Bidirectional display and operation laser diameter measuring instrument and method

Abstract

The invention discloses a bidirectional display and operation laser diameter measuring instrument and method, and relates to the technical field of laser diameter measuring instruments, and the instrument comprises a coefficient calibration module which is used for generating a first leakage strip and a second leakage strip, and determining an equivalent absorption coefficient based on the first leakage strip and the second leakage strip; the reference recording module is used for recording a reference datum and a reference distance of the reference pixel; the leakage field calculation module is used for calculating leakage field estimation based on the along-wall propagation distance field, the equivalent absorption coefficient, the reference datum and the reference distance; and the diameter measurement correction module is used for forming a corrected diameter measurement section based on the leakage field estimation and the original diameter measurement section, and determining the target diameter of the measured object based on the corrected diameter measurement section. According to the invention, the stability and repeatability of measurement are improved.

Description

Technical Field

[0001] This invention relates to the field of laser diameter measuring instrument technology, and more particularly to a laser diameter measuring instrument and method with bidirectional display and operation. Background Technology

[0002] In the inspection of narrow, elongated cavities such as wind turbine towers, shafts, and pipelines, precise measurement of the internal geometric dimensions is often required to assess the component's manufacturing accuracy and service condition. Laser diameter gauges, as non-contact inspection devices, are widely used for measuring the internal diameter of these cavities due to their good environmental adaptability and high response speed. However, in environments such as towers or shafts, the internal walls often develop a continuous thin water film due to temperature and humidity differences. When an infrared beam grazing into this wall surface, the water film creates a light-guiding phenomenon along the wall, causing some energy to leak back into the measurement system through the window edge, resulting in false optical responses. Furthermore, multi-source lighting in confined spaces and alternating personnel operations cause dynamic changes in the incident direction of the measurement window and the wall reflection conditions, leading to random deviations in the diameter measurement results and severely affecting measurement stability and repeatability.

[0003] In existing technologies, traditional laser diameter measurement methods typically assume that the optical path near the measurement window is an ideal direct or diffuse reflection model, ignoring the interference from wall-guided light and leakage caused by a thin water film on the wall. Furthermore, they often rely on unidirectional display or unidirectional data output, making it impossible to verify or correct measurement errors in real time. When faced with virtual edges formed by wall-guided light and window leakage induced by a thin water film, this method easily misinterprets the virtual signal as the real boundary, resulting in systematic errors such as overestimating or underestimating the diameter. Especially in scenarios requiring bidirectional operation, existing laser diameter gauges struggle to achieve data interaction and error self-calibration between the measuring and display ends, limiting the real-time performance and reliability of on-site measurements. The single-sided display and operation make it inconvenient for production staff to view real-time measurement data. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing laser diameter measuring instruments, which are difficult to achieve data interaction and error self-calibration between the measuring end and the display end, thus limiting the real-time performance and reliability of on-site measurements. Therefore, this invention proposes a laser diameter measuring instrument and method with bidirectional display and operation.

[0005] To address the problems existing in the prior art, the present invention adopts the following technical solution: A two-way display and operation laser diameter gauge, comprising: Preferably, generating the first leakage band and the second leakage band includes: Turn off the main diameter measuring transmitter and apply auxiliary grazing light to the wall of the cavity to be measured at the first grazing angle and the second grazing angle in sequence. The intensity distribution of the leakage strip corresponding to the first grazing angle and the second grazing angle is collected by the receiving linear array in the edge region of the measurement window to obtain the first leakage strip and the second leakage strip.

[0006] Preferably, determining the equivalent absorption coefficient based on the first leakage band and the second leakage band includes: Calculate the critical angle based on the refractive index of air and the refractive index of water film; If both the first and second grazing angles are greater than the critical angle, then the wall-guided light condition is satisfied; otherwise, the wall-guided light condition is not satisfied. Under the condition that the light guide along the wall is satisfied, a difference operation is performed on the first leakage strip and the second leakage strip to obtain the leakage signature; Based on the geometric calibration relationship between the measurement window and the wall, the distance of the leaked light from the incident point to each pixel position along the wall is calculated, and the distance field along the wall is generated. Logarithmic linear fitting was performed on the leakage signature and the propagation distance field along the wall to obtain the equivalent absorption coefficient.

[0007] Preferably, recording the reference reference and reference distance of the reference pixel includes: Turn on the main diameter measuring transmitter and acquire the original diameter measuring profile of the object under test in a linear array scanning mode. The original diameter measuring profile is the infrared received signal intensity at the pixel coordinates. In the set of pixels corresponding to the original diametrical profile, the reference pixel closest to the leak is selected according to the geometric calibration relationship between the measurement window and the wall. The received intensity of the reference pixel during the main measurement period is recorded as a reference benchmark, and the reference distance corresponding to the reference pixel is recorded simultaneously.

[0008] Preferably, the leakage field estimate is calculated based on the wall propagation distance field, equivalent absorption coefficient, reference base, and reference distance, including: The distance difference along the wall is calculated by dividing the distance field propagating along the wall by the reference distance. Multiplying the equivalent absorption coefficient and the difference in distance along the wall yields a linear combination of exponential terms; By performing an exponential operation on the linear combination of exponential terms, the exponential decay factor is obtained. The leakage field estimate is obtained by multiplying the reference baseline and the exponential decay factor.

[0009] Preferably, the process of generating a corrected calibrated calibrated profile based on the leakage field estimation and the original calibrated profile includes: The leakage field estimate is processed by pixel-by-pixel expansion to obtain the pixel-by-pixel leakage intensity; A pixel-by-pixel cancellation operation is performed on the original diameter measurement profile and the pixel-by-pixel leakage intensity to obtain the corrected diameter measurement profile.

