Sand production monitoring device based on cantilever beam structure and acousto-optic effect

Abstract

The invention discloses a sand production monitoring device based on a cantilever beam structure and an acousto-optic effect, and relates to the technical field of vibration monitoring. Comprising a vibration transducer which is of a cantilever beam structure and is used for sensing a vibration signal generated by movement of sand grains in a pipeline; the PDMS conducting layer is directly generated on the vibration transducer; the optical waveguide structure is formed on the PDMS conducting layer; the light source emitter is used for emitting a detection light signal to the optical waveguide structure; a vibration signal is transmitted to the optical waveguide structure through the PDMS conducting layer, an acousto-optic effect is caused, and a modulated optical signal is obtained; the optical detector is used for converting the modulated optical signal into an original electric signal; and the processing unit is used for processing the original electric signal and outputting an electric signal representing the sand production state of the pipeline. According to the invention, vibration can be induced through the cantilever beam structure and optical modulation is carried out by using the acousto-optic effect, so that high-sensitivity and high-stability detection of weak vibration signals of sand movement in the pipeline is realized.

Description

Technical Field

[0001] This invention relates to the field of vibration monitoring technology, and in particular to a sand discharge monitoring device based on a cantilever beam structure and acoustic-optical effects. Background Technology

[0002] With the rapid development of technology, acoustic detection technology has been widely applied in industrial production and pipeline health diagnosis, especially in the monitoring of oil and gas pipelines. Acoustic technology enables precise diagnosis of the internal operating conditions of pipelines, meeting the ever-increasing monitoring needs. Traditional sand monitoring devices employ various technical solutions, including mechanical (such as pendulum or baffle type), magnetic induction, acoustic or vibration, pressure wave detection, ultrasonic Doppler, and radio frequency identification (RFID) methods. These technologies each have their advantages in different scenarios, providing diverse monitoring methods for oil and gas extraction. Among them, acoustic detection dominates the field of ball bearing indicator measurement due to its high sensitivity and accuracy. This method captures the subtle effects of external acoustic signals on the internal operation of the pipeline and converts them into quantifiable vibration signal data. It can keenly sense the weak vibrations caused by sand particle movement, providing crucial support for pipeline operation monitoring.

[0003] However, existing acoustic wave detection technologies have revealed significant shortcomings in practical applications. First, the microphone, upon which this technology relies, is a relatively fragile acoustic signal acquisition element. When measuring external micro-vibrations, high-frequency sound signals are easily affected by environmental interference, leading to signal distortion. To ensure data accuracy, the microphone's packaging process requires extremely stringent specifications, including sound insulation, dustproofing, moisture resistance, and electromagnetic shielding. Any packaging defects can cause measurement errors. Second, the integration of cantilever piezoelectric ceramics with the transducer packaging structure presents technical challenges in sensor design. Piezoelectric ceramics require high processing precision and material properties, while the transducer structure needs to balance signal conversion efficiency and stability. The integration of these two technologies is fraught with difficulties, easily leading to stress concentration or signal loss, thus increasing R&D and production costs. Furthermore, traditional acoustic sensors often use adhesive bonding between the piezoelectric ceramic and the transducer structure. While this process is simple, in the complex environments of oil and gas extraction, such as high temperature, high pressure, or strong corrosion, the adhesive is prone to aging and failure, resulting in decreased structural stability and unreliable signal conversion and transmission, failing to meet stringent detection requirements. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a sand discharge monitoring device based on a cantilever beam structure and acoustic-optical effect. This device can sense vibrations through the cantilever beam structure and utilize the acoustic-optical effect for optical modulation, achieving highly sensitive and stable detection of weak vibration signals from sand particles moving within the pipeline.

[0005] To achieve the above objectives, the present invention provides a sand discharge monitoring device based on a cantilever beam structure and acoustic-optical effects, comprising: The vibration transducer, with a cantilever beam structure, is used to sense the vibration signals generated by the movement of sand particles inside the pipe. The PDMS conductive layer is directly formed on the vibration transducer; An optical waveguide structure is formed on the PDMS conductive layer; A light source emitter is used to emit a probe light signal to the optical waveguide structure; the vibration transducer deforms after sensing the vibration signal and transmits it to the optical waveguide structure through the PDMS conductive layer, causing an acousto-optic effect to modulate the probe light signal incident on the optical waveguide structure to obtain a modulated light signal; A photodetector is disposed on the transmission optical path of the modulated optical signal to receive the modulated optical signal and convert the modulated optical signal into a raw electrical signal; The processing unit, connected to the photodetector, is used to process the raw electrical signal and output an electrical signal characterizing the sand discharge status of the pipeline.

