A method, system and device for detecting pipe wall wear based on a laser scanning detector

Abstract

The present invention relates to a method, system and device for detecting the wear of a pipe wall based on a laser scanning detector. The method comprises the following steps: S1: obtaining a plurality of spacings; S2: calculating the actual inner diameter; S3: determining whether the actual inner diameter exceeds the limit, if so, it is unqualified, otherwise calculating the virtual radius and proceeding to S4; S4: determining whether the virtual radius exceeds the limit, if so, it is unqualified, otherwise calculating the first change rate of the virtual radius; S5: determining whether the first change rate exceeds the limit, if so, it is unqualified, otherwise determining whether the measurement is completed, if so, proceeding to S6, otherwise returning to S1; S6: calculating the second change rate of the actual inner diameter and determining whether the second change rate exceeds the limit, if so, it is unqualified, otherwise proceeding to S7; S7: calculating the third change rate of the virtual radius and determining whether the third change rate exceeds the limit, if so, it is unqualified, otherwise it is qualified. The present invention improves the measurement efficiency on the premise of maintaining the measurement accuracy, discriminates whether the inner wall of the pipe meets the standard from multiple aspects, and improves the accuracy of pipe body detection.

Description

Technical Field

[0001] The present invention relates to the technical field of pipe body detection, and particularly to a method, system and device for detecting wall wear of a pipe wall based on a laser scanning detector. Background Art

[0002] Artillery is the most common weapon in modern warfare. Whether an army has powerful firepower is closely related to the quality of the artillery. The research and development and production of modern artillery have extremely strict standards and requirements for materials and processes. Especially for the barrel, which is a key part of the artillery, due to the extensive use of carbon nickel chromium platinum series alloy steel materials and the extremely complex smelting and processing of gun steel, various technical aspects such as high temperature resistance, high pressure resistance and wear resistance need to be fully considered.

[0003] After the production of the barrel is completed, it is necessary to detect the performance of the barrel to ensure that the shell can be safely and accurately launched. After the barrel is put into use, due to the high temperature, high speed, high pressure and other environmental conditions generated by the shell launch, different degrees of wear will be caused to the barrel. Therefore, it is particularly important to detect the ovality of the inner diameter of the barrel, the wear degree of the inner wall and the actual inner diameter of the barrel body.

[0004] In the extended pipe body detection, manual measurement, scanning measurement or imaging measurement is generally used. The accuracy of manual measurement is low and it is difficult to comprehensively measure the pipe wall. Due to the difficulty in positioning the central axis of the pipe body in the existing scanning measurement methods, the inner diameter of the pipe body cannot be directly measured, and it is difficult to accurately detect the actual condition of the pipe wall. Imaging measurement generally collects images or videos, and then observes the images or videos with the naked eye or performs image recognition. However, since the color of the inner wall of the pipe is almost the same, it is difficult to accurately identify, so it is difficult to detect the unevenness of the pipe wall and the inner diameter of the pipe body. The existing methods for detecting wall wear of a pipe wall still have problems of low accuracy and low efficiency. Summary of the Invention

[0005] Based on this, in view of the problems of low accuracy and low efficiency in the existing detection of wall wear of a pipe wall, it is necessary to provide a method, system and device for detecting wall wear of a pipe wall based on a laser scanning detector.

[0006] The present invention is implemented by the following technical solutions: A method for detecting wall wear of a pipe wall based on a laser scanning detector includes the following steps:

[0007] S1: The detector moves to the initial detection position and then rotates within the to-be-detected tube according to a preset ranging rotation angle. After the detector rotates through each ranging rotation angle, it measures the distance between itself and the inner wall of the tube by emitting laser and receiving the laser echo signal. After the detector rotates one full circle, it translates within the to-be-detected tube according to a preset translation amount. During the detection process, the laser emission direction of the detector is always perpendicular to the central axis of the to-be-detected tube. Among them, the ranging rotation angle is obtained from a conversion table according to the standard caliber of the to-be-detected tube. The conversion table is used to represent the mapping relationship between the standard inner diameter of the to-be-detected tube and the ranging rotation angle.

[0008] S2: Calculate the actual inner diameter of the tube at the current depth position based on the rotation radius of the detector and multiple distances. The depth is the distance of the position where the detector is located relative to the initial detection position along the axial direction of the tube.

[0009] S3: Determine whether the actual inner diameter exceeds a preset inner diameter range. If so, output a non-conforming signal. Otherwise, calculate the virtual radius corresponding to each distance based on the distance and the actual inner diameter, and proceed to S4.

[0010] S4: Determine whether the virtual radius exceeds a preset radius range. If so, output a non-conforming signal. Otherwise, calculate the first change rate of the virtual radius and proceed to S5.

[0011] S5: Determine whether the first change rate exceeds a preset first threshold range. If so, output a non-conforming signal. Otherwise, continue to determine whether the measurement is completed. If the measurement is completed, proceed to S6. Otherwise, return to S1.

[0012] S6: Calculate the second change rate of the actual inner diameter based on multiple actual inner diameters measured by the detector at different depths. Determine whether the second change rate exceeds a preset second threshold range. If so, output a non-conforming signal. Otherwise, proceed to S7.

[0013] S7: Calculate the third change rate of the virtual radius at each angle offset based on multiple virtual radii with the same angle offset. Determine whether the third change rate exceeds a preset third threshold range. If so, output a non-conforming signal. Otherwise, output a conforming signal. Among them, the angle offset is the angle between the laser emission direction of the detector and the initial laser emission direction when measuring the corresponding distance.

[0014] The above detection method calculates the inner diameter and virtual radius of the pipe body at each detection depth in the pipe body by collecting multiple spacing data at different depths of the pipe body respectively, determines whether the inner diameter and virtual radius of the pipe body are within the preset threshold range, and then outputs a qualified signal or an unqualified signal according to the judgment result. The present invention comprehensively considers the accuracy and detection efficiency of pipe wall wear detection, maintains the measurement accuracy of the inner wall of the pipe under the condition of using the least number of measurements, and at the same time judges whether the inner wall of the pipe meets the expected standard by calculating various change rates of the inner diameter of the pipe body, so as to improve the accuracy of detecting the inner wall of the pipe body.

