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CN116318438B - Vibration beam-based long-wave communication system and method thereof - Google Patents

Vibration beam-based long-wave communication system and method thereof

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Publication number
CN116318438B
CN116318438B CN202310135199.8A CN202310135199A CN116318438B CN 116318438 B CN116318438 B CN 116318438B CN 202310135199 A CN202310135199 A CN 202310135199A CN 116318438 B CN116318438 B CN 116318438B
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vibration
permanent magnet
signal
electromotive force
induced electromotive
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CN116318438A (en
Inventor
王积硕
袁卫锋
黄楷焱
康健炜
古斌
张苗
李宗阳
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Southwest University of Science and Technology
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Southwest University of Science and Technology
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/0082—Monitoring; Testing using service channels; using auxiliary channels
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
    • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/10—Monitoring; Testing of transmitters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/20—Monitoring; Testing of receivers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/309—Measuring or estimating channel quality parameters
    • H04B17/318—Received signal strength
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Signal Processing (AREA)
  • Quality & Reliability (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

本发明公开了一种基于振动梁的长波通信系统及其方法，所述基于振动梁的长波通信系统包括：信号发生装置，所述信号发生装置用于生成激励信号，并根据所述激励信号进行振动，以带动辐射源装置进行振动；辐射源装置，所述辐射源装置用于生成时变磁场；信号接收装置，所述信号接收装置用于感应所述时变磁场，生成感应电动势，并对所述感应电动势进行数据处理，以实现通信。本发明通过对永磁体机械天线的动力学特性进行分析，实现了利用小尺寸机械天线对低频段信号的激发，从而实现低频信号通信的可行性和有效性。

The present invention discloses a long-wave communication system and method based on a vibrating beam. The system comprises: a signal generator configured to generate an excitation signal and vibrate according to the excitation signal to drive a radiation source device to vibrate; a radiation source device configured to generate a time-varying magnetic field; and a signal receiver configured to sense the time-varying magnetic field, generate an induced electromotive force, and perform data processing on the induced electromotive force to achieve communication. By analyzing the dynamic characteristics of a permanent magnet mechanical antenna, the present invention demonstrates the feasibility and effectiveness of using a small-sized mechanical antenna to excite low-frequency signals, thereby achieving low-frequency signal communication.

Description

Vibration beam-based long-wave communication system and method thereof
Technical Field
The invention relates to the technical field of mechanical antennas, in particular to a vibration beam-based long-wave communication system and a method thereof.
Background
In the traditional wireless communication field, long wave communication needs to be matched with a large-size signal transmitting antenna, so that the application of the long wave communication on a small-sized platform is restricted.
The low-frequency electromagnetic wave has longer wavelength, has the characteristics of long propagation distance, strong penetrability, slow attenuation and the like, and can be widely applied to the fields of underwater communication, navigation, positioning and the like. The size of a conventional antenna depends on the wavelength of electromagnetic waves, so for a low frequency antenna, the antenna is bulky and the device is complex.
Currently, mechanical antennas can be classified into three types, electret type, permanent magnet type and piezoelectric type, according to different electromagnetic wave excitation modes. The radiation intensity of the electret mechanical antenna is closely related to the charge density, and it is difficult to increase the charge density of the electret surface. Piezoelectric mechanical antennas are limited by the size of the piezoelectric material and have a limited radiating area. The radiation intensity of the permanent magnet type mechanical antenna is higher than that of other two schemes in the near field range by means of the higher magnetic residue of the NdFeB permanent magnet.
Since frequency modulation is less affected by external noise, frequency modulation is the best choice in terms of mechanical antenna signal modulation. The cantilever beam has a simple structure and a complex mode, and can generate complex electromagnetic waves by utilizing the multi-mode vibration characteristic of the cantilever beam structure and combining with the permanent magnet.
Disclosure of Invention
The invention aims to provide a vibration beam-based long-wave communication system and a vibration beam-based long-wave communication method, which are used for realizing the excitation of low-frequency signals by using a small-size mechanical antenna by analyzing the dynamic characteristics of a permanent magnet mechanical antenna, so that the feasibility and the effectiveness of the low-frequency signal communication are realized.
The technical scheme for solving the technical problems is as follows:
The invention provides a vibration beam-based long-wave communication system, which comprises:
The signal generation device is used for generating an excitation signal and vibrating according to the excitation signal so as to drive the radiation source device to vibrate;
a radiation source device for generating a time-varying magnetic field;
The signal receiving device is used for inducing the time-varying magnetic field, generating induced electromotive force and carrying out data processing on the induced electromotive force so as to realize communication;
The radiation source device is constructed as a three degree of freedom return beam structure and includes:
The rigid connecting piece is vertically arranged and provided with a first connecting end and a second connecting end which are opposite to each other along the height extending direction,
The first beam part comprises a first beam body which is perpendicular to the height extending direction of the rigid connecting piece and comprises a fixed end and a turning part, wherein the fixed end is fixedly arranged, and the fixed surface of the turning part is used for fixing the first connecting end;
The second beam part is arranged in parallel with the first beam part and comprises a third connecting end and a free end, the third connecting end is fixed on the second connecting end, and the free end is arranged close to the fixed end;
The second beam part comprises a plurality of beam bodies which are arranged in parallel, and the free end of each beam body is provided with a permanent magnet.