[0006] Optionally, the vibration transducer is a cantilever beam sapphire piezoelectric ceramic sheet.

[0007] Optionally, the optical waveguide structure includes a silicon dioxide layer formed on the PDMS conductive layer and a phase-shift waveguide grating etched on the silicon dioxide layer.

[0008] Optionally, the silicon dioxide layer is a silicon dioxide material doped with rare earth elements.

[0009] Optionally, the PDMS conductive layer is directly formed on the vibration transducer using MEMS technology.

[0010] Optionally, the vibration transducer, PDMS conductive layer, and optical waveguide structure constitute an integrated structure in which they are sequentially stacked.

[0011] Optionally, the device further includes: A light reflection structure is provided corresponding to the optical waveguide structure and the photodetector, and is used to reflect the modulated light signal from the optical waveguide structure to the photodetector.

[0012] Optionally, the photodetector is a CCD image sensor or a CMOS image sensor.

[0013] Optionally, the processing unit includes: An amplifier, connected to the photodetector, is used to receive and amplify the raw electrical signal from the photodetector; An analog-to-digital converter, with its input connected to the output of the amplifier, is used to convert the amplified original electrical signal into a digital signal. A digital signal processor, connected to the analog-to-digital converter, is used to process the digital signal and output the electrical signal characterizing the sand discharge status of the pipeline.

[0014] Optionally, the device further includes: A sealed housing is used to encapsulate the vibration transducer, PDMS conductive layer, and optical waveguide structure.

[0015] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: The sand discharge monitoring device based on a cantilever beam structure and acousto-optic effect provided by this invention directly senses the vibration signal generated by the movement of sand particles inside the pipeline through a cantilever beam vibration transducer. Combined with a PDMS conductive layer directly generated on the transducer, it achieves efficient and low-loss transmission of the vibration signal. This integrated structure avoids the interface instability problems caused by traditional bonding processes, significantly improving the structural stability and durability of the sensor in harsh environments such as high temperature, high pressure, and strong corrosion. The device utilizes an optical waveguide structure formed on the PDMS conductive layer to convert mechanical vibration into optical signal modulation through an acousto-optic effect, thereby replacing the microphone element in traditional acoustic detection.

[0016] When a vibration signal is detected, the detection light signal provided by the light source emitter is modulated in the optical waveguide structure, forming a modulated light signal carrying vibration information. This modulated light signal is received by the photodetector and converted into a raw electrical signal, which is then analyzed and processed by the processing unit to output an electrical signal that directly characterizes the sand discharge status of the pipeline. This "mechanical vibration-acoustic-optical modulation-photoelectric conversion" detection mechanism transforms the signal carrier from an easily interfered electrical signal into an optical signal, thereby effectively overcoming the defects of high-frequency acoustic signals being susceptible to electromagnetic interference and environmental noise, reducing the dependence on complex sensor packaging processes, and improving the overall reliability and measurement accuracy of signal acquisition. Attached Figure Description

[0017] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0018] Figure 1 This is a schematic diagram of the sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect, as shown in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the working principle of a sand discharge monitoring device based on a cantilever beam structure and acoustic-optical effect, as shown in an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the hardware structure of a sand discharge monitoring device based on a cantilever beam structure and acoustic-optical effects.

[0021] A sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect includes: Vibration transducer 1 is a cantilever beam structure used to sense vibration signals generated by the movement of sand particles inside the pipe; PDMS conductive layer 2 is directly generated on the vibration transducer; Optical waveguide structure 3 is formed on the PDMS conductive layer; The light source emitter 4 is used to emit a probe light signal to the optical waveguide structure; the vibration transducer deforms after sensing the vibration signal and transmits it to the optical waveguide structure through the PDMS conductive layer, causing an acousto-optic effect to modulate the probe light signal incident on the optical waveguide structure to obtain a modulated light signal; A photodetector 5 is disposed on the transmission optical path of the modulated optical signal, for receiving the modulated optical signal and converting the modulated optical signal into a raw electrical signal; Processing unit 6, connected to the photodetector, is used to process the original electrical signal and output an electrical signal characterizing the sand discharge status of the pipeline.

