A node geophone buried coupling pressure evaluation device and method

Abstract

This invention belongs to the field of seismic exploration technology, specifically disclosing a device and method for evaluating the coupling pressure of a nodal geophone. The device includes a pressure sensor plate and a pressure value display device equipped with a nodal quality control APP. The pressure sensor plate is attached and fixed to the outer surface of the nodal geophone housing, and its power cable is connected to the power supply of the nodal geophone. The pressure sensor plate communicates with the pressure value display device through the nodal geophone's signal acquisition module and Bluetooth / NFC module. The method uses the pressure sensor plate to detect the pressure at the target location in real time and sends the results to the pressure value display device via the nodal geophone. Finally, the operator performs a stress analysis on the nodal geophone based on the content displayed in the nodal quality control APP. This invention can quantitatively evaluate the coupling effect of the nodal geophone body, improve data quality, and can be widely applied in the nodal geophone installation process during seismic exploration.

Description

Technical Field

[0001] This invention belongs to the field of seismic exploration technology and relates to a device and method for evaluating the embedded coupling pressure of nodal geophones. Background Technology

[0002] With the widespread application of "two-width and one-height" seismic exploration technology, the number of online channels is increasing. However, wired acquisition instruments have a small number of channels and poor adaptability to complex terrain, making it difficult to meet the needs of "two-width and one-height" seismic exploration. In particular, construction safety risks are high and construction efficiency is low in complex mountainous areas.

[0003] This necessitates a convenient and efficient wireless nodal instrument to improve field productivity and ensure data quality during construction in complex mountainous areas. However, nodal acquisition instruments cannot monitor their operational status or view seismic data in real time, posing challenges to nodal detector placement, timely QC retrieval and inspection, data quality control, and efficient analysis. Especially with the widespread application of nodal acquisition, some tools and devices have been invented to improve the body coupling placement method of nodal detectors, but these tools and devices still cannot quantitatively evaluate the body coupling placement effect. Summary of the Invention

[0004] The purpose of this invention is to provide a device for evaluating the coupling pressure of a node detector, which solves the problem that the coupling effect of the node detector body could not be quantitatively evaluated by relying on manual experience to judge it.

[0005] Another objective of this invention is to provide a method for evaluating the coupling pressure of a node detector embedded in the ground using the aforementioned device for evaluating node detector embedded coupling pressure, so as to achieve quantitative evaluation of the coupling embedding effect of the node detector body and improve data quality.

[0006] To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0007] A nodal detector embedded coupling pressure evaluation device includes N pressure sensor chips and a pressure value display device equipped with a nodal quality control APP; wherein, N≥2;

[0008] N pressure sensor pieces are attached and fixed at equal intervals on the outer surface of the nodal detector housing. The power lines of the pressure sensor pieces are connected to the power supply of the nodal detector, and the signal output terminals of the pressure sensor pieces are connected to the signal input terminals of the signal acquisition module of the nodal detector.

[0009] The signal acquisition module is connected to the pressure value display device via the Bluetooth or NFC module of the node detector.

[0010] As a limitation, the back of the pressure sensor sheet is attached and fixed to the tail cone of the nodal detector, while the front of the pressure sensor sheet is exposed and in full contact with the soil of the surrounding rock at the target location.

[0011] The front side of the pressure sensor sheet refers to the sensitive side.

[0012] As a second definition, the pressure sensor chip includes an elastic sensitive element for sensing pressure signals, as well as a conversion element and a signal conditioning circuit;

[0013] The signal output terminal of the elastic sensitive element is connected to the signal input terminal of the conversion element, the signal output terminal of the conversion element is connected to the signal input terminal of the signal conditioning circuit, and the signal output terminal of the signal conditioning circuit is connected to the signal input terminal of the signal acquisition module of the node detector.

[0014] The method for evaluating the coupling pressure of a buried node detector is implemented using the aforementioned device for evaluating the coupling pressure of a buried node detector. The method is carried out in the following steps:

[0015] S1. The pressure sensor chip detects the pressure at the target location in real time and outputs the result to the signal acquisition module of the node detector.

[0016] S2. The signal acquisition module further processes the received data and then sends it to the pressure value display device via Bluetooth or NFC module.

[0017] In this process, the coupling pressure of the medium on the node detector is calculated according to equation ①.

