An online measurement device and method for all parameters of external threads of petroleum pipes

Abstract

The present invention discloses an online measurement device and method for all parameters of external threads of petroleum tubing, which relates to the field of instruments and equipment in machinery. The online measurement device includes: a driving unit and a measuring unit; the driving unit is connected to the measuring unit, and the driving unit is used to adjust the posture of the measuring unit; the measuring unit is used to perform line scanning on the external threads of petroleum tubing under the drive of the driving unit to obtain a line scanning laser sensor point set of the external threads of petroleum tubing; the line scanning laser sensor point set is used to calculate all parameters of the external threads of petroleum tubing; the full parameters include at least: actual mean diameter, actual pitch and actual taper. The embodiment of the present invention adopts the principle of non-contact line scanning laser measurement to measure the external threads of petroleum tubing, which has the characteristics of high precision, strong flexibility and high speed, and meets the needs of full-parameter production line measurement of external threads of petroleum tubing.

Description

Technical Field

[0001] The present invention relates to the field of mechanical instruments and equipment, and in particular to an online measurement device and method for all parameters of external threads of petroleum tubing. Background Art

[0002] Oil pipe threads are specialized threads used in the petroleum industry to connect pipes such as oil well pipe, casing, and line pipe. These threads are designed to withstand high pressure, high temperature, and corrosive environments, ensuring tightness and joint strength in piping systems. Oil pipe threads are primarily divided into two categories: drill tool joint threads and casing and tubing joint threads.

[0003] Tool joint threads: These threads are used to connect drilling tools and drill string components, such as drill collars, drill pipe, tool stabilizers, and adapters. They typically adhere to API SPEC 7 standards and feature tapered threads that compensate for diameter variations in the connecting parts through axial displacement, achieving high interchangeability and a tight connection.

[0004] Pipe and casing joint threads: These threads are used to connect pipes and casing. They are key components in oil drilling and production, used to connect single pieces of pipe into long strings capable of withstanding high pressures. Pipe and casing threads are typically categorized as round thread (CSG) and cambered thread (BCSG). These threads require couplings and have specific profiles and tapers.

[0005] The design and manufacturing of oil pipe threads are crucial to the connection performance of these pipes and must comply with stringent international standards, such as those of the American Petroleum Institute (API), to ensure reliability in harsh underground environments. If problems arise, repairs can be difficult and, in severe cases, the entire oil pipeline can be scrapped, posing significant safety risks and resulting in incalculable economic losses.

[0006] Currently, spot checks of single thread parameters are commonly used on oil-threaded tubular product production lines. Inspectors use contact-type oil-thread single-parameter inspection instruments to check parameters such as pitch diameter, taper, and pitch. Manual measurement is slow and introduces significant measurement errors, making it impossible to achieve high-speed, high-precision measurement of oil-thread tubular product thread parameters. This testing method is unable to meet the comprehensive external thread parameter inspection requirements of the production line. Summary of the Invention

[0007] The purpose of the present invention is to provide an online measurement device and method, medium and product for all parameters of external threads of petroleum tubing, which can meet the needs of full-parameter production line measurement of external threads of petroleum tubing.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] In one aspect, the present invention provides an online measuring device for all parameters of external threads of petroleum tubular goods, the online measuring device comprising: a driving unit and a measuring unit;

[0010] The driving unit is connected to the measuring unit, and the driving unit is used to adjust the posture of the measuring unit;

[0011] The measuring unit is used to perform line scanning on the external thread of the oil pipe under the drive of the driving unit to obtain a line scanning laser sensor point set of the external thread of the oil pipe; the line scanning laser sensor point set is used to calculate the full parameters of the external thread of the oil pipe; the full parameters include at least: actual pitch diameter, actual pitch and actual taper.

[0012] Optionally, the driving unit is a six-degree-of-freedom robotic arm.

[0013] Optionally, the measuring unit includes: an aluminum profile bracket and two position-adjustable line scanning laser sensor assemblies arranged on the aluminum profile bracket;

[0014] The aluminum profile bracket is connected to the driving unit.

