Steel plate contour dimension measurement method based on surface detection platform

Abstract

The invention discloses a steel plate contour dimension measurement method based on a surface detection platform, and belongs to the technical field of machine vision detection, and the method comprises the steps: transforming the surface detection platform, installing a laser transmitter between every two adjacent cameras in the same group of cameras in the surface detection platform, a modified surface detection platform is obtained; wherein light spots projected to the measured steel plate by each laser generator can be simultaneously collected by the cameras on the two sides of the laser generator; a preset calibration plate is adopted to calibrate each camera in the modified surface detection platform; acquiring a surface image of the detected steel plate by using the calibrated group of cameras; and calculating the overall dimension of the measured steel plate based on the surface image of the measured steel plate. According to the invention, the overall dimension of the steel plate is measured, the cost can be effectively reduced, and higher measurement precision can be obtained by using the high-resolution image of the surface detection platform.

Description

Technical Field

[0001] The invention relates to the technical field of machine vision detection, and in particular to a steel plate contour dimension measurement method based on a surface detection platform. Background Art

[0002] In the precision machining and quality control system of modern manufacturing, it is very important to accurately and efficiently measure the contour dimensions of steel plates. This link is not only a key step to ensure that product quality meets strict standards, but also a key factor in significantly improving production efficiency. Accurate measurement of the contour dimensions of steel plates can not only instantly verify whether the production process meets the established standards and effectively judge the quality level of the finished steel plates, but also provide crucial data support for subsequent precise shearing, assembly and other process flows, thereby optimizing the production process and reducing material waste.

[0003] For the measurement of steel plate contour dimensions, the traditional measurement method that relies on manual operation (using tools such as rulers and calipers) has problems such as low efficiency and accuracy greatly affected by human factors. At present, the steel plate contour measurement method based on machine vision technology has become a mainstream trend. Among them, linear array cameras are favored due to their high scanning speed and precise capture capabilities. However, although linear array camera technology has shown great potential in steel plate contour measurement, it still faces some challenges in practical applications. High hardware cost is one of the primary problems, which leads to some companies being limited in the number and resolution of cameras configured, which in turn affects the accuracy and comprehensiveness of the measurement. Summary of the invention

[0004] The present invention provides a steel plate contour dimension measurement method based on a surface detection platform to solve the technical problem that the solution of using linear array camera technology to measure the steel plate contour dimension is high in hardware cost, which leads to some companies being restricted in configuring the number and resolution of cameras, thus affecting the measurement accuracy and comprehensiveness.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] On the one hand, the present invention provides a method for measuring the contour size of a steel plate based on a surface detection platform, wherein the surface detection platform includes two groups of cameras, one group of cameras is located above the steel plate to be measured, and the other group of cameras is located below the steel plate to be measured, and the cameras in the same group are evenly distributed laterally along the steel plate to be measured; the method includes:

[0007] The surface detection platform is modified, and a laser emitter is respectively installed between every two adjacent cameras in the same group of cameras in the surface detection platform, so as to obtain a modified surface detection platform; wherein the light spot projected by each laser generator onto the steel plate to be tested can be simultaneously collected by the cameras on both sides thereof;

[0008] Each camera in the modified surface inspection platform is calibrated using a preset calibration plate;

[0009] A set of calibrated cameras is used as an acquisition platform to acquire the surface image of the steel plate under test;

[0010] Based on the collected surface image of the steel plate being tested, the outline size of the steel plate being tested is calculated.

[0011] Further, the preset calibration plate includes a first calibration block and a second calibration block;

[0012] The first calibration block and the second calibration block are respectively slidably installed on the slide rail and can move along the slide rail respectively. When calibrating the camera, the first calibration block and the second calibration block are respectively moved along the slide rail to the front of the camera to be calibrated, so as to calibrate the camera using the first calibration block and the second calibration block; wherein, the first calibration block is used to calibrate the resolution of the camera to construct a resolution matrix of a vector form structure corresponding to the camera, and the second calibration block is used to calibrate the deviation angle of the camera.

