Automatic testing method and system for thickness of coating layer on inner wall of pipe

Abstract

This application relates to the field of data processing technology and discloses a method and system for automatically testing the thickness of a coating on the inner wall of a tube. The method includes: initializing measurement parameters and generating a point plan using a liquid crystal display controller; using a fiber optic probe to identify a reference marker to obtain zero-position data; measuring the inner wall of an empty tube based on the zero-position data to obtain a data set B1; repositioning and measuring the coated quartz tube to obtain a data set B2; using B1 and B2 to calculate the film thickness distribution and generate a characteristic diagram; and finally, performing a uniformity assessment and generating a test report. This application achieves automated, high-precision measurement of the coating thickness on the inner wall of a quartz tube, and systematically processes and analyzes the measurement data to accurately assess the uniformity of the coating.

Description

Technical Field

[0001] The present application relates to the field of data processing, and in particular to a method and system for automatically testing the thickness of a coating layer on the inner wall of a pipe. Background Art

[0002] In the process of coating the inner wall of quartz tubes, measuring and controlling coating thickness is a critical quality control step. Existing measurement methods primarily include mechanical contact measurement and optical non-contact measurement. Mechanical contact measurement uses measuring instruments such as vernier calipers to obtain film thickness data by measuring the difference in the tube's inner diameter before and after coating. Optical non-contact measurement employs techniques such as beam ranging and optical interferometry to scan and measure the coating surface. These measurement methods are widely used in industrial production, playing a particularly important role in fields such as precision optical devices and semiconductor manufacturing.

[0003] However, existing measurement methods have significant limitations. Mechanical contact measurement can damage the coating surface, affecting measurement accuracy, and can only measure film thickness at the pipe opening, failing to obtain data deeper into the pipe. While optical non-contact measurement avoids contact damage, the measurement process lacks automation and standardization, and operator subjectivity can affect the consistency of measurement results. Furthermore, existing methods generally lack the ability to systematically process and analyze measurement data, making it difficult to accurately assess coating uniformity. Summary of the Invention

[0004] The present application provides an automatic testing method and system for the thickness of the coating layer on the inner wall of a tube, which is used to realize the automated and high-precision measurement of the thickness of the coating layer on the inner wall of a quartz tube, and to systematically process and analyze the measurement data to accurately evaluate the uniformity of the coating.

[0005] In the first aspect, the present application provides an automatic testing method for the thickness of the coating layer on the inner wall of a tube, and the automatic testing method for the thickness of the coating layer on the inner wall of a tube comprises: initializing and setting the measurement parameters through a liquid crystal display controller, generating a measurement point distribution scheme and measurement path planning data according to the angle interval and the displacement interval; identifying the position of the reference mark point on the surface of the quartz tube according to the optical fiber probe, and making the optical fiber spot coincide with the mark point through the cooperation of the rotating mechanism and the tube clamping device to obtain the zero-position reference data; based on the zero-position reference data, using the spectral confocal displacement sensor probe to scan and measure the inner wall of the empty tube, and Through the coordinated movement of the rotation mechanism and the automatic translation slide module, the empty tube distance value dataset B1 is obtained; based on the zero-position reference data, the coated quartz tube is repositioned, and the post-coating distance value is measured according to the measurement path planning data to obtain the post-coating distance value dataset B2; using the empty tube distance value dataset B1 and the post-coating distance value dataset B2, the film thickness distribution data is obtained through difference calculation, and a three-dimensional film thickness distribution characteristic diagram is generated; based on the film thickness distribution data, the film thickness uniformity is analyzed and evaluated, and a test report containing measurement parameters, original data, statistical results and quality assessment is generated.

[0006] In a second aspect, the present application provides an automatic testing system for the thickness of a coating layer on the inner wall of a pipe, the automatic testing system for the thickness of a coating layer on the inner wall of a pipe comprising:

[0007] A generation module is used to initialize the measurement parameters through the liquid crystal display controller and generate a measurement point distribution plan and measurement path planning data according to the angle interval and displacement interval;

[0008] The identification module is used to identify the position of the reference mark point on the surface of the quartz tube using the optical fiber probe, and to make the optical fiber spot coincide with the mark point through the cooperation of the rotating mechanism and the tube clamping device to obtain the zero reference data;

[0009] The measurement module is used to scan and measure the inner wall of the empty pipe using a spectral confocal displacement sensor probe based on the zero-position reference data, and obtain the empty pipe distance value data set B1 through the coordinated movement of the rotation mechanism and the automatic translation slide module;

[0010] A positioning module is used to reposition the coated quartz tube based on the zero reference data, measure the distance value after coating according to the measurement path planning data, and obtain the distance value data set B2 after coating;

[0011] A calculation module is used to obtain film thickness distribution data by difference calculation using the empty pipe distance value dataset B1 and the distance value dataset after coating B2, and generate a three-dimensional distribution characteristic diagram of film thickness;

[0012] The analysis module is used to analyze and evaluate the film thickness uniformity based on the film thickness distribution data, and generate a test report containing measurement parameters, raw data, statistical results and quality assessment.

[0013] In the technical solution provided by the present application, the measurement parameters are initialized and set through the liquid crystal display controller, and the measurement point distribution scheme and measurement path planning data are generated according to the angle interval and displacement interval, thereby realizing the intelligent control and optimization of the measurement process; the position of the reference mark point on the surface of the quartz tube is identified by the optical fiber probe, and the optical fiber spot is made to coincide with the mark point in conjunction with the rotating mechanism and the tube clamping device to obtain the zero-position reference data, thereby ensuring the accurate positioning of the measurement position; the spectral confocal displacement sensor probe is used to scan and measure the inner wall of the empty tube, and the coordinated movement of the rotating mechanism and the automatic translation slide module is combined to obtain the empty tube distance value data set B1, thereby realizing non-contact high-precision measurement; the coated quartz tube is re-positioned based on the zero-position reference data The distance value after coating is measured according to the measurement path planning data, and the distance value dataset B2 after coating is obtained, which ensures the consistency of the measurement position before and after coating; the empty tube distance value dataset B1 and the distance value dataset B2 after coating are used to obtain the film thickness distribution data through difference calculation, and a three-dimensional distribution characteristic diagram of the film thickness is generated, which realizes the visualization expression of the coating distribution; based on the film thickness distribution data, an intelligent algorithm is used to analyze and evaluate the film thickness uniformity, and a test report including measurement parameters, original data, statistical results and quality assessment is generated. In the process of collecting, processing and analyzing the measurement data, artificial intelligence algorithms are fully utilized for path planning optimization, data feature extraction and anomaly identification, which significantly improves the measurement efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 This is a schematic diagram of an embodiment of a method for automatically testing the thickness of a coating film on the inner wall of a pipe in an embodiment of the present application;

