A Structural Design Method and Device for a Brake Pressure Sensor

Abstract

The present invention relates to the technical field of pressure sensors, and discloses a structural design method and device for a brake pressure sensor, including: analyzing the material properties of the sensor material and the material requirements of the brake demand for the sensor material; calculating the material matching degree between the material properties and the material requirements, and determining the structural material for the brake application scenario from the sensor materials; querying the geometric parameters of the assembled sensor, and performing force-electricity simulation on the assembled sensor through the piezoelectric constitutive model; calculating the brake sensitivity of the assembled sensor by using the force-electricity simulation results, calculating the brake failure rate of the assembled sensor by using the force-electricity simulation results, and analyzing the defect causes of the brake sensitivity and the brake failure rate; querying the structural optimization material of the assembled sensor, and optimizing the structure of the assembled sensor by using the cause analysis results and the structural optimization material. The present invention can optimize the structural design and materials, and improve the sensitivity and environmental adaptability of the sensor.

Description

Technical Field

[0001] The present invention relates to a structural design method and device for a brake pressure sensor, belonging to the technical field of pressure sensors. Background Art

[0002] Existing piezoelectric sensor technologies have significant defects in terms of material properties, packaging design, manufacturing processes, and dynamic response, severely restricting their application in high-end brake systems. Firstly, when designing a brake pressure sensor using existing technologies, only the performance of the brake pressure sensor itself in braking is considered, without considering the matching with user requirements. Secondly, the mechanical stress distribution of existing pressure sensors is uneven, mainly manifested by the widespread phenomenon of stress concentration in the sensor structure, resulting in premature fatigue damage in local areas, affecting the uniformity of the electric field distribution, reducing signal accuracy, and the local stress > 50 MPa. Finally, existing technologies do not consider the mechanical-electrical coupling effect, and the simulation error > 20%.

[0003] This patent aims to solve the above problems and improve the sensitivity and environmental adaptability of the sensor by optimizing the structural design and materials. Summary of the Invention

[0004] The present invention provides a structural design method and device for a brake pressure sensor, whose main purpose is to optimize the structural design and materials, thereby improving the sensitivity and environmental adaptability of the sensor.

[0005] To achieve the above object, a structural design method for a brake pressure sensor provided by the present invention includes:

[0006] Query the brake application scenarios, analyze the brake requirements of the brake application scenarios, collect the sensor materials of the brake application scenarios, analyze the material properties of the sensor materials, and analyze the material requirements of the brake requirements with respect to the sensor materials;

[0007] Calculate the material matching degree between the material properties and the material requirements, and based on the material matching degree, determine the structural materials for the brake application scenarios from the sensor materials;

[0008] Perform material assembly on the structural materials to obtain an assembled sensor, query the geometric parameters of the assembled sensor, establish a piezoelectric constitutive model of the assembled sensor according to the geometric parameters, and perform mechanical-electrical simulation on the assembled sensor through the piezoelectric constitutive model to obtain a mechanical-electrical simulation result;

[0009] Calculate the braking sensitivity of the assembled sensor using the force-electricity simulation results, and calculate the braking failure rate of the assembled sensor using the force-electricity simulation results. Analyze the defect causes of the braking sensitivity and the braking failure rate to obtain a cause analysis result;

[0010] Based on the cause analysis result, query the structure optimization materials of the assembled sensor, and use the cause analysis result and the structure optimization materials to optimize the structure of the assembled sensor to obtain an optimized sensor, and use the optimized sensor as the sensor design result for the braking application scenario.

[0011] Optionally, analyzing the material properties of the sensor material includes: calculating the force-electricity conversion efficiency of the piezoelectric material in the sensor material;

[0012] Calculate the shear modulus of the elastomer material in the sensor material;

[0013] Calculate the conductivity of the electrode material in the sensor material;

[0014] Calculate the dielectric strength of the insulating material in the sensor material;

[0015] Calculate the thermal conductivity of the encapsulation material in the sensor material;

[0016] Calculate the carrier mobility of the signal processing circuit material in the sensor material;

[0017] Take the force-electricity conversion efficiency, the shear modulus, the conductivity, the dielectric strength, the thermal conductivity, and the carrier mobility as the material properties of the sensor material.

[0018] Optionally, analyzing the material requirements of the braking requirements for the sensor material includes:

[0019] Determine the numerical range of the preset material properties;

[0020] Classify the braking requirements of the same type in the braking requirements to obtain classified requirements;

[0021] Based on the classified requirements, classify the numerical range to obtain a classified range;

[0022] Take the intermediate value of the classified range as the material requirement of the classified requirement.

[0023] Optionally, calculating the material matching degree between the material properties and the material requirements includes:

[0024] Query the numerical bottom line and the numerical expectation in the material requirements;

[0025] Calculate the single - material matching degree between the material properties and the material requirements based on the numerical bottom line and the numerical expectation;

[0026] Obtain the performance weight of the material properties;

[0027] Use the performance weight to perform weighted summation on the single - material matching degree to obtain the material matching degree.

[0028] Optionally, the force - electricity simulation of the assembled sensor through the piezoelectric constitutive model to obtain the force - electricity simulation results includes:

[0029] Input the elastic constant, piezoelectric constant, and dielectric constant into the piezoelectric constitutive model to obtain the model to be solved;

[0030] Discretize the geometric model corresponding to the piezoelectric constitutive model into finite - element meshes;

[0031] Define the mechanical boundary conditions and electrical boundary conditions of the finite - element meshes;

[0032] According to the mechanical boundary conditions and the electrical boundary conditions, solve the model to be solved within the finite - element meshes to obtain the force - electricity simulation results;

[0033] Among them, the force - electricity simulation results include stress distribution and electric - field distribution.

