Structural design method and device applied to brake pressure sensor

Abstract

The invention relates to the technical field of pressure sensors, and discloses a structural design method and device applied to a brake pressure sensor, and the method comprises the steps: analyzing the material performance of a sensor material, and analyzing the material demand of a brake demand related to the sensor material; the material matching degree between the material performance and the material requirement is calculated, and the structural material of the brake application scene is determined from the sensor materials; querying geometric parameters of the assembled sensor, and performing force-electricity simulation on the assembled sensor through the piezoelectric constitutive model; the brake sensitivity of the assembled sensor is calculated according to the force-electricity simulation result, the brake failure rate of the assembled sensor is calculated according to the force-electricity simulation result, and defect reason analysis is conducted on the brake sensitivity and the brake failure rate; and querying a structure optimization material of the assembled sensor, and performing structure optimization on the assembled sensor by utilizing the reason analysis result and the structure optimization material. According to the invention, the structural design and materials can be optimized, and the sensitivity and environmental adaptability of the sensor are improved.

Description

Technical Field

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

[0002] The existing piezoelectric sensor technology has significant defects in material properties, packaging design, manufacturing process and dynamic response, which seriously restricts its application in high-end brake systems. First, when designing brake pressure sensors, the existing technology only considers the performance of the brake pressure sensor itself in braking, and does not consider the matching of the brake pressure sensor with user needs. Secondly, the existing pressure sensors have uneven mechanical stress distribution, which is mainly manifested in the widespread stress concentration phenomenon in the sensor structure, resulting in premature fatigue damage in local areas, while affecting the uniformity of the electric field distribution, reducing signal accuracy, and local stress>50 MPa. Finally, the existing technology does not consider the mechanical-electrical coupling effect, and the simulation error is>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, the main purpose of which is to optimize the structural design and materials, thereby improving the sensitivity and environmental adaptability of the sensor.

[0005] To achieve the above object, the present invention provides a structural design method for a brake pressure sensor, comprising: Querying braking application scenarios, analyzing braking requirements of the braking application scenarios, collecting sensor materials for the braking application scenarios, analyzing material properties of the sensor materials, and analyzing the braking requirements for the sensor materials; calculating a material matching degree between the material performance and the material requirement, and determining a structural material for the brake application scenario from the sensor material based on the material matching degree; Assembling the structural material to obtain an assembled sensor, querying geometric parameters of the assembled sensor, establishing a piezoelectric constitutive model of the assembled sensor according to the geometric parameters, and performing mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model to obtain a mechanoelectric simulation result; The brake sensitivity of the assembled sensor is calculated using the mechanoelectrical simulation result, and the brake failure rate of the assembled sensor is calculated using the mechanoelectrical simulation result, and the cause of the defect of the brake sensitivity and the brake failure rate is analyzed to obtain a cause analysis result; Based on the cause analysis result, the structural optimization material of the assembled sensor is queried, and the structure of the assembled sensor is optimized using the cause analysis result and the structural optimization material to obtain an optimized sensor, and the optimized sensor is used as the sensor design result for the braking application scenario.

[0006] Optionally, the analyzing the material properties of the sensor material includes: calculating the mechanical-electrical conversion efficiency of the piezoelectric material in the sensor material; calculating a shear modulus of an elastomeric material in the sensor material; calculating the conductivity of the electrode material in the sensor material; calculating the dielectric strength of the insulating material in the sensor material; Calculating the thermal conductivity of the packaging material in the sensor material; Calculating carrier mobility of a signal processing circuit material in the sensor material; The electromechanical conversion efficiency, the shear modulus, the electrical conductivity, the dielectric strength, the thermal conductivity and the carrier mobility are used as material properties of the sensor material.

[0007] Optionally, the analyzing the braking requirement with respect to material requirements of the sensor material includes: Determining a numerical range of a preset material property; Classifying the same type of braking demands among the braking demands to obtain graded demands; Based on the classification requirement, the numerical interval is classified to obtain a classification interval; The middle value of the grading interval is used as the material requirement of the grading requirement.

[0008] Optionally, the calculating the material matching degree between the material performance and the material requirement includes: Check the numerical bottom line and numerical expectation in the material requirements; Based on the numerical bottom line and the numerical expectation, calculating the single material matching degree between the material performance and the material requirement; Obtaining a performance weight of the material performance; The single material matching degrees are weighted and summed using the performance weights to obtain the material matching degree.

