Automatic edge-searching laser cutting machine for plates and edge-searching positioning method

Abstract

The invention discloses an automatic edge-searching plate laser cutting machine and an edge-searching positioning method. The automatic edge-searching plate laser cutting machine comprises a machine tool, and mounting plates are arranged on the two sides of the machine tool; the X-axis moving module I is arranged above the mounting plate; the first Y-axis moving module is arranged on the first X-axis moving module, and a laser cutting head is movably arranged below the first Y-axis moving module; a linear equation obtained by measuring a plurality of coordinate points of the edge of the metal plate by the laser sensor I and the laser sensor II is fused with a linear equation obtained by an edge algorithm, equivalently, double verification is performed on positioning of the edge of the metal plate, and results obtained by two different technical approaches are mutually verified and complemented; errors possibly caused by a single method can be effectively reduced, the accuracy of a linear equation is greatly improved, and then the accuracy of determining the edge position of the plate is improved.

Description

Technical Field

[0001] The invention relates to the technical field of laser cutting, and in particular to an automatic edge-finding plate laser cutting machine and an edge-finding positioning method. Background Art

[0002] Laser cutting machines with visual positioning function refer to those equipped with a visual system. They can collect images through cameras, identify the shape, position and direction of the plate, and then perform image processing and coordinate conversion through computer software to achieve accurate positioning and cutting of the plate. The visual positioning function can improve the processing efficiency and quality of the laser cutting machine, and is suitable for cutting plates with irregular shapes, complex patterns and high precision requirements.

[0003] However, due to the reflection of metal sheets, the reflection will make some areas in the image very bright, while other areas will become very dark, resulting in reduced image contrast. Low-contrast images will make edge detection more difficult because the gradient change of the edge is not obvious. These erroneous edge points will interfere with the subsequent straight line detection and fitting process. Therefore, an automatic edge-finding sheet metal laser cutting machine and an edge-finding positioning method are proposed to solve this problem. Summary of the invention

[0004] The present invention aims at the deficiencies in the prior art and provides the following technical solutions:

[0005] Automatic edge-finding sheet metal laser cutting machine, including:

[0006] A machine tool, wherein mounting plates are provided on both sides of the machine tool;

[0007] An X-axis moving module 1 is arranged above the mounting plate;

[0008] A Y-axis moving module 1 is arranged on the X-axis moving module 1, and a laser cutting head is movably arranged below the Y-axis moving module 1;

[0009] An X-axis moving module 2 is embedded in the side wall of the mounting plate, and a moving laser sensor 1 is provided on the X-axis moving module 2 for sensing and identifying the position of the X side edge of the metal plate parked on the machine tool;

[0010] A second Y-axis moving module is arranged on the machine tool and perpendicular to the extension direction of the machine tool. A second moving laser sensor is arranged on the second Y-axis moving module for identifying the position of the Y side edge of the metal sheet parked on the machine tool, wherein the X side edge and the Y side edge are two adjacent sides of the metal sheet;

[0011] An image acquisition device is installed above the machine tool.

[0012] The edge-finding and positioning method of the automatic edge-finding plate laser cutting machine adopts the above-mentioned automatic edge-finding plate laser cutting machine, and is characterized in that it includes the following steps:

[0013] S10: Determine a coordinate system according to a reference surface of the machine tool;

[0014] S20: the X-axis moving module 2 drives the laser sensor 1 to move along the X direction of the machine tool, and when the laser sensor 1 is blocked by the metal sheet, it starts to record the position information, and stops recording the position information when the laser sensor 1 is not blocked by the metal sheet;

[0015] S30: the Y-axis moving module 2 drives the laser sensor 2 to move along the Y direction of the machine tool, and when the laser sensor 2 is blocked by the metal sheet, it starts to record the position information, and stops recording the position information when the laser sensor 2 is not blocked by the metal sheet;

[0016] S40: fitting the spatial straight line equations corresponding to the X side and the Y side of the metal plate according to the multiple sets of position information provided by the laser sensor 1 and the laser sensor 2;

[0017] S50: Use the image acquisition device to shoot the metal plate, and obtain the X side edge points (x1, y1), (x2, y2) through the Canny edge detection algorithm and filtering steps. n ,y n ), Y side edge points (x1,y1), (x2,y2).......(x h ,y h );

[0018] S51: fitting the spatial straight line equations corresponding to the X side and the Y side of the metal plate according to the position information of the image acquisition device;

[0019] S60: The spatial straight line equation corresponding to the X side in step S40 and the spatial straight line equation corresponding to the X side in step S50 are merged into a merged straight line equation through a fusion compensation formula;

[0020] S61: The spatial straight line equation corresponding to the Y side in step S40 and the spatial straight line equation corresponding to the Y side in step S50 are merged into a fused straight line equation through a fusion compensation formula;

[0021] S70: Fit the intersection point P according to steps S60 and S61, and drive the laser cutting head to move to the intersection point.

