Strip steel transverse flatness measurement method and system based on multi-laser vision sensing

Abstract

The present application belongs to the technical field of metallurgical equipment intelligence, and provides a strip steel transverse flatness measurement method and system based on multiple laser vision sensors, comprising: sequentially installing a laser speed measuring instrument, a first set of laser vision devices, a second set of laser vision devices and a third set of laser vision devices on a support above a strip steel roller, and collecting laser stripe images on the surface of the running strip steel; performing ROI region processing on the laser stripe images to identify the laser stripes in the laser stripe images; using a gray center of gravity method to extract the center coordinates of the laser stripes, and using a least squares method to fit the center coordinates to obtain a fitting equation; performing vibration filtering on the fitting equation, setting a vibration compensation term, calculating the strip steel transverse flatness, and adjusting the equipment parameters of the rolling mill and the straightening machine and the placement position of the flattening machine pad based on the strip steel transverse flatness. The present application realizes high-precision dynamic detection of the flatness of the strip steel.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metallurgical equipment intelligence, and particularly relates to a strip steel transverse flatness measurement method and system based on multi-laser vision sensing. BACKGROUND

[0002] In the production process of strip steel plates, flatness measurement is an indispensable production process, which can not only ensure product size precision and appearance quality, but also improve subsequent processing efficiency, reduce scrap rate, and meet the stringent requirements of high-end application fields. However, the current stage of strip steel plate flatness detection is heavily dependent on manual work, and the worker uses a ruler or a straight ruler to tightly adhere to the surface of the steel plate, and measures the gap between the ruler and the steel plate by the naked eye or the ruler to determine the flatness of the strip steel plate. This method not only relies heavily on manual experience, but also can only detect local flatness. Moreover, for the strip steel produced by the hot rolling production line, the surface temperature is high and cannot be directly measured. Flatness is a necessary process in the production process of strip steel, which needs to be measured not only after rolling, but also after straightening. The flatness measurement at this stage can feedback signals to adjust the rolls and straightening rolls to improve the flatness requirements of the strip steel. In addition, for finished strip steel plates, the flatness needs to be adjusted according to the flatness requirements of different users, and the flatness information of the strip steel plate needs to be adjusted before the flattening operation to achieve the purpose of improving the flatness. However, the previous operation relies heavily on manual work. In recent years, the non-contact measurement method has emerged, which uses laser vision, but can only measure the longitudinal flatness, and the measurement accuracy is heavily dependent on the number of laser lines. Moreover, during the measurement process, only large wave types can be measured, and small wave types cannot be measured. If small wave types need to be measured, the number of laser lines needs to be increased. The measurement result is the regional flatness, and the specific position of the concave-convex degree cannot be determined, so although it can be used after the rolling mill and the straightening machine, it cannot be used at the flattening machine. (The flattening machine needs to know the specific position of the concave-convex degree to place the flattening pad according to the specific position of the concave-convex degree). SUMMARY

[0003] To solve the problems existing in the prior art, the application provides a strip steel transverse flatness measurement method and system based on multi-laser vision sensing, which improves the detection accuracy and practicality.

[0004] To achieve the above-mentioned purpose, the application provides the following solutions:

[0005] The strip steel transverse flatness measurement method based on multi-laser vision sensing comprises:

[0006] The laser speed measuring instrument, the first set of laser vision device, the second set of laser vision device and the third set of laser vision device are sequentially installed on the support above the strip steel roller, and the laser stripe image of the running strip steel surface is collected; wherein, the laser speed measuring instrument is used for measuring the running speed of the strip steel roller, and the running speed of the strip steel roller is used for adjusting the distance between the laser vision devices;

[0007] The ROI region processing is performed on the laser stripe image, and the laser stripe in the laser stripe image is identified;

[0008] The center coordinates of the laser stripe are extracted by using the gray center of gravity method, and the least square method is used to fit the center coordinates to obtain a fitting equation;

[0009] The fitting equation is subjected to vibration filtering, and a vibration compensation term is set to calculate the transverse flatness of the strip steel, and based on the transverse flatness of the strip steel, the device parameters of the rolling mill, the straightening machine and the placement position of the pad of the flattening machine are adjusted.