[0016] Figure 2 A schematic diagram of an automatic testing device in an embodiment of the present application;

[0017] Figure 3 A timing diagram showing the generation of a measurement point distribution scheme and measurement path planning data according to angle intervals and displacement intervals in an embodiment of the present application;

[0018] Figure 4This is a schematic diagram of an embodiment of an automatic testing system for the thickness of the coating layer on the inner wall of a pipe in an embodiment of the present application. DETAILED DESCRIPTION

[0019] The embodiments of the present application provide an automatic testing method and system for the thickness of the coating film on the inner wall of a pipe. The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products or devices.

[0020] For ease of understanding, the specific process of the embodiment of the present application is described below. Figure 1 In one embodiment of the present application, an automatic testing method for the thickness of the coating film on the inner wall of a pipe includes:

[0021] Step S101: Initialize measurement parameters through a liquid crystal display controller, and generate a measurement point distribution plan and measurement path planning data according to the angle interval and displacement interval;

[0022] Step S102: Using the optical fiber probe, the reference mark on the surface of the quartz tube is identified, and the optical fiber spot is aligned with the mark through the cooperation of the rotating mechanism and the tube clamping device to obtain zero reference data;

[0023] Step S103: Scan and measure the inner wall of the empty pipe using a spectral confocal displacement sensor probe based on the zero-position reference data, and obtain an empty pipe distance value dataset B1 through the coordinated movement of the rotation mechanism and the automatic translation slide module;

[0024] Step S104: reposition the coated quartz tube based on the zero reference data, measure the distance value after coating according to the measurement path planning data, and obtain a distance value data set B2 after coating;

[0025] Step S105: Using the empty tube distance value dataset B1 and the film-coated distance value dataset B2, the film thickness distribution data is obtained by difference calculation to generate a three-dimensional film thickness distribution characteristic diagram;

[0026] Step S106: Analyze and evaluate the film thickness uniformity based on the film thickness distribution data, and generate a test report including measurement parameters, original data, statistical results, and quality evaluation.

[0027] It is understood that the execution subject of this application can be an automatic testing system for the thickness of the coating film on the inner wall of the pipe, or a terminal or a server, which is not limited here. The embodiment of this application is described by taking the server as the execution subject as an example.

[0028] Specifically, the measurement parameters are initialized and set via the LCD controller. The LCD controller receives the angular resolution and repeatability parameters of the rotation mechanism, and simultaneously obtains the movement accuracy parameters of the automatic translation slide module. The angular interval is calculated based on the angular resolution parameters. The displacement interval is determined based on the movement accuracy parameters, and the appropriate axial sampling spacing is set based on the movement accuracy of the slide module. The LCD controller converts these interval parameters into a point distribution in a three-dimensional spatial coordinate system and constructs a measurement point matrix. Simultaneously, the measurement points are sorted according to the principle of the shortest spatial path to generate measurement path planning data.

[0029] The fiber optic probe begins to identify the position of a fiducial mark on the surface of the quartz tube. The fiber optic probe emits a beam of light of a specific wavelength, illuminating the surface of the quartz tube. As the quartz tube is secured by a tube clamp and rotated by a rotating mechanism, the fiber optic probe receives the reflected light signal. Due to its special surface treatment, the mark produces reflective properties that differ from those of ordinary surfaces, manifesting as a significant change in reflected light intensity. Threshold analysis of the reflected light intensity signal determines the precise angular position of the mark. The rotating mechanism then precisely rotates to the position where the fiber optic spot completely covers the mark. The angular and axial coordinate values at this point are recorded, forming the zero reference data. Based on this zero reference data, the spectral confocal displacement sensor probe begins scanning and measuring the inner wall of the empty tube. The white light emitted by the probe is separated by a dispersive element, resulting in different wavelengths of light exhibiting different focal plane positions in space. When the light strikes the surface being measured, only light of a specific wavelength is precisely focused and reflected back. By analyzing the peak wavelength in the returned spectrum, the distance from the probe to the surface can be accurately calculated. The rotating mechanism rotates the quartz tube according to the planned measurement path, while the automatic translation slide module controls the axial movement of the probe, achieving scanning measurement of the entire inner wall surface. The distance value and corresponding spatial position coordinates are recorded at each measurement point, forming the empty tube distance value dataset B1.

[0030] The measurement process of a coated quartz tube requires precise positioning. The coated tube is installed in a tube clamp, and the fiber optic probe re-locates the marking point. The rotation mechanism adjusts the tube to its initial angular position based on the zero-position reference data, ensuring consistent measurement positions before and after coating. Following the same measurement path planning data, the spectral confocal displacement sensor probe scans the coated inner wall. The spectral data collected by the probe undergoes the same processing flow to generate new distance values for each measurement point, forming the post-coating distance value dataset B2. The measurement points in the empty tube distance value dataset B1 and the post-coating distance value dataset B2 are mapped one-to-one using spatial coordinates. The distance difference between each pair of measurement points represents the film thickness at that point. The film thickness values of all measurement points constitute a discrete data set. A spatial interpolation algorithm is used to make these discrete points continuous, filling in the areas between the measurement points and generating continuous film thickness distribution data. This data is mapped to a three-dimensional coordinate system, with different shades of color representing different film thicknesses, creating an intuitive 3D film thickness distribution feature map.