Optionally, the first beam body is further provided with a ceramic piezoelectric plate, and one end of the ceramic piezoelectric plate is flush with the fixed end.
Optionally, the second beam part comprises a second beam body and a third beam body which are arranged in parallel, a first permanent magnet is arranged on the free end of the second beam body, and a second permanent magnet is arranged on the free end of the third beam body.
Optionally, the signal generating device comprises a function generator, a power amplifier and a piezoelectric sensor which are connected in sequence, wherein the function generator is used for generating the voltage and the frequency of the excitation signal;
the power amplifier is used for amplifying the voltage of the excitation signal to obtain an excitation voltage;
The piezoelectric sensor is used for receiving the excitation voltage and generating vibration according to the excitation voltage so as to drive the radiation source device to vibrate.
Optionally, the signal receiving device comprises a coil, an oscilloscope and a data processing module, wherein the coil is used as a signal receiving end to induce a time-varying magnetic field generated by the vibration of the permanent magnet so as to generate induced electromotive force;
the oscilloscope is used for receiving and storing the induced electromotive force and sending the induced electromotive force to the data processing module;
the data processing module is used for carrying out encoding and decoding processing on the induced electromotive force so as to realize communication.
The invention also provides a vibration beam-based long-wave communication method, which is based on the vibration beam-based long-wave communication system and comprises the following steps:
s1, a control signal generating device generates an excitation signal;
S2, amplifying the voltage of the excitation signal to obtain an excitation voltage;
s3, receiving the excitation voltage by using a piezoelectric sensor, and generating vibration according to the excitation voltage so as to drive the radiation source device to vibrate;
s4, controlling the radiation source device to generate a time-varying magnetic field according to vibration;
S5, generating induced electromotive force according to the time-varying magnetic field;
And S6, carrying out data processing on the induced electromotive force so as to realize communication.
Optionally, the step S5 includes:
S51, determining the magnetic field intensity according to the vibration displacement;
And S52, obtaining the induced electromotive force according to the magnetic field intensity, the turns of the coil and the sectional area of the coil.
Alternatively, the vibration displacement in the step S51 is obtained by:
A1, constructing a quality matrix and a rigidity matrix of the three-degree-of-freedom foldback beam structure according to the three-degree-of-freedom foldback beam structure;
A2, determining a vibration motion equation of the three-degree-of-freedom foldback beam structure according to the mass matrix and the rigidity matrix;
A3, calculating equivalent concentrated force of the ceramic piezoelectric plate on the three-degree-of-freedom foldback beam structure under the excitation of the current excitation voltage;
A4, obtaining vibration displacement of the rigid connecting piece and vibration displacement of the permanent magnet under the excitation of the current excitation voltage according to the vibration motion equation and the equivalent concentrated force;
in the step A2, the vibration motion equation of the three-degree-of-freedom folded beam structure is as follows:
Wherein M 1 represents the mass of the rigid connection member, M 2 represents the mass of the first permanent magnet, M 3 represents the mass of the second permanent magnet, C ij represents the related component in the damping matrix and the damping matrix is c=αm+βk, M represents the mass matrix of the three-degree-of-freedom folded beam structure, K represents the stiffness matrix of the three-degree-of-freedom folded beam structure, α, β are the mass damping coefficient and the stiffness damping coefficient, y 1、y2 and y 3 represent the displacements of the rigid connection member, the first permanent magnet and the second permanent magnet in the vertical direction, respectively, AndRespectively represent the speeds of the connecting piece, the first permanent magnet and the second permanent magnet in the vertical direction,AndAcceleration of the connecting piece, the first permanent magnet and the second permanent magnet in the vertical direction is respectively expressed, and F (t) represents equivalent concentrated force of the ceramic piezoelectric sheet on the three-degree-of-freedom foldback beam structure;
In the step A3, an equivalent concentration force F (t) of the ceramic piezoelectric sheet on the three-degree-of-freedom folded beam structure is:
wherein M represents the strain generated by the ceramic piezoelectric plate acting on the first beam body to cause the bending moment generated by the first beam body to be equal to Epsilon represents the strain generated by the ceramic piezoelectric sheet under the excitation of the current excitation voltage u (t) =A isin(2πfi t andΔl is the deformation of the ceramic piezoelectric sheet, L is the length of the ceramic piezoelectric sheet, h p is the thickness of the ceramic piezoelectric sheet, d 31 is the piezoelectric constant of the ceramic piezoelectric sheet, A i is the excitation voltage amplitude, pi is the circumference ratio, f i is the frequency of the excitation voltage, t is the excitation time, E 1 is the elastic modulus of the first beam, I 1 is the moment of inertia of the first beam, h 1 is the thickness of the first beam, and L 1 is the length of the first beam.
Optionally, in the step S51, the magnetic field strength B is:
Wherein μ 0 denotes a vacuum permeability, m denotes a magnetic dipole moment, b denotes an ordinate of any point P (a, b) in space, y (t) denotes a vibration displacement, a denotes an abscissa of any point P (a, b) in space, and pi denotes a circumferential rate;
in the step S52, the induced electromotive force U is:
Where N a denotes the number of turns of the coil, ψ denotes the magnetic flux through the coil and ψ=ba a,Aa denotes the coil cross-sectional area, B denotes the magnetic field strength and Mu 0 represents vacuum permeability, m represents magnetic dipole moment, b represents P point y-axis coordinate, y (t) represents vibration displacement, a represents P point x-axis coordinate, pi represents circumference ratio, and t represents excitation time.
