Ceramic capacitive pressure sensor and application method thereof

Abstract

The invention discloses a ceramic capacitive pressure sensor, which comprises a packaging shell, a commercial small circular shell is arranged on the packaging shell, a copper pipe is arranged on one side, far away from the packaging shell, of the commercial small circular shell, an electronic wire is arranged on the packaging shell in a penetrating manner, and the electronic wire is connected with the packaging shell. The insulating paper, the inner copper body and the check ring are integrally designed into the combined base with the PPS and the glass fiber wrapping the SUS metal inner container, a traditional multi-part manual assembly structure is replaced, and compared with the scheme that in the prior art, insulating paper and an inner copper body shielding cover need to be bonded, the number of parts is reduced, and the cost is reduced. The cost is reduced, meanwhile, automatic injection molding is achieved, manual assembly errors are avoided, the assembly efficiency is improved, the compression strength of the PPS composite reinforcing material is improved compared with that of traditional insulation paper, and the reliability in the high-pressure-resistant environment is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressure sensors, and in particular relates to a ceramic capacitive pressure sensor and an application method thereof. Background Art

[0002] With the rapid development of industrial automation, environmental monitoring and other fields, the performance requirements for pressure sensors are getting higher and higher. Existing pressure sensors need to be bent and bypassed around ceramic capacitors and bases during assembly, which makes the product structure complex and expensive. The process manufacturing is difficult to achieve automated assembly, reducing assembly efficiency. The insulation material used has limited pressure resistance and is difficult to meet the needs of high-pressure scenarios. In terms of electromagnetic shielding, the sleeve-type shielding shell has a bottom shielding blind area, resulting in poor EMI shielding effect. In strong electromagnetic environments such as commercial air conditioning and energy storage refrigeration, the sensor signal is easily interfered with and the measurement is inaccurate. At the same time, the sealing performance of the traditional structure is insufficient, and it cannot effectively resist the leakage of fluid media, and it is difficult to adapt to complex working conditions. In addition, some sensors are sensitive to temperature changes and lack accurate temperature compensation mechanisms. The measurement errors at different temperatures are significant, making it difficult to meet high-precision measurement requirements. Summary of the Invention

[0003] The object of the present invention is to provide a ceramic capacitive pressure sensor to solve the problems raised in the above background technology.

[0004] In a first aspect, the present invention provides a ceramic capacitive pressure sensor, comprising: It includes a packaging shell, on which a small hollow circular shell is provided, a copper tube is provided on the side of the small hollow circular shell away from the packaging shell, an electronic wire is passed through the packaging shell, a small hollow combination base is provided inside the small hollow shell, a metal inner shell of the combination base is provided inside the small hollow combination base, a capacitor is provided inside the side of the small hollow combination base close to the metal inner shell of the combination base, an FPC flexible circuit board is provided inside the packaging shell, and a small hollow terminal is provided on the small hollow combination base.

[0005] In a possible implementation of the first aspect, a terminal pin is provided on the small circular terminal of the commercial space, an electronic wire is inserted into the packaging shell, an end of the terminal pin away from the small circular terminal of the commercial space is connected to the electronic wire, and the metal inner shell of the commercial space combination base is embedded in the small circular combination base of the commercial space to form a cup-shaped electromagnetic shielding structure.

[0006] In a possible implementation of the first aspect, the small circular terminal button and the small circular combination base are buckled into a whole, and the FPC flexible circuit board is located inside.

[0007] In a possible implementation of the first aspect, one end of the terminal pin close to the small circular terminal is electrically connected to an FPC flexible circuit board, and the FPC flexible circuit board is electrically connected to the capacitor.

[0008] In a possible implementation of the first aspect, a sealing ring is installed between the commercial small circular assembly base and the commercial small circular shell, and the copper tube passes through the commercial small circular shell and is connected to the pressure-sensing end of the capacitor.

[0009] In a possible implementation of the first aspect, the commercial space small circular combination base is made of PPS composite reinforced material, and the metal inner shell of the commercial space combination base is cup-shaped and has a stainless steel inner liner structure.

[0010] Compared with the prior art, the present invention provides a ceramic capacitive pressure sensor with the following advantages: 1. The present invention integrates the insulating paper, inner copper body and retaining ring into a combined base of PPS + glass fiber wrapped SUS304 metal liner, replacing the traditional multi-part manual assembly structure. Compared with the solution in the prior art that requires bonding the insulating paper and inner copper body shielding cover, the number of parts is reduced and the cost is reduced. At the same time, automated injection molding is realized to avoid manual assembly errors and improve assembly efficiency. The compressive strength of the PPS composite reinforced material is higher than that of traditional insulating paper, ensuring reliability in high-voltage environments.

