A method for generating acoustic waves of an optimal matching frequency of a target soil and an adaptive ring-shaped central excitation acoustic source module
By dynamically matching the soil acoustic impedance using an adaptive ring-shaped central excitation sound source module, the problem of soil structure affecting point measurement methods is solved, achieving efficient and accurate soil moisture content detection, and reducing equipment costs and installation complexity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHIHEZI UNIVERSITY
- Filing Date
- 2026-04-07
- Publication Date
- 2026-06-12
AI Technical Summary
In existing technologies, point measurement or sampling measurement methods are affected by the location of the sampling point and the soil structure, resulting in low accuracy of soil moisture content measurement for the entire plot area. In addition, the equipment is difficult to install, has a high deployment density, and is costly.
An adaptive ring-shaped central excitation sound source module is adopted. The soil environmental reference parameters are obtained through the control unit, and impedance matching instructions and sound wave design instructions are generated. By utilizing the synergistic work of the PZT excitation ring and magnetorheological elastomer material, the soil acoustic impedance is dynamically matched, and the target sound wave is generated for detection.
It enables rapid, accurate, and wide-ranging reflection of soil moisture content changes at the plot level, improving the accuracy and reliability of measurements while reducing equipment costs and installation complexity.
Smart Images
Figure CN122183918A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of soil testing technology, and in particular to a method for generating sound waves with the optimal matching frequency for target soil and an adaptive ring-shaped central excitation sound source module. Background Technology
[0002] With the development of precision agriculture, agricultural production has placed higher demands on soil moisture content detection methods. Traditional soil moisture content detection methods, such as resistance methods, capacitance methods (including time-domain and frequency-domain methods), and spectroscopic methods, are mostly point-based or sampling measurements. These methods reflect the soil moisture content at the sampling and measurement locations to some extent, but the results of these point-based and sampling measurements are affected by factors such as the distribution of sampling points, terrain elevation, and soil structure characteristics, and cannot accurately reflect changes in regional soil moisture content in practical applications. The development of modern smart agriculture requires rapid reflection of changes in soil moisture content at the plot level to guide irrigation decisions. However, existing point-based and sampling methods for soil moisture content detection suffer from problems such as difficult equipment installation, high deployment density, high cost, and unreasonable measurement methods.
[0003] Sound waves, as a non-destructive, green, safe, and low-cost detection method, have great application potential in the field of soil moisture detection. Utilizing low-frequency sound waves to detect farmland soil moisture content is a new technological trend, as soil moisture content is a key factor affecting the propagation of sound waves in porous soil media. Higher water content alters soil density and elastic modulus, leading to faster sound wave propagation speed and increased attenuation (absorption and scattering). Vibration-distributed fiber optic acoustic sensing (DAS) technology can achieve large-scale, efficient detection of farmland soil moisture content; however, this technology requires an underground excitation sound source capable of efficiently, stably, and controllably emitting low-frequency sound waves horizontally and adaptively matching the acoustic impedance of complex soils. In related technologies, the emitted low-frequency sound waves cannot match the acoustic impedance of complex soils, resulting in low accuracy in measuring soil moisture content across the entire plot.
[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention
[0005] The main objective of this application is to provide a method for generating sound waves with the optimal matching frequency for the target soil and an adaptive ring-shaped central excitation sound source module. This aims to solve the problem that in the prior art, the measurement results of point measurement or sampling measurement are affected by the location of the sampling point and the soil structure, resulting in low accuracy of soil moisture content measurement for the entire plot area.
[0006] The first aspect of this application provides a method for generating sound waves with the optimal matching frequency for target soil, applied to an adaptive ring-shaped center-excited sound source module, the adaptive ring-shaped center-excited sound source module including a control unit, an external sensor, a vibration excitation unit, and a vibration isolation protection unit; The method for generating the acoustic wave with the optimal matching frequency for the target soil includes: The control unit acquires environmental baseline parameters of the target soil collected by the external sensors; The control unit generates impedance matching instructions and acoustic wave design instructions based on the environmental reference parameters. The control unit adjusts the vibration isolation protection unit to the target state according to the impedance matching command; The control unit controls the vibration excitation unit to generate target sound waves according to the sound wave design instructions, so as to transmit the target sound waves to the target soil through the vibration isolation protection unit in the target state.
[0007] Optionally, in one embodiment of this application, the environmental reference parameters include soil temperature, initial moisture content, and burial depth pressure; The generation of impedance matching instructions and acoustic wave design instructions based on the environmental reference parameters specifically includes: The average acoustic impedance is calculated based on the soil temperature, the initial moisture content, and the burial depth pressure. Impedance matching instructions and acoustic wave design instructions are generated based on the average acoustic impedance.
[0008] Optionally, in one embodiment of this application, the step of calculating the average acoustic impedance based on the soil temperature, the initial moisture content, and the burial depth pressure specifically includes: The soil temperature, the initial moisture content, and the burial depth pressure are input into the soil acoustic model, and the soil density and soil sound velocity are output. The average acoustic impedance of the target soil is calculated based on the soil density and the soil sound velocity.
[0009] Optionally, in one embodiment of this application, the step of generating impedance matching instructions and acoustic wave design instructions based on the average acoustic impedance specifically includes: The target stiffness required for acoustic impedance matching of the zoom coupling cavity is calculated based on the average acoustic impedance, the target current applied to the global ring electromagnetic coil is obtained based on the target stiffness, and an impedance matching command is generated based on the target current. The target radial distance of the target soil is determined based on the average acoustic impedance, and the target excitation parameters of the PZT excitation ring are obtained based on the target radial distance. The acoustic wave design command is then generated based on the target excitation parameters.