Optionally, the step S6 includes:
s61, taking the maximum value of the induced electromotive force as the signal intensity;
And S62, judging whether the signal intensity of each permanent magnet is equal to the signal intensity of the rigid connecting piece, if so, proceeding to step S63, otherwise, adjusting the current excitation voltage value and returning to step S1.
S63, coding the frequency and time information of the excitation signal to obtain coded data;
and S64, decoding the encoded information by using an SLs signal analysis method to realize communication.
The invention has the following beneficial effects:
1) The invention provides a three-degree-of-freedom foldback beam structure based on inverse piezoelectric effect, vibration permanent magnet type mechanical antenna radiation theory and low-frequency electromagnetic wave communication principle, thereby obtaining the relation between the front third-order inherent frequency of the foldback beam structure and the magnetic field intensity of a vibration permanent magnet;
2) The invention utilizes the relation between the vibration displacement of the permanent magnet and the induced electromotive force of the receiving end to obtain the relation between the excitation voltages of excitation signals with different frequencies;
3) The invention combines the inverse piezoelectric effect, electromagnetics and vibration mechanics to realize the excitation of the low-frequency band signals by using the small-size mechanical antenna, thereby realizing the feasibility and the effectiveness of the low-frequency signal communication.
Drawings
Fig. 1 is a schematic structural diagram of a vibration beam-based long wave communication system according to the present invention;
FIG. 2 is a schematic view of a three degree of freedom return beam structure according to the present invention;
FIG. 3 is a flow chart of a vibration beam-based long wave communication method of the present invention;
FIG. 4 is a graph showing the displacement of the rigid connection, the first permanent magnet and the second permanent magnet of the present invention at different excitation frequencies;
FIG. 5 is a signal strength calculation flow chart;
FIG. 6 is a schematic diagram of the theoretical result signal processing result;
FIG. 7 is a schematic diagram of the result of excitation voltage optimization theory signal processing.
Description of the reference numerals
1-Rigid connecting piece, 11-first connecting end, 12-second connecting end, 2-first beam body, 21-fixed end, 22-turning part, 23-ceramic piezoelectric plate, 31-third connecting end, 32-free end, 33-second beam body, 34-third beam body, 35-first permanent magnet and 36-second permanent magnet.
Detailed Description
The principles and features of the present invention are described below with reference to the drawings, the examples are illustrated for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention.
The present invention provides a vibration beam-based long wave communication system, which is shown with reference to fig. 1, and includes:
The signal generation device is used for generating an excitation signal and vibrating according to the excitation signal so as to drive the radiation source device to vibrate;
a radiation source device for generating a time-varying magnetic field;
The signal receiving device is used for inducing the time-varying magnetic field, generating induced electromotive force and carrying out data processing on the induced electromotive force so as to realize communication;
the radiation source device is constructed as a three-degree-of-freedom return beam structure and is shown with reference to fig. 2 ((a) front view, (b) top view), the three-degree-of-freedom return beam structure comprising:
A rigid connection member 1, the rigid connection member 1 being disposed vertically and having a first connection end 11 and a second connection end 12 disposed opposite to each other in a height extending direction thereof,
A first beam part, the first beam part comprises a first beam body 2, the first beam body 2 is arranged perpendicular to the height extending direction of the rigid connecting piece 1, and comprises a fixed end 21 and a turning part 22, the fixed end 21 is fixedly arranged, and the fixed surface of the turning part 22 is used for fixing the first connecting end 11;
A second beam portion disposed parallel to the first beam portion and including a third connection end 31 and a free end 32, the third connection end 31 being fixed to the second connection end 12, the free end 32 being disposed proximate to the fixed end 21;
The second beam part comprises a plurality of beam bodies which are arranged in parallel, and the free end of each beam body is provided with a permanent magnet.
In the present invention, the second beam portion includes a second beam body 33 and a third beam body 34 disposed in parallel, a first permanent magnet 35 is disposed on a free end 32 of the second beam body 33, and a second permanent magnet 36 is disposed on the free end 32 of the third beam body 34. Of course, the number of the beam bodies of the second beam portion can be specifically set by those skilled in the art in combination with the present invention and practical situations, and the present invention is not limited thereto.
Optionally, a ceramic piezoelectric plate 23 is further disposed on the first beam 2, and one end of the ceramic piezoelectric plate 23 is flush with the fixed end 21.
According to the three-degree-of-freedom foldback beam structure, the inverse piezoelectric effect of the ceramic piezoelectric plate 23 is utilized, amplified alternating voltage is applied to the ceramic piezoelectric plate 23, so that the ceramic piezoelectric plate 23 is deformed, the first beam body 2 is driven to vibrate, and the first permanent magnet 35 and the second permanent magnet 36 also vibrate along with the second beam body 33 and the third beam body 34. Finally, the receiving-end coil receives the superimposed magnetic field generated by the vibration of the first permanent magnet 35 and the second permanent magnet 36 to realize communication.
Optionally, the signal generating device comprises a function generator, a power amplifier and a piezoelectric sensor which are connected in sequence, wherein the function generator is used for generating the voltage and the frequency of the excitation signal;
the power amplifier is used for amplifying the voltage of the excitation signal to obtain an excitation voltage;
The piezoelectric sensor is used for receiving the excitation voltage and generating vibration according to the excitation voltage so as to drive the radiation source device to vibrate.