[0013] Furthermore, the first calibration block is a layout of light bands with equal spacing and width; when calibrating the camera, the camera acquires an image of the first calibration block, determines the camera resolution at the coordinates of the pixel positions of different light bands by the pixel width of the light bands in the image and the actual light band width, and then obtains the resolution of each horizontal pixel position on the image by quadratic curve fitting, so as to construct a resolution matrix corresponding to the camera;

[0014] The second calibration block is composed of two symmetrical 45° inclined parallelogram light strips, which are used to calibrate the camera's deflection angle θ, that is, the degree of inclination between the camera target surface straight line and the measured target position, to ensure that the measured target in the multi-camera system can be accurately projected to a unified reference line; wherein, the expression of the camera's deflection angle θ is as follows:

[0015]

[0016] In the formula, x 1 Indicates the pixel width of the left light band of the second calibration block in the image captured by the camera during calibration; x 2 Indicates the pixel width of the right light band of the second calibration block in the image captured by the camera during calibration.

[0017] Furthermore, after obtaining the resolution matrix corresponding to the camera, the method further includes:

[0018] Every two adjacent cameras of the acquisition platform form a binocular stereo vision system, and multiple binocular stereo vision systems are obtained, from which two binocular stereo vision systems that are farthest apart and can capture the steel plate to be tested are selected, and are respectively recorded as the first binocular stereo vision system and the second binocular stereo vision system;

[0019] Calculate the distance between the surface of the steel plate and the reference plane at a certain coordinate position under the first binocular stereo vision system and the distance between the surface of the steel plate and the reference plane at a certain coordinate position under the second binocular stereo vision system;

[0020] The value of the distance between the surface of the steel plate and the reference plane at a certain coordinate position calculated by the first binocular stereo vision system and the value of the distance between the surface of the steel plate and the reference plane at a certain coordinate position calculated by the second binocular stereo vision system are combined to draw a straight line in the pixel coordinates of the two values ​​in the width direction of the measured steel plate, and the value of the distance between the surface of the steel plate and the reference plane corresponding to each pixel position of each camera along the width direction of the measured steel plate is obtained by the straight line equation and the pixel position along the width direction of the measured steel plate, and the value is used as an element to construct a matrix C;

[0021] The resolution matrix corresponding to the camera is corrected using matrix C, and the corrected resolution matrix is ​​used as the final calibration result of the corresponding camera; wherein, the formula for correcting the resolution matrix corresponding to the camera is:

[0022]

[0023] Where E′ represents the corrected resolution matrix; E represents the original resolution matrix; n represents the number of camera pixels; f represents the focal length of the lens; and u represents the target size of the camera.

[0024] Furthermore, the calculation formula of the value of the steel plate surface distance from the reference plane corresponding to the binocular stereo vision system is:

[0025]

[0026] Where c represents the distance between the steel plate surface and the reference plane; B represents the baseline distance between the left and right cameras in the binocular stereo vision system for which the c value is to be calculated; f represents the focal length of the camera lens in the binocular stereo vision system for which the c value is to be calculated; D represents the parallax formed by the same viewpoint captured by the left and right cameras in the binocular stereo vision system for which the c value is to be calculated; H 0 Indicates the distance from the calibration plane corresponding to the binocular stereo vision system for which the c value is to be calculated to the camera.

[0027] Furthermore, based on the collected surface image of the steel plate under test, the outline size of the steel plate under test is calculated, including:

[0028] The light spot position in the surface image of the steel plate under test is extracted to determine the boundary pixels where the fields of view of adjacent cameras overlap, so as to determine the starting pixel and ending pixel of the steel plate area in the image captured by each camera; wherein, for the camera located at the edge of the operating side, the starting pixel of the steel plate area in the image captured by it is the pixel where the light spot position in the image is located, and the ending pixel of the steel plate area is the pixel at the edge of the operating side; for the camera located at the edge of the transmission side, the starting pixel of the steel plate area in the image captured by it is the pixel at the edge of the transmission side, and the ending pixel of the steel plate area is the pixel where the light spot position in the image is located; the starting pixel and ending pixel of the steel plate area in the images captured by the remaining cameras are the pixels where the light spot positions on both sides of the image are located respectively;

[0029] Based on the calibration results of each camera and the starting and ending pixels of the steel plate area in the image captured by each camera, the length, width and coordinates of the edges of the steel plate are calculated.

