Laser Detection-Based Method and Equipment for Detecting the Straightness of Copper Rod Casting

Abstract

The present invention relates to the technical field of detection equipment, and particularly to a method and equipment for detecting the straightness of a copper rod billet based on laser detection. The method includes: S10: Obtain a copper rod billet with a length of L; S20: Make the copper rod billet move at a uniform linear speed of V; S30: Set a point laser, set a receiver to receive the point laser, and calculate the placement angle of the copper rod billet based on the time when the point laser is blocked; S40: Set a line laser, and form an angle between the irradiation direction of the line laser and the movement direction of the copper rod billet. Set a camera to capture a top view image at the position of the line laser, display the top view contour of the copper rod billet through the line laser, and obtain the shape of the top view contour of the copper rod billet; S50: Calculate the top view center line of the copper rod billet, and then calculate the distances between the points on the two long sides of the top view contour shape of the copper rod billet and the top view center line, so as to determine whether the straightness of the copper rod billet is qualified. The present invention can effectively improve the detection efficiency of the straightness of the copper rod billet.

Description

Technical Field

[0001] The present invention relates to the technical field of detection equipment, and particularly relates to a method and equipment for detecting the straightness of a copper rod blank based on laser detection. Background Art

[0002] In the production process of copper rods, copper materials are first melted and then made into cylindrical blanks, and then the copper rod blanks are made into the required copper rod shapes through a drawing process. During the drawing process, the copper rod blank needs to have good straightness so as to ensure uniform stress in all directions of the drawing die and ensure the quality of the drawn copper rod products.

[0003] In the existing straightness detection technology, a dial indicator is usually moved along the generatrix of the copper rod blank, and the straightness of the copper rod blank is obtained by observing the change in the reading of the dial indicator. During detection, personnel need to accurately install the copper rod blank and the dial indicator, and the detection efficiency is very low. Therefore, a more efficient detection method or equipment is needed. Summary of the Invention

[0004] The present invention provides a method and equipment for detecting the straightness of a copper rod blank based on laser detection, which can effectively solve the problems in the background art.

[0005] A method for detecting the straightness of a copper rod blank based on laser detection provided by the present invention includes the following steps:

[0006] S10: Obtain a copper rod blank with a length of L;

[0007] S20: Make the copper rod blank move at a constant speed of V in a straight line;

[0008] S30: Set a point laser that irradiates along the horizontal direction and is perpendicular to the movement direction of the copper rod blank. The point laser is aligned with the center of the copper rod blank in height. Set a receiver to receive the point laser, and calculate the placement angle of the copper rod blank through the time when the point laser is blocked;

[0009] S40: Set a line laser that irradiates the movement path of the copper rod blank, and an included angle is formed between the irradiation direction of the line laser and the movement direction of the copper rod blank. Set a camera to capture a top view image at the position of the line laser, display the top view contour of the copper rod blank through the line laser, and obtain the shape of the top view contour of the copper rod blank;

[0010] S50: Calculate the top view center line of the copper rod blank according to the placement angle and the shape of the top view contour, then calculate the distances between the points on the two long sides of the top view contour shape of the copper rod blank and the top view center line, find the difference between the maximum distance and the minimum distance, and determine whether the difference exceeds a set threshold. If it exceeds, the copper rod blank is determined to be unqualified in straightness.

[0011] Further, in step S30, the specific process of calculating the placement angle of the copper rod billet is as follows:

[0012] When the point laser is blocked, start timing from 0, record the total blocked time as T, the diameter of the copper rod billet as D, and the placement angle of the copper rod billet as θ;

[0013] Let V·T = L·cosθ + D·sinθ;

[0014] Solve to obtain the value of the placement angle θ of the copper rod billet.

[0015] Further, in step S30, set multiple point lasers and multiple receivers. Each point laser calculates the value of the placement angle of the copper rod billet once, and finally take the average of all calculated placement angle values as the final placement angle θ.