[0022] This monitoring device aims to address the problems of traditional acoustic detection technology, such as susceptibility to environmental interference, poor sensor integration, and insufficient stability under harsh conditions like high temperature, high pressure, and strong corrosion. By combining a cantilever beam vibration sensing structure with acoustic-optical modulation technology, this device can achieve high-precision, interference-resistant detection of weak vibration signals generated by sand movement within pipelines, making it particularly suitable for real-time monitoring of sand discharge status in oil and gas pipelines.

[0023] During operation, the vibrations generated by the movement of sand particles inside the pipeline are first sensed by the cantilever beam vibration transducer 1 and converted into mechanical vibration signals. These signals are then efficiently and losslessly transmitted to the integrated optical waveguide structure 3 via a PDMS (polydimethylsiloxane) conductive layer. Inside the optical waveguide structure 3, the vibration signal modulates the detection light through an acousto-optic effect, forming a modulated optical signal carrying vibration information. This modulated optical signal is received by the photodetector 5 and converted into a raw electrical signal. The processing unit 6 processes the raw electrical signal through a series of steps and outputs a quantitative indicator that can be used to assess the sand discharge status of the pipeline. This "vibration-acousto-optic-photoelectric" conversion and detection mechanism not only improves the sensitivity and accuracy of detecting weak signals but also significantly enhances the device's anti-interference capability and long-term operational stability in complex industrial environments through its all-optical-path and integrated structural design.

[0024] Vibration transducer 1, as the core sensing component of the device, adopts a cantilever beam structure and is specifically designed to capture vibration signals caused by the movement of sand particles inside the pipe. It is directly exposed inside the pipe or contacts the pipe wall through a mechanical coupling structure to sense vibration signals generated by sand particles impacting or rubbing against the pipe wall. This cantilever beam structure has high mechanical sensitivity, capable of converting weak mechanical vibrations into corresponding deformation or stress changes. By adopting the cantilever beam form, stress distribution is optimized, avoiding the stress concentration and interface signal loss problems commonly found in traditional adhesive bonding, thus laying the foundation for high-fidelity signal transmission.

[0025] For example, the vibration transducer 1 is a cantilever beam sapphire piezoelectric ceramic sheet. The vibration transducer 1, made of sapphire piezoelectric ceramic material, has both high mechanical strength and excellent piezoelectric sensitivity, and can effectively convert weak mechanical vibrations into electrical or mechanical responses.

[0026] The PDMS conductive layer 2 is directly formed on top of the vibration transducer 1, serving as a highly efficient medium for transmitting vibration signals. This layer is integrally molded on the transducer surface using microelectromechanical systems (MEMS) technology, forming a soft and elastic polymer interlayer that ensures a tight bond with the underlying transducer. PDMS material possesses excellent acoustic conductivity and impedance matching capabilities, enabling low-loss and high-fidelity transmission of the mechanical vibration signals captured by the vibration transducer 1 to the upper optical structure. This direct-formation process avoids the use of organic adhesives, thus overcoming performance degradation and structural failure issues caused by adhesive aging in high-temperature, high-pressure, or corrosive environments, enhancing the overall structural reliability and durability.

[0027] An optical waveguide structure 3 is formed on the PDMS conductive layer 2 to achieve acousto-optic conversion. Exemplarily, the optical waveguide structure 3 includes a silicon dioxide layer formed on the PDMS conductive layer 2 and a phase-shifting waveguide grating etched on the silicon dioxide layer. The silicon dioxide layer may be a rare-earth-doped silicon dioxide material.

[0028] The silica layer, with its high transparency and low optical loss, ensures efficient transmission of the probe light; the phase-shifted waveguide grating is used for precise modulation of the light wave. When the mechanical vibration signal carrying the vibration information of sand grains is transmitted to the optical waveguide structure 3 through the PDMS conductive layer 2, it causes periodic perturbations in the refractive index of the waveguide material, thereby generating an acousto-optic effect. This effect modulates the probe light propagating within the waveguide, changing its phase or intensity, ultimately generating a modulated optical signal carrying vibration characteristic information. By directly converting mechanical vibration into changes in optical signals, interference from the electromagnetic environment is effectively avoided.

[0029] The light source emitter 4 generates and outputs a stable probe light signal. This probe light signal is guided and injected into a specific area of ​​the optical waveguide structure 3 through precise optical coupling (e.g., via optical fiber or direct spatial optical path alignment) to ensure efficient entry into the waveguide and transmission along the designed path. The photosensitive surface of the photodetector 5 is positioned corresponding to the light emission direction of the optical waveguide structure 3 to receive the modulated light signal emitted from the optical waveguide structure 3 and modulated by the pipe vibration signal. As the core photoelectric conversion device, the photodetector 5 accurately converts the received modulated light signal carrying vibration information (specifically manifested as a linear change in light intensity or phase) into a corresponding original electrical signal, such as a voltage or current signal, for subsequent circuit processing.