[0011] 2. The cup-shaped electromagnetic shielding structure formed by the metal inner shell of the commercial air combination base embedded in the combination base replaces the traditional sleeve-type shielding shell, which solves the problem of incomplete bottom shielding in the existing technology and improves the EMI shielding effect. At the same time, the overall insulation structure formed by the combination base and the end button, combined with the sealing design of the sealing ring 8, enables the sensor to resist fluid medium leakage and ensure signal transmission stability in complex electromagnetic environments in commercial air-conditioning, energy storage refrigeration and other industries. Compared with traditional structures, it is more adaptable to high-voltage and strong interference conditions.

[0012] In a second aspect, the present invention provides a control method for a ceramic capacitive pressure sensor, comprising: Performing multi-frequency measurement on the capacitance of the pressure sensor in the pressure environment to be measured to obtain raw capacitance response data, and extracting capacitance response features from the raw capacitance response data; Based on the capacitance response characteristics, the dielectric gradient tensor and the plate deformation topology characteristics corresponding to the capacitance are analyzed to determine a pressure tolerance threshold of the pressure environment to be measured, and the coupling interference coefficients between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topology characteristics are calculated to obtain a dielectric pressure drift coefficient and a deformation pressure drift coefficient; Acquire the capacitance structure data and temperature compensation coefficient of the capacitor, combine the dielectric pressure drift coefficient, the deformation pressure drift coefficient and the capacitance structure data, construct a pressure response calibration matrix of the capacitor, generate an output drive instruction of the pressure sensor based on the pressure response calibration matrix, perform capacitance-voltage conversion of the capacitor according to the output drive instruction, and output a calibrated pressure measurement value.

[0013] In a possible implementation of the second aspect, extracting the capacitance response feature from the original capacitance response data includes: Analyzing the measurement frequency conditions corresponding to the original capacitance response data; Querying an initial capacitance value corresponding to the pressure sensor under the measurement frequency condition; Analyzing the capacitance-pressure sensitivity characteristic corresponding to the initial capacitance value; Based on the capacitance-pressure sensitivity characteristic, identifying capacitance frequency response data corresponding to the pressure sensor; Capacitance response features in the original capacitance response data are extracted based on the capacitance frequency response data.

[0014] In a possible implementation of the second aspect, respectively calculating the coupling interference coefficients between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topological feature to obtain the dielectric pressure drift coefficient and the deformation pressure drift coefficient includes: detecting a current pressure value corresponding to the dielectric gradient tensor and the plate deformation topological feature; Combining the current pressure value and the pressure tolerance threshold, the coupling interference coefficient between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topological characteristics is calculated using the following formula to obtain the dielectric pressure drift coefficient and the deformation pressure drift coefficient: ; ; Where A represents the dielectric pressure drift coefficient, represents the gradient minimum in the dielectric gradient tensor, represents the dielectric velocity tensor, Indicates the pressure tolerance threshold, E indicates the current pressure value, and B indicates the deformation pressure drift coefficient. represents the partial derivative of the plate deformation topological characteristics with respect to the pressure value, Represents the topological characteristics of plate deformation.

[0015] In a possible implementation of the second aspect, constructing a pressure response calibration matrix of the capacitor by combining the dielectric pressure drift coefficient, the deformation pressure drift coefficient, and the capacitor structure data includes: Performing multi-dimensional feature encoding on the capacitor structure data to obtain a structural feature quantum state; Performing physical field mapping processing on the dielectric pressure drift coefficient and the deformation pressure drift coefficient to obtain a drift coefficient distribution matrix; Performing a fusion calibration process on the structural characteristic quantum state and the drift coefficient distribution matrix to obtain a calibration primitive group; A tensor decomposition process is performed on the calibration primitive group to obtain a pressure response calibration matrix of the capacitor.