[0010] Preferably, the three sets of laser vision devices each include a laser generator and a camera; the distance between the laser speed measuring instrument and the first set of laser vision device and the distance between the first set of laser vision device and the second set of laser vision device are constant values; the distance between the second set of laser vision device and the third set of laser vision device is a variable value, and the formula for adjusting the variable value is as follows:

[0011] ;

[0012] Wherein, is the distance between the second set of laser vision device and the third set of laser vision device; is the reference distance; is the speed adjustment coefficient; is the actual running speed of the strip steel roller measured by the laser speed measuring instrument; is the reference speed, that is , wherein is the maximum value of the running speed of the strip steel roller, is the minimum value of the running speed of the strip steel roller.

[0013] Preferably, before collecting the laser stripe image of the running strip steel surface, a conversion relationship between the world coordinate system and the image pixel coordinate system is established, and the laser vision device is calibrated based on the conversion relationship; the conversion relationship is as follows:

[0014] ;

[0015] Wherein, is the focal length of the camera, , are the physical dimensions of a pixel in the x and y axes, is the image coordinate system, (x, y) is the image pixel center coordinate, is the world coordinate system is the rotation matrix from the world coordinate system to the camera coordinate system is the translation matrix from the world coordinate system to the camera coordinate system .

[0016] Preferably, the method for performing ROI region processing on the laser stripe image comprises:

[0017] starting from the upper left corner of the laser stripe image, performing column-by-column search, when the pixel threshold of a certain pixel grid is higher than the preset threshold, switching to continuous search based on 8-neighbor chain code; in the continuous search based on 8-neighbor chain code, if more than 3 pixel grids in the 0, 1, and 2 chain code directions are continuously detected to exceed the preset threshold, it is determined that the corresponding position is an upper boundary point of the laser stripe, otherwise it is regarded as a noise point and is filtered out;

[0018] in the search process, a random function is used to generate irregular step lengths for column-to-column jumping until the search is completed, and the highest point of the upper boundary of the laser stripe and the lowest point of the upper boundary are obtained;

[0019] taking the highest point of the upper boundary of the laser stripe as a reference, expanding 2 pixels upward as the upper boundary of the laser stripe image, and taking the lowest point of the upper boundary of the laser stripe as a reference, expanding 5 pixels downward as the lower boundary of the laser stripe image;

[0020] based on the upper boundary and the lower boundary of the laser stripe image, the ROI region is obtained.

[0021] Preferably, the method for extracting the center coordinate of the laser stripe comprises:

[0022] for the preset upper boundary point of the laser stripe, a horizontal gray center of gravity method and a vertical gray center of gravity method are used to calculate the center point, and a triangle is constructed together with the preset upper boundary point;

[0023] the center point of the triangle is taken as the center point of the laser stripe, and the center coordinate is obtained.

[0024] Preferably, the solving formula of the strip steel transverse flatness is as follows:

[0025] ;

[0026] wherein, and are adjustment coefficients,​ is a vibration compensation term; is an actual running speed of the strip roller measured by the laser speedometer;

[0027] are fitting equations, wherein, represents a distance between the first set of laser vision devices and the second set of laser vision devices, represents a distance between the second set of laser vision devices and the third set of laser vision devices, represents and are mean values, represents a standard deviation.

[0028] The application also provides a strip transverse flatness measurement system based on multi-laser vision sensing, which is used to implement the method and comprises:

[0029] an image acquisition module, configured to sequentially install a laser speedometer, a first set of laser vision devices, a second set of laser vision devices and a third set of laser vision devices on a support above a strip roller, and acquire a laser stripe image of a running strip surface; wherein the laser speedometer is configured to measure a running speed of the strip roller, and the running speed of the strip roller is configured to adjust a distance between the laser vision devices;

[0030] an ROI identification module, configured to perform ROI region processing on the laser stripe image, and identify a laser stripe in the laser stripe image;

[0031] a coordinate fitting module, configured to extract a center coordinate of the laser stripe by using a gray center of gravity method, and fit the center coordinate by using a least square method, to obtain a fitting equation;

[0032] a transverse flatness solving module, configured to filter out vibration from the fitting equation, set a vibration compensation term, solve a strip transverse flatness, and adjust equipment parameters of a rolling mill, a straightening machine and a placement position of a flattening machine pad based on the strip transverse flatness.