[0010] Optionally, in one embodiment of this application, the step of controlling the vibration excitation unit to generate the target sound wave according to the sound wave design instructions further includes: The real-time vibration data of the target soil collected by the external sensor is acquired, and the real-time vibration data is compared with the target excitation parameters to obtain the deviation value characteristics; The determination result is made based on the deviation value characteristics, and the average acoustic impedance generation impedance matching command or acoustic wave design command is corrected based on the determination result.
[0011] The second aspect of this application also provides an adaptive ring-shaped center-excited sound source module for implementing the method described in any one of the above solutions, wherein the adaptive ring-shaped center-excited sound source module includes a control unit, an external sensor, a vibration excitation unit, and a vibration isolation protection unit; The control unit is connected to the vibration excitation unit, the vibration isolation protection unit and the external sensor respectively. The vibration isolation protection unit is connected to the outside of the vibration excitation unit, and the outer wall of the vibration isolation protection unit is used to contact the soil to be tested. The external sensor is used to collect environmental baseline parameters and real-time vibration feedback of the target soil. The control unit is used to generate impedance matching instructions and acoustic design instructions based on the environmental reference parameters, correct the impedance matching instructions and acoustic design instructions based on the real-time vibration feedback, and send the impedance matching instructions to the vibration isolation protection unit and the acoustic design instructions to the vibration excitation unit. The vibration isolation protection unit is used to adjust to the target state according to the impedance matching command; The vibration excitation unit is used to generate a target sound wave according to the sound wave design command, so as to transmit the target sound wave to the target soil through the vibration isolation protection unit in the target state.
[0012] Optionally, in one embodiment of this application, the control unit is a main control drive circuit, the external sensors include an environmental sensor array and a vibration feedback sensor, the vibration isolation protection unit includes an acoustic impedance matching zoom coupling cavity and a global ring electromagnetic inductance, and the vibration excitation unit includes a PZT excitation ring and a harmonic generator. The environmental sensor array, the vibration feedback sensor, the acoustic impedance matching zoom coupling cavity, and the global annular electromagnetic inductance are respectively connected to the main control drive circuit. The global annular electromagnetic inductance is arranged around the acoustic impedance matching zoom coupling cavity, and the vibration feedback sensor is arranged inside the PZT excitation ring.
[0013] Optionally, in one embodiment of this application, the adaptive ring-shaped center excitation sound source module further includes a power amplifier, which is connected to the main control drive circuit and is correspondingly arranged with the PZT excitation ring; the PZT excitation ring includes multiple sets of ring-arranged curved PZT sheets.
[0014] Optionally, in one embodiment of this application, the adaptive ring-shaped central excitation sound source module further includes a housing, the central portion of the vibration excitation unit is mounted on the housing, and the housing is in the shape of an inverted hat.
[0015] Optionally, in one embodiment of this application, the environmental sensor array includes multiple burial depth pressure sensors, soil moisture sensors, and soil temperature sensors. The multiple burial depth pressure sensors are all disposed on the top of the encapsulation housing, and the soil moisture sensors and the soil temperature sensors are located outside the acoustic impedance matching zoom coupling cavity.
[0016] Beneficial effects: This application provides a method for generating acoustic waves with the optimal matching frequency for target soil and an adaptive ring-shaped central excitation acoustic source module. This application works in concert with the dynamic impedance matching of MRE and the phased array zoom of PZT, which can dynamically adapt to non-uniform soil conditions and effectively detect different radial depths. It can quickly, accurately and over a wide range reflect the changes in soil moisture content in plot-level areas, thus improving the accuracy and reliability of the measurement. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a cross-sectional view of a preferred embodiment of the adaptive ring-shaped central excitation sound source module of this application; Figure 2 This is an overall structural diagram of a preferred embodiment of the adaptive ring-shaped center-excited sound source module of this application; Figure 3 This is a schematic diagram of the PZT excitation ring in a preferred embodiment of the adaptive ring center excitation sound source module of this application; Figure 4 This is a schematic diagram of the vibration isolation protection unit in a preferred embodiment of the adaptive ring center excitation sound source module of this application; Figure 5This is a schematic diagram of the power amplifier unit in a preferred embodiment of the adaptive ring center excitation sound source module of this application; Figure 6 This is a schematic diagram of the encapsulation housing in a preferred embodiment of the adaptive ring center excitation sound source module of this application; Figure 7 A flowchart of a preferred embodiment of the acoustic wave generation method for the target soil of this application with the optimal matching frequency; Figure 8 This is a flowchart illustrating the specific implementation steps of the sound wave generation method for the optimal matching frequency of the target soil in this application, in a preferred embodiment of the entire execution process.
[0019] Explanation of reference numerals in the attached figures: 1. Vibration excitation unit; 11. PZT excitation ring; 111. PZT group; 112. Outer rigid ring; 113. Inner rigid ring; 12. Harmonic generator; 2. Vibration isolation protection unit; 21. Acoustic impedance matching zoom coupling cavity; 22. Global ring electromagnetic coil; 3. Power amplification unit; 31. Main control drive circuit; 32. Power amplifier; 4. External sensor; 41. Environmental sensor array; 42. Vibration feedback sensor; 5. Encapsulation shell.
[0020] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation
[0021] To make the objectives, technical solutions, and effects of this application clearer and more explicit, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only possible technical implementations of this application and not all possible implementations. Based on the embodiments in this application, those skilled in the art can obtain other embodiments without creative effort, and these embodiments are also within the protection scope of this application.
[0022] First, the terms used in the embodiments of this application will be introduced: DAS, Distributed Acoustic Sensing; MRE, Magneto-Rheological Elastomer; PZT, Lead Zirconate Titanate, is a piezoelectric ceramic (often simply called piezoelectric ceramic). S-AIZCC, Sound Impedance Matching Zoom Coupling Cavity; DSP stands for Digital Signal Processor.
[0023] The technical solutions of this application will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.