[0034] Optionally, the calculation of the braking sensitivity of the assembled sensor using the force - electricity simulation results includes:

[0035] After installing the assembled sensor into a preset vehicle braking system, collect the instantaneous speed, rotation angle, and equivalent resistance of the vehicle braking system;

[0036] Calculate the braking sensitivity of the assembled sensor according to the instantaneous speed, the rotation angle, the equivalent resistance, and the force - electricity simulation results.

[0037] Optionally, the calculation of the braking failure rate of the assembled sensor using the force - electricity simulation results includes:

[0038] After installing the assembled sensor into a preset vehicle braking system, collect the braking force of the vehicle braking system;

[0039] Calculate the braking failure rate of the assembled sensor according to the braking force and the force - electricity simulation results.

[0040] Optionally, the defect - cause analysis of the braking sensitivity and the braking failure rate to obtain the cause - analysis result includes:

[0041] Determine whether the braking sensitivity is lower than a preset sensitivity threshold;

[0042] When the braking sensitivity is lower than the preset sensitivity threshold, obtain the electrode area, stress distribution, and electric field distribution corresponding to the braking sensitivity;

[0043] Select a first abnormal cause from the electrode area, the stress distribution, and the electric field distribution;

[0044] Determine whether the braking failure rate is higher than a preset failure rate threshold;

[0045] When the braking failure rate is lower than the preset failure rate threshold;

[0046] Obtain the parameter stability, stress distribution, and electric field distribution corresponding to the braking failure rate;

[0047] Select a second abnormal cause from the parameter stability, the stress distribution, and the electric field distribution;

[0048] Take the first abnormal cause and the second abnormal cause as the cause analysis results.

[0049] Optionally, the using the cause analysis results and the structure optimization material to perform structure optimization on the assembled sensor to obtain an optimized sensor includes:

[0050] After installing the structure optimization material in the assembled sensor, determine whether there is an electrode area, stress distribution, and electric field distribution in the cause analysis results;

[0051] When there is an electrode area in the cause analysis results, increase the current electrode area of the assembled sensor to obtain an increased electrode area;

[0052] When there is a stress distribution in the cause analysis results, disperse the stress receiving surface of the assembled sensor to obtain a dispersed receiving surface;

[0053] When there is an electric field distribution in the cause analysis results, optimize the electrode arrangement of the assembled sensor to obtain an optimized electrode arrangement;

[0054] Use the increased electrode area, the dispersed receiving surface, and the optimized electrode arrangement to determine the optimized sensor.

[0055] To solve the above problems, the present invention also provides a structural design device for a brake pressure sensor, and the device includes:

[0056] A requirements analysis module for querying brake application scenarios, analyzing the brake requirements of the brake application scenarios, collecting the sensor materials of the brake application scenarios, analyzing the material properties of the sensor materials, and analyzing the material requirements of the brake requirements with respect to the sensor materials;

[0057] A material determination module for calculating the material matching degree between the material properties and the material requirements, and based on the material matching degree, determining the structural material of the brake application scenario from the sensor materials;

[0058] A sensor simulation module for assembling the structural materials to obtain an assembled sensor, querying the geometric parameters of the assembled sensor, establishing a piezoelectric constitutive model of the assembled sensor according to the geometric parameters, and performing force-electricity simulation on the assembled sensor through the piezoelectric constitutive model to obtain a force-electricity simulation result;

[0059] A cause analysis module for calculating the brake sensitivity of the assembled sensor by using the force-electricity simulation result, calculating the brake failure rate of the assembled sensor by using the force-electricity simulation result, and performing defect cause analysis on the brake sensitivity and the brake failure rate to obtain a cause analysis result;

[0060] A sensor design module for querying the structural optimization materials of the assembled sensor based on the cause analysis result, optimizing the structure of the assembled sensor by using the cause analysis result and the structural optimization materials to obtain an optimized sensor, and taking the optimized sensor as the sensor design result of the brake application scenario.

[0061] Compared with the problems described in the background art, in the embodiments of the present invention, by analyzing the material properties of the sensor material to analyze the characteristics of the material itself and the characteristics after being subjected to external stress, and by analyzing the braking requirements regarding the material requirements of the sensor material to analyze the requirements of the actual application scenario for the sensor material, a foundation is laid for calculating the matching degree between the sensor material and the actual requirements in the subsequent steps. In the embodiments of the present invention, by calculating the material matching degree between the material properties and the material requirements, materials are selected based on the material matching degree, thereby improving the environmental adaptability of the sensor material. Further, in the embodiments of the present invention, force-electricity simulation is performed on the assembled sensor through the piezoelectric constitutive model, and based on the multi-field coupling simulation platform, a full-condition performance prediction model of the sensor is established. The actual test and simulation error is <3%, significantly improving the design reliability. And through finite element simulation, the stress distribution and electric field distribution are analyzed. In the embodiments of the present invention, by using the force-electricity simulation results to calculate the braking sensitivity of the assembled sensor, based on the relationship between the stress distribution, electric field distribution and sensitivity, it is judged whether the stress distribution and electric field distribution need to be optimized through the performance of the sensitivity, so as to optimize the structure affecting the stress distribution and electric field distribution in the subsequent steps, and at the same time improve the sensitivity of the sensor structure. Further, in the embodiments of the present invention, by using the force-electricity simulation results to calculate the braking failure rate of the assembled sensor, based on the relationship between the stress distribution, electric field distribution and failure rate, it is judged whether the stress distribution and electric field distribution need to be optimized through the performance of the failure rate, so as to optimize the structure affecting the stress distribution and electric field distribution in the subsequent steps, and at the same time reduce the failure rate of the sensor structure. Further, in the embodiments of the present invention, by using the cause analysis results and the structure optimization materials to optimize the structure of the assembled sensor, the structure design and materials are optimized, thereby improving the sensitivity and environmental adaptability of the sensor. Therefore, the structure design method and device for a brake pressure sensor provided by the embodiments of the present invention can optimize the structure design and materials, and thereby improve the sensitivity and environmental adaptability of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic flowchart of a structure design method for a brake pressure sensor provided by an embodiment of the present invention;

