Device and method for measuring the profile of a steel sheet

Abstract

The application discloses a kind of steel plate profile measuring device and method, the device includes: laser speedometer measured real-time speed of steel plate to be measured is provided to PLC, sends first and second pulse signals;PLC obtains steel plate real-time integral displacement according to real-time speed, and sends second level signal according to displacement;According to the first level signal that light curtain detects loss condition is sent;First logic control unit obtains first control signal according to the and of first pulse signal and level signal;Second logic control unit obtains second control signal according to the and of second pulse signal and level signal;Second camera obtains steel plate head image according to second control signal photographing;First camera obtains steel plate middle tail image according to first control signal photographing;Image processing workstation is spliced to steel plate head and middle tail image, and steel plate profile data based on actual size is obtained by using cutting auxiliary line method to the pixel coordinate conversion of spliced image.This application can improve the measurement accuracy of steel plate profile.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel plate profile detection, and particularly relates to a steel plate profile measuring device and method. BACKGROUND

[0002] This section is intended to provide background or context to the application. The description herein does not constitute an admission that the information provided herein is prior art.

[0003] The main equipment of the heavy plate shearing line includes a head cutting shear, a double-sided shear and a sizing shear, which completes the head cutting, tail cutting, segmentation, edge cutting and sizing of the rolled steel plate, and is an important process for producing finished steel plates meeting the width and length requirements. Among them, the head cutting shear prepares for the subsequent continuous shearing by cutting the head, tail and segmenting (only for the sickle bend plate), which is the key link affecting the production efficiency, yield and automation level of the shearing line. If the control is improper, it may become a bottleneck of the production line.

[0004] Currently, during the shearing process of the head cutting shear, manual visual inspection combined with production experience is required to judge the length of the mother plate, the size of the side bend, the head cutting position and the tail cutting position, which can easily lead to short and rough segmentation errors, and there are problems such as under-shearing, over-shearing, high labor intensity of workers and low operation efficiency. Especially in the case of accelerated production rhythm, the problems are further aggravated. In addition, since the head cutting shear PLC control system cannot obtain the set data of head cutting, tail cutting and segmentation in advance, the head cutting shear cannot realize automatic shearing. In view of the problems existing in manual operation, although some manufacturers have tried to solve the problem by visual measurement, the measurement scheme (including measurement device and shearing calculation method) they use is still not perfect, and they have not considered the influence of objective factors such as variable plate speed, slipping and inertia in the process of heavy plate shearing on the profile measurement accuracy, and the measurement accuracy is also affected by relying on a single visual system to realize profile measurement, which leads to the inability to accurately measure the profile information of the steel plate. High-precision profile data is the premise and basis for optimizing shearing calculation and automatic shearing. Therefore, based on the practical needs of improving the production efficiency, yield and automation level of the head cutting shear, it is of strong urgency and application value to invent a heavy plate profile measuring device and calculation method with high measurement accuracy, strong real-time performance and strong environmental adaptability.

[0005] The on-site workers visually inspect the incoming steel plate profile, judge the length of the mother plate, the size of the side bend and the irregular length of the head and tail according to experience, and command the workers in the operation room to transport the steel plate to the shearing blade for shearing. Or the workers observe the irregular length of the head and tail according to experience through the video monitor in the operation room, and complete the shearing.

[0006] Relying on manual visual inspection and experience to determine the profile of the steel plate and the shearing position is prone to cause short length and rough division errors, and there are problems such as under-shearing, over-shearing, high labor intensity of workers, and low operation efficiency, especially in the case of accelerated production rhythm, the problems are further aggravated. At the same time, relying on pure manual observation and operation is also contrary to the development trend of automation and intelligentization of the current industry, and affects the enterprise image.

[0007] A line array camera is installed before the head cutting shear, and the profile of the steel plate is measured by combining the line array camera with the roller encoder. The encoder installed on the roller drive shaft measures the roller speed, and the pulse signal of the roller encoder is used to drive the line array camera to take pictures of the steel plate, and then the profile information of the steel plate is obtained by using image processing technology.

[0008] The line frequency of the line array camera must match the actual running speed of the steel plate, otherwise the problems of "frame repetition" and "frame loss" will occur, which will cause deviations between the steel plate image and the actual situation, and even errors. The existing technology two uses the pulse number of the roller encoder or the actual speed of the roller to replace the actual speed of the steel plate, which has the problem of mismatching the line frequency of the line array camera and the actual speed of the steel plate, which is reflected in the following two points: (1) The speed of the steel plate is not uniform during transportation to the head cutting shear, but varies, with acceleration and deceleration, and even start-stop. The single weight of a steel plate is 3-12 tons, so the steel plate is prone to slip and inertial motion during variable speed transportation. Once the slip and inertial motion occur, the pulse number of the roller encoder cannot reflect the actual speed of the steel plate. (2) The actual roller diameter changes with the wear of the roller, so the correspondence between the pulse number of the encoder and the actual running distance of the steel plate is also changing. Based on the above two points, the use of the pulse signal of the roller encoder to drive the line array camera for profile measurement in the existing technology two has uncertain errors in the actual production environment, and once the measurement error is large, the accuracy of the subsequent optimized shearing calculation based on the profile of the steel plate cannot be guaranteed. SUMMARY

[0009] The embodiment of the present application provides a kind of steel plate profile measurement device and method, to improve the measurement accuracy of steel plate profile, the device includes: light curtain, first line array camera, second line array camera, laser speed meter, first and gate logic control unit, second and gate logic control unit, PLC controller and image processing workstation, wherein:

[0010] The laser speed meter is located between the first linear array camera and the second linear array camera, is used for measuring the real-time speed of the steel plate to be measured, and provides the real-time speed to the PLC controller; the first pulse signal is provided to drive the first linear array camera to take a picture, and the second pulse signal is provided to drive the second linear array camera to take a picture; wherein the output frequency of the speed meter pulse signal changes with the running speed of the steel plate to be measured, and the speed meter sends a pulse signal every fixed pixel precision displacement of the steel plate running, so that the camera line frequency is matched with the running speed of the steel plate;

[0011] The PLC controller is used for obtaining the real-time integral displacement of the steel plate to be measured according to the real-time speed, and sending the second level control signal according to the real-time integral displacement of the steel plate to be measured; and sending the first level control signal according to the light curtain detection loss;

[0012] The first AND gate logic control unit is used for obtaining the first control signal by ANDing the first pulse signal and the first level control signal of the PLC, so as to control the first linear array camera to take a picture;

[0013] The second AND gate logic control unit is used for obtaining the first control signal by ANDing the second pulse signal and the second level control signal of the PLC, so as to control the second linear array camera to take a picture;

[0014] The second linear array camera is used for taking a picture according to the second control signal to obtain the head image of the steel plate to be measured;

[0015] The first linear array camera is used for taking a picture according to the first control signal to obtain the middle and tail images of the steel plate to be measured;

[0016] The image processing workstation is used for splicing, edge detection processing of the head image of the steel plate to be measured and the middle and tail images of the steel plate to be measured, obtaining the contour image of the steel plate to be measured, and performing pixel coordinate conversion and calculation on the contour image of the steel plate to be measured by using the cutting auxiliary line method, and finally obtaining the steel plate contour data based on the actual size.