[0015] Preferably, the calculation method of the preset translation amount s is as follows:

[0016]

[0017] where S is the depth of the pipe body to be detected, N is the number of translation times, δ s is the error value of axial detection, and L is the diameter of the laser beam.

[0018] Preferably, the method for obtaining the actual inner diameter is as follows:

[0019] S21: Add the rotation radius and the spacing one by one as the virtual semi-chord.

[0020] S22: Add the two virtual semi-chords measured every 180° as the virtual chord.

[0021] S23: Select the virtual chord with the largest length as the actual inner diameter.

[0022] Preferably, the calculation method of the virtual radius is as follows:

[0023] S31: Map each spacing to a plane coordinate system to form multiple coordinate points. Among them, the distance from each coordinate point to the origin is equal to the sum of the corresponding spacing and the rotation radius, and the angle between the line segment formed by each coordinate point to the origin and the positive direction of the X-axis is equal to the angle offset corresponding to the spacing.

[0024] S32: Circumscribe a minimum circle for the multiple coordinate points as the virtual circle, and the center of the virtual circle is the virtual center.

[0025] S33: Calculate the distance from each coordinate point to the virtual center as the virtual radius corresponding to the corresponding spacing. Preferably, the calculation method of the first change rate of the virtual radius is as follows:

[0026] S41: Calculate the first difference of each virtual radius relative to the previous virtual radius.

[0027] S42: Calculate the first change rate according to the first difference and the actual inner diameter.

[0028] Then the first change rate v i is expressed as:

[0029] v i =δ i / D, (i=2, 3, 4,..., n)

[0030] Among them, δ i is the difference between the ith virtual radius and the (i-1)th virtual radius, D is the actual inner diameter, and n is the number of rotations of the detector.

[0031] In one embodiment, the method for determining whether the measurement is completed is as follows:

[0032] S51: Each time the detector moves horizontally, the number of times the detector moves horizontally is recorded.

[0033] S52: Calculate the total number of translations according to the preset translation amount and the total measurement distance.

[0034] S53: Determine whether the number of translations reaches the total number of translations, and if so, output that the measurement is completed. Otherwise, output that the measurement is not completed.

[0035] Preferably, the calculation method of the change rate 2 is as follows:

[0036] S61: Calculate the difference between each actual inner diameter and the previous actual inner diameter.

[0037] S62: Calculate a second rate of change based on the difference and the standard inner diameter. The standard inner diameter is obtained based on the manufacturing specifications of the pipe body.

[0038] Then the rate of change is v j Expressed as:

[0039] v j =δ j / D0, (j=2, 3, 4,..., m)

[0040] Among them, δ j is the difference between the jth actual inner diameter and the j-1th actual inner diameter, D0 is the standard inner diameter, and m is the total number of translations.

[0041] In one embodiment, the calculation method of the change rate three is as follows:

[0042] S71: Divide the intervals measured at the same angle offset into the same set.

[0043] S72: Calculate the difference between each virtual radius in each set and the virtual radius at the previous position.

[0044] S73: Calculate the change rate three based on the difference and the standard inner diameter.

[0045] Then the rate of change is expressed as:

[0046] v kl = δ kl / D0, (k = 2, 3, 4, ……, n), (l = 2, 3, 4, ……, m)

[0047] where, δ kl is the difference between the virtual radius of the detector rotating k times at the l-th position and the virtual radius of the detector rotating k times at the (l - 1)-th position

[0048] The present invention also provides a pipe wall wear detection system based on a laser scanning detector, which includes: a collection module, an operation module, a decision module, and a detector control module

[0049] The collection module is used to collect the rotation radius of the detector, the laser beam diameter, the standard caliber of the pipe body to be measured, the detection depth of the pipe body to be measured, and a plurality of distances measured by the detector at different positions

[0050] The operation module is used for: (1), calculating the translation amount of the detector according to the input axial error value and the laser beam diameter. (2), calculating the actual inner diameter of the pipe body to be measured according to the rotation radius and the plurality of distances. (3), calculating the virtual radius corresponding to each distance according to the distance and the actual inner diameter. (4), calculating the first change rate of the virtual inner diameter according to the virtual radius and the actual inner diameter. (5), calculating the second change rate of the actual inner diameter according to the calculated plurality of actual inner diameters. (6), calculating the third change rate of the virtual radius at each angular offset according to the angular offset corresponding to each virtual radius

[0051] The decision module is used for: (1), judging whether the calculated plurality of actual inner diameters exceed a preset inner diameter range, and if so, outputting a non-conforming signal. (2) Judging whether the virtual radius exceeds a preset radius range, and if so, outputting a non-conforming signal. (3), judging whether the first change rate exceeds a preset first threshold range, and if so, outputting a non-conforming signal. (4), judging whether the measurement is completed. If the measurement is not completed, outputting a translation instruction. If the measurement is completed, outputting an end instruction. (5), judging whether the second change rate exceeds a preset second threshold range, and if so, outputting a non-conforming signal. (6), judging whether the second change rate exceeds a preset second threshold range, and if so, outputting a non-conforming signal. (7), judging whether a non-conforming signal is output during the entire detection process. If no non-conforming signal is output, outputting a conforming signal

[0052] The detector control module is used for: (1), controlling the detector to rotate one week according to the ranging rotation angle. (2), controlling the detector to translate in the pipe body to be measured according to the translation amount and the translation instruction. (3), controlling the detector to move to the initial position according to the end instruction