[0018] F couple =F normal +F friction,normal ①

[0019] In the formula, F normal F represents the normal force exerted by the medium on the nodal detector. friction,normal This represents the frictional force exerted by the medium on the nodal detector;

[0020] Then, based on the coupling pressure F couple Further calculations were performed on the theoretical value P of the coupling stress experienced by the nodal detector. couple and the average value detected by the sensor chip

[0021] Among them, P couple =F couple / S, where S is the surface area of ​​the cone of the nodal detector. H is the height of the cone section of the node detector; R is the maximum radius of the cone of the node detector.

[0022] S3. The pressure value display device displays the stress status of the node detector through the built-in node quality control APP;

[0023] In this step, the stress condition includes the theoretical value P of the coupling stress on the nodal detector. couple and the average value detected by the sensor chip

[0024] S4. Staff members perform stress analysis on the nodal detector based on the described stress conditions.

[0025] if This indicates that the nodal detector and the ground have good coupling.

[0026] if This indicates undercoupling between the node detector and the ground;

[0027] In step S2, the coupling pressure of the medium on the node detector is calculated according to equation ①.

[0028] F couple =F normal +F friction,normal ①

[0029] In the formula, F normal F represents the normal force exerted by the medium on the nodal detector. friction,normal This represents the frictional force exerted by the medium on the nodal detector;

[0030] The normal force of the medium on the nodal detector is calculated according to equation ②.

[0031]

[0032] Where H is the height of the cone portion of the node detector, h is the overall height of the node detector, x is the vertical distance from the cone tip of the node detector, r(x) is the cone radius at x, γ is the unit volume weight of the medium, and θ is the half cone angle of the cone portion of the node detector.

[0033] The frictional force of the medium on the nodal detector is calculated according to equation ③.

[0034] F friction,normal =∫0 H γ(hx)tan(δ)2πr(x)dx=((πγtan(δ)tanθ) / 3)H 2 (3h-2H)③

[0035] In the formula, tan(δ) represents the coefficient of friction between the cone and the medium.

[0036] As a limitation, step S2 also includes the process of calculating the uniformity of pressure distribution according to equation ④:

[0037]

[0038] Further calculate the relative uniformity of force according to equation ⑤:

[0039]

[0040] As a further limitation, in step S3, the force condition includes relatively uniform force distribution;

[0041] In step S4, if C ≤ 10%, it indicates that the pressure distribution is uniform; if C > 10%, it indicates that the pressure distribution is uneven, and there may be poor contact or local pressure concentration.

[0042] As a second definition, the pressure sensor chip includes an elastic sensitive element for sensing pressure signals, as well as a conversion element and a signal conditioning circuit;

[0043] The signal output terminal of the elastic sensitive element is connected to the signal input terminal of the conversion element, the signal output terminal of the conversion element is connected to the signal input terminal of the signal conditioning circuit, and the signal output terminal of the signal conditioning circuit is connected to the signal input terminal of the signal acquisition module of the node detector.

[0044] Step S1 is performed in the following order:

[0045] S11. The pressure sensor sheet senses pressure changes at the target location through an elastic sensitive element and generates corresponding deformation.

[0046] S12. The conversion element generates a corresponding resistance change according to the deformation;

[0047] S13. The signal conditioning circuit receives the analog signal of the resistance change, converts it into a digital signal, and outputs it to the signal acquisition module of the node detector.

[0048] The present invention, by adopting the above-described technical solution, achieves the following technical advancements compared to existing technologies:

[0049] (1) Existing technologies either rely on manual experience to judge the coupling embedding effect of the node detector body, which cannot intuitively determine the coupling embedding effect of the node detector body; or use a tension spring scale to pull the embedded node detector to judge the coupling embedding effect of the node detector body, which is not only cumbersome, time-consuming and labor-intensive, but also makes the body coupling embedding effect of the node detector worse when it is pulled; the present invention sets a pressure sensor to detect the pressure at the target position of the node detector, and displays the test results quantitatively through a pressure value display device with a node quality control APP installed. This allows staff to intuitively view the force value of the node detector and perform force analysis on a single node detector to determine whether the actual embedding of the node detector is good. This achieves quantitative evaluation of the coupling embedding effect of the node detector body and improves the data quality.