[0030] In practical implementation, in order to accurately capture subtle changes in the light signal, the photodetector 5 can use high-resolution, high-sensitivity photoelectric detection elements such as CCD (charge-coupled device) image sensors or CMOS (complementary metal-oxide-semiconductor) image sensors. These elements are capable of finely sampling the light intensity distribution in space or time.

[0031] The processing unit 6 is directly connected to the electrical signal output terminal of the photodetector 5, forming a pathway for subsequent signal conditioning and analysis. It receives the raw electrical signal from the photodetector 5 and, through signal processing, ultimately generates an electrical signal to characterize the sand discharge status of the pipeline.

[0032] For example, processing unit 6 includes: An amplifier, connected to the photodetector 5, is used to receive and amplify the raw electrical signal from the photodetector 5; An analog-to-digital converter (ADC) has its input connected to the output of an amplifier and is used to convert the amplified original electrical signal into a digital signal. A digital signal processor, connected to an analog-to-digital converter, is used to process digital signals and output electrical signals that characterize the sand discharge status of the pipeline.

[0033] In the application, processing unit 6 first receives the raw electrical signal from photodetector 5, which is typically weak and may contain noise. Therefore, the raw electrical signal undergoes initial conditioning, and is amplified appropriately by an amplifier to improve the signal-to-noise ratio and the dynamic range for subsequent processing. Subsequently, the pre-amplified analog signal is converted into a digital signal by an analog-to-digital converter to facilitate complex digital calculations and feature extraction.

[0034] The digital signal processor (DSP) is connected to the analog-to-digital converter (ADC) and serves as the final stage of information processing, performing algorithmic analysis and processing on the input digital signals. This processor can run various digital signal processing algorithms, such as digital filtering to further suppress power frequency interference or specific environmental noise, performing fast Fourier transforms to analyze the spectral components of vibration signals, or extracting features directly related to sand particle movement from the digital signal stream in real time through methods such as threshold comparison, envelope detection, and feature pattern recognition. After processing, the DSP ultimately outputs one or more clearly defined electrical signals characterizing the sand discharge status of the pipeline. This output signal can be a switching signal, analog signal, or digital communication protocol format, which can directly drive alarm devices, upload data to the monitoring center, or be used for historical data recording and analysis, achieving precise sensing of the pipeline's operating status.

[0035] Furthermore, the vibration transducer 1, the PDMS conductive layer 2, and the optical waveguide structure 3 constitute an integrated structure that is sequentially stacked. They are not separate components assembled independently, but are integrated into a compact and robust integrated functional unit through precise micro-nano manufacturing processes in a sequentially stacked manner.

[0036] This high degree of physical integration significantly reduces the device's size, resulting in a simple, robust structure that is easy to install, making it particularly suitable for deployment in space-constrained pipeline environments. Furthermore, the integrated structure eliminates the tolerance, loosening, and sealing challenges associated with assembling multiple independent components, leading to higher overall mechanical strength and better adaptability to the mechanical vibrations and pressure fluctuations commonly encountered in oil and gas pipeline monitoring. In addition, the interlayer bonding, achieved through a generative process, results in excellent interface characteristics, significantly reducing interface reflection, scattering, and energy loss during vibration signal transmission, ensuring high fidelity and efficiency in the conversion from mechanical vibration to optically modulated signals.

[0037] In one embodiment, the above-mentioned apparatus further includes: The light reflection structure 7 is configured in correspondence with the optical waveguide structure and the photodetector, and is used to reflect the modulated light signal from the optical waveguide structure to the photodetector.

[0038] In this application, the introduction of the light reflection structure 7 allows for the construction of a compact reflective optical path, making the overall device layout more flexible and facilitating installation and integration in space-constrained pipeline monitoring environments. Specifically, the light reflection structure 7 is positioned on the outgoing path of the modulated light signal generated by the optical waveguide structure. When the modulated light signal exits the optical waveguide structure, it directly strikes the reflecting surface of the light reflection structure 7. To efficiently reflect the modulated light signal, a titanium dioxide coating is applied to the reflecting surface of this structure. This titanium dioxide coating is formed on the reflective surface substrate (such as glass, silicon wafer, or metal mirror mount) using physical vapor deposition or similar thin-film processes, forming a uniform and dense interference film. Titanium dioxide has a higher refractive index than common optical substrate materials, enabling highly efficient reflection of the specific operating wavelength of the probe light signal. This significantly reduces energy loss during transmission, ensuring that the vast majority of the modulated light signal is reflected to the photodetector.