[0031] The data is divided into several segments along the circumferential and axial directions, and statistical parameters such as the mean and standard deviation are calculated for each segment. These statistical parameters reflect the film thickness uniformity of each region. The uniformity assessment data is correlated with the original measurement parameters to identify the relationship between process parameters and film thickness distribution. By setting thresholds, outliers in the film thickness are identified and marked on a three-dimensional distribution graph. All measurement data, analysis results, and quality assessment information are integrated into the test report. For example, when measuring a 300 mm long epoxy-coated quartz tube, the circumferential measurement point spacing is set to 3°, and the axial spacing is set to 1.4 mm based on the slide rail module. Based on these parameter settings, the LCD controller automatically generates a measurement point matrix consisting of 120 circumferential points and 214 axial points. After the fiber optic probe recognizes the marked points, it measures the zero reference angle as 0 degrees and the axial coordinate as 10 mm. During the empty pipe measurement phase, the distance values corresponding to the peak wavelengths in the reflectance spectrum data collected by the spectral confocal displacement sensor probe constitute the empty pipe distance value dataset B1. In dataset B2, measured again after coating, the distance value at each point decreases accordingly. Subtracting the two data sets yields film thickness data that clearly demonstrates the coating's distribution characteristics. The resulting 3D distribution feature map visually demonstrates the film's uniformity.

[0032] In the embodiment of the present application, the measurement parameters are initialized and set through the liquid crystal display controller, and the measurement point distribution scheme and measurement path planning data are generated according to the angle interval and displacement interval, thereby realizing intelligent control and optimization of the measurement process; the position of the reference mark point on the surface of the quartz tube is recognized by the optical fiber probe, and the optical fiber spot is made to coincide with the mark point in conjunction with the rotation mechanism and the tube clamping device to obtain the zero-position reference data, thereby ensuring the accurate positioning of the measurement position; the spectral confocal displacement sensor probe is used to scan and measure the inner wall of the empty tube, and the coordinated movement of the rotation mechanism and the automatic translation slide module is combined to obtain the empty tube distance value data set B1, thereby realizing non-contact high-precision measurement; the coated quartz tube is repositioned based on the zero-position reference data, The post-coating distance value is measured according to the measurement path planning data to obtain the post-coating distance value dataset B2, ensuring the consistency of the measurement positions before and after coating; the film thickness distribution data is obtained by difference calculation using the empty tube distance value dataset B1 and the post-coating distance value dataset B2, and a three-dimensional distribution characteristic diagram of the film thickness is generated, realizing the visual expression of the coating distribution; based on the film thickness distribution data, an intelligent algorithm is used to analyze and evaluate the film thickness uniformity, and a test report containing measurement parameters, original data, statistical results and quality assessment is generated. In the process of collecting, processing and analyzing the measurement data, artificial intelligence algorithms are fully utilized for path planning optimization, data feature extraction and anomaly identification, which significantly improves the measurement efficiency and accuracy.

[0033] In a specific embodiment, the process of executing step S101 may specifically include the following steps:

[0034] (1) Read the clamping parameters of the pipe clamping device through the LCD controller to form an initialization parameter set;

[0035] (2) The LCD controller collects the angular resolution parameters and repeatability parameters of the rotating mechanism;

[0036] (3) Import the movement accuracy parameters of the automatic translation slide module into the LCD controller;

[0037] (4) Generate angle intervals based on angle resolution parameters and generate displacement intervals based on movement accuracy parameters;

[0038] (5) Construct a measurement coordinate matrix based on the angle interval and displacement interval to generate a measurement point distribution plan;

[0039] (6) Sort the measurement sequence according to the spatial optimal path based on the measurement point distribution plan to obtain the measurement path planning data.

[0040] Specifically, if Figure 2Figure 2 shows a schematic diagram of the automatic testing equipment in an embodiment of the present application. The LCD controller reads the clamping parameters of the tube clamping device. The tube clamping device is a mechanical structure specifically used to secure a quartz tube. Its clamping parameters include the clamping status data (such as alarm data) and position data of the quartz tube detected by the fiber optic probe. These parameters are transmitted to the LCD controller via the tube clamping device's data interface. The controller integrates these data to form an initialization parameter set. Each parameter in the initialization parameter set is accompanied by a corresponding unit identifier and valid value range to facilitate subsequent parameter verification and call-up. The LCD controller then collects key parameters of the rotating mechanism. The rotating mechanism is integrated with the tube clamping device and is responsible for driving the quartz tube for precise rotation. The angular resolution parameter defines the minimum angular change that the rotating mechanism can detect. The repeatability parameter indicates the deviation range when the rotating mechanism repeatedly locates the same angular position. These two parameters are transmitted to the LCD controller via the rotating mechanism's communication interface and recorded in a dedicated parameter table.

[0041] like Figure 3 As shown, it is a timing diagram of generating the measurement point distribution scheme and measurement path planning data according to the angle interval and displacement interval in an embodiment of the present application. The movement accuracy parameters of the automatic translation slide module are imported into the liquid crystal display controller. The automatic translation slide module is a high-precision linear motion component, and its movement accuracy parameters determine the positioning accuracy of the axial measurement point. The movement accuracy parameter value is 10 microns, which represents the minimum control unit of the slide when performing linear motion. After the data format conversion, the parameter is stored in the parameter database of the liquid crystal display controller. Based on these basic parameters obtained, the liquid crystal display controller starts to calculate the measurement interval. The generation of the angle interval is based on the angle resolution parameter. Taking into account the stability of the measurement, the actual angle interval is set to an integer multiple of the angle resolution. Similarly, the displacement interval is also calculated based on the movement accuracy parameter to ensure that each measurement point can be accurately positioned by the slide module.

[0042] After generating the measurement intervals, the LCD controller begins constructing the measurement coordinate matrix. In a cylindrical coordinate system, each measurement point is uniquely identified by its angular and axial coordinates. By combining the angular and displacement intervals, a two-dimensional array is formed, where each element corresponds to a measurement point on the inner wall of the quartz tube. This array forms a complete measurement point distribution plan. The LCD controller uses a spatial optimal path algorithm to sort all measurement points based on the shortest total path. This algorithm takes into account the time costs of rotational and linear motion and determines the optimal measurement sequence by calculating the spatial distances between adjacent measurement points. The sorted sequence of measurement points constitutes the measurement path planning data.