[0033] Preferably, in the image acquisition module, the three sets of laser vision devices each comprise a laser generator and a camera; the distance between the laser speedometer and the first set of laser vision devices and the distance between the first set of laser vision devices and the second set of laser vision devices each adopt a fixed value; the distance between the second set of laser vision devices and the third set of laser vision devices adopts a variable value, and a formula for adjusting the variable value is as follows:

[0034] ​​​​​ ;

[0035] wherein, is the distance between the second set of laser vision devices and the third set of laser vision devices; is the reference distance; is the speed adjustment coefficient; is the actual running speed of the strip steel roller measured by the laser speed measuring instrument; is the reference speed, i.e. wherein is the maximum value of the running speed of the strip steel roller, is the minimum value of the running speed of the strip steel roller.

[0036] Compared with the prior art, the beneficial effects of the present application are:

[0037] 1. The distance between the three laser vision devices is set to an unequal distance structure, which can effectively filter out the influence of interference on flatness.

[0038] 2. The laser plane is perpendicular to the surface of the strip steel plate, which can reduce the widening phenomenon of the laser stripe and improve the extraction accuracy of the center line of the laser stripe.

[0039] 3. The data of the laser speed measuring instrument can be fused, which can adjust the distance between the three laser vision devices on the one hand and measure the length of the strip steel on the other hand to determine the length direction coordinate of the strip steel.

[0040] 4. The strip steel transverse flatness is measured, which can be detected by the laser vision device, and the detected flatness is the flatness of the entire width of the strip steel plate, not the local flatness measured by the longitudinal method. Moreover, the flatness data measured by the three laser vision devices and the data measured by the laser speed measuring instrument are fused to determine the flatness of the strip steel plane at any position. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the present application, the following briefly introduces the drawings needed to be used in the embodiments. Obviously, the drawings described in the following embodiments are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0042] Figure 1 is the flow chart of the strip steel transverse flatness measurement method based on multiple laser vision sensing of the embodiment of the present application;

[0043] Figure 2 is the layout diagram of the laser speed measuring instrument and the laser vision device of the embodiment of the present application;

[0044] Figure 3This is a schematic diagram of laser stripe search according to an embodiment of the present invention;

[0045] Figure 4 This is a schematic diagram of the neighborhood chain code in Embodiment 8 of the present invention;

[0046] Figure 5 This is a schematic diagram of the coordinate system of the strip steel plate to be tested in an embodiment of the present invention. Detailed Implementation

[0047] 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, and 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.

[0048] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] Example 1:

[0050] like Figure 1 As shown, the method for measuring the transverse straightness of strip steel based on multi-laser vision sensing includes:

[0051] S1: A laser velocimeter, a first set of laser vision devices, a second set of laser vision devices, and a third set of laser vision devices are sequentially installed on the support above the strip conveyor to collect laser stripe images of the running strip surface; among them, the laser velocimeter is used to measure the running speed of the strip conveyor, and the running speed of the strip conveyor is used to adjust the spacing between the laser vision devices. Figure 2 As shown.

[0052] Each of the three laser vision devices consists of a laser generator and a camera. The central axis of the camera is at a certain angle to the central axis of the laser generator, and the laser plane is perpendicular to the plane of the strip steel. Their arrangement is shown in the attached figure. Figure 2 As shown. This arrangement facilitates the formation of a triangular relationship, making measurement easier. Furthermore, by ensuring the laser plane is perpendicular to the strip, it eliminates laser line broadening caused by the angle. Laser line broadening weakens the laser line's brightness and reduces the accuracy of laser line centerline extraction.

