Capacitive information sensing structure for industrial detection

Abstract

The invention relates to the technical field of industrial detection, and discloses an industrial detection-oriented capacitive information sensing structure, which comprises a motion transmission assembly, an external support protection assembly and a multi-dimensional sensing assembly, the motion transmission assembly comprises a telescopic shaft, a linear bearing and a sensing protective cover, the telescopic shaft is located on the central axis of the linear bearing and penetrates through the sensing protective cover, a left linear bearing shell and a right linear bearing shell are embedded into openings in the two ends of the sensing protective cover correspondingly, and a protective rear seat bin is arranged at the rear end of the sensing protective cover; a reset spring is arranged in the protection rear seat bin. The multi-dimensional sensing assembly is distributed in an inner cavity of the sensing protective cover in the axial direction and comprises a displacement sensing module, a temperature sensing module, a humidity sensing module, an air pressure sensing module and a natural vibration sensing module. According to the invention, through multi-dimensional data processing, vibration noise is reduced, and detection precision of roundness and coaxiality is improved; and through environment dielectric constant compensation, the accuracy of the detection result is further improved.

Description

Technical Field

[0001] This invention relates to the field of industrial inspection technology, and in particular to a capacitive information sensing structure for industrial inspection. Background Technology

[0002] In high-end equipment and semiconductor manufacturing, the roundness and coaxiality of components are core indicators that determine system performance. The industry widely employs capacitive sensing technology to reconstruct surface topology by capturing minute changes in the gap between the probe and the workpiece.

[0003] However, precision measurements are often subject to interference from multi-physics coupling. On the one hand, capacitance values ​​are highly dependent on dielectric properties; fluctuations in ambient humidity causing water molecule polarization, combined with changes in temperature and air pressure, can lead to nonlinear drift in the air dielectric constant. On the other hand, the relative displacement generated by the equipment's natural vibration often overlaps with the workpiece's waviness frequency; without independent monitoring data, this can easily lead to misjudgments of surface morphology. Furthermore, traditional external sensors suffer from spatial lag, failing to provide real-time feedback on the true local state of the probe.

[0004] Therefore, there is an urgent need to develop a composite sensing structure that deeply integrates micro-displacement detection with environmental parameters and self-vibration monitoring, and a capacitive information sensing structure for industrial detection that achieves real-time decoupling and compensation of multi-source errors through hardware integration, in order to solve the problems in the existing technology. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a capacitive information sensing structure for industrial inspection.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a capacitive information sensing structure for industrial inspection, comprising a motion transmission component, an external support and protection component, and a multi-dimensional sensing component;

[0007] The motion transmission assembly includes a telescopic shaft, a linear bearing, and a sensing protective cover. The telescopic shaft is located on the central axis of the linear bearing and passes through the sensing protective cover. Bearing seat holes are provided at both ends of the sensing protective cover. A left linear bearing housing and a right linear bearing housing are respectively embedded in the openings at both ends of the sensing protective cover. Left linear bearing balls and right linear bearing balls are respectively provided inside the left and right linear bearing housings. A protective rear chamber is provided at the rear end of the sensing protective cover. A return spring is provided inside the protective rear chamber and between the bottom of the inner wall of the protective rear chamber and the end face of the telescopic shaft. The top end of the telescopic shaft is spherical and slides in contact with the detected component.

[0008] The multi-dimensional sensing components are distributed axially in the internal cavity of the sensing protective cover, including a displacement sensing module, a temperature sensing module, a humidity sensing module, an air pressure sensing module, and a self-vibration sensing module;

[0009] The displacement sensing module is used to sense the axial absolute displacement of the telescopic shaft. The displacement sensing module is sleeved around the outer circumference of the telescopic shaft and includes a stator assembly and a mover assembly.

[0010] The stator assembly includes a metal ring, which is fixedly mounted on the stationary end of the equipment by an insulating support. The mover assembly includes a flexible metal sheet located on the outer surface of the telescopic shaft. The metal ring serves as a stationary electrode plate with a fixed axial length.

[0011] The temperature sensing module consists of a left temperature sensing support and a right temperature sensing support. A vertically extending temperature sensing support rail is provided between the left and right temperature sensing supports. A stationary temperature sensing insulating support is fixed on the upper part of the left and right temperature sensing supports. A stationary temperature sensing metal sheet is provided on the top surface of the stationary temperature sensing insulating support. Temperature sensing support rails are provided on the opposite sides of the left and right temperature sensing supports. A moving temperature sensing insulating support is provided on the temperature sensing support rails. A moving temperature sensing metal sheet is provided on the bottom surface of the moving temperature sensing insulating support. The stationary and moving temperature sensing insulating supports are connected by multiple symmetrically distributed memory springs. Temperature sensing support through holes are provided on both the left and right temperature sensing supports.

[0012] The humidity sensing module includes a moving humidity sensing metal plate and a stationary humidity sensing metal plate arranged parallel to each other. The stationary humidity sensing metal plate is fixed by a left humidity sensing support and a right humidity sensing support. A vertically extending humidity sensing support rail is provided between the left and right humidity sensing supports. The stationary humidity sensing metal plate is fixedly mounted on the bottom surface of the stationary humidity sensing insulating support. The humidity-sensitive sponge is mounted on the bottom surface of the moving humidity sensing insulating support. The stationary humidity sensing insulating support is fixedly mounted on the bottom surface of the humidity-sensitive sponge. The humidity-sensitive sponge elastically connects the moving humidity sensing insulating support and the stationary humidity sensing insulating support through deformation. The moving humidity sensing insulating support is fixedly mounted on the bottom surface of the moving humidity sensing metal plate. The moving humidity sensing insulating support slides on the humidity sensing support rail. The humidity sensing support rail provides a vertical movement track for the moving humidity sensing insulating support while restricting its radial and rotational degrees of freedom. Humidity sensing support through holes are provided on the left and right humidity sensing supports.