[0043] For example, when measuring a quartz tube with an inner diameter of 20 mm and a length of 100 mm, the tube clamping device transmits these dimensional parameters to the LCD controller. The actual angular interval is set to 3° to ensure measurement stability. Taking into account the circumference of the quartz tube, 120 measurement points are evenly distributed along the circumference. The automatic translation slide module sets the axial measurement interval to 1.4 mm and arranges 71 measurement points over a measurement length of 100 mm. This creates a 120 x 71 measurement point matrix. The spatial optimal path algorithm calculates the spatial distance from each measurement point to its adjacent points and arranges a measurement sequence with the shortest total path. For example, when measuring between two adjacent axial positions, the angular change is minimized to reduce the time consumed by the rotational motion.

[0044] In a specific embodiment, the process of executing step S102 may specifically include the following steps:

[0045] (1) The quartz tube is axially positioned by the tube clamping device to generate axial positioning parameters;

[0046] (2) Importing the axial positioning parameters into the control unit of the rotating mechanism to generate a rotating scanning sequence;

[0047] (3) Scan the surface of the quartz tube by emitting a light beam through the optical fiber probe and collect the reflection signal of the reference mark point;

[0048] (4) Analyze the intensity of the reflected signal and extract the position characteristic value of the reference mark point;

[0049] (5) The rotating mechanism adjusts the rotation angle according to the position characteristic value until the optical fiber spot coincides with the marking point;

[0050] (6) The rotation angle and axial positioning parameters are fused to generate zero-position reference data.

[0051] Specifically, the tube clamp, as a precision mechanical device, uses a multi-point centering mechanism to ensure the axial concentricity of the quartz tube. The centering mechanism contains multiple sets of pressure sensors that monitor the magnitude and distribution of the clamping force in real time. The axial positioning parameters are calculated according to the following formula:

[0052]

[0053] in: Indicates the axial positioning parameter; Indicates the force reading at the jth pressure point; represents the moment coefficient of the jth pressure point; Indicates the quartz tube height compensation factor; represents the centering quality factor; Indicates the number of pressure measurement points.

[0054] After the axial positioning parameters are transmitted to the control unit of the rotating mechanism through the data interface, the control unit generates a rotation scanning sequence according to the following function:

[0055]

[0056] in: represents the rotation angular velocity function; represents the angular velocity amplitude coefficient; represents the angular acceleration coefficient; represents the phase compensation coefficient; represents the dynamic response coefficient; Indicates the scan time parameter.

[0057] The fiber optic probe collects reflected signals during the scanning process, and the reflected signal intensity distribution follows the following model:

[0058]

[0059] in: Indicates the reflected signal strength; Indicates the baseline signal strength; , Indicates the center coordinates of the marker point; represents the spot radius coefficient; represents the surface reflection coefficient; Represents the surface roughness parameter.

[0060] During the reflection signal strength analysis, the following formula is used to extract the position characteristic value:

[0061]

[0062] in: Indicates the feature value of the marker point position; Indicates the signal gain correction factor; Indicates the angle deviation value; Indicates the standard angle parameter. When the optical fiber spot coincides with the mark point, the reflected signal intensity reaches its peak. The rotation angle at this time is fused with the axial positioning parameter to generate the zero reference data:

[0063]

[0064] in: Indicates zero reference data; represents the fusion coefficient; Indicates the rotation angle value; Represents the time correction function.

[0065] For example, when measuring and positioning a quartz tube coated with epoxy resin, the clamping device collects clamping force data using multiple pressure sensors. The force data collected by each pressure sensor is multiplied by the corresponding torque coefficient. This data is then combined with the tube's height compensation factor and centering quality factor to calculate the axial positioning parameters. After receiving the axial positioning parameters, the rotation mechanism's control unit generates a scanning sequence based on the rotational angular velocity function to control the tube's rotational motion. The optical fiber probe emits a light beam that scans the tube's surface. When it reaches a marked point, the reflected signal intensity changes significantly. The signal processing unit analyzes the reflected signal and extracts a positional characteristic value. The rotation mechanism continuously adjusts the rotation angle based on this characteristic value until the optical fiber spot completely overlaps the marked point. Finally, the rotation angle value at the time of overlap is fused with the axial positioning parameters to generate zero-position reference data.

[0066] In a specific embodiment, the process of executing step S103 may specifically include the following steps:

[0067] (1) The spectral confocal displacement sensor probe determines the initial measurement position based on the zero-position reference data and generates the detection beam parameters;

[0068] (2) The detection beam parameters are synchronously converted through the rotation mechanism and the automatic translation slide module to obtain the motion control signal;

[0069] (3) The white light emitted by the spectral confocal displacement sensor probe is spectrally separated by a dispersion element to obtain reflection spectrum data;

[0070] (4) Extract the confocal peak of the reflectance spectrum data and generate a spectral shift response curve;

[0071] (5) Analyze the distance to the empty pipe wall at the measurement position based on the spectral displacement response curve to form point distance data;

[0072] (6) The point distance data is aligned with the motion control signal to obtain the air traffic control distance value dataset B1.

[0073] Specifically, the non-contact measurement device utilizes the principle of dispersion to spatially separate light of different wavelengths, thereby achieving accurate distance measurement. When the probe determines the initial measurement position based on zero-reference data, it needs to generate beam parameters. Probe beam parameters are a combination of factors, including the wavelength range, intensity distribution, and focusing characteristics of the light source. These parameters are precisely adjusted by the light source control unit to form a probe beam suitable for measuring the inner wall of the quartz tube. The probe's light source emitter adjusts the intensity and focal position based on the measurement range. A rotation mechanism and an automatic translation slide module work together to control the spatial position of the probe beam. The rotation mechanism controls the angular movement of the quartz tube, while the automatic translation slide module controls the axial displacement. When converting the probe beam parameters into specific motion commands, the kinematic characteristics of the two moving components must be considered. Their motion speeds must be coordinated to ensure a stable measurement signal at each measurement point. The motion control signal generated by this synchronous conversion process contains position, velocity, and acceleration information.