Optionally, the signal receiving device comprises a coil, an oscilloscope and a data processing module, wherein the coil is used as a signal receiving end to induce a time-varying magnetic field generated by the vibration of the permanent magnet so as to generate induced electromotive force;
the oscilloscope is used for receiving and storing the induced electromotive force and sending the induced electromotive force to the data processing module;
the data processing module is used for carrying out encoding and decoding processing on the induced electromotive force so as to realize communication.
The invention also provides a vibration beam-based long-wave communication method, which is shown in fig. 3, and is based on the vibration beam-based long-wave communication system, and comprises the following steps:
s1, a control signal generating device generates an excitation signal;
S2, amplifying the voltage of the excitation signal to obtain an excitation voltage;
s3, receiving the excitation voltage by using a piezoelectric sensor, and generating vibration according to the excitation voltage so as to drive the radiation source device to vibrate;
Specifically, the voltage and the frequency of the excitation signal are generated through the function generator, the voltage of the excitation signal is amplified through the power amplifier, and then the piezoelectric sensor vibrates after receiving the excitation voltage, so that the radiation source (namely the three-degree-of-freedom foldback beam) is driven to vibrate.
S4, controlling the radiation source device to generate a time-varying magnetic field according to vibration;
since the radiation source device comprises the permanent magnet, the vibration of the permanent magnet is influenced by time and voltage changes in the vibration process, so that a time-varying magnetic field is generated.
S5, generating induced electromotive force according to the time-varying magnetic field;
optionally, the step S5 includes:
S51, determining the magnetic field intensity according to the vibration displacement;
The magnetic field strength B is as follows:
Wherein μ 0 denotes a vacuum permeability, m denotes a magnetic dipole moment, b denotes an ordinate of any point P (a, b) in space, y (t) denotes a vibration displacement, a denotes an abscissa of any point P (a, b) in space, and pi denotes a circumference ratio.
The vibration displacement in the step S51 is obtained by:
A1, constructing a quality matrix and a rigidity matrix of the three-degree-of-freedom foldback beam structure according to the three-degree-of-freedom foldback beam structure;
A2, determining a vibration motion equation of the three-degree-of-freedom foldback beam structure according to the mass matrix and the rigidity matrix;
In the present invention, in order to conveniently analyze the vibration frequency response of the three-degree-of-freedom folded beam structure, the mass matrix M of the three-degree-of-freedom folded beam structure is:
where m 1 represents the mass of the rigid connection 1, m 2 represents the mass of the first permanent magnet 35, and m 3 represents the mass of the second permanent magnet 36.
Similarly, the rigidity matrix K of the three-degree-of-freedom folded beam structure is obtained according to a standard rigidity influence coefficient method in material mechanics, and is as follows:
wherein k ij represents the relevant component in the stiffness matrix and A 1、A2、A3、B1、B2、B3、C1、C2、C3 and D are both intermediate parametersE 1、E2 and E 3 are the elastic moduli of the first beam 2, the second beam 33, and the third beam 34, respectively, I 1、I2 and I 3 are the moments of inertia of the first beam 2, the second beam 33, and the third beam 34, respectively, and L 1、L2 and L 3 are the lengths of the first beam 2, the second beam 33, and the third beam 34, respectively.
Parameters of the components of the three degree of freedom return beam structure of the present invention are set forth in table 1.
TABLE 1 parameters related to the structure of the return beam
Besides, the natural frequency and the vibration mode of the three-degree-of-freedom system equation K=ω 2 M are obtained by solving the eigenvalue of the three-degree-of-freedom system equation K=ω 2 M.
Table 2 shows the first third order mode vectors, and the first third order natural frequency theoretical values are f 1＝11.5Hz、f2 =12.6 Hz and f 3 =22.0 Hz, respectively. It can be seen from table 2 that the first-order vibration mode in which the amplitudes of the first permanent magnet 35 and the second permanent magnet 36 are the same and significantly larger than the rigid coupling member 1, the second-order vibration mode in which the amplitudes of the rigid coupling member 1 are almost zero, the amplitudes of the first permanent magnet 35 and the second permanent magnet 36 are equal, and the phases are 180 ° different, and the third-order vibration mode in which the amplitudes of the first permanent magnet 35 and the second permanent magnet 36 are the same and smaller than the amplitude of the rigid coupling member 1.
Vibration mode vector of table 2 structure
S2, determining a vibration motion equation of the three-degree-of-freedom foldback beam structure according to the mass matrix and the rigidity matrix;
The vibration motion equation of the three-degree-of-freedom foldback beam structure is as follows:
Wherein M 1 represents the mass of the rigid connection member, M 2 represents the mass of the first permanent magnet, M 3 represents the mass of the second permanent magnet, C ij represents the related component in the damping matrix and the damping matrix is c=αm+βk, M represents the mass matrix of the three-degree-of-freedom folded beam structure, K represents the stiffness matrix of the three-degree-of-freedom folded beam structure, α, β are the mass damping coefficient and the stiffness damping coefficient, y 1、y2 and y 3 represent the displacements of the rigid connection member, the first permanent magnet and the second permanent magnet in the vertical direction, respectively, AndRespectively represent the speeds of the connecting piece, the first permanent magnet and the second permanent magnet in the vertical direction,AndAcceleration of the connecting piece, the first permanent magnet and the second permanent magnet in the vertical direction is respectively expressed, and F (t) represents equivalent concentrated force of the ceramic piezoelectric sheet on the three-degree-of-freedom foldback beam structure.
