H-shaped steel machine tool positioning adjustment method

Abstract

The application discloses a kind of H-shaped steel machine tool processing positioning adjustment methods, belong to H-shaped steel machine tool processing technical field, this processing positioning adjustment method includes installing linear array CCD camera on machine tool workbench, the data acquisition range of linear array CCD camera is adjusted by high-precision rotary table, after shooting is completed, data is transmitted to computer to form the point cloud data of H-shaped steel, the merging point coordinate value is spliced by computer through ICP point cloud splicing algorithm, the profile line of H-shaped steel is determined by weighted least square linear fitting algorithm, the angle and moving distance of center line and machine tool workbench horizontal direction X axis are finally determined, the adjustment of H-shaped steel is realized.The large H-shaped steel center line is consistent with machine center line by adjusting bias E and deflection angle θ, can be conveniently realized bilateral equal machining amount cutting, greatly facilitates processing programming, meanwhile, tool wear can be controlled basically consistent during bilateral milling process, and less downtime tool changing time.

Description

Technical Field

[0001] This invention belongs to the field of H-beam machine tool processing technology, and particularly relates to a positioning and adjustment method for H-beam machine tool processing. Background Technology

[0002] With the continuous development of offshore oil and natural gas resources in my country, the demand for energy is increasing daily, urgently requiring revolutionary innovation and technological breakthroughs in the field of marine engineering equipment. Large offshore oil and gas platforms require a large number of steel structure modules during construction, and the production of these modules utilizes a large amount of large H-beams. Large H-beams are generally welded components, and defects such as unevenness, bending, and burrs exist on the edges and corners of the flanges. If these defects are not repaired before painting, they will significantly affect the painting quality. Traditional flange grinding methods use manual hand-held angle grinders, which are not only inefficient and costly but also dangerous. Large steel flanges require machining to ensure better painting operations.

[0003] Large H-beams are typically several meters or even more than ten meters long. They are hoisted or rolled onto machine tools. To facilitate machining, the position of the H-beams needs to be adjusted. Traditional tape measure measurement is not only inefficient and inaccurate, but also requires tedious manual calculations.

[0004] Therefore, there is an urgent need to design a positioning and adjustment method for H-beam machine tool processing to solve the problems mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a method for positioning and adjusting H-beam milling, which facilitates double-sided equal-volume cutting, greatly simplifies machining programming, and allows for consistent tool wear during double-sided milling, minimizing downtime for tool changes. This solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the specific technical solution of the H-beam steel machine tool machining positioning adjustment method of the present invention is as follows:

[0007] A method for positioning and adjusting H-beams during machine tool processing includes the following steps:

[0008] S1. Place the H-beam on the machine tool workbench. Install standard measuring points on the upper and lower sides of the machine tool workbench, marked as P1 and P2. Install standard measuring points on the front and rear sides of the machine tool workbench, marked as P3 and P4.

[0009] S2. A machine tool column is installed on the machine tool worktable. A CCD camera is installed on the machine tool column. The CCD camera can rotate relative to the machine tool worktable to change the shooting angle of the CCD camera.

[0010] S3. Establish a coordinate system XOY, with the installation point of the machine tool column as the origin O, the center line of the length direction of the machine tool worktable as the X-axis, the width direction as the Y-axis, and the center line of the machine tool column as the Z-axis.

[0011] S4. Measure the installation height H0 of the CCD camera, the length L of the H-beam, the width W of the H-beam, and the height H of the H-beam;

[0012] S5. Adjust the data acquisition range of the CCD camera, set standard measurement point P1 as the starting point of vertical shooting, set standard measurement point P2 as the ending point of vertical shooting, set standard measurement point P3 as the starting point of front and back shooting, and set standard measurement point P4 as the ending point of front and back shooting.

[0013] S6. Set the angular velocity of the CCD camera to the position of one vertical rotation. The angular velocity of one forward and backward rotation is Set the shooting path of the CCD camera. The vertical shooting path is from standard measurement point P1 to standard measurement point P2, and the front-back shooting path is from standard measurement point P3 to standard measurement point P4.

[0014] S7. When the CCD camera is aimed at the initial point P1 for shooting, with angular velocity... Take pictures along the vertical shooting path. When the CCD camera is aligned with the initial point P3 shooting position, take pictures at an angular velocity... Take photos along the shooting path, and store the data in the computer after the photos are taken;

[0015] S8. Perform pixel point cloud preprocessing on the obtained image, select the points on the outer edge of the H-beam in the image as image stitching points, and calculate the coordinate values ​​of the H-beam image merging points in the image based on the imaging principle of the CCD camera.