[0016] It can be seen that the present invention can accurately reveal the law and trend of the change of capacitance of the pressure sensor with pressure and frequency under actual pressure environment by extracting the capacitance response characteristics from the original capacitance response data, providing a core basis for quantifying the pressure-capacitance relationship and evaluating sensor performance, so that pressure detection can deeply reflect the dynamic response process of the sensor and improve the sensitivity of the detection results to the actual pressure changes. Based on the capacitance response characteristics, the present invention analyzes the dielectric gradient tensor and the plate deformation topological characteristics corresponding to the capacitance, which can deeply understand the internal physical change mechanism of the pressure sensor, analyze the influence of pressure on the capacitance from the dual dimensions of dielectric properties and structural deformation, and provide a theoretical basis for accurately evaluating sensor performance and optimizing design. It is clear that by obtaining the capacitance structure data and temperature compensation coefficient of the capacitor, combining the dielectric pressure drift coefficient, the deformation pressure drift coefficient and the capacitance structure data, a pressure response calibration matrix of the capacitor is constructed. The capacitor's own structural characteristics, the influence of ambient temperature and the dielectric and deformation drift factors caused by pressure can be integrated to establish an accurate pressure-capacitance response correlation model, providing a basis for accurate calibration of pressure measurement. The output drive instruction of the pressure sensor is generated based on the pressure response calibration matrix, and the capacitance-voltage conversion of the capacitor is executed according to the output drive instruction. The calibrated pressure measurement value is output, realizing a closed loop from the theoretical model to the actual measurement calibration, effectively eliminating multi-factor interference, and improving the measurement accuracy of the pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 A schematic diagram of the three-dimensional structure of a ceramic capacitive pressure sensor according to an embodiment of the present invention; Figure 2 A schematic diagram of the internal structure of a ceramic capacitive pressure sensor according to an embodiment of the present invention; Figure 3 A schematic cross-sectional view of the three-dimensional structure of a ceramic capacitive pressure sensor according to an embodiment of the present invention; Figure 4This is a schematic diagram of the commercial space small circular combined base structure proposed in one embodiment of the present invention; Figure 5 This is a schematic cross-sectional view of a commercial space small circular combined base structure proposed in one embodiment of the present invention; Figure 6 This is a schematic diagram of the commercial hollow small circular terminal structure proposed in one embodiment of the present invention; Figure 7 This is a schematic cross-sectional view of a commercial space small circular combined base structure proposed in one embodiment of the present invention; Figure 8 A flow chart of a control method for a ceramic capacitive pressure sensor according to an embodiment of the invention; In the figure: 1. Commercial small circular terminal; 2. Terminal pin; 3. Commercial small circular assembly base; 4. Commercial assembly base metal inner shell; 5. Commercial small circular shell; 6. FPC flexible circuit board; 7. Capacitor; 8. Sealing ring; 9. Copper tube; 10. Package shell; 11. Electronic wire. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] See also Figure 1 , is a schematic diagram of the three-dimensional structure of a ceramic capacitive pressure sensor proposed in one embodiment of the present invention, including a packaging shell 10, characterized in that a hollow small circular shell 5 is provided on the packaging shell 10, a copper tube 9 is provided on the side of the hollow small circular shell 5 away from the packaging shell 10, an electronic wire 11 is passed through the packaging shell 10, and the hollow small circular shell 5 and the packaging shell 10 are integrally formed by an injection molding process to ensure structural sealing and pressure resistance.

[0020] See also Figure 2, is a schematic diagram of the internal structure of a ceramic capacitive pressure sensor proposed in one embodiment of the present invention, wherein a commercial small circular shell 5 is provided with a commercial small circular assembly base 3, and a commercial small circular assembly base metal inner shell 4 is provided inside the commercial small circular assembly base 3, and a capacitor 7 is provided inside the commercial small circular assembly base 3 on the side close to the commercial small circular assembly base metal inner shell 4, and an FPC flexible circuit board 6 is provided inside the package shell 10, and a commercial small circular assembly base 3 is provided with a commercial small circular terminal 1, and a terminal pin 2 is provided on the commercial small circular terminal 1, and an electronic wire 11 is inserted into the package shell 10, and the end of the terminal pin 2 away from the commercial small circular terminal 1 is connected to the electronic wire 11, and the end of the terminal pin 2 close to the commercial small circular terminal 1 is electrically connected to the FPC flexible circuit board 6, the commercial small circular terminal 1 and the commercial small circular assembly base 3 are buckled into a whole, and the FPC flexible circuit board 6 is located inside it. , the FPC flexible circuit board 6 is electrically connected to the capacitor 7, the commercial space combination base metal inner shell 4 is embedded in the commercial space small circular combination base 3 to form a cup-shaped electromagnetic shielding structure, a sealing ring 8 is installed between the commercial space small circular combination base 3 and the commercial space small circular shell 5, the copper tube 9 passes through the commercial space small circular shell 5 and is connected to the pressure-sensing end of the capacitor 7, the commercial space small circular combination base 3 is made of PPS+glass fiber material wrapped SUS304 metal liner injection molding, the commercial space small circular combination base 3 is made of PPS composite reinforced material, the commercial space combination base metal inner shell 4 is cup-shaped, and has a stainless steel liner structure, which has both insulation performance and electromagnetic shielding function. Compared with the traditional structure, it reduces insulating paper, inner copper body, retaining ring and other components, and can realize automatic assembly. The O-ring inside the combination base adopts an insert design, and different depths of slots are used to adapt to pressure sensors of different ranges, and unified riveting parameters are used to optimize production management.