[0013] The air pressure sensing module includes a stationary air pressure sensing metal plate and a moving air pressure sensing metal plate arranged parallel to each other, a stationary air pressure sensing insulating support, a moving air pressure sensing insulating support, and an air chamber. The stationary air pressure sensing metal plate is fixedly installed on the bottom surface of the stationary air pressure sensing insulating support; the moving air pressure sensing metal plate is fixedly installed on the top surface of the moving air pressure sensing insulating support; the stationary air pressure sensing insulating support is fixedly supported by a left air pressure sensing support and a right air pressure sensing support; the moving air pressure sensing insulating support is connected to the left air pressure sensing support and the right air pressure sensing support via an air pressure sensing support guide rail; the air pressure sensing support guide rail is located between the moving air pressure sensing insulating support and the left and right air pressure sensing supports; the air chamber is located between the stationary air pressure sensing insulating support and the moving air pressure sensing insulating support.

[0014] The self-vibration sensing module includes a self-vibration sensing left support and a self-vibration sensing right support. Vertically extending self-vibration sensing support rails are provided on the inner walls of the left and right self-vibration sensing support rails. A self-vibration sensing static insulating support is fixedly installed on the upper part of the self-vibration sensing support rails. A self-vibration sensing static metal plate is provided on the top surface of the self-vibration sensing static insulating support. A self-vibration sensing moving insulating support is slidably arranged within the self-vibration sensing support rails. A self-vibration sensing moving metal plate is provided on the bottom surface of the self-vibration sensing moving insulating support. The self-vibration sensing static insulating support and the self-vibration sensing moving insulating support are elastically connected by multiple symmetrically arranged self-vibration sensing springs. The self-vibration sensing support rails provide a vertical moving track for the self-vibration sensing moving insulating support while restricting its horizontal degree of freedom.

[0015] As a further description of the above technical solution:

[0016] The left and right linear bearing balls form a clearance fit with the outer surface of the telescopic shaft, which restricts the telescopic shaft to only perform linear reciprocating motion along the axial direction, while also limiting its radial runout.

[0017] As a further description of the above technical solution:

[0018] The protective rear seat and the sensing shield are fixed together by either a threaded connection or a snap-fit ​​connection, forming a closed internal cavity.

[0019] As a further description of the above technical solution:

[0020] The metal ring and the flexible metal sheet maintain a preset radial gap, and the two are insulated from each other to form a variable area capacitor.

[0021] As a further description of the above technical solution:

[0022] The flexible metal sheet has a gradually changing width on the axial unfolding surface of the telescopic shaft, and the width of the flexible metal sheet gradually changes along the extension direction of the telescopic shaft.

[0023] As a further description of the above technical solution:

[0024] The air chamber is a sealed cavity made of elastic material, which is filled with normal pressure gas. Both the stationary and moving metal pressure sensing plates are located outside the air chamber.

[0025] As a further description of the above technical solution:

[0026] It also includes a data correction and calculation algorithm running in the processing unit to eliminate the interference of environmental medium changes and mechanical vibration on capacitive displacement measurement. The algorithm steps are as follows:

[0027] Step 1: Perform dynamic error correction based on the self-vibration sensing module. The system synchronously acquires the main measurement capacitance signal of the displacement sensing module and the vibration capacitance signal of the self-vibration sensing module. Due to the possibility of external vibration or inertial impact during the measurement process of the capacitive information sensing structure, a small vibration that is not for the measurement purpose may occur between the telescopic shaft and the metal ring. The processing unit monitors the frequency and amplitude of the capacitance fluctuation fed back by the self-vibration sensing module in real time, and uses Kalman filtering to remove noise components with the same frequency as the vibration from the original data of the displacement sensing module. At the same time, the original displacement value is reverse-compensated according to the vibration quantization data to obtain a pure displacement signal after removing mechanical vibration interference.

[0028] Step 2: Perform relative permittivity correction based on temperature sensing module, humidity sensing module and air pressure sensing module. The system synchronously collects the main measurement capacitance signal of displacement sensing module and the capacitance signals of temperature sensing module, humidity sensing module and air pressure sensing module, and calculates the relative permittivity of air in the current environment using the corrected Ciddor formula.

[0029] Step 3: Perform comprehensive calculation of geometric tolerances. The processing unit uses the high-precision absolute displacement data after noise reduction and environmental compensation as the basic data, and combines it with the continuous displacement data obtained during multi-point scanning. Through least squares fitting or spatial geometric algorithms, it calculates the geometric tolerances such as coaxiality and roundness of the measured hole or shaft, and finally outputs the corrected measurement report.

[0030] The present invention has the following beneficial effects:

[0031] 1. In this invention, multi-dimensional data processing is used to reduce vibration noise and improve the detection accuracy of coaxiality and roundness.

[0032] 2. In this invention, displacement, temperature, humidity and air pressure parameters are simultaneously sensed through a capacitive information sensing structure, and the accuracy of the detection results is further improved through environmental dielectric constant compensation.