[0009] Optionally, performing a mechanoelectric simulation on the assembled sensor by using the piezoelectric constitutive model to obtain a mechanoelectric simulation result includes: Inputting elastic constants, piezoelectric constants and dielectric constants into the piezoelectric constitutive model to obtain a model to be solved; Discretizing a geometric model corresponding to the piezoelectric constitutive model into a finite element mesh; Defining mechanical boundary conditions and electrical boundary conditions of the finite element mesh; According to the mechanical boundary conditions and the electrical boundary conditions, solving the model to be solved in the finite element grid to obtain a mechanoelectrical simulation result; The electromechanical simulation results include stress distribution and electric field distribution.

[0010] Optionally, calculating the braking sensitivity of the assembled sensor using the mechanoelectric simulation result includes: After installing the assembled sensor into a preset vehicle brake system, the instantaneous speed, rotation angle and equivalent resistance of the vehicle brake system are collected; The braking sensitivity of the assembled sensor is calculated according to the instantaneous speed, the rotation angle, the equivalent resistance and the electromechanical simulation result.

[0011] Optionally, the calculating the brake failure rate of the assembled sensor by using the mechanoelectric simulation result includes: After installing the assembled sensor into a preset vehicle brake system, the braking force of the vehicle brake system is collected; The braking failure rate of the assembled sensor is calculated according to the braking force and the mechanoelectrical simulation result.

[0012] Optionally, performing defect cause analysis on the brake sensitivity and the brake failure rate to obtain a cause analysis result includes: Determining whether the brake sensitivity is lower than a preset sensitivity threshold; When the braking sensitivity is lower than a 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; Determining whether the brake failure rate is higher than a preset failure rate threshold; When the brake failure rate is lower than a preset failure rate threshold; Obtaining 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; The first abnormal cause and the second abnormal cause are used as cause analysis results.

[0013] Optionally, the structural optimization of the assembled sensor using the cause analysis result and the structural optimization material to obtain an optimized sensor includes: After installing the structure optimization material in the assembled sensor, determining whether the electrode area, stress distribution, and electric field distribution exist in the cause analysis result; When the electrode area exists in the cause analysis result, increasing the current electrode area of ​​the assembled sensor to obtain an increased electrode area; When stress distribution exists in the cause analysis result, dispersing the stress receiving surface of the assembled sensor to obtain a dispersed receiving surface; When the electric field distribution exists in the cause analysis result, optimizing the electrode arrangement of the assembled sensor to obtain an optimized electrode arrangement; An optimized sensor is determined using the increased electrode area, the dispersed receiving surface, and the optimized electrode arrangement.

[0014] In order to solve the above problems, the present invention further provides a structural design device for a brake pressure sensor, the device comprising: A demand analysis module, used to query braking application scenarios, analyze braking requirements of the braking application scenarios, collect sensor materials for the braking application scenarios, analyze material properties of the sensor materials, and analyze the braking requirements with respect to material requirements of the sensor materials; A material determination module, used for calculating the material matching degree between the material performance and the material requirement, and determining the structural material of the brake application scenario from the sensor material based on the material matching degree; A sensor simulation module is used to assemble the structural material 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 a mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model to obtain a mechanoelectric simulation result; a cause analysis module, used to calculate the brake sensitivity of the assembled sensor using the mechanoelectrical simulation result, and calculate the brake failure rate of the assembled sensor using the mechanoelectrical simulation result, and perform defect cause analysis on the brake sensitivity and the brake failure rate to obtain a cause analysis result; The sensor design module is used to query the structural optimization materials of the assembled sensor based on the cause analysis results, optimize the structure of the assembled sensor using the cause analysis results and the structural optimization materials to obtain an optimized sensor, and use the optimized sensor as the sensor design result for the braking application scenario.

[0015] Compared with the problems described in the background technology, the embodiment of the present invention analyzes the material properties of the sensor material to analyze the characteristics of the material itself and the characteristics after being subjected to external stress. The embodiment of the present invention analyzes the material requirements of the sensor material in the braking requirements to analyze the requirements of the sensor material in the actual application scenario, thereby paving the way for the subsequent calculation of the matching degree between the sensor material and the actual requirements. The embodiment of the present invention calculates the material matching degree between the material properties and the material requirements to select materials based on the material matching degree, thereby improving the environmental adaptability of the sensor material. Furthermore, the embodiment of the present invention performs mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model to establish a sensor full-operating condition performance prediction model based on a multi-field coupling simulation platform. The actual test and simulation error is <3%, which significantly improves the design reliability. The stress distribution and electric field distribution are analyzed through finite element simulation. The embodiment of the present invention utilizes the mechanoelectric simulation structure The brake sensitivity of the assembled sensor is calculated by the result of the electromechanical simulation, and based on the relationship between the stress distribution, the electric field distribution and the sensitivity, it is judged whether the stress distribution and the electric field distribution need to be optimized by the performance of the sensitivity, so that the structure affecting the stress distribution and the electric field distribution is subsequently optimized, and the sensitivity of the sensor structure is improved. Further, the embodiment of the present invention calculates the brake failure rate of the assembled sensor by using the electromechanical simulation result, and based on the relationship between the stress distribution, the electric field distribution and the failure rate, it is judged whether the stress distribution and the electric field distribution need to be optimized by the performance of the failure rate, so that the structure affecting the stress distribution and the electric field distribution is subsequently optimized, and the failure rate of the sensor structure is reduced. Further, the embodiment of the present invention optimizes the structure of the assembled sensor by using the cause analysis result and the structure optimization material, so as to optimize the structural design and materials, and thus improve the sensitivity and environmental adaptability of the sensor. Therefore, the structural design method and device for the brake pressure sensor provided by the embodiment of the present invention can optimize the structural design and materials, and thus improve the sensitivity and environmental adaptability of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic flow chart of a structural design method for a brake pressure sensor provided in one embodiment of the present invention; Figure 2 A schematic diagram of a module for implementing the structural design device for a brake pressure sensor provided in one embodiment of the present invention.