[0017] The embodiment of the present application also provides a steel plate contour measurement method for improving the measurement precision of the steel plate contour, and the method comprises the following steps:

[0018] When it is detected that the head of the steel plate to be measured runs to the laser speed meter between the first linear array camera and the second linear array camera, the laser speed meter sends the first pulse signal and the second pulse signal, and the first level control signal and the second level control signal of the PLC controller are both high level signals;

[0019] The first AND gate logic control unit outputs a first control signal by ANDing a first pulse signal and a high level signal, and the second AND gate logic control unit outputs a second control signal by ANDing a second pulse signal and the high level signal, so as to control the first line array camera and the second line array camera to start photographing at the same time, and the PLC controller starts real-time displacement integration to obtain real-time integral displacement of the steel plate to be measured; wherein the output frequency of the tachometer pulse signal changes with the running speed of the steel plate to be measured, and the tachometer outputs a pulse signal every time the steel plate runs a fixed pixel precision displacement, so that the camera line frequency is matched with the running speed of the steel plate;

[0020] When it is detected that the real-time integral displacement of the steel plate to be measured reaches the distance between the first line array camera and the second line array camera, the PLC controller stops integration, and the second level control signal output by the PLC controller is a second low level signal;

[0021] The second AND gate logic control unit outputs the second control signal by ANDing the second pulse signal and the second low level signal, so as to control the second line array camera to stop photographing and obtain the head image of the steel plate to be measured;

[0022] When the light curtain detects the steel plate to be measured before the laser tachometer, the first level control signal output by the PLC controller is a first low level signal;

[0023] The first AND gate logic control unit outputs the first control signal by ANDing the first pulse signal and the first low level signal, so as to control the first line array camera to stop photographing and obtain the middle and tail images of the steel plate to be measured;

[0024] The image processing workstation performs splicing and edge detection processing on the head image of the steel plate to be measured and the middle and tail images of the steel plate to be measured, to obtain a contour image of the steel plate to be measured; and the contour image of the steel plate to be measured is subjected to pixel-by-pixel coordinate conversion and calculation by using a cutting auxiliary line method, to finally obtain steel plate contour data based on actual size.

[0025] The embodiment of the present application also provides a computer device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the above-mentioned steel plate contour measurement method when executing the computer program.

[0026] The embodiment of the present application also provides a computer readable storage medium, which stores a computer program, and the computer program implements the above-mentioned steel plate contour measurement method when executed by a processor.

[0027] The embodiment of the present application also provides a computer program product, which comprises a computer program, and the computer program implements the above-mentioned steel plate contour measurement method when executed by a processor.

[0028] The beneficial technical effects of the steel plate profile measurement scheme provided by the embodiment of the present application are as follows: first, the laser speed meter is used to measure the real-time speed of the steel plate or the real-time pulse signal corresponding to the speed of the steel plate in the whole process of measuring the profile of the steel plate, instead of the speed of the roller or the pulse signal of the roller encoder, so that the line frequency of the line array camera can be matched with the actual speed of the steel plate, and thus the accurate acquisition of the image frame of the steel plate can be realized; second, the embodiment of the present application adopts the structure of two rows of line array cameras (the first line array camera and the second line array camera) + a laser speed meter, and the laser speed meter is arranged between the two rows of cameras, so that the cameras can always work under the control of the laser speed meter, and the influence of the "speed measurement blind area" on the profile measurement accuracy can be avoided; third, the embodiment of the present application is provided with an AND gate logic control unit (the first AND gate logic control unit and the second AND gate logic control unit), which can flexibly control the start and stop of the line array camera online, and cooperate with the real-time displacement integration of the PLC to accurately control the working window of the two rows of cameras, and realize the independent measurement of the "head" profile and the "middle + tail" profile of the steel plate; fourth, the actual size coordinates of each pixel point on the profile of the steel plate are quickly calculated through the cutting auxiliary line method for pixel coordinate conversion and calculation, and the profile data of the steel plate based on the actual size are finally obtained, and the calculation response of the method is fast and the calculation accuracy meets the process and production requirements. In summary, the present application can improve the measurement accuracy of the profile of the steel plate. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort. In the drawings:

[0030] Figure 1 It is a structural schematic diagram of the steel plate profile measurement device in the embodiment of the present application;

[0031] Figure 2 It is a structural schematic diagram of the steel plate profile measurement device in another embodiment of the present application;

[0032] Figure 3 It is a schematic diagram of the line light source irradiation range in the embodiment of the present application;

[0033] Figure 4 It is a schematic diagram of the AND gate logic control unit in the embodiment of the present application;

[0034] Figure 5 It is a schematic diagram of the PLC integral control in the embodiment of the present application;

[0035] Figure 6 It is a flow schematic diagram of the steel plate profile measurement method in another embodiment of the present application;

[0036] Figure 7 Fig. 1 is a schematic diagram of a rail head profile image in an embodiment of the present application;

[0037] Figure 8 Fig. 2 is a schematic diagram of a rail middle and tail profile image in an embodiment of the present application;

[0038] Figure 9 Fig. 3 is a schematic diagram of a spliced image (including a roller edge) in an embodiment of the present application;

[0039] Figure 10 Fig. 4 is a schematic diagram of an extracted steel plate image (including a roller edge) in an embodiment of the present application;

[0040] Figure 11 Fig. 5 is a schematic diagram of a calibration plate measurement in an embodiment of the present application;

[0041] Figure 12 Fig. 6 is a schematic diagram of a WMapT construction process in an embodiment of the present application;

[0042] Figure 13 Fig. 7 is a schematic diagram of an LDcor construction process in an embodiment of the present application;

[0043] Figure 14 Fig. 8 is a schematic diagram of a cutting auxiliary line method in an embodiment of the present application;

[0044] Figure 15 Fig. 9 is a schematic diagram of a steel plate profile measurement method flowchart in an embodiment of the present application. DETAILED DESCRIPTION

[0045] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, further detailed description of the embodiments of the present application will be given below with reference to the drawings. Herein, the schematic embodiments of the present application and their descriptions are used to explain the present application, but not to limit the present application.

[0046] In the technical solutions of the present application, the acquisition, storage, use, processing, etc. of data all comply with relevant provisions of laws and regulations.

[0047] In view of the technical problems existing in the profile measurement of the existing steel plate, the profile measurement scheme of the steel plate in the embodiment of the present application is a profile measurement scheme of a thick plate, which is a profile measurement scheme of a thick plate based on a linear array camera and a laser speed measuring instrument. The scheme optimizes and improves the problems existing in the prior art from the following aspects: first, the real-time speed of the steel plate measured by the laser speed measuring instrument or the real-time pulse signal corresponding to the speed of the steel plate is used instead of the speed of the roller or the pulse signal of the roller encoder in the whole process of measuring the profile of the steel plate. In this way, the line frequency of the linear array camera can be matched with the actual speed of the steel plate, so that the accurate acquisition of the image frame of the steel plate can be realized. Second, the measuring device adopts the structure of two rows of linear array cameras + a laser speed measuring instrument, and the laser speed measuring instrument is arranged between the two rows of cameras. In this way, the cameras can always work under the control of the laser speed measuring instrument, and the influence of the "speed measuring blind area" on the profile measurement accuracy can be avoided. Third, the measuring device is provided with an AND gate logic control unit, which can flexibly control the start and stop of the linear array camera online, and cooperate with the real-time displacement integration of the PLC to accurately control the working window of the two rows of cameras, so that the independent measurement of the "head" profile and the "middle + tail" profile of the steel plate can be realized. Fourth, the actual size coordinates of each pixel point on the profile of the steel plate are quickly calculated through the cutting auxiliary line method for pixel coordinate conversion and calculation, and the profile drawing of the steel plate based on the actual size can be drawn. The calculation response of the method is fast, and the calculation accuracy meets the process and production requirements. The profile measurement scheme of the steel plate will be described in detail below.