[0053] The present invention also provides a pipe wall wear detection device based on a laser scanning detector, which includes a laser scanning detector, a memory, a processor, and a computer program stored on the memory and executable on the processor. Each functional module in the pipe wall wear detection device based on the laser scanning detector is deployed in the manner of the above-mentioned pipe wall wear detection system based on the laser scanning detector. When the processor executes the computer program, the steps of the above-mentioned pipe wall wear detection method based on the laser scanning detector are realized, and then the actual inner diameter and virtual radius of the pipe to be measured at different depth positions are calculated, and it is judged whether the actual inner diameter and virtual inner diameter of the pipe to be measured exceed the preset threshold range, and a qualified signal or an unqualified signal is output according to the judgment result. The laser scanning detector includes a laser ranging sensor and a rotating mechanism. The laser ranging sensor is used to emit a laser detection signal and measure the distance from it to the target object by receiving the echo signal scattered by the target object. The rotating mechanism is fixedly connected to the laser ranging sensor and is used to drive the laser ranging sensor to rotate.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] 1. The present invention collects a plurality of distance data at different depths of the pipe body respectively, and then calculates the inner diameter and virtual radius of the pipe body at each detection depth in the pipe body, and judges whether the inner diameter and virtual radius of the pipe body are within the preset threshold range, and then outputs a qualified signal or an unqualified signal according to the judgment result. The present invention comprehensively considers the accuracy and detection efficiency of pipe wall wear detection, maintains the measurement accuracy of the inner wall of the pipe under the condition of using the least number of measurements, and at the same time judges whether the inner wall of the pipe meets the expected standard by calculating various change rates of the inner diameter of the pipe body, so as to improve the accuracy of pipe wall wear detection.

[0056] 2. The present invention considers the diameter of the detection point formed by the laser emitted with flanks on the inner wall of the pipe, and then calculates the corresponding translation amount according to the beam diameter of the laser emission and the preset maximum error value, and at the same time obtains the corresponding ranging rotation angle in the conversion table according to the standard caliber of the pipe to be measured, so as to complete the comprehensive detection of the inner wall of the pipe to be measured with the least number of measurement points, which not only improves the accuracy of detecting the wear of the pipe wall to be measured, but also improves the detection efficiency. Description of the Drawings

[0057] Figure 1 is a flow chart of the pipe wall wear detection method based on the laser scanning detector in Embodiment 1 of the present invention;

[0058] Figure 2 is Figure 1 a schematic diagram of the calculation method of the virtual radius in;

[0059] Figure 3 is according to Figure 1Schematic diagram of the structure of the pipe wall wear detection system based on laser scanning detector designed by the pipe wall wear detection method based on laser scanning detector. DETAILED DESCRIPTION

[0060] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0061] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component. When a component is considered to be "fixed to" another component, it may be directly fixed to the other component or there may be a central component.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0063] Example 1

[0064] See also Figure 1 , which is a flow chart of the pipe wall wear detection method based on the laser scanning detector provided in this embodiment. The pipe wall wear detection method based on the laser scanning detector includes the following steps:

[0065] S1: The detector moves to the initial inspection position and then rotates within the tube according to a preset ranging angle. After each ranging angle rotation, the detector measures the distance between itself and the inner wall of the tube by emitting a laser and receiving the laser echo signal. After one rotation, the detector translates within the tube according to a preset translation amount. During the inspection process, the laser emission direction of the detector remains perpendicular to the central axis of the tube. The ranging angle is obtained from a conversion table based on the standard inner diameter of the tube to be tested. The conversion table represents the mapping between the standard inner diameter of the tube to be tested and the ranging angle.

[0066] For the detection of the inner wall of the pipe, theoretically, the entire inner surface of the pipe diameter should be covered. However, in actual detection, due to the allowable maximum error value in the detection standard of the pipe diameter, the partial point measurement of the pipe wall can be carried out by means of interval measurement to replace the full-coverage measurement. Thus, under the condition of ensuring the detection accuracy, the detection steps can be simplified and the detection efficiency of the pipe wall can be improved.

[0067] According to the diameter and depth of the pipe to be measured, by introducing the maximum error value, the number of points that actually need to be detected during the actual detection process of the detector can be calculated. In order to simplify the detection steps, in this embodiment, the step-by-step rotation measurement method is adopted to accurately detect the inner wall of the pipe. According to the diameter of the laser beam of the detector and the depth error, the number of translation times required for the detector to measure the entire inner wall of the pipe is calculated, and then the displacement amount of each translation of the detector is calculated.

[0068] The calculation method of the preset translation amount s is as follows:

[0069]

[0070] where S is the depth of the pipe to be detected, N is the number of translation times, δ s is the error value of axial detection, and L is the diameter of the laser beam.

[0071] The detector translates successively according to the displacement amount, and after each translation, the entire circular cross-section of the inner wall of the pipe is measured. According to the beam diameter and the distance error of the measurement point, the number of measurement points required for the detector to measure the entire circular cross-section of the pipe is calculated, and then the ranging rotation angle of each rotation of the detector is calculated.

[0072] In the conversion table, the relationship between the standard diameter of the pipe and the ranging rotation angle is as follows:

[0073] Assume that the standard diameter of the pipe is D s , the beam diameter is L, and the distance between the rotation axis of the scanner and the central axis of the pipe is not greater than d s , then the maximum ranging rotation angle covering the entire inner diameter is the minimum central angle corresponding to the beam diameter, and the maximum ranging rotation angle θ h is expressed as:

[0074] θ h = arccos[2(D s +d s ) 2 -L 2 / 2(D s +d s ).

[0075] In actual detection, in order to facilitate the measurement of the pipe inner diameter, the number of measurement points is set to an even number, and the actual number of measurement points is:

[0076] 2π / θ h +2 > N h ≥ 2π / θ h

[0077] Actual ranging rotation angle θ f is:

[0078] θ f = 2π / N h .

[0079] S2: Calculate the actual inner diameter of the pipe body at the current depth position according to the rotation radius of the detector and multiple spacings. The depth is the distance of the position where the detector is located relative to the initial detection position along the axial direction of the pipe body.