[0033] 3. In this invention, the compact integrated design overcomes the spatial lag and complex wiring problems of traditional external sensors, which is of great engineering significance for supporting the manufacturing of high-end equipment and semiconductor components. Attached Figure Description

[0034] Figure 1 This is an overall structural diagram of a capacitive information sensing structure for industrial detection proposed in this invention.

[0035] Figure 2 This is an enlarged view of the temperature sensing module and humidity sensing module of the capacitive information sensing structure for industrial testing proposed in this invention.

[0036] Figure 3 This is an enlarged view of the air pressure sensing module and the self-vibration sensing module of the capacitive information sensing structure for industrial testing proposed in this invention.

[0037] Figure 4 This is a cross-sectional view at point AA of a capacitive information sensing structure for industrial testing proposed in this invention.

[0038] Figure 5 This is a cross-sectional view at point BB of a capacitive information sensing structure for industrial testing proposed in this invention.

[0039] Figure 6 This is a schematic diagram of a capacitive information sensing structure for industrial detection proposed in this invention, showing displacement sensing modules in different states.

[0040] Figure 7 This is a schematic diagram showing the state of the temperature sensing module under different ambient temperatures of a capacitive information sensing structure for industrial testing proposed in this invention.

[0041] Figure 8 This is a schematic diagram of the humidity sensing module under different environmental humidity conditions, representing a capacitive information sensing structure for industrial testing proposed in this invention.

[0042] Figure 9 This is a schematic diagram of the pressure sensing module under different environmental pressures, representing a capacitive information sensing structure for industrial testing proposed in this invention.

[0043] Figure 10 This is a schematic diagram of the self-vibration sensing module state under different scenarios of a capacitive information sensing structure for industrial testing proposed in this invention.

[0044] Figure 11 This is a schematic diagram of the displacement sensing module structure of a capacitive information sensing structure for industrial detection proposed in this invention.

[0045] Figure 12 This is a schematic diagram of a temperature sensing module structure of a capacitive information sensing structure for industrial detection proposed in this invention.

[0046] Figure 13 This is a schematic diagram of a humidity sensing module structure of a capacitive information sensing structure for industrial testing proposed in this invention.

[0047] Figure 14 This is a schematic diagram of a possible implementation of a capacitive information sensing structure for industrial inspection proposed in this invention (measuring concentricity).

[0048] Figure 15 This is a schematic diagram of a possible implementation of a capacitive information sensing structure for industrial inspection proposed in this invention (circularity measurement).

[0049] Legend: 1. Telescopic shaft; 2. Linear bearing; 2a. Left linear bearing housing; 2c. Left linear bearing ball; 2b. Right linear bearing housing; 2d. Right linear bearing ball; 3. Sensing protective cover; 4. Displacement sensing module; 4a. Insulating support; 4b. Metal ring; 4c. Flexible metal sheet; 5. Temperature sensing module; 5a. Temperature sensing stationary metal sheet; 5b. Temperature sensing stationary insulating support; 5c. Temperature sensing left support; 5d. Temperature sensing right support; 5e. Temperature sensing moving insulating support; 5f. Temperature sensing moving metal sheet; 5g. Memory spring; 5h. Temperature sensing support guide rail; 5k. Temperature sensing support through hole; 6. Humidity sensing module; 6a. Humidity sensing stationary metal sheet; 6b. Humidity sensing stationary insulating support; 6c. Humidity sensing left support; 6d. Humidity sensing right support; 6e. Humidity sensing moving... 6. Insulating support; 6f. Moisture-sensing metal sheet; 6g. Humidity-sensitive sponge; 6h. Humidity-sensing support rail; 6k. Humidity-sensing support through hole; 7. Air pressure sensing module; 7a. Stationary metal sheet; 7b. Stationary insulating support; 7c. Left support; 7d. Right support; 7e. Moist insulating support; 7f. Moist metal sheet; 7g. Air chamber; 7h. Air pressure sensing support rail; 8. Self-vibration sensing module; 8a. Stationary metal sheet; 8b. Stationary insulating support; 8c. Left support; 8d. Right support; 8e. Moist insulating support; 8f. Moist metal sheet; 8g. Self-vibration sensing spring; 8h. Self-vibration sensing support rail; 9. Protective rear seat compartment; 10. Reset spring; 11. Component under test. Detailed Implementation

[0050] The present disclosure will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present disclosure and should not be used to limit the scope of protection of the present disclosure.

[0051] Figure 1-15 This disclosure provides an overall structural diagram of a capacitive information sensing structure for industrial testing, enlarged views of the temperature sensing module and humidity sensing module, enlarged views of the air pressure sensing module and self-vibration sensing module, a cross-sectional view at point AA, a cross-sectional view at point BB, schematic diagrams of the displacement sensing module in different states, schematic diagrams of the temperature sensing module in different ambient temperatures, schematic diagrams of the humidity sensing module in different ambient humidity levels, schematic diagrams of the air pressure sensing module in different ambient air pressure levels, schematic diagrams of the self-vibration sensing module in different scenarios, a structural schematic diagram of the displacement sensing module, a structural schematic diagram of the temperature sensing module, a structural schematic diagram of the humidity sensing module, a schematic diagram of one possible implementation (measuring concentricity), and a schematic diagram of one possible implementation (measuring roundness). See also... Figure 1-15 In this embodiment, each module (device, component, etc.) will be discussed in detail.

[0052] Combined with appendix Figure 1-11 A capacitive information sensing structure for industrial inspection is composed of motion transmission components, external support and protection components, and multi-dimensional sensing components.