[0010] Preferably, determining the target diameter of the object being measured based on the calibrated diametrical profile includes: The maximum value is obtained by iterating through the calibration diameter profile; The half-height value is obtained by proportionally converting the bright-field platform value; Based on the half-height value, linear interpolation search is performed on the left descending edge and the right ascending edge of the calibrated diameter profile to obtain the left edge pixel coordinates and the right edge pixel coordinates. The difference between the coordinates of the right edge pixels and the coordinates of the left edge pixels is calculated to obtain the pixel spacing difference. The target diameter of the object under test is obtained by proportionally converting the pixel pitch difference and pixel scale coefficient.

[0011] Preferably, the reference pixel closest to the leak is selected based on the geometric calibration relationship between the measurement window and the wall surface, including: The propagation distance along the wall of each pixel relative to the leak opening is determined based on the pre-established geometric calibration relationship between the measurement window and the wall surface, and the pixel with the smallest propagation distance along the wall is selected as the reference pixel closest to the leak opening.

[0012] To address the above problems, the present invention also provides a bidirectional display and operation method for diameter measurement, the method comprising: S1. Generate a first leakage band and a second leakage band, and determine the equivalent absorption coefficient based on the first leakage band and the second leakage band; S2. Record the reference reference and reference distance of the reference pixel; S3. Calculate the leakage field estimate based on the wall propagation distance field, equivalent absorption coefficient, reference benchmark and reference distance; S4. Based on the leakage field estimation and the original diameter measurement profile, a corrected diameter measurement profile is generated, and the target diameter of the measured object is determined based on the corrected diameter measurement profile. S5. Provide a two-way interface for displaying and interacting with the target diameter.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention introduces an infrared strip differential processing mechanism under wall-guided light conditions to achieve quantitative extraction of the non-uniform energy propagation phenomenon caused by weak liquid film leakage. After the critical angle is determined to meet the total reflection condition, pixel-level differential operations are performed on the first and second leakage strips to form a leakage signature map. Combining the geometric calibration relationship between the measurement window and the wall surface and the pixel coordinate system, a wall-propagation distance field is constructed. Monotonicity verification and distance difference calculation are performed to quantify the absorption effect of each pixel in the wall propagation direction, thereby extracting the local equivalent absorption coefficient and providing basic data support for subsequent leakage field estimation and actual size calibration.

[0014] 2. This invention further improves the accuracy of target boundary positioning by constructing a corrected diameter measurement profile and using a platform interval half-height algorithm to perform linear interpolation on the edge pixels of the measured object. First, the original diameter measurement profile and the leakage estimation field are fused and corrected to generate a one-dimensional bright field platform profile. Then, based on this platform profile, the platform mean and half-height threshold are calculated, and linear interpolation search is performed on the left and right edges respectively to obtain the edge pixel coordinates. Then, the pixel scale coefficient is combined for numerical conversion to finally obtain the actual infrared diameter of the target object. This effectively avoids the edge misjudgment problem caused by speckle, blur or reflection in traditional diameter measurement and improves the stability and repeatability of the system measurement. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 A functional block diagram of a two-way display and operation laser diameter measuring instrument provided in an embodiment of the present invention; Figure 2 This is a flowchart illustrating a bidirectional display and operation method for diameter measurement according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the display mechanism of a bidirectional display and operation diameter measuring instrument according to an embodiment of the present invention. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] Example: This example provides a laser diameter measuring instrument with bidirectional display and operation. See [link to example]. Figure 1 Specifically, including: The coefficient calibration module is used to generate a first leakage band and a second leakage band, and to determine the equivalent absorption coefficient based on the first leakage band and the second leakage band; In an embodiment of the present invention, generating a first leakage band and a second leakage band includes: Turn off the main diameter measuring transmitter and apply auxiliary grazing light to the wall of the cavity to be measured at the first grazing angle and the second grazing angle in sequence. The intensity distribution of the leakage strip corresponding to the first grazing angle and the second grazing angle is collected by the receiving linear array in the edge region of the measurement window to obtain the first leakage strip and the second leakage strip.

[0018] Specifically, the main diameter measuring transmitter is a transmitting device used to emit laser diameter measuring signals to directly acquire the internal diameter measurement data of the cavity under test; the first grazing angle and the second grazing angle are two different angles formed by the auxiliary grazing light incident on the wall of the cavity under test and the normal to the wall surface. The angle values ​​need to be adapted to the optical properties of the thin water film medium on the wall surface to induce total internal reflection of the light; the wall surface of the cavity under test is the inner wall structure of narrow cavities such as wind turbine towers or shafts, and its surface is prone to condensation due to environmental temperature differences, forming a continuous thin water film; the auxiliary grazing light is auxiliary infrared light used to detect the light guiding characteristics along the wall surface, and its function is to excite the light guiding effect along the wall surface of the thin water film; the receiving linear array is an optical signal receiver composed of multiple photoelectric detection units arranged linearly. The receiving device converts the incident light signal into a collectable electrical signal; the edge region of the measuring window is the spatial region adjacent to the wall of the cavity to be measured, which is the main area where light propagating along the wall leaks into the diameter measuring instrument; the intensity distribution of the leakage strip is the distribution pattern formed by the light intensity of the leaked light after being guided along the wall and collected by the receiving linear array, as the position of the detection unit changes; the first leakage strip is the intensity distribution of the leakage strip collected by the receiving linear array in the edge region of the measuring window under the illumination of the auxiliary grazing light corresponding to the first grazing angle; the second leakage strip is the intensity distribution of the leakage strip collected by the receiving linear array in the edge region of the measuring window under the illumination of the auxiliary grazing light corresponding to the second grazing angle.