[0063] Figure 2 It is a schematic diagram of modules for implementing the structure design device for a brake pressure sensor provided by an embodiment of the present invention.

[0064] The implementation, functional features and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0065] It should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0066] An embodiment of the present application provides a structural design method for a brake pressure sensor. The execution subject of the structural design method for the brake pressure sensor includes, but is not limited to, at least one of electronic devices such as a server, a terminal, etc. that can be configured to execute the method provided by the embodiment of the present application. In other words, the structural design method for the brake pressure sensor can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to: a single server, a server cluster, a cloud server, or a cloud server cluster, etc.

[0067] Embodiment 1:

[0068] Refer to Figure 1 As shown, it is a flowchart of a structural design method for a brake pressure sensor provided by an embodiment of the present invention. In this embodiment, the structural design method for the brake pressure sensor includes:

[0069] S1. Query the brake application scenario, analyze the brake requirements of the brake application scenario, collect the sensor materials of the brake application scenario, analyze the material properties of the sensor materials, and analyze the material requirements of the brake requirements with respect to the sensor materials.

[0070] In an embodiment of the present invention, the brake application scenario refers to a scenario where the vehicle to which the brake pressure sensor is applied will brake, such as a braking scenario when a small car is driving at a medium or low speed in the city, or a braking scenario when a large truck is driving fast on the highway. Further, the brake requirement refers to the requirement for the performance of the brake in the brake application scenario. For example, in the braking scenario when a small car is driving at a medium or low speed in the city, the brake requirement is that the braking ability is medium. In the braking scenario when a large truck is driving fast on the highway, the brake requirement is that the braking ability is extremely high. The braking ability herein refers to the ability to evaluate the quality of the brake pressure sensor, such as the accuracy of monitoring pressure of the brake pressure sensor, the reaction speed of responding to the brake, wear resistance and corrosion resistance, temperature stability, anti-electromagnetic interference, mechanical strength, waterproofness, and dustproofness. The sensor material refers to the components required to construct a complete piezoelectric sensor, such as piezoelectric material, elastomer material, electrode material, insulating material, packaging material, signal processing circuit material, etc. The piezoelectric material is responsible for converting mechanical energy into electrical energy. The elastomer material transmits pressure and protects the piezoelectric material. The electrode material collects the charges generated by the piezoelectric material (the piezoelectric material has a crystal structure, and the crystal structure changes under external pressure to generate positive and negative charges). The insulating material isolates the electrodes to prevent short circuits. The packaging material protects the internal components, preventing dust, moisture, and mechanical damage. The signal processing circuit material amplifies and processes the piezoelectric signal.

[0071] Further, in the embodiments of the present invention, the material properties of the sensor material are analyzed to analyze the characteristics of the material itself and the characteristics after being subjected to external stress.

[0072] In one embodiment of the present invention, the analysis of the material properties of the sensor material includes: calculating the force-electric conversion efficiency of the piezoelectric material in the sensor material by using the following formula:

[0073] ;

[0074] where, represents the force-electric conversion efficiency, represents the piezoelectric coefficient, represents the strain of the piezoelectric material, represents the magnitude of the stress applied to the piezoelectric material, represents the dielectric constant, represents the transpose symbol;

[0075] calculating the shear modulus of the elastomer material in the sensor material by using the following formula:

[0076] ;

[0077] where, represents the shear modulus, represents the shear stress, represents the dimensionless shear strain;

[0078] calculating the conductivity of the electrode material in the sensor material by using the following formula:

[0079] ;

[0080] where, represents the conductivity, represents the current density, represents the electric field strength;

[0081] calculating the dielectric strength of the insulating material in the sensor material by using the following formula: ;

[0082] where, represents the dielectric strength, represents the breakdown voltage, represents the thickness of the insulating material;

[0083] calculating the thermal conductivity of the encapsulation material in the sensor material by using the following formula: ;

[0084] where, represents the thermal conductivity, represents the heat flux, represents the thickness of the encapsulating material, represents the heated area, represents the temperature difference on the surface of the encapsulating material;

[0085] The carrier mobility of the signal processing circuit material in the sensor material is calculated using the following formula: ;

[0086] where, represents the carrier mobility, represents the carrier velocity, represents the electric field strength on the signal processing circuit material;

[0087] The force - electricity conversion efficiency, the shear modulus, the conductivity, the dielectric strength, the thermal conductivity, and the carrier mobility are taken as the material properties of the sensor material.

[0088] Further, in an embodiment of the present invention, the material requirements refer to the requirements for each material under the braking requirements. For example, when the braking requirement is extremely high braking ability, the requirement for the force - electricity conversion efficiency of the piezoelectric material is relatively high.