[0074] The white light emitted by the spectral confocal displacement sensor probe has a continuous spectral distribution. After passing through a dispersive element (such as a diffraction grating or prism), this light of different wavelengths is separated into distinct optical paths. The design of the dispersive element must consider spectral resolution and light intensity loss. The separated wavelengths form a series of discrete focal points in space, each corresponding to a specific measurement distance. When these beams strike the inner wall of the quartz tube, only light of a specific wavelength is precisely focused and reflected. The reflected spectral data received by the probe contains distance information.

[0075] Processing reflectance spectrum data requires signal preprocessing, including noise removal and baseline correction. A peak detection algorithm is then used to extract the confocal peak. A spectral curve is generated for each measurement point, with the strongest peak corresponding to the optimal focus position. By fitting the peak data from a series of measurement points, a spectral shift response curve is generated. This curve reflects the relationship between wavelength and measurement distance.

[0076] Based on the spectral shift response curve obtained through calibration, the data at each measurement position is resolved for distance. The resolution process takes into account the geometric parameters of the optical path system and the optical properties of the material. For smooth surfaces such as the inner wall of a quartz tube, the reflected signal is ideal, which helps improve measurement accuracy. The spatial position of each measurement point and the corresponding distance value constitute the point distance data. This data also includes the timestamp information of the measurement moment. The point distance data is matched with the motion control signal. The registration process needs to consider the delay of the measurement system and the dynamic characteristics of the moving parts. Each distance measurement value needs to accurately correspond to the corresponding angular position and axial position. The registered data constitute the empty pipe distance value dataset B1, which fully records the three-dimensional profile information of the inner wall of the empty pipe.

[0077] For example, when measuring the inner wall of a quartz tube, the spectral confocal displacement sensor probe is moved to its initial position based on the zero-position reference data. The white light emitted by the probe passes through the dispersion element, resulting in a continuous spectrum with a wavelength range from 400nm to 800nm. Each wavelength corresponds to a different focal plane position, constituting a measurement range. The rotating mechanism rotates at a fixed angular velocity, taking a measurement every time it rotates a certain angle. At the same time, the slide module moves axially at a set spacing. At each measurement point, the spectral data processing unit receives the reflected spectrum, extracts the peak wavelength, and converts it into a distance value. These measurement data are aligned with the angular and displacement data of the mechanical movement to form a complete data set describing the morphology of the inner wall of the empty tube.

[0078] In a specific embodiment, the process of executing step S104 may specifically include the following steps:

[0079] (1) Place the coated quartz tube in a tube clamping device and generate a positioning reference signal from the zero reference data;

[0080] (2) According to the positioning reference signal, the rotation mechanism is driven to align the angle and form the repositioning angle data;

[0081] (3) Decompose the path based on the measured path planning data to generate a displacement sequence signal;

[0082] (4) The spectrum of the inner wall of the quartz tube after coating is collected by using a spectral confocal displacement sensor probe to obtain the spectrum data after coating;

[0083] (5) Perform spatial registration on the post-coating spectral data and the repositioning angle data to obtain the post-coating displacement value;

[0084] (6) Correlate and map the displacement value after coating with the displacement sequence signal to form the distance value data set B2 after coating.

[0085] Specifically, during the measurement of a coated quartz tube, the coated tube must be repositioned in the clamping device. The clamping device uses a multi-point pressure sensor to ensure the axial positioning accuracy of the tube. It re-detects and identifies the zero reference data based on the marking points, generating a new positioning reference signal. This positioning reference signal includes both angular and axial position values.

[0086] The generation process of relocation angle data follows the following formula:

[0087]

[0088] in: Represents repositioning angle data; Represents the reading of the kth angle sensor; represents the angle weight coefficient; represents the temperature compensation factor; Indicates the axial offset correction value; represents the time attenuation coefficient; represents the measurement time; q represents the number of angle sensors. The rotary mechanism is precisely aligned based on the repositioning angle data, establishing a mapping between spatial coordinates and angular positions at each measurement point. Next, the measurement path planning data is broken down into a series of specific displacement instructions. These instructions form a displacement sequence signal, which guides the movement of the slide module. The displacement sequence signal takes into account control requirements at three levels: acceleration, velocity, and position, ensuring a smooth measurement process.

[0089] The spectral confocal displacement sensor probe begins measuring the inner wall of the coated quartz tube. The white light emitted by the probe is separated by a dispersion element, forming a series of spatial focal planes. When the light strikes the coated surface, the reflected spectrum changes accordingly due to the coating's thickness and optical properties. These changes are recorded in the post-coating spectral data, which contains distance information from the coating surface. Spatial registration of the post-coating spectral data with the repositioned angle data is a critical step. This registration process must account for the measurement system's time delay characteristics and the dynamic characteristics of the mechanical motion. By establishing a timestamp correspondence, each spectral measurement is accurately matched to the corresponding angular position, resulting in a post-coating displacement value. This displacement value reflects the actual distance from the coating surface to the probe.

[0090] The post-coating displacement values are mapped to the displacement sequence signals. This mapping process establishes a corresponding relationship between the spatial position of the measurement point and the actual measured value. This relationship is recorded in the post-coating distance value dataset B2, which serves as an important data basis for subsequent calculations of the film thickness.

[0091] For example, when measuring a quartz tube coated with epoxy resin, the installation torque data is read by the multi-point pressure sensor of the tube clamping device and combined with the zero-position reference data to generate a positioning reference signal. The rotation mechanism adjusts the angular position based on this signal until it is aligned with the reference position. The measurement path planning data is converted into specific motion instructions to control the axial movement of the slide module. At each measurement point, the spectral confocal displacement sensor probe emits white light and receives the reflected signal. Due to the presence of the coating, the characteristics of the reflected spectrum are different from those when measuring an empty tube. The data processing unit aligns this spectral data with the angular position information to obtain the actual distance value for each measurement point. All measurement data are integrated into the post-coating distance value dataset B2.

[0092] In a specific embodiment, the process of executing step S105 may specifically include the following steps:

[0093] (1) Match the empty pipe distance value dataset B1 with the post-coating distance value dataset B2 to form a paired data matrix;

[0094] (2) Perform data synchronization calibration on the paired data matrix to generate a distance difference sequence;

[0095] (3) The distance difference sequence is spatially reconstructed according to the coordinate information of the measurement points to obtain the initial distribution data of the film thickness;

[0096] (4) Continuously process the initial distribution data of the film thickness through interpolation operation to form the film thickness distribution data;

[0097] (5) Construct a three-dimensional spatial coordinate system based on the film thickness distribution data to generate spatial distribution data;

[0098] (6) Convert the spatial distribution data into graphic display data to form a three-dimensional distribution characteristic diagram of the film thickness.