[0022] As an improvement of the above technical solution, in step S41, the spatial straight line equation of the X side is Y=m chuanx x+b chuanx ;

[0023] The equation of the spatial straight line on the Y side is Y = m chuany x+b chuany .

[0024] As an improvement of the above technical solution, in step S50, the spatial straight line equation of the X side is Y=m tuxiangx x+b tuxiangx ;

[0025] The equation of the spatial straight line on the Y side is Y = m tuxiangy x+b tuxiangy .

[0026] As an improvement of the above technical solution, the calculation method of the fusion compensation formula in step S61 is:

[0027] Metal sheet X side:

[0028]

[0029]

[0030] m Fx =αm chuanx +(1-α)m tuxiangx

[0031] b Fx =αb chuanx +(1-α)b tuxiangx

[0032] Y=m Fx x+b Fx

[0033] Where i is the number of multiple points, n is the number of multiple points, y k and x k is the coordinate of the kth data point;

[0034] m chuanx is the slope of the multi-point equation of the X side of the metal sheet detected by the laser sensor;

[0035] b chuanx It is the intercept of the multi-point equation when the laser sensor detects the X side of the metal sheet;

[0036] m tuxiangx is the slope of the multi-point equation of the X side of the metal sheet after processing by the image acquisition device;

[0037] b tuxiangx is the intercept of the multi-point equation of the X side of the metal sheet after processing by the image acquisition device;

[0038] m Fx is the slope of the multi-point equation of the X side of the fused metal sheet;

[0039] b Fx is the intercept of the multi-point equation of the X side of the fused metal sheet;

[0040] Metal sheet Y side:

[0041]

[0042]

[0043] m Fy =αm chuany +(1-α)m tuxiangy

[0044] b Fy =αb chuany +(1-α)b tuxiangy

[0045] Y=m Fy x+b Fy .

[0046] Among them, z and h are the number of multiple points, y k and x k is the coordinate of the kth data point; m chuany is the slope of the multi-point equation of the Y side of the metal plate detected by the laser sensor 2; b chuany is the intercept of the multi-point equation of the Y side of the metal plate detected by the laser sensor 2; m tuxiangy is the slope of the multi-point equation of the Y side of the metal sheet after processing by the image acquisition device; b tuxiangy is the intercept of the multi-point equation of the Y side of the metal sheet after processing by the image acquisition device; m Fy is the slope of the multi-point equation of the X side of the fused metal sheet; b Fy is the intercept of the multi-point equation of the X side of the fused metal sheet.

[0047] Beneficial effects of the present invention:

[0048] 1. Laser sensor 1 and laser sensor 2 combine the linear equations obtained by measuring multiple coordinate points on the edge of the metal sheet with the linear equations obtained by the edge algorithm, which is equivalent to double-checking the positioning of the edge of the metal sheet. The results obtained by the two different technical approaches verify and complement each other, which can effectively reduce the errors that may occur in a single method, greatly improve the accuracy of the linear equation, and thus improve the accuracy of determining the edge position of the sheet;

[0049] 2. When edge-finding and positioning the metal sheet, the flatness of the side of the metal sheet and the reflective effect of the metal sheet are fully and comprehensively considered, reducing the impact of the flatness of the side of the metal sheet and the reflection on edge-finding and positioning, ensuring the accuracy of edge-finding and positioning, avoiding empty cutting during the laser cutting process, so that the laser cutting body can always stably cut the metal sheet, improve the stability and safety of cutting, and make more full use of the metal sheet, thereby improving the utilization rate of the metal sheet and reducing the waste of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is the front view of the overall structure of the present invention;

[0051] Figure 2 A top view of the machine tool of the present invention;