[0016] Further, in step S30, it also includes a verification step, specifically:

[0017] When any point laser is blocked, start timing from 0. If the adjacent point laser of this point laser is blocked within the set time T1, then continue to execute the subsequent steps; if not, then determine whether this point laser is still blocked within the set time T1. If so, issue an alarm and stop the detection; if not, clear the data recorded this time.

[0018] Further, in step S40, the specific steps to obtain the top - view contour shape of the copper rod billet are as follows:

[0019] When the point laser is blocked, start timing from 0 and continuously record the time t;

[0020] Set the recognition range, which is located between the projection of the point laser and the line laser on the moving path of the copper rod billet;

[0021] When the copper rod billet enters the recognition range, the line laser will irradiate the copper rod billet to form a laser curve. The camera takes a top - view image and recognizes the laser curve in the top - view image. Take the positions of both ends of the laser curve in the direction perpendicular to the moving straight line of the copper rod billet as f1 and f2 respectively;

[0022] As the copper rod billet moves, when t takes different values, there will be corresponding f1 and f2, thus forming two functions F1 and F2 with time t as the independent variable and f1 and f2 as the dependent variables respectively;

[0023] Draw the images of F1 and F2 in the same coordinate system to obtain the top - view contour shape.

[0024] Further, after the camera takes the image, perform binarization processing on the image to form the final top - view image.

[0025] Further, in step S50, the specific process of calculating the top-down center line is as follows:

[0026] Take the point on the F1 image that is farthest from the F2 image as (t1_base, f1_base), and take the point on the F2 image that is farthest from the F1 image as (t2_base, f2_base);

[0027] Calculate the coefficient k. If t1_base - t2_base < 0, then k is taken as -1; if t1_base - t2_base > 0, then k is taken as 1;

[0028] Calculate the line with k·tanθ as the slope and passing through the point (t1_base / 2 + t2_base / 2, f1_base / 2 + f2_base / 2). This line is the top-down center line.

[0029] Further, in step S50, the recognition steps for the two long sides in the top-down contour shape are as follows:

[0030] If t1_base - t2_base < 0, then the part on F1 with an abscissa greater than t1_base is one long side, and the part on F2 with an abscissa less than t2_base is the other long side;

[0031] If t1_base - t2_base > 0, then the part on F1 with an abscissa less than t1_base is one long side, and the part on F2 with an abscissa greater than t2_base is the other long side.

[0032] The present invention also provides a copper rod blank straightness detection device based on laser detection, which is applicable to the above-mentioned copper rod blank straightness detection method based on laser detection, and includes:

[0033] A cutting module for cutting the copper rod blank;

[0034] A conveyor belt for driving the movement of the copper rod blank;

[0035] A point laser emitter, which is arranged on the conveyor belt and whose irradiation direction is perpendicular to the conveyor belt;

[0036] A receiver, which is arranged on the conveyor belt and is used to receive the point laser;

[0037] A line laser emitter, which is arranged above the conveyor belt and is used to irradiate the conveyor belt with line laser;

[0038] A camera, which is arranged above the conveyor belt and is used to obtain a top-down image;

[0039] A calculation module for obtaining the data of the receiver and the camera and calculating the straightness of the copper rod blank.

[0040] Furthermore, it also includes a covering hood, and the dot laser emitter, the receiver, the line laser emitter and the camera are all arranged inside the covering hood.