[0019] Specifically, firstly, the control module of the diameter measuring instrument outputs a shutdown signal to the main diameter measuring transmitter, causing the main diameter measuring transmitter to stop emitting laser diameter measuring signals; then, the auxiliary light source module is controlled to adjust the emission angle to a first grazing angle, and the auxiliary light source module is activated to emit auxiliary grazing light towards the wall of the cavity under test at this first grazing angle, maintaining the emission state of the auxiliary grazing light until the end of a preset first irradiation duration; next, the auxiliary light source module is controlled to adjust the emission angle to a second grazing angle, and the auxiliary light source module is activated to emit auxiliary grazing light towards the wall of the cavity under test at this second grazing angle, maintaining the emission state of the auxiliary grazing light until the end of a preset second irradiation duration; during the process of the auxiliary light source module emitting auxiliary grazing light at the first grazing angle, the control... The receiving linear array is in working condition, and its detection area is aligned with the edge of the measurement window. The receiving linear array continuously collects the light intensity signal in this area. The collected light intensity signals are arranged according to the detection unit positions of the receiving linear array to form a leakage strip intensity distribution corresponding to the first grazing angle, which is denoted as the first leakage strip. During the process of the auxiliary light source module emitting auxiliary grazing light at the second grazing angle, the detection area of ​​the receiving linear array is kept aligned with the edge of the measurement window. The receiving linear array continuously collects the light intensity signal in this area. The collected light intensity signals are arranged according to the detection unit positions of the receiving linear array to form a leakage strip intensity distribution corresponding to the second grazing angle, which is denoted as the second leakage strip.

[0020] In embodiments of the present invention, determining the equivalent absorption coefficient based on the first leakage band and the second leakage band includes: Calculate the critical angle based on the refractive index of air and the refractive index of water film; Specifically, first, the air refractive index is obtained. This can be done by consulting a standard air refractive index table or by using environmental parameters (such as temperature and air pressure) and the corresponding air refractive index calculation formula to obtain the air refractive index under the current environment. Next, the water film refractive index is obtained. This can be done by measuring the refractive index of a thin water film on the wall of the cavity being measured using an optical measurement device, or by looking up the water film refractive index from a preset water film refractive index calibration curve based on the water film's temperature and impurities. Then, according to the calculation formula for the critical angle of total internal reflection, the obtained air refractive index and water film refractive index are substituted into the formula: Critical angle = arcsin(air refractive index / water film refractive index). The arcsine operation is then performed by the mathematical calculation module to obtain the specific value of the critical angle, thus completing the calculation of the critical angle.

[0021] If both the first and second grazing angles are greater than the critical angle, then the wall-guided light condition is satisfied; otherwise, the wall-guided light condition is not satisfied. Under the condition that the light guide along the wall is satisfied, a difference operation is performed on the first leakage strip and the second leakage strip to obtain the leakage signature; Specifically, the control module first retrieves the calculated critical angle and the preset values ​​of the first and second grazing angles. It then compares the first grazing angle with the critical angle, and subsequently compares the second grazing angle with the critical angle. If both the first and second grazing angles are greater than the critical angle, the control module determines that the wall-guided light condition is met. If either grazing angle is less than the critical angle, the control module determines that the wall-guided light condition is not met. The logic behind this step is that only when the grazing angle is greater than the critical angle can the auxiliary grazing light undergo total internal reflection at the interface between the water film and air, thus achieving wall-guided light. This ensures that subsequent calculations based on the leakage strip are effective. The physical basis is as follows: After the control module outputs the judgment result that the wall-guided light conditions are met, the control module retrieves the intensity distribution data corresponding to the first and second leakage strips that have been collected. For each detection unit position of the receiving linear array, the intensity value of the first leakage strip and the intensity value of the second leakage strip at that position are calculated. After the difference calculation is completed for all detection unit positions, the distribution formed by these difference data is the leakage signature. The logic of this step is that both the first and second leakage strips contain common-mode interference such as ambient background light. Differential operation can eliminate such interference, highlight the specific characteristics of the wall-guided light leakage signal, and provide reliable data for subsequent parameter fitting.

[0022] Specifically, the air refractive index is a physical quantity that affects the speed of light propagation in air; its value represents the ratio of the speed of light in air to the speed of light in a vacuum. The water film refractive index is a physical quantity that affects the speed of light propagation in a thin water film formed on the wall of the cavity being tested; its value represents the ratio of the speed of light in the water film to the speed of light in a vacuum. The critical angle is the angle of incidence at which the refracted ray propagates precisely along the interface between the water film and air when light travels from the optically denser medium of water film to the optically less dense medium of air; it is used to determine whether light undergoes a refraction reaction. The critical angle for total internal reflection; the wall-guided light condition refers to the condition under which the auxiliary grazing light can undergo total internal reflection in the water film on the wall of the cavity under test and propagate along the wall. Whether it is satisfied or not is determined by the relationship between the grazing angle and the critical angle; the differential operation is a mathematical operation method that calculates the difference between the light intensity data corresponding to the first leakage strip and the second leakage strip position by position; the leakage signature is the result obtained by performing a differential operation on the first leakage strip and the second leakage strip. It can characterize the leakage characteristics of the light propagating along the wall as a function of the propagation distance and is the basic data for subsequent analysis of leakage interference.

[0023] Based on the geometric calibration relationship between the measurement window and the wall, the distance of the leaked light from the incident point to each pixel position along the wall is calculated, and the distance field along the wall is generated. Logarithmic linear fitting was performed on the leakage signature and the propagation distance field along the wall to obtain the equivalent absorption coefficient.

