Electrostatic induction pendulum for earthquake monitoring and early warning based on electrostatic induction

Abstract

The utility model discloses an electrostatic induction pendulum for earthquake monitoring and early warning based on electrostatic induction. The device comprises a pendulum and an electrostatic induction sensor, and tiny potential changes can be detected in the swinging process. As a core component, the electrostatic induction sensor consists of the following key parts: a weight module, a connecting layer I, an electrode layer, a connecting layer II and an electrostatic interaction layer. Wherein the weight module provides necessary mass so as to ensure the dynamic characteristics of the pendulum; the first connecting layer is used for fixing the connection between the weight module and the electrode layer; the electrode layer is responsible for detecting electrostatic induction signals generated by pendulum motion and converting the signals into measurable potential change; the second connecting layer is used for fixing the electrode layer and the electrostatic interaction layer; the material of the electrostatic interaction layer carries charges, and the electrostatic induction signal of the electrode layer is enhanced in the earthquake monitoring and early warning process. Through the design, the device can realize high-sensitivity monitoring of earthquake precursor, and can capture fine ground movement caused by earthquake waves. In combination with a data acquisition system and a machine learning algorithm, the device can analyze the signals in real time and automatically send early warning information to related departments and individuals when an abnormal vibration mode is detected, so that precious time is won for taking preventive measures.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of earthquake warning and flexible electronic sensors, in particular to a static induction type pendulum for earthquake monitoring and warning based on static induction. BACKGROUND

[0002] The invention patent "Earthquake monitoring device and system" (Application number: CN202410584297.4, Application publication number: CN118483734A) applied by China State Railway Group Co., Ltd. provides an earthquake monitoring device and system. The device includes a solar power supply unit, a data acquisition unit, and a communication unit. The solar power supply unit is electrically connected to the data acquisition unit and the communication unit, respectively, and is used to supply power to the data acquisition unit and the communication unit. The data acquisition unit includes a MEMS sensor and a positioning module. The MEMS sensor is used to collect earthquake information, and the positioning module is used to obtain the position information of the earthquake monitoring device. The communication unit is electrically connected to the data acquisition unit, and is used to wirelessly transmit the earthquake information and the position information to a cloud server. The device has high monitoring accuracy and does not need to replace the battery frequently. However, the energy supply of the device depends on solar energy, and in areas with insufficient light, the energy supply may be unstable, so it is greatly affected by the environment. The invention patent "Self-organizing earthquake monitoring and early warning method based on emergency information release system" (Application number: CN202311147435.4, Application publication number: CN117152917A) applied by China Railway Eryuan Engineering Group Co., Ltd. and Taiji Computer Co., Ltd. discloses a self-organizing earthquake monitoring and early warning method based on an emergency information release system. The invention arranges multiple monitoring terminals in the monitored earthquake area and selects a master monitoring terminal. The master monitoring terminal is determined by election, and the remaining slave monitoring terminals combine the earthquake wave data detected by the master monitoring terminal to obtain intermediate results. The intermediate results are combined with the earthquake wave data detected by the monitoring terminals of the upper level monitored earthquake area to obtain final result data and transmitted to the emergency information release system to determine whether to trigger an earthquake warning. Although the invention reduces the communication link between the seismic network center and the emergency information release system, it can further shorten the warning time. It solves the problem that the existing earthquake monitoring method cannot issue a warning in a short time due to the long distance between seismic stations. However, in practical applications, it relies on the distribution and cooperative work of multiple monitoring terminals, which requires a large infrastructure investment; and the determination of the epicenter position may be affected by the distribution of monitoring terminals and data quality. To reduce the dependence on infrastructure and improve data quality and the accuracy of epicenter positioning, the invention patent "Real-time co-seismic displacement velocity solving method and system based on Beidou PPP-B2b service" (Application number: CN202310699165.1, Application publication number: CN116973974A) applied by China University of Petroleum (East China) discloses a real-time co-seismic displacement velocity solving method based on Beidou PPP-B2b service.This method uses the orbit, clock error and code bias correction numbers broadcast by the Beidou PPP-B2b service, combined with GNSS observation data, to provide real-time displacement, velocity and acceleration calculations for earthquake monitoring stations without network communication, reducing the dependence on widely distributed monitoring terminals. Through precise ephemeris calculation and error correction, the quality of the observation data and the accuracy of the epicenter positioning are improved, providing a stable and reliable real-time displacement, velocity and acceleration calculation method for GNSS earthquake monitoring stations in the near field of strong earthquakes without network communication. Although its method provides observation data for earthquake monitoring and early warning research, there are still some problems in practical application. Its invention requires specific receivers and processing equipment, increasing the deployment cost and maintenance difficulty of the system, and it relies on the Beidou PPP-B2b service, which means that if the service fails or is unavailable, it may affect the operation of the entire system.