[0080] The method for obtaining the actual inner diameter is as follows:

[0081] S21: Obtain the rotation radius of the detector's self-rotation, and stack the rotation radius and the spacing data one by one as the virtual semi-chord.

[0082] During the self-rotation of the detector, since the laser emission point of the laser ranging sensor and the rotation center of the detector are not in the same position, therefore, it is necessary to first obtain the spacing between the laser emission point and the rotation center as the rotation radius. The rotation radius can generally be directly obtained from the specification information of the detector, and of course, it can also be obtained through actual measurement. Adding the measured multiple spacing data to the rotation radius is regarded as the actual distance from the rotation center to the inner wall of the pipe body.

[0083] Assume the rotation radius is r, and the n spacings measured at any position are recorded as the data set recorded as A i (i = 1, 2, 3,..., n). Then the corresponding virtual semi-chord can be recorded as C i (i = 1, 2, 3,..., n), and

[0084] C i = A i + r.

[0085] S22: Stack the two virtual semi-chords measured every 180° as the virtual chord.

[0086] According to the definition of the chord, the line segment connecting any two points on the circle is the chord. Since one end of each virtual semi-chord falls on the rotation center, then the two virtual semi-chords every 180° are just on the same straight line, and the line segment connecting the two virtual semi-chords can be regarded as the virtual chord.

[0087] Then the virtual chord B i is expressed as:

[0088] B i = C i + C i+180 .

[0089] S23: Select the virtual chord with the maximum length as the actual inner diameter.

[0090] According to the definition of a circle, the diameter is the longest chord passing through any point inside the circle. Therefore, among the multiple virtual chords obtained, the virtual chord with the maximum length can be regarded as the actual inner diameter D at the corresponding position on the inner wall of the tube body.

[0091] S3: Determine whether the actual inner diameter exceeds a preset inner diameter range. If it does, output a non-conforming signal. Otherwise, calculate the virtual radius corresponding to each spacing based on the spacing and the actual inner diameter, and proceed to S4.

[0092] Due to existing process limitations and considering the actual application of the tube body, there may be a certain error between the actual inner diameter of the inner wall of the tube body and the standard inner diameter. Judge the actual inner diameter of the tube body according to the rated standard inner diameter range of the tube body. The tube body whose actual inner diameter exceeds the standard inner diameter range is regarded as a non-conforming tube body. In this embodiment, the preset inner diameter range is set according to the standard caliber of the tube body to be measured, denoted as [-1.01D s , 1.01D s . Of course, in other embodiments, the preset inner diameter range can be larger or smaller.

[0093] Please refer to Figure 2 , which is a schematic diagram of the calculation method of the virtual radius in Figure 1 . The calculation method of the virtual radius is as follows:

[0094] S31: Map each spacing to a plane coordinate system to form multiple coordinate points. Among them, the distance from each coordinate point to the origin is equal to the sum of the corresponding spacing and the rotation radius, and the angle between the line segment formed by each coordinate point to the origin and the positive direction of the X-axis is equal to the angle offset corresponding to the spacing.

[0095] For any spacing A i , the corresponding coordinate point P can be denoted as (C i cos(cθ f ), C i sin(cθ f )), where c is the number of rotations of the detector at the corresponding position.

[0096] S32: Circumscribe a minimum circle for the multiple coordinate points as the virtual circle, and the center of the virtual circle is the virtual center.

[0097] The virtual circle can be constructed according to the actual inner diameter, that is, taking the center of the actual inner diameter as the center of the virtual circle and half of the actual inner diameter as the radius of the virtual circle to construct the virtual circle. Assume that the two endpoints of the actual diameter are K(A0cos(c0θ f ), A0sin(c0θ f )) and K’(Aπ cos(c0θ f +π), A π sin(c0θ f +π)), then the virtual center O1 can be denoted as:

[0098] ([A0cos(c0θ f ) + A π cos(c0θ f +π)] / 2, [A0sin(c0θ f ) + A π sin(c0θ f +π)] / 2).

[0099] S33: Calculate the distance from each coordinate point to the virtual center as the virtual radius corresponding to the respective spacing.

[0100] Then for any spacing A i the corresponding virtual radius r i can be denoted as:

[0101]

[0102] where x i = C i cos(cθ f ), y i = C i sin(cθ f ), x0 = [A0cos(c0θ f ) + A π cos(c0θ f +π)] / 2, y0 = [A0sin(c0θ f ) + A π sin(c0θ f +π)] / 2.

[0103] S4: Determine whether the virtual radius exceeds a preset radius range. If so, output a non - qualified signal. Otherwise, calculate the change rate one of the virtual radius and proceed to S5.

[0104] At any depth position of the pipe body, in addition to the actual inner diameter possibly exceeding the preset range, there may also be a certain degree of ovality or protrusions inside the pipe. Therefore, it is also necessary to judge the smoothness of the pipe inner diameter. If there are protrusions or depressions beyond the specifications on the inner wall of the pipe, an obvious difference will be formed between two consecutive detection points.

[0105] In this embodiment, the preset radius range is set to [-0.505D s , 0.505D s, of course, in other embodiments, the preset radius range can be larger or smaller.

[0106] The calculation method of the first change rate of the virtual radius is as follows:

[0107] S41: Calculate the first difference of each virtual radius relative to the previous virtual radius.

[0108] S42: Calculate the first change rate according to the first difference and the actual inner diameter.

[0109] Then the first change rate v i is expressed as:

[0110] v i = δ i / D, (i = 2, 3, 4,..., n)

[0111] where, δ i is the difference between the i-th virtual radius and the (i - 1)-th virtual radius, D is the actual inner diameter, and n is the number of rotations of the detector in one week of rotation.

[0112] Of course, in other embodiments, the first change rate of the virtual radius can also be the ratio of the first difference to the standard caliber δ i / D s , or the ratio of the first difference to the current virtual radius δ i / r i , and can also be other ratios related to the first difference, as long as it can characterize the change trend of the virtual inner diameter.