[0024] like Figure 1 , Figure 2 and Figure 3 As shown in the preferred embodiment of this application, the adaptive ring-shaped center-excited sound source module is used to realize the sound wave generation method of the adaptive ring-shaped center-excited sound source module. The adaptive ring-shaped center-excited sound source module includes a control unit, an external sensor 4, a vibration excitation unit 1, and a vibration isolation protection unit 2. The control unit is connected to the vibration excitation unit 1, the vibration isolation protection unit 2, and the external sensor 4 respectively. The vibration isolation protection unit 2 is connected to the outside of the vibration excitation unit 1, and the outer wall of the vibration isolation protection unit 2 is used to contact the soil to be tested. The external sensor 4 is used to collect environmental reference parameters and real-time vibration feedback of the target soil; the control unit is used to generate impedance matching instructions and acoustic wave design instructions according to the environmental reference parameters, correct the impedance matching instructions and acoustic wave design instructions according to the real-time vibration feedback, and send the impedance matching instructions to the vibration isolation protection unit 2 and the acoustic wave design instructions to the vibration excitation unit 1; the vibration isolation protection unit 2 is used to adjust to the target state according to the impedance matching instructions; the vibration excitation unit 1 is used to generate target acoustic waves according to the acoustic wave design instructions, so as to transmit the target acoustic waves to the target soil through the vibration isolation protection unit 2 in the target state.
[0025] The adaptive ring-shaped center-excited sound source module of this application includes: a vibration excitation unit 1, a vibration isolation protection unit 2, a power amplification unit 3 (the control unit is located in the power amplification unit 3), an external sensor 4, and a housing 5; wherein, the vibration excitation unit 1 is used to generate controllable low-frequency mechanical vibration; the vibration isolation protection unit 2 is used to focus sound energy and match adaptive acoustic impedance, ensuring maximum and optimal propagation of low-frequency mechanical vibration while protecting crop roots and surface crops from vibration interference; the power amplification unit 3 is used to amplify the excitation digital signal and drive the control device; the external sensor 4 is used to provide reference parameters of the environment around the sound source; the housing 5 is used to protect the internal components and ensure that the sound source can be buried for a long time.
[0026] In one embodiment of this application, the adaptive ring center excitation sound source module further includes a power amplifier 32, which is connected to the main control drive circuit 31 and is correspondingly arranged with the PZT excitation ring 11; the PZT excitation ring 11 includes multiple sets of ring-arranged curved PZT sheets.
[0027] Specifically, see Figure 3 , Figure 4 and Figure 5 The adaptive ring-shaped center-excited acoustic source module includes: a vibration excitation unit, a vibration isolation protection unit, a power amplifier unit, an external sensor, and a housing. The vibration excitation unit includes a ring of curved PZT sheets for generating horizontal radial mechanical vibration parallel to the ground. The vibration isolation protection unit includes an acoustic impedance-matched zoom coupling cavity (S-AIZCC) made of magnetorheological elastomer (MRE) solid material, whose outer surface is in direct contact with the soil. It also includes a global ring-shaped electromagnetic coil for applying a magnetic field, the coil being arranged around the periphery of the S-AIZCC. The power amplifier unit includes a main control drive circuit and a power amplifier. The main control drive circuit (DSP) is configured to: a) receive soil environmental parameters from the external sensor and predict the average acoustic impedance Z of the target soil. soil b) Calculate and output commands to control the DC current (IC) of the global loop electromagnetic coil. DC To achieve the acoustic impedance Z of S-AIZCC S-AIZCC With Z soil Dynamic matching; c) Generating an excitation signal containing fundamental and higher harmonic components, and controlling the phase of the multi-channel excitation signal of the PZT excitation ring ( ) and amplitude ( ( ), to achieve horizontal phase-controlled zoom of sound waves.
[0028] Specifically, the global loop electromagnetic coil 22 is further configured to superimpose alternating current to fine-tune the dynamic viscoelastic damping characteristics of the MRE coupling cavity.
[0029] The external sensor array 4 includes a burial depth pressure sensor located on top of the encapsulation housing 5, and a multi-point soil moisture sensor and soil temperature sensor located outside the S-AIZCC coupling cavity for direct contact with the soil.
[0030] The vibration excitation unit 1 also includes a harmonic generator 12, which is integrated into the main control drive circuit 31. The harmonic generator 12 generates second and third higher harmonic components for soil nonlinear analysis by digital synthesis or nonlinear drive waveform, and superimposes them into the excitation signal.
[0031] In one embodiment of this application, the control unit is a main control drive circuit 31, the external sensor 4 includes an environmental sensor array 41 and a vibration feedback sensor 42, the vibration isolation protection unit 2 includes an acoustic impedance matching zoom coupling cavity 21 and a global annular electromagnetic inductance line, and the vibration excitation unit 1 includes a PZT excitation ring 11 and a harmonic generator 12; the environmental sensor array 41, the vibration feedback sensor 42, the acoustic impedance matching zoom coupling cavity 21 and the global annular electromagnetic inductance line are respectively connected to the main control drive circuit 31, the global annular electromagnetic inductance line is arranged around the acoustic impedance matching zoom coupling cavity 21, and the vibration feedback sensor 42 is arranged inside the PZT excitation ring 11.
[0032] In one embodiment of this application, see Figure 6 The adaptive ring-shaped central excitation sound source module also includes a housing 5, and the central part of the vibration excitation unit 1 is mounted on the housing 5. The housing 5 is in the shape of an inverted hat.
[0033] In one embodiment of this application, the environmental sensor array 41 includes multiple burial depth pressure sensors, soil moisture content sensors, and soil temperature sensors. The multiple burial depth pressure sensors are all disposed on the top of the encapsulation housing 5, and the soil moisture content sensors and the soil temperature sensors are located outside the acoustic impedance matching zoom coupling cavity 21.