[0016] S9. In the computer, the coordinate values ​​of the merged points are spliced ​​using the ICP point cloud splicing algorithm, and then the point cloud data is denoised to form the point cloud data of the H-beam.

[0017] S10. The complete H-beam point cloud data obtained in S7 is linearly fitted using a weighted least squares linear fitting algorithm to obtain the outlines of the H-beam L1, L2, L3 and L4.

[0018] S11. Based on the length and width of the H-beam, select L1 and L3 as the reference, and use the nearest neighbor search method within radius R to retrieve the center point of the H-beam's outline. After determining the center point, use the weighted least squares linear fitting algorithm again to obtain the center line L0 of the H-beam's outline.

[0019] S12. Calculate the coordinates O1(x) of the intersection point based on the centerline L0 and the outlines L2 and L4 of the H-beam.o1 y o1 H) and O2(x) o2 y o2 , H), calculate the angle with the horizontal X-axis based on the coordinates of the intersection point, which is the deflection angle, denoted as θ, and the offset E of the left endpoint from the horizontal axis, calculated using the following formula:

[0020]

[0021] In the formula, E is the offset of the endpoint from the horizontal axis, θ is the deflection angle, and θ is the angle between the intersection point and the horizontal X-axis calculated from the coordinates of the intersection point.

[0022] S13. Adjust the H-beam according to the offset E and the deflection angle θ. First, shift the left end point of the center line of the H-beam by an offset E, and then rotate the axis of the H-beam by θ so that the center line is always aligned with the center line of the machine tool table.

[0023] Furthermore, in S2, a turntable is installed on the machine tool column for mounting a CCD camera. The turntable can rotate relative to the machine tool worktable to change the shooting angle of the CCD camera.

[0024] Furthermore, in S4, a laser measuring instrument is used for measurement.

[0025] Furthermore, in S5, when the CCD camera can capture point P1, the angle between the shooting angle and the Z-axis is marked as α1; when the CCD camera can capture point P2, the angle between the shooting angle and the Z-axis is marked as α2; when the CCD camera can capture point P3, the angle between the shooting angle and the Z-axis is marked as β1; and when the CCD camera can capture point P4, the angle between the shooting angle and the Z-axis is marked as β2.

[0026] Furthermore, in S8, point P on the outer edge of the H-beam in the image. i P i+1 P i+2 and P i+3 These are the image stitching points.

[0027] Furthermore, S8 includes the following steps:

[0028] S81. Determine the image splicing point P of the H-beam. i P i+1 P i+2 and P i+3 Location;

[0029] S82. Calculate the vertical and horizontal rotation angles of each splicing point. and front and rear corners

[0030] In the formula, m is the number of times the high-precision rotary table rotates up and down, and n is the number of times the high-precision rotary table rotates back and forth.

[0031] S83. Calculate the image stitching point P from the CCD camera's focus to the H-beam based on the CCD camera's imaging principle. i Distance L i The formula is:

[0032] L i =f i H / H0i = 1, 2, 3...

[0033] In the formula, L i f is the distance from the CCD camera focus to the image stitching point on the H-beam. i H is the focal length of the CCD camera during the i-th shot, H is the height of the steel profile, H0 is the installation height of the CCD camera, and i is the sequence number of the i-th shot.

[0034] S84. Based on the distance L from the CCD camera focus to the image stitching point on the H-beam. i and the vertical rotation angle α i and front and rear turning angles β i The coordinates of the merged point Pi in the image are calculated using the following formula:

[0035] P i =(L i sinα i cosβ i L i sinα i sinβ i H)

[0036] In the formula, P i Let L be the coordinates of the merging point. i α is the distance from the CCD camera focus to the image stitching point on the H-beam. i β is the angle of vertical rotation of the CCD camera. i H represents the angle at which the CCD camera rotates forward and backward, and H represents the height of the steel profile.

[0037] Furthermore, S9 includes the following steps:

[0038] S91. Set the critical angle ρ in the computer. th The stitching error d' is calculated by selecting point cloud data from any two adjacent images as the point cloud data to be merged, where A is the target point cloud data and B is the stitched point cloud data.

