CN115727764A - Method for measuring attitude of spatial complex thin-wall carbon steel process pipeline - Google Patents

Abstract

The invention discloses a method for measuring the attitude of a spatial complex thin-walled carbon steel pipeline, which comprises the following steps: carrying a laser measuring instrument by a mechanical arm, measuring the thin-wall carbon steel process pipeline along the parallel line of the pipeline, inputting measured data into a computer for data extraction, fitting the extracted data by an ellipse fitting method, fitting a spatial straight line according to the central coordinate of the cross section of each ellipse fitting of the pipeline i by a least square method to obtain the direction vector of the ideal axis of the pipeline i, and obtaining the spatial vector included angle alpha of all adjacent pipelines _i According to the angle alpha of the space vector _i The angle of the elbow is determined by the value of (a), and the included angle alpha is selected _i The lengths of the various pipes, the elbows and the beveling angle are obtained. The method can realize accurate butt joint of the spatial thin-wall pipelines and select the correct butt jointThe butt joint elbow improves the welding efficiency, can ensure the welding quality of the spatial thin-wall pipeline, improves the manufacturing and processing efficiency of the thin-wall pipeline and reduces the welding deformation.

Description

Method for measuring attitude of spatial complex thin-wall carbon steel process pipeline

Technical Field

The invention mainly relates to the field of pipeline structure welding, in particular to a method for measuring the attitude of a spatial complex thin-wall carbon steel process pipeline.

Background

The thin-wall pipeline is an important part in the pipeline welding process, the thin-wall pipeline is usually applied to the welding of a space pipeline part, the measurement of the space attitude of the thin-wall pipeline and the angle of an elbow is a very critical problem in the welding process of the space thin-wall pipeline, if the space attitude of the thin-wall pipeline and the angle of the elbow can not be accurately measured, the welded pipeline can be dislocated after the welding is finished, the welding deformation is easily generated, the butt joint precision of the thin-wall pipeline is greatly influenced, and the precision in the butt joint process of the pipelines can not be ensured. In the prior art, a manual measurement mode still needs to be adopted for the space thin-wall pipeline, and the measurement experience of workers needs to be relied on to a great extent, so that errors are easily caused in the butt joint process of the space thin-wall pipeline, and the space thin-wall pipeline needs to be cut again and welded or corrected again, so that the service performance of the space thin-wall pipeline is poor.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for measuring the attitude of a spatial complex thin-wall carbon steel process pipeline.

The technical scheme for realizing the purpose of the invention is as follows:

the invention discloses a method for measuring the attitude of a spatial complex thin-wall carbon steel process pipeline, which comprises the following steps:

clamping the spatial complex thin-wall carbon steel process pipeline to be detected on a workbench, and performing segmented treatment on the spatial complex thin-wall carbon steel process pipeline marked as l ₁ 、l ₂ …l _n Establishing a reference space rectangular coordinate system o-xyz on the workbench, wherein the vertical direction of the workbench is taken as a y axis, the horizontal right direction is taken as an x axis, and the horizontal forward direction is taken as a z axis;

step two, selecting a fixed point o of a space rectangular coordinate system o-xyz on a workbench ₁ The point is a zero coordinate fixed manipulator,carrying a laser measuring instrument by using a manipulator, and measuring the thin-wall carbon steel process pipeline along a parallel line of the pipeline;

step three, after the thin-wall carbon steel process pipeline is measured, outputting the pipeline coordinate values obtained by measurement to a computer, and extracting the coordinates (x) of each measurement point of the ith pipeline _i1 ,y _i1 ,z _i1 )、(x _i2 ,y _i2 ,z _i2 )…(x _in ,y _in ,z _in )；

Step four, passing (x) _i1 ,y _i1 ,z _i1 )、(x _i2 ,y _i2 ,z _i2 )、(x _i3 ,y _i3 ,z _i3 ) Three measuring points are used as cutting planes x 'o' y 'of the pipeline, and each measuring point of the ith pipeline is extracted and projected onto the x' o 'y' plane to obtain plane coordinate values of the measuring points, (x) _i1 ’,y _i1 ’)、(x _i2 ’,y _i2 ’)…(x _in ’,y _in ') fitting the coordinate values of the measuring points obtained in the step three by taking an ellipse as a fitting constraint condition;

step five, the plane coordinate value (x) of the pipeline i in the step four _i1 ’,y _i1 ’)、(x _i2 ’,y _i2 ’)…(x _in ’,y _in ') substituting into the step four ellipse formula, solving the data square sum Q of the pipeline i;

conducting derivation on each parameter { A, B, C, D, E, F } of the data square sum Q of the pipeline i according to an extreme value principle, enabling the value after derivation to be equal to zero, obtaining an optimal solution of each parameter, and solving according to a standard formula of the ellipse to obtain a cross section center coordinate when each ellipse of the pipeline i is fitted;

seventhly, performing space straight line fitting on the section center coordinates of the pipeline i during fitting of each ellipse according to a least square method to obtain a direction vector P of an ideal axis of the pipeline i _i ；