[0113] S5: Determine whether the first change rate exceeds a preset first threshold range. If it does, output a non-conforming signal. Otherwise, continue to determine whether the measurement is completed. If the measurement is completed, perform S6. Otherwise, return to S1.

[0114] If the first change rate exceeds the preset first threshold range, it means that there are obvious protrusions or depressions on the inner wall of the pipe. After the gun barrel is put into use, due to the irreversible wear caused by the shell firing on the pipe wall, it is necessary to conduct a comprehensive inspection of the inner wall of the gun barrel after each use to avoid accidents and ensure the safe and accurate firing of the shell.

[0115] In this embodiment, the first threshold range is set to [-0.005, 0.005]. Of course, in other embodiments, the first threshold range can be larger or smaller.

[0116] Among them, the method for determining whether the measurement is completed is as follows:

[0117] S51: Each time the detector translates, record the number of translations.

[0118] S52: Calculate the total number of translations according to the preset translation amount and the total measurement distance.

[0119] S53: Determine whether the number of translations has reached the total number of translations. If so, output that the measurement is completed. Otherwise, output that the measurement is not completed.

[0120] For the detector to accurately detect the inner wall of the pipe, it needs to be translated from one end of the pipe to the other end. During this process, the detector makes multiple equidistant translations. After the detector measures all the spacings, it is also necessary to further process the data. Therefore, it is possible to first confirm that the detection process is completed to enable the detector to automatically reset and improve the detection efficiency.

[0121] S6: Calculate the change rate two of the actual inner diameter based on multiple actual inner diameters measured by the detector at different depths. Determine whether the change rate two exceeds a preset threshold range two. If so, output a non-conforming signal. Otherwise, proceed to S7.

[0122] In pipe measurement, in addition to determining whether the circumferential inner diameter at each position exceeds the standard inner diameter range, it is also necessary to determine whether the change in the axial inner diameter of the inner wall of the pipe exceeds the standard inner diameter range. To simplify the judgment process, first judge the change in multiple actual inner diameters, and then judge the actual inner diameters with different angular offsets.

[0123] Among them, the calculation method of the change rate two is as follows:

[0124] S61: Calculate the difference between each actual inner diameter and the previous inner diameter.

[0125] S62: Calculate the change rate two based on the difference and the standard inner diameter.

[0126] Then the change rate two v j is expressed as:

[0127] v j = δ j / D s , (j = 2, 3, 4,..., m)

[0128] Among them, δ j is the difference between the jth actual inner diameter and the (j - 1)th actual inner diameter, D s is the standard inner diameter, and m is the total number of translations.

[0129] In this embodiment, the threshold range two is set to [-0.01, 0.01]. Of course, in other embodiments, the threshold range two can be larger or smaller.

[0130] S7: Calculate the change rate three of the virtual radius at each angular offset based on the virtual radius at the same angular offset for each position. Determine whether the change rate three exceeds a preset threshold range three. If it does, output a non-conforming signal; otherwise, output a conforming signal. Here, the angular offset is the angle between the laser emission direction of the detector and the initial laser emission direction.

[0131] The calculation method of the change rate three is as follows:

[0132] S71: Divide the spacings measured at the same angular offset into the same set respectively.

[0133] S72: Calculate the difference between each virtual radius in each set and the virtual radius at the previous position.

[0134] S73: Calculate the change rate three based on the difference and the standard inner diameter.

[0135] Then the change rate three v kl is expressed as:

[0136] v kl = δ kl / D0, (k = 2, 3, 4,..., n), (l = 2, 3, 4,..., m)

[0137] where, δ kl is the difference between the virtual radius of the detector rotating k times at the l-th position and the virtual radius of the detector rotating k times at the (l - 1)-th position.

[0138] In this embodiment, the threshold range three is the same as the threshold range one, both being [-0.005, 0.005]. Of course, in other embodiments, the threshold range three can be larger or smaller.

[0139] In this embodiment, by collecting multiple spacing data at different depths of the pipe body respectively, and then calculating the inner diameter and virtual radius of the pipe body at each detection depth, it is determined whether the inner diameter and virtual radius of the pipe body are within the preset threshold range, and then a conforming signal or a non-conforming signal is output according to the judgment result. The present invention comprehensively considers the accuracy and detection efficiency of the pipe wall wear detection. Under the condition of using the least number of measurements, it maintains the measurement accuracy of the inner wall of the pipe. At the same time, by calculating various change rates of the inner diameter of the pipe body, it is determined whether the inner wall of the pipe meets the expected standard, thereby improving the accuracy of the pipe wall wear detection.

[0140] Embodiment 2

[0141] Please combine Figure 3 which is based on Figure 1This embodiment also provides a laser scanning instrument-based pipe wall wear detection system. This system includes an acquisition module, a calculation module, a decision module, and a detector control module.

[0142] The acquisition module is used to collect the detector's rotation radius, laser beam diameter, the standard caliber of the pipe being tested, the detection depth of the pipe being tested, and multiple distances measured by the detector at different locations. The rotation radius, laser beam diameter, and standard caliber can all be directly obtained from the specifications of the detector or the pipe being tested. The detection depth can be set based on the inner lumen depth of the pipe being tested and the actual measurement error, such as 80% of the inner lumen depth. The distances measured by the detector at different locations are calculated by emitting a detection laser and receiving the laser echo signal, thereby calculating the distance between the detector and the inner wall of the pipe.

[0143] The calculation module is used to: (1) calculate the translation of the detector based on the input axial error value and the laser beam diameter. The translation can be expressed as:

[0144]

[0145] Among them, S is the depth of the pipe to be detected, N is the number of translations, δ s is the error value of axial detection, and L is the laser beam diameter.

