Pipeline bending angle measuring method and system for servo pipe bending machine

Abstract

The invention discloses a pipeline bending angle measurement method and system for a servo pipe bender, and relates to the technical field of pipeline bending angle measurement and correction, and the system realizes multi-source information synchronous acquisition by acquiring state data, structure size data and image data in a pipeline bending process in real time; performing image processing based on the continuous image frames, and extracting an included angle between the front section and the bent section of the pipeline to obtain a preliminary measurement result; a vibration interference coefficient is calculated and compared with a threshold value, and the measurement stability is judged; calculating a wall surface non-uniformity coefficient according to wall thickness distribution and texture features, and judging and correcting a measurement angle in combination with a threshold value; calculating a plastic deformation coefficient by utilizing material mechanical parameters, judging an inverse deformation trend and further correcting the angle; according to the invention, measurement errors caused by vibration interference, wall surface non-uniformity and plastic deformation are effectively overcome, the accuracy and reliability of pipeline angle measurement of the pipe bending machine are improved, and the method is suitable for high-precision pipeline forming control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipe bending angle measurement and correction, in particular to a pipe bending angle measurement method and system for a servo pipe bender. BACKGROUND

[0002] As a high-precision pipe forming equipment commonly used in the fields of automobile manufacturing, aerospace, shipbuilding and construction engineering, the servo pipe bender has high requirements for the measurement accuracy of the pipe bending angle. In the prior art, the measurement of the bending angle mainly relies on the sensor to collect the position change of the pipe bending spindle or the clamping mechanism, and is supplemented by theoretical calculation of the bending program setting value, or the approximate angle estimation of the pipe profile after deformation through a simple image capture method. However, these methods generally have the following technical problems:

[0003] The measurement result is easily disturbed by mechanical vibration. During the operation of the servo pipe bender, mechanical vibration of the pipe bending spindle and the supporting structure is inevitable, especially during the bending process of pipes with different materials, different wall thicknesses and different bending radii. These vibrations cause significant errors in angle measurement.

[0004] The non-uniformity of the pipe wall surface affects angle recognition. The inconsistency of the texture direction, thickness fluctuation and surface roughness of the inner and outer walls of the pipe often causes image information distortion or angle recognition distortion. Especially when using structured light scanning or industrial camera to shoot the pipe edge profile, the change of wall reflectivity or the non-homogeneity of surface structure will cause feature extraction deviation.

[0005] Plastic deformation causes angle measurement distortion. In the actual pipe bending process, the pipe material undergoes irreversible deformation due to exceeding the yield strength, and its actual geometric shape is inconsistent with the target command value, causing the bending angle to change nonlinearly.

[0006] Lack of multi-factor fusion correction mechanism. The existing system often relies on only a single measurement principle for angle evaluation, and lacks the systematic introduction of multi-source information such as state data, wall surface data and material parameters for angle correction and error control. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a pipe bending angle measurement method and system for a servo pipe bender to solve the problems mentioned in the background art.

[0008] To achieve the above purpose, the present application realizes the following technical scheme: a pipe bending angle measurement method and system for a servo pipe bender, comprising:

[0009] The data acquisition module is used for monitoring the working state of the servo pipe bending machine in real time, collecting state data, including: acceleration value, angular velocity curve and bending radius value in the pipe bending process; collecting structure size data, including: pipe wall thickness value, pipe outer diameter, material elastic modulus and pipe material yield strength; collecting image data, including: height value of each pixel point in the image, pipe inner and outer wall texture direction, density distribution of characteristic texture and continuous image frames in the bending process;

[0010] The bending angle original measurement module is used for obtaining the included angle between the front section and the bending section of the pipe based on an image processing algorithm using the continuous image frames in the bending process, as the original measured bending angle;

[0011] The vibration interference monitoring module is used for extracting the acceleration and angular velocity curve in the pipe bending process in the state data, calculating the vibration interference coefficient ZDx, and comparing and analyzing the vibration interference coefficient ZDx with the first threshold value Q1 to determine whether the original measurement is stable, and if not, a strategy is given;

[0012] The pipe wall surface monitoring module is used for correcting the original measured bending angle which is stable, extracting the maximum wall thickness value, minimum wall thickness value and pipe inner and outer wall texture direction and density distribution of characteristic texture, combining the height value of each pixel point in the image, calculating the wall surface unevenness coefficient BMx, and comparing and analyzing the wall surface unevenness coefficient BMx with the second threshold value Q2 to determine whether the pipe wall surface uniformity is qualified, and if not, a strategy is given to obtain the first corrected angle;

[0013] The plastic deformation monitoring module is used for secondary correction of the first corrected angle θ1 corr , extracting the pipe outer diameter, pipe wall thickness and pipe bending radius, combining the pipe material yield strength, calculating the plastic deformation coefficient SBx, and comparing and analyzing the plastic deformation coefficient SBx with the third threshold value Q3 to determine whether the pipe has a reverse deformation trend, and if so, a strategy is given to obtain the second corrected angle.