[0039] S92. Randomly select three points P in the target point cloud data A. i P i+1 P i+2Construct a plane QA, and draw the normal η of the plane through any point in it. pi ;

[0040] S93. Randomly select three points Q from the stitched point cloud data B. i Q i+1 Q i+2 Form a plane, and draw the normal η of the plane through a point in it. Qi ;

[0041] S94, Calculate the normal η pi With normal η Qi The included angle ρ between them, if the included angle ρ is greater than the set critical angle ρ th Then return to S93 and reselect any three points in the stitched point cloud data B to create the plane normal η. Qi until the normal η pi With normal η Qi The included angle ρ between them is less than or equal to the set critical angle ρ. th Record the plane at this moment as Q. v ;

[0042] S95, through plane Q v Different points on the plane Q respectively A Draw perpendicular lines with distances d1, d2, ... d 1+v Determine the minimum distance, d. iv =min(d1, d2…d 1+v ), and based on the minimum distance d iv Determine the coordinates d of the corresponding foot of the perpendicular. iv (x iv y iv );

[0043] S96. Based on different perpendicular foot coordinate values ​​d iv (x iv y iv The rotation angle R and translation distance t can be calculated using the following formula:

[0044]

[0045] In the formula, f(R,t) is a function of rotation angle R and translation distance t, where R is the rotation angle, t is the translation distance, k is the number of nearest neighbor pairs on plane Qv, and x_iv and y_iv are the perpendicular coordinates.

[0046] S97. Based on the rotation angle R and translation distance t, translate and rotate the spliced ​​point cloud data set B to obtain a new corresponding point cloud set B';

[0047] S98. Construct a plane Q from the points on the new corresponding point cloud set B'. AFind the perpendicular line to the plane and calculate the distance D from the point to the plane. i According to each distance D i Calculate the average distance D between the new corresponding point cloud set B' and the target point set A. 平均 ;

[0048]

[0049] In the formula, D 平均 D is the average distance. i For a point to plane Q A The distance, where N is the number of points;

[0050] S99, If D 平均 If the error is less than the set splicing error d', stop the iteration; otherwise, return to S95 until the termination condition D is met. 平均 Less than the set splicing error d';

[0051] S910. Update the stitched point cloud data to the target point cloud data A, update the reselected point cloud data to the stitched point cloud data B, and return to S91 to stitch the point cloud data of the H-beam until all the image point cloud data are stitched together, and obtain all the point cloud data of the H-beam.

[0052] S911. Denoise all point cloud data of the spliced ​​H-beams, especially for the L-beams. X -R≤X i ≤L X +L+R,-W / 2-T≤Y i Point cloud data within the range of ≤W / 2+T are retained, and those outside the range are discarded. After the discarding is completed, the complete point cloud data of the H-beam is obtained.

[0053] In the formula, R is the allowable reserve value in the length direction and T is the allowable reserve value in the width direction. The reserve value should be set in the computer according to the requirements.

[0054] Furthermore, S10 includes the following steps:

[0055] S101, Set the point cloud data P for each H-beam. i Weighting coefficient ω i ;

[0056]

[0057] In the formula, ω i For point cloud data weighting system, x i The horizontal x-coordinate value of the point cloud data;

[0058] S102. Constructing the least-squares linear fitting function for the H-beam profile:

[0059]

[0060] In the formula, l i Let a be the H-beam profile function, where a is the function slope, b is the intercept, n is the number of fitting points, and x is the x-axis. i y i These are the coordinates of the fitted point.

[0061] S103. Calculate the a and b values ​​of the weighted least squares linear fitting algorithm function for the H-beam profile.

[0062]

[0063] S104. Repeat S102 and S103 to calculate the outline of the H-beam, which are marked as L1, L2, L3 and L4 respectively.

[0064] Furthermore, in S11, the Octree search algorithm is used for retrieval.

[0065] Furthermore, the retrieval radius using the Octree search algorithm is R = W / 2.

[0066] The present invention has the following advantages: By installing a CCD camera on the machine tool, the CCD camera obtains the deflection angle between the center line of the large H-beam and the axis of motion of the machine tool, and the offset between the center line of the large H-beam and the center line of the machine tool. By adjusting these two parameters, the center line of the large H-beam coincides with the axis of motion of the machine tool, and the center line of the large H-beam is aligned with the center line of the machine tool. This facilitates double-sided equal machining, greatly facilitating machining programming. At the same time, it can control the tool wear to be basically uniform during the double-sided milling process, reducing downtime for tool changing. Attached Figure Description

[0067] Figure 1 This is a flowchart illustrating the processing positioning adjustment method of the present invention;

[0068] Figure 2 This is a front view of the measurement structure of the CCD camera in this invention;

[0069] Figure 3 This is a top view of the measurement structure of the CCD camera in this invention;

[0070] Figure 4 This is a schematic diagram of the measurement of H-beam splicing points using CCD imaging according to the present invention;

[0071] Figure 5 This is a schematic diagram of the outline of the H-shaped steel structure of the present invention;

[0072] The markings in the diagram are as follows: 1. Machine tool worktable; 2. Machine tool column; 3. Turntable; 4. CCD camera; 5. Standard measuring point; 6. H-beam. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0074] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0075] The following is a reference to the appendix. Figure 1 To be continued Figure 5 This invention describes a method for positioning and adjusting H-beams in machine tool processing.