Step eight, respectively making a pipeline l _i+1 、l _i+2 The three to seven steps are repeated to obtain the direction vector P of the ideal axis of all pipelines ₁ 、P ₂ …P _n ；

Step nine, according to the direction vector P of the adjacent pipelines _i (a _i ，b _i ，c _i ),P _i+1 (a _i+1 ，b _i+1 ，c _i+1 ) Obtaining the space vector included angle alpha of all the adjacent pipelines _i ；

Step ten, according to the included angle alpha of the space vector _i The angle of the elbow is determined by the value of (a), and the included angle alpha is selected _i The central point of the corner of the selected elbow is placed in the direction vector P _i ,P _i+1 And P _i ,P _i+1 At the center point of the common perpendicular vector m or the direction vector P _i ,P _i+1 At the intersection of the extension lines;

step eleven, taking the central point of the corner of the elbow as a center, and adjusting the deflection angle theta _i When the extension line of the central line of the two sides of the elbow is connected with the pipeline P _i ,P _i+1 When the center line or the extension line of the angle of deflection theta is intersected, the adjustment of the deflection angle theta is stopped _i Extracting an integral central line obtained by intersecting the central lines of the pipelines;

step twelve, according to the integral central line obtained in the step eleven, designing the design radius R of the pipeline ₀ Obtaining a three-dimensional model of the pipeline and a three-dimensional model of the elbow for the constraint condition;

and step thirteen, taking the intersection point of the central lines of the three-dimensional models of the pipelines and the elbows as a segmentation point, segmenting the three-dimensional model, and respectively obtaining the length and the beveling angle of each pipeline and each elbow.

The invention has the beneficial effects that: by adopting the method, the space thin-wall pipeline can be accurately butted, and the correct butt-joint elbow is selected, so that the welding efficiency is improved, the welding quality of the space thin-wall pipeline can be ensured, the manufacturing and processing efficiency of the thin-wall pipeline is improved, and the welding deformation is reduced.

Drawings

FIG. 1 is a schematic flow chart of a method for measuring attitude of a spatial complex thin-walled carbon steel pipeline according to the present invention;

FIG. 2 is a schematic diagram of the attitude measurement method of the spatial complex thin-walled carbon steel process pipeline of the present invention;

FIG. 3 is a schematic view of the cutting plane x ' o ' y ' of the present invention;

FIG. 4 is a schematic view of a measurement data fit for the pipeline li of the present invention;

FIG. 5 is a schematic diagram of a measurement data fit for pipeline li +1 of the present invention;

fig. 6 is a schematic diagram of the spatial piping elbow arrangement of the present invention.

Detailed Description

The present invention will be further described with reference to the following specific embodiments.

The invention discloses a method for measuring the attitude of a spatial complex thin-walled carbon steel pipeline, which comprises the following steps of:

clamping the spatial complex thin-wall carbon steel process pipeline to be detected on a workbench, and performing segmented treatment on the spatial complex thin-wall carbon steel process pipeline marked as l ₁ 、l ₂ …l _n Establishing a reference space rectangular coordinate system o-xyz on the workbench, wherein the vertical direction of the workbench is taken as a y axis, the horizontal right direction is taken as an x axis, and the horizontal forward direction is taken as a z axis;

step two, selecting a fixed point o of a space rectangular coordinate system o-xyz on a workbench ₁ Fixing the mechanical arm with the point as a zero coordinate, carrying a laser measuring instrument by using the mechanical arm, and measuring the thin-wall carbon steel process pipeline along a parallel line of the pipeline;

step three, after the thin-wall carbon steel process pipeline is measured, outputting the pipeline coordinate values obtained by measurement to a computer, and extracting the coordinates (x) of each measurement point of the ith pipeline _i1 ,y _i1 ,z _i1 )、(x _i2 ,y _i2 ,z _i2 )…(x _in ,y _in ,z _in )；