[0003] Existing earthquake monitoring methods, although they have made some progress in earthquake activity detection and early warning, still face many challenges and limitations. First of all, the cost is a significant obstacle. The deployment of existing earthquake monitoring systems requires a large number of hardware devices, and the purchase, installation and maintenance of these devices require huge investments. And the operation of the system also requires continuous energy supply and technical support, which will also bring additional operating costs. High costs may limit the popularization of earthquake monitoring systems, especially in economically underdeveloped areas, which may be the areas most in need of earthquake warning capabilities; secondly, the distance between seismic stations may cause information transmission delay, affecting the timeliness of early warning; thirdly, existing monitoring technology may be disturbed by environmental noise, affecting the accuracy and reliability of the data; finally, the complexity of geological conditions also affects the propagation of seismic waves, making it more difficult to interpret monitoring data. In view of these challenges, it is particularly urgent to develop new earthquake monitoring technology. SUMMARY

[0004] In view of the high cost, incomplete coverage and deployment difficulties in remote areas of the above-mentioned technology, the present application proposes a static electric induction earthquake monitoring and early warning device - static electric induction pendulum.

[0005] The technical solution adopted by the present application to solve its technical problems: a static electric induction pendulum for earthquake monitoring and early warning based on static electric induction, comprising a conductive pendulum line and a pendulum bob, one end of the conductive pendulum line is fixedly connected with the pendulum bob, wherein the pendulum bob is cylindrical, the center of the pendulum bob is a weight module (1), the outside of the weight module (1) is sequentially connected with a connection layer one (2), an electrode layer (3), a connection layer two (4), and a static electric interaction layer (5); a part of the conductive pendulum line is connected with the electrode layer (3) when the conductive pendulum line is fixedly connected with the pendulum bob, and the conductive pendulum line is long enough and at least does not affect the movement of the pendulum.

[0006] Preferably, the cylindrical model of the weight module (1) is made by 3D printing technology, and its material is polylactic acid.

[0007] Preferably, the effective projection area of the weight module (1) is between 10-100 cm 2 , and the mass is between 10-150 g.

[0008] Preferably, the connection layer one (2) and the connection layer two (4) are VHB tapes, which firmly bond the weight module (1) and the electrode layer (3), and the electrode layer (3) and the electrostatic interaction layer (5), respectively.

[0009] Preferably, the electrode layer (3) is made of copper, which is used to detect and convert the electrostatic induction signal. When external vibration such as seismic wave causes the pendulum to move, the relative position change between the electrode layer (3) and the spatially distributed electric charge occurs, which leads to the change of the electric field distribution, thereby generating a potential difference on the electrode layer. This potential difference change is detected by the electrode layer and converted into an electrical signal, and then these signals are transmitted through the wire connected with the electrode layer (3) to the Keithley 6517B electrometer and the DMM6500 desktop digital touch screen multimeter for further processing and analysis.

[0010] Preferably, the electrostatic interaction layer (5) is made of thermoplastic polyurethane by electrospinning technology. As one of the key materials, thermoplastic polyurethane itself carries static charge, which can effectively enhance the electrostatic induction signal of the electrode layer (3) in the process of earthquake monitoring, and provide reliable signal for subsequent earthquake warning.

[0011] A seismic monitoring and warning device, comprising the electrostatic induction pendulum of any one of the preceding claims, further comprising a data acquisition module and a decision support system based on electrostatic induction for seismic monitoring and warning. This decision support system is jointly driven by six machine learning algorithms, including K-Nearest Neighbors (KNN), Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF), Extreme Gradient Boosting (XGB), and Multi-layer Perceptron (MPL). These algorithms work together to realize real-time acquisition, analysis and processing of the potential difference signal generated in the pendulum movement.