[0041] Through the technical solution of the present invention, the following technical effects can be achieved:

[0042] Through the cooperation of the dot laser and the line laser, this method can automatically identify the placement angle and contour of the copper rod billet, so as to calculate the straightness of the copper rod billet. During the detection process, the operator only needs to place the copper rod billet on the conveyor belt, thus effectively eliminating the installation and debugging steps in the traditional detection method, and greatly improving the detection efficiency. At the same time, this method can also realize the full-automatic detection throughout the process, reduce the operator intervention, and avoid the errors caused by the operator's operation problems, thereby effectively improving the detection accuracy. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0044] Figure 1 It is a schematic structural diagram of the copper rod billet straightness detection device based on laser detection in the present invention;

[0045] Figure 2 In the present invention Figure 1 Enlarged view of part Ⅰ;

[0046] Figure 3 It is a top view of the dot laser emitter in the present invention;

[0047] Figure 4 It is a top view of the present invention when the copper rod billet has not passed through the line laser emitter;

[0048] Figure 5 It is a top view of the present invention when the copper rod billet just starts to pass through the line laser emitter;

[0049] Figure 6 It is a top view of the present invention when the copper rod billet partially passes through the line laser emitter;

[0050] Figure 7 It is the top view contour shape of the copper rod billet in the present invention;

[0051] Figure 8 It is the top view contour shape of another form of the copper rod billet in the present invention;

[0052] Reference numerals: 1, conveyor belt; 2, dot laser emitter; 3, receiver; 4, line laser emitter; 5, camera. Detailed implementation manners

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0054] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0055] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0056] The present invention relates to a method for detecting the straightness of a copper rod billet based on laser detection. The specific steps include:

[0057] S10: Obtain a copper rod billet with a length of L as a sample to be detected. When obtaining it, according to the actual processing requirements, if it is a continuous casting condition, cut a section with a length of L from the long billet as the detection sample; if it is directly a segmented copper rod billet, take out several copper rod billets, cut off the excess part as appropriate, and process its length to L.

[0058] S20: Place the copper rod billet to be detected on the conveyor belt 1, and make the copper rod billet move in a uniform straight line at a speed of V.

[0059] S30: Set the dot laser emitter 2 to emit dot laser. The dot laser irradiates along the horizontal direction and is perpendicular to the moving direction of the copper rod billet. The dot laser is aligned with the center of the copper rod billet in height. Set the receiver 3 to receive the dot laser. When the copper rod billet passes between the dot laser emitter 2 and the receiver 3, the dot laser will be blocked by the copper rod billet, resulting in the receiver 3 being unable to receive the dot laser signal; calculate the placement angle of the copper rod billet relative to its moving straight line through the time when the dot laser is blocked.

[0060] S40: Set the line laser emitter 4 to emit a line laser. The line laser is directed towards the movement path of the copper rod blank. The line laser forms a line segment perpendicular to the movement direction of the copper rod blank on the conveyor belt 1, and an angle is formed between the irradiation direction of the line laser and the movement direction of the copper rod blank. Set the camera 5 to capture the top-down image at the position of the line laser. When the copper rod blank passes through the line laser, part of the line laser will be blocked by the copper rod blank, thus forming a curve on the copper rod blank. In this way, the top-down contour of the copper rod blank can be displayed through the line laser, and the top-down contour shape of the copper rod blank can be obtained.

[0061] S50: Calculate the top-down center line of the copper rod blank according to the placement angle and the top-down contour shape. Then calculate the distances between the points on the two long sides of the top-down contour shape of the copper rod blank and the top-down center line, find the difference between the maximum distance and the minimum distance, and determine whether the difference exceeds the set threshold. If it exceeds, the copper rod blank is judged to be unqualified in straightness.

[0062] Through the cooperation of the point laser and the line laser, this method can automatically identify the placement angle and contour of the copper rod blank, so as to calculate the straightness of the copper rod blank. During the detection process, personnel only need to place the copper rod blank on the conveyor belt 1. When placing, there is no need to specifically control the placement angle of the copper rod blank, thus effectively eliminating the installation and debugging steps in the traditional detection method and greatly improving the detection efficiency. At the same time, this method can also realize the full-automatic detection throughout the process, reduce the operation intervention of personnel, and avoid errors caused by personnel operation problems, thus effectively improving the detection accuracy. When placing the copper rod blank, since there is no other object to restrict the copper rod blank, under the action of gravity, the copper rod blank will rotate to the position where the worst straightness observation surface faces upward. And when this method detects, it takes the top-down view image of the copper rod blank, so the maximum straightness error of the copper rod blank can be detected.