[0053] The motion transmission assembly includes a telescopic shaft 1, a linear bearing 2, and a sensing protective cover 3. The telescopic shaft 1 is positioned along the central axis of the linear bearing 2 and passes through the sensing protective cover 3. Bearing seat holes are provided at both ends of the sensing protective cover 3, with the left and right linear bearing housings embedded in their openings. The left and right linear bearing balls are respectively housed within the housings. The left and right linear bearing balls form a clearance fit with the outer surface of the telescopic shaft 1. This design allows the telescopic shaft 1 to perform linear reciprocating motion only along the axial direction, effectively limiting its radial runout. A protective rear chamber 9 is connected to the rear end of the sensing protective cover 3. The protective rear chamber 9 and the sensing protective cover 3 can be fixed together by either threads or snap-fit ​​connections, forming a closed internal cavity. A return spring 10 is installed inside the protective rear chamber 9, between its inner wall bottom and the tail end face of the telescopic shaft 1. The top end of the telescopic shaft 1 has a spherical structure for maintaining sliding contact with the component being detected 11.

[0054] A multi-dimensional sensing component is arranged axially within the internal cavity of the sensing protective cover 3, including a displacement sensing module 4, a temperature sensing module 5, a humidity sensing module 6, an air pressure sensing module 7, and a self-vibration sensing module 8. The displacement sensing module 4 senses the absolute axial displacement of the telescopic shaft 1. This module is ringed around the outer circumference of the telescopic shaft 1 and includes a stator assembly and a mover assembly. The stator assembly has a metal ring 4b, which is fixedly mounted on the stationary end of the equipment via an insulating support 4a. The mover assembly includes a flexible metal sheet 4c attached to the outer surface of the telescopic shaft 1. The metal ring 4b acts as a stationary plate, with a fixed axial length, and maintains a preset radial gap with the flexible metal sheet 4c. The two are insulated from each other and form a variable-area capacitor. The flexible metal sheet 4c has a gradually changing width geometry on the axial unfolding surface of the telescopic shaft 1, with its width gradually varying along the extension direction of the telescopic shaft 1.

[0055] The temperature sensing module 5 consists of a left temperature sensing support 5c and a right temperature sensing support 5d, connected by a vertically extending temperature sensing support rail 5h. A stationary temperature sensing insulating support 5b is mounted on the upper frame of both the left and right temperature sensing supports 5c and 5d, with a stationary temperature sensing metal plate 5a mounted on its top surface. The vertically extending temperature sensing support rail 5h connects the left and right temperature sensing supports 5c and 5d, with a moving temperature sensing metal plate 5f on its bottom surface. The stationary temperature sensing insulating support 5b and the moving temperature sensing insulating support 5e are connected by multiple symmetrically distributed memory springs 5g. Both the left and right temperature sensing supports 5c and 5d have through-holes 5k for temperature sensing.

[0056] The humidity sensing module 6 includes a humidity-sensing moving metal plate 6f and a humidity-sensing stationary metal plate 6a arranged parallel to each other. The humidity-sensing stationary metal plate 6a is fixed by a humidity-sensing left support 6c and a humidity-sensing right support 6d, with a vertically extending humidity-sensing support rail 6h between the two supports. The humidity-sensing stationary metal plate 6a is fixed to the bottom surface of the humidity-sensing stationary insulating support 6b, and the humidity-sensitive sponge 6g is set on the bottom surface of the humidity-sensing moving insulating support 6e. The humidity-sensing stationary insulating support 6b is fixed to the bottom surface of the humidity-sensitive sponge 6g, so that the humidity-sensitive sponge 6g elastically connects the humidity-sensing moving insulating support 6e and the humidity-sensing stationary insulating support 6b through its own deformation. The humidity-sensing moving insulating support 6e is also fixed to the bottom surface of the humidity-sensing moving metal plate 6f and slides on the humidity-sensing support rail 6h. This rail provides a vertical movement track for the humidity-sensing moving insulating support 6e, while restricting its radial and rotational degrees of freedom. Humidity-sensing support through holes 6k are also provided on the humidity-sensing left support 6c and the humidity-sensing right support 6d.

[0057] The air pressure sensing module 7 includes a stationary air pressure sensing metal plate 7a and a moving air pressure sensing metal plate 7f arranged parallel to each other, as well as a stationary air pressure sensing insulating support 7b, a moving air pressure sensing insulating support 7e, and an air chamber 7g. The stationary air pressure sensing metal plate 7a is fixed to the bottom surface of the stationary air pressure sensing insulating support 7b; the moving air pressure sensing metal plate 7f is fixed to the top surface of the moving air pressure sensing insulating support 7e. The stationary air pressure sensing insulating support 7b is fixedly supported by a left air pressure sensing support 7c and a right air pressure sensing support 7d; a vertically extending air pressure sensing support guide rail 7h is provided between the left air pressure sensing support 7c and the right air pressure sensing support 7d; the moving air pressure sensing insulating support 7e is connected to the left air pressure sensing support 7c and the right air pressure sensing support 7d through the air pressure sensing support guide rail 7h. The air chamber 7g is formed by sealing with an elastic material, and is filled with atmospheric pressure gas. It is located between the air pressure sensing static insulating support 7b and the air pressure sensing moving insulating support 7e. The air pressure sensing static metal plate 7a and the air pressure sensing moving metal plate 7f are both arranged outside the air chamber 7g.