[0053] A further implementation method involves using fixed values ​​for the distances between the laser velocimeter and the first laser vision device, as well as between the first and second laser vision devices. This facilitates the measurement of the strip roller conveyor's running speed, allowing for adjustments to the spacing between the laser vision devices. It also facilitates the determination of the strip length, thus determining the coordinates of the steel plate's running direction. The distance between the second and third laser vision devices is a variable value, and the formula for adjusting this variable value is as follows:

[0054] ;

[0055] in, The distance between the second and third laser vision devices; The reference spacing is the specific value of the distance between the first set of laser vision devices and the second set of laser vision devices. This is the speed adjustment coefficient; The actual running speed of the strip roller conveyor as measured by a laser velocimeter; For reference speed, i.e. ,in This represents the maximum operating speed of the strip steel roller conveyor. This represents the minimum operating speed of the strip steel roller conveyor.

[0056] The third laser vision device is equipped with an adjustment mechanism, such as... Figure 2 As shown, the adjustment mechanism is driven by a servo motor, which rotates a gear on a rack to adjust the distance between the second and third laser vision devices.

[0057] A further implementation involves establishing a world coordinate system before acquiring laser stripe images of the strip surface. Image pixel coordinate system The conversion relationship between these relationships is used to calibrate the laser vision device; the conversion relationship is as follows:

[0058] ;

[0059] in, For the camera's focal length, , They are pixels in The physical dimensions of the shaft. For the image coordinate system, ( () represents the coordinates of the center of the image pixels, which is also the coordinates of the image origin. World coordinate system To the camera coordinate system The rotation matrix, World coordinate system translation matrix to the camera coordinate system. .

[0060] S2: ROI region processing is performed on the laser stripe image to identify the laser stripe in the laser stripe image. The ROI region is set according to the thickness range of the strip steel in the production line, and the principle of setting the ROI region is that the laser stripe can be identified in the ROI region regardless of the thickness of the strip steel in the production line. The purpose of setting the ROI region is to speed up the image processing speed and improve the real-time performance of the entire system.

[0061] Further embodiments are directed to a method for performing ROI region processing on a laser stripe image, comprising:

[0062] The laser stripe is a straight line, which will be deformed when irradiated onto an object, forming an inclined straight line or an arc. According to this characteristic of the light stripe, a column-by-column search is performed from the top left corner of the laser stripe image, and when the pixel threshold of a certain pixel grid is higher than the preset threshold, a continuous search based on 8-neighbor chain code is performed. In the continuous search based on 8-neighbor chain code, if more than 3 pixel grids in the 0, 1, and 2 chain code directions are continuously detected to exceed the preset threshold, the corresponding position is determined as an upper boundary point of the laser stripe, otherwise it is considered as a noise point and is filtered out.

[0063] In the search process, a random function is used to generate irregular step lengths for column-to-column jumping until the search is completed, obtaining the highest point of the upper boundary of the laser stripe and the lowest point of the upper boundary. The purpose of using irregular step lengths is to avoid the randomness caused by regular step lengths and greatly shorten the search time. As shown in FIGS. 8 and 9. Figure 3 , Figure 4

[0064] Taking the highest point of the upper boundary of the laser stripe as a reference, 2 pixels are expanded upwards as the upper boundary of the laser stripe image, and taking the lowest point of the upper boundary of the laser stripe as a reference, 5 pixels are expanded downwards as the lower boundary of the laser stripe image.

[0065] Based on the upper boundary and the lower boundary of the laser stripe image, the ROI region is obtained. This ROI determination method takes into account the different positions of the laser stripe caused by different thicknesses of the strip steel in the actual image, greatly reduces the ROI region, can further speed up the image processing time, and can also filter out part of the noise points.

[0066] ​S3: the center coordinates of the laser stripe are extracted by using the gray center method, and the center coordinates are fitted by using the least square method to obtain a fitting equation. The purpose of this step is to obtain more accurate flatness information. The extracted laser stripe center line is fitted, and before fitting, the noise points are removed to increase the fitting accuracy. After ROI processing, the image area will become very small, and we obtain the upper boundary points of the laser stripe, on the basis of which the laser stripe center line is obtained.