[0063] Preferably, in step S30, the specific process and principle of calculating the placement angle of the copper rod blank are as follows:

[0064] Denote the diameter of the copper rod blank as D, and the placement angle of the copper rod blank relative to its movement straight line as θ;

[0065] As the placement angle of the copper rod blank is different, its projected length in the movement direction will be different, and there will be a specific relationship between this projected length and the placement angle of the copper rod blank, that is, the projected length H = L·cosθ + D·sinθ;

[0066] When the copper rod blank drawing moves to the point laser, it will block the point laser so that the receiver 3 cannot receive the laser signal. Once it is recognized that the point laser is blocked, the timing starts from 0 immediately; after the entire copper rod blank drawing passes through the point laser, the receiver 3 can receive the laser signal again. At this time, the total time T during which the point laser is blocked can be recorded;

[0067] Then within the time T, the length of the object passing through the point laser is V·T, and this length is the projected length H of the copper rod blank drawing in the moving direction. So we have:

[0068] V·T = L·cosθ + D·sinθ;

[0069] By solving, the value of the placement angle θ of the copper rod blank drawing can be obtained.

[0070] If only a single calculation is performed, it is easy to be interfered during the calculation process, resulting in inaccurate calculation results. Therefore, preferably, in step S30, as Figure 3 shown, multiple point lasers and multiple receivers 3 are set. The multiple point lasers and multiple receivers 3 correspond one by one and are distributed along the moving direction of the copper rod blank drawing; the placement angle value of the copper rod blank drawing is calculated for each point laser once, and finally the average of all the calculated placement angle values is used as the final placement angle θ; if necessary, a data verification step can also be set, specifically: after calculating multiple placement angle values, calculate the variance of these values. If the variance is less than the set threshold, it means that the data fluctuation is within the acceptable range; if the variance is greater than the set threshold, it means that individual data is very likely to be interfered during detection, and the interfered data (such as data that is significantly too large or too small) needs to be excluded, and the average of the remaining values is used as the final placement angle θ.

[0071] During use, it is also necessary to consider whether there will be unexpected vibrations or interferences, resulting in the point laser being accidentally blocked or the point laser being damaged and unable to work anymore. Therefore, in step S30 of this method, a verification step is also included, specifically:

[0072] When any point laser is blocked (i.e., when the receiver 3 cannot receive the laser signal), start timing from 0. If the adjacent point laser of this point laser is blocked within the set time T1, then it is very likely that a copper rod billet is passing by normally, causing each point laser to be blocked in sequence, and subsequent steps can be continued; if the adjacent point laser of this point laser is not blocked, then it is impossible for a copper rod billet to pass by. At this time, it is necessary to further determine whether this point laser is still blocked within the set time T1. If so, it is very likely that the point laser emitter 2 of this point laser is damaged, or a foreign object has fallen in front of the point laser emitter 2 or the receiver 3, resulting in abnormal operation, and an alarm is issued and the detection is stopped; if not, it means that although a foreign object has briefly affected the operation of the point laser, it no longer affects it at this time. Then the data recorded this time can be cleared for normal work. At this time, a certain warning message can be issued to prompt that there may be foreign object interference in the working environment, but the detection operation does not need to be completely stopped.

[0073] Preferably, in step S40, the specific steps and principles for obtaining the top view contour shape of the copper rod billet are as follows:

[0074] When the copper rod billet has not reached the line laser, as Figure 4 shown, the line laser will shine on the conveyor belt 1 to form a line segment a perpendicular to the conveyor belt 1;

[0075] When the copper rod billet reaches the line laser, as Figures 5 - 6 shown, since the surface of the copper rod billet is cylindrical, the line laser shining on the copper rod billet will become a curve in the form of line segment c. The two ends of line segment c will be aligned in the direction perpendicular to the movement direction of the copper tube billet, and the other line lasers that do not shine on the copper rod billet will shine on the conveyor belt 1 as straight line segments b and d as before; and since the copper rod billet is higher than the surface of the conveyor belt 1, from the top view perspective, there will also be a certain distance between line segment c and line segments b and d;

[0076] Based on the above imaging principle, the camera 5 can be used to capture the top view image and process it to form the top view contour shape of the copper rod billet.

