An online measuring system and method for camber of steel plate

Abstract

The present invention discloses an on-line measuring system and method for camber of steel plates. The system includes a mounting bracket arranged above a steel plate conveying roller path. An installation seat is arranged on the mounting bracket, and a measuring device is arranged on the installation seat. The measuring device is arranged in a heat insulation box, and the heat insulation box is connected to an air cooling device. A dust-proof cover is arranged on one side of the heat insulation box facing the roller path. While cooling the measuring device, the air cooling device is also used to open the dust-proof cover and provide positive pressure purging. The present invention can accurately detect the camber value of steel plates in real time on-line.

Description

Technical Field

[0001] The present invention relates to the field of automated testing, and more particularly to an on-line measuring system for camber of steel plates, and also to an on-line measuring method for camber of steel plates. Background Art

[0002] The camber of the intermediate billet of hot-rolled steel plates is the main manifestation of the asymmetric defects of the slab in the rough rolling stage of hot rolling. The size of the camber, as one of the important indicators for evaluating the quality of steel plate products, directly affects the quality of the final steel plate products. Continuous casting steel plates are used as raw materials for rolling mills. The slab shape state of the raw materials directly affects the subsequent rolling process. When the camber seriously exceeds the standard, it is necessary to perform head cutting or closing to prevent damage to the production line equipment. The camber state of the intermediate steel plates in the rolling mill directly determines the control of the camber of the finished products. The accuracy of the camber measurement of the intermediate steel plates directly affects the adjustment of the process parameters of the rolling mill. Inaccurate or incorrect measurement will cause the steel plate to deviate, and in severe cases, accidents such as strip stacking during threading, tail flicking, and even coiling jamming will occur, affecting the stability of the rolling process.

[0003] There are currently two types of steel plate camber measurement systems in use. One is the off-line measurement method for camber of steel plates. Operators use visual inspection and a straightedge to measure the off-line steel plates, generally requiring three people to cooperate, and it is impossible to adjust the process in real time according to the camber data to optimize the rolling process of the steel plates. The second is to use a matrix CCD camera. Due to the camber problems of the steel plates such as warping and buckling at the head, it is necessary to consider the height change of the steel plate under the camera, and the measurement accuracy of the CCD will be affected. In the previous solutions, there is no accurate thickness value measurement, and the result error will be relatively large. Summary of the Invention

[0004] In order to solve the above problems in the prior art, the purpose of the present invention is to provide an on-line measuring system and method for camber of steel plates, which can accurately detect the camber value of the steel plate in real time on-line.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0006] On the one hand, the present invention provides an on-line measuring system for camber of steel plates, including a mounting bracket arranged above the steel plate conveying roller table. An installation seat is arranged on the mounting bracket, and a measuring device is arranged on the installation seat. The measuring device is arranged in a heat insulation box, the heat insulation box is connected to an air cooling device, a dust-proof cover is arranged on the side of the heat insulation box facing the roller table, and the air cooling device is used to cool the measuring device and also to open the dust-proof cover and provide positive pressure purging.

[0007] Optionally, the dust-proof cover is provided with a switching device, and the air cooling device opens the switching device through compressed air;

[0008] The switch device is provided with an automatic reset mechanism. When the air cooling device stops delivering compressed air to the switch device, the automatic reset mechanism drives the switch device to close.

[0009] Optionally, the heat insulation box is provided with a water cooling device.

[0010] Optionally, the measuring device includes a laser velocimeter, a CMOS area array camera, and a laser rangefinder.

[0011] Optionally, the laser velocimeter, the CMOS area array camera, and the laser rangefinder are longitudinally arranged along the steel plate conveying direction and are perpendicular to the conveying plane of the roller table.

[0012] Optionally, the CMOS area array camera is provided with a fixed-focus lens.

[0013] Optionally, the measuring device is 2500 - 6000 mm away from the plane of the roller table.

[0014] Optionally, the measuring device is electrically connected to a data processing system, and the data processing system is electrically connected to a display device and a rolling mill control system respectively.

[0015] Optionally, data is transmitted between the measuring device and the data processing system via a gigabit Ethernet cable or an optical fiber.

[0016] Optionally, two sets of the mounting brackets, the mounting seats, and the measuring devices are respectively arranged on both sides of the rolling mill, and the two sets of measuring devices are respectively used to measure steel plates rolled in different directions.