[0024] Specifically, the geometric calibration relationship between the measurement window and the wall refers to the relative size and orientation relationship between the spatial position of the measurement window and the spatial position of the wall of the cavity under test, which is determined in advance by geometric measurement methods. It includes information such as the vertical distance from the measurement window to the wall and the projection range of the edge of the measurement window on the wall. The incident point refers to the initial position of the auxiliary grazing incident light when it is incident on the wall of the cavity under test. The distance propagated along the wall to each pixel position refers to the path length of the leaked light from the incident point, after propagating along the wall of the cavity under test, to the wall position corresponding to each detector pixel of the receiving linear array. The distance field of propagation along the wall refers to the distance distribution data set formed by sorting the distances of the propagation paths along the wall corresponding to each pixel position of the receiving linear array according to the pixel arrangement order. Logarithmic linear fitting refers to the fitting method of converting one of the two sets of data into logarithmic form and constructing the linear correlation between the two sets of data through mathematical operations. The equivalent absorption coefficient refers to the parameter characterizing the degree of light intensity attenuation with propagation distance during the propagation of the leaked light along the wall. It reflects the intensity of the comprehensive absorption and scattering of the leaked light by the wall and the thin water film.

[0025] Specifically, the control module first retrieves the pre-stored geometric calibration relationship between the measurement window and the wall surface. This relationship includes information such as the projected coordinates of the measurement window edge on the wall surface and the vertical distance from the measurement window to the wall surface. Then, combined with the emission angle of the auxiliary grazing incident light, it calculates the coordinates of the incident point on the wall surface when the auxiliary grazing incident light is incident on the wall surface according to the geometric calibration relationship. Subsequently, for each pixel of the receiving linear array, it determines the wall surface position coordinates corresponding to the detection area of ​​that pixel according to the geometric calibration relationship, and then calculates the path length extending from the incident point coordinates to the wall surface position coordinates along the contour trajectory of the wall surface. This path length is the distance that the leaked light travels from the incident point along the wall to the pixel position. After the propagation distance along the wall corresponding to each pixel is calculated, the sequence number of each pixel and its corresponding propagation distance along the wall are sequentially associated and integrated to generate the propagation distance field along the wall. After the propagation distance field along the wall is generated, the control module retrieves the obtained leakage signature and the above-mentioned propagation distance field along the wall. First, the intensity value corresponding to each detection unit in the leakage signature is transformed by natural logarithm to obtain the leakage signature data in logarithmic form. Then, the least squares method is used to linearly fit the leakage signature data in logarithmic form with the distance data in the propagation distance field along the wall to construct a linear equation with the propagation distance along the wall as the independent variable and the leakage signature in logarithmic form as the dependent variable. The absolute value of the slope of this linear equation is the equivalent absorption coefficient.

[0026] The reference recording module is used to record the reference reference and reference distance of the reference pixel; In embodiments of the present invention, recording the reference reference and reference distance of the reference pixel includes: Turn on the main diameter measuring transmitter and acquire the original diameter measuring profile of the object under test in a linear array scanning mode. The original diameter measuring profile is the infrared received signal intensity at the pixel coordinates. In the set of pixels corresponding to the original diametrical profile, the reference pixel closest to the leak is selected according to the geometric calibration relationship between the measurement window and the wall. In an embodiment of the present invention, selecting the reference pixel closest to the leak point based on the geometric calibration relationship between the measurement window and the wall surface includes: The propagation distance along the wall of each pixel relative to the leak opening is determined based on the pre-established geometric calibration relationship between the measurement window and the wall surface, and the pixel with the smallest propagation distance along the wall is selected as the reference pixel closest to the leak opening.

[0027] Specifically, the control module first outputs a start signal to the main diameter measuring transmitter, causing it to emit a laser diameter measuring signal. Simultaneously, it controls the receiving linear array to scan the measurement area corresponding to the object being measured, converting the infrared signal at each pixel coordinate into an electrical signal and recording its intensity value. These intensity values ​​are integrated according to the pixel coordinates to form the original diameter measuring profile. The logic of this step is to acquire the infrared received signal intensity through linear array scanning, providing basic data for subsequent inner diameter measurement and interference correction. Then, the pre-stored geometric calibration relationship between the measurement window and the wall surface is retrieved, and combined with the pixel set corresponding to the original diameter measuring profile, a reference pixel selection operation is performed. The logic of this step is... To select a pixel close to the leak opening as a reference to obtain the reference signal of the leaking light, in an embodiment of the present invention, the specific implementation of this selection operation is as follows: based on the pre-established geometric calibration relationship between the measurement window and the wall, the propagation distance along the wall of each pixel in the pixel set relative to the leak opening is calculated, and then the propagation distances along the wall corresponding to all pixels are numerically compared. The pixel with the smallest value is selected as the reference pixel closest to the leak opening. The logic of this step is to accurately determine the pixel closest to the leak opening through the quantitative calculation and comparison of the propagation distance along the wall, ensuring that the reference pixel can effectively reflect the reference signal characteristics of the leaking light, and providing a reliable target pixel for subsequent recording of the reference benchmark and reference distance.

[0028] The received intensity of the reference pixel during the main measurement period is recorded as a reference benchmark, and the reference distance corresponding to the reference pixel is recorded simultaneously.

