CN116817975A - Self-driven wireless double-parameter sensing system based on friction electrification and double-resonance circuit - Google Patents

Abstract

The application discloses a self-driven wireless double-parameter sensing system based on friction electrification and a double-resonance circuit. The self-driven wireless double-parameter sensing system comprises a self-powered module, a symmetrical double-resonant circuit and a wireless signal transmission module. The self-energy supply module comprises a friction nano generator and an electronic switch; the wireless signal transmission module receives the frequency signals of the two capacitive sensors in the symmetrical double-resonance circuit in a wireless transmission mode through the signal output coil. The application combines the friction nano generator, can collect the mechanical energy of the surrounding environment and convert the mechanical energy into electric energy under the condition of no external active management circuit and battery, provides energy for the electronic switch and the resonance sensing circuit, solves the long-term power supply problem of the sensor, and reduces the monitoring cost of factories. In addition, the application can form a wireless transmission system by utilizing the electronic element of the symmetrical double-resonance circuit and matching with an external receiving inductance or receiving antenna, and can monitor the condition of the two sensors under the change of external environment in real time.

Description

Self-driven wireless double-parameter sensing system based on friction electrification and double-resonance circuit

Technical Field

The application belongs to the technical field of multi-parameter measurement, and particularly relates to a self-driven wireless double-parameter sensing system based on friction electrification and a double-resonance circuit.

Background

The friction nano generator is used as a novel nano energy source, and the amplitude of output voltage or current of the friction nano generator can be obviously changed under the influence of environmental parameters, such as temperature, humidity, air pressure or pressure. The friction nano-generator can convert the environmental mechanical vibration around the sensor into electric energy, such as raindrop, object movement, etc., and thus can be used to solve the energy supply problem in the sensor network. The TENG self-driven sensor can replace the traditional sensor to measure the physical quantities such as eddy current, pressure, humidity, temperature, displacement and the like. The TENG self-driven sensor has the defects that the parameters which can be sensed are limited, the TENG self-driven sensor cannot be applied to the sensing fields such as gas, magnetic fields, micro strain pressure and the like, and the application range cannot be limited in the application range compared with the existing sensors with various types.

The friction nano generator (TriboelectricNanogenerator, TENG) is a novel energy collecting device and can realize the function of converting mechanical energy around a sensor system into electric energy. The friction nano generator has the advantages of small volume, low cost, better output performance and the like, and is very suitable for being used as an energy supply module in a self-energy-supply wearing system. The self-powered wearable system means that the whole system can realize closed-loop energy collection and utilization, mechanical energy around the sensing system is converted to obtain electric energy, the sensor is powered after simple treatment, and the problem of power supply of the sensor is solved from the source. The advent of friction nano generators provides a new concept for the sensor energy supply problem, and the resolution of further sensor development.

Currently, because sensor nodes have no information storage capability and are typically distributed in factories or inaccessible locations, there is a need to be able to wirelessly transmit sensed information to a remote control center in real time. The pulse voltage output generated by TENG can be converted into a damping oscillation signal with coded sensing information through the sensing circuit system so as to facilitate wireless transmission. The wireless sensing system directly adopts TENG as a power supply, so that a series of energy conversion processes are avoided, and the sensing system has high energy utilization efficiency.

The wireless sensing system based on TENG in the prior art mostly uses a single resonator to generate a transmission signal, wherein single parameter sensing uses sensing information of one of a resistive sensor, a capacitive sensor and an inductive sensor for wireless transmission, and the information of single parameter sensing only includes one of pressure, humidity, temperature, displacement, vortex and the like, so that the available sensing parameters are relatively limited. A wireless double-parameter sensing system capable of monitoring two environmental parameters simultaneously can further improve the application prospect of the sensor system.

Disclosure of Invention

Aiming at the defects of the prior art, the application provides a wireless double-parameter sensing system based on a friction nano generator, wherein the friction nano generator is used as an energy source, two capacitive sensors are selected in a symmetrical double-resonance circuit, two resonance frequencies of the circuit are mutually noninterfered by utilizing unique electrical characteristics and are respectively changed along with the change of one sensitive capacitor, the problem of multi-parameter sensing is solved, and wireless transmission is realized by utilizing a litz coil and an antenna.