[0017] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0018] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0019] The embodiment of the present application provides a structural design method for a brake pressure sensor. The execution subject of the structural design method for a brake pressure sensor includes but is not limited to at least one of the electronic devices such as a server and a terminal that can be configured to execute the method provided by the embodiment of the present application. In other words, the structural design method for a brake pressure sensor can be executed by software or hardware installed in 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.

[0020] Embodiment 1: Reference Figure 1 FIG. 1 is a flow chart of a structural design method for a brake pressure sensor provided in an embodiment of the present invention. In this embodiment, the structural design method for a brake pressure sensor includes:

[0021] S1. Query a braking application scenario, analyze the braking requirements of the braking application scenario, collect sensor materials for the braking application scenario, analyze the material properties of the sensor materials, and analyze the braking requirements with respect to the material requirements of the sensor materials.

[0022] In the embodiment of the present invention, the braking application scenario refers to the scenario in which the vehicle to which the brake pressure sensor is applied will brake, such as the braking scenario of a small car when driving at medium or low speeds in the city, and the braking scenario of a large truck when driving quickly on the highway. Furthermore, the braking demand refers to the demand for braking performance in the braking application scenario. For example, in the braking scenario of a small car when driving at medium or low speeds in the city, the braking demand is a medium braking ability, and in the braking scenario of a large truck when driving quickly on the highway, the braking demand is an extremely high braking ability. The braking ability refers to the ability to evaluate the quality of the brake pressure sensor, such as the accuracy of the brake pressure sensor in monitoring the pressure, the reaction speed in responding to the brake, and the durability. Wear and corrosion resistance, temperature stability, anti-electromagnetic interference, mechanical strength, waterproof and dust-proof, etc. The sensor material refers to the components required to build a complete piezoelectric sensor, such as piezoelectric materials, elastomeric materials, electrode materials, insulating materials, packaging materials, signal processing circuit materials, etc. The piezoelectric material is responsible for converting mechanical energy into electrical energy, the elastomeric material transmits pressure and protects the piezoelectric material, the electrode material collects the charge generated by the piezoelectric material (the piezoelectric material is a crystal structure, and the crystal structure changes under external pressure to generate positive and negative charges), the insulating material isolates the electrode to prevent short circuits, the packaging material protects the internal components, and prevents dust, moisture, and mechanical damage, and the signal processing circuit material amplifies and processes the piezoelectric signal.

[0023] Furthermore, the embodiment of the present invention analyzes the material properties of the sensor material to analyze the characteristics of the material itself and the characteristics after being subjected to external stress.

[0024] In one embodiment of the present invention, the analyzing the material properties of the sensor material includes: calculating the mechanical-electrical conversion efficiency of the piezoelectric material in the sensor material using the following formula: ; in, It represents the power-to-electricity conversion efficiency. represents the piezoelectric coefficient, represents the strain of the piezoelectric material, It represents the stress on the piezoelectric material. represents the dielectric constant, represents the transpose symbol; The shear modulus of the elastomeric material in the sensor material is calculated using the following formula: ; in, represents the shear modulus, represents the shear stress, represents the dimensionless shear strain; The conductivity of the electrode material in the sensor material is calculated using the following formula: ; in, represents the conductivity, represents the current density, Indicates the electric field strength; The dielectric strength of the insulating material in the sensor material is calculated using the following formula: ; in, represents the dielectric strength, represents the breakdown voltage, Indicates the thickness of the insulating material; The thermal conductivity of the packaging material in the sensor material is calculated using the following formula: ; in, represents thermal conductivity, represents the heat flow, Indicates the thickness of the packaging material, Indicates the heated area, Indicates the temperature difference on the surface of the packaging material; The carrier mobility of the signal processing circuit material in the sensor material is calculated using the following formula: ; in, represents the carrier mobility, represents the velocity of the charge carriers, Indicates the electric field strength on the signal processing circuit material; The electromechanical conversion efficiency, the shear modulus, the electrical conductivity, the dielectric strength, the thermal conductivity and the carrier mobility are used as material properties of the sensor material.