[0015] Optionally, the line scanning laser sensing assembly includes: a floating frame, a floating platform and a line scanning laser sensor;

[0016] The floating frame is connected to the aluminum profile bracket, at least three mutually perpendicular surfaces of the floating platform are connected to the floating frame via adjusting screws, and the line scanning laser sensor is arranged on the floating platform.

[0017] In another aspect, the present invention provides a method for online measurement of all parameters of external threads of petroleum tubular goods, the method comprising:

[0018] Using the above-mentioned online measurement device, a line scanning laser sensor point set of the external thread of the oil pipe is obtained;

[0019] The full parameters of the external thread of the oil pipe are calculated according to the line scanning laser sensor point set; the full parameters at least include: actual pitch diameter, actual pitch and actual taper.

[0020] Optionally, an online measurement device is used to obtain a line scanning laser sensor point set of the external thread of the oil pipe, specifically including:

[0021] Calibrate the measurement unit;

[0022] Fixing the measuring unit on the driving unit;

[0023] Controlling the driving unit to adjust the position of the measuring unit so that the laser direction of the measuring unit is the diameter direction of the external thread of the oil pipe;

[0024] The driving unit is controlled to drive the measuring unit to scan the external thread of the oil tubing along the axial direction of the external thread of the oil tubing, so as to obtain a line scanning laser sensor point set of the external thread of the oil tubing.

[0025] Optionally, the line scanning laser sensor point set includes a first point set and a second point set; the first point set is a point set of the upper half of the external thread of the oil tubing, and the second point set is a point set of the lower half of the external thread of the oil tubing;

[0026] Calculate all parameters of the external thread of oil pipes based on the line scanning laser sensor point set, including:

[0027] According to the theoretical taper of the external thread of the oil tubing, the first point set and the second point set are rotated once so that the directions of the theoretical mid-diameters of the external thread of the oil tubing corresponding to the first point set and the second point set are horizontal;

[0028] Searching for points on the tooth side surface of the external thread of the oil tubing at the first point after rotation, and constructing a first tooth side line of each tooth side surface of the external thread of the oil tubing; the first tooth side line is the tooth side line of the tooth side surface of the upper half of the external thread of the oil tubing;

[0029] Searching for points on the tooth side surface of the external thread of the oil tubing at the second point after rotation, and constructing a second tooth side line of each tooth side surface of the external thread of the oil tubing; the second tooth side line is the tooth side line of the tooth side surface of the lower half of the external thread of the oil tubing;

[0030] Based on the first flank line of each flank surface, a quasi-Newton algorithm is used to construct a first mid-diameter straight line of the external thread of the oil tubular product; the first mid-diameter straight line is the mid-diameter straight line of the upper half of the external thread of the oil tubular product;

[0031] Based on the second flank line of each flank surface, a quasi-Newton algorithm is used to construct a second mid-diameter straight line of the external thread of the oil tubular product; the second mid-diameter straight line is the mid-diameter straight line of the lower half of the external thread of the oil tubular product;

[0032] According to the theoretical taper of the external thread of the oil pipe, the first mid-diameter straight line, the first flank line of each flank, the second mid-diameter straight line and the second flank line of each flank are rotated twice; the direction of the second rotation is opposite to the direction of the first rotation, and the angle of the second rotation is the same as the angle of the first rotation;

[0033] Calculate the actual pitch diameter and actual taper of the external thread of the oil pipe according to the rotated first pitch diameter straight line and the rotated second pitch diameter straight line;

[0034] The actual thread pitch of the external thread of the oil pipe is calculated based on the intersection of the rotated first mid-diameter straight line and the first flank line of each rotated flank surface, and the intersection of the rotated second mid-diameter straight line and the second flank line of each rotated flank surface.