[0089] Further, the embodiment of the present invention analyzes the material requirements of the sensor material regarding the braking requirements to analyze the requirements of the actual application scenario for the sensor material, laying a foundation for subsequent calculation of the matching degree between the sensor material and the actual requirements.

[0090] In an embodiment of the present invention, the analysis of the material requirements of the sensor material regarding the braking requirements includes: determining the numerical range of the preset material properties; classifying the same type of braking requirements in the braking requirements to obtain classified requirements; based on the classified requirements, classifying the numerical range to obtain classified ranges; taking the intermediate value of the classified ranges as the material requirements of the classified requirements.

[0091] Among them, the material properties include piezoelectric conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity, and carrier mobility. The numerical range refers to the numerical range between the lower limit and the upper limit of the material property. Since the braking requirements are the requirements for piezoelectric conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity, and carrier mobility respectively, the classification requirements refer to the numerical grades obtained by classifying the numerical values of any one of the piezoelectric conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity, and carrier mobility. For example, if the material requirement has a high requirement for the piezoelectric conversion efficiency of the piezoelectric material, the classification requirement is a high-grade requirement; if the material requirement has a low requirement for the piezoelectric conversion efficiency of the piezoelectric material, the classification requirement is a low-grade requirement. When the total number of grade types in the classification requirements is low, medium, etc., and the total number of grade types in the classification requirements is 3, the numerical range is evenly divided into 3 intervals from small to large, and these three intervals are the classification intervals.

[0092] S2. Calculate the material matching degree between the material performance and the material requirement, and based on the material matching degree, determine the structural material for the braking application scenario from the sensor materials.

[0093] In the embodiment of the present invention, by calculating the material matching degree between the material performance and the material requirement, materials are selected based on the material matching degree, thereby improving the environmental adaptability of the sensor materials.

[0094] In an embodiment of the present invention, calculating the material matching degree between the material performance and the material requirement includes: querying the numerical bottom line and numerical expectation in the material requirement; based on the numerical bottom line and the numerical expectation, using the following formula to calculate the single-material matching degree between the material performance and the material requirement:

[0095] ;

[0096] Among them, represents the single-material matching degree, represents the th numerical value of the material performance, represents the th numerical expectation of the material requirement, represents the th numerical bottom line of the material requirement;

[0097] Obtain the performance weight of the material performance; use the performance weight to perform weighted summation on the single-material matching degree to obtain the material matching degree.

[0098] Among them, the numerical bottom line refers to the worst value of each type of numerical value in the material requirements. For example, when the material requirement is the requirement for the force-electric conversion efficiency of a piezoelectric material, the greater the force-electric conversion efficiency value, the better the sensor material. Then, the large value (upper limit) is used as the numerical expectation, and the small value (lower limit) is used as the numerical bottom line. When selecting the numerical bottom line and the numerical expectation, it is necessary to determine according to the actual scenario's requirements for the numerical value. For example, in the scenario of a large truck, the numerical bottom line is set as a, and the numerical expectation is set as b. Further, since the material properties include force-electric conversion efficiency, shear modulus, conductivity, dielectric strength, thermal conductivity, and carrier mobility, the weight of each type of property among force-electric conversion efficiency, shear modulus, conductivity, dielectric strength, thermal conductivity, and carrier mobility is different, and the performance weight is generally determined based on past experience. For example, the thermal conductivity weight is 0.4, and the shear modulus weight is 0.3.

[0099] Optionally, the process of determining the structural material for the brake application scenario from the sensor materials based on the material matching degree means: selecting the material combination with the highest material matching degree as the structural material. It should be noted that each material has multiple candidate materials. For example, for piezoelectric materials, the candidate materials include quartz, piezoelectric ceramics (PZT), polyvinylidene fluoride (PVDF), etc.

[0100] S3. Perform material assembly on the structural material to obtain an assembled sensor. Query the geometric parameters of the assembled sensor. According to the geometric parameters, establish a piezoelectric constitutive model of the assembled sensor. Through the piezoelectric constitutive model, perform force-electricity simulation on the assembled sensor to obtain a force-electricity simulation result.

[0101] Optionally, the process of performing material assembly on the structural material to obtain an assembled sensor refers to the process of combining materials according to past experience. The piezoelectric conversion part of the assembled sensor adopts a sandwich structure, which mainly includes piezoelectric materials, elastomeric materials, electrode materials, insulating materials, and packaging materials. In addition to the piezoelectric conversion part, the assembled sensor also includes a signal processing circuit, which is mainly composed of signal processing circuit materials, and the signal processing circuit is a conventional circuit.

[0102] In an embodiment of the present invention, establishing the piezoelectric constitutive model of the assembled sensor according to the geometric parameters includes: establishing a geometric model of the assembled sensor according to the geometric parameters; wherein, the geometric model includes a piezoelectric material layer, electrodes, and a support structure; establishing a piezoelectric constitutive equation of the geometric model; and using the piezoelectric constitutive equation as the piezoelectric constitutive model of the assembled sensor.

[0103] Among them, the support structure, such as a base, is used to support the assembled sensor so that the assembled sensor is placed three-dimensionally. The piezoelectric constitutive equation mainly describes the relationship between its stress-strain relationship and the electric field, and usually includes parameters such as stress, strain, electric field strength, and nonlinear constants, and is used to describe the characteristics of piezoelectric materials under the action of external forces and electric fields.

[0104] Furthermore, in the embodiment of the present invention, force-electricity simulation is performed on the assembled sensor through the piezoelectric constitutive model to establish a full-condition performance prediction model of the sensor based on a multi-field coupling simulation platform. The actual test and simulation error is <3%, significantly improving the design reliability, and the stress distribution and electric field distribution are analyzed through finite element simulation.