[0077] When the point laser is blocked, start timing from 0 and continuously record the time t as a reference. When there are multiple point lasers, any one of the point lasers can be used as a reference;

[0078] Set the recognition range z, as Figures 4 - 6As shown, the recognition range z is located between the projections of the point laser and the line laser on the copper rod casting motion path (i.e., the line segment a formed by the line laser on the conveyor belt 1). At this position, the line segment c can be captured just right, while the line segments b and d are eliminated, so that the required line segment c can be accurately screened out.

[0079] When the copper rod blank enters the recognition range, the line laser will irradiate the copper rod blank to form a laser curve (i.e., line segment c), and the camera 5 will take a top-view image and recognize the laser curve in the top-view image. The camera 5 has its own coordinate system, and when taking pictures, it will assign coordinates to each pixel in the image to calculate the position of each pixel. During installation, it is necessary to pay attention to the alignment of the coordinate system of the camera 5, so that the extension direction of its horizontal coordinate is aligned with the opposite direction of the movement direction of the conveyor belt 1, and the vertical coordinate is perpendicular to the movement direction of the conveyor belt 1.

[0080] When the camera 5 captures the laser curve (i.e., line segment c), the positions of the two ends of the laser curve in the direction perpendicular to the straight line of the copper rod casting motion (i.e., the opposite of the vertical coordinate of the camera 5) are f1 and f2 respectively. The f1 and f2 can directly take the longitudinal distance values ​​corresponding to the coordinates of the two ends of the laser curve captured by the camera 5. For example: assuming that in the image captured by the camera 5, the coordinates of the two end points of the laser curve are (x, y1) and (x, y2) respectively, which means that the lateral distance of the two end points from the origin of the camera 5 in the image is x, and the longitudinal distances are y1 and y2 respectively. The actual distance corresponding to each pixel is P, then the actual longitudinal distances of the two end points from the origin of the camera 5 are y1·P=f1 and y2·P=f2 respectively. Since the subsequent calculations are all about the relationship between relative positions, the position of the camera 5 can be anywhere and will not affect the subsequent calculations.

[0081] As the copper rod moves, for example, Figure 5 Move to Figure 6 Position, as the moving time t of the copper rod billet drawing will increase, when t takes different values, there will be corresponding f1 and f2, thus forming two functions F1 and F2 with time t as the independent variable and f1 and f2 as the dependent variables respectively.

[0082] By drawing the F1 and F2 images on the same coordinate system, we can get the top view contour shape, such as Figures 7 - 8 shown.

[0083] In order to more clearly distinguish the two end points of the laser curve, the image can be binarized after the camera 5 takes the image. The overall color of the laser curve is brighter. Therefore, after the image is binarized, the laser curve part can be quickly extracted from the image, thereby forming a final overhead image with the laser curve part being white and the other parts being black.

[0084] Preferably, in step S50, the specific process and principle of calculating the top-down center line are as follows:

[0085] As Figures 7 - 8 shown, in the process of obtaining F1 and F2, since the areas of the incoming line laser and the outgoing line laser are very small (corresponding to points A and B on the figure), the accuracy at these two places is poor. Therefore, when calculating, mainly take the point on the F1 image that is farthest from the F2 image as C(t1_base, f1_base), and take the point on the F2 image that is farthest from the F1 image as D(t2_base, f2_base). These two points are the two determined corner points on the top-down image of the copper rod billet drawing. Through these two points, the coordinates of the center point O of the top-down image of the copper rod billet drawing can be calculated and recorded as (t1_base / 2 + t2_base / 2, f1_base / 2 + f2_base / 2).