[0035] Optionally, searching for points on the flank surface of the external thread of the petroleum tubular product at the first point after rotation to construct a first flank line of each flank surface of the external thread of the petroleum tubular product specifically includes:

[0036] Calculate the average of the maximum value and the minimum value of the Y axis in the first point set after rotation;

[0037] Searching for points whose Y-axis values ​​are close to the average value in the first point set after rotation to form the first tooth side surface point set; the Y-axis direction is perpendicular to the horizontal direction;

[0038] Obtain n points closest to the sth point in the first tooth side surface point set in the first point set after rotation; s=1, 2, ..., S, where S is the number of points in the first tooth side surface point set;

[0039] The least squares method is used to fit n points to obtain a fitting straight line on the sth tooth side surface of the upper half of the external thread of the petroleum tubular product.

[0040] Optionally, the objective function used in the steps of constructing a first pitch diameter straight line of the external thread of the petroleum tubular product based on the first flank line of each flank surface and constructing a second pitch diameter straight line of the external thread of the petroleum tubular product based on the second flank line of each flank surface using the quasi-Newton algorithm is:

[0041]

[0042] Among them, f is the objective function, dist m-tooth is the Euclidean distance between the intersection of the two adjacent target tooth side lines and the target median diameter line, dist m-groove is the Euclidean distance between the intersections of two adjacent target flank lines and the target mid-diameter straight line; the target flank line is the first flank line or the second flank line, the target mid-diameter straight line is the first mid-diameter straight line or the second mid-diameter straight line, and m is the number of teeth or grooves of the external thread of the oil tubing.

[0043] Optionally, the formula for calculating the actual pitch diameter of the external thread of the oil tubular product based on the rotated first pitch diameter straight line and the rotated second pitch diameter straight line is:

[0044] D=D sensor -y downpitch -y uppitch ;

[0045] Where D is the actual diameter of the external thread of the oil pipe, D sensorTo obtain the distance between the two line scan laser sensors for the first and second point sets, y uppitch is the Y-axis coordinate of the point on the first median diameter line after rotation, y downpitch is the Y-axis coordinate of the point on the second median diameter line after rotation;

[0046] Based on the rotated first and second median diameter lines, the formula for calculating the actual taper of the external thread of the oil pipe is:

[0047]

[0048] Wherein, α is the actual taper of the external thread of the oil pipe, k1 and k2 are the slopes of the first and second median diameter lines after rotation, respectively.

[0049] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0050] An embodiment of the present invention provides an online measurement device and method for all parameters of external threads of petroleum tubing. The online measurement device comprises: a drive unit and a measurement unit; the drive unit is connected to the measurement unit, and the drive unit is used to adjust the position of the measurement unit; the measurement unit is used to perform line scanning on the external threads of the petroleum tubing under the drive of the drive unit to obtain a line scanning laser sensor point set of the external threads of the petroleum tubing; the line scanning laser sensor point set is used to calculate all parameters of the external threads of the petroleum tubing; the full parameters include at least the actual mean diameter, actual pitch, and actual taper. The embodiment of the present invention uses the principle of non-contact line scanning laser measurement to measure the external threads of petroleum tubing, and has the characteristics of high precision, strong flexibility, and high speed, meeting the requirements of full-parameter production line measurement of external threads of petroleum tubing. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0052] Figure 1 A schematic structural diagram of an online measurement device for all parameters of external threads of petroleum tubular goods provided by an embodiment of the present invention;

[0053] Figure 2 A schematic structural diagram of a measurement unit provided in an embodiment of the present invention;

[0054] Figure 3 A schematic diagram of the operation of a line scanning laser sensor according to an embodiment of the present invention;

[0055] Figure 4 A schematic diagram of measuring the external thread of a petroleum pipe provided by an embodiment of the present invention;

[0056] Figure 5 A schematic diagram illustrating the principle of measurement unit calibration provided by an embodiment of the present invention;

[0057] Figure 6 A flow chart of line scanning laser adjustment provided by an embodiment of the present invention;

[0058] Figure 7 Schematic diagram of the line scanning laser thread profile measurement results provided by an embodiment of the present invention.

[0059] Explanation of symbols:

[0060] 1. Drive unit; 2. Measuring unit; 3. Base; 4. Line scan laser sensor; 5. Floating table; 6. Floating frame; 7. Adjusting screw; 8. Aluminum profile bracket; 9. Smooth plug gauge; 10. Laser transmitter; 11. Image receiver; 12. Object to be measured; 13. Limit device; 14. Oil pipe. DETAILED DESCRIPTION

[0061] 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.