[0014] Preferably, the data acquisition module includes a state data acquisition unit, a structure size data acquisition unit and an image data acquisition unit;

[0015] The state data acquisition unit is used for collecting the acceleration value along three spatial axes in the pipe bending process in real time by installing a three-axis accelerometer at the main shaft of the servo pipe bending machine and the bracket connected thereto; collecting the angular velocity curve in real time by installing a gyroscope at the rotation center of the bending main shaft of the servo pipe; collecting the bending radius value by using an encoder in the internal integrated control system of the pipe bending machine;

[0016] The structure size data acquisition unit is used for arranging an ultrasonic thickness gauge and a laser thickness scanner at a pipeline feed inlet to acquire a pipeline wall thickness value; arranging laser calipers on both sides of the pipeline feed inlet to measure a pipeline outer diameter in real time; and acquiring material elastic modulus and pipeline material yield strength through a material manual;

[0017] The image data acquisition unit is used for arranging a structured light three-dimensional scanner or a laser ranging camera in an image channel to acquire a height value of each pixel point in an image; arranging a high-resolution industrial camera between a front end of a servo pipe bending machine spindle and a clamping mechanism to face the inner and outer walls of the pipeline to acquire a density distribution of a texture direction and a characteristic texture of the inner and outer walls of the pipeline; and arranging a top-view industrial camera in a pipeline bending working area to acquire continuous image frames in the bending process.

[0018] Preferably, the bending angle original measurement module is used for extracting continuous image frames in the bending process, identifying center lines of a pipeline feed end and a bending end based on an image processing algorithm, extracting direction vectors of a bending start point and a bending end point in an image coordinate system, and acquiring an included angle between a pipeline front segment and a bending segment as an original measurement bending angle θ raw .

[0019] Preferably, the vibration interference monitoring module includes a first calculation unit and a first analysis unit.

[0020] The first calculation unit is used for extracting acceleration and angular velocity curves in the pipeline bending process, and calculating and acquiring a vibration interference coefficient ZDx after dimensionless processing.

[0021] Preferably, the first analysis unit is used for comparing and analyzing the vibration interference coefficient ZDx with a preset first threshold value Q1 to acquire a first evaluation result, including:

[0022] When the vibration interference coefficient ZDx is less than the first threshold value Q1, it indicates that the original measurement is stable, there is no risk of angle measurement error caused by vibration interference, and the current angle measurement result is used for continuous monitoring.

[0023] When the vibration interference coefficient ZDx is greater than or equal to the first threshold value Q1, it indicates that the original measurement is unstable, there is a risk of angle measurement error caused by vibration interference, a first early warning instruction is triggered, and a first strategy is generated: the fixed pipe fitting is stably reinforced, and recalculation is performed until the vibration interference coefficient ZDx is less than the first threshold value Q1; data in the interference time period is recorded for backtracking adjustment and re-angle measurement.

[0024] Preferably, the pipeline wall surface monitoring module includes a second calculation unit and a second analysis unit.

[0025] The second calculation unit is used for calculating a pipeline wall surface interference coefficient ZDy of the original measurement bending angle θ rawThe maximum wall thickness value, the minimum wall thickness value, and the density distribution of the texture direction and characteristic texture of the inner and outer walls of the pipeline are extracted, and the wall surface non-uniformity coefficient BMx is calculated and obtained after the height value of each pixel in the image is processed dimensionlessly.

[0026] Preferably, the second analysis unit is used to preset a second threshold Q2, and the wall surface non-uniformity coefficient BMx is compared and analyzed with the second threshold Q2 to obtain a second evaluation result, which includes:

[0027] When the wall surface non-uniformity coefficient BMx is less than the second threshold Q2, it indicates that the pipeline wall surface uniformity is qualified, there is no risk of wall surface characteristics interfering with the measurement accuracy, continuous monitoring, and the original measurement bending angle is used;

[0028] When the wall surface non-uniformity coefficient BMx is greater than or equal to the second threshold Q2, it indicates that the pipeline wall surface uniformity is unqualified, there is a risk of wall surface characteristics interfering with the measurement accuracy, a second warning instruction is triggered, and a second strategy is generated: using the wall surface non-uniformity coefficient BMx to reverse correct the measurement result, and obtaining a first corrected angle θ1 after dimensionless processing. corr .

[0029] Preferably, the plastic deformation monitoring module includes a third calculation unit and a third analysis unit.

[0030] The third calculation unit is used to perform secondary correction on the first corrected angle θ1 corr , extract the outer diameter of the pipeline, the wall thickness of the pipeline, and the bending radius of the pipeline, combine the yield strength of the pipeline material, and obtain a plastic deformation coefficient SBx after dimensionless processing.

[0031] Preferably, the third analysis unit is used to preset a third threshold Q3, and the plastic deformation coefficient SBx is compared and analyzed with the third threshold Q3 to obtain a third evaluation result, which includes:

[0032] When the plastic deformation coefficient SBx is less than the third threshold Q3, it indicates that the pipeline has no reverse deformation trend, and continuous monitoring is performed.

[0033] When the plastic deformation coefficient SBx is greater than or equal to the third threshold Q3, it indicates that the pipeline has a reverse deformation trend, and there is a risk of measurement angle distortion, a third warning instruction is triggered, and a third strategy is generated: using the plastic deformation coefficient SBx to reverse correct the first corrected angle θ1 corr , and obtaining a second corrected angle θ2 corr after dimensionless processing.

[0034] Preferably, the pipeline bending angle measurement method for the servo pipe bending machine includes the following steps:

[0035] Step one, by real-time monitoring the working state of the servo pipe bending machine, collecting state data, including: acceleration value, angular velocity curve and bending radius value in the pipe bending process; collecting structure size data, including: pipe wall thickness value, pipe outer diameter, material elastic modulus and pipe material yield strength; collecting image data, including: height value of each pixel point in the image, pipe inner and outer wall texture direction, density distribution of characteristic texture and continuous image frames in the bending process;

[0036] Step two, by using continuous image frames in the bending process, based on image processing algorithm, the included angle formed between the front section and the bending section of the pipe is obtained as the original measured bending angle;

[0037] Step three, by extracting the acceleration and angular velocity curve in the pipe bending process in the state data, the vibration interference coefficient ZDx is calculated and compared with the first threshold Q1 to judge whether the original measurement is stable, if not, the strategy is given;

[0038] Step four, by correcting the original measured bending angle which is stable in measurement, extracting the maximum wall thickness value, minimum wall thickness value and pipe inner and outer wall texture direction and density distribution of characteristic texture, combining the height value of each pixel point in the image, the wall unevenness coefficient BMx is calculated and compared with the second threshold Q2 to judge whether the pipe wall uniformity is qualified, if not, the strategy is given to obtain the first corrected angle;

[0039] Step five, by secondary correction of the first corrected angle θ1 corr combining the pipe outer diameter, pipe wall thickness and pipe bending radius, the plastic deformation coefficient SBx is calculated and compared with the third threshold Q3 to judge whether the pipe has a reverse deformation trend, if so, the strategy is given to obtain the second corrected angle.