[0146] (2) Calculate the actual inner diameter of the tube to be measured based on the rotation radius and multiple spacings. The calculation method of the actual inner diameter is as follows:

[0147] The rotation radius and spacing data are superimposed one by one as a virtual half chord. Assuming that the rotation radius is r, the n spacings measured at any position are recorded as a data set and recorded as A. i (i=1,2,3,……,n). Then the corresponding virtual half chord can be recorded as C i (i=1,2,3,...,n), and

[0148] C i =A i +r.

[0149] The two virtual half-chords measured at 180° intervals are superimposed to form a virtual chord. The definition of a chord indicates that a line segment connecting any two points on a circle is a chord. Since one end of each virtual half-chord falls on the center of rotation, two virtual half-chords at 180° intervals coincide with each other, and the line segment formed by these two virtual half-chords can be considered a virtual chord.

[0150] Then the virtual chord B i is expressed as:

[0151] B i = C i + C i+180 .

[0152] Select the virtual chord with the maximum length as the actual inner diameter. According to the definition of a circle, the diameter is the longest chord passing through any point inside the circle. Therefore, among the multiple virtual chords obtained, the virtual chord with the maximum length can be regarded as the actual inner diameter D at the corresponding position of the inner wall of the pipe.

[0153] (3) Calculate the virtual radius corresponding to each pitch according to the pitch and the actual inner diameter. The calculation method of the virtual radius is as follows:

[0154] Map each pitch to a plane coordinate system to form multiple coordinate points. Among them, the distance from each coordinate point to the origin is equal to the sum of the corresponding pitch and the rotation radius, and the angle between the line segment formed by each coordinate point to the origin and the positive direction of the X-axis is equal to the angle offset corresponding to the pitch.

[0155] For any pitch A i , the corresponding coordinate point P can be recorded as (C i cos(cθ f ), C i sin(cθ f )), where c is the number of rotations of the detector at the corresponding position.

[0156] Circumscribe a minimum circle for the multiple coordinate points as the virtual circle, and the center of the virtual circle is the virtual center.

[0157] The virtual circle can be constructed according to the actual inner diameter, that is, taking the center of the actual inner diameter as the center of the virtual circle and half of the actual inner diameter as the radius of the virtual circle to construct the virtual circle. Assume that the two endpoints of the actual diameter are K(A0cos(c0θ f ), A0sin(c0θ f )) and K'(A π cos(c0θ f + π), A π sin(c0θ f + π)), then the virtual center O1 can be recorded as:

[0158] ([A0cos(c0θ f ) + A π cos(c0θ f + π)] / 2, [A0sin(c0θ f ) + A π sin(c0θ f + π)] / 2).

[0159] Calculate the distance from each coordinate point to the virtual center as the virtual radius corresponding to the respective spacing.

[0160] Then for any spacing A i the corresponding virtual radius r i can be denoted as:

[0161]

[0162] where x i = C i cos(cθ f ), y i = C i sin(cθ f ), x0 = [A0cos(c0θ f ) + A π cos(c0θ f + π)] / 2, y0 = [A0sin(c0θ f ) + A π sin(c0θ f + π)] / 2.

[0163] (4) Calculate the first change rate of the virtual inner diameter based on the virtual radius and the actual inner diameter. The first change rate v i is expressed as:

[0164] v i = δ i / D, (i = 2, 3, 4,..., n)

[0165] where δ i is the difference between the i-th virtual radius and the (i - 1)-th virtual radius, D is the actual inner diameter, and n is the number of rotations of the detector in one full circle.

[0166] (5) Calculate the second change rate of the actual inner diameter based on the calculated multiple actual inner diameters. The second change rate v j is expressed as:

[0167] v j = δ j / D s , (j = 2, 3, 4,..., m)

[0168] where δ j is the difference between the j-th actual inner diameter and the (j - 1)-th actual inner diameter, D s is the standard inner diameter, and m is the total number of translations.

[0169] (6) Calculate the third change rate of the virtual radius at each angular offset based on the angular offset corresponding to each virtual radius. The third change rate v kl is expressed as:

[0170] v kl =δ kl / D0, (k = 2, 3, 4, ……, n), (l = 2, 3, 4, ……, m)

[0171] Where, δ kl is the difference between the virtual radius of the detector rotating k times at the l-th position and the virtual radius of the detector rotating k times at the (l - 1)-th position.

[0172] The decision module is used for: (1) Judging whether multiple calculated actual inner diameters exceed a preset inner diameter range. If so, an unqualified signal is output. In this embodiment, the preset inner diameter range is set according to the standard caliber of the pipe to be measured, denoted as [-1.01D s , 1.01D s . Of course, in other embodiments, the preset inner diameter range can be larger or smaller.

[0173] (2) Judging whether the virtual radius exceeds a preset radius range. If so, an unqualified signal is output. In this embodiment, the preset radius range is set to [-0.505D s , 0.505D s . Of course, in other embodiments, the preset radius range can be larger or smaller.

[0174] (3) Judging whether the first change rate exceeds a preset first threshold range. If so, an unqualified signal is output. In this embodiment, the first threshold range is set to [-0.005, 0.005]. Of course, in other embodiments, the first threshold range can be larger or smaller.

[0175] (4) Judging whether the measurement is completed. If the measurement is not completed, a translation instruction is output. If the measurement is completed, an end instruction is output. The method for judging whether the measurement is completed is as follows:

[0176] Each time the detector is translated, the translation count is recorded. The total translation count is calculated according to the preset translation amount and the total measurement distance. Judge whether the translation count reaches the total translation count. If so, output that the measurement is completed. Otherwise, output that the measurement is not completed.

[0177] (5) Judging whether the second change rate exceeds a preset second threshold range. If so, an unqualified signal is output. In this embodiment, the second threshold range is set to [-0.01, 0.01]. Of course, in other embodiments, the second threshold range can be larger or smaller.

[0178] (6) Determine whether the rate of change 3 exceeds a preset threshold range 3. If so, output a failure signal. In this embodiment, the threshold range 3 is the same as the threshold range 1, both being [-0.005, 0.005]. Of course, in other embodiments, the threshold range 1 can be larger or smaller.