[0076] Currently, large H-beams are generally several meters or even more than ten meters long. They are hoisted or rolled onto machine tools. To facilitate machining, the position of the H-beams needs to be adjusted. Traditional tape measure measurement is not only inefficient and inaccurate, but also requires tedious manual calculations.

[0077] Therefore, the positioning and adjustment method for H-beam steel machining on this machine tool includes the following steps:

[0078] S1. Place the H-beam 6 on the machine tool workbench 1. Install standard measuring points 5 on the upper and lower sides of the machine tool workbench 1, marked as P1 and P2. Install standard measuring points 5 on the front and rear sides of the machine tool workbench 1, marked as P3 and P4.

[0079] S2. A machine tool column 2 is installed on the machine tool worktable 1. A CCD camera 4 is installed on the machine tool column 2. The CCD camera 4 can rotate relative to the machine tool worktable 1 to change the shooting angle of the CCD camera 4.

[0080] Specifically, a turntable 3 is installed on the machine tool column 2. The turntable 3 is used to install the CCD camera 4. The turntable 3 can rotate relative to the machine tool worktable 1 to change the shooting angle of the CCD camera 4.

[0081] Preferably, the turntable 3 is a high-precision turntable 3, which can drive the CCD camera 4 to rotate back and forth, and can also drive the CCD camera 4 to rotate up and down.

[0082] Specifically, CCD camera 4 is a linear CCD camera.

[0083] S3. Establish a coordinate system XOY, with the installation point of the machine tool column 2 as the origin O, the center line of the length direction of the machine tool worktable 1 as the X-axis, the width direction as the Y-axis, and the center line of the machine tool column 2 as the Z-axis.

[0084] S4. Measure the installation height H0 of CCD camera 4, the length L of H-beam 6, the width W of H-beam 6, and the height H of H-beam 6;

[0085] Specifically, a laser measuring instrument is used for measurement. In other embodiments of the present invention, other measuring instruments may also be used for measurement.

[0086] S5. Adjust the data acquisition range of CCD camera 4, set standard measurement point 5P1 as the starting point of vertical shooting, set standard measurement point 5P2 as the ending point of vertical shooting, set standard measurement point 5P3 as the starting point of front and back shooting, and set standard measurement point 5P4 as the ending point of front and back shooting.

[0087] Specifically, when CCD camera 4 can capture point P1, the angle between the shooting angle and the Z-axis is marked as α1; when CCD camera 4 can capture point P2, the angle between the shooting angle and the Z-axis is marked as α2; when CCD camera 4 can capture point P3, the angle between the shooting angle and the Z-axis is marked as β1; and when CCD camera 4 can capture point P4, the angle between the shooting angle and the Z-axis is marked as β2.

[0088] S6. Set the angular velocity of the CCD camera 4 for one vertical rotation as... The angular velocity of one forward and backward rotation is Set the shooting path of CCD camera 4. The vertical shooting path is from standard measurement point 5P1 to standard measurement point 5P2, and the front and back shooting path is from standard measurement point 5P3 to standard measurement point 5P4.

[0089] S7. When the CCD camera 4 is aligned with the initial point P1 for shooting, at an angular velocity... Take pictures along the vertical shooting path. When CCD camera 4 is aligned with the initial point P3, take pictures at an angular velocity... Take photos along the shooting path, and store the data in the computer after the photos are taken;

[0090] S8. Perform pixel point cloud preprocessing on the obtained image, select the points on the outer edge of H-beam 6 in the image as image stitching points, and calculate the coordinate values ​​of the image merging points of H-beam 6 in the image based on the imaging principle of CCD camera 4.

[0091] Specifically, point P on the outer edge of H-beam 6 in the image. i Pi+1 P i+2 and P i+3 For image stitching points;

[0092] S8 includes the following steps:

[0093] S81. Determine the image splicing point P of the H-beam steel. i P i+1 P i+2 and P i+3 Location;

[0094] S82. Calculate the vertical and horizontal rotation angles of each splicing point. and front and rear corners

[0095] In the formula, m is the number of times the high-precision rotary table 3 rotates up and down, and n is the number of times the high-precision rotary table 3 rotates forward and backward.