A3, calculating equivalent concentrated force of the ceramic piezoelectric plate on the three-degree-of-freedom foldback beam structure under the excitation of the current excitation voltage;
The equivalent concentrated force F (t) of the ceramic piezoelectric plate on the three-degree-of-freedom foldback beam structure is as follows:
wherein M represents the strain generated by the ceramic piezoelectric plate acting on the first beam body to cause the bending moment generated by the first beam body to be equal to Epsilon represents the strain generated by the ceramic piezoelectric sheet under the excitation of the current excitation voltage u (t) =A isin(2πfi t andΔl is the deformation of the ceramic piezoelectric sheet, L is the length of the ceramic piezoelectric sheet, h p is the thickness of the ceramic piezoelectric sheet, d 31 is the piezoelectric constant of the ceramic piezoelectric sheet, A i is the excitation voltage amplitude, pi is the circumference ratio, f i is the frequency of the excitation voltage, t is the excitation time, E 1 is the elastic modulus of the first beam, I 1 is the moment of inertia of the first beam, h 1 is the thickness of the first beam, and L 1 is the length of the first beam.
A4, obtaining vibration displacement of the rigid connecting piece and vibration displacement of the permanent magnet under the excitation of the current excitation voltage according to the vibration motion equation and the equivalent concentrated force;
The fourth-order Longer-Kutta method (Runge-Kutta methods) has high calculation accuracy and accurate data, so that the vibration motion equation is solved by adopting the method and equivalent concentrated force. The step length of each step of calculation is 0.005, the frequency of the excitation signal of the ceramic piezoelectric plate 23 is the first three-order natural frequency of the three-degree-of-freedom reentrant beam structure, and when the frequency is 11.5Hz, 12.6Hz and 22.0Hz in sequence, the corresponding excitation time is 0-40 s, 40-80 s and 80-120 s respectively. The parameters used in the three degree of freedom return beam structure are as in table 3, solving for the displacements of the rigid connection member 1, the first permanent magnet 35 and the second permanent magnet 36.
TABLE 3 parameter values used in displacement calculation
The displacements y 1、y2 and y 3 of the mass 1, the permanent magnets 2 and 3 are shown in fig. 4. As is clear from fig. 4 (a) 11.5Hz, (b) 12.6Hz, and (c) 22.0Hz, the displacements of the rigid connection member 1, the first permanent magnet 35, and the second permanent magnet 36 at the former third-order natural frequency agree with the vibration modes (see table 2).
And S52, obtaining the induced electromotive force according to the magnetic field intensity, the turns of the coil and the sectional area of the coil.
In the invention, the receiving device of the low-frequency electromagnetic wave is a coil, which is positioned on the y-axis, and according to Faraday electromagnetic induction law, if the coil is positioned in a time-varying magnetic field of a transmitting antenna, the coil generates induced electromotive force with the same frequency, and therefore, the induced electromotive force U is as follows:
Where N a denotes the number of turns of the coil, ψ denotes the magnetic flux through the coil and ψ=ba a,Aa denotes the coil cross-sectional area, B denotes the magnetic field strength and Mu 0 represents vacuum permeability, m represents magnetic dipole moment, b represents P point y-axis coordinate, y (t) represents vibration displacement, a represents P point x-axis coordinate, pi represents circumference ratio, and t represents excitation time.
And S6, carrying out data processing on the induced electromotive force so as to realize communication.
Optionally, the step S6 includes:
s61, taking the maximum value of the induced electromotive force as the signal intensity;
And S62, judging whether the signal intensity of each permanent magnet is equal to the signal intensity of the rigid connecting piece, if so, proceeding to step S63, otherwise, adjusting the current excitation voltage value and returning to step S1.
S63, coding the frequency and time information of the excitation signal to obtain coded data;
and S64, decoding the encoded information by using an SLs signal analysis method to realize communication.
In order to facilitate the decoding process of the received signal, the intensity of the received signal needs to be guaranteed to be consistent, and in fig. 6 (b), the color shade represents the intensity of the signal. It can be seen that the strength of the signals of the second and third frequencies is significantly smaller than that of the first, and the signals of the second and third frequencies may be regarded as noise during actual communication, which is disadvantageous for the receiving end to decode the received signals. According to the above scheme, the excitation voltage determines the magnitude of the vibration displacement of the permanent magnet, and the strength of the induced electromotive force at the receiving end is related to the vibration displacement of the permanent magnet, thus, according to the vibration motion equation and formulaThe relationship between the strength of the induced electromotive force at the receiving end and the excitation voltage can be determined.
It should be noted that, when a i is adjusted, u (t) also changes accordingly, referring to fig. 5, because u (t) =a isin(2πfi t) is actually the magnitude of the excitation voltage.
The invention is analyzed on the basis of the following theory:
For a vibrating mechanical antenna, frequency modulation of electromagnetic waves can be achieved by controlling the frequency of vibration of a permanent magnet. The formulated transmission protocol is shown in table 4, and the first third-order vibration frequencies f 1、f2 and f 3 of the prescribed three-degree-of-freedom folded beam represent "1" code, "2" code and "3" code, respectively. The time domain lengths t 1＝10s、t2 = 15s and t 3 = 5s of the signal represent a "1" code and a "2" code, respectively, and the absence of an excitation signal at time t 3 indicates that one information code ends, and one information code contains three sets of frequency-time combinations.