[0067] Further embodiments are that the method for extracting the center coordinates of the laser stripe comprises:

[0068] For the preset upper boundary points of the laser stripe, the center points are obtained by using the horizontal gray center method and the vertical gray center method respectively, and a triangle is constructed together with the preset upper boundary points; the horizontal gray center method is performed at the preset upper boundary point to obtain a center point, the vertical center method is performed to obtain a center point, and then the three points constitute three vertices of a triangle.

[0069] The center point of the triangle is taken as the center point of the laser stripe to obtain the center coordinates.

[0070] This operation is beneficial to avoid the center extraction error caused by a single horizontal gray center method or a single vertical gray center method. Because the horizontal gray center method is good for extracting the center of the horizontal laser stripe, the vertical gray center method is good for extracting the center of the vertical laser stripe, but the extraction effect of the curved line or the inclined line is limited. This method can effectively overcome the shortcomings of the single horizontal or single vertical gray center method in extracting the center of the curved line or the inclined line laser stripe.

[0071] In this embodiment, the laser stripe center coordinates extracted by the gray center method are fitted, the fitting method is the least square method, the slope and the intercept are obtained. The is taken as the slope threshold value. Then, the slope between adjacent center points is calculated in turn. When the is different from the slope threshold value, and exceeds a certain threshold value, the is optimized in weight. The weight optimization strategy is as follows:

[0072] , wherein and are values for limiting the slope change.

[0073] After image processing and laser stripe center line fitting, three fitting equations can be obtained, which are , and In the obtained fitting equation, not only the strip transverse flatness information is contained, but also the vibration information of the strip running on the roller is contained.

[0074] S4: vibration filtering is performed on the fitting equation, a vibration compensation term is set, the strip transverse flatness is solved, and based on the strip transverse flatness, the equipment parameters of the rolling mill and the straightening machine and the placement position of the flattening machine pad are adjusted.

[0075] Further embodiments are that the solving formula of the strip transverse flatness is as follows:

[0076] ;

[0077] wherein, and is an adjustment coefficient, is a vibration compensation term; is the actual running speed of the strip roller measured by the laser speedometer;

[0078] , , and are fitting equations, wherein, , , represents the distance between the first set of laser vision devices and the second set of laser vision devices, represents the distance between the second set of laser vision devices and the third set of laser vision devices, represents and are mean values, represents a standard deviation.

[0079] Thus, the transverse flatness information of the strip rolled by the rolling mill is solved, and according to the requirements of the process specification on the flatness, the radial force of the rolling mill roll is adjusted to improve the transverse flatness so as to meet the requirements of the process specification.

[0080] In the present embodiment, the laser speedometer and the three sets of laser vision devices can be arranged at:

[0081] The transverse flatness of the strip at the outlet of the rolling mill is detected, the transverse flatness information of the strip rolled by the rolling mill is solved by steps S1-S4, and according to the requirements of the process specification on the transverse flatness, the radial force of the rolling mill roll is adjusted to improve the transverse flatness so as to meet the requirements of the process specification.

[0082] The strip steel at the outlet of the straightening machine is detected for transverse flatness on the roller table at the outlet of the straightening machine; the flatness information of the strip steel straightened by the straightening machine is obtained by steps S1-S4, and the roll gap of the straightening machine is adjusted in real time in combination with the process specification requirements, so as to improve the transverse flatness of the strip steel.

[0083] The strip steel at the inlet of the straightening machine is detected for transverse flatness on the roller table at the inlet of the straightening machine. On the basis of obtaining the transverse flatness information of the strip steel, the length data of the strip steel obtained by the laser speed measuring instrument is combined to establish a coordinate system as shown in Figure 5 The axis data is the length data of the strip steel obtained by the laser speed measuring instrument, and the axis data is the flatness data obtained. Figure 5 The flatness measuring device described in the specification is the laser speed measuring instrument, the first set of laser vision devices, the second set of laser vision devices, and the third set of laser vision devices. The two parts of data are combined to obtain the flatness information of the strip steel plane at any coordinate position. For example, the flatness information of the strip steel plane at any coordinate position The transverse flatness of the strip steel at the position The transverse flatness of the strip steel at the position is the upper limit of the transverse flatness of the strip steel specified in the process specification, that is, the pad of the flattening machine is placed on the front surface of the strip steel The transverse flatness of the strip steel at the position is the lower limit of the flatness of the strip steel specified in the process specification, that is, the pad of the flattening machine is placed on the back surface of the strip steel . This guides the flattening machine to flatten the strip steel to meet the flatness required by the process specification.