[0062] The purpose of the present invention is to provide an online measurement device and method, medium and product for all parameters of external threads of petroleum tubing, which can meet the needs of full-parameter production line measurement of external threads of petroleum tubing.

[0063] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] Example 1

[0065] like Figure 1As shown, this embodiment provides an online measurement device for all parameters of the external thread of a petroleum tubular product. The online measurement device includes: a drive unit 1 and a measurement unit 2; the drive unit 1 is connected to the measurement unit 2, and the drive unit 1 is used to adjust the position of the measurement unit 2; the measurement unit 2 is used to perform line scanning on the external thread of the petroleum tubular product under the drive of the drive unit 1 to obtain a line scanning laser sensor point set of the external thread of the petroleum tubular product; the line scanning laser sensor point set is used to calculate all parameters of the external thread of the petroleum tubular product; the full parameters include at least: actual pitch diameter, actual pitch and actual taper.

[0066] like Figure 1 As shown, in some cases, the above-mentioned online measurement device further includes: a base 3.

[0067] The drive unit 1 is a six-degree-of-freedom robotic arm, which is programmed to control the position and posture of the robotic arm to allow the measurement unit 2 to reach the specified position. The bottom and end joints of the robotic arm are fixed to the base 3 and the measurement unit 2 respectively with bolts.

[0068] like Figure 2 The core components of the measurement unit shown are two non-contact line-scanning laser sensors 4, a precision adjustment platform, and an aluminum profile bracket 8. The precision adjustment platform comprises a floating frame 6, a floating platform 5, and adjustment screws 7. The two line-scanning laser sensors 4 are bolted to the floating platform 5. Manual or powered precision adjustment of the adjustment screws 7 allows for adjustment in the X, Y, and Z directions, as well as in pitch and yaw. The aluminum profile bracket 8 is connected to the floating frame 6 at both ends, forming a complete measurement unit.

[0069] like Figure 3 The line-scan laser sensor 4 shown here is based on the principle of triangulation. A laser transmitter 10 emits a laser line onto the surface of an object 12 to be measured, and an image receiver 11 captures the laser line's presence on the object's surface. This sensor is compact and offers high measurement accuracy, making it a common application in production line inspections.

[0070] The radial line scanning laser in the measurement unit 2 needs to be calibrated before installation on the robotic arm so that the two line scanning laser sensor beams are aligned.

[0071] After the measurement unit is calibrated, Figure 1 As shown, the measuring unit is fixed on the front flange of the robot arm to start measuring. Since the load requirement of the robot arm is less than 10kg, a reasonable design with good rigidity and lightweight structure is required. The aluminum profile bracket 8 is made of 2020 profile and aluminum alloy plate, and the end adapter plate is connected to the end flange of the robot arm by bolts. Figure 4The oil tubing 14 on the production line shown is conveyed by a conveyor to a stopper 13. The initial measurement process begins by guiding the robotic arm to a position near the pipe diameter and positioning the two-line scanning laser sensor within its field of view. Image feedback triggers the robotic arm's movement, adjusting the pitch, yaw, and height degrees of freedom to position the two-line laser sensor in the measurement unit at the pipe diameter. The arm then moves back along the pipe axis, recording its position and beginning measurement of the external thread at the front end of the oil tubing. After the measurement is complete, an algorithm calculates parameters such as the pitch diameter, pitch, flank angle, and taper. Since the thread specifications throughout the pipeline are consistent, subsequent measurements begin directly from the position recorded in the initial measurement.

[0072] The inventive online measuring device for all parameters of external threads of petroleum tubing has a compact structure and can meet the requirements of high-speed and high-precision measurement of external thread parameters of tubing on the production line.