[0040] The present application provides a pipe bending angle measurement method and system for a servo pipe bending machine. It has the following beneficial effects:

[0041] The pipe bending angle measurement method and system for the servo pipe bending machine avoids the error problems caused by mechanical backlash, gap vibration and other factors in the traditional contact type angle sensor by using image frame sequence analysis and three-dimensional structured light technology, realizes non-contact, high-resolution bending angle measurement, and improves the overall precision and stability of the system.

[0042] (2) The pipe bending angle measurement method and system for the servo pipe bending machine collects three-axis acceleration and angular velocity data, constructs the vibration interference coefficient ZDx and compares it with the threshold Q1 to judge, the system can accurately identify external vibration interference, and when the interference value exceeds the standard, the dynamic correction mechanism is triggered, so that the measurement process has stronger anti-interference ability.

[0043] (3) The pipe bending angle measurement method and system for the servo pipe bender, a wall unevenness coefficient BMx is constructed to evaluate the interference degree of the pipe surface roughness, thickness variation and texture variation on image feature extraction and angle measurement, and the correction process is automatically started when the wall structure is complex, effectively improving the accuracy and reliability of image processing.

[0044] (4) The pipe bending angle measurement method and system for the servo pipe bender, a plastic deformation coefficient SBx is constructed by using material yield strength, pipe diameter, wall thickness and bending radius and other parameters, which realizes the early identification and compensation of angle misjudgment caused by over-limit deformation, and avoids the influence of plastic springback or residual stress on the final measurement accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 The pipe bending angle measurement system block diagram flow chart for the servo pipe bender of the present application;

[0046] Figure 2 The pipe bending angle measurement method steps schematic diagram for the servo pipe bender of the present application. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0048] Embodiment 1

[0049] Please refer to Figure 1 The present application provides a pipe bending angle measurement method and system for a servo pipe bender, which comprises:

[0050] A data acquisition module is used to monitor the working state of the servo pipe bender in real time, acquire state data, including: acceleration value, angular velocity curve and bending radius value in the pipe bending process; acquire structural size data, including: pipe wall thickness value, pipe outer diameter, material elastic modulus and pipe material yield strength; acquire image data, including: height value of each pixel point in the image, pipe inner and outer wall texture direction, density distribution of characteristic texture and continuous image frames in the bending process;

[0051] A bending angle original measurement module is used to use continuous image frames in the bending process, based on image processing algorithm, to obtain the included angle between the front segment and the bending segment of the pipe, as the original measured bending angle;

[0052] The vibration interference monitoring module is configured to extract an acceleration and angular velocity curve in the pipe bending process in the state data, calculate a vibration interference coefficient ZDx, and compare and analyze the vibration interference coefficient ZDx with a first threshold Q1 to determine whether the original measurement is stable. If the original measurement is not stable, a strategy is given.

[0053] The pipe wall surface monitoring module is configured to correct the original measurement bending angle which is stable, extract a maximum wall thickness value, a minimum wall thickness value, and a density distribution of pipe inner and outer wall texture directions and characteristic textures, combine a height value of each pixel in the image, calculate a wall surface unevenness coefficient BMx, and compare and analyze the wall surface unevenness coefficient BMx with a second threshold Q2 to determine whether the pipe wall surface uniformity is qualified. If the pipe wall surface uniformity is not qualified, a strategy is given to obtain a first corrected angle.

[0054] The plastic deformation monitoring module is configured to correct the first corrected angle θ1 corr extract a pipe outer diameter, a pipe wall thickness, and a pipe bending radius, combine a pipe material yield strength, calculate a plastic deformation coefficient SBx, and compare and analyze the plastic deformation coefficient SBx with a third threshold Q3 to determine whether the pipe has a reverse deformation trend. If the pipe has the reverse deformation trend, a strategy is given to obtain a second corrected angle.

[0055] In the embodiment, by constructing a multi-dimensional data acquisition and hierarchical interference correction mechanism, high-robustness dynamic measurement of the bending angle in the servo pipe bending process is realized. Specifically, the vibration interference, the pipe wall surface unevenness, and the plastic deformation trend are identified and compensated step by step, so that the measured angle not only has high precision, but also has stability and reliability for adapting to complex working conditions, effectively solving the measurement error problem of the traditional measurement method under the vibration fluctuation, surface difference, and material stress feedback.

[0056] Embodiment 2

[0057] This embodiment is an explanation and description in embodiment 1. Specifically, the data acquisition module includes a state data acquisition unit, a structure size data acquisition unit, and an image data acquisition unit.

[0058] The state data acquisition unit is configured to install a three-axis accelerometer at the servo pipe bender main shaft and the bracket connected thereto to acquire the acceleration values along the three spatial axes in real time during the pipe bending process. A gyroscope is installed at the rotation center of the bending main shaft of the servo pipe bender to acquire the angular velocity curve in real time. An encoder is used in the integrated control system in the pipe bender to acquire the bending radius value.