[0029] Specifically, the main diameter measuring transmitter is a device that emits laser diameter measuring signals to obtain data related to the inner diameter of the object being measured. Its emitted infrared signal can cover the measurement area corresponding to the object being measured. The linear array scanning method involves the receiving linear array sequentially acquiring pixel-by-pixel optical signals from the measurement area corresponding to the object being measured according to a preset time sequence. This method allows for the acquisition of continuous signal distribution data. The object being measured refers to narrow cavity structures such as wind turbine towers or shafts that require inner diameter measurement, with its inner wall serving as the target area for measurement. The original diameter measuring profile is the distribution of infrared light signal intensity in pixel coordinates, acquired by the receiving linear array through linear array scanning. It reflects the infrared signal reception status of the corresponding area of ​​the object being measured. Pixel coordinates are the position identifiers of each detector pixel in the receiving linear array; different pixel coordinates correspond to different detection positions of the receiving linear array. The infrared received signal intensity is the intensity value of the electrical signal obtained after photoelectric conversion of the incident infrared signal by each pixel of the receiving linear array, and it is related to the light intensity of the incident infrared light. The pixel set is the overall set of all detector pixels covered by the original diameter measuring profile. The measurement system comprises: all detection positions corresponding to the original diameter measurement profile; the geometric calibration relationship between the measurement window and the wall surface, which is the relative size and orientation relationship between the spatial position of the measurement window and the spatial position of the wall surface of the measured object, determined in advance through geometric measurement, including information such as the distance from the measurement window to the wall surface; the leakage port, which is the area where the leakage light propagating along the wall enters the measurement window in the region adjacent to the edge of the measurement window and the wall surface of the measured object; the reference pixel, which is the detection pixel closest to the leakage port selected from the pixel set corresponding to the original diameter measurement profile, used to provide reference data for the leakage light signal; the main diameter measurement period, which is the time interval during which the main diameter measurement transmitter completes a complete laser diameter measurement signal transmission and the receiving linear array completes the corresponding data acquisition; the received intensity, which is the signal intensity value obtained by the reference pixel after photoelectric conversion of the incident infrared signal within the main diameter measurement period; the reference reference, which is the value corresponding to the received intensity of the reference pixel within the main diameter measurement period, used as the reference data for subsequent calculation of the leakage field; and the reference distance, which is the propagation distance along the wall corresponding to the reference pixel, i.e., the path length of the leakage light from the incident point along the wall to the wall surface position corresponding to the reference pixel.

[0030] Specifically, the time interval corresponding to the main diameter measurement cycle is first determined. This interval is the complete period from the start of laser diameter measurement signal transmission by the main diameter measurement transmitter to the completion of the acquisition of the corresponding original diameter measurement profile by the receiving linear array. Within this main diameter measurement cycle, the electrical signal intensity value output by the selected reference pixel is read, stored, and used as a reference benchmark. Simultaneously, the propagation distance along the wall corresponding to the reference pixel, calculated in advance based on the geometric calibration relationship between the measurement window and the wall, is retrieved and stored synchronously as the reference distance corresponding to the reference benchmark. The logic of this step is that the reference benchmark is the signal intensity benchmark value of the leaked light at the reference pixel position, and the reference distance is the propagation path length along the wall corresponding to that pixel. The synchronous recording of the two provides the basic parameters for subsequent derivation of the leaked light intensity at each pixel position by combining the equivalent absorption coefficient. This is a necessary data preparation step for realizing leakage interference correction of the original diameter measurement profile.

[0031] The leakage field calculation module is used to calculate leakage field estimates based on the wall propagation distance field, equivalent absorption coefficient, reference benchmark, and reference distance. In embodiments of the present invention, the leakage field estimation is calculated based on the wall propagation distance field, the equivalent absorption coefficient, the reference base, and the reference distance, including: The distance difference along the wall is calculated by dividing the distance field propagating along the wall by the reference distance. Multiplying the equivalent absorption coefficient and the difference in distance along the wall yields a linear combination of exponential terms; By performing an exponential operation on the linear combination of exponential terms, the exponential decay factor is obtained. Specifically, first, the linear combination of the obtained exponential terms is retrieved, which is the result of multiplying the equivalent absorption coefficient by the distance difference along the wall; then, an exponential operation with the natural constant as the base is performed on the linear combination of the exponential terms, converting the value of each linear combination term into the corresponding exponential operation result; finally, these exponential operation results are sorted according to the corresponding pixel positions, and the resulting set is the exponential decay factor.

[0032] The leakage field estimate is obtained by multiplying the reference baseline and the exponential decay factor.

[0033] Specifically, the wall-propagation distance field refers to the set of distance distributions formed by the path lengths of the leaked light corresponding to each pixel of the receiving linear array from the incident point to the corresponding wall position, arranged according to the pixel arrangement; the reference distance refers to the path length of the leaked light corresponding to the reference pixel from the incident point to the corresponding wall position; the wall-propagation distance difference refers to the numerical difference between the path lengths corresponding to each pixel in the wall-propagation distance field and the reference distance; the equivalent absorption coefficient is a parameter characterizing the degree of light intensity attenuation with propagation distance during the propagation of leaked light along the wall, reflecting the overall effect of the wall and thin water film on the leaked light. The terms are: intensity of absorption; linear combination of exponential terms, which is the numerical result obtained by multiplying the equivalent absorption coefficient by the distance difference along the wall; exponential attenuation factor, which is the numerical value obtained by exponentially operating the linear combination of exponential terms, reflecting the light intensity attenuation ratio when the leaked light propagates along the wall from the reference pixel position to the corresponding pixel position; reference reference, which is the infrared received signal intensity of the reference pixel within the main measurement period; and leakage field estimation, which is the set of values ​​obtained by multiplying the reference reference by the exponential attenuation factor, corresponding to the estimated value of the leaked light signal intensity at each pixel position of the receiving linear array.