[0021] The working principle and usage process of a ceramic capacitive pressure sensor of the present invention are as follows: when the pressure of the measured fluid acts on the pressure-sensing end of the capacitor 7 through the copper tube 9, the capacitor 7 generates an electrical signal change due to deformation. After the signal is processed by the ASIC chip on the FPC flexible circuit board 6, it is transmitted to the external system through the terminal pin 2 and the electronic wire 11; the metal inner shell 4 of the commercial space combination base is embedded in the cup-shaped electromagnetic shielding structure formed by the commercial space small circular combination base 3, and the insulation properties of the PPS+glass fiber material are combined to achieve anti-interference and high pressure resistance functions. The sealing ring 8 ensures the structural sealing. When in use, first connect the copper tube 9 to the fluid pipeline, electrically connect the terminal pin 2 to the electronic wire 11 and check the sealing. After starting the system, the pressure signal is converted and output. The shielding structure continues to resist interference during operation. During maintenance, the sealing ring 8 can be checked and components can be replaced as needed. The integrated design of the combination base reduces traditional parts, and the maintenance efficiency is improved.

[0022] See Figure 8FIG. 1 is a control method for a ceramic capacitive pressure sensor according to an embodiment of the present invention, comprising: S1. Perform multi-frequency measurement on the capacitance of the pressure sensor in a pressure environment to be measured to obtain raw capacitance response data, and extract capacitance response features from the raw capacitance response data.

[0023] By extracting the capacitance response characteristics from the raw capacitance response data, the present invention can accurately reveal the patterns and trends of capacitance changes with pressure and frequency in the pressure sensor under actual pressure environments, providing a core basis for quantifying the pressure-capacitance relationship and evaluating sensor performance. This enables pressure detection to deeply reflect the dynamic response process of the sensor and improves the sensitivity of the detection results to actual pressure changes.

[0024] Among them, the pressure environment to be measured refers to the spatial environment in which the pressure sensor is located and the pressure needs to be measured, including various external pressure conditions that affect its capacitance change. For example, in the hydraulic system pipeline, different altitudes in the atmospheric environment, etc. all belong to the category of the pressure environment to be measured; the original capacitance response data refers to the capacitance value change data generated by the pressure sensor in the pressure environment to be measured due to the excitation signals of different frequencies during the multi-frequency measurement process, covering multi-dimensional information related to pressure, for example, under different frequency excitations such as 1kHz, 10kHz, and 100kHz, the capacitance value sequence output by the pressure sensor. These data provide a quantitative basis for analyzing the impact of pressure on capacitance. The capacitance response feature refers to the comprehensive analysis of the original capacitance response data. The various changing characteristics and laws of capacitance changes under the combined effects of pressure and frequency provide an overall summary of the capacitance response process. For example, the slope of the curve showing capacitance changes with pressure at different frequencies, the phase difference of capacitance changes, the amplitude ratio of capacitance changes under excitation at different frequencies, etc. These pieces of information reflecting the dynamic response process of capacitance constitute the capacitance response characteristics. Optionally, the multi-frequency measurement of the capacitance of the pressure sensor in the pressure environment to be measured can be achieved through a frequency synthesis and signal acquisition system, such as using a direct digital frequency synthesizer (DDS) to generate sinusoidal excitation signals of different frequencies, and using a high-precision capacitance-to-digital converter (CDC) to collect capacitance values ​​in real time, ultimately obtaining original capacitance response data containing capacitance changes at different frequencies.

[0025] As an embodiment of the present invention, extracting capacitance response features from the original capacitance response data includes: Analyzing the measurement frequency conditions corresponding to the original capacitance response data; Querying an initial capacitance value corresponding to the pressure sensor under the measurement frequency condition; Analyzing the capacitance-pressure sensitivity characteristic corresponding to the initial capacitance value; Based on the capacitance-pressure sensitivity characteristic, identifying capacitance frequency response data corresponding to the pressure sensor; Capacitance response features in the original capacitance response data are extracted based on the capacitance frequency response data.

[0026] Among them, the measurement frequency condition refers to the different excitation signal frequency parameter states used when starting to measure the capacitance of the pressure sensor, which is the starting excitation background of the capacitance response process. For example, the excitation signal frequency set before measurement is 5kHz, 50kHz, and 500kHz. These frequency parameters constitute the measurement frequency condition; the initial capacitance value refers to the capacitance value of the pressure sensor when it is not under pressure under the measurement frequency condition, reflecting the initial capacitance state of the sensor before detection. For example, under a certain set of frequency excitations, the initial capacitance value of the pressure sensor is 20pF. This value is an important basic data for subsequent analysis of capacitance changes; the capacitance-pressure sensitivity characteristic refers to the capacitance of the pressure sensor at a specific frequency. The sensitivity and variation pattern of capacitance value with pressure change, including sensitivity size, linearity and other characteristics. For example, at a frequency of 10kHz, the capacitance value increases by 0.5pF for every 1MPa increase in pressure. The relationship between pressure and capacitance change is the capacitance-pressure sensitivity characteristic; the capacitance frequency response data refers to the specific value and distribution of the capacitance value of the pressure sensor under different frequency excitations, reflecting the response difference of the capacitance to different frequency excitations. For example, after testing, under a pressure of 10kPa, the capacitance value of the pressure sensor is 22pF at 1kHz and 22.5pF at 10kHz. Recording the capacitance values ​​and differences at these different frequencies forms the capacitance frequency response data.