[0058] The self-vibration sensing module 8 includes a self-vibration sensing left support 8c and a self-vibration sensing right support 8d, with a vertically extending self-vibration sensing support guide rail 8h on its inner wall. A self-vibration sensing static insulating support 8b is fixedly installed on the upper part of the guide rail, with a self-vibration sensing static metal plate 8a on its top surface; a self-vibration sensing moving insulating support 8e is slidably arranged inside the guide rail, with a self-vibration sensing moving metal plate 8f on its bottom surface. The self-vibration sensing static insulating support 8b and the self-vibration sensing moving insulating support 8e are elastically connected by multiple symmetrically arranged self-vibration sensing springs 8g. The self-vibration sensing support guide rail 8h provides a vertical moving track for the self-vibration sensing moving insulating support 8e, while restricting its horizontal degree of freedom.

[0059] It should be noted that the flexible metal sheet 4c, metal ring 4b, temperature-sensing stationary metal sheet 5a, temperature-sensing moving metal sheet 5f, humidity-sensing moving metal sheet 6a, humidity-sensing stationary metal sheet 6f, air pressure-sensing moving metal sheet 7a, air pressure-sensing stationary metal sheet 7f, self-vibration-sensing stationary metal sheet 8a, and self-vibration-sensing moving metal sheet 8f are all made of conductive materials, preferably but not limited to copper foil or aluminum foil, or flexible copper-clad laminate (FPC), or graphite coating. Any metal conductor that can be used as the two plates of a capacitor can be used.

[0060] The insulating support 4a, the temperature-sensing static insulating support 5b, the temperature-sensing moving insulating support 5e, the humidity-sensing static insulating support 6b, the humidity-sensing moving insulating support 6e, the air pressure-sensing static insulating support 7b, the air pressure-sensing moving insulating support 7e, the self-vibration-sensing static insulating support 8b, and the self-vibration-sensing moving insulating support 8e are made of insulating materials, preferably PVC plastic or alumina ceramic or zirconium oxide ceramic.

[0061] The temperature sensing left support 5c, temperature sensing right support 5d, humidity sensing left support 6c, humidity sensing right support 6d, air pressure sensing left support 7c, air pressure sensing right support 7d, self-vibration sensing left support 8c, and self-vibration sensing right support 8d are preferably made of insulating materials, preferably PVC plastic or alumina ceramic or zirconium oxide ceramic.

[0062] The memory spring 5g is preferably a memory alloy, including but not limited to nickel-titanium alloys, titanium-nickel-copper alloys, titanium-nickel-iron alloys, titanium-nickel-chromium alloys, copper-nickel alloys, copper-aluminum alloys, copper-zinc alloys, iron alloys, or thermotropic shape memory polymer materials, or shape memory fibers.

[0063] The humidity-sensitive sponge 6g is preferably polyvinyl alcohol, polyurethane foam, or barium zirconate.

[0064] The reference gas encapsulated in the gas chamber 7g is preferably, but not limited to, dry nitrogen or dry argon; a gas membrane is provided on the outside of the gas chamber 7g, preferably, but not limited to, a polyimide film or a liquid crystal polymer film.

[0065] The temperature sensing support rail 5h, humidity sensing support rail 6h, air pressure sensing support rail 7h, and self-vibration sensing support rail 8h are preferably made of wear-resistant materials, but are not limited to stainless steel, copper alloy, or engineering plastics.

[0066] The self-vibration sensing spring 8g is preferably, but not limited to, 3J53 alloy.

[0067] The telescopic shaft 1 is not limited to metal or insulating materials, but has a certain supporting strength. When the telescopic shaft 1 is made of metal, an insulating layer is provided on the surface of the telescopic shaft 1.

[0068] The linear bearing 2 is a commonly used linear bearing in industry.

[0069] The sensing protective shield 3 is not limited to metal or insulating materials, but possesses a certain supporting strength. In actual use, the sensing protective shield 3 is rigidly fixed to the stationary ground component and remains stationary relative to the ground.

[0070] like Figure 12 As shown, this is a schematic diagram of the temperature sensing module structure. In actual use, the structure of the self-vibration sensing module is connected in the same way as that of the temperature sensing module, except that the sensitive element of the temperature sensing module is a memory spring, while the sensitive element of the self-vibration sensing module is a self-vibration sensing spring. In order to reduce the influence of temperature, the self-vibration sensing module does not have through holes in the left and right supports of the self-vibration sensing module.

[0071] like Figure 13The diagram shows the structure of the humidity sensing module. In actual use, the structure of the air pressure sensing module is the same as that of the humidity sensing module, except that the sensitive element of the humidity sensing module is a humidity-sensitive sponge, while the sensitive element of the air pressure sensing module is an air chamber. There are no through holes on the left and right supports of the air pressure sensing module.

[0072] A data correction and resolution algorithm that runs in a processing unit.

[0073] The algorithm aims to reduce the interference of environmental medium changes and mechanical vibrations on capacitive displacement measurement. The steps are as follows:

[0074] Step 1: Perform dynamic error correction based on the self-vibration sensing module 8. The system synchronously acquires the main measurement capacitance signal of the displacement sensing module 4 and the vibration capacitance signal of the self-vibration sensing module 8. Due to the potential for external vibrations or inertial impacts during the measurement process of the capacitive information sensing structure, minor non-measuring vibrations may occur between the telescopic shaft 1 and the metal ring 4b. The processing unit monitors the frequency and amplitude of the capacitance fluctuations fed back by the self-vibration sensing module 8 in real time, and uses Kalman filtering to remove noise components with the same frequency as the vibration from the raw data of the displacement sensing module 4; simultaneously, it performs reverse compensation on the original displacement value based on the vibration quantization data, thereby obtaining a pure displacement signal after removing mechanical vibration interference.