[0034] Specifically, when the leaked light propagates along the wall of the cavity under test, its light intensity will exhibit an exponential decay characteristic with the propagation distance due to the absorption and scattering effects of the wall and the thin water film. This characteristic conforms to the attenuation law in the process of light propagation, that is, the light intensity after propagation is equal to the product of the initial light intensity and an exponential function with the negative value of the product of the absorption coefficient and the propagation distance as the exponent. The distance field along the wall corresponds to the total propagation distance of the leaked light at each pixel position, and the reference distance corresponds to the propagation distance of the leaked light at the reference pixel position. The difference between the two distances is the additional propagation distance of the leaked light at each pixel position relative to the reference pixel position. The equivalent absorption coefficient is a parameter characterizing the degree of light intensity attenuation during the propagation along the wall. Multiplying it by the distance difference along the wall, the resulting linear combination of exponential terms is the quantification value of the attenuation effect corresponding to the additional propagation distance. Performing an exponential operation on this linear combination term, the resulting exponential attenuation factor is the proportion of light intensity attenuation of the leaked light from the reference pixel position to the corresponding pixel position. The reference reference is the initial light intensity of the leaked light at the reference pixel position. Multiplying it by the exponential attenuation factor, the result is the leakage light intensity at each pixel position, which is the leakage field estimate. This calculation process perfectly matches the physical law of light intensity attenuation during the propagation of leaked light along the wall, thus accurately obtaining the leakage field estimate.

[0035] The diameter measurement correction module is used to generate a corrected diameter measurement profile based on the leakage field estimation and the original diameter measurement profile, and to determine the target diameter of the object being measured based on the corrected diameter measurement profile. In embodiments of the present invention, generating a corrected diameter measurement profile based on leakage field estimation and the original diameter measurement profile includes: The leakage field estimate is processed by pixel-by-pixel expansion to obtain the pixel-by-pixel leakage intensity; A pixel-by-pixel cancellation operation is performed on the original diameter measurement profile and the pixel-by-pixel leakage intensity to obtain the corrected diameter measurement profile.

[0036] Specifically, pixel-by-pixel unpacking refers to the process of breaking down the leakage field estimate into individual pixels of the receiving linear array, so that each pixel corresponds to an independent leakage light intensity data. Pixel-by-pixel leakage intensity refers to the leakage light signal intensity value corresponding to each pixel position of the receiving linear array after pixel-by-pixel unpacking. Pixel-by-pixel cancellation operation refers to the operation of subtracting the infrared received signal intensity corresponding to that pixel in the original diameter measurement profile from the pixel-by-pixel leakage intensity for each pixel of the receiving linear array. Corrected diameter measurement profile refers to the infrared received signal intensity distribution obtained after pixel-by-pixel cancellation operation, which has eliminated the interference of leakage light signals and can more accurately reflect the effective laser diameter measurement signal situation corresponding to the measured object.

[0037] Specifically, the control module first retrieves the obtained leakage field estimate, which includes the estimated leakage light signal intensity values ​​corresponding to each pixel of the receiving linear array. Then, according to the pixel arrangement order of the receiving linear array, the leakage light intensity data of each pixel corresponding to the leakage field estimate is extracted separately, so that each pixel corresponds one-to-one with a unique leakage light intensity value, completing the pixel-by-pixel unfolding process. The leakage light intensity value corresponding to each pixel obtained after this processing is the pixel-by-pixel leakage intensity. Next, the control module retrieves the original diameter measurement profile, which is the infrared received signal intensity at the pixel coordinates acquired by the receiving linear array in a linear array scanning manner. For each pixel of the receiving linear array, the infrared received signal intensity value corresponding to that pixel in the original diameter measurement profile is subtracted from the leakage light intensity value corresponding to that pixel in the pixel-by-pixel leakage intensity, completing the cancellation operation for that pixel. After the cancellation operation for all pixels of the receiving linear array is completed, the values ​​obtained by the operation for each pixel are integrated according to the pixel arrangement order, and the new infrared received signal intensity distribution formed is the corrected diameter measurement profile.

[0038] In embodiments of the present invention, determining the target diameter of the object being measured based on a calibrated diametrical profile includes: The maximum value is obtained by iterating through the calibration diameter profile; The half-height value is obtained by proportionally converting the bright-field platform value; Based on the half-height value, linear interpolation search is performed on the left descending edge and the right ascending edge of the calibrated diameter profile to obtain the left edge pixel coordinates and the right edge pixel coordinates. Specifically, the calibration diameter profile refers to the intensity distribution of the effective laser diameter measurement signal of the measured object obtained after eliminating leakage light signal interference through pixel-by-pixel cancellation operation; the traversal maximum value processing refers to the operation of reading the signal intensity value corresponding to each pixel in the calibration diameter profile one by one according to the pixel arrangement order of the receiving linear array, and comparing these values ​​to determine the maximum value; the bright field plateau value refers to the maximum signal intensity value in the calibration diameter profile obtained through traversal maximum value processing, which corresponds to the stable received intensity of the infrared signal when the measured area is unobstructed; the scaling operation refers to the operation of multiplying the bright field plateau value by a preset scaling factor, which is usually selected as half; the half height value refers to the value obtained through scaling, which is half the bright field plateau value. One-third; the left descending edge refers to the edge corresponding to the transition region in the calibrated diameter profile where the signal intensity gradually decreases from the bright field plateau value to the low intensity region; the right ascending edge refers to the edge corresponding to the transition region in the calibrated diameter profile where the signal intensity gradually rises from the low intensity region back to the bright field plateau value; linear interpolation search refers to the operation of determining the pixel position corresponding to the half-height value between adjacent pixels of the left descending edge or the right ascending edge based on the relationship of signal intensity change; the left edge pixel coordinates refer to the pixel position identifier corresponding to the half-height value of the left descending edge of the calibrated diameter profile obtained through linear interpolation search; the right edge pixel coordinates refer to the pixel position identifier corresponding to the half-height value of the right ascending edge of the calibrated diameter profile obtained through linear interpolation search.