[0073] Example 2

[0074] This embodiment provides a method for online measurement of all parameters of external threads of petroleum tubular goods, the method comprising:

[0075] Step 101, using the online measurement device of Example 1, obtains a line scanning laser sensor point set of the external thread of the oil pipe, specifically including:

[0076] Step 11: Calibrate the measuring unit. The radial line scanning laser in the measuring unit needs to be calibrated before installation on the robotic arm, so that the two line scanning laser sensor beams are aligned. The measuring unit is fixed on a marble platform (or other platform with good flatness). Figure 2 A smooth plug gauge 9 with a similar pitch diameter to the external thread of the oil pipe to be measured is placed vertically between the two line scanning laser sensors 4. The calibration steps are as follows:

[0077] Along Figure 2 The adjusting screws at both ends of the X-axis are adjusted so that the smooth feeler gauge is located in the field of view of the two line scanning laser sensors 4.

[0078] like Figure 5 As shown in (a), the left and right sides are the two scanning laser sensor light spots. Figure 2 The Y-axis adjustment screw shown is adjusted to obtain the minimum values ​​of the two line scanning laser sensors, that is, to place the two laser beams near the radial line of the smooth plug gauge.

[0079] Along Figure 5 The Z-axis adjustment screw shown in (b) is used to adjust the Z-direction height of the two line scanning laser sensors 4 according to the feedback data.

[0080] Fine-tune XZ, such as Figure 5In (c), the pitch angles of the line scanning lasers at both ends are set close to 0. This completes the leveling of the measurement unit.

[0081] Step 12: Secure the measuring unit to the drive unit. The first measurement requires calibrating the pipe diameter. The first pipe is measured using a high-precision coordinate measuring machine (CMM) at a specific cross-section. The calibrated measuring unit is then secured to the front flange of the robotic arm.

[0082] Step 13: Control the driving unit to adjust the position of the measuring unit so that the laser direction of the measuring unit is the diameter direction of the external thread of the oil pipe.

[0083] Guide the robot arm to a position close to the pipe diameter and place the two line scanning laser sensors within the field of view. Figure 6 As shown, the distance calibration process of the line laser sensor is as follows:

[0084] Pitch Angle Adjustment: Image feedback triggers the robot arm's movement, first adjusting the pitch angle. The data points received by the laser sensors at both ends have a certain curvature. The least squares method is used to fit this curvature in real time and calculate the curvature radius. Based on this feedback, the robot arm's pitch position is adjusted. When the diameter exceeds the set curvature radius threshold, the pitch angle approaches 0, completing the pitch adjustment.

[0085] Angular pendulum adjustment: The data points from the two laser sensors are approximated as two straight lines with slopes. The least squares method is used to fit the lines in real time to calculate the slopes, which are fed back to the robotic arm for continuous angular pendulum adjustment. If the absolute value of the slope of the two laser lines increases, the robotic arm is controlled to adjust in the opposite direction. Angular pendulum adjustment is complete when the slope falls below a preset threshold.

[0086] The robot arm is controlled to move repeatedly at low speed in the height direction. When the sum of the measured values ​​of the laser center of gravity points at both end lines is the smallest, the position corresponding to the diameter is found.

[0087] Step 14: Control the driving unit to drive the measuring unit to scan the external thread of the oil tubing along the axial direction of the external thread of the oil tubing, and obtain a line scanning laser sensor point set of the external thread of the oil tubing.

[0088] Record the point sets of the line scanning laser sensors at both ends, and record the position and posture of the robot arm at this time. Fit the upper and lower laser sensor point sets according to the straight line, and the intercepts are b upcalib and b downcalib The first measured oil pipe diameter is D calib . Can calibrate the distance D of two line scanning laser sensors sensor .

[0089] D sensor =D calib+b upcalib +b downcalib

[0090] The robot moves back along the pipe axis, records the position, and begins measuring the oil pipe thread. The oil pipe on the production line passes through the conveyor belt to the limit device, sending a trigger signal. The robot arm moves along the starting and ending positions recorded in the previous step. The line scanning laser sensors at both ends of the measurement unit respectively record the thread tooth curve point set data, including the upper half point set P tsup (ie the first point set) and the lower half point set P tsdown (i.e. the second point set).