[0052] Figure numerals: 10, machine tool; 20, X-axis moving module one; 21, Y-axis moving module one; 30, laser cutting head; 40, image acquisition device; 50, X-axis moving module two; 51, laser sensor one; 60, Y-axis moving module two; 61, laser sensor two. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0054] Embodiment 1

[0055] Automatic edge-finding sheet metal laser cutting machine, including:

[0056] A machine tool 10, wherein mounting plates 11 are provided on both sides of the machine tool 10;

[0057] An X-axis moving module 20 is disposed above the mounting plate 11;

[0058] A Y-axis moving module 21 is disposed on the X-axis moving module 20, and a laser cutting head 30 is movably disposed below the Y-axis moving module 21;

[0059] The second X-axis moving module 50 is embedded in the side wall of the mounting plate 11, and the second X-axis moving module 50 is provided with a movable laser sensor 51 for sensing and identifying the position of the X side of the metal plate parked on the machine tool 10;

[0060] The second Y-axis moving module 60 is arranged on the machine tool 10 and is perpendicular to the extension direction of the machine tool 10. The second Y-axis moving module 60 is provided with a second moving laser sensor 61 for identifying the position of the Y side edge of the metal sheet parked on the machine tool 10. The X side edge and the Y side edge are two adjacent sides of the metal sheet;

[0061] The image acquisition device 40 is installed above the machine tool 10 .

[0062] Place the metal sheet on the machine tool 10, and then start the image acquisition device 40, the X-axis moving module 2 50 and the Y-axis moving module 2 60 at the same time. The image acquisition device 40 acquires the image of the sheet, and the X-axis moving module 2 50 and the Y-axis moving module 2 60 respectively drive the laser sensor 1 and the laser sensor 2 to acquire the edge position information of the metal sheet. The X-axis moving module 1 20 and the Y-axis moving module 1 21 can be used to better drive the laser cutting head 30 to cut the metal sheet on the machine tool 10, and the driving method is more stable, thereby ensuring the cutting quality. The image acquisition device is a CDD camera or a digital camera. Both the CDD camera and the digital camera are prior art, and the specific structure will not be repeated here.

[0063] Embodiment 2

[0064] When the surface of the metal sheet detected by the laser sensor is uneven, the coordinate points are more dispersed and the discreteness increases significantly. The discreteness of this data will directly affect the result of the straight line fitting, making the fitted straight line equation deviate greatly from the actual "ideal straight line". The reflection of the metal sheet, through the captured image, will make some areas in the image very bright and other areas very dark, resulting in reduced image contrast. Low-contrast images will make edge detection more difficult because the gradient change of the edge is not obvious. These erroneous edge points will interfere with the subsequent straight line detection and fitting process;

[0065] Edge-finding and positioning method of automatic edge-finding plate laser cutting machine.

[0066] According to the reference surface of the machine tool 10, the coordinate system is determined; the X-axis moving module 2 50 drives the laser sensor 1 51 to move along the X direction of the machine tool 10, and when the laser sensor 1 51 is blocked by the metal sheet, it starts to record the position information, and stops recording the position information when the laser sensor 1 is not blocked by the metal sheet. The coordinates of the X side position are A1 (x1, y1), A2 (x2, y2).......A i (X i ,Y i ), fit the straight line equation of the X side;

[0067]

[0068] Where n is the number of multiple points, y i and x i is the coordinate of the ith data point;

[0069] The Y-axis moving module 2 60 drives the laser sensor 2 61 to move along the Y direction of the machine tool 10. When the laser sensor 2 61 is blocked by the metal sheet, it starts to record the position information until the laser sensor 2 stops recording the position information when it is not blocked by the metal sheet. The coordinates of the Y side position are B1 (x1, y1), B2 (x2, y2).......B i (x z ,y z ), fit the straight line equation of the Y side

[0070]

[0071] Where n is the number of multiple points, y z and x z are the coordinates of the zth data point;

[0072] The metal sheet is photographed by an image acquisition device, and a set of edge points (x1, y1), (x2, y2) on the X side are obtained through the Canny edge detection algorithm and filtering steps. n ,y n ), fit the straight line equation of the X side;

[0073]

[0074] Where n is the number of multiple points, y n and x n are the coordinates of the nth data point;

[0075] A set of edge points on the Y side (x1, y1), (x2, y2).......(x h ,y h ), fit the straight line equation of the Y side;