[0034] Specifically, the vibration excitation unit 1 includes a PZT excitation ring 11 and a harmonic generator 12, which are arranged in a ring-shaped symmetrical structure with eight sets of piezoelectric ceramics stacked together. This structure is located in the middle of the adaptive ring-shaped central excitation sound source module and connected to the power amplifier unit 3. It is used to generate controllable low-frequency mechanical vibration. The PZT excitation ring 11 includes eight sets of PZT groups 111. The vibration isolation protection unit 2 includes an acoustic impedance matching zoom coupling cavity 21 and a global ring electromagnetic coil 22. It has a flat ring-shaped solid coupling structure, wraps around the outside of the vibration excitation unit 1 and is in direct contact with the soil. It is connected to the power amplifier unit 3 and used to focus... The system includes a joule sound energy and a matching adaptive acoustic impedance; a power amplification unit 3, including a power amplifier 32 and a main control drive circuit 31, is located above the vibration excitation unit 1 and is used to amplify the excitation digital signal and drive the control device; an external sensor 4, including an environmental sensor array 41 and a vibration feedback sensor 42, is connected to the power amplification unit 3 and is used to provide environmental reference parameters of the soil; and a housing 5, which has an inverted hat-shaped structure, is located in the center of the vibration excitation unit 1 and on top of the entire adaptive ring center excitation sound source module to protect the internal components and ensure that the sound source can be buried for a long time.
[0035] Understandably, external sensor 4 is the source of information, and environmental sensor array 41 collects soil temperature and humidity (external information) and transmits it to the main control drive circuit 31. Power amplifier unit 3 is the central hub for information processing. The DSP receives the information, runs the soil acoustic model, predicts the soil acoustic impedance Zsoil and the required detection parameters, and generates two sets of instructions: an impedance matching instruction (IDC) sent to the electromagnetic coil; and an acoustic wave design instruction (phase, amplitude) sent to the PZT excitation ring 11. Vibration feedback sensor 42 forms an information loop. Vibration feedback sensor 42 monitors actual vibration and transmits the "real-time" data back to the DSP. The DSP compares the "real-time" data with the "instructions," and if a deviation is found, it immediately corrects the instructions sent to the electromagnetic coil or PZT ring.
[0036] It is worth noting that the power amplifier 32 obtains signals from the DSP to provide energy to the PZT excitation ring 11. The DSP designs the acoustic wave (including the fundamental and harmonic frequencies), which is amplified by the power amplifier 32 to drive the PZT excitation ring 11 to generate mechanical vibration. The vibration isolation protection unit 2 surrounds the vibration excitation unit 1. The PZT ring vibrates, and the vibration is transmitted to the outer MRE coupling cavity. At this time, the stiffness of the MRE coupling cavity has been adjusted by the DSP through the electromagnetic coil to match the soil, and the vibration energy is smoothly transmitted to the soil through the coupling cavity. Throughout the entire energy conversion and transmission process, the encapsulation shell 5 isolates external moisture and pressure, ensuring that the PZT, MRE, and circuit board can operate stably.
[0037] The PZT excitation ring 11 consists of eight groups of bent piezoelectric ceramic sheets arranged in a ring array. Each group consists of 5 to 10 layers of ceramic sheets. PZT (Lead Zirconate Titanate) is selected as the piezoelectric ceramic material. The PZT element is fixed between the inner and outer rigid rings 112 and is located in the middle of the adaptive ring center excitation sound source module. It is connected to the power amplification unit 3 and is used to generate controllable low-frequency mechanical vibration to achieve horizontal beamforming and acoustic zoom of the sound wave. The harmonic generator 12 is set on the circuit board of the main control drive circuit 31 and integrated into the circuit board. It is used to superimpose second and third harmonic components into the PZT drive signal to generate harmonic signals for soil nonlinear attenuation analysis and medium characteristic inversion, making it most suitable for DAS fiber reception, demodulation and subsequent signal processing.
[0038] The acoustic impedance matching zoom coupling cavity 21 is made of environmentally friendly magnetorheological elastomer (MRE). The MRE contains uniformly distributed magnetic particles in a flat, ring-shaped structure, which wraps around the PZT excitation ring 11 and is connected to the main control drive circuit 31 in the power amplification unit 3. This allows for dynamic adjustment of the acoustic impedance of the acoustic impedance matching zoom coupling cavity 21 to approximate the acoustic impedance of the soil, maximizing and optimizing sound wave energy emission. Specifically, applying an external magnetic field to the MRE causes reversible changes in its shear modulus, Young's modulus, and damping coefficient, altering the local stiffness and shape of the acoustic impedance matching zoom coupling cavity 21, thus achieving acoustic zoom and local impedance matching. The global annular electromagnetic coil 22 is uniformly circumferentially surrounding the acoustic impedance matching zoom coupling cavity 21. It is used to adjust the DC current of the annular electromagnetic coil by controlling the magnetic field, thereby adjusting the stiffness of the acoustic impedance matching zoom coupling cavity 21 and achieving efficient coupling of sound wave energy.
[0039] The power amplifier 32 corresponds to the PZT excitation ring 11 and is used to amplify digital signals and output them to the PZT excitation ring 11. The main control drive circuit 31 has a built-in high-performance DSP (Digital Signal Processor) and is used to output digital signals to the power amplifier 32 for amplification, control the PZT excitation ring 11, output control signals to control the magnetic field to adjust the global ring electromagnetic coil 22, drive the external sensor 4, and process the integrated signals it collects.
[0040] The environmental sensor array 41 is disposed on the outer sidewall of the acoustic impedance matching zoom coupling cavity 21, symmetrically arranged at four azimuth angles, and in direct contact with the soil. It is used to provide environmental reference parameters of the soil, which are key input data for the main control drive circuit 31 to perform acoustic impedance matching and MRE stiffness adjustment. The vibration feedback sensor 42 is disposed inside the outer rigid ring 112 of the PZT excitation ring 11, close to the acoustic impedance matching zoom coupling cavity 21. It is used to provide actual vibration feedback of the PZT excitation ring 11 and the acoustic impedance matching zoom coupling cavity 21, for closed-loop control and real-time calibration of the main control drive circuit 31, to ensure the accuracy of the emitted sound waves.