[0099] Specifically, data processing starts with the point-to-point matching of the empty tube distance value dataset B1 and the distance value dataset after coating B2. Each dataset contains angular coordinates, axial coordinates and corresponding distance values. The point-to-point matching process is based on spatial coordinates, and the measurement point data at the same position are paired to form a paired data matrix containing two sets of distance values. The pairing process is carried out through a coordinate mapping algorithm to ensure that each measurement point can find an accurate correspondence. The paired data matrix contains measurement data of a large number of discrete points, and data synchronization calibration is required. The calibration process takes into account factors such as the systematic error, temperature drift and mechanical deformation of the measurement system. The calibrated data is obtained by subtraction operation to obtain a distance difference sequence, which represents the initial value of the film thickness at each measurement point. The calculation of the distance difference needs to take into account the nonlinear characteristics of the measurement system and compensate the original data.

[0100] The distance difference sequence is combined with the spatial coordinate information of the measurement points to generate the initial distribution data of the film thickness through a spatial reconstruction algorithm. The spatial reconstruction process converts the discrete measurement points into a structured data grid, with each grid point carrying a corresponding film thickness value. The reconstruction algorithm needs to deal with the uneven distribution of measurement points to ensure that the reconstructed data can accurately reflect the actual distribution characteristics of the film layer. In order to obtain a continuous film thickness distribution, the initial distribution data of the film thickness is interpolated. The interpolation process uses a three-dimensional spline interpolation algorithm to generate a smooth transition region between known measurement points. The interpolation algorithm needs to consider the local characteristics of the data to avoid abnormal fluctuations at the boundaries. The interpolated data forms a continuous film thickness distribution, which fully describes the film characteristics of the entire pipe wall surface.

[0101] The film thickness distribution data is mapped into a three-dimensional coordinate system to generate spatial distribution data. The coordinate system is based on the axis of the quartz tube. Angular coordinates represent circumferential position, axial coordinates represent longitudinal position, and radial coordinates represent film thickness. Each point in the spatial distribution data contains complete position information and the corresponding film thickness value.

[0102] Convert spatial distribution data into visual graphical displays. This conversion utilizes a 3D rendering algorithm, which uses different shades of color to represent variations in film thickness. The rendering algorithm takes into account display parameters such as viewing angle and lighting to generate intuitive 3D distribution maps of film thickness.

[0103] For example, when measuring a quartz tube coated with a thermal insulation coating, raw data consisting of two thousand circumferential measurement points and one thousand axial measurement points were obtained. When measuring the empty tube, the distance value from the probe to the tube wall was recorded at each point, forming data set B1. The distance values at the corresponding positions were also obtained for the measurement after coating, forming data set B2. The point matching algorithm compares the coordinate information and pairs the measurement points at the same position in the two sets of data to form a complete paired data matrix. Data synchronization calibration eliminates systematic errors in the measurement process and obtains an accurate sequence of distance differences. These difference data are reconstructed into gridded distribution data, and then an interpolation algorithm is used to fill the areas between the measurement points to generate a continuous film thickness distribution. These data are converted into a three-dimensional feature map, which clearly shows the thickness distribution characteristics of the coating.

[0104] In a specific embodiment, the process of executing step S106 may specifically include the following steps:

[0105] (1) Perform circumferential and axial segmental statistics on the film thickness distribution data to obtain regional statistical parameters;

[0106] (2) Construct a film thickness uniformity distribution map based on regional statistical parameters and generate uniformity evaluation data;

[0107] (3) Correlation analysis is performed on the uniformity evaluation data and the measurement parameters to form correlation data;

[0108] (4) Identify abnormal points in film thickness through correlation data and generate abnormal area marking information;

[0109] (5) Integrate the abnormal area marking information with the original data to obtain statistical results;

[0110] (6) Compare and analyze the statistical results with the quality assessment standards and generate a test report.

[0111] Specifically, the film thickness distribution data is segmented and statistically processed. The circumferential segmentation is based on a fixed angle, such as every 30 degrees is divided into a segment; the axial segmentation is divided at equal intervals along the length of the tube, such as every 10 mm is a segment. Statistical indicators such as the average value, standard deviation, maximum value, and minimum value are calculated in each segment to form regional statistical parameters. These parameters reflect the thickness distribution characteristics of the coating in the local area. When constructing a film thickness uniformity distribution map based on regional statistical parameters, the statistical parameters of each segment need to be standardized. The standardization process takes into account the relative positional relationship of different regions and performs normalization conversion on the data. The converted data forms uniformity evaluation data, which reflects the uniformity of the distribution of the coating thickness in the overall space.

[0112] Uniformity assessment data and measurement parameters are closely related. These include process parameters such as rotational speed, axial travel speed, and measurement point density. Correlation analysis reveals the influence of these parameters on coating uniformity. Multivariate correlation analysis is used to establish a mapping between these parameters and generate correlation data. This correlation data provides the basis for identifying outliers in film thickness. Outlier identification utilizes a statistical threshold method to identify measurement points that deviate from the normal distribution range. The identification process comprehensively considers the statistical characteristics of the local region and the global distribution characteristics to generate marker information for the outlier region. This marker information includes the spatial location and degree of deviation of the outlier.

[0113] Abnormal region marking information needs to be integrated with the original measurement data. The integration process associates the specific parameters of the abnormal region with the corresponding points in the original measurement data to form a complete statistical result. The statistical result contains a complete description of normal and abnormal regions, providing data support for quality assessment.

[0114] The statistical results are compared with pre-defined quality assessment criteria. These criteria define specific indicators such as the permissible range of coating thickness and uniformity requirements. This comparative analysis generates a detailed test report containing comprehensive measurement data, statistical analysis results, and quality assessment conclusions.