[0039] Specifically, the control module retrieves the obtained calibration diameter profile and, according to the pixel arrangement of the receiving linear array, reads the infrared received signal intensity value corresponding to each pixel in the calibration diameter profile one by one. Simultaneously, it compares the read values ​​in real time, comparing the current read value with the recorded maximum value. If the current read value is larger, the recorded maximum value is updated until all pixel values ​​have been read and compared. The final recorded maximum value is the bright-field plateau value. The control module then retrieves the obtained bright-field plateau value and a preset scaling factor (which is half the value). The bright-field plateau value is multiplied by this scaling factor, and the result is the half-height value. The control module first determines the left descending edge region of the calibration diameter profile; this region is where the signal intensity transitions from the bright-field plateau value to the low-intensity region in the calibration diameter profile. The left edge pixel coordinates are determined by finding two adjacent pixels within the calibration profile. One pixel has a signal strength greater than half the height, while the other has a signal strength less than half the height. Based on the coordinates of these two pixels and their corresponding signal strengths, the pixel position corresponding to the half height is calculated using linear interpolation. The right edge pixel coordinates are then determined. This area is the set of pixels in the calibration profile whose signal strength rises from a low-intensity region to a bright-field plateau. Within this area, two adjacent pixels are found. One pixel has a signal strength less than half the height, while the other has a signal strength greater than half the height. Again, based on the coordinates of these two pixels and their corresponding signal strengths, the pixel position corresponding to the half height is calculated using linear interpolation. This position is the right edge pixel coordinates.

[0040] The difference between the coordinates of the right edge pixels and the coordinates of the left edge pixels is calculated to obtain the pixel spacing difference. The target diameter of the object under test is obtained by proportionally converting the pixel pitch difference and pixel scale coefficient.

[0041] Specifically, difference calculation refers to the subtraction operation between the coordinates of the right edge pixel and the coordinates of the left edge pixel; pixel pitch difference refers to the result of the difference calculation, which represents the number of pixels covered by the left and right edges of the measured object on the receiving linear array; pixel scale coefficient refers to the actual physical length corresponding to a single pixel of the receiving linear array, which is pre-calibrated by a standard calibration component; scaling refers to the multiplication operation between the pixel pitch difference and the pixel scale coefficient; the measured object refers to narrow cavity structures such as wind turbine towers or shafts that require internal diameter measurement; the target diameter refers to the value obtained through scaling, which is the actual internal diameter of the measured object.

[0042] Specifically, the control module retrieves the obtained right edge pixel coordinates and left edge pixel coordinates. The right edge pixel coordinates are the pixel position identifiers corresponding to the half-height value of the rising edge on the right side of the calibration diameter profile, and the left edge pixel coordinates are the pixel position identifiers corresponding to the half-height value of the falling edge on the left side of the calibration diameter profile. Then, a difference calculation operation is performed, subtracting the value corresponding to the left edge pixel coordinates from the value corresponding to the right edge pixel coordinates. The result is the pixel pitch difference, which represents the number of pixels covered by the edge of the measured object on the receiving linear array. Next, the control module retrieves the pixel scale coefficient, which has been pre-calibrated using a standard calibration component. This pixel scale coefficient is the actual physical length corresponding to a single pixel in the receiving linear array. Then, a proportional conversion operation is performed, multiplying the pixel pitch difference by the pixel scale coefficient. The calculated value is the actual inner diameter of the measured object, which is the target diameter of the measured object.

[0043] The two-way interaction module is used for two-way interface presentation and interactive calls for the target diameter.

[0044] Specifically, the control module retrieves the target diameter data of the measured object, triggering the bidirectional interface processing module to enter the working state. The bidirectional interface processing module includes a local presentation submodule and an external interaction submodule. Operation panels are located on both the front and back of the display mechanism. After modification, dual-sided display and operation are possible, greatly increasing the viewing angle and operability. The local presentation submodule first converts the target diameter data into an output format compatible with the local display interface of the diameter measuring equipment. The specific value of the target diameter and the corresponding measurement timestamp information are displayed on this local interface. Simultaneously, the local command receiving channel is activated. When the local operator issues a data storage or retest command through the interface operation element, the local presentation submodule converts the command into a control signal and transmits it to the control module, which then executes the corresponding operation. Subsequently, the local presentation submodule synchronously updates the interface display content; the external interaction submodule encapsulates the target diameter data according to the preset communication specifications and sends the encapsulated data to the associated external device through the preset communication link, while maintaining the listening state of the communication link. When it receives a target diameter retrieval command or measurement parameter adjustment command from the external device, the external interaction submodule parses the command and transmits the parsed command information to the control module. The control module executes the operation corresponding to the command. If the operation involves updating the target diameter, the control module feeds back the new target diameter data to the bidirectional interface processing module. This module then synchronously presents the updated target diameter on the local display interface, re-encapsulates it, and pushes it to the external device, thereby completing the bidirectional interface presentation and interactive call of the target diameter.

[0045] To address the above problems, the present invention also provides a bidirectional display and operation method for diameter measurement, see [link to relevant documentation]. Figure 2 Specifically, the method includes: S1. Generate a first leakage band and a second leakage band, and determine the equivalent absorption coefficient based on the first leakage band and the second leakage band; S2. Record the reference reference and reference distance of the reference pixel; S3. Calculate the leakage field estimate based on the wall propagation distance field, equivalent absorption coefficient, reference benchmark and reference distance; S4. Based on the leakage field estimation and the original diameter measurement profile, a corrected diameter measurement profile is generated, and the target diameter of the measured object is determined based on the corrected diameter measurement profile. S5. Provide a two-way interface for displaying and interacting with the target diameter.