[0050] (2) In this invention, the back of the pressure sensor sheet is attached and fixed to the tail cone of the node detector, and the front of the pressure sensor sheet is exposed and in full contact with the soil of the surrounding rock of the target location, so as to achieve accurate measurement of the buried pressure.

[0051] (3) In this invention, the pressure sensor chip includes an elastic sensitive element for sensing pressure signals, as well as a conversion element and a signal conditioning circuit. The circuit structure is simple. It is powered directly by a node detector. At the same time, it sends the acquisition results to the pressure value display device by means of the signal acquisition module and Bluetooth / NFC module of the node detector. This greatly simplifies the circuit structure of the entire device, reduces the cost and the difficulty of the layout of the entire device.

[0052] This invention belongs to the field of seismic exploration technology and can quantitatively evaluate the coupling and embedding effect of nodal geophones, thereby improving data quality. Attached Figure Description

[0053] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0054] In the attached diagram:

[0055] Figure 1 This is a schematic diagram of the structure of the pressure sensor chip in Embodiment 1 of the present invention;

[0056] Figure 2 This is a circuit block diagram of the pressure sensor chip in Embodiment 1 of the present invention;

[0057] Figure 3 This is a schematic diagram of the installation of the pressure sensor chip in Embodiment 1 of the present invention;

[0058] Figure 4 This is a schematic diagram of the parameters of the node detector in Embodiment 2 of the present invention.

[0059] In the diagram: 1. Sensor electrode, 2. Sensor chip, 3. Coccyx. Detailed Implementation

[0060] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0061] Example 1: A device for evaluating the embedded coupling pressure of a node detector

[0062] This embodiment includes a pressure sensor chip and a pressure value display device equipped with a node quality control APP.

[0063] Among them, N pressure sensor pieces are evenly spaced and fixed to the outer surface of the nodal detector housing. For example... Figure 3 As shown, to achieve accurate measurement of the burial pressure, in this embodiment, the back of the pressure sensor sheet is attached and fixed around the tail cone 3 of the nodal detector, while the front of the pressure sensor sheet is exposed and in full contact with the soil of the surrounding rock at the target location. The front of the pressure sensor sheet refers to the sensitive surface. N ≥ 2.

[0064] The power supply cable of the pressure sensor is connected to the power supply of the node detector, which powers the pressure sensor. The signal output terminal of the pressure sensor is connected to the signal input terminal of the signal acquisition module of the node detector; the signal acquisition module communicates with the pressure value display device through the Bluetooth or NFC module of the node detector.

[0065] like Figures 1 to 3 As shown, in this embodiment, the pressure sensor chip includes a sensor electrode 1 made of an elastic sensitive element for sensing pressure signals, and a sensor chip 2 containing a conversion element and a signal conditioning circuit. The signal output terminal of the elastic sensitive element is connected to the signal input terminal of the conversion element, the signal output terminal of the conversion element is connected to the signal input terminal of the signal conditioning circuit, and the signal output terminal of the signal conditioning circuit is connected to the signal input terminal of the signal acquisition module of the node detector.

[0066] Pressure sensor chips typically comprise a thin film material, which can be a metal or a polymer. This film usually possesses a certain degree of flexibility and elasticity. When external pressure or force is applied to the sensor's surface, the thin film material undergoes slight deformation or bending. This deformation is proportional to the external pressure, causing a change in the resistance value of the resistive layer. This change can be an increase or decrease in resistance. The thin film material is typically coated or infused with a conductive material, such as metal or carbon. When the film bends, the resistance of the conductive material changes. This resistance change is proportional to the degree of bending of the film. Specifically, in this embodiment, the pressure sensor chip uses a thin film pressure sensor sold by Shenzhen Baoshengda Technology Co., Ltd.

[0067] In this embodiment, the node quality control APP is the node detector quality control APP of China National Petroleum Corporation Eastern Geophysical Exploration Co., Ltd., which can be directly installed on mobile terminals such as mobile phones.

[0068] Example 2: Evaluation Method for Buried Coupling Pressure of Node Detectors

[0069] This embodiment uses Embodiment 1 for implementation, and the method is performed in the following steps:

[0070] S1. The pressure sensor chip detects the pressure at the target location in real time and outputs the result to the signal acquisition module of the node detector.