[0096] S83. Based on the imaging principle of CCD camera 4, calculate the image stitching point P from the focus of CCD camera 4 to the H-beam 6. i Distance L i The formula is:

[0097] L i = f i·H / H0 i=1,2,3...

[0098] In the formula, L i f is the distance from the focal point of CCD camera 4 to the image stitching point on H-beam 6. i H is the focal length of the CCD camera 4 during the i-th shot, H is the height of the steel profile, H0 is the installation height of the CCD camera 4, and i is the sequence number of the i-th shot.

[0099] S84. Based on the distance L from the focal point of CCD camera 4 to the image stitching point on H-beam 6. i and the vertical rotation angle α i and front and rear turning angles β i The coordinates of the merged point Pi in the image are calculated using the following formula:

[0100] P i =(L i sinα i cosβ i L i sinα i sinβ i H)

[0101] In the formula, P i Let L be the coordinates of the merging point. i α is the distance from the focal point of CCD camera 4 to the image stitching point on H-beam 6.i β is the angle at which the CCD camera 4 rotates up and down. i H represents the angle at which the CCD camera 4 rotates forward and backward, and H represents the height of the steel profile.

[0102] S9. In the computer, the coordinate values ​​of the merged points are stitched together using the ICP point cloud stitching algorithm, and then the point cloud data is denoised to form the point cloud data of H-beam 6.

[0103] S9 includes the following steps:

[0104] S91. Set the critical angle ρ in the computer. th The stitching error d' is calculated by selecting point cloud data from any two adjacent images as the point cloud data to be merged, where A is the target point cloud data and B is the stitched point cloud data.

[0105] S92. Randomly select three points P in the target point cloud data A. i P i+1 P i+2 Construct a plane QA, and draw the normal η of the plane through any point in it. pi ;

[0106] S93. Randomly select three points Q from the stitched point cloud data B. i Q i+1 Q i+2 Form a plane, and draw the normal η of the plane through a point in it. Qi ;

[0107] S94, Calculate the normal η pi With normal η Qi The included angle ρ between them, if the included angle ρ is greater than the set critical angle ρ th Then return to S93 and reselect any three points in the stitched point cloud data B to create the plane normal η. Qi until the normal η pi With normal η Qi The included angle ρ between them is less than or equal to the set critical angle ρ. th Record the plane at this moment as Q. v ;

[0108] S95, through plane Q v Different points on the plane Q respectively A Draw perpendicular lines with distances d1, d2, ... d 1+v Determine the minimum distance, d. iv =min(d1, d2…d 1+v ), and based on the minimum distance d iv Determine the coordinates d of the corresponding foot of the perpendicular. iv (x iv y iv );

[0109] S96. Based on different perpendicular foot coordinate values ​​d iv (x iv y iv The rotation angle R and translation distance t can be calculated using the following formula:

[0110]

[0111] In the formula, f(R,t) is a function of rotation angle R and translation distance t, where R is the rotation angle, t is the translation distance, k is the number of nearest neighbor pairs on plane Qv, and x_iv and y_iv are the perpendicular coordinates.

[0112] S97. Based on the rotation angle R and translation distance t, translate and rotate the spliced ​​point cloud data set B to obtain a new corresponding point cloud set B';

[0113] S98. Construct a plane Q from the points on the new corresponding point cloud set B'. A Find the perpendicular line to the plane and calculate the distance D from the point to the plane. i According to each distance D i Calculate the average distance D between the new corresponding point cloud set B' and the target point set A. 平均 ;

[0114]

[0115] In the formula, D 平均 D is the average distance. i For a point to plane Q A The distance, where N is the number of points;

[0116] S99, If D 平均 If the error is less than the set splicing error d', stop the iteration; otherwise, return to S95 until the termination condition D is met. 平均 Less than the set splicing error d';

[0117] S910. Update the stitched point cloud data to the target point cloud data A, update the reselected point cloud data to the stitched point cloud data B, and return to S91 to stitch the point cloud data of H-beam 6 until all image point cloud data are stitched together, and obtain all the point cloud data of H-beam 6.

[0118] S911. Denoise the point cloud data of all H-beams 6 after splicing, for the L... X -R≤X i ≤L X +L+R,-W / 2-T≤Y i Point cloud data within the range of ≤W / 2+T are retained, and those outside the range are discarded. After the discarding is completed, the complete point cloud data of H-beam 6 is obtained.