[0048] Figure 1 The structure diagram of the measuring device for the profile of the steel plate in the embodiment of the present application is shown in Figure 1 , which comprises: a light curtain, a first linear array camera, a second linear array camera, a laser speed measuring instrument, a first AND gate logic control unit, a second AND gate logic control unit, a PLC controller and an image processing workstation, wherein:

[0049] The laser speed measuring instrument is located between the first linear array camera and the second linear array camera, and is used for measuring the real-time speed of the steel plate to be measured and providing the real-time speed to the PLC controller. The laser speed measuring instrument provides a first pulse signal to drive the first linear array camera to take a picture, and provides a second pulse signal to drive the second linear array camera to take a picture. The output frequency of the pulse signal of the speed measuring instrument changes with the running speed of the steel plate to be measured. The speed measuring instrument sends out a pulse signal for each fixed pixel precision displacement of the steel plate, so that the line frequency of the camera matches the running speed of the steel plate.

[0050] The PLC controller is used for obtaining the real-time integral displacement of the steel plate to be measured according to the real-time speed, and sending out a second level control signal according to the real-time integral displacement of the steel plate to be measured. The PLC controller sends out a first level control signal according to the light curtain detection loss.

[0051] A first AND gate logic control unit is configured to obtain a first control signal by ANDing the first pulse signal and a first level control signal of the PLC, so as to control the first linear array camera to take a picture;

[0052] A second AND gate logic control unit is configured to obtain a first control signal by ANDing the second pulse signal and a second level control signal of the PLC, so as to control the second linear array camera to take a picture;

[0053] The second linear array camera is configured to take a picture according to the second control signal to obtain a head image of the steel plate to be measured;

[0054] The first linear array camera is configured to take a picture according to the first control signal to obtain a middle and tail image of the steel plate to be measured;

[0055] The image processing workstation is configured to splice and perform edge detection processing on the head image of the steel plate to be measured and the middle and tail image of the steel plate to be measured, to obtain a contour image of the steel plate to be measured, and to perform pixel-by-pixel coordinate conversion and calculation on the contour image of the steel plate to be measured by using a cutting auxiliary line method, so as to finally obtain steel plate contour data based on actual size.

[0056] The steel plate contour measurement device provided by the embodiment of the present application has the following beneficial technical effects: first, in the whole process of measuring the steel plate contour, the laser speed measuring instrument measures the real-time speed of the steel plate or the real-time pulse signal corresponding to the speed of the steel plate, rather than the speed of the roller or the pulse signal of the roller encoder, so that the line frequency of the linear array camera can be matched with the actual speed of the steel plate, and thus the accurate acquisition of the steel plate image frame can be realized; second, the embodiment of the present application adopts the structure of two rows of linear array cameras (the first linear array camera and the second linear array camera) + the laser speed measuring instrument, and the laser speed measuring instrument is arranged between the two rows of cameras, so that the cameras can always work under the control of the laser speed measuring instrument, and the influence of the "speed measurement blind area" on the contour measurement accuracy can be avoided; third, the embodiment of the present application is provided with the AND gate logic control unit (the first AND gate logic control unit and the second AND gate logic control unit), which can flexibly control the start and stop of the linear array camera online, and can cooperate with the real-time displacement integration of the PLC to accurately control the working window of the two rows of cameras, so as to realize the independent measurement of the "head" contour and the "middle + tail" contour of the steel plate; fourth, the pixel-by-pixel coordinate conversion and calculation are performed by using the cutting auxiliary line method, the actual size coordinates of each pixel point on the steel plate contour are quickly calculated, and finally the steel plate contour data based on actual size is obtained, and the calculation response of the method is fast and the calculation accuracy meets the process and production requirements. In summary, the present application can improve the measurement accuracy of the steel plate contour. The following will be described in detail.

[0057] The embodiment of the present application proposes a thick plate profile measurement device based on a linear array camera and a laser speed meter and a profile data calculation method. A gantry is erected before a head cutting shear, and a linear array camera, a laser speed meter, a light curtain and other devices are installed on the gantry. The laser speed meter feeds back the real-time speed of the steel plate. The linear array camera takes pictures under the control of the non-fixed frequency pulse signal of the laser speed meter, and cooperates with the real-time displacement integration of the PLC to accurately obtain each frame of image in the running process of the steel plate. Then, the profile image of the steel plate is obtained by comprehensively applying image processing technology, and the data features of the actual size of the steel plate are obtained after pixel-by-pixel coordinate conversion and calculation of the profile image. The profile data based on the actual size is the basis for optimizing the cutting calculation of the thick plate and can also support the automatic cutting of the head cutting shear.

[0058] The thick plate profile measurement device based on the linear array camera is composed of a profile measurement module and a profile post calculation module, as shown in Figure 1 The profile measurement module can include two linear array cameras, a high-brightness linear LED light source, a laser speed meter, a light curtain, a pulse distributor, two sets of logic control units and a PLC. The linear array camera, the light source, the laser speed meter and the light curtain are installed on the gantry before the head cutting shear, and the pulse distributor, the logic control unit and the PLC are placed in the electrical cabinet. In one embodiment, the first linear array camera, the second linear array camera, the laser speed meter and the light curtain are installed on the gantry before the head cutting shear, and the first AND gate logic control unit, the second AND gate logic control unit and the PLC controller are placed in the electrical cabinet. The profile post calculation module can include an image processing workstation and a profile calculation algorithm, wherein the profile calculation algorithm runs in the image processing workstation.

[0059] 1. Specific configuration and function description of the profile measurement module

[0060] (1) Linear array camera

[0061] As shown in Figure 1 and Figure 2 , two cameras (the first linear array camera and the second linear array camera) can adopt high-resolution and high-line-frequency linear array cameras, are installed directly above the center line of the roller, are arranged before and after the running direction of the steel plate, are separated by D1 meters, are away from the roller by H1 meters, and D1 should be greater than the shortest steel plate length of the steel plate and the possible maximum head irregular length. As shown in Figure 2 , a suitable lens focal length is selected according to the installation height H1, so that the field of view of the camera covers the roller width RTW (including the edges of the roller).

[0062] According to the resolution of the linear array camera LCR and the width of the roller table RTW, the pixel accuracy PixL can be calculated according to the following formula (1), which needs to meet the accuracy requirement of the profile measurement, or the required camera resolution LCR can be determined according to the required pixel accuracy PixL according to the following formula (2). If higher pixel accuracy or wider steel plate is required, multiple cameras can be arranged in the width direction to ensure the measurement accuracy of the profile in the width direction of the steel plate.

[0063] PixL = RTW / LCR (1)

[0064] LCR = RTW / PixL (2)

[0065] According to the maximum running speed Vmax of the steel plate and the pixel accuracy PixL, the required maximum line frequency LFmax of the camera can be determined according to the following formula (3). In actual use, the camera takes a picture under the control of the output pulse signal of the laser speedometer, that is, each high-level signal triggers the camera to take a picture once. Since the speed Vi of the steel plate is variable, the working line frequency LFi of the camera (which can be obtained according to the following formula (4)) is also dynamic.

[0066] LFmax = Vmax / PixL (3)

[0067] LFi = Vi / PixL (4)

[0068] From the above, in one embodiment, the camera line frequency of the above-mentioned steel plate profile measurement device can also be calculated according to the following formula:

[0069] LFi = Vi / PixL;

[0070] Wherein, PixL = RTW / LCR; LFi is the line frequency of the camera, Vi is the real-time speed of the steel plate, PixL is the pixel accuracy, RTW is the width of the roller table, and LCR is the resolution of the camera.

[0071] The camera light source uses a high-brightness strip LED light source, and the irradiation line is between the two roller tables, covering the entire roller table (including the edges of the two roller tables), as shown in Figure 3 to ensure that the camera can clearly capture the steel plate and the edges of the roller table, and the installation height H is 3 meters. That is, in one embodiment, the above-mentioned steel plate profile measurement device can further include: a linear LED light source for providing a light source required for steel plate profile measurement. The linear array camera can use a special protective cover, and the cover is cooled and cleaned by compressed air to ensure that the camera can operate stably for a long time.