[0105] In an embodiment of the present invention, performing force-electricity simulation on the assembled sensor through the piezoelectric constitutive model to obtain a force-electricity simulation result includes: inputting elastic constants, piezoelectric constants, and dielectric constants into the piezoelectric constitutive model to obtain a model to be solved; discretizing the geometric model corresponding to the piezoelectric constitutive model into finite element meshes; defining mechanical boundary conditions and electrical boundary conditions for the finite element meshes; solving the model to be solved within the finite element meshes according to the mechanical boundary conditions and the electrical boundary conditions to obtain a force-electricity simulation result; wherein, the force-electricity simulation result includes stress distribution and electric field distribution.

[0106] Among them, the elastic constants, piezoelectric constants, and dielectric constants are specific numerical values corresponding to the parameters in the piezoelectric constitutive model. The model to be solved refers to the piezoelectric constitutive model for which stress distribution and electric field distribution are to be solved through finite element analysis software. The mechanical boundary conditions and electrical boundary conditions refer to the conditions on the defined geometric model boundary to simulate the boundary behavior in a real system. These conditions can be displacement, force, pressure, temperature, etc., corresponding to the constraints or external loads in a real system.

[0107] Optionally, solving the model to be solved within the finite element meshes to obtain a force-electricity simulation result refers to the process of solving the stress distribution and electric field distribution in each finite element mesh through finite element analysis software.

[0108] S4. Calculate the braking sensitivity of the assembled sensor using the force-electricity simulation result, and calculate the braking failure rate of the assembled sensor using the force-electricity simulation result, and perform defect cause analysis on the braking sensitivity and the braking failure rate to obtain a cause analysis result.

[0109] In an embodiment of the present invention, the braking sensitivity of the assembled sensor is calculated by using the force-electricity simulation result. Based on the relationship between the stress distribution, the electric field distribution, and the sensitivity, it is determined whether the stress distribution and the electric field distribution need to be optimized through the performance of the sensitivity, so as to optimize the structure affecting the stress distribution and the electric field distribution subsequently, and at the same time improve the sensitivity of the sensor structure.

[0110] Among them, the braking sensitivity refers to the sensitivity of the electrical output of the piezoelectric sensor under the action of the braking pressure in the performance of the dynamic characteristics of the braking system.

[0111] In an embodiment of the present invention, the calculation of the braking sensitivity of the assembled sensor by using the force-electricity simulation result includes: after installing the assembled sensor into a preset vehicle braking system, collecting the instantaneous speed, the rotation angle, and the equivalent resistance of the vehicle braking system; according to the instantaneous speed, the rotation angle, the equivalent resistance, and the force-electricity simulation result, calculating the braking sensitivity of the assembled sensor by using the following formula:

[0112] ;

[0113] Among them, represents the braking sensitivity, represents the piezoelectric coefficient, represents the stress distribution at the coordinate position in the force-electricity simulation result, represents the electric field distribution at the coordinate position in the force-electricity simulation result, represents the electrical quality factor of the piezoelectric material, represents the interval of the X-axis occupied by the electrodes in the assembled sensor, represents the axis occupied by the electrodes in the assembled sensor, represents the instantaneous speed, represents the rotation angle, represents the equivalent resistance, represents the time interval for the vehicle braking system to brake, represents the time variable, represents the tensor subscript, represents the X-axis, represents the Y direction.

[0114] Among them, the automotive braking system refers to a series of special devices that apply a certain force to some parts of the vehicle (mainly the wheels) to forcibly brake them to a certain extent, such as the brake disc. The instantaneous speed, the rotation angle, and the equivalent resistance mainly come from the brake disc, and the equivalent resistance includes friction and air resistance.

[0115] Further, in the embodiment of the present invention, the braking failure rate of the assembled sensor is calculated by using the force-electricity simulation result, so as to judge whether it is necessary to optimize the stress distribution and the electric field distribution based on the relationship between the stress distribution, the electric field distribution and the failure rate, and then optimize the structure affecting the stress distribution and the electric field distribution in the subsequent process, while reducing the failure rate of the sensor structure.

[0116] Wherein, the braking failure rate refers to the failure risk of the dynamic characteristics of the braking system caused by stress overrun and electric field abnormality during the braking process of the piezoelectric sensor.

[0117] In one embodiment of the present invention, the calculating the braking failure rate of the assembled sensor by using the force-electricity simulation result includes: after installing the assembled sensor into a preset vehicle braking system, collecting the braking force of the vehicle braking system; and calculating the braking failure rate of the assembled sensor by using the following formula according to the braking force and the force-electricity simulation result:

[0118] ;

[0119] Wherein, represents the braking failure rate, represents the stress distribution at the moment in the force-electricity simulation result, represents the preset stress threshold, represents the electric field distribution at the moment in the force-electricity simulation result, represents the preset electric field threshold, represents the constant of electric field abnormality, represents the electrical quality factor of the piezoelectric material at the moment represents the time variable, represents the tensor subscript, represents the X-axis, represents the Y direction, represents the equivalent resistance, represents the braking force at the moment represents the mean value of represents the variance of represents the interval on the X-axis occupied by the electrodes in the assembled sensor, represents the interval on the

[0120] Wherein, the braking force refers to the maximum rolling friction force that can be achieved, also known as the braking force.