[0025] Furthermore, in an embodiment of the present invention, the material requirement refers to the requirement for each material under braking requirements. For example, when the braking requirement is for extremely high braking capability, the requirement for the mechanical-electrical conversion efficiency of the piezoelectric material is relatively high.

[0026] Furthermore, the embodiment of the present invention analyzes the demand for sensor materials in actual application scenarios by analyzing the material demand for the sensor material in relation to the braking demand, thereby laying the foundation for subsequent calculation of the matching degree between the sensor material and the actual demand.

[0027] In one embodiment of the present invention, the analysis of the braking demand regarding the material demand of the sensor material includes: determining a numerical range of a preset material property; classifying the same type of braking demand among the braking demand to obtain a graded demand; based on the graded demand, classifying the numerical range to obtain a graded interval; and using the middle value of the graded interval as the material requirement for the graded demand.

[0028] Among them, the material properties include electromechanical conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity and carrier mobility, and the numerical range refers to the numerical range between the lower limit and the upper limit of the material properties. Since the braking requirements are the requirements for electromechanical conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity and carrier mobility respectively, the graded requirements refer to the numerical level obtained by grading the numerical value of any material property among electromechanical conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity and carrier mobility. For example, if the material requirement has a higher requirement for the electromechanical conversion efficiency of the piezoelectric material, the graded requirement is a high-level requirement. If the material requirement has a lower requirement for the electromechanical conversion efficiency of the piezoelectric material, the graded requirement is a low-level requirement. When the total level types of the graded requirements are low, medium and equal, respectively, the total level types of the graded requirements are 3, then the numerical range is divided into 3 intervals from small to large, and these three intervals are the graded intervals.

[0029] S2. Calculate the material matching degree between the material performance and the material requirement, and determine the structural material of the braking application scenario from the sensor material based on the material matching degree.

[0030] The embodiment of the present invention calculates the material matching degree between the material performance and the material requirement, and selects the material based on the material matching degree, thereby improving the environmental adaptability of the sensor material.

[0031] In one embodiment of the present invention, the calculating of the material matching degree between the material performance and the material requirement includes: querying the numerical bottom line and the numerical expectation in the material requirement; and calculating the single material matching degree between the material performance and the material requirement based on the numerical bottom line and the numerical expectation using the following formula: ; in, Indicates the single material matching degree, Indicates The value of a material property, Indicates The numerical expectation of material demand, Indicates The numerical bottom line of material requirements; The performance weight of the material performance is obtained; and the single material matching degree is weightedly summed using the performance weight to obtain the material matching degree.

[0032] Among them, the numerical bottom line refers to the worst numerical value of each type of numerical value in the material requirement. For example, when the material requirement is the requirement for the electromechanical conversion efficiency of the piezoelectric material, the larger the electromechanical conversion efficiency value, the better the sensor material. The larger numerical value (upper limit) is used as the numerical expectation, and the smaller numerical value (lower limit) is used as the numerical bottom line. In addition, when selecting the numerical bottom line and the numerical expectation, it is necessary to determine the numerical requirements of the actual scenario. For example, in the scenario of a large truck, the numerical bottom line is set to a, and the numerical expectation is set to b. Furthermore, since the material properties include electromechanical conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity and carrier mobility, the weight of each type of performance in electromechanical conversion efficiency, shear modulus, electrical conductivity, dielectric strength, thermal conductivity and carrier mobility is different. The performance weight is generally determined based on past experience, such as a thermal conductivity weight of 0.4 and a shear modulus weight of 0.3.

[0033] Optionally, the process of determining the structural material of the braking application scenario from the sensor material based on the material matching degree refers to: 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, piezoelectric materials include quartz, piezoelectric ceramics (PZT), polyvinylidene fluoride (PVDF) and other candidate materials.

[0034] S3. Assembling 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, performing a mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model, and obtaining a mechanoelectric simulation result.

[0035] Optionally, the process of assembling the structural material to obtain the 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, and the sandwich structure mainly includes piezoelectric material, elastomeric material, electrode material, insulating material, and packaging material. 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.

[0036] In one embodiment of the present invention, establishing the piezoelectric constitutive model of the assembled sensor according to the geometric parameters includes: establishing the geometric model of the assembled sensor according to the geometric parameters; wherein the geometric model includes a piezoelectric material layer, an electrode and a supporting 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.