[0030] Furthermore, the surface detection platform also includes a laser velocimeter; at the lateral position of the steel plate where the laser velocimeter is located, the length of the steel plate is directly output by the laser velocimeter; the length of the steel plate at other positions is calculated as follows:

[0031] Count the number of all pixels along the length direction of the steel plate at the transverse position of the steel plate where the laser velocimeter is located, and divide the length of the steel plate at the transverse position of the steel plate where the laser velocimeter is located by the number of all pixels along the length direction of the steel plate at the transverse position of the steel plate where the laser velocimeter is located to obtain the longitudinal resolution;

[0032] At other transverse positions of the steel plate other than the transverse position of the steel plate where the laser velocimeter is located, the length of the steel plate at the corresponding position is obtained by multiplying the number of all pixels along the length direction of the steel plate at this position by the longitudinal resolution.

[0033] Furthermore, the width W of the steel plate at the length position l is l for:

[0034]

[0035] In the formula, sum() represents vector summation; Indicates the pixel position p corresponding to the i-th camera is ~p it The resolution matrix of the range; p is and p it Respectively represent the position coordinates of the starting pixel and the ending pixel of the steel plate area after the i-th camera removes the overlapping pixels; θ i represents the deflection angle of the i-th camera; N represents the number of cameras on the acquisition platform.

[0036] Furthermore, the operating side edge position coordinate P at the length position l of the steel plate lo for:

[0037]

[0038] In the formula, sum() represents vector summation; Indicates the pixel position p corresponding to camera k located at the edge of the operating side kt ~p kw The resolution matrix of the range; p kt represents the ending pixel position coordinates of the steel plate area after camera k removes the overlapping pixels; p kw represents the maximum pixel position of camera k, θ k represents the deflection angle of camera k.

[0039] Furthermore, the transmission side edge position coordinate P at the length position l of the steel plate is l d for:

[0040] P l d =P l o +W l

[0041] Where P l o W is the position coordinate of the edge of the operating side at the length position l of the steel plate; l is the width of the steel plate at length position l.

[0042] On the other hand, the present invention further provides an electronic device, comprising a processor and a memory; wherein the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the above method.

[0043] In yet another aspect, the present invention further provides a computer-readable storage medium, wherein at least one instruction is stored in the storage medium, and the instruction is loaded and executed by a processor to implement the above method.

[0044] The beneficial effects brought about by the technical solution provided by the present invention include at least:

[0045] The present invention makes a minor modification to the traditional surface quality inspection platform, and with the help of the high-resolution image data output by the platform, after integration and calibration, significantly reduces the measurement error, realizes high-precision contour dimension measurement, and eliminates the interference caused by the running jitter and thickness change of the steel plate by building a binocular stereo vision system. The present invention can enrich the functions of the surface inspection platform, while reducing the cost loss caused by adding the contour detection function alone, which not only effectively reduces the measurement cost, but also ensures higher measurement accuracy and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1 It is a schematic diagram of the execution flow of the steel plate contour dimension measurement method based on the surface detection platform provided in an embodiment of the present invention;

[0048] Figure 2 It is a schematic diagram of hardware transformation of a surface quality detection system provided by an embodiment of the present invention;

[0049] Figure 3 is a structural diagram of a calibration plate provided in an embodiment of the present invention;

[0050] Figure 4 is a schematic diagram of camera deflection angle calculation provided by an embodiment of the present invention;

[0051] Figure 5 It is a schematic diagram of calculating the outline size of a steel plate provided in an embodiment of the present invention;

[0052] Figure 6 Schematic diagram of distance calculation of binocular stereo vision system provided by an embodiment of the present invention;

[0053] Figure 7 is a schematic diagram of a process of constructing a distance matrix C provided by an embodiment of the present invention;

[0054] Figure 8 It is a system block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] First of all, it should be noted that in the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplarily" is intended to present the concept in a concrete way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0057] First embodiment

[0058] This embodiment provides a steel plate contour size measurement method based on a surface detection platform. The steel plate contour size measurement is achieved by slightly modifying the steel plate surface quality detection system. The method can be implemented by an electronic device. The execution process of the method is as follows: Figure 1 As shown, the following steps are included:

[0059] S1, modifying the surface detection platform, installing a laser transmitter between every two adjacent cameras in the same group of cameras in the surface detection platform, to obtain a modified surface detection platform;