[0017] On the other hand, the present invention provides an on-line method for measuring the camber of a steel plate, including the following steps:

[0018] Step 1: Arrange a scanning device at the position of the center line of the unit directly above the roller table where the steel plate runs. The scanning device includes a CMOS area array camera, a laser velocimeter, and a laser rangefinder. According to the real-time speed of the steel plate running and the field of view size of the CMOS area array camera, calculate the image acquisition frequency of the CMOS area array camera and trigger the CMOS area array camera to acquire images.

[0019] Step 2: When the head of the steel plate passes through the scanning device on the roller table, the data processing system detects the head of the steel plate, starts measurement and records data. The CMOS area array camera takes pictures of the running steel plate, and at the same time, the laser velocimeter records the walking length ΔS of the steel plate.

[0020] Step 3: The data processing system records the image information in real time and stores the moving length ΔS of the steel plate.

[0021] Step 4: Based on the images detected by the CMOS area array camera, in each data scanning cycle, the data processing system corrects and outputs the steel plate width value and the value of the steel plate's deviation from the center once according to the steel plate thickness value output by the laser rangefinder.

[0022] Step 5: When the second image is taken, the steel plate has traveled a distance of ΔS. The data processing system calculates the deviation caused by the camber of the steel plate based on the pixel overlapping area between the second image and the previous image, and corrects the pixels of the previous image. When ΔS increases to S≥1000mm, the data processing system outputs the camber data of the steel plate over a length of S based on the recorded picture information. When the camber value exceeds the set threshold, the data processing system gives an alarm prompt.

[0023] Step 6: When it comes to the (N + 1)-th scanning cycle, where N is a natural number greater than 1, the data processing system outputs the camber value based on the data from the 2nd to the (N + 1)-th time. When the camber value exceeds the set threshold, the system gives an alarm prompt, and so on. When the tail of the entire steel plate passes through the scanning device, the data recording of this steel plate is completed.

[0024] Step 7: According to the edge data during the operation of the steel plate, connect the boundary value points at the head and tail of the steel plate to calculate a straight line, and then calculate the distance value of the edge value points of the entire steel plate deviating from this straight line, and further calculate and output the camber value of the entire steel plate. According to the setting, the data processing system gives a conclusion on whether the camber value of the steel plate meets the requirements: qualified or unqualified.

[0025] As can be seen from the above technical solutions, an online steel plate camber measurement system and measurement method provided by the present invention have the following advantages:

[0026] By setting up a heat insulation box, the present invention can effectively isolate the high temperature in the working environment, prevent the high temperature from damaging the measuring device, improve the stability of the device, and extend its service life.

[0027] By setting up an air cooling device to cool the measuring device, the present invention is also used to open the dust-proof cover of the heat insulation box and provide positive pressure purging to blow away dust, water vapor and other debris in front of the camera lens, thereby ensuring the cleanliness of the camera lens environment and ensuring the measurement accuracy.

[0028] By measuring the thickness change of the strip or steel plate during the rolling process, the present invention compensates the measurement results, has high measurement accuracy, and can send the data to the control system of the rough rolling mill, thereby realizing the online closed-loop control of the rolling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the steel plate camber.

[0030] Figure 2 Schematic diagram of the L-shaped camber of the steel plate

[0031] Figure 3 Schematic diagram of the on-line steel plate camber measurement system according to an embodiment of the present invention

[0032] Figure 4 Schematic diagram of the on-line steel plate camber measurement system according to an embodiment of the present invention

[0033] Figure 5 Schematic circuit diagram of the on-line steel plate camber measurement system according to an embodiment of the present invention

[0034] Figure 6 Coordinate diagram used for calibration of the CMOS area array camera according to an embodiment of the present invention

[0035] Explanation of reference numerals: 1, rolling mill; 2, roller table; 3, first mounting bracket; 4, first mounting seat; 5, first laser rangefinder; 6, first CMOS area array camera; 7, first laser speedometer; 8, second mounting bracket; 9, second mounting seat; 10, second laser rangefinder; 11, second CMOS area array camera; 12, second laser speedometer; 13, steel plate; 14, heat insulation box; 15, switch device; 16, dust cover Detailed implementation manners

[0036] In order to better understand the purpose, structure and function of the present invention, the following further describes in detail an on-line steel plate camber measurement system and a measurement method of the present invention with reference to the accompanying drawings

