Automatic edge-searching plate laser cutting machine and edge-searching positioning method

Abstract

The application discloses an automatic edge-searching plate laser cutting machine and an edge-searching positioning method, and relates to the technical field of laser cutting machines. The automatic edge-searching plate laser cutting machine comprises a machine tool, mounting plates arranged on both sides of the machine tool, an X-axis moving module one arranged above the mounting plates, a Y-axis moving module one arranged on the X-axis moving module one, and a laser cutting head movably arranged below the Y-axis moving module one. The linear equation obtained by measuring multiple coordinate points of the edge of a metal plate and the linear equation obtained by an edge algorithm are fused through a laser sensor one and a laser sensor two, which is equivalent to double-checking the positioning of the edge of the metal plate. The results obtained by the two different technical approaches are mutually verified and supplemented, errors possibly caused by a single method can be effectively reduced, the accuracy of the linear equation is greatly improved, and the accuracy of determining the position of the edge of the plate is improved.

Description

Technical Field

[0001] This invention relates to the field of laser cutting technology, and more particularly to an automatic edge-finding laser cutting machine for sheet metal and an edge-finding and positioning method. Background Technology

[0002] Laser cutting machines with visual positioning capabilities are those equipped with a vision system. This system uses a camera to capture images, identify the shape, position, and orientation of the material, and then uses computer software for image processing and coordinate transformation to achieve precise positioning and cutting of the material. Visual positioning improves the processing efficiency and quality of laser cutting machines and is suitable for cutting irregularly shaped, complex patterns, and high-precision materials.

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

[0004] To address the shortcomings of existing technologies, this invention provides the following technical solution:

[0005] Automatic edge-finding laser cutting machine for sheet metal includes:

[0006] The machine tool has mounting plates on both sides;

[0007] X-axis moving module one is disposed above the mounting plate;

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

[0009] The second X-axis moving module is embedded in the side wall of the mounting plate. The second X-axis moving module is equipped with a movable laser sensor for sensing and identifying the position of the X-side of the metal plate placed on the machine tool.

[0010] Y-axis moving module two is set on the machine tool and perpendicular to the extension direction of the machine tool. The Y-axis moving module two is equipped with a moving laser sensor two for identifying the position of the Y side of the metal plate placed on the machine tool. The X side and the Y side are two adjacent sides of the metal plate.

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

[0012] An edge-finding and positioning method for an automatic edge-finding laser cutting machine for sheet metal, using the aforementioned automatic edge-finding laser cutting machine for sheet metal, is characterized by the following steps:

[0013] S10: Determine the coordinate system based on the 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. When the laser sensor 1 is blocked by the metal plate, it starts to record position information until the laser sensor 1 is no longer blocked by the metal plate and stops recording position information.

[0015] S30: The Y-axis moving module two drives the laser sensor two to move along the Y direction of the machine tool. When the laser sensor two is blocked by the metal plate, it starts to record position information until the laser sensor two is no longer blocked by the metal plate and stops recording position information.

[0016] S40: Based on the multiple sets of position information provided by laser sensor one and laser sensor two, the corresponding spatial straight line equations of the X side and Y side of the metal plate are obtained by fitting.

[0017] S50: Using an image acquisition device, the metal sheet is photographed. The edge points (x1, y1), (x2, y2), ..., (x...) on the X side are obtained 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: Based on the position information of the image acquisition device, the corresponding spatial straight line equations of the X side and Y side of the metal plate are obtained by fitting.

[0019] S60: Combine the spatial line equation corresponding to the X side in step S40 with the spatial line equation corresponding to the X side in step S50 using the fusion compensation formula to form a fused line equation;

[0020] S61: Combine the spatial line equation corresponding to the Y side in step S40 with the spatial line equation corresponding to the Y side in step S50 using the fusion compensation formula to form a fused line equation;

[0021] S70: Based on the intersection point P fitted in steps S60 and S61, drive the laser cutting head to move to the intersection point.

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

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

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

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

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

[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 multi-points, n is the number of multi-points, and y is the number of multi-points. k and x k These are the coordinates of the k-th data point;

[0034] m chuanx It is the slope of the equation of multiple points on the X-side of a metal plate detected by a laser sensor;

[0035] b chuanx The laser sensor detects the intercept of a multi-point equation on the X-side of a metal sheet.

[0036] m tuxiangx It is the slope of the multi-point equation of the X side of the metal plate after the image acquisition device has processed it;

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

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

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

[0040] Y-side of metal sheet:

[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] Where z and h are the number of points, y k and x k These are the coordinates of the k-th data point; m chuany It is the slope of the multi-point equation of the Y-side of the metal plate detected by the laser sensor; b chuany It is the intercept of the multi-point equation of the Y-side of the metal plate detected by the laser sensor; m tuxiangy It is the slope of the multi-point equation of the Y-side of the metal plate after image acquisition device processing; b tuxiangy It is the intercept of the multi-point equation of the Y-side of the metal plate after image acquisition device processing; m Fy It is the slope of the multi-point equation of the X-side of the fused metal sheet; b Fy It is the intercept of the multi-point equation of the X side of the fused metal sheet.