[0119] In the formula, R is the allowable reserve value in the length direction and T is the allowable reserve value in the width direction. The reserve value should be set in the computer according to the requirements.

[0120] S10. The complete H-beam 6 point cloud data obtained in S7 is linearly fitted using the weighted least squares linear fitting algorithm to obtain the outline lines L1, L2, L3 and L4 of H-beam 6.

[0121] S10 includes the following steps:

[0122] S101, Set the point cloud data P for each point cloud of H-beam 6. i Weighting coefficient ω i ;

[0123]

[0124] In the formula, ω i For point cloud data weighting system, x i The horizontal x-coordinate value of the point cloud data;

[0125] S102. Constructing the least-squares linear fitting function for the H-beam steel profile:

[0126]

[0127] In the formula, l i Here is the H-beam profile function, where a is the slope, b is the intercept, n is the number of fitted points, and x is the x-axis. i y i These are the coordinates of the fitted point.

[0128] S103. Calculate the a and b values ​​of the weighted least squares linear fitting algorithm function for the H-beam 6 profile.

[0129]

[0130] S104, repeat S102 and S103 to calculate the outline of H-beam 6, which are marked as L1, L2, L3 and L4 respectively.

[0131] S11. Based on the length and width of H-beam 6, select L1 and L3 as the reference, and use the nearest neighbor search method within radius R to retrieve the center point of the outline of H-beam 6. After determining the center point, use the weighted least squares linear fitting algorithm again to obtain the center line L0 of the outline of H-beam 6.

[0132] Specifically, the Octree search algorithm is used for retrieval. In other embodiments of the present invention, other algorithms may also be used for retrieval.

[0133] S12. Calculate the coordinate value O1(x) of the intersection point based on the centerline L0 and contour lines L2 and L4 of the H-beam 6 profile. o1 y o1 H) and O2(x) o2 y o2 , H), calculate the angle with the horizontal X-axis based on the coordinates of the intersection point, which is the deflection angle, denoted as θ, and the offset E of the left endpoint from the horizontal axis, calculated using the following formula:

[0134]

[0135] In the formula, E is the offset of the endpoint from the horizontal axis, θ is the deflection angle, and θ is the angle between the intersection point and the horizontal X-axis calculated from the coordinates of the intersection point.

[0136] S13. Adjust the H-beam 6 according to the offset E and the deflection angle θ. First, shift the left end point of the center line of the H-beam 6 by an offset E, and then rotate the axis of the H-beam 6 by θ so that the center line is always aligned with the center line of the machine tool worktable 1.

[0137] The present invention has the following advantages: By installing a CCD camera 4 on the machine tool, the CCD camera 4 obtains the deflection angle between the center line of the large H-beam and the axis of motion of the machine tool, and the offset between the center line of the large H-beam 6 and the center line of the machine tool. By adjusting these two parameters, the center line of the large H-beam 6 is made to coincide with the axis of motion of the machine tool, and the center line of the large H-beam 6 is aligned with the center line of the machine tool. This facilitates double-sided equal machining, greatly facilitating machining programming. At the same time, it can control the tool wear to be basically consistent during the double-sided milling process, reducing downtime for tool changing.