[0084] Example 2:

[0085] The application also provides a strip steel transverse flatness measuring system based on multiple laser vision sensors, which is used to realize the method and comprises:

[0086] An image acquisition module is used to sequentially install a laser speed measuring instrument, a first set of laser vision devices, a second set of laser vision devices, and a third set of laser vision devices on a support above a strip steel roller, and to acquire laser stripe images on the surface of the running strip steel; wherein the laser speed measuring instrument is used to measure the running speed of the strip steel roller, and the running speed of the strip steel roller is used to adjust the spacing between the laser vision devices.

[0087] An ROI identification module is used to perform ROI region processing on the laser stripe images to identify the laser stripes in the laser stripe images.​​​​​​

[0088] The coordinate fitting module is configured to extract the center coordinates of the laser stripe by using a gray center of gravity method, and fit the center coordinates by using a least square method to obtain a fitting equation.

[0089] The transverse flatness solving module is configured to perform vibration filtering on the fitting equation, set a vibration compensation term, solve the transverse flatness of the strip steel, and adjust the equipment parameters of the rolling mill and the straightening machine and the placement position of the flattening machine pad based on the transverse flatness of the strip steel.

[0090] Further, in the image acquisition module, the three sets of laser vision devices each include a laser generator and a camera; the distance between the laser speed measuring instrument and the first set of laser vision devices and the distance between the first set of laser vision devices and the second set of laser vision devices are fixed values; the distance between the second set of laser vision devices and the third set of laser vision devices is a variable value, and the formula for adjusting the variable value is as follows:

[0091] ;

[0092] wherein, is the distance between the second set of laser vision devices and the third set of laser vision devices; is a reference distance; is a speed adjustment coefficient; is the actual running speed of the strip steel roller measured by the laser speed measuring instrument; is a reference speed, i.e. wherein, is the maximum value of the running speed of the strip steel roller, is the minimum value of the running speed of the strip steel roller.

[0093] The above-described embodiments are only descriptions of the preferred modes of the present application and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A method for measuring the transverse straightness of strip steel based on multi-laser vision sensing, characterized in that, include: A laser velocimeter, a first set of laser vision devices, a second set of laser vision devices, and a third set of laser vision devices are sequentially installed on a support above the strip steel conveyor to collect laser stripe images on the surface of the running strip steel. The laser velocimeter is used to measure the running speed of the strip steel conveyor, and the running speed of the strip steel conveyor is used to adjust the spacing between the laser vision devices. The laser stripe image is processed by the Region of Interest (ROI) to identify the laser stripes in the image; The center coordinates of the laser stripe are extracted using the gray-scale centroid method, and the center coordinates are fitted using the least squares method to obtain the fitting equation. Vibration filtering is performed on the fitted equation, and a vibration compensation term is set to obtain the transverse straightness of the strip. Based on the transverse straightness of the strip, the equipment parameters of the rolling mill and straightening machine, as well as the placement position of the flattening machine pad, are adjusted. All three laser vision devices include a laser generator and a camera; the distance between the laser velocimeter and the first laser vision device, as well as the distance between the first and second laser vision devices, are constant values; the distance between the second and third laser vision devices is a variable value, and the formula for adjusting the variable value is as follows: ； in, The distance between the second and third laser vision devices; The reference spacing; This is the speed adjustment coefficient; The actual running speed of the strip roller conveyor as measured by a laser velocimeter; For reference speed, i.e. ,in This represents the maximum operating speed of the strip steel roller conveyor. This represents the minimum operating speed of the strip steel roller conveyor.