[0072] In the embodiment of the present application, the roller width can be 2800mm, the maximum width of the steel plate can be 2500mm, the maximum running speed of the steel plate can be 2m / s, the pixel accuracy can be ≤2mm, the determined line array camera resolution can be 4K, the line frequency can be no less than 4000Hz, and the actual pixel accuracy can be 1.4mm. The installation spacing D1 of the two line array cameras on the gantry can be 1.6m, the installation height H1 can be 2m, the lens focal length can be 51.2mm, the width of the strip-shaped LED line light source can be 2810mm, and the installation height H3 can be 0.8m.

[0073] (2) Laser speed meter

[0074] The laser speed meter feeds back the real-time speed of the steel plate and drives the line array camera to take pictures with a non-fixed frequency pulse signal, and the real-time speed is provided to the PLC for high-precision displacement integration. In the embodiment of the present application, the laser speed meter is used instead of the roller encoder, which can ensure that the running speed of the steel plate can be accurately measured under any running condition of the steel plate (whether slipping or inertia), and further ensure that the actual line frequency of the line array camera matches the running speed of the steel plate, avoiding the phenomena of “frame repetition” and “frame loss”. The two line array cameras arranged before and after the running direction of the steel plate cooperate with the laser speed meter to avoid the “speed measurement blind area” of the steel plate. Therefore, the arrangement mode of “line array camera + laser speed meter + line array camera” can maximize the accuracy of image frame acquisition from the measurement hardware level. The laser speed meter is installed on the gantry between the two line array cameras, 2m away from the 1# line array camera and 1.5m high, as shown in FIG. 2. Figure 2

[0075] The output frequency PFi of the laser speed meter pulse signal is non-fixed, so that a pulse signal is output every fixed pixel accuracy PixL when the steel plate runs, and PFi changes accordingly when the speed of the steel plate changes, and PFi is consistent with the line frequency LFi of the camera, which can be calculated according to formula 5.

[0076] PFi=LFi=Vi / PixL(5)

[0077] In the embodiment of the present application, preferably, the laser speed meter is 0.6m away from the 1# line array camera (first line array camera) and 1.5m high. The main parameters of the laser speed meter can be as shown in Table 1.

[0078] Table 1:

[0079] Parameter Technical index Measurement depth of field 200mm Measurement range ±20000m / min Measurement accuracy ≥0.07%(center of depth of field ±50mm, ≥0.03%) Repeatability Better than 0.02% Measurement acceleration range ≥ 500 m / s 2 ]] Sampling refresh rate ＞100000 / s Protection level IP67

[0080] (3) Light curtain

[0081] ​The light curtain can be installed in an up-down manner, and can be installed on both sides of the roller by using a special bracket. The installation height of the light curtain above the roller is H4 meters, and is located between the laser speed meter and the 1# line array camera, and is D3 meters away from the 1# line array camera, as shown in Figure 2 .

[0082] In the embodiment of the present application, the light curtain can be a reflection type, the optical axis spacing can be 10 mm, the number of optical axes can be 400, and the protection level can be IP65.

[0083] (4) Pulse distributor

[0084] The pulse distributor expands the pulse signal of the laser speed meter, and converts the 1-way pulse signal into 2-way pulse signals for output, as shown in Figure 1 . That is, in one embodiment, the above-mentioned steel plate profile measuring device can further include: a pulse distributor, configured to expand the pulse signal of the laser speed meter, and convert the 1-way pulse signal into the first pulse signal and the second pulse signal for output.

[0085] (5) Logic control unit

[0086] In the embodiment of the present application, an AND gate logic control unit (first AND gate logic control unit and second AND gate logic control unit) is arranged in the measuring device to achieve flexible control of the line array camera. The AND gate logic control unit is ANDed with the pulse signal of the laser speed meter and the control signal of the PLC to achieve, as shown in Figure 4 .

[0087] Specifically, when the control signal of the PLC is high, the camera is only controlled by the pulse signal of the laser speed meter. When the real-time integral displacement of the PLC reaches D1, the PLC gives a low-level signal, which can shield the control of the laser speed meter on the 2# camera, so that the 2# camera stops shooting. When the light curtain is lost, the PLC gives a low-level signal to shield the control of the laser speed meter on the 1# camera, so that the 1# camera stops shooting.

[0088] That is, in one embodiment, the above-mentioned PLC controller is specifically used for: when the real-time integral displacement of the steel plate to be measured reaches D1 (the distance between the first line array camera and the second line array camera), the second level control signal emitted is a second low-level signal (such as LS2 in Figure 6 ), and the second low-level signal is ANDed with the second pulse signal emitted by the laser speed meter to obtain a second control signal to control the second line array camera to stop shooting, that is, the control of the laser speed meter on the 2# camera (the second line array camera) is shielded, so that the 2# camera stops shooting; when the light curtain is lost, the first level control signal emitted is a first low-level signal (such as LS1 in Figure 6The first low-level signal is used to control the first linear array camera to stop shooting by being combined with the first pulse signal from the laser speedometer, that is, the control of the laser speedometer on the 1# camera (the first linear array camera) is shielded, and the 1# camera stops shooting.

[0089] (6) PLC controller

[0090] The measurement device separately measures the 'head' profile and the'middle + tail' profile of the steel plate, wherein the 'head' profile is photographed by the 2# linear array camera, and the process needs to be matched with the real-time displacement integration of the PLC, and the PLC controls the end of the photographing of the 2# camera according to the integrated displacement, as shown in the formula: Displacement integration = (Real-time speed of laser speedometer) * (100ms). Figure 5 The PLC performs displacement integration at a time interval of 100ms, and the displacement calculation is high in accuracy and fast in speed, so that the accurate measurement of the 'head' profile of the steel plate by the camera can be accurately controlled.

[0091] In the embodiment of the application, preferably, the measurement device can share the four-gate S7-400 PLC controller of the basic automatic control system of the head cutting shear area.

[0092] 2. Specific configuration and function description of the profile post-computation module

[0093] (1) Image processing workstation

[0094] The image processing workstation can be connected with the linear array camera through a gigabit network cable, receive the output image of the camera, and process the image by running a profile computation algorithm, and the main technical parameters are shown in Table 2.

[0095] Table 2:

[0096] Name Technical parameters Processor Intel Core I7-11700 Memory 16G Hard disk 2T Graphics card RTX3060Ti 8G Network card 2×4-port gigabit

[0097] (2) Profile computation algorithm

[0098] The profile computation algorithm processes the steel plate image output by the profile measurement module, such as splicing and edge detection, to obtain the profile image of the thick plate, and performs pixel-by-pixel coordinate conversion and computation by using the cutting auxiliary line method, so as to finally obtain the steel plate profile data and profile graph based on the actual size.

[0099] Measurement logic

[0100] In the thick plate profile measurement process, the two linear array cameras are controlled by the pulse signal of the laser speedometer in a hard trigger mode, the PLC performs real-time displacement integration (scanning period: 100ms) according to the real-time speed of the laser speedometer, and sends a control signal according to the integrated displacement, and the camera is controlled to start shooting or stop shooting after the pulse signal and the control signal are operated by the AND logic control unit, and the specific measurement logic is shown in the formula: Figure 6 ​

[0101] The measurement step of the thick plate profile measurement device is as follows:

[0102] (1) Before starting measurement, the control signal of the PLC is high level, and the laser speedometer has no pulse signal.