[0086] Calculate the coefficient k. If t1_base - t2_base < 0, it means that the copper rod billet drawing is skewed in the direction as Figure 7 shown, and the slope of its center line is negative, then k takes -1; if t1_base - t2_base > 0, it means that the copper rod billet drawing is skewed in the direction as Figure 8 shown, and the slope of its center line is positive, then k takes 1;

[0087] Calculate the line with k·tanθ as the slope and passing through the center point O(t1_base / 2 + t2_base / 2, f1_base / 2 + f2_base / 2). This line is the top-down center line.

[0088] In step S50, the recognition steps of the two long sides in the top-down contour shape are as follows:

[0089] If t1_base - t2_base < 0, it means that the copper rod billet drawing is skewed in the direction as Figure 7 shown, then the part on F1 with an abscissa greater than t1_base is one long side, and the part on F2 with an abscissa less than t2_base is the other long side;

[0090] If t1_base - t2_base > 0, it means that the copper rod billet drawing is skewed in the direction as Figure 8 shown, then the part on F1 with an abscissa less than t1_base is one long side, and the part on F2 with an abscissa greater than t2_base is the other long side.

[0091] The present invention also relates to a copper rod billet drawing straightness detection device based on laser detection, which is applicable to the above-mentioned copper rod billet drawing straightness detection method based on laser detection. As Figures 1 - 2 shown, it includes:

[0092] A cutting module for cutting the copper rod billet.

[0093] A conveyor belt 1 for driving the movement of the copper rod billet.

[0094] A dot laser emitter 2 is arranged on the conveyor belt 1, and the irradiation direction is perpendicular to the conveyor belt 1.

[0095] A receiver 3 is arranged on the conveyor belt 1 for receiving the dot laser.

[0096] The dot laser emitter 2 and the receiver 3 are installed in an adjustable height manner so that they can be correspondingly adjusted according to copper rod billets of different diameters.

[0097] A line laser emitter 4 is arranged above the conveyor belt 1 for irradiating a line laser onto the conveyor belt 1. The line laser emitter 4 is installed in a rotatable manner so that the irradiation angle of the line laser emitter 4 can be adjusted by personnel.

[0098] A camera 5 is arranged above the conveyor belt 1 for obtaining a top view image.

[0099] A calculation module for obtaining the data of the receiver 3 and the camera 5 and calculating the straightness of the copper rod billet.

[0100] In order to make each laser more obvious and facilitate the identification of the laser, a covering hood can also be installed on this device. The dot laser emitter 2, the receiver 3, the line laser emitter 4 and the camera 5 are all arranged inside the covering hood.