The self-driven wireless double-parameter sensing system based on the friction electrification and double-resonance circuit comprises a self-power supply module, a symmetrical double-resonance circuit and a wireless signal receiving module. The self-powered module comprises a friction nano generator and an electronic switch; the output interface of the self-powered module is connected with the symmetrical double-resonant circuit. In the working process, the electronic switch is used for realizing instant discharge, so that the self-power supply module provides pulse signals for the symmetrical double-resonance circuit.

The symmetrical double-resonance circuit comprises an inductance coil L1, an inductance coil L2, a capacitance type sensor Cx, a capacitance type sensor Cy, a capacitance C1 and a capacitance C2. Either one of the inductance coil L1 and the inductance coil L2 serves as a signal output coil; the wireless signal receiving module receives the frequency signals of the capacitive sensor Cx and the capacitive sensor Cy by wireless transmission through the signal output coil.

Preferably, one end of the capacitive sensor Cx is connected to one end of the inductor L1 or the inductor L2; the other end of the capacitance sensor Cx is connected to one of the capacitances C1 and C2. The other ends of the inductance coil L1 and the capacitance C1 are connected to one end of the capacitance sensor Cy. The other ends of the inductance coil L2 and the capacitor C2 are connected to the other end of the capacitive sensor Cy, and grounded.

Preferably, the output interface of the self-powered module is connected in parallel to two ends of the inductance coil L2 of the symmetrical dual-resonance circuit.

Preferably, either one or both of the capacitor C1 and the capacitor C2 are used as an omnidirectional wireless transmitting module; the capacitor C1 or the capacitor C2 serving as the omnidirectional wireless transmitting module adopts a double open-circuit antenna structure; the dual open antenna structure includes two helical conductors. The two spiral wires are nested together and are not conducted.

Preferably, the spiral wire is an enameled wire.

Preferably, the wireless signal receiving module adopts a receiving coil L3. The receiving coil L3 and the signal output coil can perform signal wireless transmission by means of inductive coupling.

Preferably, the distance between the receiving coil L3 and the signal output coil is smaller than or equal to 5cm.

Preferably, the wireless signal receiving module transmits the received signal to the signal reading module, and performs fourier transform to obtain frequencies of the capacitive sensor Cx and the capacitive sensor Cy.

Preferably, the signal reading module adopts an oscilloscope.

Preferably, the inductor L1 and the inductor L2 are litz coils.

The working method of the self-driven wireless double-parameter sensing system comprises the following steps:

step 1, disposing a friction nano generator, an electronic switch and a symmetrical double-resonance circuit; and reading the signal output by the wireless signal receiving module, and carrying out Fourier transform on the signal to obtain a system frequency f1 and a system frequency f2. First, the capacitance value of the capacitive sensor Cx is changed, and a corresponding system frequency f2 is recorded, thereby obtaining a table of the relationship between the system frequency f2 and the capacitance value of the capacitive sensor Cx. Then, the capacitance value of the capacitive sensor Cy is changed, the corresponding system frequency f1 is recorded, and a relation table of the system frequency f1 and the capacitance value of the capacitive sensor Cy is obtained.

Step 2, arranging the capacitive sensor Cx and the capacitive sensor Cy in the measured environment respectively for data acquisition; reading the frequencies corresponding to the capacitive sensors Cx and Cy respectively; respectively calculating capacitance values of the capacitive sensor Cx and the capacitive sensor Cy through the two relation tables obtained in the step 1; and the sizes of the two measured data are calculated according to the capacitance values of the capacitive sensor Cx and the capacitive sensor Cy.

The application has the following beneficial effects:

1. the application combines the friction nano generator, can collect the mechanical energy of the surrounding environment and convert the mechanical energy into electric energy under the condition of no external active management circuit and battery, provides energy for the electronic switch and the resonance sensing circuit, solves the long-term power supply problem of the sensor, reduces the monitoring cost of factories, and has potential economic and social benefits.

2. The application makes the two resonance frequencies of the circuit not interfere with each other by utilizing the unique electrical characteristics, and the two resonance frequencies are respectively changed along with the change of one sensitive capacitor, so that the double-parameter sensing is performed, the wide applicability and the high real-time performance of the sensing and transmitting system based on the friction nano generator are improved, and the application can be applied to occasions with high requirements on the real-time performance and the applicability, such as physiological monitoring, engineering environment monitoring, security and theft prevention, battlefield monitoring and the like.