[0012] Compared with the prior art, the present application has the following beneficial effects.

[0013] (1) Low cost: The invention uses cost-effective components and materials, such as using 3D printing technology to make the weight module, which not only reduces material waste, but also shortens the production cycle and reduces processing costs; using widely available copper material as the electrode layer, which not only has excellent electrical conductivity, but also has low cost, further reducing the cost of the entire system. In addition, the invention also reduces the demand for complex electronic components through optimized design, avoiding expensive custom components, making the entire electrostatic induction pendulum system more economical and practical. This low-cost feature makes the invention's seismic monitoring equipment can be deployed on a large scale, especially in areas with limited economic conditions or high earthquake-prone areas, providing an efficient and easy-to-popularize earthquake early warning solution.

[0014] (2) Simple structure: The electrostatic induction pendulum of the invention has a simple mechanical structure, easy to maintain and operate, reducing the number of failure points and maintenance requirements. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The overall schematic diagram of the electrostatic induction pendulum device of the invention.

[0016] Figure 2 The schematic diagram of each layer of the electrostatic induction sensor device, from inside to outside is the weight module (1), the connection layer one (2), the electrode layer (3), the connection layer two (4), the electrostatic interaction layer (5).

[0017] Figure 3 The exploded schematic diagram of the electrostatic interaction layer (5) in the sensor device.

[0018] Figure 4 Flowchart of earthquake monitoring and early warning based on electrostatic induction. DETAILED DESCRIPTION

[0019] The working principle of the electrostatic induction pendulum device of the invention is based on the ground movement caused by seismic waves, which are captured by the electrostatic induction sensor of the device and converted into electrical signals. When the seismic wave arrives, the weight module of the device will swing due to ground vibration, causing the relative position between the spatially distributed electric charges and the electric charges on the electrode layer to change. This position change will produce a changing potential difference on the electrode layer. The copper electrode layer sensitively detects these potential differences and converts them into electrical signals. The electrical signals are then transmitted through the conductive circuit to the Keithley 6517B electrometer and the DMM6500 desktop digital touch screen multimeter data acquisition system, which is responsible for collecting and preliminary processing of these signals. The processed signals are sent to the integrated machine learning model, which has been trained to recognize the characteristic patterns of seismic waves. Once a signal pattern related to an earthquake is detected, the system will automatically send an early warning message to the pre-set recipients, thereby achieving early warning of earthquakes.

[0020] In order to better understand the technical solutions in the present application, the following will be described in detail in conjunction with the drawings.

[0021] Case 1: A static induction pendulum for earthquake monitoring and early warning based on static induction, including a weight module (1), a connection layer one (2), an electrode layer (3), a connection layer two (4), and a static interaction layer (5). The material of the weight module (1) is polylactic acid; the materials of the connection layer one (2) and the connection layer two (4) are VHB adhesive tapes; the material of the electrode layer is copper; and the material of the static interaction layer (5) is thermoplastic polyurethane.

[0022] Case 2: The static interaction layer (5) and the electrode layer (3) in the device are firmly bonded by the connection layer two (4), ensuring that these two key layers do not loosen or fall off during long-term use. This design not only guarantees the durability of the equipment, but also ensures that the static induction signals can be transmitted with high sensitivity and accuracy, thereby improving the response speed and accuracy of the earthquake monitoring and early warning system.

[0023] The principles of implementing this technical solution will be further explained as follows:

[0024] In each part of the sensor, the material constituting the static interaction layer (5) itself carries an electric charge, which enhances the static induction signals of the electrode layer (3) during earthquake monitoring and early warning. The selected thermoplastic polyurethane not only has excellent flexibility, wear resistance, and oil resistance, but also exhibits good electrical conductivity, making it an ideal choice for making flexible static interaction layers. The preparation process first involves dissolving polyurethane particles of appropriate particle size and mass in a specific solvent to form a uniform solution under suitable temperature and stirring conditions. Then, the solution is loaded into a syringe or spinner, and electrospinning is performed using a voltage of 12 kV, with a flow rate controlled at 0.8 ml / h and a distance of 18 cm between the needle tip and the collector. During electrospinning, the thermoplastic polyurethane solution is stretched into fibers, which float in the air and accumulate on the collector to form a layer of flexible nanofibers. Finally, the thermoplastic polyurethane film on the collector is gently removed and dried, successfully preparing the thermoplastic polyurethane nanofiber.