[0046] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A laser diameter measuring instrument with bidirectional display and operation, characterized in that, include: The coefficient calibration module is used to generate a first leakage band and a second leakage band, and to determine the equivalent absorption coefficient based on the first leakage band and the second leakage band; The reference recording module is used to record the reference reference and reference distance of the reference pixel; The leakage field calculation module is used to calculate leakage field estimates based on the wall propagation distance field, equivalent absorption coefficient, reference benchmark, and reference distance. The diameter measurement correction module is used to generate a corrected diameter measurement profile based on the leakage field estimation and the original diameter measurement profile, and to determine the target diameter of the object being measured based on the corrected diameter measurement profile. The two-way interactive module is used for two-way interface presentation and interactive call of the target diameter. The operation panel is set on both the front and back of the display mechanism.

2. The laser diameter measuring instrument with bidirectional display and operation according to claim 1, characterized in that, Generating the first leakage band and the second leakage band includes: Turn off the main diameter measuring transmitter and apply auxiliary grazing light to the wall of the cavity to be measured at the first grazing angle and the second grazing angle in sequence. The intensity distribution of the leakage strip corresponding to the first grazing angle and the second grazing angle is collected by the receiving linear array in the edge region of the measurement window to obtain the first leakage strip and the second leakage strip.

3. A laser diameter measuring instrument with bidirectional display and operation according to claim 1, characterized in that, The equivalent absorption coefficient is determined based on the first and second leakage bands, including: Calculate the critical angle based on the refractive index of air and the refractive index of water film; If both the first and second grazing angles are greater than the critical angle, then the wall-guided light condition is satisfied; otherwise, the wall-guided light condition is not satisfied. Under the condition that the light guide along the wall is satisfied, a difference operation is performed on the first leakage strip and the second leakage strip to obtain the leakage signature; Based on the geometric calibration relationship between the measurement window and the wall, the distance of the leaked light from the incident point to each pixel position along the wall is calculated, and the distance field along the wall is generated. Logarithmic linear fitting was performed on the leakage signature and the propagation distance field along the wall to obtain the equivalent absorption coefficient.

4. A laser diameter measuring instrument with bidirectional display and operation according to claim 1, characterized in that, Record the reference reference and reference distance of the reference cell, including: Turn on the main diameter measuring transmitter and acquire the original diameter measuring profile of the object under test in a linear array scanning mode. The original diameter measuring profile is the infrared received signal intensity at the pixel coordinates. In the set of pixels corresponding to the original diametrical profile, the reference pixel closest to the leak is selected according to the geometric calibration relationship between the measurement window and the wall. The received intensity of the reference pixel during the main measurement period is recorded as a reference benchmark, and the reference distance corresponding to the reference pixel is recorded simultaneously.

5. The laser diameter measuring instrument with bidirectional display and operation according to claim 1 is characterized in that, Leakage field estimation is calculated based on the wall propagation distance field, equivalent absorption coefficient, reference baseline, and reference distance, including: The distance difference along the wall is calculated by dividing the distance field propagating along the wall by the reference distance. Multiplying the equivalent absorption coefficient and the difference in distance along the wall yields a linear combination of exponential terms; By performing an exponential operation on the linear combination of exponential terms, the exponential decay factor is obtained. The leakage field estimate is obtained by multiplying the reference baseline and the exponential decay factor.

6. The laser diameter measuring instrument with bidirectional display and operation according to claim 1 is characterized in that, Based on leakage field estimation and the original calibrated calibrated profile, a corrected calibrated profile is generated, including: The leakage field estimate is processed by pixel-by-pixel expansion to obtain the pixel-by-pixel leakage intensity; A pixel-by-pixel cancellation operation is performed on the original diameter measurement profile and the pixel-by-pixel leakage intensity to obtain the corrected diameter measurement profile.

7. A laser diameter measuring instrument with bidirectional display and operation according to claim 1, characterized in that, Determining the target diameter of the object being measured based on the calibrated diametrical profile includes: The maximum value is obtained by iterating through the calibration diameter profile; The half-height value is obtained by proportionally converting the bright-field platform value; Based on the half-height value, linear interpolation search is performed on the left descending edge and the right ascending edge of the calibrated diameter profile to obtain the left edge pixel coordinates and the right edge pixel coordinates. The difference between the coordinates of the right edge pixels and the coordinates of the left edge pixels is calculated to obtain the pixel spacing difference. The target diameter of the object under test is obtained by proportionally converting the pixel pitch difference and pixel scale coefficient.

8. A laser diameter measuring instrument with bidirectional display and operation according to claim 4, characterized in that, The reference pixel closest to the leak point is selected based on the geometric calibration relationship between the measurement window and the wall surface, including: The propagation distance along the wall of each pixel relative to the leak opening is determined based on the pre-established geometric calibration relationship between the measurement window and the wall surface, and the pixel with the smallest propagation distance along the wall is selected as the reference pixel closest to the leak opening.

9. A bidirectional display and operation method for diameter measurement, characterized in that, The method includes: S1. Generate a first leakage band and a second leakage band, and determine the equivalent absorption coefficient based on the first leakage band and the second leakage band; S2. Record the reference reference and reference distance of the reference pixel; S3. Calculate the leakage field estimate based on the wall propagation distance field, equivalent absorption coefficient, reference benchmark and reference distance; S4. Based on the leakage field estimation and the original diameter measurement profile, a corrected diameter measurement profile is generated, and the target diameter of the measured object is determined based on the corrected diameter measurement profile. S5. Provide a two-way interface for displaying and interacting with the target diameter.

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