[0059] The structure size data acquisition unit is configured to set an ultrasonic thickness gauge and a laser thickness scanner at the pipe feeding inlet to acquire the pipe wall thickness value. Laser diameter measuring instruments are arranged on both sides of the pipe feeding inlet to measure the pipe outer diameter in real time. The material handbook is used to acquire the material elastic modulus and the pipe material yield strength.

[0060] The image data acquisition unit is configured to configure a structured light three-dimensional scanner or a laser ranging camera in an image channel; acquire reflected brightness information or a laser projection interference pattern image in an image frame; each pixel of the image corresponds to a reflected or phase encoding signal; a grating pattern decoding and triangulation algorithm is used; a fringe grating pattern is projected onto the surface of the pipeline; an industrial camera records the distorted pattern; according to the difference between the projection angle and the shooting angle, the height value of each pixel point in the image is obtained by using the triangulation principle; a high-resolution industrial camera is arranged between the front end of the main shaft of the servo pipe bending machine and the clamping mechanism, and is opposite to the inner and outer walls of the pipeline, so as to acquire the density distribution of the texture direction and characteristic texture of the inner and outer walls of the pipeline; a top-view industrial camera is arranged in the pipeline bending working area to acquire continuous image frames in the bending process.

[0061] In this embodiment, a multi-source data acquisition module covering state monitoring, structural parameter acquisition and image information extraction is constructed by arranging multiple types of high-precision sensors and industrial vision equipment at multiple key positions of the servo pipe bending machine, which can realize comprehensive perception of the changes of multiple physical fields in the pipe bending process, especially through the collaborative work of the three-axis accelerometer, gyroscope, laser ranging camera and structured light three-dimensional scanner, the real-time and fine acquisition capability of the vibration state, pipeline geometric characteristics and surface texture characteristics is significantly improved, which provides a solid data foundation for subsequent high-precision image calculation and interference correction of the bending angle.

[0062] Embodiment 3

[0063] This embodiment is an explanation and description in embodiment 2. Specifically, the bending angle original measurement module is used to extract continuous image frames in the bending process, identify the center lines of the pipe feeding end and the bending end based on an image processing algorithm, extract the direction vectors of the bending start point and the bending end point in the image coordinate system, and obtain the included angle between the front section and the bending section of the pipe as the original measured bending angle θ raw .

[0064] In this embodiment, the center line recognition and direction vector extraction method based on the image processing algorithm is introduced through the bending angle original measurement module, which can automatically obtain the included angle between the pipe feeding end and the bending end by using continuous image frames without relying on traditional physical sensors, realize non-contact high-precision initial measurement of the bending angle, effectively avoid the angle deviation caused by sensor installation error or contact measurement, and improve the flexibility and adaptability of the measurement system.

[0065] Embodiment 4

[0066] This embodiment is an explanation and description in embodiment 3. Specifically, the vibration interference monitoring module includes a first calculation unit and a first analysis unit.

[0067] The first calculation unit is configured to extract the acceleration and angular velocity curves in the pipe bending process, and calculate the vibration disturbance coefficient ZDx after non-dimensional processing, according to the following formula:

[0068]

[0069] In the formula, Arms represents the root mean square value of acceleration, Apeak represents the peak acceleration in the sampling time period, Jsb represents the standard deviation of angular velocity, w1 and w2 represent empirical weight coefficients, 0≤w1≤1, 0≤w2≤1, and w1+w2=1;

[0070] The method for obtaining w1 and w2 is as follows: based on a large number of vibration and angular velocity data of servo pipe bending machines under different working conditions, and in combination with the actual measurement error in the pipe bending process, the relationship between the root mean square value of vibration acceleration, the peak acceleration, the standard deviation of angular velocity and the measurement error is analyzed by statistical analysis, and the regression analysis and experimental calibration methods are used to determine the optimal value range of the empirical weight coefficients w1 and w2. This process fully considers the influence of different materials, pipe diameters and bending speeds on the vibration response, ensures that the weight coefficients adapt to diversified working conditions, and improves the accuracy of the vibration disturbance coefficient ZDx.

[0071]

[0072] In the formula, n represents the total number of acceleration sampling values in the time window, A(t i ) represents the acceleration value at the t i th moment;

[0073]

[0074] In the formula, m represents the total number of angular velocity sampling values in the time window, J(t j ) represents the angular velocity value at the t j th moment, and represents the average value of all angular velocities in the time window.

[0075] In this embodiment, the vibration disturbance monitoring module is set, and the weighted combination of the root mean square value of acceleration, the peak acceleration and the standard deviation of angular velocity is introduced to construct the vibration disturbance coefficient ZDx, so as to realize the quantitative evaluation of the dynamic disturbance caused by the body resonance, load impact or unstable clamping in the servo pipe bending process, effectively improve the judgment ability of the original image measurement reliability, provide a scientific basis for the subsequent interference correction strategy, and improve the stability and robustness of the overall bending angle measurement.

[0076] Embodiment 5

[0077] The embodiment is an explanation in embodiment 4, specifically, the first analysis unit is used to compare and analyze the vibration interference coefficient ZDx with the preset first threshold Q1, and obtain the first evaluation result, including:

[0078] When the vibration interference coefficient ZDx is less than the first threshold Q1, it indicates that the original measurement is stable, and there is no risk of vibration interference causing angle measurement error, and the current angle measurement result is used for continuous monitoring;

[0079] When the vibration interference coefficient ZDx is greater than or equal to the first threshold Q1, it indicates that the original measurement is unstable, and there is a risk of vibration interference causing angle measurement error, a first warning instruction is triggered, and a first strategy is generated: the fixed pipe is stably reinforced, and recalculation is performed until the vibration interference coefficient ZDx is less than the first threshold Q1; record the data of the interference period, and make retroactive adjustment and re-angle measurement.