[0037] Among them, the supporting structure, such as a base, is used to support the assembled sensor so that the assembled sensor is placed in three dimensions. 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 constant, which are used to describe the characteristics of piezoelectric materials under the action of external forces and electric fields.

[0038] Furthermore, the embodiment of the present invention performs mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model, and establishes a sensor full-operating condition performance prediction model based on a multi-field coupling simulation platform. The actual test and simulation error is <3%, which significantly improves the design reliability, and analyzes the stress distribution and electric field distribution through finite element simulation.

[0039] In one embodiment of the present invention, the assembled sensor is subjected to a mechanoelectric simulation using the piezoelectric constitutive model to obtain a mechanoelectric simulation result, including: inputting elastic constants, piezoelectric constants and dielectric constants into the piezoelectric constitutive model to obtain a model to be solved; discretizing a geometric model corresponding to the piezoelectric constitutive model into a finite element mesh; defining mechanical boundary conditions and electrical boundary conditions of the finite element mesh; solving the model to be solved within the finite element mesh according to the mechanical boundary conditions and the electrical boundary conditions to obtain a mechanoelectric simulation result; wherein the mechanoelectric simulation result includes stress distribution and electric field distribution.

[0040] Among them, the elastic constant, piezoelectric constant and dielectric constant are specific values ​​corresponding to the parameters in the piezoelectric constitutive model. The model to be solved refers to the piezoelectric constitutive model whose stress distribution and electric field distribution are to be solved by finite element analysis software. The mechanical boundary conditions and electrical boundary conditions refer to the conditions on the boundaries of the defined geometric model in order to simulate the boundary behavior in the real system. These conditions can be displacement, force, pressure, temperature, etc., corresponding to the constraints or external loads in the real system.

[0041] Optionally, solving the model to be solved within the finite element mesh to obtain a mechanoelectric simulation result refers to a process of solving the stress distribution and electric field distribution in each finite element mesh by using finite element analysis software.

[0042] S4. Calculate the brake sensitivity of the assembled sensor using the mechanoelectrical simulation result, and calculate the brake failure rate of the assembled sensor using the mechanoelectrical simulation result, perform defect cause analysis on the brake sensitivity and the brake failure rate, and obtain a cause analysis result.

[0043] The embodiment of the present invention calculates the braking sensitivity of the assembled sensor by utilizing the results of the mechanoelectric simulation, and judges 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 sensitivity through the performance of the sensitivity, thereby subsequently optimizing the structure that affects the stress distribution and the electric field distribution, and improving the sensitivity of the sensor structure.

[0044] The brake sensitivity refers to the sensitivity of the electrical output of the piezoelectric sensor under the action of brake pressure in the performance of the dynamic characteristics of the brake system.

[0045] In one embodiment of the present invention, the use of the mechanoelectrical simulation result to calculate the braking sensitivity of the assembled sensor 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; according to the instantaneous speed, the rotation angle, the equivalent resistance and the mechanoelectrical simulation result, using the following formula to calculate the braking sensitivity of the assembled sensor: ; in, Indicates brake sensitivity. represents the piezoelectric coefficient, Indicates the coordinate position in the electromechanical simulation results The stress distribution of Indicates the coordinate position in the electromechanical simulation results The electric field distribution, represents the electrical quality factor of the piezoelectric material, represents the interval on the X-axis occupied by the electrodes in the assembled sensor, Indicates the electrode's share in the assembled sensor The interval on the axis, represents the instantaneous speed, represents the rotation angle, represents the equivalent resistance, Indicates the time interval during which the vehicle's braking system brakes. represents the time variable, represents a tensor subscript, represents the X-axis, Indicates the Y direction.

[0046] Among them, the automobile braking system refers to a series of special devices, such as brake discs, which apply a certain force to certain parts of the automobile (mainly wheels) to force braking to a certain extent. 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.

[0047] Furthermore, the embodiment of the present invention calculates the brake failure rate of the assembled sensor by utilizing the mechanoelectric simulation results, and judges 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 through the performance of the failure rate, thereby subsequently optimizing the structure affecting the stress distribution and the electric field distribution, and reducing the failure rate of the sensor structure.

[0048] The braking failure rate refers to the failure risk of the dynamic characteristics of the braking system caused by excessive stress and abnormal electric field of the piezoelectric sensor during braking.

