuit module;

the microprocessor is used for controlling the reference voltage switching circuit module to start after sensing and identifying an external trigger, and adjusting the reference voltage for supplying power to the wireless transceiver chip so as to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, thereby adaptively adjusting the distance range for carrying out data interaction with the trigger.

2. The sensor of claim 1, wherein the reference voltage switching circuit module is configured to output more than two reference voltages, wherein the reference voltages comprise at least: a first reference voltage greater than the common voltage, at least one second reference voltage less than the common voltage; the common voltage is the voltage for supplying power to the wireless transceiver chip when the reference voltage switching circuit module is switched to the common voltage circuit or the reference voltage switching circuit module is closed by the reference voltage regulating circuit.

3. The sensor of claim 1 or 2, wherein the reference voltage switching circuit module comprises: a first switching circuit switch for regulating the reference voltage; the first switching circuit switch is electrically connected with the first signal output end of the microprocessor, and the other end of the first switching circuit switch is electrically connected with the wireless transceiver chip; the first switching circuit switch is used for enabling the wireless transceiver chip to be connected with the corresponding reference voltage regulating circuit in a conducting mode according to the received first signal.

4. The sensor of claim 3, wherein the first switching circuit switch further comprises: one end of the wireless transceiver chip is electrically connected with the second signal output end of the microprocessor, and the other end of the wireless transceiver chip is electrically connected with the second signal output end of the microprocessor; the second switching circuit switch is used for enabling the wireless transceiver chip to be connected with a corresponding common voltage circuit in a conducting mode according to the received second signal;

alternatively, the reference voltage switching circuit module further includes: the second switching circuit switch is used for closing the reference voltage regulating circuit and starting the common voltage circuit; one input end of the second switching circuit switch is electrically connected with the second signal output end of the microprocessor, one input end of the second switching circuit switch is electrically connected with the normal pressure protection circuit, and the output end of the second switching circuit switch is electrically connected with the wireless transceiver chip; and an input end of the second switching power is used for controlling the circuit conduction between the wireless transceiver chip and the normal pressure protection circuit according to the received second signal.

5. The sensor of claim 4, wherein a voltage input of the wireless transceiver chip is electrically connected between the reference voltage regulation circuit module and the normal voltage protection circuit.

6. The sensor of claim 3, wherein the reference voltage adjustment circuit module comprises: one end of the first regulating resistor is electrically connected with the first output end of the first switching circuit switch, the other end of the first regulating resistor is electrically connected with the wireless transceiver chip, and the second regulating resistor is electrically connected with the second output end of the first switching circuit switch, and the other end of the second regulating resistor is electrically connected with the wireless transceiver chip.

7. The sensor as recited in claim 1, further comprising: the storage chip is electrically connected with the microprocessor and is used for storing an identification number matched with the data interaction between the sensor and the trigger; and the microprocessor is used for controlling the reference voltage switching circuit module to start after judging that the trigger is matched with the identification number, and adjusting the carrier frequency so that the trigger generates stable voltage for triggering the data interaction under the influence of the electromagnetic field of the antenna when different preset distances are provided.

8. The sensor as recited in claim 1, further comprising: and an output control circuit electrically connected with the microprocessor and used for driving an external load, and a power supply electrically connected with the output control circuit and the microprocessor, wherein the output control circuit comprises: the first protection resistor, the first triode and the first grounding resistor are sequentially and electrically connected with an external load, and the second protection resistor is connected in parallel with a serial circuit formed by the first protection resistor and the first triode; the collector of the first triode is connected with the signal output end of the microprocessor, the base is connected with the first protection resistor, and the emitter is connected with the grounding resistor.

9. The sensor of claim 8, wherein the output control circuit further comprises: a detection circuit connected in parallel with the ground resistance; wherein the detection circuit includes: the third protection resistor and the second capacitor are connected in series, the second triode is connected with the second capacitor in parallel, and the collector electrode of the second triode is electrically connected with the microprocessor; the collector of the second triode is grounded through a second grounding resistor, the base is connected with the third protection resistor, and the emitter is connected with the second capacitor.

10. A safety door switch, comprising: the sensor of any one of the preceding claims 1 to 9.

11. A control method of a safety door switch, characterized in that it is performed by a sensor according to any one of the preceding claims 1 to 10, comprising the steps of:

acquiring an identification code of the trigger;

judging whether the identification code is matched with a preset identification number or not;

if the matching is successful, the reference voltage switching circuit module is controlled to start, and the reference voltage for supplying power to the wireless transceiver chip is adjusted to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna, so that the distance range for carrying out data interaction with the trigger is adjusted in a self-adaptive mode.

12. The method according to claim 11, wherein the step of controlling the reference voltage switching circuit module to be started and adjusting the reference voltage for supplying power to the wireless transceiver chip to adjust the resonant frequency of the LC resonant circuit and the carrier frequency of the antenna if the matching is successful comprises the steps of:

judging whether the induced voltage is larger than a first preset value or not;

if yes, the reference voltage switching circuit module is controlled to start and switch a reference voltage regulating circuit so as to increase the reference voltage, thereby increasing the modulation depth;

if not, judging whether the induced voltage is smaller than a second preset value;

if yes, the reference voltage switching circuit module is controlled to start and switch the reference voltage regulating circuit so as to reduce the reference voltage, thereby reducing the modulation depth.