3. The application can form a wireless transmission system by utilizing the electronic element of the symmetrical double-resonance circuit and matching with an external receiving inductance or receiving antenna, and monitors the condition of the two sensors under the change of external environment in real time.

Drawings

Fig. 1 is a schematic circuit diagram of an embodiment 1 of the present application;

FIG. 2 is a schematic diagram showing the operation of embodiment 1 of the present application;

fig. 3 is a schematic circuit diagram of embodiment 2 of the present application;

fig. 4 is a schematic diagram illustrating the frequency consistency of a transmitting signal of a wireless transmitting module and a receiving signal of a wireless receiving module in embodiment 2 of the present application;

FIG. 5 is a graph showing the relationship between frequency and amplitude as a function of humidity in example 3 of the present application;

FIG. 6 is a graph showing the relationship between frequency and amplitude as a function of liquid level in example 3 of the present application;

Detailed Description

The following is a description of various embodiments of the application, which are given by way of example only and by reference to the accompanying drawings.

Example 1

As shown in fig. 1, the self-driven wireless dual-parameter sensing system based on the friction electrification and dual-resonance circuit realizes signal transmission through the inductive coupling principle. The self-driven wireless double-parameter sensing system comprises a self-powered module, a symmetrical double-resonant circuit and a wireless signal receiving module.

The self-energy supply module comprises a friction nano generator and an electronic switch; the electronic switch is used for realizing instant discharge, so that the self-power supply module can output pulse signals.

The symmetrical double resonant circuit includes an inductance coil L1, an inductance coil L2, a capacitance type sensor Cx, a capacitance type sensor Cy, a capacitance C1, and a capacitance C2. One end of the capacitive sensor Cx is connected to one end of the inductor L1 or the inductor L2; the other end of the capacitance sensor Cx is connected to one of the capacitances C1 and C2. The other ends of the inductance coil L1 and the capacitance C1 are connected to one end of the capacitance sensor Cy. The other ends of the inductance coil L2 and the capacitor C2 are connected to the other end of the capacitive sensor Cy, and grounded.

The output interfaces of the self-energy supply module are connected in parallel with two ends of an inductance coil L2 of the symmetrical double-resonance circuit. Both inductor L1 and inductor L2 are able to detect the superimposed signal of the two resonance signals. The two resonance signals are respectively the resonance signals output by the capacitive sensor Cx and the capacitive sensor Cy. Then, two independent resonance signals can be resolved by fourier transformation.

Either one of the inductance coil L1 and the inductance coil L2 serves as a signal output coil; the wireless signal receiving module adopts a receiving coil L3. The receiving coil L3 is close to the signal output coil. The signal output coil can be inductively coupled with the wireless signal receiving module to realize signal transmission.

Both ends of the receiving coil L3 are connected with the signal reading module. In this embodiment, the signal reading module adopts an oscilloscope, and can read and intuitively display the detection signals of the capacitive sensor Cx and the capacitive sensor Cy.

In some embodiments, inductor L1 is specifically used as the signal output coil; the receiving coil L3 and the inductance coil L1 are aligned with each other, and the interval is 5cm.

In some embodiments, inductor L1 and inductor L2 each employ litz coils with high sensitivity and stability.

The frequency range of the capacitive sensor Cx is higher than the frequency range of the capacitive sensor Cy.

As shown in fig. 2, the method for constructing and calibrating the self-driven wireless dual-parameter sensing system comprises the following steps:

step 1, disposing a friction nano generator, an electronic switch and a symmetrical double-resonance circuit; the oscilloscope performs Fourier transform on the output signal to obtain a system frequency f1 with lower frequency and a system frequency f2 with higher frequency. First, the capacitance value of the capacitive sensor Cx is changed, and the fourier transformed system frequency f2 on the oscilloscope is recorded, thereby obtaining a table of the relationship between the system frequency f2 and the capacitance value of the capacitive sensor Cx. Then, the capacitance value of the capacitive sensor Cy is changed, the system frequency f1 after Fourier transformation on the oscilloscope is recorded, and a relation table of the system frequency f1 and the capacitance value of the capacitive sensor Cy is obtained.