[0047] The beneficial effects of this invention are:

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

[0049] 2. When locating the edge of the metal sheet, the flatness of the metal sheet's side and the influence of its reflection are fully and comprehensively considered. This reduces the impact of the flatness and reflection on the edge location, ensuring the accuracy of the edge location and avoiding empty cuts during laser cutting. This allows the laser cutting body to consistently and stably cut the metal sheet, improving the stability and safety of the cutting process. It also allows for more efficient use of the metal sheet, increasing its utilization rate and reducing resource waste. Attached Figure Description

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

[0051] Figure 2 This is a top view of the machine tool of the present invention;

[0052] Reference 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 Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0054] Example 1

[0055] Automatic edge-finding laser cutting machine for sheet metal includes:

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

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

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

[0059] X-axis moving module 2 50 is embedded in the side wall of the mounting plate 11. The X-axis moving module 2 50 is equipped with a movable laser sensor 1 51 for sensing and identifying the position of the X side of the metal plate placed on the machine tool 10.

[0060] Y-axis moving module 2 60 is disposed on the machine tool 10 and perpendicular to the extension direction of the machine tool 10. The Y-axis moving module 2 60 is provided with a movable laser sensor 2 61 for identifying the position of the Y side of the metal plate placed on the machine tool 10. The X side and the Y side are two adjacent sides of the metal plate.

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

[0062] The metal sheet is placed on the machine tool 10, and then the image acquisition device 40, the X-axis moving module 2 50, and the Y-axis moving module 2 60 are started simultaneously. 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 drive the laser sensor 1 and the laser sensor 2 respectively 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 better drive the laser cutting head 30 to cut the metal sheet on the machine tool 10, and the driving method is more stable, ensuring the cutting quality. The image acquisition device is a CDD camera or a digital camera. Both CDD cameras and digital cameras are existing technologies, and their specific structures will not be described in detail here.

[0063] Example 2

[0064] When the surface of the metal sheet detected by the laser sensor is uneven, the distribution of coordinate points becomes more dispersed, and the dispersion increases significantly. This dispersion of data directly affects the result of line fitting, causing the fitted line equation to deviate significantly from the actual "ideal line". Furthermore, the reflection of the metal sheet, when captured in the image, makes some areas of the image very bright while other areas become very dark, resulting in reduced image contrast. Low-contrast images make edge detection more difficult because the gradient changes at the edges are not obvious. These erroneous edge points will interfere with the subsequent line detection and fitting process.

[0065] Edge-finding positioning method for automatic edge-finding laser cutting machine for sheet metal.

[0066] Based on the reference plane of machine tool 10, a coordinate system is determined; the X-axis moving module 2 50 drives laser sensor 1 51 to move along the X direction of machine tool 10. When laser sensor 1 51 is blocked by a metal plate, it begins to record position information until it stops recording position information when it is no longer blocked by the metal plate. The coordinates of the X-side position are A1(x1,y1), A2(x2,y2), ... A i (X i ,Y i Fit the equation of the straight line on the X side;

[0067]

[0068] Where n is the number of points, y i and x i These are the coordinates of the i-th data point;

[0069] The Y-axis moving module 60 drives the laser sensor 61 to move along the Y-axis of the machine tool. When the laser sensor 61 is blocked by the metal plate, it starts recording position information until it stops recording position information when the laser sensor 61 is no longer blocked by the metal plate. The coordinates of the Y-side position are B1(x1,y1), B2(x2,y2), ... B i (x z ,y z Fit the equation of the straight line on the Y side.

[0070]

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

[0072] Using an image acquisition device to photograph a metal sheet, a set of edge points (x1, y1), (x2, y2), ..., (x...) on the X side were obtained through the Canny edge detection algorithm and filtering steps. n ,y n Fit the equation of the straight line on the X side;

[0073]

[0074] Where n is the number of points, y n and x n These 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 equation of the straight line on the Y side;

[0076]

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

[0078] The spatial straight line equation corresponding to the X-side detected by the laser sensor is combined with the spatial straight line equation corresponding to the X-side detected by the image acquisition device using a fusion compensation formula to form a fused straight line equation, which is then 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 multi-points, n is the number of multi-points, and y is the number of multi-points. k and x k These are the coordinates of the k-th data point;

[0086] m chuanx It is the slope of the equation of multiple points on the X-side of a metal plate detected by a laser sensor;

[0087] b chuanx The laser sensor detects the intercept of a multi-point equation on the X-side of a metal sheet.

[0088] m tuxiangx It is the slope of the multi-point equation of the X side of the metal plate after the image acquisition device has processed it;

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

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

[0091] b Fx It 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 laser sensor 2 is combined with the spatial straight line equation corresponding to the Y side obtained by the image acquisition device using a fusion compensation formula to form a fused straight line equation, and then the straight line equation is refitted:

[0093] Y-side of metal sheet:

[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] Where z and h are the number of points, y k and x k These are the coordinates of the k-th data point;

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

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

[0102] m tuxiangy It is the slope of the multi-point equation of the Y side of the metal plate after the image acquisition device has processed it;

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

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

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

[0106] Based on the refitted x-side line Y = m Fx x+b Fx The line Y = m on the y-side 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 the X-axis linear module one and the Y-axis linear module two.