[0037] Figure 1 、 Figure 2 Schematic diagram of the camber of the steel plate Figure 2 Schematic diagram of the L-shaped camber. The camber A is defined as the maximum orthogonal distance between the head and tail connection lines of the strip or steel plate on the length L. According to the fluctuation of the measured center line position, the camber is calculated as an L-shaped camber or an S-shaped camber. If the center line fluctuates in one direction, it is judged as an L-shaped camber. If the fluctuation reaches a certain range above and below the center line, it is judged as an S-shaped camber

[0038] Embodiment 1

[0039] As Figure 3 、 Figure 4 、 Figure 5This is Embodiment 1 of the present invention. In this embodiment, an on-line measuring system for the camber of steel plates is disclosed, which includes a mounting bracket arranged above the steel plate conveying roller path 2. A mounting seat is provided on the mounting bracket, and a measuring device is provided on the mounting seat. The measuring device is arranged in a heat insulation box, and the heat insulation box is connected to an air cooling device. A dust-proof cover is provided on the side of the heat insulation box facing the roller path. While cooling the measuring device, the air cooling device is also used to open the dust-proof cover and provide positive pressure purging.

[0040] In this embodiment, by setting the heat insulation box, the high temperature in the working environment can be effectively isolated, preventing the measuring device from being damaged by high temperature, improving the stability of the device and extending its service life.

[0041] In this embodiment, while the air cooling device is used to cool the measuring device, it is also used to open the dust-proof cover of the heat insulation box (the dust-proof cover mainly provides protection for the CMOS area array camera), and provide positive pressure purging to blow away dust, water vapor and other sundries in front of the camera lens, so as to ensure the cleanliness of the camera lens environment and ensure the measurement accuracy.

[0042] As Figure 4 shown, the dust-proof cover 16 is provided with a switching device 15, and the air cooling device opens the switching device 15 through compressed air. The dust-proof cover 16 is located outside the heat insulation box 14, and the switching device 15 is located between the dust-proof cover 16 and the heat insulation box 14.

[0043] The air cooling device includes a compressed air source and a compressed air conveying pipeline. Components such as an electromagnetic switch valve, a display pressure regulating valve, a filter, a display pressure regulating valve, and a flow detection sensor are provided on the compressed air conveying pipeline. The compressed air conveying pipeline is respectively connected to the heat insulation box 14 and the switching device 15.

[0044] The air pressure regulated by the first display pressure regulating valve is 5 bar, and the relatively high pressure can be used to open the switching device 15. The air pressure regulated by the second display pressure regulating valve is 0.2 bar, and the relatively low pressure can be used to purge and cool the CMOS area array camera.

[0045] In this embodiment, the switching device 15 is provided with an automatic reset mechanism. When the air cooling device stops delivering compressed air to the switching device 15, the automatic reset mechanism drives the switching device 15 to close, which can effectively isolate dust, water vapor and other sundries and prevent the sundries from entering the heat insulation box.

[0046] The automatic reset mechanism can adopt methods such as gravity reset and elastic reset.

[0047] The heat insulation box is provided with a water cooling device, which can continuously cool the heat insulation box and protect the internal measuring device.

[0048] As Figure 3As shown in the figure, the measuring device includes a laser velocimeter, a CMOS area array camera, and a laser rangefinder.

[0049] The laser velocimeter is used to measure the length that the steel plate has traveled during movement.

[0050] The CMOS area array camera is used to capture images of the moving steel plate and output image information.

[0051] The laser rangefinder is used to measure the height change of the moving steel plate.

[0052] As Figure 3 shown in the figure, the laser velocimeter, the CMOS area array camera, and the laser rangefinder are longitudinally arranged along the conveying direction of the steel plate 13 and are perpendicular to the conveying plane of the roller table 2. Specifically, the optical axis of the lens of the CMOS area array camera is perpendicular to the conveying plane of the roller table 2, and the measuring beams emitted by the laser velocimeter and the laser rangefinder are perpendicular to the conveying plane of the roller table 2.

[0053] The CMOS area array camera is provided with a fixed-focus lens, which can improve the accuracy of the captured images. It can also be replaced according to the width of the measured steel plate, thereby changing the field of view and adapting to measurement systems of different widths. In this embodiment, the camera selects the Dalsa black-and-white CMOS area array camera Genie HMI 1400, and the lens is a Computar 16mm fixed-focus lens.

[0054] The measuring device is 2500 - 6000 mm away from the plane of the roller table 2. Preferably 4000 mm.