[0049] In one embodiment of the present invention, the use of the mechanoelectrical simulation result to calculate the brake failure rate of the assembled sensor includes: after installing the assembled sensor into a preset vehicle brake system, collecting the brake force of the vehicle brake system; and calculating the brake failure rate of the assembled sensor according to the brake force and the mechanoelectrical simulation result using the following formula: ; in, Indicates the brake failure rate, In the electromechanical simulation results The stress distribution at time, represents the preset stress threshold, In the electromechanical simulation results The electric field distribution at time represents the preset electric field threshold, is the constant representing the electric field anomaly, express The electrical quality factor of the piezoelectric material at time represents the time variable, represents a tensor subscript, represents the X-axis, represents the Y direction, represents the equivalent resistance, express The braking force at the moment, express The mean of express The variance of represents the interval on the X-axis occupied by the electrodes in the assembled sensor, Indicates the electrode's share in the assembled sensor The interval on the axis.

[0050] The braking force refers to the maximum achievable rolling friction, also known as braking force.

[0051] 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 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 using the first abnormal cause and the second abnormal cause as the cause analysis result.

[0052] Among them, the preset sensitivity threshold and the preset failure rate threshold need to be set according to the actual scenario, which are mainly used to screen low sensitivity and high failure rate. The electrode area refers to the area between the X-axis and the , Y-axis range The area occupied by the calculated electrode, 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 whether the parameter affected by temperature is stable, for example, the electrical quality factor has temperature stability and will change due to temperature, the second abnormal cause has the same meaning as the first abnormal cause.

[0053] S5. Based on the cause analysis result, query the structural optimization material of the assembled sensor, use the cause analysis result and the structural optimization material to perform structural optimization on the assembled sensor to obtain an optimized sensor, and use the optimized sensor as the sensor design result for the braking application scenario.

[0054] Among them, the structural optimization materials include shielding layer materials, temperature compensation circuit materials, and filter circuit materials. The shielding layer materials are used to shield the interference of external electric fields and improve the uniformity of the electric field distribution of the sensor. The temperature compensation circuit materials are used to ensure the temperature stability of material performance. The filter circuit materials are used to improve the electric field strength of the electric field distribution, thereby enhancing the electrical signal output by the sensor.

[0055] Furthermore, the embodiment of the present invention optimizes the structure of the assembled sensor by utilizing the cause analysis results and the structural optimization material to optimize the structural design and materials, thereby improving the sensitivity and environmental adaptability of the sensor.

[0056] In one embodiment of the present invention, the use of the cause analysis result and the structure optimization material to perform structural optimization on the assembled sensor to obtain an optimized sensor includes: after installing the structure optimization material in the assembled sensor, determining whether the cause analysis result contains electrode area, stress distribution and electric field distribution; when the cause analysis result contains electrode area, increasing the current electrode area of ​​the assembled sensor to obtain an increased electrode area; when the cause analysis result contains stress distribution, dispersing the stress receiving surface of the assembled sensor to obtain a dispersed receiving surface; when the cause analysis result contains electric field distribution, optimizing the electrode arrangement of the assembled sensor to obtain an optimized electrode arrangement; and determining an optimized sensor using the increased electrode area, the dispersed receiving surface and the optimized electrode arrangement.

[0057] Optionally, the process of increasing the current electrode area of ​​the assembled sensor refers to a process of increasing in small amounts and multiple times. For example, if the total area is 10, the area size is increased by 0.5 each time, and the process of calculating the sensitivity and failure rate mentioned above is returned again to analyze whether the increased area can make the sensitivity and failure rate parameters normal. Furthermore, the process of dispersing the stress receiving surface of the assembled sensor refers to dispersing the materials that receive external pressure of the assembled sensor, for example, increasing an appropriate distance between each piece of material so that each piece of material is not too concentrated, and the dispersion distance is also a process of increasing in small amounts and multiple times. Furthermore, 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, adjusting the electrode to a branch electrode shape, a multi-layer / three-dimensional electrode shape, etc.