[0115] For example, when measuring and evaluating the anti-reflection coating on an optical-grade quartz tube, the tube wall is divided into 12 circumferential segments (one segment every 30 degrees) and 20 axial segments (one segment every 10 mm). Statistical parameters for the coating thickness are calculated within each segment, such as the average thickness of a particular segment being 15 microns with a standard deviation of 0.5 microns. This data constitutes a regional statistical parameter set. Normalization is then performed to generate evaluation data reflecting overall uniformity. Correlating this evaluation data with process parameters during measurement reveals a clear correlation between rotation speed and coating uniformity. Based on this correlation, appropriate thresholds are set to identify outliers that deviate from the normal range. The locations of these outliers are recorded and integrated with the raw data to generate comprehensive statistical results. Finally, the statistical results are compared with quality standards, and a test report containing all measurement and analysis data is generated, providing a basis for process improvement.

[0116] The above describes the automatic testing method for the thickness of the inner wall coating film of the pipe in the embodiment of the present application. The following describes the automatic testing system for the thickness of the inner wall coating film of the pipe in the embodiment of the present application. Figure 4 In one embodiment of the present application, an automatic testing system for the thickness of the coating film on the inner wall of a pipe includes:

[0117] The generating module 201 is used to initialize the measurement parameters through the liquid crystal display controller, and generate the measurement point distribution scheme and measurement path planning data according to the angle interval and the displacement interval;

[0118] Identification module 202, for identifying the position of a reference mark on the surface of the quartz tube using the optical fiber probe, and aligning the optical fiber spot with the mark through the cooperation of the rotating mechanism and the tube clamping device to obtain zero reference data;

[0119] The measurement module 203 is used to scan and measure the inner wall of the empty pipe using a spectral confocal displacement sensor probe based on the zero-position reference data, and obtain an empty pipe distance value data set B1 through the coordinated movement of the rotation mechanism and the automatic translation slide module;

[0120] The positioning module 204 is used to reposition the coated quartz tube based on the zero reference data, measure the distance value after coating according to the measurement path planning data, and obtain the distance value data set B2 after coating;

[0121] The calculation module 205 is used to obtain the film thickness distribution data by difference calculation using the empty tube distance value dataset B1 and the film-coated distance value dataset B2, and generate a three-dimensional distribution characteristic diagram of the film thickness;

[0122] The analysis module 206 is used to analyze and evaluate the film thickness uniformity based on the film thickness distribution data, and generate a test report including measurement parameters, original data, statistical results and quality evaluation.

[0123] Through the coordinated cooperation of the above components, the measurement parameters are initialized and set through the LCD display controller, and the measurement point distribution plan and measurement path planning data are generated according to the angle interval and displacement interval, thus realizing the intelligent control and optimization of the measurement process; the optical fiber probe is used to identify the position of the reference mark point on the surface of the quartz tube, and the rotating mechanism and the tube clamping device are used to make the optical fiber spot coincide with the mark point to obtain the zero-position reference data, thus ensuring the accurate positioning of the measurement position; the spectral confocal displacement sensor probe is used to scan and measure the inner wall of the empty tube, and the coordinated movement of the rotating mechanism and the automatic translation slide module is combined to obtain the empty tube distance value data set B1, thus realizing non-contact high-precision measurement; the coated quartz tube is re-measured based on the zero-position reference data. With the new positioning, the distance value after coating is measured according to the measurement path planning data, and the distance value data set B2 after coating is obtained, which ensures the consistency of the measurement position before and after coating; the film thickness distribution data is obtained by difference calculation using the empty tube distance value data set B1 and the distance value data set after coating B2, and a three-dimensional distribution characteristic diagram of the film thickness is generated, realizing the visual expression of the coating distribution; based on the film thickness distribution data, an intelligent algorithm is used to analyze and evaluate the uniformity of the film thickness, and a test report containing measurement parameters, original data, statistical results and quality assessment is generated. In the process of collecting, processing and analyzing the measurement data, artificial intelligence algorithms are fully utilized for path planning optimization, data feature extraction and anomaly identification, which significantly improves the measurement efficiency and accuracy.

[0124] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An automatic testing method for the thickness of the coating layer on the inner wall of a pipe, characterized in that: The automatic testing method for the thickness of the coating layer on the inner wall of the pipe comprises: Initialize the measurement parameters through the LCD controller, and generate the measurement point distribution plan and measurement path planning data according to the angle interval and displacement interval; The optical fiber probe is used to identify the position of the reference mark on the surface of the quartz tube. The rotation mechanism and the tube clamping device are used to make the optical fiber spot coincide with the mark to obtain the zero reference data. Based on the zero-position reference data, a spectral confocal displacement sensor probe is used to scan and measure the inner wall of the empty pipe, and an empty pipe distance value data set B1 is obtained through the coordinated movement of a rotation mechanism and an automatic translation slide module, including: the spectral confocal displacement sensor probe determines an initial measurement position according to the zero-position reference data and generates detection beam parameters; the rotation mechanism and the automatic translation slide module synchronously convert the detection beam parameters to obtain a motion control signal; the white light emitted by the spectral confocal displacement sensor probe is spectrally separated by a dispersion element to obtain reflection spectrum data; the reflection spectrum data is confocal peak extracted to generate a spectral displacement response curve; the empty pipe wall distance at the measurement position is analyzed according to the spectral displacement response curve to form point distance data; the point distance data is point-aligned with the motion control signal to obtain the empty pipe distance value data set B1; Based on the zero-position reference data, the quartz tube after coating is repositioned, and the distance value after coating is measured according to the measurement path planning data to obtain the distance value data set B2 after coating; Using the empty tube distance value dataset B1 and the film-coated distance value dataset B2, the film thickness distribution data is obtained by difference calculation, and a three-dimensional distribution characteristic diagram of the film thickness is generated; Based on the film thickness distribution data, the film thickness uniformity is analyzed and evaluated, and a test report is generated that includes measurement parameters, raw data, statistical results, and quality assessment.