[0075] Step 2: Perform relative permittivity correction based on temperature sensing module 5, humidity sensing module 6 and air pressure sensing module 7. The system synchronously collects the main measurement capacitance signal of displacement sensing module 4 and the capacitance signals of temperature sensing module 5, humidity sensing module 6 and air pressure sensing module 7, and calculates the relative permittivity of air under the current environment using the corrected Ciddor formula.

[0076] Step 3: Perform comprehensive calculation of geometric tolerances. The processing unit uses the high-precision absolute displacement data after noise reduction and environmental compensation as the base data. Combined with the continuous displacement data acquired during multi-point scanning, it calculates the coaxiality, roundness, and other geometric tolerances of the measured hole or shaft through least squares fitting or spatial geometric algorithms, and finally outputs the corrected measurement report.

[0077] To further illustrate the execution process of the above data correction and calculation algorithm, this embodiment uses the following mathematical model for calculation:

[0078] 1. Dynamic error correction of the self-vibration sensing module

[0079] Let the original capacitance value collected by displacement sensing module 4 be... The vibration capacitance value collected by the self-vibration sensing module 8 is .

[0080] First, calculate the instantaneous displacement caused by mechanical vibration. The system is based on Hooke's Law and the parallel-plate capacitor model, and the following reverse compensation formula is established:

[0081]

[0082] In the formula: This represents the initial capacitance value of the self-vibration sensing module in a static state. The pre-calibrated vibration-displacement coupling coefficient (unit: mm) is used to characterize the influence of the vibration measured by the self-vibration sensing module on the extension and retraction displacement of the main measuring shaft.

[0083] Next, Kalman filtering is introduced for noise reduction. The state equation and observation equation are established:

[0084]

[0085] Where: state variables For a moment The true displacement estimate; the observed value The displacement is taken from the coarse displacement after vibration compensation, i.e. ; and These are process noise and observation noise, respectively.

[0086] Through iterative updates, a clean displacement signal after removing mechanical vibration interference is output. .

[0087] 2. Environmental dielectric constant compensation correction

[0088] Based on data from temperature sensing module 5, humidity sensing module 6, and air pressure sensing module 7, the relative permittivity of air under the current environment is calculated using the modified Ciddor formula. :

[0089]

[0090] In the formula: The current air pressure (Pa) The current temperature (K). The current relative humidity (%) The gas constant is For the molar mass of air, As the compression factor, , This is the dielectric constant correction factor.

[0091] Based on the principle of capacitive displacement sensors, calculate the environmental correction coefficient. And obtain the true value of absolute displacement. :

[0092]

[0093]

[0094] In the formula: is the standard environmental dielectric constant during calibration.

[0095] 3. Comprehensive calculation of geometric tolerances

[0096] In industrial inspection, center positioning, eccentricity estimation, and roundness error evaluation are obtained. The set of true absolute displacement data points at each location. Convert to rectangular coordinates The objective function is constructed using the least squares method. :

[0097]

[0098] By solving Solve for the coordinates of the fitted circle center. and the fitted radius .

[0099] Finally, the roundness error of the measured cross-section is calculated. :

[0100]

[0101] In practical application, the parameters to be calculated vary depending on the selected value of N. When N is 3, the concentricity of the shaft can be calculated using the algorithm, as illustrated in the diagram below. Figure 14 As shown. When N is greater than or equal to 8, the roundness of the shaft can be calculated using the algorithm. A schematic diagram is shown below. Figure 15 As shown.

[0102] When this invention is in operation, when the telescopic shaft 1 is along the axial direction (e.g.) Figure 6 When the flexible metal sheet 4c (as indicated by the middle arrow) moves, the area of ​​the flexible metal sheet 4c relative to the stationary metal ring 4b changes. Because the flexible metal sheet 4c has a gradually changing width, when it passes through the metal ring 4b, the effective surface area of ​​the flexible metal sheet 4c covered (directly facing) by the metal ring 4b changes continuously with the change in axial position. According to the parallel plate capacitance formula, the capacitance value between the two plates corresponds to the area of ​​the opposing plates. By measuring the capacitance value between the metal ring 4b and the flexible metal sheet 4c, the current absolute displacement of the telescopic shaft 1 can be accurately calculated.

[0103] A stationary temperature-sensing metal plate 5a and a moving temperature-sensing metal plate 5f are arranged parallel to each other vertically, forming a variable capacitor. When the ambient temperature changes, the memory spring 5g deforms axially based on the shape memory effect of the memory alloy, pushing the moving insulating support 5e to move along the axis of the temperature-sensing support rail 5h under the guidance and constraint of the rail. This causes a change in the distance between the stationary and moving metal plates 5a and 5f, resulting in a change in the capacitance value. By collecting the change in capacitance value through the circuit system, accurate quantitative measurement of the ambient temperature can be achieved.

[0104] A moving humidity-sensing metal plate 6f and a stationary humidity-sensing metal plate 6a are positioned opposite each other to form a variable capacitor. When the air humidity changes, the humidity-sensitive sponge 6g compresses or expands to different degrees depending on the humidity level, causing the moving humidity-sensing insulating support 6e to move along the axis of the humidity-sensing support rail 6h under its guidance. This changes the distance between the plates of the moving and stationary humidity-sensing metal plates 6f and 6a, thus altering the capacitance between them. The change in capacitance is collected by a circuit system to achieve quantitative measurement of the humidity parameter.