[0179] (7) Determine whether a failure signal is output during the entire test process. If no failure signal is output, a qualified signal is output. During the test process, if any of the parameters of the pipe body to be tested are unqualified, the pipe body will be considered unqualified as a whole. After the test is completed, if all parameters do not exceed the preset threshold range, the pipe body will be considered qualified.

[0180] The detector control module is used to: (1) control the detector to rotate one circle according to the ranging angle. The ranging angle is directly obtained from a conversion table based on the standard diameter of the pipe to be measured. When the detector is at any depth position, each time it rotates one ranging angle, it measures the distance between itself and the inner wall of the pipe, thereby achieving a balance between measurement accuracy and measurement efficiency.

[0181] (2) The detector is controlled to translate within the pipe to be measured based on the translation amount and translation instructions. After the detector rotates one circle at any depth position, if the entire measurement process has not been completed, a translation instruction is issued to control the detector to continue to translate into the pipe. The detector translates a preset translation amount each time.

[0182] (3) Control the detector to move to the initial position according to the end instruction. When the detector completes the entire measurement process, it automatically resets according to the output end instruction and reminds the operator to remove the detector from the pipe body. During the removal process, the detector continues to judge the threshold value of the pipe body diameter until the final test result is output.

[0183] Example 3

[0184] In order to use the above-mentioned pipe wall wear detection method based on a laser scanning detector to perform pipe wall wear detection on an existing laser scanning detector, this embodiment further provides a pipe wall wear detection device based on a laser scanning detector.

[0185] It includes a laser scanning detector, a memory, a processor, and a computer program stored on the memory and executable on the processor. Each functional module in the pipe wall wear detection device based on the laser scanning detector is deployed in the manner of the above-mentioned pipe wall wear detection system based on the laser scanning detector. When the processor executes the computer program, it implements the steps of the above-mentioned pipe wall wear detection method based on the laser scanning detector, and then calculates the actual inner diameter and virtual radius of the pipe to be measured at different depth positions, determines whether the actual inner diameter and virtual inner diameter of the pipe to be measured exceed the preset threshold range, and outputs a qualified signal or an unqualified signal according to the judgment result. The laser scanning detector includes a laser ranging sensor and a rotating mechanism. The laser ranging sensor is used to emit a laser detection signal and measure its distance from the target object by receiving the echo signal scattered by the target object. The rotating mechanism is fixedly connected to the laser ranging sensor and is used to drive the laser ranging sensor to rotate.

[0186] The computer device can be a smart phone, a tablet computer, a notebook computer, a desktop computer, a rack server, a blade server, a tower server or a cabinet server (including an independent server or a server cluster composed of multiple servers) that can execute programs. The computer device of this embodiment at least includes, but is not limited to, a memory and a processor that can communicate with each other through a system bus.

[0187] In this embodiment, the memory (i.e., the readable storage medium) includes flash memory, a hard disk, a multimedia card, a card-type memory (such as an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, etc. In some embodiments, the memory can be an internal storage unit of the computer device, such as the hard disk or memory of the computer device. In other embodiments, the memory can also be an external storage device of the computer device, such as a plug-in hard disk equipped on the computer device, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Of course, the memory can also include both the internal storage unit and the external storage device of the computer device. In this embodiment, the memory is usually used to store the operating system and various application software installed on the computer device. In addition, the memory can also be used to temporarily store various data that have been output or will be output.

[0188] The processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips in some embodiments. The processor is generally used to control the overall operation of the computer device. In this embodiment, the processor is used to run the program code stored in the memory or process data, thereby implementing the steps of the above-mentioned method for detecting the wall wear of the pipe based on the laser scanning detector, and then calculating the actual inner diameter and virtual radius of the pipe to be measured at different depth positions, determining whether the actual inner diameter and virtual inner diameter of the pipe to be measured exceed the preset threshold range, and outputting a qualified signal or an unqualified signal according to the judgment result.

[0189] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0190] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A pipe wall wear detection method based on a laser scanning detector, characterized in that: It includes the following steps: S1: The detector moves to the initial detection position and then rotates within the tube to be measured according to a preset ranging angle. After each ranging angle rotation, the detector measures the distance between itself and the inner wall of the tube by emitting laser and receiving laser echo signals. After one rotation, the detector translates within the tube to be measured according to a preset translation amount. During the measurement process, the laser emission direction of the detector is always perpendicular to the central axis of the tube to be measured. The ranging angle is obtained from a conversion table based on the standard inner diameter of the tube to be measured. The conversion table is used to represent the mapping relationship between the standard inner diameter of the tube to be measured and the ranging angle. The preset translation amount s is calculated as follows: Among them, S is the depth of the pipe to be detected, N is the number of translations, is the error value of axial detection, L is the laser beam diameter; S2: Calculate the actual inner diameter of the pipe at the current depth position based on the rotation radius of the detector and the multiple spacings; the depth is the distance along the axial direction of the pipe from the position of the detector relative to the initial detection position; the actual inner diameter is obtained as follows: S21: superimposing the rotation radius and the distance one by one to obtain a virtual half chord; S22: superimpose two virtual half chords measured every 180° as a virtual chord; S23: Select the virtual chord with the largest length as the actual inner diameter; S3: Determine whether the actual inner diameter exceeds a preset inner diameter range. If yes, output a failure signal. Otherwise, calculate the virtual radius corresponding to each spacing according to the spacing and the actual inner diameter, and proceed to S4. The virtual radius is calculated as follows: S31: Mapping each of the spacings into a plane coordinate system to form multiple coordinate points; wherein the distance between each coordinate point and the origin is equal to the sum of the corresponding spacing and the rotation radius, and the angle between the line segment formed by each coordinate point to the origin and the positive direction of the X-axis is equal to the angular offset corresponding to the spacing; S32: circumscribing a minimum circle around the plurality of coordinate points as a virtual circle, wherein the center of the virtual circle is the virtual center; S33: Calculate the distance from each coordinate point to the virtual circle center as the virtual radius corresponding to the corresponding spacing; S4: Determine whether the virtual radius exceeds a preset radius range. If yes, output a failure signal. Otherwise, calculate the change rate of the virtual radius and proceed to S5. The calculation method of the change rate of the virtual radius is as follows: S41: Calculate the difference of each virtual radius relative to the previous virtual radius; S42: Calculating the change rate 1 according to the difference 1 and the actual inner diameter; Then the rate of change is Expressed as: in, For the i The virtual radius is relative to the The difference in virtual radii, D is the actual inner diameter, and n is the number of rotations of the detector during one revolution; S5: Determine whether the change rate exceeds a preset threshold range. If so, output a failure signal. Otherwise, continue to determine whether the measurement is completed. If so, proceed to S6. Otherwise, return to S1. S6: Calculating a second rate of change of the actual inner diameter based on multiple actual inner diameters measured by the detector at different depths; determining whether the second rate of change exceeds a preset threshold range, and outputting a failure signal; otherwise, proceeding to S7; S7: Calculate the rate of change of the virtual radius at each angle offset based on multiple virtual radii with the same angle offset; determine whether the rate of change exceeds a preset threshold range, and if so, output an unqualified signal; otherwise, output a qualified signal; wherein the angle offset is the angle between the laser emission direction of the detector and the initial laser emission direction when measuring the corresponding spacing.