[0101] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for detecting the straightness of a copper rod casting based on laser detection, characterized in that the steps include: S10: Obtain a copper rod with a length of L; S20: Make the copper rod casting do uniform linear motion at a speed of V; S30: a point laser is set to irradiate in the horizontal direction and perpendicular to the moving direction of the copper rod blank. The point laser is aligned with the center of the copper rod blank in height. A receiver is set to receive the point laser. The placement angle of the copper rod blank is calculated according to the time when the point laser is blocked. The specific process of calculating the placement angle of the copper rod blank is as follows: When the point laser is blocked, the timing starts from 0, the total blocked time is recorded as T, the copper rod blank diameter is D, and the copper rod blank placement angle is θ; Let V·T=L·cosθ+D·sinθ; Solve to obtain the value of the placement angle θ of the copper rod blank; S40: a line laser is set to illuminate the motion path of the copper rod blank, and an angle is formed between the irradiation direction of the line laser and the motion direction of the copper rod blank, a camera is set to capture a top view image at the line laser, and a top view profile of the copper rod blank is displayed by the line laser to obtain a top view profile shape of the copper rod blank; the specific steps of obtaining the top view profile shape of the copper rod blank are: When the point laser is blocked, start timing from 0 and continue recording the time t; Set the recognition range, which is between the projections of the point laser and the line laser onto the copper rod casting motion path; When the copper rod blank enters the recognition range, the line laser will irradiate the copper rod blank to form a laser curve. The camera takes a top-view image and recognizes the laser curve in the top-view image. The positions of the two ends of the laser curve in the direction perpendicular to the copper rod blank movement line are f1 and f2 respectively. As the copper rod moves, when t takes different values, there will be corresponding f1 and f2, thus forming two functions F1 and F2 with time t as the independent variable and f1 and f2 as the dependent variables respectively; By drawing F1 and F2 images on the same coordinate system, we can get the top view contour shape; S50: Calculate the top view center line of the copper rod blank according to the placement angle and the top view contour shape, then calculate the distance between each point on the two long sides of the top view contour shape of the copper rod blank and the top view center line, find the difference between the maximum distance and the minimum distance, and judge whether the difference exceeds the set threshold. If it exceeds, the copper rod blank is judged as unqualified in straightness. The specific process of calculating the top view center line is as follows: The point on the F1 image that is farthest from the F2 image is taken as (t1_base, f1_base), and the point on the F2 image that is farthest from the F1 image is taken as (t2_base, f2_base); Calculate the coefficient k. If t1_base-t2_base<0, k is -1; if t1_base-t2_base>0, k is 1; Calculate a straight line with a slope of k·tanθ that passes through the point (t1_base / 2+t2_base / 2, f1_base / 2+f2_base / 2). This straight line is the top-down centerline.

2. The method for detecting the straightness of copper rod casting based on laser detection according to claim 1 is characterized in that: In step S30, multiple point lasers and multiple receivers are set, each point laser calculates the value of the placement angle of the copper rod casting once, and finally all calculated placement angle values ​​are averaged as the final placement angle θ.

3. The method for detecting the straightness of copper rod casting based on laser detection according to claim 2, characterized in that: Step S30 also includes a verification step, specifically: When any point laser is blocked, the timing starts from 0. If the point laser adjacent to the point laser is blocked within the set time T1, the subsequent steps will continue to be executed; if it is not blocked, it will be determined whether the point laser is still in the blocked state within the set time T1. If so, an alarm will be issued and the detection will be stopped; if not, the data recorded this time will be cleared.

4. The method for detecting the straightness of copper rod casting based on laser detection according to claim 1, characterized in that: After the camera takes the image, it is binarized to form the final overhead image.

5. The method for detecting the straightness of copper rod casting based on laser detection according to claim 1, characterized in that: In step S50, the steps of identifying the two long sides of the top view contour shape are as follows: If t1_base-t2_base<0, the part on F1 with a horizontal coordinate greater than t1_base is one long side, and the part on F2 with a horizontal coordinate less than t2_base is another long side; If t1_base-t2_base>0, the portion on F1 whose horizontal coordinate is less than t1_base is one long side, and the portion on F2 whose horizontal coordinate is greater than t2_base is another long side.

6. A copper rod casting straightness detection device based on laser detection, suitable for the copper rod casting straightness detection method based on laser detection as described in any one of claims 1 to 5, characterized in that: include: Cutting module, used for cutting copper rod blanks; Conveyor belt, used to drive the copper rod to draw the blank; A point laser emitter is arranged on the conveyor belt, and the irradiation direction is perpendicular to the conveyor belt; A receiver, arranged on the transmission belt, for receiving the point laser; A line laser emitter, disposed above the conveyor belt, for irradiating a line laser onto the conveyor belt; A camera, arranged above the conveyor belt, for acquiring a top-view image; A calculation module is used to obtain the data of the receiver and the camera and calculate the straightness of the copper rod drawn.

7. The copper rod casting straightness detection device based on laser detection according to claim 6 is characterized in that: The invention also comprises a cover, wherein the point laser transmitter, the receiver, the line laser transmitter and the camera are all arranged in the cover.

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