[0058] Compared with the problems described in the background technology, the embodiment of the present invention analyzes the material properties of the sensor material to analyze the characteristics of the material itself and the characteristics after being subjected to external stress. The embodiment of the present invention analyzes the material requirements of the sensor material in the braking requirements to analyze the requirements of the sensor material in the actual application scenario, thereby paving the way for the subsequent calculation of the matching degree between the sensor material and the actual requirements. The embodiment of the present invention calculates the material matching degree between the material properties and the material requirements to select materials based on the material matching degree, thereby improving the environmental adaptability of the sensor material. Furthermore, the embodiment of the present invention performs mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model to establish a sensor full-operating condition performance prediction model based on a multi-field coupling simulation platform. The actual test and simulation error is <3%, which significantly improves the design reliability. The stress distribution and electric field distribution are analyzed through finite element simulation. The embodiment of the present invention utilizes the mechanoelectric simulation structure The brake sensitivity of the assembled sensor is calculated by the result of the electromechanical simulation, and based on the relationship between the stress distribution, the electric field distribution and the sensitivity, it is judged whether the stress distribution and the electric field distribution need to be optimized by the performance of the sensitivity, so that the structure affecting the stress distribution and the electric field distribution is subsequently optimized, and the sensitivity of the sensor structure is improved. Further, the embodiment of the present invention calculates the brake failure rate of the assembled sensor by using the electromechanical simulation result, and based on the relationship between the stress distribution, the electric field distribution and the failure rate, it is judged whether the stress distribution and the electric field distribution need to be optimized by the performance of the failure rate, so that the structure affecting the stress distribution and the electric field distribution is subsequently optimized, and the failure rate of the sensor structure is reduced. Further, the embodiment of the present invention optimizes the structure of the assembled sensor by using the cause analysis result and the structure optimization material, so as to optimize the structural design and materials, and thus improve the sensitivity and environmental adaptability of the sensor. Therefore, the structural design method and device for the brake pressure sensor provided by the embodiment of the present invention can optimize the structural design and materials, and thus improve the sensitivity and environmental adaptability of the sensor.

[0059] Embodiment 2: like Figure 2 The figure shows a functional module diagram of a structural design device applied to a brake pressure sensor of the present invention.

[0060] The structural design device 200 for a brake pressure sensor of the present invention can be installed in an electronic device. According to the functions to be implemented, the structural design device for a brake pressure sensor can include a demand 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 module of the present invention can also be called a unit, which refers to a series of computer program segments that can be executed by a processor of an electronic device and can complete fixed functions, which are stored in the memory of the electronic device.

[0061] In the embodiment of the present invention, the functions of each module / unit are as follows: The demand analysis module 201 is used to query the braking application scenario, analyze the braking demand of the braking application scenario, collect sensor materials of the braking application scenario, analyze the material properties of the sensor materials, and analyze the material demand of the sensor materials related to the braking demand; The material determination module 202 is used to calculate the material matching degree between the material performance and the material requirement, and determine the structural material of the brake application scenario from the sensor material based on the material matching degree; The sensor simulation module 203 is used to assemble the structural material 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 mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model to obtain a mechanoelectric simulation result; The cause analysis module 204 is used to calculate the brake sensitivity of the assembled sensor using the mechanoelectrical simulation result, and calculate the brake failure rate of the assembled sensor using the mechanoelectrical simulation result, and perform defect cause analysis on the brake sensitivity and the brake failure rate to obtain a cause analysis result; The sensor design module 205 is used to query the structural optimization materials of the assembled sensor based on the cause analysis results, use the cause analysis results and the structural optimization materials to perform structural optimization on the assembled sensor to obtain an optimized sensor, and use the optimized sensor as the sensor design result for the braking application scenario.

[0062] In detail, each module in the structural design device 200 for a brake pressure sensor according to the embodiment of the present invention is used in the same manner as described above. Figure 1 The same technical means as the structural design method applied to the brake pressure sensor described in , and can produce the same technical effects, will not be repeated here.

[0063] It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A structural design method for a brake pressure sensor, characterized in that: The method comprises: Querying braking application scenarios, analyzing braking requirements of the braking application scenarios, collecting sensor materials for the braking application scenarios, analyzing material properties of the sensor materials, and analyzing the braking requirements for the sensor materials; calculating a material matching degree between the material performance and the material requirement, and determining a structural material for the brake application scenario from the sensor material based on the material matching degree; Assembling the structural material to obtain an assembled sensor, querying geometric parameters of the assembled sensor, establishing a piezoelectric constitutive model of the assembled sensor according to the geometric parameters, and performing mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model to obtain a mechanoelectric simulation result; The brake sensitivity of the assembled sensor is calculated using the mechanoelectrical simulation result, and the brake failure rate of the assembled sensor is calculated using the mechanoelectrical simulation result, and the cause of the defect of the brake sensitivity and the brake failure rate is analyzed to obtain a cause analysis result; Based on the cause analysis result, the structural optimization material of the assembled sensor is queried, and the structure of the assembled sensor is optimized using the cause analysis result and the structural optimization material to obtain an optimized sensor, and the optimized sensor is used as the sensor design result for the braking application scenario.

2. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The analyzing the material properties of the sensor material includes: calculating the mechanical-electrical conversion efficiency of the piezoelectric material in the sensor material; calculating a shear modulus of an elastomeric material in the sensor material; calculating the conductivity of the electrode material in the sensor material; calculating the dielectric strength of the insulating material in the sensor material; Calculating the thermal conductivity of the packaging material in the sensor material; Calculating carrier mobility of a signal processing circuit material in the sensor material; The electromechanical conversion efficiency, the shear modulus, the electrical conductivity, the dielectric strength, the thermal conductivity and the carrier mobility are used as material properties of the sensor material.

3. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The analyzing the braking requirement with respect to the material requirement of the sensor material includes: Determining a numerical range of a preset material property; Classifying the same type of braking demands among the braking demands to obtain graded demands; Based on the classification requirement, the numerical interval is classified to obtain a classification interval; The middle value of the grading interval is used as the material requirement of the grading requirement.

4. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The calculating the material matching degree between the material performance and the material requirement includes: Check the numerical bottom line and numerical expectation in the material requirements; Based on the numerical bottom line and the numerical expectation, calculating the single material matching degree between the material performance and the material requirement; Obtaining a performance weight of the material performance; The single material matching degrees are weighted and summed using the performance weights to obtain the material matching degree.

5. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The step of performing a mechanoelectric simulation on the assembled sensor by using the piezoelectric constitutive model to obtain a mechanoelectric simulation result includes: Inputting elastic constants, piezoelectric constants and dielectric constants into the piezoelectric constitutive model to obtain a model to be solved; Discretizing a geometric model corresponding to the piezoelectric constitutive model into a finite element mesh; Defining mechanical boundary conditions and electrical boundary conditions of the finite element mesh; According to the mechanical boundary conditions and the electrical boundary conditions, solving the model to be solved in the finite element grid to obtain a mechanoelectrical simulation result; The electromechanical simulation results include stress distribution and electric field distribution.

6. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The step of calculating the braking sensitivity of the assembled sensor using the electromechanical simulation result includes: After installing the assembled sensor into a preset vehicle brake system, the instantaneous speed, rotation angle and equivalent resistance of the vehicle brake system are collected; The braking sensitivity of the assembled sensor is calculated according to the instantaneous speed, the rotation angle, the equivalent resistance and the electromechanical simulation result.

7. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The calculating the brake failure rate of the assembled sensor by using the electromechanical simulation result includes: After installing the assembled sensor into a preset vehicle brake system, the braking force of the vehicle brake system is collected; The braking failure rate of the assembled sensor is calculated according to the braking force and the mechanoelectrical simulation result.

8. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The defect cause analysis of the brake sensitivity and the brake failure rate to obtain the cause analysis result includes: Determining whether the brake sensitivity is lower than a preset sensitivity threshold; When the braking sensitivity is lower than a 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; Determining whether the brake failure rate is higher than a preset failure rate threshold; When the brake failure rate is lower than a preset failure rate threshold; Obtaining 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; The first abnormal cause and the second abnormal cause are used as cause analysis results.

9. The structural design method for a brake pressure sensor according to claim 1, characterized in that: The step of optimizing the structure of the assembled sensor by using the cause analysis result and the structure optimization material to obtain an optimized sensor includes: After installing the structure optimization material in the assembled sensor, determining whether the electrode area, stress distribution, and electric field distribution exist in the cause analysis result; When the electrode area exists in the cause analysis result, increasing the current electrode area of ​​the assembled sensor to obtain an increased electrode area; When stress distribution exists in the cause analysis result, dispersing the stress receiving surface of the assembled sensor to obtain a dispersed receiving surface; When the electric field distribution exists in the cause analysis result, optimizing the electrode arrangement of the assembled sensor to obtain an optimized electrode arrangement; An optimized sensor is determined using the increased electrode area, the dispersed receiving surface, and the optimized electrode arrangement.

10. A structural design device for a brake pressure sensor, characterized in that: The device comprises: A demand analysis module, used to query braking application scenarios, analyze braking requirements of the braking application scenarios, collect sensor materials for the braking application scenarios, analyze material properties of the sensor materials, and analyze the braking requirements with respect to material requirements of the sensor materials; A material determination module, used for calculating the material matching degree between the material performance and the material requirement, and determining the structural material of the brake application scenario from the sensor material based on the material matching degree; A sensor simulation module is used to assemble the structural material 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 a mechanoelectric simulation on the assembled sensor through the piezoelectric constitutive model to obtain a mechanoelectric simulation result; a cause analysis module, used to calculate the brake sensitivity of the assembled sensor using the mechanoelectrical simulation result, and calculate the brake failure rate of the assembled sensor using the mechanoelectrical simulation result, and perform defect cause analysis on the brake sensitivity and the brake failure rate to obtain a cause analysis result; The sensor design module is used to query the structural optimization materials of the assembled sensor based on the cause analysis results, optimize the structure of the assembled sensor using the cause analysis results and the structural optimization materials to obtain an optimized sensor, and use the optimized sensor as the sensor design result for the braking application scenario.

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