[0039] The light reflection structure 7 provides flexibility in optical path design, freeing the layout of optical components from the constraints of straight optical paths, which is beneficial for miniaturization and irregular packaging of the device. Through the carefully designed reflective surface, the coupling efficiency of the optical signal to the photodetector 5 can be improved, and the light spot may be converged to a certain extent, which helps to improve the signal strength of the modulated optical signal incident on the photodetector 5. The enhancement of signal strength can improve the signal-to-noise ratio of the photoelectric conversion channel of the entire monitoring device, thereby helping to capture and identify subtle changes in pipeline vibration.

[0040] In one embodiment, the above-mentioned apparatus further includes: The sealed housing 8 is used to encapsulate the vibration transducer 1, the PDMS conductive layer 2, and the optical waveguide structure 3.

[0041] The sealed housing 8 is an outer casing with good mechanical strength and sealing performance. Its internal cavity is used to house and encapsulate the integrated sensing unit consisting of the aforementioned vibration transducer 1, PDMS conductive layer 2, and optical waveguide structure 3. This sealed housing 8 provides a robust physical barrier, preventing external mechanical impacts, dust, moisture, or corrosive media from directly contacting and damaging the internal precision micro / nano structures and optical interfaces. It also isolates the intrusion of flammable and explosive gases, high-pressure fluids, or humid air commonly found in oil and gas pipeline environments, ensuring the safety of internal components in terms of dust and moisture protection. Furthermore, the sealed housing 8, made of conductive materials such as metal, also serves as electromagnetic shielding, effectively blocking interference from external electric and magnetic fields, providing a clean electrical environment for internal photoelectric conversion and signal processing.

[0042] Furthermore, the sealed housing 8 may also be provided with a vibration transmission structure, which is mechanically coupled to the vibration transducer 1.

[0043] The vibration transmission structure on the sealed housing 8 can be designed as a rigid or flexible mechanical element extending from the outer surface of the housing to the interior, achieving direct mechanical contact with the internal vibration transducer 1, thus realizing mechanical coupling. One end of this vibration transmission structure is exposed outside the housing and can be tightly fixed to the outer wall of the pipe being tested or to a dedicated mounting base by means of threaded connection, welding, or clamps, thereby directly sensing the vibration of the pipe caused by the movement of sand particles. The other end penetrates the housing and is firmly connected to the vibration transducer 1 (such as the fixed end or sensitive surface of a cantilever beam) encapsulated inside the housing. In this way, the vibration energy of the pipe wall is directly transmitted to the vibration transducer 1 through the bridge of the vibration transmission structure, driving it to deform or vibrate.

[0044] The following describes the fabrication method of the sand discharge monitoring device based on the cantilever beam structure and acousto-optic effect. In application, by employing a process combining sequential integration and micro-nano manufacturing, the vibration transducer 1, PDMS conductive layer 2, and optical waveguide structure 3 are combined into an integrated, highly stable sensing core, thereby overcoming the problems of interface instability, signal attenuation, and poor environmental adaptability caused by the bonding process in traditional acoustic sensors.

[0045] The fabrication process begins with the vibration transducer 1, which serves as the mechanical sensing substrate. This transducer employs a cantilever beam structure design and can be made from high-performance materials such as sapphire piezoelectric ceramics, exhibiting excellent mechanical sensitivity and frequency response characteristics. On the cleaned and prepared transducer surface, PDMS material is directly generated and cured using microelectromechanical systems (MEMS) technology, forming a uniform, dense, and seamlessly integrated flexible conductive layer. This direct generation process avoids the introduction of third-party adhesives, thus completely eliminating the risk of structural delamination and signal transmission degradation caused by adhesive aging and failure in high-temperature, high-pressure, or corrosive environments. This ensures efficient and low-loss transmission of vibration signals from the transducer to the conductive layer.

[0046] After the PDMS conductive layer 2 is cured and provides a stable substrate, the optical waveguide structure 3 is constructed on it. First, a high-quality silicon dioxide layer is deposited on the surface of the PDMS layer using chemical vapor deposition or a similar thin film growth technique to form an optical light guide layer. Subsequently, precise photolithography and etching processes are used to define and etch the designed micro / nano optical structures, such as phase-shift waveguide gratings, within the silicon dioxide layer.