2. The pipe wall wear detection method based on a laser scanning detector according to claim 1 is characterized in that: In S5, the method for determining whether the measurement is completed is as follows: S51: Each time the detector moves horizontally, the number of times the detector moves horizontally is recorded; S52: Calculating the total number of translations according to the preset translation amount and the total measurement distance; S53: Determine whether the number of translation times reaches the total number of translation times, and if so, output that the measurement is completed; otherwise, output that the measurement is not completed.

3. The pipe wall wear detection method based on a laser scanning detector according to claim 1, characterized in that: In S6, the second rate of change is calculated as follows: S61: Calculate the difference between each actual inner diameter and the previous actual inner diameter; S62: Calculating the second rate of change based on the difference and the standard inner diameter; the standard inner diameter is obtained according to the manufacturing specifications of the pipe body; Then the rate of change is Expressed as: in, For the j The actual inner diameter is relative to the The difference in actual inner diameter, is the standard inner diameter, and m is the total number of translations.

4. The pipe wall wear detection method based on a laser scanning detector according to claim 1, characterized in that: In S7, the calculation method of the change rate three is as follows: S71: dividing the intervals measured at the same angle offset into the same set; S72: Calculate the difference between each virtual radius in each set and the virtual radius at the previous position; S73: Calculating the third rate of change based on the difference and the standard inner diameter; Then the rate of change is expressed as: in, For the detector l Rotate at one position k The virtual radius of the second is relative to the Rotate at one position k The difference in virtual radius.

5. A pipe wall wear detection system based on a laser scanning detector, which uses the pipe wall wear detection method based on a laser scanning detector according to any one of claims 1 to 4 to detect the inner wall of the pipe to be tested, characterized in that: It includes: An acquisition module is used to collect the rotation radius of the detector, the diameter of the laser beam, the standard diameter of the pipe to be measured, the detection depth of the pipe to be measured, and multiple distances measured by the detector at different positions; The calculation module is used to: (1) calculate the translation amount of the detector according to the input axial error value and the laser beam diameter; (2) calculate the actual inner diameter of the tube to be measured according to the rotation radius and the multiple spacings; (3) calculate the virtual radius corresponding to each spacing according to the spacing and the actual inner diameter; (4) calculate the change rate of the virtual inner diameter according to the virtual radius and the actual inner diameter; (5) calculate the change rate of the actual inner diameter according to the multiple actual inner diameters; (6) calculate the change rate of the virtual radius at each angular offset according to the angular offset corresponding to each virtual radius; The decision module is used to: (1) determine whether the calculated multiple actual inner diameters exceed a preset inner diameter range, and if so, output a failure signal; (2) determine whether the virtual radius exceeds a preset radius range, and if so, output a failure signal; (3) determine whether the change rate 1 exceeds a preset threshold range 1, and if so, output a failure signal; (4) determine whether the measurement is completed, and if not, output a translation instruction; if the measurement is completed, output an end instruction; (5) determine whether the change rate 2 exceeds a preset threshold range 2, and if so, output a failure signal; (6) determine whether the change rate 2 exceeds a preset threshold range 2, and if so, output a failure signal; (7) determine whether a failure signal is output during the entire detection process, and if no failure signal is output, output a qualified signal; The detector control module is used to: (1) control the detector to rotate one circle according to the ranging angle; (2) control the detector to translate within the tube to be measured according to the translation amount and the translation instruction; (3) control the detector to move to the initial position according to the end instruction.

6. A pipe wall wear detection device based on a laser scanning detector, characterized in that: It includes a laser scanning detector, a memory, a processor, and a computer program stored in the memory and executable on the processor. It is characterized in that the functional modules in the pipe wall wear detection device based on the laser scanning detector are deployed in the manner of the pipe wall wear detection system based on the laser scanning detector according to claim 5. When the processor executes the computer program, it implements the steps of the pipe wall wear detection method based on the laser scanning detector according to any one of claims 1 to 4, and then calculates the actual inner diameter and virtual radius of the pipe body to be measured at different depth positions, determines whether the actual inner diameter and virtual inner diameter of the pipe body to be measured exceed a preset threshold range, and outputs a qualified signal or a unqualified signal based on the judgment result. The laser scanning detector includes a laser ranging sensor and a rotating mechanism. The laser ranging sensor is used to emit a laser detection signal and measure the distance between it and the target object by receiving the echo signal scattered by the target object; the rotating mechanism is fixedly connected to the laser ranging sensor and is used to drive the laser ranging sensor to rotate.

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