[0055] The laser velocimeter and the laser rangefinder can also be provided with dust covers, but since the strip steel or steel plate needs to be measured in real time, a switching device is not required. The air cooling device is used to cool the laser velocimeter and the laser rangefinder while providing positive pressure purging.

[0056] As Figure 5 shown in the figure, the measuring device is electrically connected to the data processing system, and the data processing system is electrically connected to the display device and the rolling mill control system respectively.

[0057] The data processing system is used to extract the pixel information of the picture and complete image stitching, calculate the strip width, position, and camber, and output the strip width and camber data through the bus.

[0058] Data transmission between the measuring device and the data processing system is carried out through a gigabit Ethernet cable or optical fiber, and the data transmission is fast and accurate.

[0059] As Figure 3 shown in the figure, two sets of mounting brackets, mounting seats, and measuring devices are respectively arranged on both sides of the rolling mill 1, and the two sets of measuring devices are respectively used to measure steel plates rolled in different directions.

[0060] AsFigure 3 As shown in the figure, a first mounting seat 4 is provided on the first mounting bracket 3, and a first measuring device is provided on the first mounting seat 4. The first measuring device includes a first laser rangefinder 5, a first CMOS area array camera 6, and a first laser velocimeter 7.

[0061] A second mounting seat 9 is provided on the second mounting bracket 8, and a second measuring device is provided on the second mounting seat 9. The second measuring device includes a second laser rangefinder 10, a second CMOS area array camera 11, and a second laser velocimeter 12.

[0062] Preferably, a large-flow air purging device can also be configured in the cross-sectional area of the entire measuring device to ensure that the measuring device in the camera's field of view can clearly capture images.

[0063] Embodiment 2

[0064] An on-line measuring method for the camber of a steel plate is provided in this embodiment, including the following steps:

[0065] Step 1: Arrange a scanning device at the position of the center line of the unit directly above the roller path where the steel plate runs. The scanning device includes a CMOS area array camera, a laser velocimeter, and a laser rangefinder. Calculate the image acquisition frequency of the CMOS area array camera according to the real-time speed of the steel plate running and the field of view size of the CMOS area array camera, and trigger the CMOS area array camera to acquire images.

[0066] Step 2: When the head of the steel plate passes through the scanning device on the roller path, the data processing system detects the head of the steel plate, starts the measurement and records the data. The CMOS area array camera takes pictures of the running steel plate, and at the same time the laser velocimeter records the running length ΔS of the steel plate.

[0067] Step 3: The data processing system records the picture information in real time and stores the moving length ΔS of the steel plate.

[0068] Step 4: According to the image detected by the CMOS area array camera, in each data scanning cycle, the data processing system corrects and outputs the width value of the steel plate and the value of the steel plate deviating from the center once according to the steel plate thickness value output by the laser rangefinder.

[0069] Step 5: When the second image is taken, the steel plate has traveled a distance of ΔS. The data processing system calculates the offset caused by the camber of the steel plate according to the pixel overlapping area part between the second image and the previous image, and corrects the pixels of the previous image. When ΔS increases to S≥1000mm, the data processing system outputs the camber data of the steel plate in the length of S according to the recorded picture information. When the camber value exceeds the set threshold, the data processing system gives an alarm prompt.

[0070] Step 6: When it comes to the (N + 1)-th scanning cycle, where N is a natural number greater than 1, the data processing system outputs the camber value based on the data from the 2nd to the (N + 1)-th time. When the camber value exceeds the set threshold, the system gives an alarm prompt. And so on. When the tail of the entire steel plate passes through the scanning device, the data recording of the steel plate is completed;

[0071] Step 7: According to the edge data during the operation of the steel plate, connect the boundary value points at the head and tail of the steel plate to calculate a straight line, then calculate the distance value of the edge value points of the entire steel plate deviating from this straight line, and further calculate and output the camber value of the entire steel plate. And according to the setting, the data processing system gives a conclusion on whether the camber value of the steel plate meets the requirements: qualified or unqualified.

[0072] By measuring the thickness change of the strip or steel plate during rolling, compensating the measurement results, with high measurement accuracy, and at the same time, the data can be sent to the control system of the rough rolling mill, so as to realize the online closed-loop control of the rolling process.