2. The automatic testing method for the thickness of the coating film on the inner wall of a pipe according to claim 1, characterized in that: The method of initializing the measurement parameters by the liquid crystal display controller and generating the measurement point distribution scheme and measurement path planning data according to the angle interval and the displacement interval includes: Reading the clamping parameters of the pipe clamping device through the liquid crystal display controller to form an initialization parameter set; The liquid crystal display controller collects the angular resolution parameters and the repeatability parameters of the rotating mechanism; Importing the movement accuracy parameters of the automatic translation slide module into the liquid crystal display controller; generating the angle interval based on the angle resolution parameter and generating the displacement interval based on the movement accuracy parameter; Constructing a measurement coordinate matrix according to the angle interval and the displacement interval to generate the measurement point distribution scheme; The measurement sequence is sorted according to the spatial optimal path based on the measurement point distribution scheme to obtain the measurement path planning data.

3. The automatic testing method for the thickness of the coating film on the inner wall of a pipe according to claim 1, characterized in that: The method of identifying the position of the reference mark point on the surface of the quartz tube using the optical fiber probe, and making the optical fiber spot coincide with the mark point through the cooperation of the rotating mechanism and the tube clamping device to obtain zero-position reference data includes: The tube clamping device performs axial positioning on the quartz tube to generate axial positioning parameters; Importing the axial positioning parameters into the control unit of the rotation mechanism to generate a rotation scanning sequence; The optical fiber probe emits a light beam to scan the surface of the quartz tube and collects the reflection signal of the reference mark point; Performing intensity analysis on the reflected signal to extract position characteristic values of the reference mark points; The rotating mechanism adjusts the rotation angle according to the position characteristic value until the optical fiber spot coincides with the marking point; The rotation angle and the axial positioning parameter are fused to generate the zero position reference data.

4. The automatic testing method for the thickness of the coating film on the inner wall of a pipe according to claim 1, characterized in that: The coated quartz tube is repositioned based on the zero reference data, and the distance value after coating is measured according to the measurement path planning data to obtain the distance value data set B2 after coating, including: Placing the coated quartz tube in the tube clamping device, and generating a positioning reference signal based on the zero position reference data; driving the rotating mechanism to perform angle alignment according to the positioning reference signal to form repositioning angle data; Performing path decomposition based on the measurement path planning data to generate a displacement sequence signal; The spectrum of the inner wall of the quartz tube after coating is collected by the spectral confocal displacement sensor probe to obtain the spectrum data after coating; Performing spatial registration on the post-coating spectral data and the repositioning angle data to obtain a post-coating displacement value; The post-coating displacement value is correlated and mapped with the displacement sequence signal to form the post-coating distance value data set B2.

5. The automatic testing method for the thickness of the coating film on the inner wall of a pipe according to claim 1, characterized in that: The method uses the empty tube distance value dataset B1 and the film-coated distance value dataset B2 to obtain the film thickness distribution data through difference calculation and generate a three-dimensional film thickness distribution characteristic diagram, including: Perform point-to-point matching on the empty pipe distance value dataset B1 and the post-coating distance value dataset B2 to form a pairing data matrix; Performing data synchronization calibration on the paired data matrix to generate a distance difference sequence; The distance difference sequence is spatially reconstructed according to the measurement point coordinate information to obtain the initial distribution data of the film thickness; Performing continuous processing on the initial distribution data of the film thickness by interpolation operation to form film thickness distribution data; Constructing a three-dimensional spatial coordinate system based on the film thickness distribution data to generate spatial distribution data; The spatial distribution data is converted into graphic display data to form the three-dimensional distribution characteristic diagram of the film thickness.

6. The automatic testing method for the thickness of the coating film on the inner wall of a pipe according to claim 1, characterized in that: The film thickness uniformity is analyzed and evaluated based on the film thickness distribution data, and a test report containing measurement parameters, raw data, statistical results and quality assessment is generated, including: Performing circumferential and axial segmental statistics on the film thickness distribution data to obtain regional statistical parameters; constructing a film thickness uniformity distribution map based on the regional statistical parameters to generate uniformity evaluation data; Performing correlation analysis on the uniformity evaluation data and the measurement parameters to form correlation data; Identify abnormal film thickness points using the correlation data to generate abnormal area marking information; Integrating the abnormal region marking information with the original data to obtain the statistical result; The test report is generated by comparing and analyzing the statistical results with the quality assessment standards.

7. An automatic testing system for the thickness of a coating film on the inner wall of a pipe, used to implement the automatic testing method for the thickness of a coating film on the inner wall of a pipe as claimed in any one of claims 1 to 6, characterized in that: The automatic testing system for the thickness of the coating layer on the inner wall of the pipe comprises: A generation module is used to initialize the measurement parameters through the liquid crystal display controller and generate a measurement point distribution plan and measurement path planning data according to the angle interval and displacement interval; The identification module is used to identify the position of the reference mark point on the surface of the quartz tube using the optical fiber probe, and to make the optical fiber spot coincide with the mark point through the cooperation of the rotating mechanism and the tube clamping device to obtain the zero reference data; A measurement module is configured to scan and measure the inner wall of an empty pipe using a spectral confocal displacement sensor probe based on zero-position reference data, and obtain an empty pipe distance value data set B1 through the coordinated movement of a rotation mechanism and an automatic translation slide module. The module comprises: determining an initial measurement position by the spectral confocal displacement sensor probe based on the zero-position reference data and generating detection beam parameters; synchronously converting the detection beam parameters through the rotation mechanism and the automatic translation slide module to obtain a motion control signal; spectrally separating the white light emitted by the spectral confocal displacement sensor probe through a dispersion element to obtain reflection spectrum data; performing confocal peak extraction on the reflection spectrum data to generate a spectral displacement response curve; parsing the empty pipe wall distance at the measurement position based on the spectral displacement response curve to form point distance data; and performing point registration between the point distance data and the motion control signal to obtain the empty pipe distance value data set B1. A positioning module is used to reposition the coated quartz tube based on the zero reference data, measure the distance value after coating according to the measurement path planning data, and obtain the distance value data set B2 after coating; A calculation module is used to obtain film thickness distribution data by difference calculation using the empty pipe distance value dataset B1 and the distance value dataset after coating B2, and generate a three-dimensional distribution characteristic diagram of film thickness; The analysis module is used to analyze and evaluate the film thickness uniformity based on the film thickness distribution data, and generate a test report containing measurement parameters, raw data, statistical results and quality assessment.

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