[0080] The first threshold Q1 is obtained by statistical analysis of a large number of vibration interference coefficients ZDx of servo pipe bending machines, referring to the vibration interference level of normal bending measurement and the critical point of vibration anomaly causing significant increase of measurement error, and combining with industry expert experience and relevant detection standards, the threshold Q1 is reasonably defined, which can effectively distinguish the stable and unstable states in the measurement process, realize accurate early warning of vibration interference risk, and guarantee the stability and accuracy of pipe bending angle measurement.

[0081] In the embodiment, by setting the first analysis unit, the preset first threshold Q1 is used for real-time comparative analysis of the vibration interference coefficient ZDx, which can accurately identify the vibration interference risk in the pipe bending process and judge the stability of angle measurement in time; when the vibration interference exceeds the standard, the system automatically triggers the early warning and generates the targeted stable reinforcement strategy, effectively avoids the measurement error caused by vibration interference, improves the accuracy and reliability of the measurement result, and guarantees the safe and stable operation of the servo pipe bending machine.

[0082] Embodiment 6

[0083] The embodiment is an explanation in embodiment 5, specifically, the pipe wall monitoring module includes a second calculation unit and a second analysis unit;

[0084] The second calculation unit is used to correct the original measurement bending angle θ raw The maximum wall thickness value, the minimum wall thickness value, and the density distribution of the inner and outer wall texture direction and characteristic texture of the pipe are extracted, combined with the height value of each pixel point in the image, and after non-dimensional processing, the wall unevenness coefficient BMx is calculated and obtained, and the formula is as follows:

[0085]

[0086] wherein bh max represents the maximum wall thickness value of the pipeline, bh min represents the minimum wall thickness value of the pipeline, bh avg represents the average wall thickness value of the pipeline, Srms represents the root mean square value of roughness, Sref represents the reference standard roughness of the pipeline surface, λ represents the texture consistency coefficient, a1, a2 and a3 represent empirical weight coefficients, 0≤a1≤1, 0≤a2≤1, 0≤a3≤1 and a1+a2+a3=1;

[0087] The texture consistency coefficient λ is obtained by: acquiring the inner and outer wall surface images of the pipeline by the image acquisition unit, comparing and analyzing the texture direction and feature distribution of the inner and outer walls by using the image processing algorithm, calculating the texture consistency coefficient λ, and taking the value range as 0 to 1. This process can reflect the integrity and uniformity of the wall texture in real time, and is an important part of the wall non-uniformity coefficient BMx, which helps to improve the accuracy of measurement correction.

[0088] The a1, a2 and a3 are obtained by: based on a large number of pipeline bending and wall measurement test data, combining the correlation analysis of key parameters such as pipeline wall thickness change, wall roughness and texture consistency with actual measurement error, determining the optimal values of a1, a2 and a3 by regression analysis and system calibration method, and normalizing them, and the sum is 1; this method fully considers the influence of different materials, surface treatment and bending conditions on the measurement results, ensures that the empirical weight constant adapts to diversified application scenarios, and improves the accuracy of the correction coefficient BMx;

[0089]

[0090] wherein b represents the total number of sampling pixel points, S k represents the height value of the kth pixel point, represents the average height value of all sampling pixel points.

[0091] In this embodiment, by setting the pipeline wall monitoring module, the maximum wall thickness value, the minimum wall thickness value, the average wall thickness value, the surface roughness and the texture consistency and other multi-dimensional image and structure parameters are used to construct the wall non-uniformity coefficient BMx, so as to realize the quantitative evaluation of the uniformity and surface quality of the pipeline wall. This coefficient accurately reflects the actual state of the wall by combining dimensionless processing and empirical weight, effectively identifies the measurement error caused by wall thickness change or surface roughness, promotes real-time correction of the bending angle, and significantly improves the measurement accuracy and the adaptability of the system.

[0092] Example 7

[0093] The embodiment is an explanation of the embodiment 6. Specifically, the second analysis unit is used to preset a second threshold Q2, and the wall unevenness coefficient BMx is compared and analyzed with the second threshold Q2 to obtain a second evaluation result, which includes:

[0094] When the wall unevenness coefficient BMx is less than the second threshold Q2, it indicates that the pipeline wall uniformity is qualified, and there is no risk of wall characteristics interfering with the measurement accuracy. Continuous monitoring is used, and the original measurement bending angle is used.

[0095] When the wall unevenness coefficient BMx is greater than or equal to the second threshold Q2, it indicates that the pipeline wall uniformity is unqualified, and there is a risk of wall characteristics interfering with the measurement accuracy. A second warning instruction is triggered, and a second strategy is generated: using the wall unevenness coefficient BMx to correct the measurement result in reverse. After dimensionless processing, a first corrected angle θ1 is obtained corr , the formula is as follows:

[0096] θ1 corr = θ raw - κ * BMx

[0097] In the formula, θ raw represents the measured bending angle, and κ represents the wall interference correction sensitivity coefficient.

[0098] The acquisition method of κ: through experimental calibration method, the original measurement angle and the measurement angle after wall and texture correction are compared on a plurality of standard pipeline samples. Combined with the actual measurement error and the system response characteristics, the κ value is adjusted to realize the fine reverse correction of the measurement result. The κ value is usually determined through multiple iteration optimization to ensure that the corrected measurement angle reaches the best accuracy when the bending angle is less than a certain threshold range, and to improve the overall measurement stability and reliability of the system.