[0073] Through the online steel plate camber measurement system in Embodiment 1, the specific measurement method is as follows:

[0074] 1. Pre-install a CMOS area array camera, a laser speedometer, and a laser rangefinder on the installation bracket, arrange the installation bracket directly above the roller path where the steel plate runs, and install the data processing system in the on-site electrical room. The image information captured by the CMOS area array camera is input into the data processing system through Ethernet; the CMOS area array camera, the laser speedometer, and the laser rangefinder (the thickness measurement device of the strip or steel plate) are connected to the data processor, and the data processor converts the speed signal of the speedometer into a picture acquisition trigger signal of the camera for trigger acquisition; the data processor calculates the obtained image information, height information, and length information to obtain the shape and camber information of the steel plate.

[0075] 2. The CMOS area array camera is equipped with a fixed-focus lens, which can be replaced according to the width of the measured steel plate, so as to change the field of view and adapt to measurement systems of different widths.

[0076] 3. The CMOS area array camera, the laser speedometer, and the laser rangefinder are installed in an insulated control box with water-cooling protection. Each measuring device is equipped with a protection device and is separately equipped with an air cooling device to cool the entire measurement system; at the same time, the air cooling device is used to open the lens protection cover of the CMOS area array camera and provide positive pressure purging to ensure the cleanliness of the lens environment and the measurement accuracy.

[0077] 4. The CMOS area array camera communicates with the data processing system through Ethernet to transmit picture information.

[0078] 5. The laser speedometer adopts a laser length measurement system based on the Doppler frequency shift principle, and the system directly outputs absolute length information.

[0079] 6. The laser rangefinder transmits signals to the data processing system through 4 - 20mA analog signals.

[0080] 7. A large - flow air purging device is configured in the cross - sectional area of the entire measuring device to ensure that the measuring device within the camera's field of view can clearly capture images.

[0081] 8. The output of strip width and camber includes the following steps:

[0082] 8.1 Calibration of the laser rangefinder

[0083] Initialize and set the parameters of the laser distance measurement device. Take the length from the roller table plane to the rangefinder as the reference current signal of 4mA, and the length change of 300mm from the reference plane as the full - scale 20mA signal. Make corresponding parameter calibrations in the data processing system. Place a steel plate with a known thickness T1 on the roller table plane where the steel plate is running, start the distance measurement system, and check the difference between the feedback value of the measurement system and the actual thickness T1 in the data processing system.

[0084] 8.2 Coordinate system transformation and camera calibration

[0085] During the image measurement and recognition process, there are three coordinate system transformations, namely the coordinate system of the real world, the camera coordinate system, and the image coordinate system.

[0086] The world coordinate system can also be called the measurement coordinate system, which is a three - dimensional rectangular coordinate system. Based on it, the spatial position between the camera and the measured steel plate can be described.

[0087] The camera coordinate system is also a three - dimensional rectangular coordinate system. The origin is located at the optical center of the lens, the x and y axes are parallel to the two sides of the image plane respectively, and the z axis is the optical axis of the lens, perpendicular to the image plane.

[0088] The pixel coordinate system is a two - dimensional rectangular coordinate system of uov, which reflects the arrangement of pixels in the camera's CMOS chip. The origin o is located at the upper - left corner of the image, the u - axis and v - axis are parallel to the two sides of the image plane respectively. The unit of coordinates in the pixel coordinate system is pixel, which is an integer value.

[0089] The pixel coordinate system is not conducive to coordinate transformation. Therefore, it is necessary to establish an image coordinate system XOY. The unit of its coordinate axes is usually millimeters (mm), and the origin is the intersection point of the camera's optical axis and the image plane (called the principal point), that is, the center point of the image. The X - axis and Y - axis are parallel to the u - axis and v - axis respectively. Therefore, the two coordinate systems are actually in a translation relationship, that is, they can be obtained through translation.