[0103] (2) When the head of the steel plate runs to the laser speedometer between the line array cameras, the speedometer sends out a pulse signal (first pulse signal and second pulse signal), at this time the control signal of the PLC is still high level (both the first level control signal and the second level control signal are high level signals), the 1# and 2# line array cameras (the first line array camera and the second line array camera) start photographing at the same time. At the same time, the PLC starts real-time displacement integration, and the displacement of the steel plate is Si. The output frequency of the speedometer pulse signal changes with the running speed of the steel plate, and a pulse signal is sent out for every fixed pixel precision PixL displacement of the steel plate, so that the camera line frequency matches the running speed of the steel plate.

[0104] (3) When the integrated displacement Si of the PLC reaches the camera interval D1, the PLC stops integration, as shown in Figure 5 , and outputs a low level control signal LS2 (the second level control signal LS2 sent out by the PLC controller is the second low level signal), the second pulse signal is shielded after passing through the second AND gate logic control unit, the second camera stops photographing, and outputs the "head" profile image ImgPfl2 of the steel plate, and the first camera continues to photograph. The image ImgPfl2 includes the invalid part before the steel plate reaches the 2# camera, as shown in Figure 7 .

[0105] (4) When the light curtain before the speedometer detects the loss of the steel plate, the PLC outputs a low level control signal LS1 (the first level control signal is the first low level signal), and the first pulse signal is shielded after passing through the first AND gate logic control unit (the first pulse signal of the speedometer), the first camera stops photographing, and outputs the "middle + tail" profile image ImgPfl1 of the steel plate. The image ImgPfl1 includes the invalid part after the tail of the steel plate leaves the 1# camera, as shown in Figure 8 .

[0106] (5) The image processing algorithm is used to splice the image ImgPfl2 and the image ImgPfl1 to obtain the overall profile image of the steel plate.

[0107] Actual profile calculation method

[0108] After the profile calculation algorithm receives the "head" profile image ImgPfl2 and the "middle+tail" profile image ImgPfl1 output by the profile measurement module, the two images can be spliced and edge detected, and the splicing accuracy can reach 1-2 pixel accuracy, and then the profile calculation method of the application is used to convert the size of the profile and calculate it. The image splicing and edge detection process will not be described in detail in the embodiment of the application, and only the size conversion and calculation process of the profile image after splicing and edge detection will be described.

[0109] In the embodiment of the application, the splicing accuracy of the steel plate image can be <3mm, and the spliced steel plate image is as shown in Figure 9 Further to Figure 9 The non-steel plate body part is removed using edge detection, threshold segmentation and connected domain analysis, including the invalid part before the head profile, the invalid part after the tail profile and the invalid part on both sides of the steel plate, and only the steel plate profile and the roller edge line are reserved, as shown in Figure 10 .

[0110] The extracted profile image is based on the image coordinate system, and its geometric size is not the actual size of the steel plate. The image size needs to be converted into the actual size, and the specific steps are as follows:

[0111] (1) Construct the width size mapping table WMapT and the length distortion factor LDcor

[0112] The profile measurement device is used to measure special calibration plates of different thicknesses, and the calibration plates adopt a chessboard pattern. In the application, the size of the calibration plate is 2800mmx400mm, the size of each black / white square on the plate is 80mmx80mm, and there are 8 thicknesses (12, 16, 20, 25, 30, 35, 40, 45), as shown in Figure 11 The calibration plate is placed on the roller, and at the same time, the calibration plate is tightly attached to the edge of one side of the roller. The calibration plate passes under the line array camera at a certain fixed speed, and the camera takes a picture of the steel plate under the control of the output signal of the door logic control unit, and obtains the image of the calibration plate after image processing. The image also includes the edge lines on both sides of the roller.

[0113] Based on the calibration plate image, the mapping table for width conversion and the distortion factor for length are determined respectively.

[0114] Take any column of the calibration board image and perform calibration and calculations on that column. Using the edge line on one side of the roller conveyor as the baseline, measure the pixel distance WPi from the top left corner of each black cell in that column to the baseline using the Halcon algorithm. The actual distance Wi from the top left corner of the black cell to the baseline is known (because the size of each cell in the calibration board is known, and the calibration board is in close contact with the baseline). Therefore, multiple sets of (WPi, Wi) data can be obtained, such as... Figure 12 As shown in Table 3, this data is the mapping table WMapT (a mapping table of image size and actual size for different steel plate thicknesses corresponding to the conversion of steel plate width to the actual size) of the thickness calibration plate in the direction of roller width or steel plate width under the current measuring device.

[0115] Table 3: Examples of WMapT data for different thicknesses

[0116] 8mm 16mm 20mm 25mm 30mm 35mm 40mm 45mm (WP1,W1)8 (WP1,W1) 16 ]]> (WP1,W1) 20 ]]> (WP1,W1) 25 ]] (WP1,W1) 30 ]] (WP1,W1) 35 ]]> (WP1,W1) 40 ]]> (WP1,W1) 45 <!-- 9 -->]]> (WP2, W2)8 (WP2, W2) 16 ]] (WP2, W2) 20 ]] (WP2, W2) 25 ]]> (WP2, W2) 30 ]]> (WP2, W2) 35 ]] (WP2, W2) 40 ]] (WP2, W2) 45 ]] … … … … … … … … (WP i ,W i )8]]> (WP i ,W i ) 16 ]]> (WP i , i ) 20 ]]> (WP i ,W i ) 25 ]]> (WP i , i ) 30 ]]> (WP i ,W i ) 35 ]]> (WP i ,W i ) 40 ]]> (WP i ,W i ) 45 ]]> … … … … … … … … (WP 34 ,W 34 )8]]> (WP 34 ,W 34 ) 16 ]]> (WP 34 ,W 34 ) 20 ]]> (WP 34 ,W 34 ) 25 ]]> (WP 34 ,W 34 ) 30 ]]> (WP 34 ,W 34 ) 35 ]]> (WP 34 ,W 34 ) 40 ]]> (WP 34 ,W 34 ) 45 ]]> (WP 35 ,W 35 )8]]> (WP 35 ,W 35 ) 16 ]]> (WP 35 , 35 ) 20 ]]> (WP 35 ,W 35 ) 25 ]]> (WP 35 ,W 35 ) 30 ]]> (WP 35 , 35 ) 35 ]]> (WP 35 , 35 ) 40 ]]> (WP 35 ,W 35 ) 45 ]]>

[0117] The distortion level of each frame of the linear scan camera is the same in the running direction or length direction of the steel plate, but the distortion differs in the width direction of the roller conveyor or the width direction of the steel plate. Therefore, it is necessary to construct a length distortion factor along the width direction, which varies with the pixel distance WPi. Taking the edge line on one side of the roller conveyor as the baseline, the pixel distance WPi from the top left corner of each black cell in the column to the baseline is measured using the Halcon algorithm, as well as the length LPi of the top edge (the edge containing the top left corner) of each black cell in the image. The actual length Li of the top edge of the black cell is known (because the size of each cell in the calibration plate is known), such as... Figure 13 As shown, the length distortion factor LDcori at the width pixel distance WPi can be calculated using formula (6). The length distortion factor LDcor of the thickness calibration plate in the width direction of the roller conveyor or the width direction of the steel plate under the current measuring device (the table of length distortion factors corresponding to different steel plate thicknesses) is shown in Table 4 below.