[0107] The intersection of the two sets of linear equations obtained by fitting and fusing them is the coordinate of the corner point of the sheet metal. This makes the determined point more reasonable and accurate. Using this point as the starting point, when the laser cutting head is adjusted to cut the metal sheet, it can make the maximum use of the metal sheet, reduce waste, ensure the stability and safety of the cutting, and improve the cutting efficiency.

[0108] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. An edge-finding and positioning method for an automatic edge-finding laser cutting machine for sheet metal, characterized in that, Automatic edge-finding laser cutting machine for sheet metal includes: Machine tool (10), wherein mounting plates (11) are provided on both sides of the machine tool (10); X-axis moving module 1 (20) is disposed above the mounting plate (11); Y-axis moving module 1 (21) is disposed on X-axis moving module 1 (20), and laser cutting head (30) is movably disposed below Y-axis moving module 1 (21); X-axis moving module two (50) is embedded in the side wall of the mounting plate (11). The X-axis moving module two (50) is equipped with a movable laser sensor one (51) for sensing and identifying the position of the X side of the metal plate parked on the machine tool (10). Y-axis moving module two (60) is set on the machine tool (10) and perpendicular to the extension direction of the machine tool (10). The Y-axis moving module two (60) is equipped with a moving laser sensor two (61) for identifying the position of the Y side of the metal plate placed on the machine tool (10). The X side and the Y side are two adjacent sides of the metal plate. An image acquisition device (40) is installed above the machine tool (10); Includes the following steps: S10: Determine the coordinate system based on the reference plane 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). When the laser sensor 1 (51) is blocked by the metal plate, it starts to record position information until the laser sensor 1 is no longer blocked by the metal plate and stops recording position information. S30: The Y-axis moving module two (60) drives the laser sensor two (61) to move along the Y direction of the machine tool (10). When the laser sensor two (61) is blocked by the metal plate, it starts to record position information until the laser sensor two is not blocked by the metal plate and stops recording position information. S40: Based on the multiple sets of position information provided by laser sensor one (51) and laser sensor two (61), the corresponding spatial straight line equations of the X side and Y side of the metal plate are obtained by fitting. S50: Using the image acquisition device (40), the metal plate is photographed, and the edge points (x1, y1), (x2, y2)...(x1, y1), on the X side are obtained through the Canny edge detection algorithm and filtering steps. n ,y n ), Y-side edge points (x1, y1), (x2, y2)...(x h ,yh); S51: Based on the position information of the image acquisition device, the corresponding spatial straight line equations of the X side and Y side of the metal plate are obtained by fitting. S60: Combine the spatial line equation corresponding to the X side in step S40 with the spatial line equation corresponding to the X side in step S50 using the fusion compensation formula to form a fused line equation; S61: Combine the spatial line equation corresponding to the Y side in step S40 with the spatial line equation corresponding to the Y side in step S50 using the fusion compensation formula to form a fused line equation; S70: Based on the fitting intersection point P in steps S60 and S61, drive the laser cutting head to move to the intersection point; In step S41, the equation of the spatial line on the X side is Y = m chuanx x+b chuanx ; The equation of the spatial line on the Y-side is Y = m chuany x+b chuany ; In step S50, the equation of the spatial line on the X side is Y = m tuxiangx x+b tuxiangx ; The equation of the spatial line on the Y-side is Y = m tuxaiangy x+b tuxiangy ; The calculation method of the fusion compensation formula in step S61 is as follows: 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 multi-points, n is the number of multi-points, and y is the number of multi-points. k and x k These are the coordinates of the k-th data point; m chuanx It is a laser sensor that detects the slope of the equation of multiple points on the X-side of a metal sheet; b chuanx The laser sensor detects the intercept of a multi-point equation on the X-side of a metal sheet; m tuxiangx It is the slope of the multi-point equation of the X-side of the metal plate after image acquisition device processing; b tuxiangx It is the intercept of the multi-point equation of the X-side of the metal plate after image acquisition device processing, in meters. Fx It is the slope of the multi-point equation of the X-side of the fused metal sheet; b Fx It is the intercept of the multi-point equation of the X side of the fused metal sheet; Y-side of metal sheet: m Fy =αm chuany +(1-α)m tuxiangy b Fy =αb chuany +(1-α)b tuxiangy Y=m Fy x+b Fy Where z and h are the number of points, y k and x k These are the coordinates of the k-th data point; m chuany It is the slope of the multi-point equation of the Y-side of the metal plate detected by the laser sensor; b chuany It is the intercept of the multi-point equation of the Y-side of the metal plate detected by the laser sensor; m tuxiangy It is the slope of the multi-point equation of the Y-side of the metal plate after image acquisition device processing; b tuxiangy It is the intercept of the multi-point equation of the Y-side of the metal plate after image acquisition device processing; m Fy It is the slope of the multi-point equation of the X-side of the fused metal sheet; b Fy It is the intercept of the multi-point equation of the X side of the fused metal sheet.

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