2. The method according to claim 1, characterized in that, Before acquiring laser stripe images of the strip surface, a world coordinate system is established. Image pixel coordinate system The conversion relationship between the two is used to calibrate the laser vision device; the conversion relationship is as follows: ； in, For the camera's focal length, , They are pixels in The physical dimensions of the shaft. For the image coordinate system, ( () represents the center coordinates of the image pixels. World coordinate system To the camera coordinate system The rotation matrix, World coordinate system To the camera coordinate system The translation matrix.

3. The method according to claim 1, characterized in that, The method for performing ROI region processing on the laser stripe image includes: Starting from the top left corner of the laser stripe image, a column-by-column search is performed. When the pixel threshold of a certain pixel cell is found to be higher than a preset threshold, the search switches to a continuous search based on the 8-neighborhood chain code. During the continuous search based on the 8-neighborhood chain code, if more than 3 pixels are detected consecutively in the 0, 1, and 2 chain code directions and all exceed the preset threshold, the corresponding position is determined to be the upper boundary point of the laser stripe; otherwise, it is regarded as a noise point and filtered out. During the search process, an irregular step size is generated by a random function to jump between columns until the search is completed, and the highest point and the lowest point of the upper boundary of the laser stripe are obtained. Based on the highest point of the upper boundary of the laser stripe, expand upward by 2 pixels to form the upper boundary of the laser stripe image; based on the lowest point of the upper boundary of the laser stripe, expand downward by 5 pixels to form the lower boundary of the laser stripe image. The ROI region is obtained based on the upper and lower boundaries of the laser stripe image.

4. The method according to claim 1, characterized in that, The method for extracting the center coordinates of the laser stripe includes: The center point of the laser stripe is obtained by using the horizontal gray-scale centroid method and the vertical gray-scale centroid method respectively, and a triangle is constructed together with the preset upper boundary point. The center point of the triangle is used as the center point of the laser stripe to obtain the center coordinates.

5. The method according to claim 1, characterized in that, The formula for calculating the transverse straightness of the strip is as follows: ； in, and To adjust the coefficient, For vibration compensation; The actual running speed of the strip roller conveyor as measured by a laser velocimeter; ； , and All are fitted equations, where, , , This indicates the distance between the first and second laser vision devices. This indicates the distance between the second and third laser vision devices. express and mean It represents the standard deviation.

6. A strip steel transverse straightness measurement system based on multi-laser vision sensing, used to implement the method described in any one of claims 1-5, characterized in that, include: The image acquisition module is used to sequentially install a laser velocimeter, a first set of laser vision devices, a second set of laser vision devices, and a third set of laser vision devices on a support above the strip steel roller conveyor to acquire laser stripe images on the surface of the running strip steel; wherein, the laser velocimeter is used to measure the running speed of the strip steel roller conveyor, and the running speed of the strip steel roller conveyor is used to adjust the spacing between the laser vision devices. The ROI recognition module is used to process the ROI region of the laser stripe image and identify the laser stripes in the laser stripe image. The coordinate fitting module is used to extract the center coordinates of the laser stripe using the gray-scale centroid method, and to fit the center coordinates using the least squares method to obtain the fitting equation. The transverse straightness solution module is used to filter out vibrations from the fitted equation, set vibration compensation terms, calculate the transverse straightness of the strip, and adjust the equipment parameters of the rolling mill and straightening machine, as well as the placement position of the flattening machine pad based on the transverse straightness of the strip.

7. The system according to claim 6, characterized in that, In the image acquisition module, each of the three laser vision devices includes a laser generator and a camera; the distance between the laser velocimeter and the first laser vision device, as well as the distance between the first and second laser vision devices, are constant values; the distance between the second and third laser vision devices is a variable value, and the formula for adjusting the variable value is as follows: ； in, The distance between the second and third laser vision devices; The reference spacing; This is the speed adjustment coefficient; The actual running speed of the strip roller conveyor as measured by a laser velocimeter; For reference speed, i.e. ,in This represents the maximum operating speed of the strip steel roller conveyor. This represents the minimum operating speed of the strip steel roller conveyor.

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