Step four, passing (x) _i1 ,y _i1 ,z _i1 )、(x _i2 ,y _i2 ,z _i2 )、(x _i3 ,y _i3 ,z _i3 ) Three measuring points are used as cutting planes x 'o' y 'of the pipeline, and each measuring point of the ith pipeline is extracted and projected onto the x' o 'y' plane to obtain plane coordinate values of the measuring points, (x) _i1 ’,y _i1 ’)、(x _i2 ’,y _i2 ’)…(x _in ’,y _in ') fitting the coordinate values of the measuring points obtained in the step three by taking an ellipse as a fitting constraint condition, wherein an ellipse parameter equation can be expressed as:

F(x，y)＝Ax ² +Bxy+Cy ² +Dx+Ey+F

in the formula: { A, B, C, D, E, F } is the parameter value to be solved for the ellipse; (x, y) are the elliptical coordinates of the x ' o ' y ' plane.

Step five, the plane coordinate value (x) of the pipeline i in the step four _i1 ’,y _i1 ’)、(x _i2 ’,y _i2 ’)…(x _in ’,y _in ') into the step four ellipse equation, solving for the sum of squares Q of the data for pipeline i, the calculation equation is as follows:

in the formula: q is the sum of squares of the data for pipeline i, n is the number of data acquisitions, and i is the pipeline number.

Sixthly, according to an extreme value principle, conducting derivation on each parameter { A, B, C, D, E, F } of the data square sum Q of the pipeline i, enabling the value after derivation to be equal to zero, obtaining the optimal solution of each parameter, and solving according to the standard formula of the ellipse to obtain the cross section center coordinate when each ellipse of the pipeline i is fitted;

in the formula: a. b is the value of the major and minor axes of the ellipse.

And seventhly, performing space straight line fitting on the center coordinates of the cross section of the pipeline i when each ellipse is fitted according to a least square method to obtain the direction vector of the ideal axis of the pipeline i. The method comprises the following specific steps

First, setting a space straight line _i The equation is:

in the formula: { G, M, N } is a spatial straight line l _i A parameter value of (d); (x) _i ，y _i ，z _i ) Space straight line l _i The spatial measurement point coordinate values of (a); (x) ₀ ，y ₀ ，z ₀ ) Spatial straight line l _i The initial value of the spatial coordinates of (5) is set to (1,1,1).

Second step, obtaining a space straight line l according to a least square method _i Parametric equations, the formula is as follows:

in the formula: (x) _i ，y _i ，z _i ) Is a spatial straight line l _i The coordinate value of the ith measuring point; n is the number of the measuring points; { G, M, N } is a spatial straight line l _i The parameter value of (2).

Thirdly, according to the extreme value principle, conducting derivatives on the parameters { G, M, N }, enabling the values after conducting derivatives to be equal to zero, obtaining the values of the parameters { G, M, N }, and obtaining the space linear equation l of the pipeline i _i Direction vector P _i 。

Step eight, respectively manufacturing a pipeline l _i+1 、l _i+2 The three to seven steps are repeated to obtain the direction vectors P of the ideal axes of all pipelines ₁ 、P ₂ …P _n ；

Step nine, according to the direction vector P of the adjacent pipelines _i (a _i ，b _i ，c _i ),P _i+1 (a _i+1 ，b _i+1 ，c _i+1 ) Obtaining the space vector included angle alpha of all adjacent pipelines _i According to the calculation formula, the method comprises the following steps:

in the formula: alpha is alpha _i Is the angle between adjacent vectors; (a) _i ，b _i ，c _i ) Is the direction vector of pipeline i; (a) _i+1 ，b _i+1 ，c _i+1 ) Is the direction vector for pipeline i + 1.

Step ten, according to the included angle alpha of the space vector _i The angle of the elbow is determined by the value of (a), and the included angle alpha is selected _i The central point of the corner of the selected elbow is placed in the direction vector P _i ,P _i+1 And P _i ,P _i+1 At the center point of the common perpendicular vector m or the direction vector P _i ,P _i+1 At the intersection of the extension lines;

eleven, taking the central point of the corner of the elbow as a center, and adjusting the deflection angle theta _i When the extension line of the central line of the two sides of the elbow is connected with the pipeline P _i ,P _i+1 When the central lines or the extension lines of the two lines intersect, the adjustment of the deflection angle theta is stopped _i Extracting an integral central line obtained by intersecting the central lines of the pipelines;

step twelve, according to the integral central line obtained in the step eleven, designing the design radius R of the pipeline ₀ Obtaining a three-dimensional model of the pipeline and a three-dimensional model of the elbow for the constraint condition;

and step thirteen, taking the intersection point of the central lines of the three-dimensional models of the pipelines and the elbows as a segmentation point, segmenting the three-dimensional model, and respectively obtaining the length and the beveling angle of each pipeline and each elbow.