[0091] Step 102, calculate the full parameters of the external thread of the oil pipe according to the line scanning laser sensor point set; the full parameters include at least: actual pitch diameter, actual pitch and actual taper. Figure 7 As shown, the thread pitch diameter, major diameter, pitch, flank angle and taper parameters are calculated. The meaning of each parameter is shown in Table 1.

[0092] Table 1 Figure 7 Parameters represented by the numbers

[0093]

[0094] Other parameters involved in this step are shown in Table 2.

[0095] Table 2 Meaning of parameters

[0096]

[0097]

[0098] The specific steps include:

[0099] Step 21: Select the upper and lower points Pts respectively up 、Pts down For the first n data points, calculate the difference between the X coordinates of two adjacent points in the first n points in the upper half of the point set and the difference between the X coordinates of two adjacent points in the first n points in the lower half of the point set, sum them up and calculate their average value r.

[0100] Step 22: According to the theoretical pitch p t Round off to calculate the pitch step Δm: Δm=p t / r.

[0101] Step 23: Based on the theoretical taper value α taper , the point set Pts up and Pts down The data points are rotated clockwise and counterclockwise respectively, with a rotation angle of αtaper / 2. Get the upper and lower half point sets Pts after rotation respectively up '、Pts down '.

[0102] Step 24: In the point set Pts up 'Find the maximum value of point Y max and minimum value Y min , mean Y average =(Y max +Y min ) / 2. Find the Y value closest to Y on each tooth side. average Point Pt, collect tooth side point set Pt angle . Take n2 points near each tooth side surface Pt and use the least square method to fit a straight line, that is, calculate the tooth side line. The slope is k n , the intercept is b n Point set Pts down 'The same calculation is performed.

[0103] Step 25: In the point set Pts up 'Take the X-axis coordinate and the tooth side point set Pt angle The point where the average value of the X-axis coordinates of the first two points Pt is close to the maximum value Y in step 24 max , that is, to determine that the point is on the large diameter line, point Pt major If the value is close to the minimum value Y in step 24 min , that is, the point is determined to be on the minor line, point Pt minor .

[0104] Step 26, with the first Pt major As the initial point, the pitch step m calculated according to step 22 is respectively in the point set Pts up ' and Pts down 'Get the large diameter point set. Calculate the large diameter line by linear fitting. The slope k of the upper half of the large diameter fitting line parameter upmajor ', intercept b upmajor '. The slope k of the fitting straight line parameter of the lower half of the large diameter downmajor ', intercept b downmajor '.

[0105] Step 27: Use the BFGS quasi-Newton algorithm to calculate the upper point set Pts up ', iteratively calculate the thread diameter, set its slope k pitch and intercept b pitch . Its initial iteration value is k upmajor ', b upmajor '. The specific steps are as follows:

[0106] According to the definition of the pitch diameter, the thread tooth width corresponding to the pitch diameter line is equal to the thread tooth groove width. That is, find the minimum value f of the absolute value of the total tooth width minus the total groove width. min .

[0107]

[0108] Where distm-tooth is the Euclidean distance between the intersection points of the tooth flank angles and the median diameter of two adjacent teeth, and distm-groove is the Euclidean distance between the intersection points of the groove flank angles and the median diameter of two adjacent grooves.

[0109] Calculating gradients

[0110] Calculate search direction

[0111] Update matrix B k Get B k+1 :

[0112]

[0113] where s k =x k+1 -x k is the step vector, is the gradient change vector.

[0114] Continuously iterate, when the gradient g k The calculation ends when it is less than the threshold ε, and the slope k of the median line is obtained. pitch and intercept b pitch . According to the X value, we can get Y pitch =k pitch X+b pitch .

[0115] Step 28: For the rotated lower half point set Pts down ', use the method of step 27 to perform iterative calculation to obtain the thread diameter line. The slope k of the upper half of the diameter fitting line parameter uppitch ', intercept b uppitch '. The slope k of the fitting straight line parameter of the lower half of the median diameter downpitch ', intercept b downpitch '.