Table 4 transmission protocol for mechanical antenna communication
Let the amplitude of the excitation voltage a 1＝A2＝A3 =200v, bring y 2 and y 3 into the formulaThe induced electromotive force due to the time-varying magnetic field generated by the vibration of the permanent magnet can be derived. In transmitting information, the frequency and the time domain length of the excitation signal are as shown in table 5, and one information code is defined every 40s, and a total of 4 information codes are defined. According to the transmission protocol of table 4, the theoretical induced electromotive forces generated by the coils receiving the first permanent magnet 35 and the second permanent magnet 36 are converted into information codes [ '112132', '211231', '123121', '312211' ] for transmission, as shown in the induced electromotive force diagram of fig. 6 (a), it can be seen that there are 4 distinct periodic signals.
TABLE 5 frequency and time Domain Length of excitation signals
And processing the signal received by the receiving end coil based on the SLs signal analysis method to obtain time-frequency information of the signal, as shown in a time-frequency diagram of the signal in fig. 6 (b). According to the magnitude of the signal frequency and the time domain length of the signal in fig. 6 (b), 4 groups of information codes which are the same as the transmitting end can be obtained, and the feasibility of realizing low-frequency electromagnetic wave communication through a mechanical antenna is theoretically verified.
In the calculation process, the excitation voltage amplitude a 1 =200v corresponding to the first-order excitation frequency f 1 and the corresponding signal strength P 1＝1.2×10-4 are taken, according to the flow of fig. 5, a 2＝525V,A3 =612V is obtained, the signal strength is shown in the signal strength diagram of fig. 7 (a), and as can be seen from the diagram, when the mechanical antenna structure vibrates stably, the signal strengths of the frequencies f 1、f2 and f 3 are the same, and are about p=1.2x10 -4. And then, according to the transmission signals of the table 5, the received induced electromotive force is processed by adopting SLs signals to obtain a signal time-frequency diagram, as shown in the signal time-frequency diagram of fig. 7 (b), compared with fig. 6 (b), the color depths of the signals corresponding to f 1、f2 and f 3 are consistent, the signal strength is the same, and the optimized excitation voltage value is utilized for communication, so that the receiving end is more beneficial to decoding the received information.
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims (9)

1.一种基于振动梁的长波通信系统，其特征在于，所述基于振动梁的长波通信系统包括：1. A long-wave communication system based on a vibration beam, characterized in that the long-wave communication system based on a vibration beam comprises: 信号发生装置，所述信号发生装置用于生成激励信号，并根据所述激励信号进行振动，以带动辐射源装置进行振动；a signal generating device, the signal generating device being configured to generate an excitation signal and vibrate according to the excitation signal to drive the radiation source device to vibrate; 辐射源装置，所述辐射源装置用于生成时变磁场；a radiation source device, the radiation source device being used to generate a time-varying magnetic field; 信号接收装置，所述信号接收装置用于感应所述时变磁场，生成感应电动势，并对所述感应电动势进行数据处理，以实现通信；a signal receiving device configured to sense the time-varying magnetic field, generate an induced electromotive force, and perform data processing on the induced electromotive force to achieve communication; 所述辐射源装置构造为三自由度折返梁结构且包括：The radiation source device is constructed as a three-degree-of-freedom folding beam structure and includes: 刚性连接件，所述刚性连接件竖直设置且沿其高度延伸方向上具有彼此相对设置的第一连接端和第二连接端，A rigid connector, the rigid connector being vertically arranged and having a first connecting end and a second connecting end opposite to each other along a height extension direction thereof, 第一梁部，所述第一梁部包括第一梁体，所述第一梁体垂直于所述刚性连接件的高度延伸方向设置，且包括固定端和折返部，所述固定端固定设置，所述折返部的固定面用于固定所述第一连接端；a first beam portion, the first beam portion including a first beam body, the first beam body being arranged perpendicular to the height extension direction of the rigid connector and including a fixed end and a folded portion, the fixed end being fixedly arranged, and the fixed surface of the folded portion being used to fix the first connecting end; 第二梁部，所述第二梁部与所述第一梁部平行设置且包括第三连接端和自由端，所述第三连接端固定于所述第二连接端，所述自由端靠近所述固定端设置；a second beam portion, the second beam portion being arranged parallel to the first beam portion and comprising a third connecting end and a free end, the third connecting end being fixed to the second connecting end, and the free end being arranged close to the fixed end; 所述第二梁部包括平行设置的多个梁体，各梁体的自由端均设置有永磁体；The second beam portion includes a plurality of beam bodies arranged in parallel, and a permanent magnet is provided