[0099] The acquisition method of the second threshold Q2: through statistical analysis of a large amount of servo pipe bending machine pipeline wall measurement data, the distribution range of the wall unevenness coefficient BMx under the conditions of normal wall uniformity and wall defect is extracted. Combined with the experience of industry experts and relevant pipeline manufacturing and detection standards, a reasonable wall unevenness qualified critical value Q2 is determined. The threshold value refers to the relevant pipeline surface quality standards and safety specifications of the state or industry to ensure effective identification and early warning of pipeline wall abnormal conditions, so as to ensure the accuracy of measurement and the structural safety of the pipeline.

[0100] In the embodiment, the wall unevenness threshold Q2 is set by the second analysis unit to realize dynamic evaluation of the wall uniformity, and the measurement error risk caused by the wall unevenness can be identified in time. When the wall unevenness coefficient BMx exceeds the threshold, the system automatically triggers a warning and starts a reverse correction strategy based on BMx to scientifically correct the original measured bending angle, effectively reduces the interference of the wall characteristics on the measurement accuracy, and improves the reliability and accuracy of the bending angle measurement.

[0101] Embodiment 8

[0102] The embodiment is an explanation and illustration in embodiment 7. Specifically, the plastic deformation monitoring module includes a third calculation unit and a third analysis unit.

[0103] The third calculation unit is configured to perform secondary correction on the first corrected angle θ1 corr The outer diameter, wall thickness and bending radius of the pipeline are extracted, and the plastic deformation coefficient SBx is calculated after dimensionless processing in combination with the yield strength of the pipeline material. The formula is as follows:

[0104]

[0105] In the formula, σ represents the real-time stress value of the pipeline material, σy represents the yield strength of the pipeline material, which is obtained from the material manual, D represents the outer diameter of the pipeline, and Rb represents the bending radius of the pipeline.

[0106]

[0107] In the formula, E represents the elastic modulus of the material, which is obtained from the material type parameter, bh represents the wall thickness of the pipeline, and Rb represents the bending radius of the pipeline.

[0108] In the embodiment, the plastic deformation coefficient SBx is calculated based on the outer diameter, wall thickness, bending radius, yield strength and elastic modulus of the pipeline material and other parameters by the plastic deformation monitoring module, to realize real-time evaluation of the plastic deformation state of the pipeline during bending. The module can accurately identify whether the pipeline has a reverse deformation trend, and timely adjust and correct the bending angle measurement result, effectively prevent measurement errors caused by plastic deformation, and improve the adaptability and measurement accuracy of the system to complex physical effects.

[0109] Embodiment 9

[0110] The embodiment is an explanation and illustration in embodiment 8. Specifically, the third analysis unit is configured to preset a third threshold Q3, and compare and analyze the plastic deformation coefficient SBx with the third threshold Q3 to obtain a third evaluation result, including:

[0111] When the plastic deformation coefficient SBx is less than the third threshold Q3, it indicates that the pipeline has no reverse deformation trend, and continuous monitoring is performed.

[0112] When the plastic deformation coefficient SBx is greater than or equal to the third threshold Q3, it indicates that the pipe has a reverse deformation trend and there is a risk of angle measurement distortion, a third early warning instruction is triggered, and a third strategy is generated: using the plastic deformation coefficient SBx, the first corrected angle θ1 corr is corrected in the reverse direction, and after non-dimensional processing, the second corrected angle θ2 corr is obtained, and the formula is as follows:

[0113] θ2 corr = θ1 corr - μ * (SBx - Q3);

[0114] In the formula, θ1 corr represents the first corrected angle, μ represents the plastic correction weight coefficient, which is calibrated according to different pipe materials and bending equipment and is used to control the correction degree, and Q3 represents the third threshold.

[0115] The plastic correction weight coefficient μ is obtained in the following manner: based on a large amount of plastic deformation test data and the angle measurement error in the pipe springback process, the optimal value of the correction coefficient μ is determined through system calibration and regression analysis. The coefficient quantifies the influence of the springback trend on the measured angle, and effectively corrects the original measured bending angle. The determination of μ takes into account the material properties, bending radius, wall thickness and actual working conditions, so as to ensure that the correction model can accurately reflect the angle deviation caused by plastic deformation and improve the stability of the overall measurement system.

[0116] The third threshold Q3 is obtained in the following manner: based on the statistical analysis of the plastic deformation coefficient SBx of a large number of servo pipe bending machines under different materials and bending conditions, combined with relevant industry material mechanics standards and safety specifications, the distribution range of SBx under normal plastic deformation and abnormal plastic deformation is divided to determine a reasonable plastic deformation threshold Q3. The threshold can accurately reflect whether the pipe has a reverse deformation trend, and is used as a key parameter for judging whether the bending angle needs to be corrected, so as to ensure the accuracy of the measurement results and the safety of the pipe structure.

[0117] In this embodiment, the plastic deformation threshold Q3 is preset by the third analysis unit to realize real-time monitoring and dynamic evaluation of the plastic deformation coefficient SBx, and effectively identify whether the pipe has a reverse deformation trend. When SBx reaches or exceeds the threshold Q3, the system can timely trigger an early warning and generate a reverse correction strategy based on the plastic deformation coefficient, and use the plastic correction weight coefficient to accurately correct the first corrected angle, thereby significantly reducing the risk of bending angle measurement distortion caused by reverse deformation and improving the accuracy and reliability of the measurement results.