[0027] Furthermore, the analysis of the measurement frequency conditions corresponding to the original capacitance response data can be achieved through spectrum analysis technology, such as: using fast Fourier transform (FFT) combined with Python's NumPy library to perform spectrum decomposition on the original data, and finally obtaining frequency distribution data that characterizes the measurement frequency characteristics; the query of the initial capacitance value corresponding to the pressure sensor under the measurement frequency condition can be achieved through sensor calibration database retrieval technology, such as: using LabVIEW's database connection tool to call calibrated sensor parameter data, and finally obtaining the initial capacitance value that meets the current measurement frequency condition; the analysis of the capacitance-pressure sensitivity characteristics corresponding to the initial capacitance value can be achieved through regression analysis modeling technology, such as: using Origin software based on the least squares method to perform pressure-voltage regression modeling on the pressure sensor. The capacitance data is curve fitted to finally obtain a sensitivity characteristic curve describing the capacitance-pressure relationship; the identification of the capacitance frequency response data corresponding to the pressure sensor can be achieved through frequency sweep measurement and data processing technology, such as: using a network analyzer to perform wide-band frequency sweep measurement, and using MATLAB's signal processing toolbox to perform data filtering and feature extraction, and finally obtain data reflecting the capacitance frequency response characteristics; the extraction of capacitance response features from the original capacitance response data can be achieved through machine learning feature extraction technology, such as: using principal component analysis (PCA) in combination with the Scikit-learn library to perform dimensionality reduction processing on the data, extracting principal component features, and then using support vector machine (SVM) for feature screening, and finally obtain capacitance response features containing the frequency-pressure-capacitance relationship.

[0028] S2. Based on the capacitor response characteristics, analyze the dielectric gradient tensor and the plate deformation topology characteristics corresponding to the capacitor, determine the pressure tolerance threshold of the pressure environment to be measured, and calculate the coupling interference coefficients between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topology characteristics, respectively, to obtain the dielectric pressure drift coefficient and the deformation pressure drift coefficient.

[0029] Based on the capacitor response characteristics, the present invention analyzes the dielectric gradient tensor and plate deformation topological characteristics corresponding to the capacitor, which can provide an in-depth understanding of the physical change mechanism inside the pressure sensor and analyze the impact of pressure on the capacitor from the dual dimensions of dielectric properties and structural deformation, providing a theoretical basis for accurately evaluating sensor performance and optimizing design.

[0030] Among them, the dielectric gradient tensor is a mathematical quantity used to describe the spatial variation characteristics of the dielectric properties of the medium inside the pressure sensor under pressure. It reflects the gradient change of the dielectric constant inside the medium in different directions and positions, and reflects the medium polarization inhomogeneity caused by pressure. For example, under pressure, the dielectric constant of a certain area in the sensor medium changes at a rate of 0.2 along the x-axis and a rate of 0.1 along the y-axis. These change rates constitute the elements of the dielectric gradient tensor. The plate deformation topological characteristics refer to the topological characteristics presented by the changes in shape, size and surface morphology of the pressure sensor plate under pressure, covering the deformation mode, concave-convex distribution, crack propagation and other characteristics of the plate. Further, based on the capacitor response characteristics, the dielectric gradient tensor and the plate deformation topology characteristics corresponding to the capacitor are analyzed in combination with machine learning and multi-physics simulation technology. The capacitor response characteristics are extracted and pattern recognized by establishing a deep learning model. At the same time, multi-physics simulation software is used to simulate the changes in the dielectric properties of the sensor and the plate structure under pressure, so as to realize the combination of theoretical analysis and data-driven, and more accurately obtain the dielectric gradient tensor and the plate deformation topology characteristics.