[0116] Step 29: The upper point set Pts up ', median slope k uppitch ' and the slope of the major diameter line k upmajor 'And the lower half of the point set Pts down ', median slope k downpitch ' and the slope of the major diameter line k downmajor 'Rotate half cone angle α counterclockwise and clockwise respectively taper / 2, that is, we get the point set Pts up 、Pts down , the slope k of the middle diameter and major diameter of the upper part uppitch and k upmajor , the slope k of the middle diameter and major diameter of the lower half downpitch and k downmajor . Reference plane distance dist base Substitute in and get:

[0117] y uppitch =k uppitch *dist base +b uppitch

[0118] y downpitch =k downpitch *dist base +b downpitch

[0119] Calculate the median diameter D

[0120] D=D sensor -y downpitch -y uppitch

[0121] Step 210: Calculate the angle based on the median slope and intercept parameters of the upper and lower parts to obtain the taper value α:

[0122]

[0123] The pitch value of a single tooth is calculated based on the intersection of the pitch diameter slope and intercept parameters of the upper and lower parts with the tooth flank angle fitting line. The pitch value p is obtained by averaging all the pitch values.

[0124] Since the thread specifications on the pipeline are consistent, the pipe diameter calibration step is skipped and the external thread measurement begins directly. The line scan laser sensor can quickly measure five to ten times to eliminate measurement errors introduced by small vibrations.

[0125] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0126] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for online measurement of all parameters of external threads of petroleum tubular goods, characterized in that: The online measurement method comprises: A full-parameter online measurement device for external threads of oil tubing is used to obtain a line scanning laser sensor point set of the external threads of the oil tubing. The full-parameter online measurement device for external threads of oil tubing includes a drive unit and a measurement unit. The drive unit is connected to the measurement unit and is used to adjust the position of the measurement unit. The measurement unit is driven by the drive unit to perform line scanning on the external threads of the oil tubing to obtain a line scanning laser sensor point set of the external threads of the oil tubing. Calculating full parameters of the external thread of the oil pipe according to the line scanning laser sensor point set; the full parameters at least include: actual pitch diameter, actual pitch and actual taper; Obtain the line scanning laser sensor point set of the external thread of the oil pipe, including: Calibrate the measurement unit; Fixing the measuring unit on the driving unit; Controlling the driving unit to adjust the position of the measuring unit so that the laser direction of the measuring unit is the diameter direction of the external thread of the oil pipe; Controlling the driving unit to drive the measuring unit to scan the external thread of the oil tubing along the axial direction of the external thread of the oil tubing to obtain a line scanning laser sensor point set of the external thread of the oil tubing; The line scanning laser sensor point set includes a first point set and a second point set; the first point set is a point set of the upper half of the external thread of the oil tubing, and the second point set is a point set of the lower half of the external thread of the oil tubing; Calculate all parameters of the external thread of oil pipes based on the line scanning laser sensor point set, including: According to the theoretical taper of the external thread of the oil tubing, the first point set and the second point set are rotated once so that the directions of the theoretical mid-diameters of the external thread of the oil tubing corresponding to the first point set and the second point set are horizontal; Searching for points on the tooth side surface of the external thread of the oil tubing at the first point after rotation, and constructing a first tooth side line of each tooth side surface of the external thread of the oil tubing; the first tooth side line is the tooth side line of the tooth side surface of the upper half of the external thread of the oil tubing; Searching for points on the tooth side surface of the external thread of the oil tubing at the second point after rotation, and constructing a second tooth side line of each tooth side surface of the external thread of the oil tubing; the second tooth side line is the tooth side line of the tooth side surface of the lower half of the external thread of the oil tubing; Based on the first flank line of each flank surface, a quasi-Newton algorithm is used to construct a first mid-diameter straight line of the external thread of the oil tubular product; the first mid-diameter straight line is the mid-diameter straight line of the upper half of the external thread of the oil tubular product; Based on the second flank line of each flank surface, a quasi-Newton algorithm is used to construct a second mid-diameter straight line of the external thread of the oil tubular product; the second mid-diameter straight line is the mid-diameter straight line of the lower half of the external thread of the oil tubular product; According to the theoretical taper of the external thread of the oil pipe, the first mid-diameter straight line, the first flank line of each flank, the second mid-diameter straight line and the second flank line of each flank are rotated twice; the direction of the second rotation is opposite to the direction of the first rotation, and the angle of the second rotation is the same as the angle of the first rotation; Calculate the actual pitch diameter and actual taper of the external thread of the oil pipe according to the rotated first pitch diameter straight line and the rotated second pitch diameter straight line; Calculate the actual thread pitch of the external thread of the oil pipe according to the intersection of the first mid-diameter straight line after rotation and the first flank line of each flank surface after rotation, and the intersection of the second mid-diameter straight line after rotation and the second flank line of each flank surface after rotation; The method includes: searching for points on the tooth flanks of the external thread of the oil tubular product at the first point after rotation, and constructing the first tooth flank lines of each tooth flank of the external thread of the oil tubular product. Specifically, the method includes: Calculate the average of the maximum value and the minimum value of the Y axis in the first point set after rotation; Searching for points whose Y-axis values ​​are close to the average value in the first point set after rotation to form a first tooth side surface point set; the Y-axis direction is perpendicular to the horizontal direction; Obtain n points closest to the s-th point in the first tooth side surface point set in the first point set after rotation; s=1, 2, ..., S, where S is the number of points in the first tooth side surface point set; Perform least square fitting on n points to obtain a fitting straight line on the sth tooth side surface of the upper half of the external thread of the petroleum tubular product; Based on the rotated first and second median diameter lines, the formula for calculating the actual taper of the external thread of the oil pipe is: Wherein, α is the actual taper of the external thread of the oil pipe, k1 and k2 are the slopes of the first and second median diameter lines after rotation, respectively.