[0118] LDcori=LPi / L (6)

[0119] Table 4: Examples of LDcor data for different thicknesses

[0120] Pixel distance 12mm 16mm 20mm 25mm 30mm 35mm 40mm 45mm ​ LDcor1 12 ]]> LDcor1 16 ]]> LDcor1 20 ]]> LDcor1 25 ]]> LDcor1 30 ]]> LDcor1 35 ]]> LDcor1 40 ]]> LDcor1 45 ]]> ​ LDcor2 12 ]]> LDcor2 16 ]]> LDcor2 20 ]]> LDcor2 25 ]]> LDcor2 30 ]]> LDcor2 35 ]]> LDcor2 40 ]] LDcor2 45 ]]> … … … … … … … … WP i ]]> LDcori 12 ]]> LDcori 16 ]]> LDcori 20 ]]> LDcori 25 ]]> LDcori 30 ]]> LDcori 35 ]]> LDcori 40 ]]> LDcori 45 ]]> … … … … … … … … WP 34 ]] LDcor34 12 ]]> LDcor34 16 ]]> LDcor34 20 ]]> LDcor34 25 ]]> LDcor34 30 ]]> LDcor34 35 ]]> LDcor34 40 ]]> LDcor34 45 ]]> WP 35 ]] LDcor35 12 ]]> LDcor35 16 ]]> LDcor35 20 ]]> LDcor35 25 ]]> LDcor35 30 ]]> LDcor35 35 ]]> LDcor35 40 ]]> LDcor35 45 ]]>

[0121] If the camera installation height and camera parameters change, WMapT and LDcor need to be rebuilt.

[0122] (2) Steel plate contour coordinate transformation and calculation

[0123] For example Figure 10 The actual outline of the steel plate shown is converted from the image size of each point on the steel plate outline to its actual size using the cutting auxiliary line method. The steps are as follows:

[0124] 1) Adopting cutting auxiliary line, cut the steel plate contour image from the leftmost end of the contour (coordinate 0) with a step of one pixel length, and calculate all intersection points P of the cutting auxiliary line and the contour by Halcon algorithm. i1 (Ri1,Ci1),..., P ij (Rij,Cij),..., Pi n (Rin,Cin) and the intersection point P of the lower edge line of the roller. i0 (Ri0,Ci0), as Figure 14 shown, until there is no intersection point between the cutting line and the contour.

[0125] 2) For the i-th cutting, calculate the distance WPij between each intersection point P ij (Rij,Cij) and the lower edge line of the roller in the width direction by formula (7). At the same time, calculate the pixel number NLPi of each intersection point P ij (Rij,Cij) from the leftmost end reference line of the contour (i.e., the line passing through coordinate 0), and the pixel number of all intersection points on the same cutting line from the leftmost end of the contour is the same.

[0126] WPij(i,j) = Rij - Ri0 (7)

[0127] where i represents the number of cutting, j represents the number of intersection points, R i0 represents the vertical coordinate of the intersection point of the cutting line and the lower edge line of the roller, R ij represents the vertical coordinate of the j-th intersection point of the cutting line and the contour.

[0128] NLPi(i) = i (8)

[0129] where i represents the number of cutting.

[0130] 3) Based on the mapping data in the WMapT table, the WPij of each intersection point is calculated by interpolation to obtain the actual length Wij of each intersection point from the lower edge of the roller.

[0131] Based on the distortion factor data in the LDcor table, the WPij of each intersection point is calculated by interpolation to obtain the length distortion factor LDcorij of each intersection point in the width direction. Then, the actual length Lij of each intersection point from the leftmost end reference line of the contour is calculated by formula (9).

[0132] Lij = NLPixPixL x LDcorij (9)

[0133] wherein NLPi represents the number of pixels from the reference line at the left end of the profile, PixL represents the pixel accuracy, and LDcorij represents the length distortion factor.

[0134] 4) Through the whole cutting process, the image size / coordinate of each pixel on the profile image can be finally converted into the actual size / coordinate, i.e. (Rij, Cij)→(Wij, Lij), which is based on the lower edge line of the roller and the reference line at the left end of the profile. Thus, the data features of the steel plate profile are obtained.

[0135] 5) The actual size / coordinate of the steel plate is used as the input data for the optimization of the cutting system for further calculation. Meanwhile, since the actual width coordinate of the steel plate profile is relative to the lower edge line of the roller, the calculated data of the steel plate profile can also reflect the actual camber degree of the steel plate.

[0136] From the above, in one embodiment, the profile image of the steel plate to be measured is converted and calculated pixel by pixel based on the cutting auxiliary line method, and the profile data of the steel plate based on the actual size is finally obtained, which can include:

[0137] mapping tables of the image size and the actual size corresponding to the steel plate width conversion for different steel plate thicknesses, and distortion factor tables for the length corresponding to different steel plate thicknesses;

[0138] According to the mapping tables of the image size and the actual size corresponding to the steel plate width conversion for different steel plate thicknesses, and the distortion factor tables for the length corresponding to different steel plate thicknesses, the image size of each point on the profile image of the steel plate to be measured is converted into the actual size by using the cutting auxiliary line method, and the profile data of the steel plate based on the actual size is finally obtained.

[0139] From the above, in one embodiment, according to the mapping tables of the image size and the actual size corresponding to the steel plate width conversion for different steel plate thicknesses, and the distortion factor tables for the length corresponding to different steel plate thicknesses, the image size of each point on the profile image of the steel plate to be measured is converted into the actual size by using the cutting auxiliary line method, and the profile data of the steel plate based on the actual size is finally obtained, which can include:

[0140] The profile image of the steel plate is cut pixel by pixel from the left end of the profile by using the cutting auxiliary line with a step length of one pixel, and all the intersection points of the cutting auxiliary line and the profile of the steel plate and the intersection points of the cutting auxiliary line and the lower edge line of the roller are calculated, until there is no intersection point of the cutting auxiliary line and the profile of the steel plate.

[0141] For each cutting, the distance of each intersection point from the lower edge line of the roller in the width direction is calculated, and the number of pixels of each intersection point from the reference line at the left end of the profile is calculated.

[0142] Based on the mapping data in the mapping table corresponding to the image size converted for the steel plate width and the actual size of different steel plate thicknesses, the distance of each intersection point from the lower edge line of the roller in the width direction is calculated by interpolation, and the actual length of each intersection point from the lower edge of the roller is obtained;

[0143] Based on the distortion factor data in the distortion factor table corresponding to the length of different steel plate thicknesses, the horizontal coordinate of each intersection point is calculated by interpolation, and the length distortion factor of each intersection point in the width direction is obtained, and the actual length of the vertical coordinate of each intersection point from the leftmost reference line of the rail profile is calculated.

[0144] Through the entire cutting process, the image size of each pixel on the rail profile image is converted into the actual size, which is based on the size of the lower edge line of the roller and the leftmost reference line of the rail profile, and finally the steel plate profile data based on the actual size is obtained.

[0145] The steel plate profile measurement device and the profile data calculation method based on the line array camera and the laser speed measuring instrument provided by the embodiment of the present application are independently operated as a system, and are used in actual production after field installation and debugging. The beneficial effects brought by the technical scheme are:

[0146] The steel plate profile measurement device and the profile data calculation method based on the line array camera and the laser speed measuring instrument provided by the embodiment of the present application are a kind of thick plate profile measurement method with high measurement precision, strong real-time performance and strong environmental adaptability, which can realize accurate measurement of thick plate profile, and provide actual size data and coordinates relative to the lower edge line of the roller, which can provide accurate input data for optimizing cutting, thereby supporting automatic cutting of cutting head, and has good practical application value. At the same time, the invention can replace manual observation post workers to realize staff reduction and efficiency increase.

[0147] In summary, the steel rail profile measurement method provided by the embodiment of the present application realizes:

[0148] (1) A thick plate profile measurement device (including the installation position relationship of each device) and its measurement control logic composed of 2 line array cameras, a high-brightness linear LED light source, a laser speed measuring instrument, a light curtain, a pulse distributor, 2 sets of logic control units and a set of PLC.

[0149] (2) An actual profile calculation method for converting the profile size of the steel plate from the image size to the actual size by using the cutting auxiliary line method and based on the width size mapping table and the length distortion factor.