[0041] The encapsulation shell 5 has an inverted hat-shaped structure, with the main body made of high-strength engineering plastic. It is located in the center of the vibration excitation unit 1 and on top of the entire adaptive ring-shaped central excitation sound source module. All seams are multi-sealed, providing IP68 waterproof and pressure-resistant capabilities to protect internal components and prevent soil moisture and corrosive substances from intruding, ensuring the sound source can be buried for a long time. The top of the encapsulation shell 5 is equipped with a waterproof sealed connector, leading out power and data communication lines to the DAS control center on the ground, providing a stable power supply and high-speed data link to receive task commands and transmit equipment status.
[0042] In this embodiment of the application, an adaptive ring-shaped central vibration sound source module for detecting soil moisture content in farmland includes a vibration excitation unit 1, a vibration isolation protection unit 2, a power amplification unit 3, an external sensor 4, and a packaging shell 5. The external sensor 4 includes an environmental sensor array 41 and a vibration feedback sensor 42. The environmental sensor array 41 is disposed on the outer sidewall of the acoustic impedance matching zoom coupling cavity 21 and is symmetrically arranged at four azimuth angles. The vibration feedback sensor 42 is disposed inside the outer rigid ring 112 of the PZT excitation ring 11, close to the acoustic impedance matching zoom coupling cavity 21, with the inner rigid ring 113 corresponding to the outer rigid ring 12. Both are connected to the power amplification unit 3 to provide environmental reference parameters of the soil and actual vibration feedback. The power amplification unit 3 is disposed above the vibration excitation unit 1 and includes a main... The control drive circuit 31 and power amplifier 32 are used to amplify the excitation digital signal, control the magnetic field, and drive the control device. The vibration isolation protection unit 2, which is wrapped around the outside of the vibration excitation unit 1 and in direct contact with the soil, includes an acoustic impedance matching zoom coupling cavity 21 and a global ring electromagnetic coil 22. It is connected to the main control drive circuit 31 in the power amplifier unit 3 and is used to focus the acoustic energy and match the adaptive impedance. The vibration excitation unit 1 is located in the middle of the adaptive ring center excitation sound source module. The PZT excitation ring 11 and the harmonic generator 12 are connected to the power amplifier unit 3 and are used to generate controllable low-frequency mechanical vibration. The encapsulation shell is located in the central part of the vibration excitation unit and on the top of the entire adaptive ring center excitation sound source module to protect the internal components and ensure that the sound source can be buried for a long time.
[0043] In this embodiment, the main control drive circuit estimates the acoustic impedance of the surrounding soil based on environmental reference parameters of the soil around the sound source collected by the external sensor array, and then calculates the acoustic impedance Z of the matching zoom coupling cavity. S-AIZC The required reference stiffness of the MRE elastomer is obtained by calculating the DC current I that controls the global magnetic field. DCThe magnetic field is controlled to adjust the global stiffness of the acoustic impedance matching zoom coupling cavity, achieving dynamic matching between its acoustic impedance and the soil acoustic impedance. The main control drive circuit generates an excitation signal for the PZT excitation ring according to the set detection task, synchronously triggering the power amplifier to drive the PZT excitation ring to emit low-frequency mechanical vibration. The vibration feedback sensor detects the actual vibration output of the sound source in real time and compares it with the excitation parameters for closed-loop calibration. The working principle of the adaptive ring-shaped central vibration sound source module for detecting farmland soil moisture content in this embodiment is as follows: Its core working principle is to use the multi-physics field coordinated control of PZT piezoelectric effect and MRE magnetorheological effect to achieve horizontal ring-efficiency coupling, precise emission and adaptive zoom of low frequency sound wave energy in soil.
[0044] The specific working mechanism involves the adaptive ring-shaped central excitation sound source module starting up, followed by the environmental sensor array acquiring real-time data on soil temperature T, initial moisture content H, and burial pressure P. b The high-performance DSP controller inside the main control drive circuit predicts or estimates the average acoustic impedance Z of the soil source based on these parameters and the built-in soil acoustic model. soil Soil acoustic impedance ;in The density of the soil medium being tested, The speed of sound; to maximize the transmission of sound wave energy to the soil, the acoustic impedance needs to be matched with the acoustic impedance Z of the zoom coupling cavity. S-AIZCC With Z soil Match as closely as possible. The DSP bases its predictions on Z... soil The target stiffness required for acoustic impedance matching of the zoom coupling cavity is calculated. A precisely adjusted DC current I is applied to the global toroidal electromagnetic coil via a magnetic field control system. DC The current generates a magnetic field B, which alters the arrangement of magnetic particles inside the MRE elastomer, thereby dynamically adjusting the effective shear modulus G of the MRE. MRE and viscoelasticity; among which, ; The dynamic modulus is a function of the magnetic field strength B. It is the density of MRE; therefore, by adjusting I DC Optimize B to make Z S-AIZCC Dynamic approximation of Z soil This maximizes the transmission of acoustic energy. The DSP generates coded excitation pulses containing the fundamental frequency f0 and the required second and third harmonics. These pulses drive the PZT excitation loop via a power amplifier. To achieve acoustic zoom, the DSP precisely calculates and controls the phase of the excitation signal for each independent unit in the PZT excitation loop. and amplitude By adjusting the phase difference between PZT units This allows sound waves to form a directional beam in the horizontal plane and focus at a certain radial distance R from the sound source, improving the signal-to-noise ratio for long-distance detection. A vibration feedback sensor monitors the actual vibration state of the PZT excitation ring in real time and feeds the data back to the DSP. If the actual vibration does not match the target, the DSP immediately fine-tunes the magnetic field strength of the MRE or the excitation parameters of the PZT to perform transient impedance mismatch compensation and beam correction. The global magnetic field adjustment MRE provides broad impedance adaptation, while the phased-array drive of the PZT array provides precise horizontal beam control. Together, after the signal is received by the DAS fiber, it is transmitted back to the surface control center for further analysis of soil moisture content and iterative optimization of the sound source's emission strategy.