Step 2, arranging the capacitive sensor Cx and the capacitive sensor Cy in the measured environment respectively for data acquisition; the oscilloscope reads the frequencies corresponding to the capacitive sensor Cx and the capacitive sensor Cy respectively; respectively calculating capacitance values of the capacitive sensor Cx and the capacitive sensor Cy through the two relation tables obtained in the step 1; and the sizes of the two measured data are calculated according to the capacitance values of the capacitive sensor Cx and the capacitive sensor Cy.

Example 2

The difference between the present embodiment and embodiment 1 is that: the system realizes remote signal transmission through the omnidirectional wireless transmitting module.

Two signal output ends of the wireless receiving module are connected with the signal reading module. In this embodiment, the signal reading module adopts an oscilloscope, and can read and intuitively display the detection signals of the capacitive sensor Cx and the capacitive sensor Cy.

Compared with the embodiment 1, the wireless transmission can be carried out at a longer distance in the embodiment, and the relative positions of the wireless signal receiving module and the symmetrical double-resonance circuit are not required, so that the wireless transmission at a distance of 2m-3m or even longer can be realized. A high-gain amplifier is arranged between the wireless receiving module and the oscilloscope to amplify signals, so that a damping oscillation signal with coded sensing information is displayed on the oscilloscope, and wireless double-parameter transmission is realized.

In this embodiment, any one or both of the capacitor C1 and the capacitor C2 is used as an omni-directional wireless transmitting module, and is used for transmitting signals to the outside wirelessly; in order to realize wireless transmission, a capacitor C1 or a capacitor C2 serving as an omnidirectional wireless transmitting module adopts a double open-circuit antenna structure; specifically, the dual open antenna structure includes two helical conductors with insulated outer surfaces. The two spiral wires are non-conductive and are nested with each other to form a structure similar to a double spiral wire.

The two spiral wires are mutually nested together, have larger relative area, and can be used as a capacitor and an antenna at the same time. The signal sent by the double open-circuit antenna structure contains information of frequencies f1 and f2; therefore, the omni-directional wireless transmission of the self-driven wireless double-parameter sensing system signal is realized.

In this embodiment, the spiral wire is formed by spirally winding an enameled wire.

The wireless receiving module is formed by winding copper wires around an insulating cylinder, and can receive wireless signals transmitted by the omnidirectional wireless transmitting module.

As shown in fig. 4, the transmission signal of the omni-directional wireless transmission module and the reception signal of the wireless reception module in this embodiment can be seen, and the feasibility of short-distance wireless transmission is verified by performing fourier transform to obtain the same system double resonant frequency.

Example 3

The difference between the present embodiment and embodiment 1 is that: the capacitive sensor Cx is in particular a capacitive humidity sensor; the capacitive sensor Cy is in particular a capacitive liquid level sensor.

In this embodiment, dual parameter sensing is achieved by a capacitive humidity sensor and a capacitive liquid level sensor.

The capacitive humidity sensor is arranged in a closed box with a through hole; the two through holes are respectively used for the inlet and the outlet of nitrogen with certain humidity. The change in humidity causes a change in the capacitance value of the capacitive humidity sensitive capacitive sensor, which in turn causes a change in the frequency f2 in the symmetrical double resonant circuit. The capacitive liquid level sensor is arranged in a cup filled with liquid, the liquid height is changed, the scale of the liquid column is recorded, and the change of the liquid height causes the capacitance value of the liquid level capacitive sensor to change, so that the frequency f1 in the symmetrical double-resonance circuit is changed.

Fig. 5 is a schematic diagram showing that the change of the capacitance of the capacitive humidity sensor causes the change of the frequency of the system f2 under the condition that the liquid position is unchanged, and as the humidity is higher, the capacitance Cx of the capacitive humidity sensor is higher, the frequency f2 in the system is smaller, and the frequency f1 is unchanged.

Fig. 6 is a schematic diagram showing that the change of the capacitance of the capacitive liquid level sensor causes the change of the frequency of the system f1 under the condition of unchanged humidity environment, and it can be seen that when the height of the liquid is larger, the capacitance value Cy of the capacitive liquid level sensor is larger, the frequency f1 in the system is smaller, and the frequency f2 is unchanged.