[0047] This achieves precise integration of the optical functional unit with the underlying PDMS conductive layer 2, making the entire "vibration transducer 1 - PDMS conductive layer 2 - optical waveguide structure 3" a sequentially stacked and robustly integrated composite. This integrated structure ensures that when the vibration signal is transmitted through the PDMS layer, it can effectively induce refractive index modulation in the waveguide region, thereby achieving highly sensitive acousto-optic conversion of the optical signal.

[0048] After the core sensing unit is fabricated, the optical and electrical systems are integrated. The light source emitter 4 is precisely aligned and fixedly coupled to the optical waveguide structure 3 via optical fiber or spatial optical path to emit stable detection light. At the same time, the photodetector 5 is also correspondingly set to the optical waveguide structure 3 to receive the modulated optical signal.

[0049] Furthermore, the aforementioned integrated sensing core, along with its coupled optical interface, can be assembled and sealed within a dedicated protective housing. During the packaging process, it is essential to ensure reliable and robust mechanical coupling between the pre-installed vibration transmission structure on the housing and the vibration transducer 1 within the sensing core. This establishes an efficient vibration transmission path from the external conduit to the internal sensitive unit, while simultaneously guaranteeing the overall airtightness and environmental protection level of the housing.

[0050] This manufacturing method simplifies and strengthens the sensor structure by directly generating and integrating key functional layers sequentially. It abandons the traditional multi-component gluing assembly method, not only simplifying the process and improving production consistency, but also significantly enhancing the long-term operational stability and reliability of the monitoring device in complex industrial environments.

[0051] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect, characterized in that, include: The vibration transducer, with a cantilever beam structure, is used to sense the vibration signals generated by the movement of sand particles inside the pipe. The PDMS conductive layer is directly formed on the vibration transducer; An optical waveguide structure is formed on the PDMS conductive layer; A light source emitter is used to emit a probe light signal to the optical waveguide structure; the vibration transducer deforms after sensing the vibration signal and transmits it to the optical waveguide structure through the PDMS conductive layer, causing an acousto-optic effect to modulate the probe light signal incident on the optical waveguide structure to obtain a modulated light signal; A photodetector is disposed on the transmission optical path of the modulated optical signal to receive the modulated optical signal and convert the modulated optical signal into a raw electrical signal; The processing unit, connected to the photodetector, is used to process the raw electrical signal and output an electrical signal characterizing the sand discharge status of the pipeline.

2. The sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect according to claim 1, characterized in that, The vibration transducer is a cantilever beam sapphire piezoelectric ceramic sheet.

3. The sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect according to claim 1, characterized in that, The optical waveguide structure includes a silicon dioxide layer formed on the PDMS conductive layer and a phase-shift waveguide grating etched on the silicon dioxide layer.

4. The sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect according to claim 3, characterized in that, The silicon dioxide layer is a silicon dioxide material doped with rare earth elements.

5. The sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect according to claim 1, characterized in that, The PDMS conductive layer is directly formed on the vibration transducer using MEMS technology.

6. The sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect according to claim 1, characterized in that, The vibration transducer, PDMS conductive layer, and optical waveguide structure constitute an integrated structure that is sequentially stacked.

7. The sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect according to claim 1, characterized in that, The device further includes: A light reflection structure is provided corresponding to the optical waveguide structure and the photodetector, and is used to reflect the modulated light signal from the optical waveguide structure to the photodetector.

8. A sand discharge monitoring device based on cantilever beam structure and acoustic-optical effect according to claim 1, characterized in that, The photodetector is a CCD image sensor or a CMOS image sensor.

9. A sand discharge monitoring device based on a cantilever beam structure and acoustic-optical effect according to claim 7, characterized in that, The processing unit includes: An amplifier, connected to the photodetector, is used to receive and amplify the raw electrical signal from the photodetector; An analog-to-digital converter, with its input connected to the output of the amplifier, is used to convert the amplified original electrical signal into a digital signal. A digital signal processor, connected to the analog-to-digital converter, is used to process the digital signal and output the electrical signal characterizing the sand discharge status of the pipeline.

10. A sand discharge monitoring device based on a cantilever beam structure and acoustic-optical effect according to claim 1, characterized in that, The device further includes: A sealed housing is used to encapsulate the vibration transducer, PDMS conductive layer, and optical waveguide structure.

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