[0105] A stationary pressure-sensing metal plate 7a and a moving pressure-sensing metal plate 7f are arranged opposite each other to form a variable capacitor. When the ambient air pressure changes, a pressure difference is formed between the ambient air pressure and the reference pressure inside the air chamber 7g, which is a completely sealed cavity. Under the action of this pressure difference, the moving pressure-sensing metal plate 7f moves along the guide direction of the pressure-sensing support rail 7h along the moving pressure-sensing insulating support 7e. This causes a change in the distance between the plates of the stationary and moving pressure-sensing metal plates 7a and 7f, which in turn causes a change in the capacitance value between them. The change in capacitance value is collected by a circuit system to achieve quantitative measurement of the air pressure parameter.

[0106] The self-vibration sensing stationary metal sheet 8a and the self-vibration sensing moving metal sheet 8f are arranged opposite each other to form a variable capacitor. When the capacitive information sensing structure experiences vibration disturbance, the self-vibration sensing moving metal sheet 8f moves along the axial direction with the self-vibration sensing moving insulating support 8e under the guidance and constraint of the self-vibration sensing support guide rail 8h, causing a change in the distance between the self-vibration sensing stationary metal sheet 8a and the self-vibration sensing moving metal sheet 8f, which in turn causes a change in the capacitance value. By acquiring the change in capacitance value through the circuit system, accurate quantitative measurement of vibration parameters can be achieved.

[0107] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents. In conclusion, if those skilled in the art, inspired by this description, design similar structural methods and embodiments without departing from the inventive spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A capacitive information sensing structure for industrial inspection, characterized in that, This includes motion transmission components, external support and protection components, and multi-dimensional sensing components; The motion transmission assembly includes a telescopic shaft (1), a linear bearing (2), and a sensing protective cover (3). The telescopic shaft (1) is located on the central axis of the linear bearing (2) and passes through the sensing protective cover (3). The two ends of the sensing protective cover (3) are respectively provided with bearing seat holes. The two ends of the sensing protective cover (3) are respectively embedded with the outer shell of the left linear bearing (2) and the outer shell of the right linear bearing (2). The outer shell of the left linear bearing (2) and the outer shell of the right linear bearing (2) are respectively provided with the ball bearing of the left linear bearing (2) and the ball bearing of the right linear bearing (2). The rear end of the sensing protective cover (3) is provided with a protective rear seat chamber (9). The protective rear seat chamber (9) is located between the bottom of the inner wall of the protective rear seat chamber (9) and the end face of the telescopic shaft (1). The top end of the telescopic shaft (1) is spherical and slides in contact with the detected component (11). The multidimensional sensing components are distributed along the axial direction in the internal cavity of the sensing protective cover (3), including a displacement sensing module (4), a temperature sensing module (5), a humidity sensing module (6), an air pressure sensing module (7), and a self-vibration sensing module (8); The displacement sensing module (4) is used to sense the axial absolute displacement of the telescopic shaft (1). The displacement sensing module (4) is sleeved around the outer circumference of the telescopic shaft (1). The displacement sensing module (4) includes a stator assembly and a mover assembly. The stator assembly includes a metal ring (4b), which is fixedly mounted on the stationary end of the equipment by an insulating support (4a). The mover assembly includes a flexible metal sheet (4c), which is located on the outer surface of the telescopic shaft (1). The metal ring (4b) serves as a stationary plate with a fixed axial length. The temperature sensing module (5) consists of a temperature sensing left support (5c) and a temperature sensing right support (5d). A vertically extending temperature sensing support rail (5h) is provided between the temperature sensing left support (5c) and the temperature sensing right support (5d). A temperature sensing static insulating support (5b) is fixed on the upper part of the temperature sensing left support (5c) and the temperature sensing right support (5d). A temperature sensing static metal sheet (5a) is provided on the top surface of the temperature sensing static insulating support (5b). A movable temperature sensing moving insulating support (5e) is provided at the lower part of the temperature sensing left support (5c) and the temperature sensing moving insulating support (5e). A temperature sensing moving metal sheet (5f) is provided on the bottom surface of the temperature sensing moving insulating support (5e). The temperature sensing static insulating support (5b) and the temperature sensing moving insulating support (5e) are connected by multiple symmetrically distributed memory springs (5g). Temperature sensing support through holes (5k) are opened on both the temperature sensing left support (5c) and the temperature sensing right support (5d). The humidity sensing module (6) includes a humidity-sensing moving metal plate (6f) and a humidity-sensing stationary metal plate (6a) arranged parallel to each other. The humidity-sensing stationary metal plate (6a) is fixed by a humidity-sensing left support (6c) and a humidity-sensing right support (6d). A vertically extending humidity-sensing support rail (6h) is provided between the humidity-sensing left support (6c) and the humidity-sensing right support (6d). The humidity-sensing stationary metal plate (6a) is fixedly set on the bottom surface of the humidity-sensing stationary insulating support (6b). The humidity-sensitive sponge (6g) is set on the bottom surface of the humidity-sensing moving insulating support (6e). The humidity-sensing stationary insulating support (6b) is fixedly set... On the bottom surface of the humidity-sensitive sponge (6g), the humidity-sensitive sponge (6g) elastically connects the humidity-sensing moving insulating support (6e) and the humidity-sensing stationary insulating support (6b); the humidity-sensing moving insulating support (6e) is fixedly set on the bottom surface of the humidity-sensing moving metal sheet (6f), and the humidity-sensing moving insulating support (6e) is slidably fitted on the humidity-sensing support guide rail (6h). The humidity-sensing support guide rail (6h) provides a vertical moving track for the humidity-sensing moving insulating support (6e), while restricting its radial and rotational degrees of freedom. Humidity-sensing support through holes (6k) are opened on the humidity-sensing left support (6c) and the humidity-sensing right support (6d). The air pressure sensing module (7) includes a stationary air pressure sensing metal plate (7a) and a moving air pressure sensing metal plate (7f) arranged parallel to each other, a stationary air pressure sensing insulating support (7b), a moving air pressure sensing insulating support (7e), and an air chamber (7g). The stationary air pressure sensing metal plate (7a) is fixedly disposed on the bottom surface of the stationary air pressure sensing insulating support (7b); the moving air pressure sensing metal plate (7f) is fixedly disposed on the top surface of the moving air pressure sensing insulating support (7e); the stationary air pressure sensing insulating support (7b) is connected to the air pressure sensing unit by means of air pressure sensing. The left support (7c) and the right support (7d) are fixedly supported; the pressure sensing moving insulating support (7e) is connected to the left support (7c) and the right support (7d) through the pressure sensing support guide rail (7h); the pressure sensing support guide rail (7h) is located between the pressure sensing moving insulating support (7e) and the left support (7c) and the right support (7d); the air chamber (7g) is located between the pressure sensing stationary insulating support (7b) and the pressure sensing moving insulating support (7e). The self-vibration sensing module (8) includes a self-vibration sensing left support (8c) and a self-vibration sensing right support (8d). The inner walls of the self-vibration sensing left support (8c) and the self-vibration sensing right support (8d) are provided with vertically extending self-vibration sensing support rails (8h). A self-vibration sensing static insulating support (8b) is fixedly installed on the upper part of the self-vibration sensing support rail (8h). A self-vibration sensing static metal sheet (8a) is provided on the top surface of the self-vibration sensing static insulating support (8b). A self-vibration sensing moving insulating support (8e) is slidably provided inside the self-vibration sensing support rail (8h). A self-vibration sensing moving metal sheet (8f) is provided on the bottom surface of the self-vibration sensing moving insulating support (8e). The self-vibration sensing static insulating support (8b) and the self-vibration sensing moving insulating support (8e) are elastically connected by multiple symmetrically arranged self-vibration sensing springs (8g). The self-vibration sensing support rail (8h) provides a vertical moving track for the self-vibration sensing moving insulating support (8e) while restricting its horizontal degree of freedom.