[0031] The present invention calculates the coupling interference coefficients between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topological characteristics, respectively, to obtain the dielectric pressure drift coefficient and the deformation pressure drift coefficient. This can quantify the interaction between pressure and the sensor's dielectric properties and structural deformation, revealing the interference mechanism of pressure changes on capacitance measurement, and providing a key parameter for correcting measurement errors and improving measurement accuracy. The pressure tolerance threshold refers to the boundary value of the pressure variation range allowed in the measured pressure environment while ensuring the measurement accuracy and structural integrity of the pressure sensor. For example, if the measurement error of a pressure sensor does not exceed 2% and the plate has no obvious damage, its pressure tolerance threshold is 0-10 MPa, meaning that the sensor can operate normally within this pressure range. Furthermore, determining the pressure tolerance threshold for the measured pressure environment can be achieved through reliability testing and statistical analysis techniques. For example, by conducting multiple sets of long-term stability tests on the pressure sensor under different pressure conditions, collecting measurement data and structural state data, and analyzing the data using statistical methods such as Weibull distribution, the pressure tolerance threshold is ultimately determined.

[0032] As an embodiment of the present invention, respectively calculating the coupling interference coefficients between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topological characteristics to obtain the dielectric pressure drift coefficient and the deformation pressure drift coefficient includes: detecting a current pressure value corresponding to the dielectric gradient tensor and the plate deformation topological feature; Combining the current pressure value and the pressure tolerance threshold, the coupling interference coefficient between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topological characteristics is calculated using the following formula to obtain the dielectric pressure drift coefficient and the deformation pressure drift coefficient: ; ; Where A represents the dielectric pressure drift coefficient, represents the gradient minimum in the dielectric gradient tensor, represents the dielectric velocity tensor, Indicates the pressure tolerance threshold, E indicates the current pressure value, and B indicates the deformation pressure drift coefficient. represents the partial derivative of the plate deformation topological characteristics with respect to the pressure value, Represents the topological characteristics of plate deformation.

[0033] S3. Obtain the capacitance structure data and temperature compensation coefficient of the capacitor, combine the dielectric pressure drift coefficient, the deformation pressure drift coefficient and the capacitance structure data, construct a pressure response calibration matrix of the capacitor, generate an output drive instruction of the pressure sensor based on the pressure response calibration matrix, perform capacitance-voltage conversion of the capacitor according to the output drive instruction, and output the calibrated pressure measurement value.

[0034] The present invention obtains the capacitance structure data and temperature compensation coefficient of the capacitor, combines the dielectric pressure drift coefficient, the deformation pressure drift coefficient and the capacitance structure data, and constructs a pressure response calibration matrix of the capacitor. It can integrate the capacitor's own structural characteristics, the influence of ambient temperature and the dielectric and deformation drift factors caused by pressure, establish an accurate pressure-capacitance response correlation model, and provide a basis for accurate calibration of pressure measurement. Based on the pressure response calibration matrix, the output drive instruction of the pressure sensor is generated, and the capacitance-voltage conversion of the capacitor is performed according to the output drive instruction. The calibrated pressure measurement value is output, realizing a closed loop from the theoretical model to the actual measurement calibration, effectively eliminating multi-factor interference, and improving the measurement accuracy of the pressure sensor.

[0035] Among them, the capacitor structure data is a collection of information describing the physical structure and key parameters of the capacitor, covering the plate area, plate spacing, dielectric material properties (such as the initial value of the dielectric constant), etc., which is the basic basis for analyzing the pressure response characteristics of the capacitor. For example, the plate area of ​​a certain flat plate capacitor is (10mm^2) and the plate spacing is 2mm. These parameters constitute its capacitor structure data. The temperature compensation coefficient is a coefficient used to correct the influence of temperature change on capacitance measurement, reflecting the change in capacitance value or related electrical parameters when the temperature changes by 1 unit, because temperature will change the dielectric properties of the medium. , the physical size of the plate, etc., need to use this coefficient to compensate for the measurement error introduced by temperature. For example, the temperature compensation coefficient of a capacitor is (0.02pF / ℃), which means that the capacitance value theoretically changes by (0.02pF) for every increase in temperature (1℃). The pressure response calibration matrix is ​​a multidimensional matrix constructed by integrating the dielectric pressure drift coefficient, deformation pressure drift coefficient and capacitor structure data through a specific algorithm to correct the relationship between pressure and capacitance response. For example, the dielectric drift coefficient, plate deformation parameters and capacitor plate spacing under different pressures are decomposed and reconstructed into a tensor to form a The output drive instruction is a three-dimensional matrix containing correction weights for each parameter. The target pressure measurement requirement is converted into a signal instruction for controlling the capacitor-voltage conversion process based on the pressure response calibration matrix, covering control parameters such as conversion gain and compensation timing. For example, when the calibration matrix shows that the capacitor conversion gain needs to be amplified by 1.2 times to eliminate drift error under the current pressure, a control instruction including the gain parameter and the corresponding sampling frequency is generated to drive the capacitor-voltage conversion circuit to operate. Furthermore, the capacitor structure data and temperature compensation coefficient of the capacitor are obtained through an integrated sensor array and parameter calibration system. For example, after using a laser rangefinder to measure the plate spacing and a temperature and humidity sensor to collect environmental data, the corresponding temperature compensation coefficient is obtained in combination with a material calibration database. Based on the pressure response calibration matrix, a model predictive control algorithm is used to generate the output drive instruction of the pressure sensor in combination with the real-time pressure measurement requirement. For example, when the calibration matrix shows that there is a 0.5% drift error in the capacitance measurement under the current pressure, the algorithm calculates control parameters for adjusting the capacitor-voltage conversion gain to 1.05 times and increasing the sampling frequency by 20%, thereby generating the corresponding output drive instruction.