[0121] In one embodiment of the present invention, the defect cause analysis of the brake sensitivity and the brake failure rate is performed to obtain a cause analysis result, including: determining whether the brake sensitivity is lower than a preset sensitivity threshold; when the brake sensitivity is lower than the preset sensitivity threshold, obtaining the electrode area, stress distribution, and electric field distribution corresponding to the brake sensitivity; selecting a first abnormal cause from the electrode area, the stress distribution, and the electric field distribution; determining whether the brake failure rate is higher than a preset failure rate threshold; when the brake failure rate is lower than the preset failure rate threshold; obtaining the parameter stability, stress distribution, and electric field distribution corresponding to the brake failure rate; selecting a second abnormal cause from the parameter stability, the stress distribution, and the electric field distribution; and taking the first abnormal cause and the second abnormal cause as the cause analysis result.

[0122] Among them, the preset sensitivity threshold and the preset failure rate threshold need to be set according to the actual scenario, mainly for screening low sensitivity and high failure rate. The electrode area refers to the area occupied by the electrode calculated from the X-axis interval and the Y-axis interval The first abnormal cause refers to a parameter that exceeds the normal value range. For example, if the electrode area exceeds the normal range, the electrode area is taken as the first abnormal cause. Parameter stability refers to the property of whether a parameter affected by temperature is stable. For example, the electrical quality factor has temperature stability and will change under the influence of temperature. The meaning of the second abnormal cause is the same as that of the first abnormal cause.

[0123] S5. Based on the cause analysis result, query the structure optimization materials of the assembled sensor, and use the cause analysis result and the structure optimization materials to optimize the structure of the assembled sensor to obtain an optimized sensor, and take the optimized sensor as the sensor design result for the brake application scenario.

[0124] Among them, the structure optimization materials include a shielding layer material, a temperature compensation circuit material, and a filtering circuit material. The shielding layer material is used to shield the interference of the external electric field and improve the uniformity of the electric field distribution of the sensor. The temperature compensation circuit material is used to ensure the temperature stability of the material performance. The filtering circuit material is used to increase the electric field strength of the electric field distribution, thereby enhancing the electric signal output by the sensor.

[0125] Furthermore, in the embodiment of the present invention, the structure of the assembled sensor is optimized by using the cause analysis result and the structure optimization materials to optimize the structure design and materials, thereby improving the sensitivity and environmental adaptability of the sensor.

[0126] In one embodiment of the present invention, the structural optimization of the assembled sensor by using the cause analysis result and the structural optimization material to obtain an optimized sensor includes: after installing the structural optimization material in the assembled sensor, determining whether there are electrode area, stress distribution, and electric field distribution in the cause analysis result; when there is an electrode area in the cause analysis result, increasing the current electrode area of the assembled sensor to obtain an increased electrode area; when there is a stress distribution in the cause analysis result, dispersing the stress receiving surface of the assembled sensor to obtain a dispersed receiving surface; when there is an electric field distribution in the cause analysis result, optimizing the electrode arrangement of the assembled sensor to obtain an optimized electrode arrangement; and determining the optimized sensor by using the increased electrode area, the dispersed receiving surface, and the optimized electrode arrangement.

[0127] Optionally, the process of increasing the current electrode area of the assembled sensor refers to a process of increasing in small amounts multiple times. For example, if the total area is 10, the area size is increased by 0.5 each time, and then the process of calculating the sensitivity and failure rate is returned. It is analyzed whether the increased area can make the sensitivity and failure rate parameters normal. Further, the process of dispersing the stress receiving surface of the assembled sensor refers to dispersedly installing the material for receiving external pressure of the assembled sensor. For example, an appropriate distance is increased between each piece of material so that the materials are not too concentrated. The dispersion distance is also a process of increasing in small amounts multiple times. Further, the process of optimizing the electrode arrangement of the assembled sensor is to optimize the shape of the electrode distribution, thereby increasing the uniformity of the electric field distribution. For example, the electrode is adjusted to a row electrode shape, a multi-layer / three-dimensional electrode shape, etc.

[0128] Compared with the problems described in the background art, in the embodiments of the present invention, the material properties of the sensor material are analyzed to analyze the characteristics of the material itself and the characteristics after being subjected to external stress. In the embodiments of the present invention, the braking requirements are analyzed in terms of the material requirements of the sensor material to analyze the requirements of the actual application scenario for the sensor material, laying a foundation for calculating the matching degree between the sensor material and the actual requirements. In the embodiments of the present invention, the material matching degree between the material properties and the material requirements is calculated to select materials based on the material matching degree, thereby improving the environmental adaptability of the sensor material. Further, in the embodiments of the present invention, force-electricity simulation is performed on the assembled sensor through the piezoelectric constitutive model, and a full-condition performance prediction model of the sensor is established based on the multi-field coupling simulation platform. The actual test and simulation error is <3%, significantly improving the design reliability. The stress distribution and electric field distribution are analyzed through finite element simulation. In the embodiments of the present invention, the braking sensitivity of the assembled sensor is calculated by using the force-electricity simulation results. Based on the relationship between the stress distribution, electric field distribution and sensitivity, it is judged whether the stress distribution and electric field distribution need to be optimized through the performance of the sensitivity, so as to optimize the structure affecting the stress distribution and electric field distribution in the subsequent process, and at the same time improve the sensitivity of the sensor structure. Further, in the embodiments of the present invention, the braking failure rate of the assembled sensor is calculated by using the force-electricity simulation results. Based on the relationship between the stress distribution, electric field distribution and failure rate, it is judged whether the stress distribution and electric field distribution need to be optimized through the performance of the failure rate, so as to optimize the structure affecting the stress distribution and electric field distribution in the subsequent process, and at the same time reduce the failure rate of the sensor structure. Further, in the embodiments of the present invention, the assembled sensor is structurally optimized by using the cause analysis result and the structure optimization material to optimize the structure design and material, thereby improving the sensitivity and environmental adaptability of the sensor. Therefore, the structure design method and device for a brake pressure sensor provided by the embodiments of the present invention can optimize the structure design and material, thereby improving the sensitivity and environmental adaptability of the sensor.