2. The capacitive information sensing structure for industrial inspection according to claim 1, characterized in that: The balls of the left linear bearing (2) and the balls of the right linear bearing (2) form a clearance fit with the outer surface of the telescopic shaft (1) to restrict the telescopic shaft (1) to only perform linear reciprocating motion along the axial direction, while also restricting its radial runout.

3. The capacitive information sensing structure for industrial inspection according to claim 1, characterized in that: The protective rear seat (9) and the sensing protective cover (3) are fixed together by either a thread or a snap fastener to form a closed internal cavity.

4. The capacitive information sensing structure for industrial inspection according to claim 1, characterized in that: The metal ring (4b) and the flexible metal sheet (4c) maintain a preset radial gap, and the two are insulated from each other and form a variable area capacitor.

5. A capacitive information sensing structure for industrial inspection according to claim 4, characterized in that: The flexible metal sheet (4c) has a geometric shape with a gradually changing width on the axial unfolding surface of the telescopic shaft (1), and the width of the flexible metal sheet (4c) gradually changes along the extension direction of the telescopic shaft (1).

6. The capacitive information sensing structure for industrial inspection according to claim 1, characterized in that: The air chamber (7g) is a sealed cavity made of elastic material, which is filled with normal pressure gas. The stationary metal plate (7a) and the moving metal plate (7f) that sense air pressure are both located outside the air chamber (7g).

7. A capacitive information sensing structure for industrial inspection according to claim 1, characterized in that: It also includes a data correction and calculation algorithm running in the processing unit to eliminate the interference of environmental medium changes and mechanical vibration on capacitive displacement measurement. The algorithm steps are as follows: Step 1: Perform dynamic error correction based on the self-vibration sensing module (8). The system synchronously collects the main measurement capacitance signal of the displacement sensing module (4) and the vibration capacitance signal of the self-vibration sensing module (8). The processing unit monitors the capacitance fluctuation frequency and amplitude fed back by the self-vibration sensing module (8) in real time. Kalman filtering is used to remove noise components with the same frequency as the vibration from the original data of the displacement sensing module (4). At the same time, the original displacement value is reverse compensated according to the vibration quantization data to obtain the pure displacement signal after removing mechanical vibration interference. Step 2: Perform relative permittivity correction based on temperature sensing module (5), humidity sensing module (6) and air pressure sensing module (7). The system synchronously collects the main measurement capacitance signal of displacement sensing module (4) and the capacitance signals of temperature sensing module (5), humidity sensing module (6) and air pressure sensing module (7), and calculates the relative permittivity of air under the current environment using the corrected Ciddor formula. Step 3: Perform comprehensive calculation of geometric tolerances. The processing unit uses the high-precision absolute displacement data after noise reduction and environmental compensation as the basic data, and combines it with the continuous displacement data obtained during multi-point scanning. Through least squares fitting or spatial geometric algorithms, it calculates the geometric tolerances such as coaxiality and roundness of the measured hole or shaft, and finally outputs the corrected measurement report.

Images