2. The method for online measurement of all parameters of external threads of petroleum tubular goods according to claim 1 is characterized in that: The driving unit is a six-degree-of-freedom robotic arm.

3. The method for online measurement of all parameters of external threads of petroleum tubular goods according to claim 1 is characterized in that: The measuring unit comprises: an aluminum profile bracket and two position-adjustable line scanning laser sensor assemblies arranged on the aluminum profile bracket; The aluminum profile bracket is connected to the driving unit.

4. The method for online measurement of all parameters of external threads of petroleum tubular goods according to claim 3 is characterized in that: The line scanning laser sensor assembly includes: a floating frame, a floating platform and a line scanning laser sensor; The floating frame is connected to the aluminum profile bracket, at least three mutually perpendicular surfaces of the floating platform are connected to the floating frame via adjusting screws, and the line scanning laser sensor is arranged on the floating platform.

5. The method for online measurement of all parameters of external threads of petroleum tubular goods according to claim 1, characterized in that: Based on the first flank line of each tooth flank, the quasi-Newton algorithm is used to construct the first mid-diameter straight line of the external thread of the oil pipe. Based on the second flank line of each tooth flank, the quasi-Newton algorithm is used to construct the second mid-diameter straight line of the external thread of the oil pipe. The objective function used in the step of constructing the second mid-diameter straight line of the external thread of the oil pipe is: Among them, f is the objective function, dist m-tooth is the Euclidean distance between the intersection points of two adjacent target tooth side lines and the target median diameter line, dist m-groove is the Euclidean distance between the intersections of two adjacent target flank lines and the target mid-diameter straight line; the target flank line is the first flank line or the second flank line, the target mid-diameter straight line is the first mid-diameter straight line or the second mid-diameter straight line, and m is the number of teeth or grooves of the external thread of the oil tubing.

6. The method for online measurement of all parameters of external threads of petroleum tubular goods according to claim 1, characterized in that: Based on the rotated first and second pitch diameter lines, the formula for calculating the actual pitch diameter of the external thread of the oil pipe is: D=D sensor -y downpitch -y uppitch ; Where D is the actual diameter of the external thread of the oil pipe, D sensor To obtain the distance between the two line scan laser sensors for the first and second point sets, y uppitch is the Y-axis coordinate of the point on the first median diameter line after rotation, y downpitch is the Y-axis coordinate of the point on the second median diameter line after rotation.

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