[0036] As an embodiment of the present invention, the step of combining the dielectric pressure drift coefficient, the deformation pressure drift coefficient, and the capacitor structure data to construct a pressure response calibration matrix of the capacitor includes: Performing multi-dimensional feature encoding on the capacitor structure data to obtain a structural feature quantum state; Performing physical field mapping processing on the dielectric pressure drift coefficient and the deformation pressure drift coefficient to obtain a drift coefficient distribution matrix; Performing a fusion calibration process on the structural characteristic quantum state and the drift coefficient distribution matrix to obtain a calibration primitive group; A tensor decomposition process is performed on the calibration primitive group to obtain a pressure response calibration matrix of the capacitor.

[0037] Among them, the structural characteristic quantum state is the quantum state form of the capacitor structure data converted into a multi-dimensional characteristic encoding with both parameter values ​​and related information (such as encoding parameters such as the plate spacing into a quantum superposition state); the drift coefficient distribution matrix is ​​the dielectric pressure drift coefficient and the deformation pressure drift coefficient converted into matrix data reflecting the spatial distribution law through physical field mapping processing (such as a matrix composed of drift coefficients of each region under simulated pressure); the calibration primitive group is the basic parameter combination required for the fusion calibration processing of the structural characteristic quantum state and the drift coefficient distribution matrix (such as a set including quantum correction terms and classical compensation coefficients).

[0038] Furthermore, the capacitance structure data can be multi-dimensionally encoded using a quantum entanglement coding algorithm to obtain a structural feature quantum state; the dielectric pressure drift coefficient and the deformation pressure drift coefficient can be physically mapped using a cellular automaton physical field simulation model to obtain a drift coefficient distribution matrix. For example, the dielectric drift coefficient matrix of the sensor core area under a pressure of 10 MPa can be obtained by simulation. , characterizes the drift differences at different locations; The structural characteristic quantum state and the drift coefficient distribution matrix can be fused and calibrated by a variational quantum-classical hybrid optimization algorithm to obtain a calibration primitive group. The structural characteristic quantum state is processed by a quantum processor, and the drift coefficient matrix is ​​optimized in combination with a classical algorithm to generate a calibration primitive containing quantum correction terms and classical compensation coefficients. For example, the calibration primitive group [0.3+0.2i,0.6] is obtained by a variational algorithm, and the quantum entanglement effect and the classical field distribution law are synchronously integrated. The calibration primitive group can be tensor-decomposed by a quantum tensor network decomposition technology to obtain the pressure response calibration matrix of the capacitor. The calibration primitive group is tensor-decomposed and reconstructed according to pressure, capacitor structure, and drift dimension. For example, Tucker decomposition is used to decompose the three-dimensional primitive group into a core tensor and a factor matrix, and the pressure response calibration matrix C containing the quantum-classical hybrid correction term is reconstructed to realize multi-physical field coupling calibration.

[0039] The present invention performs capacitance-voltage conversion of the capacitor according to the output drive instruction, and outputs a calibrated pressure measurement value, thereby effectively eliminating the influence of dielectric drift, deformation error and temperature interference on the measurement results, significantly improving the measurement accuracy and stability of the pressure sensor under complex working conditions, and providing reliable data support for scenarios such as industrial automation control and high-precision pressure monitoring. For example, in chemical pipeline pressure monitoring, production accidents and resource waste caused by measurement deviations can be avoided.

[0040] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A ceramic capacitive pressure sensor, comprising a packaging shell (10), characterized in that: The encapsulation shell (10) is provided with a small hollow circular shell (5), a copper tube (9) is provided on the side of the small hollow circular shell (5) away from the encapsulation shell (10), an electronic wire (11) is passed through the encapsulation shell (10), a small hollow combined base (3) is provided inside the small hollow circular shell (5), a metal inner shell (4) of the combined base (3) is provided inside the small hollow combined base (3), a capacitor (7) is provided inside the side of the small hollow combined base (3) close to the metal inner shell (4) of the combined base, an FPC flexible circuit board (6) is provided inside the encapsulation shell (10), and a small hollow terminal (1) is provided on the small hollow combined base (3).