at the free end of each beam body; 所述生成感应电动势包括：Generating the induced electromotive force comprises: 根据振动位移，确定磁场强度；Determine the magnetic field strength based on the vibration displacement; 根据所述磁场强度、线圈的匝数及其截面积，得到感应电动势；Obtaining an induced electromotive force according to the magnetic field strength, the number of turns of the coil and its cross-sectional area; 所述振动位移通过以下方式得到：The vibration displacement is obtained by: A1：根据所述三自由度折返梁结构，构建三自由度折返梁结构的质量矩阵和刚度矩阵；A1: Based on the three-degree-of-freedom reentrant beam structure, construct a mass matrix and a stiffness matrix of the three-degree-of-freedom reentrant beam structure; A2：根据所述质量矩阵和所述刚度矩阵，确定三自由度折返梁结构的振动运动方程；A2: Determine the vibration motion equation of the three-degree-of-freedom reentrant beam structure based on the mass matrix and the stiffness matrix; A3：计算当前激励电压激励下，陶瓷压电片对所述三自由度折返梁结构的等效集中力；A3: Calculate the equivalent concentrated force of the ceramic piezoelectric plate on the three-degree-of-freedom foldback beam structure under the current excitation voltage; A4：根据所述振动运动方程和所述等效集中力，得到当前激励电压激励下的刚性连接件的振动位移以及永磁体的振动位移。A4: According to the vibration motion equation and the equivalent concentrated force, the vibration displacement of the rigid connector and the vibration displacement of the permanent magnet under the current excitation voltage are obtained. 2.根据权利要求1所述的基于振动梁的长波通信系统，其特征在于，所述第一梁体上还设置有陶瓷压电片，所述陶瓷压电片的一端与所述固定端平齐。2. The long-wave communication system based on a vibration beam according to claim 1 is characterized in that a ceramic piezoelectric sheet is further provided on the first beam body, and one end of the ceramic piezoelectric sheet is flush with the fixed end. 3.根据权利要求1所述的基于振动梁的长波通信系统，其特征在于，所述第二梁部包括平行设置的第二梁体和第三梁体，所述第二梁体的自由端上设置有第一永磁体，所述第三梁体的自由端上设置有第二永磁体。3. The long-wave communication system based on a vibration beam according to claim 1 is characterized in that the second beam portion includes a second beam body and a third beam body arranged in parallel, a first permanent magnet is arranged on the free end of the second beam body, and a second permanent magnet is arranged on the free end of the third beam body. 4.根据权利要求1所述的基于振动梁的长波通信系统，其特征在于，所述信号发生装置包括依次连接的函数发生器、功率放大器和压电传感器，所述函数发生器用于产生激励信号的电压和频率；4. The long-wave communication system based on a vibration beam according to claim 1, wherein the signal generating device comprises a function generator, a power amplifier, and a piezoelectric sensor connected in sequence, wherein the function generator is used to generate the voltage and frequency of the excitation signal; 所述功率放大器用于对所述激励信号的电压进行放大，得到激励电压；The power amplifier is used to amplify the voltage of the excitation signal to obtain an excitation voltage; 所述压电传感器用于接收所述激励电压，并根据所述激励电压产生振动，以带动所述辐射源装置振动。The piezoelectric sensor is used to receive the excitation voltage and generate vibration according to the excitation voltage to drive the radiation source device to vibrate. 5.根据权利要求1-4中任意一项所述的基于振动梁的长波通信系统，其特征在于，所述信号接收装置包括线圈、示波器和数据处理模块，所述线圈作为信号接收端以对所述永磁体振动产生的时变磁场进行感应，生成感应电动势；5. The long-wave communication system based on a vibration beam according to any one of claims 1 to 4, wherein the signal receiving device comprises a coil, an oscilloscope, and a data processing module, wherein the coil serves as a signal receiving end to sense the time-varying magnetic field generated by the vibration of the permanent magnet to generate an induced electromotive force; 所述示波器用于接收和存储所述感应电动势，并将所述感应电动势发送至数据处理模块；The oscilloscope is used to receive and store the induced electromotive force, and send the induced electromotive force to the data processing module; 所述数据处理模块用于对所述感应电动势进行编码和解码处理，以实现通信。The data processing module is used to encode and decode the induced electromotive force to achieve communication. 6.一种基于振动梁的长波通信方法，其特征在于，所述基于振动梁的长波通信方法基于权利要求1-5中任意一项所述的基于振动梁的长波通信系统，且所述基于振动梁的长波通信方法包括：6. A long-wave communication method based on a vibration beam, characterized in that the long-wave communication method based on a vibration beam is based on the long-wave communication system based on a vibration beam according to any one of claims 1 to 5, and the long-wave communication method based on a vibration beam comprises: S1：控制信号发生装置生成激励信号；S1: Control signal generating device to generate excitation signal; S2：对所述激励信号的电压进行放大，得到激励电压；S2: amplifying the voltage of the excitation signal to obtain an excitation voltage; S3：利用压电传感器接收所述激励电压，并根据所述激励电压产生振动，以带动所述辐射源装置振动；S3: using a piezoelectric sensor to receive the excitation voltage and generate vibration according to the excitation voltage to drive the radiation source device to vibrate; S4：控制所述辐射源装置根据振动生成时变磁场；S4: controlling the radiation source device to generate a time-varying magnetic field according to the vibration; S5：根据所述时变磁场，生成感应电动势；S5: generating an induced electromotive force according to the time-varying magnetic field; S6：对所述感应电动势进行数据处理，以实现通信。