[0071] S2. The signal acquisition module further processes the received data and then sends it to the pressure value display device via Bluetooth or NFC module.

[0072] S3. The pressure value display device displays the stress status of the node detector through the built-in node quality control APP;

[0073] S4. Staff members perform stress analysis on the nodal detector based on the stress conditions.

[0074] Step S1 is performed in the following order:

[0075] S11. The pressure sensor sheet senses pressure changes at the target location through an elastic sensitive element and generates corresponding deformation.

[0076] S12, The conversion element generates a corresponding resistance change based on the deformation;

[0077] S13. The signal conditioning circuit receives the analog signal of the above resistance change, converts it into a digital signal and outputs it to the signal acquisition module of the node detector.

[0078] Finally, staff can see whether each node detector is properly embedded according to the information displayed on the node quality control APP, and can perform stress analysis on a single node detector to quantitatively evaluate the coupling embedding effect of the node detector body and improve data quality.

[0079] Specifically, the mathematical expression of the pressure sensor element is usually related to the working principle of the strain gauge sensor. Based on the fundamental principles of materials mechanics, the working principle of the strain gauge sensor is based on Hooke's Law, which describes the relationship between the deformation and stress of a material under external force. Building upon this, the relationship between the change in resistance and stress / strain is derived using the resistance law and the piezoresistive effect. The voltage signal is then calculated and output using a bridge circuit resistance measurement method. Simultaneously, based on the correlation between the coupling performance of the seismic nodal geophone and the pressure between it and the surrounding medium, a stress analysis is performed on the nodal geophone. The theoretical coupling pressure is calculated using theoretical formulas. A novel approach is proposed to determine the coupling between the nodal geophone and the ground by comprehensively comparing the theoretically calculated coupling pressure with the average pressure of the pressure sensor element and the pressure uniformity. Its mathematical expression is as follows:

[0080] Strain: Strain is the relative deformation of a material, usually a dimensionless physical quantity. In this embodiment, the pressure sensor patch is a patch pressure sensor, which is proportional to the externally applied pressure. Strain can be expressed using the following formula:

[0081] ε=(Δl / l0) (1)

[0082] ε 径 =-με (2)

[0083] Where ε represents axial strain, Δl represents the change in material length, and l0 represents the original length when unstressed. 径 denoted by radial strain, μ represents Poisson's ratio.

[0084] Stress: Stress is the force per unit area, usually measured in Pascals (Pa). It is proportional to the external pressure applied to the pressure sensor plate. Stress can be expressed using the following formula:

[0085] σ= (F / A) (3)

[0086] Where σ represents stress, F represents the force applied to the pressure sensor element, and A represents the area of ​​the pressure sensor element under stress. Furthermore, based on Hooke's Law, the relationship between stress and strain is expressed as:

[0087] σ=Eε (4)

[0088] Where E represents the elastic modulus of the material.

[0089] Resistance: According to the law of resistance, for a pressure sensor material with resistivity ρ, length l, and cross-sectional area s, its resistance can be expressed by the following formula:

[0090] R=ρ(l / s) (5)

[0091] Resistance change: When the pressure sensor material is subjected to pressure, its l, s, and ρ will all change. Therefore, taking the logarithm and derivative of formula (5) yields the relative change in resistance:

[0092] (dR) / R=(dρ) / ρ+(dl) / l-(ds) / s (6)

[0093] The relative change in resistivity is proportional to the applied stress, and can be expressed by the following formula:

[0094] (dρ) / ρ=πσ (7)

[0095] Where π represents the piezoresistive coefficient of the pressure sensor material, and σ represents the stress.

[0096] In summary, equation (6) can be expressed as:

[0097] (dR) / R=(dρ) / ρ+(1+2μ)ε=(1+2μ+πE)ε (8)

[0098] Generally, the resistivity change caused by changes in material dimensions can be ignored. The resistivity change is mainly due to the effect of stress, so πE is much greater than 1+2μ. Therefore, the resistivity change caused by changes in geometric dimensions can be ignored. Thus, the change in resistance can be expressed by the following formula:

[0099] (dR) / R=(dρ) / ρ=πσ=πEε (9)

[0100] ΔR=πEεR0 (10)

[0101] Where R0 is the resistance when no pressure is applied.