[0118] Embodiment 10

[0119] A pipe bending angle measurement method for a servo pipe bender, please refer to Figure 2 , comprising the following steps:

[0120] Step one, by real-time monitoring the working state of the servo pipe bender, collecting state data, including: acceleration value, angular velocity curve and bending radius value in the pipe bending process; collecting structure size data, including: pipe wall thickness value, pipe outer diameter, material elastic modulus and pipe material yield strength; collecting image data, including: height value of each pixel point in the image, pipe inner and outer wall texture direction, density distribution of characteristic texture and continuous image frames in the bending process;

[0121] Step two, by using the continuous image frames in the bending process, based on image processing algorithm, the included angle formed between the front section and the bending section of the pipe is obtained as the original measurement bending angle;

[0122] Step three, by extracting the acceleration and angular velocity curve in the pipe bending process in the state data, calculating the vibration interference coefficient ZDx, and comparing and analyzing with the first threshold Q1, to judge whether the original measurement is stable, if not, give the strategy;

[0123] Step four, by correcting the original measurement bending angle which is stable in measurement, extracting the maximum wall thickness value, minimum wall thickness value and pipe inner and outer wall texture direction and density distribution of characteristic texture, combining the height value of each pixel point in the image, calculating the wall unevenness coefficient BMx, and comparing and analyzing with the second threshold Q2, to judge whether the pipe wall uniformity is qualified, if not, give the strategy, to obtain the first corrected angle;

[0124] Step five, by twice correcting the first corrected angle θ1 corr , extracting the pipe outer diameter, pipe wall thickness and pipe bending radius, combining the pipe material yield strength, calculating the plastic deformation coefficient SBx, and comparing and analyzing with the third threshold Q3, to judge whether the pipe has inverse deformation trend, if yes, give the strategy, to obtain the second corrected angle.

[0125] In this embodiment, by multi-step, multi-dimensional data collection and analysis, combined with key physical effects such as vibration interference, wall unevenness and plastic deformation, the pipe bending angle measurement result is gradually corrected, the measurement accuracy and stability are effectively improved, the measurement error caused by vibration interference, wall defect and plastic deformation is significantly reduced, and the intelligent monitoring ability and reliability of the servo pipe bender pipe bending process are enhanced.

[0126] The size of the threshold is set for easy comparison, and the size of the threshold depends on the number of sample data and the base number set by the person skilled in the art for each group of sample data; as long as it does not affect the proportional relationship of the parameters and the quantized values.

[0127] The above formulas are obtained by collecting a large amount of data for software simulation and selecting one formula close to the true value, and the coefficients in the formula are set by the person skilled in the art according to the actual situation. The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical range disclosed by the present application, according to the technical solution and the inventive concept of the present application, should be covered within the protection scope of the present application.

Claims

1. A pipe bending angle measuring system for a servo bender, characterized by, The application relates to a servo pipe bending machine original measurement method and device. The data acquisition module is used for monitoring the working state of a servo pipe bending machine in real time, collecting state data, including acceleration values, angular velocity curves and bending radius values in the pipe bending process; collecting structure size data, including pipe wall thickness values, pipe outer diameters, material elastic modulus and pipe material yield strength; and collecting image data, including height values of each pixel point in the image, pipe inner and outer wall texture directions, characteristic texture density distribution and continuous image frames in the bending process; The bending angle original measurement module is used for obtaining the included angle between the front section and the bending section of the pipe based on an image processing algorithm by using the continuous image frames in the bending process, and taking the included angle as the original measurement bending angle. The vibration interference monitoring module is used for extracting the acceleration and angular velocity curves in the pipe bending process from the state data, calculating the vibration interference coefficient ZDx, and comparing and analyzing the vibration interference coefficient ZDx with the first threshold value Q1 to determine whether the original measurement is stable, and if not, a strategy is given. The pipe wall surface monitoring module is used for correcting the original measurement bending angle which is stable in measurement, extracting the maximum and minimum wall thickness values of the pipe, the inner and outer wall texture directions and the characteristic texture density distribution, combining the height values of each pixel point in the image, calculating the wall surface unevenness coefficient BMx, comparing and analyzing the wall surface unevenness coefficient BMx with the second threshold value Q2 to determine whether the pipe wall surface uniformity is qualified, and if not, a strategy is given to obtain the first corrected angle. A plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction angle θ1 corr The plastic deformation monitoring module is configured to monitor the first correction 2. The tube bend angle measuring system for a servo bender as defined in claim 1, wherein The data acquisition module comprises a state data acquisition unit, a structure size data acquisition unit and an image data acquisition unit. The state data acquisition unit is used for collecting the acceleration values along three spatial axes in the pipe bending process by installing a three-axis accelerometer at the main shaft of the servo pipe bending machine and the connected bracket, collecting the angular velocity curve by installing a gyroscope at the rotation center of the bending main shaft of the servo pipe, and collecting the bending radius value by using an encoder in the integrated control system in the pipe bending machine. The structure size data acquisition unit is used for collecting the pipe wall thickness value by arranging an ultrasonic thickness gauge and a laser thickness scanner at the pipe feeding inlet, measuring the pipe outer diameter in real time by arranging laser diameter meters on both sides of the pipe feeding inlet, and collecting the material elastic modulus and the pipe material yield strength by referring to a material manual. The image data acquisition unit is used for arranging a structured light three-dimensional scanner or a laser ranging camera in an image channel to obtain the height values of each pixel point in the image, arranging a high-resolution industrial camera between the front end of the main shaft of the servo pipe bending machine and the clamping mechanism to face the inner and outer walls of the pipe to collect the inner and outer wall texture directions and the characteristic texture density distribution, and arranging a top-view industrial camera at the pipe bending working area to collect continuous image frames in the bending process.

3. The tube bend angle measurement system for a servo bender as defined in claim 2, wherein, The bending angle original measurement module is used to extract continuous image frames in the bending process, identify the center lines of the pipe feeding end and the bending end based on an image processing algorithm, extract the direction vectors of the bending start point and the bending end point in the image coordinate system, and obtain the included angle formed between the front section of the pipe and the bending section as the original measured bending angle θ raw .