The above description of the embodiments is only for aiding in the understanding of the method of the present application and its core ideas. It should be noted that any number of modifications and improvements to the application without departing from the principles of the application and without paying the inventive faculty fall within the scope of the claims.

Claims (10)

1. The self-driven wireless double-parameter sensing system based on the friction electrification and the double-resonance circuit comprises a symmetrical double-resonance circuit; the method is characterized in that: the system also comprises a self-energy supply module and a wireless signal receiving module; the self-powered module comprises a friction nano generator and an electronic switch; the output interface of the self-powered module is connected with a symmetrical double-resonance circuit; in the working process, the electronic switch controls the self-power supply module to provide pulse signals for the symmetrical double-resonance circuit;

the symmetrical double-resonance circuit comprises an inductance coil L1, an inductance coil L2, a capacitance type sensor Cx, a capacitance type sensor Cy, a capacitance C1 and a capacitance C2; either one of the inductance coil L1 and the inductance coil L2 serves as a signal output coil; the wireless signal receiving module receives the frequency signals of the capacitive sensor Cx and the capacitive sensor Cy by wireless transmission through the signal output coil.

2. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit of claim 1, wherein: one end of the capacitive sensor Cx is connected to one end of the inductor L1 or the inductor L2; the other end of the capacitance sensor Cx is connected with one end of a capacitance C1 and one end of a capacitance C2; the other ends of the inductance coil L1 and the capacitor C1 are connected with one end of the capacitive sensor Cy; the other ends of the inductance coil L2 and the capacitance C2 are connected to the other end of the capacitance sensor Cy.

3. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit of claim 2, wherein: the output interfaces of the self-powered module are connected in parallel with the two ends of the inductance coil L2 of the symmetrical double-resonance circuit.

4. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit of claim 1, wherein: either one or two of the capacitor C1 and the capacitor C2 are used as an omnidirectional wireless transmitting module; the capacitor C1 or the capacitor C2 serving as the omnidirectional wireless transmitting module adopts a double open-circuit antenna structure; the double open-circuit antenna structure comprises two spiral wires; the two spiral wires are nested together and are not conducted.

5. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit of claim 4, wherein: the spiral wire adopts enameled wire.

6. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit of claim 1, wherein: the wireless signal receiving module adopts a receiving coil L3; the receiving coil L3 and the signal output coil can perform signal wireless transmission in an inductive coupling mode; the distance between the receiving coil L3 and the signal output coil is smaller than or equal to 5cm.

7. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit according to any one of claims 1-6, wherein: the wireless signal receiving module transmits the received signals to the signal reading module to perform Fourier transformation to obtain the frequencies of the capacitive sensor Cx and the capacitive sensor Cy.

8. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit of claim 7, wherein: the signal reading module adopts an oscilloscope.

9. The self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuit of claim 1, wherein: and the inductance coil L1 and the inductance coil L2 are all litz coils.

10. The method of operating a self-driven wireless dual-parameter sensing system based on triboelectric charging and dual-resonant circuits of claim 1, wherein: the method comprises the following steps:

step 1, disposing a friction nano generator, an electronic switch and a symmetrical double-resonance circuit; reading a signal output by the wireless signal receiving module, and carrying out Fourier transform on the signal to obtain a system frequency f1 and a system frequency f2; firstly, changing the capacitance value of a capacitive sensor Cx, and recording the corresponding system frequency f2 to obtain a relation table of the system frequency f2 and the capacitance value of the capacitive sensor Cx; then, changing the capacitance value of the capacitive sensor Cy, and recording the corresponding system frequency f1 to obtain a relation table of the system frequency f1 and the capacitance value of the capacitive sensor Cy;

step 2, arranging the capacitive sensor Cx and the capacitive sensor Cy in the measured environment respectively for data acquisition; reading the frequencies corresponding to the capacitive sensors Cx and Cy respectively; respectively calculating capacitance values of the capacitive sensor Cx and the capacitive sensor Cy through the two relation tables obtained in the step 1; and the sizes of the two measured data are calculated according to the capacitance values of the capacitive sensor Cx and the capacitive sensor Cy.