S6: Performing data processing on the induced electromotive force to achieve communication. 7.根据权利要求6所述的基于振动梁的长波通信方法，其特征在于，所述A2中，所述三自由度折返梁结构的振动运动方程为：7. The long-wave communication method based on a vibration beam according to claim 6, wherein in A2, the vibration motion equation of the three-degree-of-freedom folded-back beam structure is: 其中，表示刚性连接件的质量，表示第一永磁体的质量，表示第二永磁体的质量，表示阻尼矩阵中的相关分量，且阻尼矩阵为，表示三自由度折返梁结构的质量矩阵，表示三自由度折返梁结构的刚度矩阵，分别是质量阻尼系数和刚度阻尼系数，、和分别表示刚性连接件、第一永磁体和第二永磁体在竖直方向的位移，、和分别表示连接件、第一永磁体和第二永磁体在竖直方向的速度，、和分别表示连接件、第一永磁体和第二永磁体在竖直方向的加速度，表示陶瓷压电片对所述三自由度折返梁结构的等效集中力；in, represents the mass of the rigid connector, represents the mass of the first permanent magnet, represents the mass of the second permanent magnet, represents the relevant components in the damping matrix, and the damping matrix is , represents the mass matrix of the three-degree-of-freedom folded-back beam structure, represents the stiffness matrix of the three-degree-of-freedom folded-back beam structure, are the mass damping coefficient and the stiffness damping coefficient, 、 and denote the vertical displacements of the rigid connector, the first permanent magnet, and the second permanent magnet, respectively. 、 and are the vertical velocities of the connecting member, the first permanent magnet, and the second permanent magnet, respectively. 、 and represent the vertical accelerations of the connecting member, the first permanent magnet, and the second permanent magnet, respectively, represents the equivalent concentrated force of the ceramic piezoelectric plate on the three-degree-of-freedom folding beam structure; 所述A3中，所述陶瓷压电片对所述三自由度折返梁结构的等效集中力为：In A3, the equivalent concentrated force of the ceramic piezoelectric sheet on the three-degree-of-freedom folding beam structure for: 其中，表示陶瓷压电片产生的应变作用在第一梁体上，使得第一梁体产生的弯矩，且，表示陶瓷压电片在当前激励电压的激励下产生的应变，且，为陶瓷压电片变形量；为陶瓷压电片的长度，为陶瓷压电片的厚度，表示陶瓷压电片的压电常数，表示激励电压幅值，为圆周率，表示激励电压的频率，表示激励时间，表示第一梁体的弹性模量，表示第一梁体的转动惯量，表示第一梁体的厚度，表示第一梁体的长度。in, represents the strain generated by the ceramic piezoelectric sheet acting on the first beam, causing the first beam to generate a bending moment, and , Indicates the current excitation voltage of the ceramic piezoelectric piece The strain generated by the excitation, and , is the deformation of the ceramic piezoelectric piece; is the length of the ceramic piezoelectric piece, is the thickness of the ceramic piezoelectric sheet, represents the piezoelectric constant of the ceramic piezoelectric piece, represents the excitation voltage amplitude, is pi, represents the frequency of the excitation voltage, Indicates the incentive time, represents the elastic modulus of the first beam, represents the moment of inertia of the first beam, represents the thickness of the first beam, Indicates the length of the first beam. 8.根据权利要求6所述的基于振动梁的长波通信方法，其特征在于，所述磁场强度为：8. The long wave communication method based on a vibration beam according to claim 6, wherein the magnetic field strength for: 其中，表示真空磁导率，表示磁偶极矩，表示空间中任意一点P(a, b)的纵坐标，表示振动位移，表示空间中任意一点P(a, b)的横坐标，表示圆周率；in, represents the vacuum permeability, represents the magnetic dipole moment, represents the ordinate of any point P(a, b) in space, represents the vibration displacement, represents the horizontal coordinate of any point P(a, b) in space, represents pi; 所述感应电动势为：The induced electromotive force for: 其中，表示线圈的匝数，表示通过线圈的磁通量且，表示线圈截面积，表示磁场强度，且，表示真空磁导率，表示磁偶极矩，表示空间中任意一点P(a, b)的纵坐标，表示振动位移，表示空间中任意一点P(a, b)的横坐标，表示圆周率，表示激励时间。in, Indicates the number of turns of the coil, represents the magnetic flux through the coil and , represents the cross-sectional area of the coil, represents the magnetic field strength, and , represents the vacuum permeability, represents the magnetic dipole moment, represents the ordinate of any point P(a, b) in space, represents the vibration displacement, represents the horizontal coordinate of any point P(a, b) in space, represents pi, Indicates the incentive time. 9.根据权利要求6-8中任意一项所述的基于振动梁的长波通信方法，其特征在于，所述步骤S6包括：9. The long wave communication method based on a vibration beam according to any one of claims 6 to 8, wherein step S6 comprises: S61：将所述感应电动势中的最大值作为信号强度；S61: taking the maximum value of the induced electromotive force as the signal strength; S62：判断所述各所述永磁体的信号强度和刚性连接件的信号强度是否相等，若是，进入步骤S63，否则，调整当前激励电压值并返回步骤S1；S62: Determine whether the signal strength of each permanent magnet is equal to the signal strength of the rigid connector. If so, proceed to step S63; otherwise, adjust the current excitation voltage value and return to step S1; S63：将所述激励信号的频率和时间信息进行编码，得到编码数据；S63: Encode the frequency and time information of the excitation signal to obtain encoded data; S64：利用SLs信号分析方法对所述编码数据进行解码，以实现通信。S64: Decode the encoded data using the SLs signal analysis method to achieve communication.
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