[0045] The preferred embodiment of this application describes a method for generating acoustic waves at the optimal matching frequency for the target soil, such as... Figure 7 As shown, the method for generating sound waves at the optimal matching frequency for the target soil includes the following steps: In step S10, the control unit acquires the environmental baseline parameters of the target soil collected by the external sensor.
[0046] In one possible implementation, the environmental reference parameters include soil temperature, initial moisture content, and burial pressure. Step S10 specifically includes: calculating the average acoustic impedance based on the soil temperature, the initial moisture content, and the burial pressure; and generating impedance matching instructions and acoustic wave design instructions based on the average acoustic impedance.
[0047] Specifically, the calculation of the average acoustic impedance is achieved by inputting the soil temperature, the initial moisture content, and the burial depth pressure into the soil acoustic model, and outputting the soil density and soil sound velocity; and calculating the average acoustic impedance of the target soil based on the soil density and the soil sound velocity.
[0048] Specifically, the main control drive circuit (DSP) activates and reads data from the external sensor array. The collected parameters include: soil temperature (T), as temperature affects the speed of sound propagation in the medium and the elastic modulus of the soil; initial moisture content (H), which is the basis for the inversion of the core target and the most critical variable affecting soil density and acoustic impedance; and burial pressure (P0), as different depths of soil experience different overburden pressures, leading to different soil compaction (density), thus affecting acoustic impedance. The DSP inputs the collected real-time data into its internal pre-set soil acoustic model. The DSP stores a large number of empirical formulas or algorithmic models that describe how temperature, moisture content, and pressure jointly affect two key physical quantities of the soil: soil density (generally, higher moisture content and higher pressure result in higher density) and soil sound velocity (the speed at which sound waves propagate in the soil, significantly affected by moisture content and soil structure). Based on the calculated soil density and soil sound velocity, the average acoustic impedance of the target soil is calculated. Note that the average acoustic impedance calculated here is not the final soil moisture content result displayed to the user, but rather an intermediate control target.
[0049] In step S20, the control unit generates impedance matching instructions and acoustic wave design instructions based on the environmental reference parameters.
[0050] In one possible implementation, the specific implementation of generating impedance matching instructions and acoustic wave design instructions is as follows: calculate the target stiffness required for acoustic impedance matching zoom coupling cavity based on the average acoustic impedance, obtain the target current applied to the global ring electromagnetic coil based on the target stiffness, and generate impedance matching instructions based on the target current; determine the target radial distance of the target soil based on the average acoustic impedance, obtain the target excitation parameters of the PZT excitation ring based on the target radial distance, and generate acoustic wave design instructions based on the target excitation parameters.
[0051] Specifically, the DSP reverse-engineers the required stiffness and viscosity of the MRE (magnetorheological elastomer) based on the acoustic impedance of the target soil. The DSP then calculates the required magnetic field (B) to generate this stiffness based on the MRE stiffness-magnetic field strength relationship (through a pre-calibrated database). Finally, the DSP calculates the required DC current to be supplied to the electromagnetic coil to generate this magnetic field based on the magnetic field-current relationship.
[0052] Specifically, by inputting soil acoustic impedance, soil density, and sound velocity, the DSP will assess the attenuation of sound waves at different frequencies based on predicted soil characteristics (especially moisture content H). Generally, higher frequencies attenuate faster (less far); lower frequencies have stronger penetration, but resolution may decrease. If the data shows that the soil is very wet (high H, high Zsoil), the sound waves attenuate quickly, and the DSP may choose a lower fundamental frequency (e.g., 100Hz) to ensure detection distance. If the soil is drier, the attenuation is smaller, and a slightly higher frequency (e.g., 500Hz) may be chosen to obtain better resolution. This determines the fundamental frequency.
[0053] Input the soil sound velocity, and the time delay = distance difference / sound velocity. The core principle of phased array focusing is time delay. If the soil is very wet and the sound velocity is high, then for the same distance difference, the required time delay is small; if the soil is very dry and the sound velocity is slow, then for the same distance difference, the required time delay is large. This determines the phase.
[0054] Given the soil acoustic impedance Zsoil, the DSP estimates the initial energy required to reach the target distance R based on the magnitude of Zsoil. If Zsoil indicates significant soil attenuation, the DSP may instruct the power amplifier to output a larger amplitude (An) to compensate for propagation loss and ensure a high signal-to-noise ratio over long distances. This determines the amplitude.
[0055] In step S30, the control unit adjusts the vibration isolation protection unit to the target state according to the impedance matching command.
[0056] Specifically, the DSP sends a command to the power amplifier unit, outputting a precisely calculated DC current to the global toroidal electromagnetic coil. The coil, energized, generates a magnetic field (B), which acts on the MRE coupling cavity encased in the PZT. Understandably, the magnetic field alters the arrangement of the magnetic particles inside the MRE (from disordered to ordered, or changes the interaction forces between the particles), thus instantaneously changing the macroscopic mechanical properties of the MRE. Consequently, the acoustic impedance of the MRE coupling cavity is adjusted to be close to the average acoustic impedance.
[0057] In step S40, the control unit controls the vibration excitation unit to generate a target sound wave according to the sound wave design command, so as to transmit the target sound wave to the target soil through the vibration isolation protection unit in the target state.