[0090] The coordinate diagram is asFigure 6 as shown

[0091] a Conversion from the world coordinate system to the camera coordinate system

[0092]

[0093] where R is a 3×3 rotation matrix and T is a 3×1 translation vector represents the camera coordinate system represents the world coordinate system

[0094] b Conversion from the image coordinate system to the pixel coordinate system:

[0095]

[0096] where dX and dY are the physical sizes of pixels in the X and Y axis directions respectively, and u 0 , v 0 are the coordinates of the image origin

[0097] c Relationship between an arbitrary point P in space and its image point p. The line connecting P and the camera optical center o is oP, and the intersection point p of oP and the image plane is the projection of the spatial point P on the image plane. This process is perspective projection, which is represented by the following matrix:

[0098]

[0099] where s is a scaling factor (s≠0) and f is the effective focal length (distance from the optical center to the image plane) represents the homogeneous coordinates of the spatial point P in the camera coordinate system oxyz represents the homogeneous coordinates of the image point p in the image coordinate system XOY

[0100] d Conversion from the world coordinate system to the pixel coordinate system

[0101]

[0102] where a x =f / dX, a y =f / dY, which are called the scale factors of the u and v axes. M1 is called the camera internal parameter, M2 is called the camera external parameter, and M is called the projection matrix

[0103] e Place a black and white checkerboard with known dimensions on the plane where the roller table runs. The data processing system uses the checkerboard corner detection method in the OpenCV image processing function library under the C++ platform to calculate the internal parameter M1 and external parameter M2 of the CMOS area array camera, so as to obtain the corresponding relationship between the steel plate and the pixel points

[0104]

[0105] During the rolling process of the f steel plate, the thickness is constantly changing. Therefore, the above formula needs to be corrected considering the thickness change. However, according to actual experience, after the lens is installed on-site, the internal and external parameters of the camera basically do not change. Therefore, only the thickness change needs to be corrected. The thickness h in this system is given by a laser distance measuring device. The corrected pixel coordinates are as follows:

[0106]

[0107] Let g take z w = 0, and from the above formula, it can be deduced that: the plane coordinates x w 、y w of the points on the surface of the steel plate in the world coordinate system and the conversion relationship with the image pixel coordinates (u, v) of the image points formed by their projection are as follows:

[0108]

[0109] h When the CMOS area array camera detects the steel plate, the system starts measurement. At the same time, the speedometer records the walking length ΔS of the steel plate, and the laser distance measuring device records the current height ΔH. The data processing system starts to record and store the measured values ΔS and ΔH;

[0110] i According to the image detected by the CMOS area array camera, in each data scan cycle, the data processing system extracts the edge information of the image, and after thickness compensation, outputs the width W of the steel plate and the deviation value D of the steel plate from the center once.

[0111] j When the system takes the second image, the steel plate has traveled a distance of ΔS. The data processing system corrects the pixels of the previous image according to the pixel overlapping area between the second image and the previous image, and performs stitching calculation on the images;

[0112] k When ΔS in the system increases to 1000 mm, the data processing system corrects the data according to the historical images stored in the database, and refers to the national standard of the People's Republic of China ---- GB / T 709-2019 ---- Dimensions, shapes, weights and tolerances of hot-rolled steel plates and strips ---- the value A of the camber of every arbitrary 1000 mm steel plate ≤ actual length × 0.4%, and outputs the camber value. When the camber value exceeds the set threshold, the system gives an alarm prompt.

[0113]

[0114] When ΔS increases to the N + 1 scan cycle, the data processing system outputs the camber value according to the data from the 2nd to the N + 1st time. When the camber value exceeds the set threshold, the system gives an alarm prompt. And so on. When the tail of the entire steel plate passes through the system, the data recording of this roll is completed.

[0115] l According to the edge data of the steel plate during operation, the boundary value points at the head and tail of the plate strip are connected to calculate a straight line, and then the distance value of the edge value points of the entire steel plate deviates from this straight line is calculated, and then the sickle bend value of the entire steel plate is calculated and output. According to the settings, the data processing system gives a conclusion whether the sickle bend value of the steel plate meets the requirements: qualified (sickle bend value), unqualified (sickle bend value).

[0116] During the operation of the steel plate, the deviation value of the steel plate from the center can be transmitted to the control system of the rough rolling mill for closed-loop control.

[0117] When the steel plate is rolled in another direction, another set of measuring systems starts to work and continues to output data by referring to the above steps.

[0118] The main measurement concept of the present invention is: using a CMOS area array camera to accurately measure the length of the steel plate running, and then splicing the image, it can compensate for the displacement or twisting of the steel plate during operation. Using a laser thickness measuring device, it can accurately measure the edge position value even if the steel plate has warping and buckling, thereby providing accurate data for process control, improving the plate quality, and increasing the product yield rate.

[0119] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0120] In the description of the present application, it should be understood that the terms "middle", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present invention.