2. A ceramic capacitive pressure sensor according to claim 1, characterized in that: The commercial air small circular terminal (1) is provided with a terminal pin (2), the package shell (10) is provided with an electronic wire (11), one end of the terminal pin (2) away from the commercial air small circular terminal (1) is connected to the electronic wire (11), and the commercial air combination base metal inner shell (4) is embedded in the commercial air small circular combination base (3), forming a cup-shaped electromagnetic shielding structure.

3. A ceramic capacitive pressure sensor as claimed in claim 2, characterized in that: The commercial hollow small circular terminal button (1) and the commercial hollow small circular combination base (3) are buckled together to form a whole, and the FPC flexible circuit board (6) is located inside.

4. The ceramic capacitive pressure sensor according to claim 1, wherein: One end of the terminal pin (2) close to the commercial small circular terminal (1) is electrically connected to the FPC flexible circuit board (6), and the FPC flexible circuit board (6) is electrically connected to the capacitor (7).

5. The ceramic capacitive pressure sensor according to claim 1, wherein: A sealing ring (8) is installed between the commercial air small circular assembly base (3) and the commercial air small circular shell (5), and the copper tube (9) passes through the commercial air small circular shell (5) and is connected to the pressure-sensing end of the capacitor (7).

6. The ceramic capacitive pressure sensor according to claim 1, wherein: The commercial space small circular combined base (3) is made of PPS composite reinforced material, and the commercial space combined base metal inner shell (4) is cup-shaped and has a stainless steel inner shell structure.

7. A control method for a ceramic capacitive pressure sensor, comprising: executing an application method of the ceramic capacitive pressure sensor according to any one of claims 1 to 6, characterized in that: The method comprises: Performing multi-frequency measurement on the capacitance of the pressure sensor in the pressure environment to be measured to obtain raw capacitance response data, and extracting capacitance response features from the raw capacitance response data; Based on the capacitance response characteristics, the dielectric gradient tensor and the plate deformation topology characteristics corresponding to the capacitance are analyzed to determine a pressure tolerance threshold of the pressure environment to be measured, and the coupling interference coefficients between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topology characteristics are calculated to obtain a dielectric pressure drift coefficient and a deformation pressure drift coefficient; Acquire the capacitance structure data and temperature compensation coefficient of the capacitor, combine the dielectric pressure drift coefficient, the deformation pressure drift coefficient and the capacitance structure data, construct a pressure response calibration matrix of the capacitor, generate an output drive instruction of the pressure sensor based on the pressure response calibration matrix, perform capacitance-voltage conversion of the capacitor according to the output drive instruction, and output a calibrated pressure measurement value.

8. The method according to claim 7, characterized in that The extracting capacitance response features from the original capacitance response data includes: Analyzing the measurement frequency conditions corresponding to the original capacitance response data; Querying an initial capacitance value corresponding to the pressure sensor under the measurement frequency condition; Analyzing the capacitance-pressure sensitivity characteristic corresponding to the initial capacitance value; Based on the capacitance-pressure sensitivity characteristic, identifying capacitance frequency response data corresponding to the pressure sensor; Capacitance response features in the original capacitance response data are extracted based on the capacitance frequency response data.

9. The method according to claim 7, characterized in that The step of respectively calculating the coupling interference coefficients between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topological characteristics to obtain a dielectric pressure drift coefficient and a deformation pressure drift coefficient includes: detecting a current pressure value corresponding to the dielectric gradient tensor and the plate deformation topological feature; Combining the current pressure value and the pressure tolerance threshold, the coupling interference coefficient between the pressure tolerance threshold and the dielectric gradient tensor and the plate deformation topological characteristics is calculated using the following formula to obtain the dielectric pressure drift coefficient and the deformation pressure drift coefficient: ； ； Where A represents the dielectric pressure drift coefficient, represents the gradient minimum in the dielectric gradient tensor, represents the dielectric velocity tensor, Indicates the pressure tolerance threshold, E indicates the current pressure value, and B indicates the deformation pressure drift coefficient. represents the partial derivative of the plate deformation topological characteristics with respect to the pressure value, Represents the topological characteristics of plate deformation.

10. The method according to claim 7, characterized in that The step of combining the dielectric pressure drift coefficient, the deformation pressure drift coefficient, and the capacitor structure data to construct a pressure response calibration matrix for the capacitor includes: Performing multi-dimensional feature encoding on the capacitor structure data to obtain a structural feature quantum state; Performing physical field mapping processing on the dielectric pressure drift coefficient and the deformation pressure drift coefficient to obtain a drift coefficient distribution matrix; Performing a fusion calibration process on the structural characteristic quantum state and the drift coefficient distribution matrix to obtain a calibration primitive group; A tensor decomposition process is performed on the calibration primitive group to obtain a pressure response calibration matrix of the capacitor.

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