[0102] Output signal: When measuring resistance using the bridge method, changes in resistance cause changes in voltage in the resistance bridge, and the output signal is usually expressed as voltage.

[0103] When the bridge is balanced, V out =0, at this time the resistance ratio of adjacent bridge arms is equal:

[0104] R1 / R4=R2 / R3 (11)

[0105] When the resistance value of R1 changes (i.e., R′1=R1+ΔR1), let R1 / R4=R2 / R3=m, then

[0106] V out =m / ((1+m) 2 )·(ΔR1) / (R1)·V exc (12)

[0107] Among them, V out Indicates the output signal, V exc ΔR1 represents the excitation voltage, and ΔR1 represents the change in resistance.

[0108] In this embodiment, the coupling pressure F couple It is the force exerted by the medium on the cone surface of the node detector, including the normal force of the medium on the node detector and the normal component of the frictional force. Based on equations (1) and (2), and combined with the distribution pattern of the coupling pressure of the node detector, equation (13) is derived. This coupling pressure is the superposition of the normal force of the medium on the detector and the normal component of the frictional force, and can be expressed as:

[0109] F couple =F normal +F friction,normal (13)

[0110] According to equation (13), the normal force exerted by the medium on the cone surface of the nodal detector is determined by the properties of the medium and the geometry of the cone. Figure 4 We can obtain,

[0111]

[0112] P normal =γ(hx) (15)

[0113] r(x)=xtanθ (16)

[0114] Based on equations (15) and (16), equation (14) can be expressed as:

[0115]

[0116] Where H is the height of the cone portion of the node detector, h is the overall height of the node detector, x is the vertical distance from the cone tip of the node detector, r(x) is the cone radius at x, γ is the unit volume weight of the medium, and θ is the semi-cone angle of the cone portion of the node detector.

[0117] The normal component of the frictional force in equation (13) can be expressed as:

[0118]

[0119] Wherein, tan(δ) represents the coefficient of friction between the cone and the medium.

[0120] Therefore, according to equations (17) and (18), equation (13) can be expressed as:

[0121] F couple =(πγtanθ / 3)H 2 (3h-2H)+((πγtan(δ)tanθ) / 3)H 2 (3h-2H) (19)

[0122] Coupled stress (P) couple ): The coupling stress acting per unit area of ​​the nodal detector cone. Based on equation (3), the expression for the coupling stress can be obtained:

[0123] P couple =F couple / S (20)

[0124] Where S is the surface area of ​​the cone of the nodal detector. R represents the maximum radius of the node detector cone.

[0125] Pressure sensor data processing: Pressure sensor pieces are evenly arranged on the surface of the cone. The resistance change ΔR of the pressure sensor pieces can be obtained based on the output signal of equation (12). The local pressure measurement value P provided by different sensors can be obtained based on the relationship between the resistance change and stress of equation (9). sensor,i (i = 1, 2, 3, ..., N), the average pressure can be calculated:

[0126]

[0127] Coupling determination: The coupling of the nodal detector is determined by comparing the theoretical value of the coupling stress with the average value detected by the sensor.

[0128] if This indicates that there is good coupling between the node detector and the ground.

[0129] if This indicates undercoupling between the node detector and the ground.

[0130] Furthermore, the uniformity of pressure distribution can be calculated: the uniformity of pressure distribution is calculated using the standard deviation.

[0131]

[0132] Relative uniformity:

[0133]

[0134] If C ≤ 10%, it indicates that the pressure distribution is uniform; if C > 10%, it indicates that the pressure distribution is uneven, which may indicate poor contact or local pressure concentration.

Claims

1. A device for evaluating the embedded coupling pressure of a node detector, characterized in that, It includes N pressure sensor chips and a pressure value display device equipped with a node quality control APP; where N≥2; N pressure sensor pieces are attached and fixed at equal intervals on the outer surface of the nodal detector housing. The power lines of the pressure sensor pieces are connected to the power supply of the nodal detector, and the signal output terminals of the pressure sensor pieces are connected to the signal input terminals of the signal acquisition module of the nodal detector. The signal acquisition module is connected to the pressure value display device via the Bluetooth or NFC module of the node detector.

2. The nodal detector embedded coupling pressure evaluation device according to claim 1, characterized in that, The back of the pressure sensor chip is attached and fixed to the tail cone of the nodal detector, while the front of the pressure sensor chip is exposed and in full contact with the soil of the surrounding rock at the target location. The front side of the pressure sensor sheet refers to the sensitive side.