Claims (1)

1. A method for measuring the attitude of a spatial complex thin-wall carbon steel process pipeline is characterized by comprising the following steps:

clamping the spatial complex thin-wall carbon steel process pipeline to be detected on a workbench, and performing segmented treatment on the spatial complex thin-wall carbon steel process pipeline marked as l ₁ 、l ₂ …l _n Establishing a reference space rectangular coordinate system o-xyz on the workbench, wherein the vertical direction of the workbench is taken as a y axis, the horizontal right direction is taken as an x axis, and the horizontal forward direction is taken as a z axis;

step two, selecting a fixed point o of a space rectangular coordinate system o-xyz on a workbench ₁ The point is a zero coordinate fixed manipulator, the manipulator carries a laser measuring instrument, and the thin-wall carbon steel process pipeline is measured along the parallel line of the pipeline;

step three, after the thin-wall carbon steel process pipeline is measured, outputting the pipeline coordinate values obtained by measurement to a computer, and extracting the coordinates (x) of each measurement point of the ith pipeline _i1 ,y _i1 ,z _i1 )、(x _i2 ,y _i2 ,z _i2 )…(x _in ,y _in ,z _in )；

Step four, passing (x) _i1 ,y _i1 ,z _i1 )、(x _i2 ,y _i2 ,z _i2 )、(x _i3 ,y _i3 ,z _i3 ) Three measuring points are used as cutting planes x 'o' y 'of the pipeline, and each measuring point of the ith pipeline is extracted and projected onto the x' o 'y' plane to obtain plane coordinate values of the measuring points, (x) _i1 ’,y _i1 ’)、(x _i2 ’,y _i2 ’)…(x _in ’,y _in ') fitting the coordinate values of the measuring points obtained in the step three by taking an ellipse as a fitting constraint condition;

step five, calculating the plane coordinate value (x) of the pipeline i in the step four _i1 ’,y _i1 ’)、(x _i2 ’,y _i2 ’)…(x _in ’,y _in ') substituting into the step four ellipse formula, solving the data square sum Q of the pipeline i;

conducting derivation on each parameter { A, B, C, D, E, F } of the data square sum Q of the pipeline i according to an extreme value principle, enabling the value after derivation to be equal to zero, obtaining an optimal solution of each parameter, and solving according to a standard formula of the ellipse to obtain a cross section center coordinate when each ellipse of the pipeline i is fitted;

seventhly, performing space straight line fitting on the section center coordinates of the pipeline i during fitting of each ellipse according to a least square method to obtain a direction vector P of an ideal axis of the pipeline i _i ；

Step eight, respectively making a pipeline l _i+1 、l _i+2 The three to seven steps are repeated to obtain the direction vector P of the ideal axis of all pipelines ₁ 、P ₂ …P _n ；

Step nine, according to the direction vector P of the adjacent pipelines _i (a _i ，b _i ，c _i ),P _i+1 (a _i+1 ，b _i+1 ，c _i+1 ) Obtaining the space vector included angle alpha of all adjacent pipelines _i ；

Step ten, according to the included angle alpha of the space vector _i The angle of the elbow is determined by the value of (a), and the included angle alpha is selected _i The central point of the corner of the selected elbow is placed in the direction vector P _i ,P _i+1 And P _i ,P _i+1 Or a direction vector P at the center point of the common perpendicular vector m _i ,P _i+1 The intersection of the extended lines;

eleven, taking the central point of the corner of the elbow as a center, and adjusting the deflection angle theta _i When the extension line of the central line of the two sides of the elbow is connected with the pipeline P _i ,P _i+1 When the center line or the extension line of the angle of deflection theta is intersected, the adjustment of the deflection angle theta is stopped _i Extracting an integral central line obtained by intersecting the central lines of the pipelines;

step twelve, according to the integral central line obtained in the step eleven, designing the design radius R of the pipeline ₀ Obtaining a three-dimensional model of the pipeline and a three-dimensional model of the elbow for the constraint condition;

and step thirteen, taking the intersection point of the central lines of the three-dimensional models of the pipelines and the elbows as a segmentation point, segmenting the three-dimensional model, and respectively obtaining the length and the beveling angle of each pipeline and each elbow.

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