[0058] Specifically, the DSP transmits the generated multi-channel excitation pulses (containing the phase, amplitude, fundamental frequency, and harmonic components of each PZT group) to the power amplifier. The DSP sends a precise synchronous trigger signal, which the power amplifier instantly amplifies, driving all eight ceramic plates in the PZT excitation ring to vibrate simultaneously according to the preset phase and amplitude. The PZT ceramic plates generate horizontal radial mechanical vibration parallel to the ground; the vibration is transmitted to the tightly attached MRE coupling cavity (whose stiffness has been adjusted by S20 to match the soil), and then efficiently transmitted to the surrounding soil, forming sound waves that propagate horizontally in all directions. At the same moment as the PZT vibration, the vibration feedback sensor, which is attached to the inner side of the rigid ring on the outer side of the PZT excitation ring, begins to work.
[0059] After step S40, the method further includes: acquiring real-time vibration data of the target soil collected by the external sensor, comparing the real-time vibration data with the target excitation parameters to obtain deviation value characteristics; determining the judgment result based on the deviation value characteristics, and correcting the average acoustic impedance generation impedance matching command or acoustic wave design command based on the judgment result.
[0060] Specifically, the SP receives the actual vibration data transmitted from the vibration feedback sensor, compares the actual data with the set target excitation parameters item by item, and calculates the deviation value. Based on the characteristics of the deviation value, the DSP intelligently determines the nature of the problem: if the overall energy weakens or the frequency shifts, it is determined to be a transient impedance mismatch, meaning that the sound wave energy is obstructed when entering the soil through the MRE coupling cavity, possibly due to a sudden change in soil moisture or dryness causing a change in impedance; if the beam direction deviates or the focal point shifts, it is determined to be a beam deviation, meaning that the sound wave does not propagate in the predetermined direction, possibly due to local soil inhomogeneity causing changes in sound velocity, or differences in the PZT unit response. Based on the determination result, the DSP executes the corresponding correction instructions: if it is a transient impedance mismatch, the DSP immediately sends a command to the global loop electromagnetic coil to fine-tune the DC current (IDC), quickly change the stiffness of the MRE, compensate for the impedance change, and allow energy to be transmitted smoothly again; if it is a beam deviation, the DSP immediately recalculates, fine-tunes the phase of the excitation signal of the PZT excitation ring, corrects the beam direction, and allows the sound wave to return to the predetermined direction.
[0061] This application achieves horizontal ring-shaped acoustic wave transmission, perfectly suited for applications where the device is buried in the center of farmland and received by DAS around the perimeter. It employs MRE solid damping medium and magnetic field control, significantly improving structural reliability and robustness, eliminating the risk of leakage from liquid damping medium, and being more environmentally friendly. Combining the global impedance adaptation of MRE with the phased array zoom of PZT, this application achieves dynamic and precise acoustic impedance matching and acoustic zoom functions, effectively overcoming soil heterogeneity and enabling multi-radial depth detection. The entire set of electronic components in this application is highly integrated, with a compact structure, suitable for farmland environments where crops grow.
[0062] See Figure 8 The specific implementation of this application will be described below in conjunction with a specific application scenario.
[0063] K1. Environmental Perception and Impedance Prediction: Collect environmental baseline parameters of the soil surrounding the sound source and predict the average acoustic impedance Z of the target soil. soil Specifically, the adaptive ring-shaped central excitation sound source module is buried underground at the geometric center of the farmland. Upon system startup, the main control drive circuit collects environmental reference parameters of the soil surrounding the sound source via an external sensor array, including: soil temperature T, initial moisture content H, and burial depth pressure P0. Based on the data collected by the external sensor array, the control drive circuit estimates the average acoustic impedance Z of the target soil. soil Then, the acoustic impedance Z of the zoom coupling cavity that achieves acoustic impedance matching is calculated. S-AIZCC ≈Z soil The required MRE elastomer reference stiffness is determined, and the corresponding global magnetic field DC current I is calculated. DC ; K2 and MRE stiffness matching: based on Z soil Determine the required global magnetic field DC current I DC Adjust the DC current of the global loop electromagnetic coil to I DC To achieve the acoustic impedance Z of the MRE coupled cavity S-AIZCC With Z soil Dynamic matching; specifically, the main control drive circuit outputs control commands to adjust the DC current of the global ring electromagnetic coil to I by controlling the magnetic field. DC By changing the global stiffness of the acoustic impedance matching zoom coupling cavity, dynamic matching between its acoustic impedance and the soil acoustic impedance can be achieved. K3, PZT phased excitation: The phase of the multi-channel excitation signal of the PZT excitation loop is determined according to the phased array principle. ) and amplitude ( The system generates coded excitation pulses containing higher harmonic components. The main control drive circuit determines the fundamental frequency f0, waveform, electronic harmonic components and amplitude of the PZT excitation ring according to the set detection task (such as the radial distance R of the target farmland soil), generates multi-channel excitation signals, and synchronously triggers the power amplifier. The fundamental frequency range of the generated excitation pulse is 100Hz~500Hz, and the superimposed higher harmonic components mainly include the second harmonic and the third harmonic. K4. Coordinated emission and real-time feedback: The PZT excitation ring is synchronously driven to emit horizontal ring sound waves, while the actual vibration output is detected in real time by a vibration feedback sensor; that is, the PZT excitation ring is driven to emit low-frequency mechanical vibrations, and the vibration feedback sensor detects the actual vibration output of the sound source in real time. K5. Closed-Loop Calibration: The main control drive circuit compares the vibration feedback data with the target excitation parameters, determines transient impedance mismatch or sound beam deviation, and performs closed-loop calibration of the magnetic field strength of the MRE and the excitation parameters of the PZT excitation loop. If transient impedance mismatch is determined, the DC current I of the global loop electromagnetic coil is finely adjusted. DC The stiffness of the MRE is adjusted transiently; if it is determined to be beam deviation, the phase of the excitation signal of the PZT excitation ring is finely adjusted. .