[0150] In the embodiment of the present application, a steel plate profile measurement method is also provided, as described in the following embodiment. Since the principle of solving the problem of the method is similar to that of the steel plate profile measurement device, the implementation of the method can be referred to the implementation of the method, and the repeated parts will not be described again.

[0151] Figure 15 The flowchart of the measuring method of the steel plate profile in the embodiment of the present application is shown in FIG. 1, which comprises the following steps: Figure 15

[0152] Step 101: When detecting that the head of the steel plate to be measured runs to the laser speedometer between the first line array camera and the second line array camera, the laser speedometer sends out a first pulse signal and a second pulse signal, and the first level control signal and the second level control signal sent by the PLC controller are both high level signals;

[0153] Step 102: The first AND gate logic control unit sends out a first control signal according to the first pulse signal and the high level signal, and the second AND gate logic control unit sends out a second control signal according to the second pulse signal and the high level signal, so as to control the first line array camera and the second line array camera to start photographing at the same time, and the PLC controller starts real-time displacement integration to obtain the real-time integrated displacement of the steel plate to be measured; wherein the output frequency of the speedometer pulse signal changes with the running speed of the steel plate to be measured, and the speedometer sends out a pulse signal every time the steel plate runs a fixed pixel precision displacement, so that the camera line frequency matches the running speed of the steel plate;

[0154] Step 103: When detecting that the real-time integrated displacement of the steel plate to be measured reaches the distance between the first line array camera and the second line array camera, the PLC controller stops integration, and the second level control signal sent by the PLC controller is a second low level signal;

[0155] Step 104: The second AND gate logic control unit sends out a second control signal according to the second pulse signal and the second low level signal, so as to control the second line array camera to stop photographing, and obtain the head image of the steel plate to be measured;

[0156] Step 105: When detecting the steel plate to be measured in front of the laser speedometer, the first level control signal sent by the PLC controller is a first low level signal;

[0157] Step 106: The first AND gate logic control unit sends out a first control signal according to the first pulse signal and the first low level signal, so as to control the first line array camera to stop photographing, and obtain the middle and tail images of the steel plate to be measured;

[0158] Step 107: The image processing workstation performs splicing and edge detection processing on the head image of the steel plate to be measured and the middle and tail images of the steel plate to be measured, and obtains the profile image of the steel plate to be measured; the profile image of the steel plate to be measured is subjected to pixel coordinate conversion and calculation by using the cutting auxiliary line method, and finally the steel plate profile data based on the actual size is obtained.

[0159] ​In one embodiment, the contour image of the steel plate to be tested is converted and calculated pixel by pixel using the cutting auxiliary line method, and the steel plate contour data based on the actual size is finally obtained, which can include:

[0160] A mapping table of image size and actual size corresponding to the conversion of steel plate width for different steel plate thicknesses, and a distortion factor table for length corresponding to different steel plate thicknesses are constructed;

[0161] According to the mapping table of image size and actual size corresponding to the conversion of steel plate width for different steel plate thicknesses, and the distortion factor table for length corresponding to different steel plate thicknesses, the image size of each point on the contour image of the steel plate to be tested is converted into actual size using the cutting auxiliary line method, and the steel plate contour data based on the actual size is finally obtained.

[0162] In one embodiment, according to the mapping table of image size and actual size corresponding to the conversion of steel plate width for different steel plate thicknesses, and the distortion factor table for length corresponding to different steel plate thicknesses, the image size of each point on the contour image of the steel plate to be tested is converted into actual size using the cutting auxiliary line method, and the steel plate contour data based on the actual size is finally obtained, which can include:

[0163] The contour image of the steel plate is cut pixel by pixel from the leftmost end of the steel plate contour at a pixel length step using the cutting auxiliary line, and all intersection points of the cutting auxiliary line and the steel plate contour and the intersection points with the lower edge line of the roller are calculated until there is no intersection point between the cutting auxiliary line and the steel plate contour.

[0164] For each cutting, the distance of each intersection point from the lower edge line of the roller in the width direction is calculated, and the pixel number of each intersection point from the leftmost reference line of the rail contour is calculated.

[0165] Based on the mapping data in the mapping table of image size and actual size corresponding to the conversion of steel plate width for different steel plate thicknesses, the distance of each intersection point from the lower edge line of the roller in the width direction is calculated by interpolation, and the actual length of each intersection point from the lower edge of the roller is obtained.

[0166] Based on the distortion factor data in the distortion factor table for length corresponding to different steel plate thicknesses, the horizontal coordinates of each intersection point are calculated by interpolation, and the length distortion factor of each intersection point in the width direction is obtained, and the actual length of the vertical coordinate of each intersection point from the leftmost reference line of the rail contour is calculated.

[0167] Through the entire cutting process, the image size of each pixel on the rail contour image is converted into actual size based on the size of the lower edge line of the roller and the leftmost reference line of the rail contour, and the steel plate contour data based on the actual size is finally obtained.

[0168] In one embodiment, the measuring device of the steel plate profile can also calculate the camera line frequency according to the following formula:

[0169] LFi=Vi / PixL;

[0170] wherein, PixL=RTW / LCR; LFi is the camera line frequency, Vi is the real-time speed of the steel plate, PixL is the pixel accuracy, RTW is the roller width, and LCR is the resolution of the camera.

[0171] The embodiment of the present application also provides a computer device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the above-mentioned steel plate profile measurement method when executing the computer program.

[0172] The embodiment of the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executable on a processor to implement the above-mentioned steel plate profile measurement method.

[0173] The embodiment of the present application also provides a computer program product, which comprises a computer program, and the computer program is executable on a processor to implement the above-mentioned steel plate profile measurement method.

[0174] The beneficial technical effects of the steel plate profile measurement scheme provided by the embodiment of the present application are as follows: first, the laser speed measuring instrument is used to measure the real-time speed of the steel plate or the real-time pulse signal corresponding to the speed of the steel plate in the whole process of measuring the profile of the steel plate, rather than the speed of the roller or the pulse signal of the roller encoder, so that the line frequency of the line array camera can be matched with the actual speed of the steel plate, and the accurate acquisition of the image frame of the steel plate can be realized; second, the embodiment of the present application adopts the structure of two rows of line array cameras (the first line array camera and the second line array camera) + the laser speed measuring instrument, and the laser speed measuring instrument is arranged between the two rows of cameras, so that the cameras can always work under the control of the laser speed measuring instrument, and the influence of the "speed measurement blind area" on the profile measurement accuracy can be avoided; third, the embodiment of the present application is provided with an AND gate logic control unit (the first AND gate logic control unit and the second AND gate logic control unit), the start and stop of the line array camera can be flexibly controlled online, the working window of the two rows of cameras can be accurately controlled in cooperation with the real-time displacement integration of the PLC, and the independent measurement of the "head" profile and the "middle + tail" profile of the steel plate can be realized; fourth, the actual size coordinates of each pixel point on the profile of the steel plate are quickly calculated through the pixel coordinate conversion and calculation by the cutting auxiliary line method, and the profile data of the steel plate based on the actual size is finally obtained, and the calculation response of the method is fast and the calculation accuracy meets the process and production requirements. In summary, the present application can improve the measurement accuracy of the profile of the steel plate.

[0175] Those skilled in the art will appreciate that embodiments of the application can be devised for a method, a system, or a computer program product. Accordingly, the present application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0176] The present application is described in reference to the flowchart and / or block diagrams of the method, apparatus (system) and computer program product according to embodiments of the application. It will be understood that each block of the flowchart and / or block diagrams, and combinations of blocks in the flowchart and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processing device or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks.

[0177] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks.

[0178] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks.