4. The tube bend angle measurement system for a servo bender as defined in claim 3, wherein, The vibration interference monitoring module comprises a first calculation unit and a first analysis unit. The first calculation unit is used for extracting the acceleration and angular velocity curves in the pipe bending process, and calculating the vibration interference coefficient ZDx after dimensionless processing.

5. The tube bend angle measurement system for a servo bender as defined in claim 4, wherein, The first analysis unit is used for comparing and analyzing the vibration interference coefficient ZDx with the first threshold value Q1 by presetting the first threshold value Q1 to obtain a first evaluation result. When the vibration interference coefficient ZDx is less than the first threshold Q1, it indicates that the original measurement is stable, and there is no risk of vibration interference causing angle measurement error, and the current angle measurement result is used for continuous monitoring; When the vibration interference coefficient ZDx is greater than or equal to the first threshold Q1, it indicates that the original measurement is unstable, and there is a risk of vibration interference causing angle measurement error, and a first warning instruction is triggered to generate a first strategy: to stabilize and reinforce the fixed pipe, to recalculate until the vibration interference coefficient ZDx is less than the first threshold Q1; record the data of the interference period, and make a retrospective adjustment to re-measure the angle.

6. The tube bend angle measurement system for a servo bender as defined in claim 5, wherein, The pipe wall monitoring module comprises a second calculation unit and a second analysis unit; The second computing unit is configured to correct the original measured bending angle θ raw The maximum wall thickness value, the minimum wall thickness value, the texture direction of the inner and outer walls of the pipeline and the density distribution of the characteristic texture are extracted, the height value of each pixel point in the image is combined, and after non-dimensional processing, the wall unevenness coefficient BMx is calculated and obtained.

7. The tube bend angle measurement system for a servo bender as defined in claim 6, wherein, The second analysis unit is configured to preset a second threshold Q2, and compare and analyze the wall unevenness coefficient BMx with the second threshold Q2 to obtain a second evaluation result, which comprises: When the wall unevenness coefficient BMx is less than the second threshold Q2, it indicates that the pipe wall uniformity is qualified, and there is no risk of wall characteristic interference with the measurement accuracy, and the original measurement bending angle is continuously monitored; When the wall unevenness coefficient BMx is greater than or equal to the second threshold Q2, it indicates that the pipeline wall uniformity is unqualified, there is a risk of wall characteristics interfering with the measurement accuracy, a second warning instruction is triggered, and a second strategy is generated: using the wall unevenness coefficient BMx, the measurement result is corrected in reverse, and after dimensionless processing, the first corrected angle θ1 is obtained corr .

8. The tube bend angle measurement system for a servo bender as defined in claim 7, wherein, The plastic deformation monitoring module comprises a third calculation unit and a third analysis unit; The third calculation unit is configured to perform secondary correction on the first correction angle θ1 corr The third calculation unit is configured to perform secondary correction on the first correction angle θ1 The plastic deformation coefficient SBx is calculated by extracting the pipe outer diameter, the pipe wall thickness, and the pipe bending radius, and combining the yield strength of the pipe material, and then performing dimensionless processing.

9. The tube bend angle measurement system for a servo bender as defined in claim 8, wherein, The third analysis unit is configured to preset a third threshold Q3, and compare and analyze the plastic deformation coefficient SBx with the third threshold Q3 to obtain a third evaluation result, which comprises: When the plastic deformation coefficient SBx is less than the third threshold Q3, it indicates that the pipe has no reverse deformation trend, and continuous monitoring is performed; When the plastic deformation coefficient SBx is greater than or equal to the third threshold Q3, it indicates that the pipe has a reverse deformation trend, and there is a risk of angle distortion, a third early warning instruction is triggered, and a third strategy is generated: using the plastic deformation coefficient SBx, the first corrected angle θ1 corr is corrected in the reverse direction, and after dimensionless processing, the second corrected angle θ2 corr is obtained.

10. A pipe bending angle measuring method for a servo pipe bender according to claims 1 to 9, characterized in that, The method comprises the following steps: Step one, by monitoring the working state of the servo pipe bending machine in real time, collecting state data, including: acceleration value, angular velocity curve and bending radius value in the pipe bending process; collecting structural size data, including: pipe wall thickness value, pipe outer diameter, material elastic modulus and pipe material yield strength; collecting image data, including: height value of each pixel point in the image, pipe inner and outer wall texture direction, density distribution of characteristic texture and continuous image frames in the bending process; Step two, by using the continuous image frames in the bending process, based on the image processing algorithm, the included angle formed between the front section and the bending section of the pipe is obtained as the original measurement bending angle; Step three, by extracting the acceleration and angular velocity curve in the pipe bending process from the state data, the vibration interference coefficient ZDx is calculated and compared with the first threshold Q1 to determine whether the original measurement is stable, and if not, a strategy is given; Step four, by correcting the original measurement bending angle which is stable in measurement, extracting the maximum and minimum wall thickness values of the pipe, the inner and outer wall texture direction and the density distribution of the characteristic texture, and combining the height value of each pixel point in the image, the wall unevenness coefficient BMx is calculated and compared with the second threshold Q2 to determine whether the pipe wall uniformity is qualified, and if not, a strategy is given to obtain a first corrected angle; Step five, by the first correction angle θ1 corr The pipe outer diameter, pipe wall thickness and pipe bending radius are extracted, the plastic deformation coefficient SBx is calculated and obtained by combining the yield strength of the pipe material, and compared with the third threshold Q3 to determine whether the pipe has a reverse deformation trend. If so, a strategy is given to obtain the second correction angle.

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