[0138] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for positioning and adjusting H-beams during machine tool processing, characterized in that, Includes the following steps: S1. Place the H-beam on the machine tool workbench. Install standard measuring points on the upper and lower sides of the machine tool workbench, marked as P1 and P2. Install standard measuring points on the front and rear sides of the machine tool workbench, marked as P3 and P4. S2. A machine tool column is installed on the machine tool worktable. A CCD camera is installed on the machine tool column. The CCD camera can rotate relative to the machine tool worktable to change the shooting angle of the CCD camera. S3. Establish a coordinate system XOY, with the installation point of the machine tool column as the origin O, the center line of the length direction of the machine tool worktable as the X-axis, the width direction as the Y-axis, and the center line of the machine tool column as the Z-axis. S4. Measure the installation height H0 of the CCD camera, the length L of the H-beam, the width W of the H-beam, and the height H of the H-beam; S5. Adjust the data acquisition range of the CCD camera, set point P1 as the starting point of vertical shooting, point P2 as the ending point of vertical shooting, point P3 as the starting point of front and back shooting, and point P4 as the ending point of front and back shooting. S6. Set the angular velocity of the CCD camera to ø1 for one vertical rotation and ø2 for one forward and backward rotation. Set the shooting path of the CCD camera. The vertical shooting path is from standard measurement point P1 to standard measurement point P2, and the forward and backward shooting path is from standard measurement point P3 to standard measurement point P4. S7. When the CCD camera is aimed at the initial point P1, take pictures along the up and down shooting path with an angular velocity ø1. When the CCD camera is aimed at the initial point P3, take pictures along the front and back shooting path with an angular velocity ø2. After taking pictures, store the data in the computer. S8. Perform pixel point cloud preprocessing on the obtained image, select the points on the outer edge of the H-beam in the image as image stitching points, and calculate the coordinate values ​​of the H-beam image merging points in the image based on the imaging principle of the CCD camera. S9. In the computer, the coordinate values ​​of the merged points are spliced ​​using the ICP point cloud splicing algorithm, and then the point cloud data is denoised to form the point cloud data of the H-beam. S10. The complete H-beam point cloud data obtained in S7 is linearly fitted using a weighted least squares linear fitting algorithm to obtain the outlines of the H-beam L1, L2, L3 and L4. S11. Based on the length and width of the H-beam, select L1 and L3 as the reference, and use the nearest neighbor search method within radius R to retrieve the center point of the H-beam's outline. After determining the center point, use the weighted least squares linear fitting algorithm again to obtain the center line L0 of the H-beam's outline. S12. Calculate the coordinate value O1 (x) of the intersection point based on the centerline L0 and the outlines L2 and L4 of the H-beam. o1 y o1 H) and O2 (x) o2 y o2 Based on the coordinates of the intersection point, calculate the angle with the horizontal X-axis, which is the deflection angle, denoted as θ, and the offset E of the left endpoint from the horizontal axis. The calculation formula is as follows: In the formula, E is the offset of the endpoint from the horizontal axis, θ is the deflection angle, and θ is the angle between the intersection point and the horizontal X-axis calculated from the coordinates of the intersection point. S13. Adjust the H-beam according to the offset E and the deflection angle θ. First, shift the left end point of the center line of the H-beam by an offset E, and then rotate the axis of the H-beam by θ so that the center line is always aligned with the center line of the machine tool table.

2. The method for positioning and adjusting H-beam machine tool processing according to claim 1, characterized in that, In S2, a turntable is installed on the machine tool column. The turntable is used to mount the CCD camera. The turntable can rotate relative to the machine tool worktable to change the shooting angle of the CCD camera.

3. The method for positioning and adjusting H-beam machine tool processing according to claim 1, characterized in that, In S4, a laser measuring instrument is used for measurement.

4. The method for positioning and adjusting H-beam machine tool processing according to claim 1, characterized in that, In S5, when the CCD camera can capture point P1, the angle between the shooting angle and the Z-axis is marked as α1. When the CCD camera can capture point P2, the angle between the shooting angle and the Z-axis is marked as α2. When the CCD camera can capture point P3, the angle between the shooting angle and the Z-axis is marked as β1. When the CCD camera can capture point P4, the angle between the shooting angle and the Z-axis is marked as β2.

5. The method for positioning and adjusting H-beam machine tool processing according to claim 1, characterized in that, In S8, point P is located at the outer edge of the H-beam in the image. i P i+1 P i+2 and P i+3 Let i be the image stitching point, where i is the sequence number of the i-th image capture.

6. The method for positioning and adjusting H-beam machine tool processing according to claim 5, characterized in that, S8 includes the following steps: S81. Determine the image splicing point P of the H-beam. i P i+1 P i+2 and P i+3 Location; S82. Calculate the vertical rotation angle α at each splicing point. i =m×ø1 and front and rear rotation angles β i =n×ø2; In the formula, m is the number of times the high-precision rotary table rotates up and down, and n is the number of times the high-precision rotary table rotates back and forth. S83. Calculate the image stitching point P from the CCD camera's focus to the H-beam based on the imaging principle of the CCD camera. i Distance L i The formula is: In the formula, L i f is the distance from the CCD camera focus to the image stitching point on the H-beam. i H is the focal length of the CCD camera during the i-th shot, H is the height of the steel profile, H0 is the installation height of the CCD camera, and i is the sequence number of the i-th shot. S84. Based on the distance L from the CCD camera focus to the image stitching point on the H-beam. i and the vertical rotation angle α i and front and rear turning angles β i The coordinates of the merged point Pi in the image are calculated using the following formula: In the formula, P i Let L be the coordinates of the merging point. i α is the distance from the CCD camera focus to the image stitching point on the H-beam. i β is the angle of vertical rotation of the CCD camera. i H represents the angle at which the CCD camera rotates forward and backward, and H represents the height of the steel profile.