[0076]

[0077] Where n is the number of multiple points, y h and x h are the coordinates of the hth data point;

[0078] The spatial straight line equation corresponding to the X side detected by the laser sensor 1 and the spatial straight line equation corresponding to the X side detected by the image acquisition device are fused through the compensation formula to form a fused straight line equation, and the straight line equation is refitted:

[0079] Metal sheet X side:

[0080]

[0081]

[0082] m Fx =αm chuanx +(1-α)m tuxiangx

[0083] b Fx =αb chuanx +(1-α)b tuxiangx

[0084] Y=m Fx x+b Fx

[0085] Where i is the number of multiple points, n is the number of multiple points, y k and x k is the coordinate of the kth data point;

[0086] m chuanx is the slope of the multi-point equation of the X side of the metal sheet detected by the laser sensor;

[0087] b chuanx It is the intercept of the multi-point equation when the laser sensor detects the X side of the metal sheet;

[0088] m tuxiangx is the slope of the multi-point equation of the X side of the metal sheet after processing by the image acquisition device;

[0089] b tuxiangx is the intercept of the multi-point equation of the X side of the metal sheet after processing by the image acquisition device;

[0090] m Fx is the slope of the multi-point equation of the X side of the fused metal sheet;

[0091] b Fx is the intercept of the multi-point equation of the X side of the fused metal sheet;

[0092] The spatial straight line equation corresponding to the Y side detected by the second laser sensor and the spatial straight line equation corresponding to the Y side detected by the image acquisition device are fused through the compensation formula to form a fused straight line equation, and the straight line equation is refitted:

[0093] Metal sheet Y side:

[0094]

[0095]

[0096] m Fy =αm chuany+(1-α)m tuxiangy

[0097] b Fy =αb chuany +(1-α)b tuxiangy

[0098] Y=m Fy x+b Fy .

[0099] Among them, z and h are the number of multiple points, y k and x k is the coordinate of the kth data point;

[0100] m chuany is the slope of the multi-point equation of the Y side of the metal sheet detected by the laser sensor 2;

[0101] b chuany is the intercept of the multi-point equation of the Y side of the metal sheet detected by the laser sensor 2;

[0102] m tuxiangy is the slope of the multi-point equation of the Y side of the metal sheet after processing by the image acquisition device;

[0103] b tuxiangy is the intercept of the multi-point equation of the Y side of the metal sheet after processing by the image acquisition device;

[0104] m Fy is the slope of the multi-point equation of the X side of the fused metal sheet;

[0105] b Fy is the intercept of the multi-point equation of the X side of the fused metal sheet.

[0106] According to the refitted x-side straight line Y=m Fx x+b Fx The straight line with the y side Y=m Fy x+b Fy , the intersection point p(xp,yp) is calculated by fitting, and the laser cutting head is moved to p(xp,yp) using X-axis linear module 1 and Y-axis linear module 2.

[0107] The intersection of the two sets of linear equations that are fitted and fused is the coordinate of the corner point of the plate. In this way, the determined point position is more reasonable and accurate. Taking this point position as the starting point, the laser cutting head is controlled to cut the metal plate after adjustment, which can maximize the use of the metal plate, reduce the waste of metal plates, ensure the stability and safety of cutting, and improve cutting efficiency.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

Claims

1. Automatic edge-finding plate laser cutting machine, characterized by: include: A machine tool (10), wherein mounting plates (11) are provided on both sides of the machine tool (10); An X-axis moving module (20) is disposed above the mounting plate (11); A Y-axis moving module (21) is disposed on the X-axis moving module (20), and a laser cutting head (30) is movably disposed below the Y-axis moving module (21); X-axis moving module 2 (50) is embedded in the side wall of the mounting plate (11), and a movable laser sensor 1 (51) is arranged on the X-axis moving module 2 (50) for sensing and identifying the position of the X side edge of the metal plate parked on the machine tool (10); A second Y-axis moving module (60) is arranged on the machine tool (10) and is perpendicular to the extension direction of the machine tool (10). A second moving laser sensor (61) is arranged on the second Y-axis moving module (60) for identifying the position of the Y side edge of the metal sheet parked on the machine tool (10), wherein the X side edge and the Y side edge are two adjacent sides of the metal sheet; An image acquisition device (40) is installed above the machine tool (10).