3. The nodal detector embedded coupling pressure evaluation device according to claim 1 or 2, characterized in that, The pressure sensor chip includes an elastic sensitive element for sensing pressure signals, as well as a conversion element and signal conditioning circuitry; The signal output terminal of the elastic sensitive element is connected to the signal input terminal of the conversion element, the signal output terminal of the conversion element is connected to the signal input terminal of the signal conditioning circuit, and the signal output terminal of the signal conditioning circuit is connected to the signal input terminal of the signal acquisition module of the node detector.

4. A method for evaluating the coupling pressure of a buried node detector, implemented using the device for evaluating the coupling pressure of a buried node detector as described in any one of claims 1 to 3, characterized in that... This method is performed in the following steps in sequence: S1. The pressure sensor chip detects the pressure at the target location in real time and outputs the result to the signal acquisition module of the node detector. S2. The signal acquisition module further processes the received data and then sends it to the pressure value display device via Bluetooth or NFC module. In this process, the coupling pressure of the medium on the node detector is calculated according to equation ①. F couple =F normal +F friction，normal ① In the formula, F normal F represents the normal force exerted by the medium on the nodal detector. friction，nomal This represents the frictional force exerted by the medium on the nodal detector; Then, based on the coupling pressure F couple Further calculations were performed on the theoretical value P of the coupling stress experienced by the nodal detector. couple and the average value detected by the sensor chip Among them, P couple =F couple / S, where S is the surface area of ​​the cone of the nodal detector. H is the height of the cone section of the node detector; R is the maximum radius of the cone of the node detector. S3. The pressure value display device displays the stress status of the node detector through the built-in node quality control APP; In this step, the stress condition includes the theoretical value P of the coupling stress on the nodal detector. couple and the average value detected by the sensor chip S4. Staff members perform stress analysis on the nodal detector based on the described stress conditions. if This indicates that the nodal detector and the ground have good coupling. if This indicates undercoupling between the node detector and the ground; In step S2, the coupling pressure of the medium on the node detector is calculated according to equation ①. F couple =F normal +F friction，normal ① In the formula, F normal F represents the normal force exerted by the medium on the nodal detector. friction，normal This represents the frictional force exerted by the medium on the nodal detector; The normal force of the medium on the nodal detector is calculated according to equation ②. Where H is the height of the cone portion of the node detector, h is the overall height of the node detector, x is the vertical distance from the cone tip of the node detector, r(x) is the cone radius at x, γ is the unit volume weight of the medium, and θ is the half cone angle of the cone portion of the node detector. The frictional force of the medium on the nodal detector is calculated according to equation ③. In the formula, tan(δ) represents the coefficient of friction between the cone and the medium.

5. The method for evaluating the coupling pressure of a node detector buried according to claim 4, characterized in that, Step S2 also includes the process of calculating the uniformity of pressure distribution according to equation ④: Further calculate the relative uniformity of force according to equation ⑤:

6. The method for evaluating the coupling pressure of a node detector buried according to claim 5, characterized in that, In step S3, the force condition includes the relative uniformity of the force. In step S4, if C ≤ 10%, it indicates that the pressure distribution is uniform; if C > 10%, it indicates that the pressure distribution is uneven, and there may be poor contact or local pressure concentration.

7. The method for evaluating the embedded coupling pressure of a node detector according to any one of claims 4 to 6, characterized in that, The pressure sensor chip includes an elastic sensitive element for sensing pressure signals, as well as a conversion element and signal conditioning circuitry; The signal output terminal of the elastic sensitive element is connected to the signal input terminal of the conversion element, the signal output terminal of the conversion element is connected to the signal input terminal of the signal conditioning circuit, and the signal output terminal of the signal conditioning circuit is connected to the signal input terminal of the signal acquisition module of the node detector. Step S1 is performed in the following order: S11. The pressure sensor sheet senses pressure changes at the target location through an elastic sensitive element and generates corresponding deformation. S12. The conversion element generates a corresponding resistance change according to the deformation; S13. The signal conditioning circuit receives the analog signal of the resistance change, converts it into a digital signal, and outputs it to the signal acquisition module of the node detector.

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