[0129] Embodiment 2:

[0130] As Figure 2 shown, it is a functional module diagram of a structure design device for a brake pressure sensor according to the present invention.

[0131] The structural design device 200 for a brake pressure sensor according to the present invention can be installed in an electronic device. According to the functions achieved, the structural design device for a brake pressure sensor may include a requirements analysis module 201, a material determination module 202, a sensor simulation module 203, a cause analysis module 204, and a sensor design module 205. The modules in the present invention may also be referred to as units, which refer to a series of computer program segments that can be executed by a processor of an electronic device and can complete fixed functions, and are stored in the memory of the electronic device.

[0132] In the embodiments of the present invention, the functions of each module / unit are as follows:

[0133] The requirements analysis module 201 is used to query the brake application scenarios, analyze the brake requirements of the brake application scenarios, collect the sensor materials of the brake application scenarios, analyze the material properties of the sensor materials, and analyze the material requirements of the brake requirements for the sensor materials;

[0134] The material determination module 202 is used to calculate the material matching degree between the material properties and the material requirements, and based on the material matching degree, determine the structural material for the brake application scenarios from the sensor materials;

[0135] The sensor simulation module 203 is used to assemble the structural materials to obtain an assembled sensor, query the geometric parameters of the assembled sensor, establish a piezoelectric constitutive model of the assembled sensor according to the geometric parameters, and perform force-electricity simulation on the assembled sensor through the piezoelectric constitutive model to obtain a force-electricity simulation result;

[0136] The cause analysis module 204 is used to calculate the brake sensitivity of the assembled sensor by using the force-electricity simulation result, calculate the brake failure rate of the assembled sensor by using the force-electricity simulation result, perform defect cause analysis on the brake sensitivity and the brake failure rate, and obtain a cause analysis result;

[0137] The sensor design module 205 is used to query the structural optimization materials of the assembled sensor based on the cause analysis result, optimize the structure of the assembled sensor by using the cause analysis result and the structural optimization materials to obtain an optimized sensor, and use the optimized sensor as the sensor design result for the brake application scenarios.

[0138] Specifically, each module in the structural design device 200 for a brake pressure sensor in the embodiments of the present invention adopts the same as the above-mentioned Figure 1The same technical means as those described in the structural design method applied to the brake pressure sensor are adopted and can produce the same technical effects, which will not be elaborated here.

[0139] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A structural design method applied to a brake pressure sensor, characterized in that, The method includes: Querying the brake application scenario, analyzing the brake requirements of the brake application scenario, collecting the sensor materials of the brake application scenario, analyzing the material properties of the sensor materials, and analyzing the material requirements of the brake requirements with respect to the sensor materials, wherein the analysis of the material requirements of the brake requirements with respect to the sensor materials includes: Determining the numerical range of the preset material properties; Classifying the same type of brake requirements in the brake requirements to obtain classified requirements; Based on the classified requirements, classifying the numerical range to obtain classified ranges; Taking the intermediate value of the classified range as the material requirement of the classified requirement; Calculating the material matching degree between the material properties and the material requirements, and determining the structural material of the brake application scenario from the sensor materials based on the material matching degree; Performing material assembly on the structural material to obtain an assembled sensor, querying the geometric parameters of the assembled sensor, establishing a piezoelectric constitutive model of the assembled sensor according to the geometric parameters, and performing force-electricity simulation on the assembled sensor through the piezoelectric constitutive model to obtain a force-electricity simulation result, wherein the performing force-electricity simulation on the assembled sensor through the piezoelectric constitutive model to obtain a force-electricity simulation result includes: Inputting the elastic constant, piezoelectric constant and dielectric constant into the piezoelectric constitutive model to obtain a model to be solved; Discretizing the geometric model corresponding to the piezoelectric constitutive model into finite element meshes; Defining the mechanical boundary conditions and electrical boundary conditions of the finite element meshes; Solving the model to be solved in the finite element meshes according to the mechanical boundary conditions and the electrical boundary conditions to obtain a force-electricity simulation result; Wherein the force-electricity simulation result includes stress distribution and electric field distribution; Calculating the brake sensitivity of the assembled sensor by using the force-electricity simulation result, and calculating the brake failure rate of the assembled sensor by using the force-electricity simulation result, and performing defect cause analysis on the brake sensitivity and the brake failure rate to obtain a cause analysis result; Based on the cause analysis result, querying the structural optimization materials of the assembled sensor, and performing structural optimization on the assembled sensor by using the cause analysis result and the structural optimization materials to obtain an optimized sensor, and taking the optimized sensor as the sensor design result of the brake application scenario.

2. The structural design method applied to a brake pressure sensor according to claim 1, characterized in that, The analysis of the material properties of the sensor materials includes: calculating the force-electric conversion efficiency of the piezoelectric material in the sensor materials; Calculating the shear modulus of the elastomer material in the sensor materials; Calculating the conductivity of the electrode material in the sensor materials; Calculating the dielectric strength of the insulating material in the sensor materials; Calculating the thermal conductivity of the packaging material in the sensor materials; Calculating the carrier mobility of the signal processing circuit material in the sensor materials; Taking the force-electric conversion efficiency, the shear modulus, the conductivity, the dielectric strength, the thermal conductivity and the carrier mobility as the material properties of the sensor materials.