[0121] In addition, in the description of the present invention, “several” and “a plurality of” mean more than two, unless otherwise clearly and specifically defined.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered by the scope of the claims and the specification of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An online measuring system for camber of steel plates, comprising a mounting bracket arranged above a steel plate conveying roller path, wherein a mounting seat is arranged on the mounting bracket, and a measuring device is arranged on the mounting seat; Characterized in that, the measuring device is arranged in a heat insulation box, the heat insulation box is connected to an air cooling device, a dust-proof cover is arranged on one side of the heat insulation box facing the roller path, and when the air cooling device cools the measuring device, it is also used to open the dust-proof cover and provide positive pressure purging; Among them, the measuring method implemented by the online measuring system for camber of steel plates includes the following steps: Step 1, arrange a scanning device at the position of the center line of the unit directly above the roller path where the steel plate runs. The scanning device includes a CMOS area array camera, a laser velocimeter, and a laser rangefinder. Calculate the image acquisition frequency of the CMOS area array camera according to the real-time speed of the steel plate running and the field of view of the CMOS area array camera, and trigger the CMOS area array camera to acquire images; Step 2, when the head of the steel plate passes through the scanning device on the roller path, the data processing system detects the head of the steel plate, starts measurement and records data. The CMOS area array camera takes pictures of the running steel plate, and at the same time the laser velocimeter records the walking length ΔS of the steel plate; Step 3, the data processing system records the picture information in real time and stores the moving length ΔS of the steel plate; Step 4, according to the image detected by the CMOS area array camera, in each data scanning cycle, the data processing system corrects and outputs the steel plate width value and the value of the steel plate deviating from the center according to the steel plate thickness value output by the laser rangefinder; Step 5, when the second image is taken, the steel plate has traveled a distance of ΔS. The data processing system calculates the offset caused by the camber of the steel plate according to the pixel overlapping area part between the second image and the previous image, and corrects the pixels of the previous image. When ΔS increases to S≥1000mm, the data processing system outputs the camber data of the steel plate in the length of S according to the recorded picture information. When the camber value exceeds the set threshold, the data processing system gives an alarm prompt; Step 6, when it increases to the (N + 1)-th scanning cycle, N is a natural number greater than 1. The data processing system outputs the camber value according to the data from the 2nd to the (N + 1)-th time. When the camber value exceeds the set threshold, the system gives an alarm prompt, and so on. When the tail of the whole steel plate passes through the scanning device, the data recording of the steel plate is completed; Step 7, according to the edge data during the running of the steel plate, connect the boundary value points of the head and tail of the steel plate to calculate a straight line, and then calculate the distance value of the edge value points of the whole steel plate deviating from this straight line, and further calculate and output the camber value of the whole steel plate. And according to the setting, the data processing system gives a conclusion whether the camber value of the steel plate meets the requirements: qualified or unqualified.

2. The online measuring system for camber of steel plates according to claim 1, Characterized in that, the dust-proof cover is provided with a switching device, and the air cooling device opens the switching device through compressed air; The switch device is provided with an automatic reset mechanism. When the air cooling device stops delivering compressed air to the switch device, the automatic reset mechanism drives the switch device to close.

3. The online steel plate camber measurement system according to claim 1, characterized in that the heat insulation box is provided with a water cooling device.

4. The online steel plate camber measurement system according to claim 1, characterized in that the measuring device includes a laser velocimeter, a CMOS area array camera, and a laser rangefinder. The laser velocimeter, the CMOS area array camera, and the laser rangefinder are longitudinally arranged along the steel plate conveying direction and are perpendicular to the conveying plane of the roller table.

5. The online steel plate camber measurement system according to claim 4, characterized in that the CMOS area array camera is provided with a fixed-focus lens.

6. The online steel plate camber measurement system according to claim 1, characterized in that the measuring device is 2500 - 6000 mm away from the plane of the roller table.

7. The online steel plate camber measurement system according to claim 1, characterized in that the measuring device is electrically connected to a data processing system, and the data processing system is electrically connected to a display device and a rolling mill control system respectively.

8. The online steel plate camber measurement system according to claim 7, characterized in that data is transmitted between the measuring device and the data processing system through a gigabit network cable or an optical fiber.

9. The online steel plate camber measurement system according to any one of claims 1 - 8, characterized in that two sets of the mounting brackets, the mounting seats, and the measuring devices are respectively arranged on both sides of the rolling mill, and the two sets of measuring devices are respectively used for measuring steel plates rolled in different directions.

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