2. An edge-finding and positioning method for an automatic edge-finding plate laser cutting machine, using the automatic edge-finding plate laser cutting machine of claim 1, characterized in that: The following steps are involved: S10: determining a coordinate system according to a reference surface of the machine tool (10); S20: the X-axis moving module 2 (50) drives the laser sensor 1 (51) to move along the X direction of the machine tool (10), and when the laser sensor 1 (51) is blocked by the metal plate, it starts to record the position information, and stops recording the position information when the laser sensor 1 is no longer blocked by the metal plate; S30: the Y-axis moving module 2 (60) drives the laser sensor 2 (61) to move along the Y direction of the machine tool (10), and when the laser sensor 2 (61) is blocked by the metal plate, it starts to record the position information, and stops recording the position information when the laser sensor 2 is no longer blocked by the metal plate; S40: fitting the spatial straight line equations corresponding to the X side and the Y side of the metal plate according to the multiple sets of position information provided by the laser sensor 1 (51) and the laser sensor 2 (61); S50: Using the image acquisition device (40) to photograph the metal plate, the X side edge points (x1, y1), (x2, y2) ... (x n ,y n ), Y side edge points (x1, y1), (x2, y2)......(x h ,y h ); S51: fitting the spatial straight line equations corresponding to the X side and the Y side of the metal plate according to the position information of the image acquisition device; S60: The spatial straight line equation corresponding to the X side in step S40 and the spatial straight line equation corresponding to the X side in step S50 are merged into a merged straight line equation through a fusion compensation formula; S61: The spatial straight line equation corresponding to the Y side in step S40 and the spatial straight line equation corresponding to the Y side in step S50 are merged into a fused straight line equation through a fusion compensation formula; S70: Fit the intersection point P according to steps S60 and S61, and drive the laser cutting head to move to the intersection point.

3. The edge-finding and positioning method of the automatic edge-finding plate laser cutting machine according to claim 2 is characterized in that: In step S41, the spatial straight line equation of the X side is Y=m chuanx x+b chuanx ; The equation of the spatial straight line on the Y side is Y = m chuany x+b chuany .

4. The edge-finding and positioning method of the automatic edge-finding plate laser cutting machine according to claim 3 is characterized in that: In step S50, the spatial straight line equation of the X side is Y=m tuxiangx x+b tuxiangx ; The equation of the spatial straight line on the Y side is Y = m tuxiangy x+b tuxiangy .

5. The edge-finding and positioning method of the automatic edge-finding plate laser cutting machine according to claim 4 is characterized in that: The calculation method of the fusion compensation formula in step S61 is: Metal sheet X side: m Fx =αm chuanx +(1-α)m tuxiangx b Fx =αb chuanx +(1-α)b tuxiangx Y=m Fx x+b Fx Where i is the number of multiple points, n is the number of multiple points, and y k and x k is the coordinate of the kth data point; m chuanx is the slope of the multi-point equation of the X side of the metal sheet detected by the laser sensor; b chuanx is the intercept of the multi-point equation when the laser sensor detects the metal sheet X side; m tuxiangx is the slope of the multi-point equation of the side X of the metal sheet after processing by the image acquisition device; b tuxiangx is the intercept of the multi-point equation of the X side of the metal sheet after processing by the image acquisition device, m Fx is the slope of the multi-point equation of the X side of the fused metal sheet; b Fx is the intercept of the multi-point equation of the X side of the fused metal sheet; Metal sheet Y side: m Fy =αm chuany +(1-α)m tuxiangy b Fy =αb chuany +(1-α)b tuxiangy Y=m Fy x+b Fy 。 Among them, z, h are the number of multiple points, y k and x k is the coordinate of the kth data point; m chuany is the slope of the multi-point equation of the Y side of the metal plate detected by the laser sensor 2; b chuany is the intercept of the multi-point equation of the Y side of the metal plate detected by the laser sensor 2; m tuxiangy is the slope of the multi-point equation of the Y side of the metal sheet after processing by the image acquisition device; b tuxiangy is the intercept of the multi-point equation of the Y side of the metal sheet after processing by the image acquisition device; m Fy is the slope of the multi-point equation of the X side of the fused metal sheet; b Fy is the intercept of the multi-point equation of the X side of the fused metal sheet.

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