[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0066] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.
[0067] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable storage medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable storage medium could be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.
[0068] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.
[0069] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.
[0070] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.
[0071] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.
[0072] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A method for generating acoustic waves at the optimal matching frequency for target soil, characterized in that, An adaptive ring-shaped center-excitation sound source module is applied to the adaptive ring-shaped center-excitation sound source module, which includes a control unit, an external sensor, a vibration excitation unit, and a vibration isolation protection unit. The method for generating the acoustic wave with the optimal matching frequency for the target soil includes: The control unit acquires environmental baseline parameters of the target soil collected by the external sensors; The control unit generates impedance matching instructions and acoustic wave design instructions based on the environmental reference parameters. The control unit adjusts the vibration isolation protection unit to the target state according to the impedance matching command; The control unit controls the vibration excitation unit to generate target sound waves according to the sound wave design instructions, so as to transmit the target sound waves to the target soil through the vibration isolation protection unit in the target state.
2. The method for generating acoustic waves with the optimal matching frequency for the target soil according to claim 1, characterized in that, The environmental baseline parameters include soil temperature, initial moisture content, and burial pressure. The generation of impedance matching instructions and acoustic wave design instructions based on the environmental reference parameters specifically includes: The average acoustic impedance is calculated based on the soil temperature, the initial moisture content, and the burial depth pressure. Impedance matching instructions and acoustic wave design instructions are generated based on the average acoustic impedance.
3. The method for generating sound waves at the optimal matching frequency for the target soil according to claim 2, characterized in that, The calculation of the average acoustic impedance based on the soil temperature, the initial moisture content, and the burial depth pressure specifically includes: The soil temperature, the initial moisture content, and the burial depth pressure are input into the soil acoustic model, and the soil density and soil sound velocity are output. The average acoustic impedance of the target soil is calculated based on the soil density and the soil sound velocity.
4. The method for generating sound waves with the optimal matching frequency for the target soil according to claim 2, characterized in that, The generation of impedance matching instructions and acoustic wave design instructions based on the average acoustic impedance specifically includes: The target stiffness required for acoustic impedance matching of the zoom coupling cavity is calculated based on the average acoustic impedance, the target current applied to the global ring electromagnetic coil is obtained based on the target stiffness, and an impedance matching command is generated based on the target current. The target radial distance of the target soil is determined based on the average acoustic impedance, and the target excitation parameters of the PZT excitation ring are obtained based on the target radial distance. The acoustic wave design command is then generated based on the target excitation parameters.
5. The method for generating acoustic waves with the optimal matching frequency for the target soil according to claim 4, characterized in that, The step of controlling the vibration excitation unit to generate the target sound wave according to the sound wave design command further includes: The real-time vibration data of the target soil collected by the external sensor is acquired, and the real-time vibration data is compared with the target excitation parameters to obtain the deviation value characteristics; The determination result is made based on the deviation value characteristics, and the average acoustic impedance generation impedance matching command or acoustic wave design command is corrected based on the determination result.
6. An adaptive ring-shaped central excitation sound source module, used to implement the method according to any one of claims 1 to 5, characterized in that, The adaptive ring-shaped center excitation sound source module includes a control unit, external sensors, a vibration excitation unit, and a vibration isolation protection unit. The control unit is connected to the vibration excitation unit, the vibration isolation protection unit and the external sensor respectively. The vibration isolation protection unit is connected to the outside of the vibration excitation unit, and the outer wall of the vibration isolation protection unit is used to contact the soil to be tested. The external sensor is used to collect environmental baseline parameters and real-time vibration feedback of the target soil. The control unit is used to generate impedance matching instructions and acoustic design instructions based on the environmental reference parameters, correct the impedance matching instructions and acoustic design instructions based on the real-time vibration feedback, and send the impedance matching instructions to the vibration isolation protection unit and the acoustic design instructions to the vibration excitation unit. The vibration isolation protection unit is used to adjust to the target state according to the impedance matching command; The vibration excitation unit is used to generate a target sound wave according to the sound wave design instructions, so as to transmit the target sound wave to the target soil through the vibration isolation protection unit in the target state.
7. The adaptive ring-shaped center-excited sound source module according to claim 6, characterized in that, The control unit is the main control drive circuit, the external sensors include an environmental sensor array and a vibration feedback sensor, the vibration isolation protection unit includes an acoustic impedance matching zoom coupling cavity and a global ring electromagnetic inductance, and the vibration excitation unit includes a PZT excitation ring and a harmonic generator. The environmental sensor array, the vibration feedback sensor, the acoustic impedance matching zoom coupling cavity, and the global annular electromagnetic inductance are respectively connected to the main control drive circuit. The global annular electromagnetic inductance is arranged around the acoustic impedance matching zoom coupling cavity, and the vibration feedback sensor is arranged inside the PZT excitation ring.
8. The adaptive ring-shaped center-excited sound source module according to claim 7, characterized in that, The adaptive ring-shaped center excitation sound source module also includes a power amplifier, which is connected to the main control drive circuit and is correspondingly set with the PZT excitation ring; the PZT excitation ring includes multiple sets of ring-arranged curved PZT sheets.
9. The adaptive ring-shaped center-excited sound source module according to claim 8, characterized in that, The adaptive ring-shaped central excitation sound source module also includes a housing, on which the central part of the vibration excitation unit is mounted. The housing is in the shape of an inverted hat.
10. The adaptive ring-shaped central excitation sound source module according to claim 9, characterized in that, The environmental sensor array includes multiple burial depth pressure sensors, soil moisture sensors, and soil temperature sensors. The multiple burial depth pressure sensors are all located on the top of the encapsulation housing, while the soil moisture sensors and the soil temperature sensors are located outside the acoustic impedance matching zoom coupling cavity.