7. The method for positioning and adjusting H-beam machine tool processing according to claim 1, characterized in that, S9 includes the following steps: S91. Set the critical angle ρ in the computer. th The stitching error d' is calculated by selecting point cloud data from any two adjacent images as the point cloud data to be merged, where A is the target point cloud data and B is the stitched point cloud data. S92. Randomly select three points in the target point cloud data A. , , Construct a plane QA, and draw the normal η of the plane through any point in it. pi ; S93. Randomly select three points in the stitched point cloud data B. , , Form a plane, and draw the normal η of the plane through a point in it. Qi ; S94, Calculate the normal η pi With normal η Qi The included angle ρ between them, if the included angle ρ is greater than the set critical angle ρ th Then return to S93 and reselect any three points in the stitched point cloud data B to create the plane normal η. Qi until the normal η pi With normal η Qi The included angle ρ between them is less than or equal to the set critical angle ρ. th Record the plane at this moment as Q. v ; S95, through plane Q v Different points on the plane Q respectively A Draw perpendicular lines with distances d1, d2, ... d 1+v Determine the minimum distance, d. iv =min(d1, d2, ... d 1+v ), and based on the minimum distance d iv Determine the coordinates d of the corresponding foot of the perpendicular. iv (x) iv y iv ); S96. Based on different perpendicular foot coordinate values ​​d iv (x) iv y iv The rotation angle R and translation distance t can be calculated using the following formula: In the formula, f(R,t) is a function of the rotation angle R and the translation distance t, where R is the rotation angle, t is the translation distance, and k is the plane Q. v The number of upper nearest neighbor pairs, x iv y iv These are the coordinates of the foot of the perpendicular; S97. Based on the rotation angle R and translation distance t, translate and rotate the spliced ​​point cloud data set B to obtain a new corresponding point cloud set B'; S98. Construct a plane Q from the points on the new corresponding point cloud set B'. A Calculate the distance D from the point to the plane by finding the perpendicular line. i According to each distance D i Calculate the average distance D between the new corresponding point cloud set B' and the target point set A. 平均 ; In the formula, D 平均 D is the average distance. i For a point to plane Q A The distance, where N is the number of points; S99, If D 平均 If the error is less than the set splicing error d', stop the iteration; otherwise, return to S95 until the termination condition D is met. 平均 Less than the set splicing error d'; S910. Update the stitched point cloud data to the target point cloud data A, update the reselected point cloud data to the stitched point cloud data B, and return to S91 to stitch the point cloud data of the H-beam until all image point cloud data are stitched together to obtain all the point cloud data of the H-beam. S911. Denoise all point cloud data of the spliced ​​H-beams, especially for the L-beams. X -R≤X i ≤L X +L+R,-W / 2-T≤Y i Point cloud data within the range of ≤W / 2+T are retained, while data outside this range are discarded. After discarding, complete point cloud data of the H-beam is obtained, where L X Let X be the initial position coordinates of the H-beam in the X direction. i Let x be the horizontal x-coordinate value of the point cloud data, and y be the horizontal x-coordinate value. i Let L be the horizontal y-coordinate value of the point cloud data, and L be the length of the H-beam. In the formula, R is the allowable reserve value in the length direction and T is the allowable reserve value in the width direction. The reserve value should be set in the computer according to the requirements.

8. The method for positioning and adjusting H-beam machine tool processing according to claim 1, characterized in that, S10 includes the following steps: S101, Set the point cloud data P for each H-beam. i Weighting coefficient ω i ; In the formula, For point cloud data weighting system, The coordinates of the point cloud data in the horizontal x-direction; S102. Constructing the least-squares linear fitting function for the H-beam profile: In the formula, Let a be the H-beam profile function, where a is the function slope, b is the intercept, n is the number of fitting points, and x is the x-axis. i y i These are the coordinates of the fitted points; S103. Calculate the a and b values ​​of the weighted least squares linear fitting algorithm function for the H-beam profile. S104. Repeat S102 and S103 to calculate the outline of the H-beam, which are marked as L1, L2, L3 and L4 respectively.

9. The method for positioning and adjusting H-beam machine tool processing according to claim 1, characterized in that, In S11, the Octree search algorithm is used for retrieval.

10. The method for positioning and adjusting H-beam machine tool processing according to claim 9, characterized in that, The retrieval radius using the Octree search algorithm is R = W / 2.

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