3. The structural design method applied to a brake pressure sensor according to claim 1, characterized in that, Calculating the material matching degree between the material properties and the material requirements includes: Querying the numerical bottom line and numerical expectation in the material requirements; Calculating the single-material matching degree between the material properties and the material requirements based on the numerical bottom line and the numerical expectation; Obtaining the performance weight of the material properties; Performing weighted summation on the single-material matching degree using the performance weight to obtain the material matching degree.

4. The structural design method applied to a brake pressure sensor according to claim 1, characterized in that Calculating the braking sensitivity of the assembled sensor using the force and electricity simulation results includes: After installing the assembled sensor into a preset vehicle braking system, collecting the instantaneous speed, rotation angle, and equivalent resistance of the vehicle braking system; Calculating the braking sensitivity of the assembled sensor according to the instantaneous speed, the rotation angle, the equivalent resistance, and the force and electricity simulation results.

5. The structural design method applied to a brake pressure sensor according to claim 1, characterized in that Calculating the braking failure rate of the assembled sensor using the force and electricity simulation results includes: After installing the assembled sensor into a preset vehicle braking system, collecting the braking force of the vehicle braking system; Calculating the braking failure rate of the assembled sensor according to the braking force and the force and electricity simulation results.

6. The structural design method applied to a brake pressure sensor according to claim 1, characterized in that, Performing defect cause analysis on the braking sensitivity and the braking failure rate to obtain a cause analysis result includes: Judging whether the braking sensitivity is lower than a preset sensitivity threshold; When the braking sensitivity is lower than the preset sensitivity threshold, obtaining the electrode area, stress distribution, and electric field distribution corresponding to the braking sensitivity; Selecting a first abnormal cause from the electrode area, the stress distribution, and the electric field distribution; Judging whether the braking failure rate is higher than a preset failure rate threshold; When the braking failure rate is higher than the preset failure rate threshold; Obtaining the parameter stability, stress distribution, and electric field distribution corresponding to the braking failure rate; Selecting a second abnormal cause from the parameter stability, the stress distribution, and the electric field distribution; Taking the first abnormal cause and the second abnormal cause as the cause analysis result.

7. The structural design method applied to a brake pressure sensor according to claim 1, characterized in that, Performing structural optimization on the assembled sensor using the cause analysis result and the structure-optimized material to obtain an optimized sensor includes: After installing the structure-optimized material in the assembled sensor, judging whether there are electrode area, stress distribution, and electric field distribution in the cause analysis result; When there is an electrode area in the cause analysis result, increasing the current electrode area of the assembled sensor to obtain an increased electrode area; When there is a stress distribution in the cause analysis result, dispersing the stress receiving surface of the assembled sensor to obtain a dispersed receiving surface; When there is an electric field distribution in the cause analysis result, optimizing the electrode arrangement of the assembled sensor to obtain an optimized electrode arrangement; Determining the optimized sensor using the increased electrode area, the dispersed receiving surface, and the optimized electrode arrangement.

8. A structural design device applied to a brake pressure sensor, characterized in that, The device includes: A requirements analysis module, which is used to query the brake application scenarios, analyze the brake requirements of the brake application scenarios, collect the sensor materials of the brake application scenarios, analyze the material properties of the sensor materials, and analyze the material requirements of the brake requirements with respect to the sensor materials. Among them, the analysis of the material requirements of the brake requirements with respect to the sensor materials includes: Determine the numerical range of the preset material characteristics; Classify the same type of brake requirements in the brake requirements to obtain classified requirements; Based on the classified requirements, classify the numerical range to obtain a classified range; Take the intermediate value of the classified range as the material requirement of the classified requirement; A material determination module, which is used to calculate the material matching degree between the material properties and the material requirements, and based on the material matching degree, determine the structural material of the brake application scenario from the sensor materials; A sensor simulation module, which is used to assemble the structural materials to obtain an assembled sensor, query the geometric parameters of the assembled sensor, establish a piezoelectric constitutive model of the assembled sensor according to the geometric parameters, and perform force-electricity simulation on the assembled sensor through the piezoelectric constitutive model to obtain a force-electricity simulation result. Among them, the process of performing force-electricity simulation on the assembled sensor through the piezoelectric constitutive model to obtain a force-electricity simulation result includes: Input the elastic constant, piezoelectric constant and dielectric constant into the piezoelectric constitutive model to obtain a model to be solved; Discretize the geometric model corresponding to the piezoelectric constitutive model into finite element meshes; Define the mechanical boundary conditions and electrical boundary conditions of the finite element meshes; According to the mechanical boundary conditions and the electrical boundary conditions, solve the model to be solved in the finite element meshes to obtain a force-electricity simulation result; Among them, the force-electricity simulation result includes stress distribution and electric field distribution; A cause analysis module, which is used to calculate the brake sensitivity of the assembled sensor by using the force-electricity simulation result, calculate the brake failure rate of the assembled sensor by using the force-electricity simulation result, and perform defect cause analysis on the brake sensitivity and the brake failure rate to obtain a cause analysis result; A sensor design module, which is used to query the structural optimization materials of the assembled sensor based on the cause analysis result, optimize the structure of the assembled sensor by using the cause analysis result and the structural optimization materials to obtain an optimized sensor, and use the optimized sensor as the sensor design result of the brake application scenario.

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