[0025] The static induction pendulum is composed of a static induction sensor and a conductive pendulum. The first step in assembly is to use a steel model with a mass of 10.41 g and a projected area of 1.5 cm 2 to explore the vibration characteristics of the static induction pendulum. Then, according to different research needs, three groups of models are manufactured through 3D printing technology: the effective projected area of the first group of models is 10-100 cm 2The 3D printed models were used as the weight module, VHB tape as the adhesive layer, conductive copper tape as the electrode layer, and thermal polyurethane nanofiber as the charge supply layer. Finally, the assembled sensor was connected to the conductive pendulum to complete the assembly process of the entire electrostatically induced pendulum.

[0026] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

[0027] Preferably, the cylindrical model of the weight module (1) is made by 3D printing technology. The mass of the weight module affects the inertia of the pendulum, thereby determining the length of time of oscillation decay. A larger mass will increase the inertia of the pendulum, prolong the decay time, provide a longer time window for capturing seismic waves, but will also affect the response speed of the system to continuous seismic waves; the projected area of the weight module affects air resistance, thereby changing the damping coefficient of the pendulum. A larger projected area will increase air resistance, shorten the decay time, help to quickly stop useless oscillation and prepare to capture the next seismic wave, but may not be conducive to quickly responding to continuous seismic events. By adjusting these parameters, we can optimize the natural frequency of the pendulum to match the seismic waves of a specific frequency, improve the capture ability, and at the same time ensure that the pendulum can quickly return to the equilibrium position after the seismic wave, preparing for the capture of subsequent waves. Therefore, three models with different filling densities were made by 3D printing, and a fixed value of the effective projected area was selected between 10-100 cm2 for each model, and three groups of values were selected for the mass between 10-150 g; further, three models with different projected areas were made by 3D printing, the mass of which remained unchanged in one of the three groups of mass values selected in the first group, and three different values of the effective projected area were selected between 10-100 cm2, meeting the research requirements of studying the damping and resonance characteristics of the electrostatically induced pendulum.

Claims

1. A static induction pendulum for seismic monitoring and early warning based on static induction, comprising a conductive pendulum wire and a pendulum bob, one end of the conductive pendulum wire being fixedly connected to the pendulum bob, characterized in that, The pendulum is cylindrical, the pendulum center is a weight module (1), the outside of the weight module (1) is sequentially connected with a connecting layer one (2), an electrode layer (3), a connecting layer two (4) and an electrostatic interaction layer (5); a part of the conductive pendulum wire is left when the conductive pendulum wire is connected and fixed with the pendulum, and the part is connected with the electrode layer (3), and the conductive pendulum wire is long enough and does not affect the movement of the pendulum at least.

2. The electrostatically induced pendulum for seismic monitoring and warning based on electrostatic induction according to claim 1, characterized in that: The cylindrical model of the weight module (1) is made by 3D printing technology, and the material is polylactic acid.

3. The electrostatically induced pendulum for seismic monitoring and warning based on electrostatic induction according to claim 2, characterized in that: The effective projection area of the weight module (1) is between 10-100 cm 2 and the mass is between 10-150 g.

4. The electrostatically induced pendulum for seismic monitoring and warning based on electrostatic induction according to claim 3, characterized in that: The materials of the connecting layer one (2) and the connecting layer two (4) are VHB adhesive tapes, which respectively bond the weight module (1) and the electrode layer (3), and the electrode layer (3) and the electrostatic interaction layer (5) together.

5. The electrostatically induced pendulum for seismic monitoring and warning based on electrostatic induction according to claim 4, characterized in that: The electrode layer (3) is made of copper.

6. The electrostatically induced pendulum for seismic monitoring and warning based on electrostatic induction according to claim 5, characterized in that: The electrostatic interaction layer (5) is prepared by thermoplastic polyurethane through electrospinning technology.

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