[0179] The specific embodiments described above are illustrative of specific embodiments of the present application. However, any modification and alteration of the above described embodiments should be easily apparent to those skilled in the art from this disclosure without departing from the spirit and scope of the present application. Accordingly, the scope of the present application should be determined by the appended claims and their legal equivalents rather than by the described embodiments.

Claims

1. A measuring device for the profile of a steel plate, characterized in that, include: The system includes a light curtain, a first line-scan camera, a second line-scan camera, a laser velocimeter, a first AND gate logic control unit, a second AND gate logic control unit, a PLC controller, and an image processing workstation, among which: A laser velocimeter, located between the first and second linear array cameras, is used to measure the real-time speed of the steel plate under test and provide the real-time speed to the PLC controller; it provides a first pulse signal to drive the first linear array camera to take a picture and a second pulse signal to drive the second linear array camera to take a picture; wherein, the output frequency of the velocimeter's pulse signal changes with the running speed of the steel plate under test, and the velocimeter emits a pulse signal for every fixed pixel precision displacement of the steel plate, so that the camera's line frequency matches the running speed of the steel plate; The PLC controller is used to obtain the real-time integral displacement of the steel plate under test based on the real-time speed, and to issue a second-level control signal based on the real-time integral displacement of the steel plate under test; and to issue a first-level control signal based on the light curtain detection status. The first AND gate logic control unit is used to obtain a first control signal by ANDing the first pulse signal and the first level control signal of the PLC, so as to control the first line scan camera to take pictures. The second AND gate logic control unit is used to obtain a second control signal by ANDing the second pulse signal and the second level control signal of the PLC, so as to control the second linear scan camera to take pictures; The second linear array camera is used to take pictures of the head of the steel plate to be tested according to the second control signal. The first linear array camera is used to take pictures of the middle and tail of the steel plate under test according to the first control signal; The image processing workstation is used to stitch together and perform edge detection processing on the head image of the steel plate under test, as well as the middle and tail images of the steel plate under test, to obtain the outline image of the steel plate under test. The method of cutting auxiliary lines is used to perform pixel-by-pixel coordinate transformation and calculation on the contour image of the steel plate to be tested, and finally obtain the steel plate contour data based on the actual size. This includes: constructing a mapping table between the image size converted to the actual size for different steel plate thicknesses and the image size converted to the actual size for different steel plate thicknesses, and a distortion factor table for different lengths for different steel plate thicknesses; according to the mapping table between the image size converted to the actual size for different steel plate thicknesses and the distortion factor table for different lengths for different steel plate thicknesses, the method of cutting auxiliary lines is used to convert the image size of each point on the contour image of the steel plate to be tested into the actual size, and finally obtain the steel plate contour data based on the actual size.

2. The apparatus as claimed in claim 1, characterized in that, Also includes: A pulse distributor is used to expand the pulse signal of the laser velocimeter, converting it from one pulse signal into the first pulse signal and the second pulse signal for output. Linear LED light source, used to provide the light source required for steel plate profile measurement.

3. The apparatus as described in claim 1, characterized in that, The first line array camera, the second line array camera, the laser velocimeter, and the light curtain are installed on the gantry frame in front of the head cutter, while the first AND gate logic control unit, the second AND gate logic control unit, and the PLC controller are placed in the electrical cabinet.

4. A method for measuring the profile of a steel plate, characterized in that, include: When the laser velocimeter detects that the head of the steel plate to be tested has moved to the laser velocimeter between the first line array camera and the second line array camera, the laser velocimeter sends out the first pulse signal and the second pulse signal, and the first level control signal and the second level control signal sent by the PLC controller are both high level signals. The first AND gate logic control unit generates a first control signal based on the AND operation of the first pulse signal and a high-level signal, and the second AND gate logic control unit generates a second control signal based on the AND operation of the second pulse signal and a high-level signal, so as to control the first and second line-scan cameras to start taking pictures simultaneously. The PLC controller starts real-time displacement integration to obtain the real-time integrated displacement of the steel plate under test. Among them, the output frequency of the pulse signal of the tachometer changes with the running speed of the steel plate under test. For every fixed pixel precision displacement of the steel plate, the tachometer generates a pulse signal, so that the camera's line frequency matches the running speed of the steel plate. When the real-time integrated displacement of the steel plate under test reaches the distance between the first line array camera and the second line array camera, the PLC controller stops integrating and the second level control signal issued by the PLC controller is the second low level signal. The second AND gate logic control unit generates a second control signal based on the AND of the second pulse signal and the second low-level signal, so as to control the second linear array camera to stop taking pictures and obtain the head image of the steel plate to be tested. When the light curtain in front of the laser velocimeter detects the steel plate to be tested, the first level control signal sent by the PLC controller is the first low level signal. The first AND gate logic control unit generates a first control signal based on the AND of the first pulse signal and the first low-level signal, so as to control the first linear array camera to stop taking pictures and obtain images of the middle and tail of the steel plate under test. The image processing workstation stitches together the head image of the steel plate under test, as well as the middle and tail images of the steel plate under test, and performs edge detection processing to obtain the outline image of the steel plate under test. The method of cutting auxiliary lines is used to perform pixel-by-pixel coordinate transformation and calculation on the contour image of the steel plate to be tested, and finally obtain the steel plate contour data based on the actual size. This includes: constructing a mapping table between the image size converted to the actual size for different steel plate thicknesses and the image size converted to the actual size for different steel plate thicknesses, and a distortion factor table for different lengths for different steel plate thicknesses; according to the mapping table between the image size converted to the actual size for different steel plate thicknesses and the distortion factor table for different lengths for different steel plate thicknesses, the method of cutting auxiliary lines is used to convert the image size of each point on the contour image of the steel plate to be tested into the actual size, and finally obtain the steel plate contour data based on the actual size.

5. The method as described in claim 4, characterized in that, Based on the mapping table between image dimensions and actual dimensions corresponding to different steel plate thicknesses and the distortion factor table for different steel plate thicknesses, the image dimensions of each point on the contour image of the steel plate to be measured are converted into actual dimensions using the cutting auxiliary line method. Finally, steel plate contour data based on actual dimensions is obtained, including: The cutting auxiliary line is used to cut the outline image of the steel plate to be tested pixel by pixel from the leftmost end of the steel plate outline in a step of one pixel length. All intersections between the cutting auxiliary line and the steel plate outline, as well as the intersections with the lower edge line of the roller conveyor, are calculated until there are no more intersections between the cutting auxiliary line and the steel plate outline. For each cut, calculate the distance in the width direction between each intersection point and the lower edge line of the roller conveyor, and calculate the number of pixels between each intersection point and the leftmost reference line of the rail profile. Based on the mapping data in the mapping table of image size and actual size corresponding to different steel plate thicknesses for steel plate width conversion, the distance between each intersection point and the lower edge line of the roller conveyor in the width direction is interpolated to obtain the actual length of each intersection point from the lower edge of the roller conveyor. Based on the distortion factor data in the distortion factor table for different steel plate thicknesses, the x-coordinate of each intersection point is interpolated to obtain the length distortion factor of each intersection point in the width direction, and the actual length of the y-coordinate of each intersection point from the leftmost reference line of the rail profile is calculated. Through the entire cutting process, the image size of each pixel on the rail profile image is converted into the actual size. The actual size is based on the size of the lower edge line of the roller conveyor and the leftmost reference line of the rail profile, and finally the steel plate profile data based on the actual size is obtained.

6. The method as described in claim 4, characterized in that, This also includes calculating the camera line frequency using the following formula: in, For camera line frequency, For the real-time speed of the steel plate, RTW is the pixel precision, RTW is the roller width, and LCR is the camera resolution.

7. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 4 to 6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 4 to 6.

9. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 4 to 6.

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