[0060] It should be noted that, Figure 2 As shown, the traditional surface inspection system includes two groups of cameras, one group of cameras is located above the steel plate to be tested, for photographing the upper surface of the steel plate, and the other group of cameras is located below the steel plate to be tested, for photographing the lower surface of the steel plate, and the cameras in the same group are in a straight line and evenly distributed laterally along the steel plate to be tested; specifically, the upper and lower surfaces of the surface quality inspection system in this embodiment are each composed of 4 cameras, the cameras are evenly distributed along the width direction of the roller, and the laser generator is installed in the middle position of adjacent cameras; when measuring the actual contour size, the camera on the upper surface can be used to preliminarily measure the contour, and the contour measured by the camera on the lower surface can be used for correction (the correction method includes but is not limited to averaging the results obtained on the upper and lower surfaces).

[0061] The laser generator is triggered in a stroboscopic manner, and the laser it emits is projected onto the steel plate under test. For each laser generator, the light it emits can be clearly captured in the images collected by all cameras. By extracting the position of the light spot in the image, the boundary pixels where the fields of view of adjacent cameras overlap can be determined.

[0062] S2, calibrating each camera in the modified surface inspection platform using a preset calibration plate;

[0063] It should be noted that, in this embodiment, the designed calibration plate is used to complete the calibration of the camera to construct a resolution matrix with a vector structure, which is used to eliminate the influence of lens distortion and camera attitude angle, and at the same time calibrate the camera deviation angle, so that when performing subsequent dimensional measurement, the tangential angle between multiple cameras is taken into account to complete the dimensional measurement, and the contour and dimensional data of the steel plate are calculated.

[0064] Specifically, the calibration plate designed in this embodiment is as follows: Figure 3As shown, it consists of a first calibration block and a second calibration block, in which the white part is the light band, and the black part represents the stable base of the body. The two calibration blocks are flexibly installed on the slide rail, and through the precise movement of the slide rail, they can be calibrated one by one for different camera positions. Among them, the first calibration block is a light band layout with equal spacing and width. The camera acquires the image of the first calibration block, and the camera resolution at the coordinates of the pixel position of different light bands is determined by the pixel width of the light band in the image and the actual light band width. Then, the resolution of each horizontal pixel position on the image is obtained by quadratic curve fitting, and the resolution matrix is ​​constructed. The second calibration block is composed of two symmetrical 45° inclined parallelogram light bands, which are used to calibrate the camera's deflection angle θ, that is, the degree of inclination between the camera target surface straight line and the target position to be measured, to ensure that the measured target in the multi-camera system can be accurately projected to a unified reference line, such as Figure 4 As shown, the deflection angle θ is expressed as:

[0065]

[0066] In the formula, x 1 Indicates the pixel width of the light band on the left side of the second calibration block in the acquired image; x 2 Indicates the pixel width of the light band on the right side of the second calibration block in the acquired image.

[0067] S3, using a set of calibrated cameras as an acquisition platform to acquire the surface image of the steel plate under test;

[0068] Among them, it should be noted that a group of cameras on the upper surface can be used as an acquisition platform to acquire the surface image of the steel plate to be measured, and then the subsequent steel plate size calculation can be performed; a group of cameras on the lower surface can be used as an acquisition platform to acquire the surface image of the steel plate to be measured, and then the subsequent steel plate size calculation can be performed; a group of cameras on the upper and lower surfaces can be used as acquisition platforms respectively, and the surface images of the steel plate to be measured can be acquired respectively, and then the subsequent steel plate size calculation can be performed respectively, and then the upper surface camera can be used to preliminarily measure the contour, and the contour measured by the lower surface camera can be used to correct the preliminary measurement result.

[0069] S4, calculating the outline size of the steel plate under test based on the collected surface image of the steel plate under test;

[0070] Specifically, in this embodiment, the implementation process of the above S4 is as follows:

[0071] S41, extract the position of the light spot in the surface image of the steel plate under test, so as to determine the boundary pixels where the fields of view of adjacent cameras overlap, so as to determine the starting pixel and the ending pixel of the steel plate area in the image captured by each camera; wherein, for the camera located at the edge of the operating side, the starting pixel of the steel plate area in the image captured by it is the pixel where the light spot position in the image is located, and the ending pixel of the steel plate area is the operating side edge pixel; for the camera located at the edge of the transmission side, the starting pixel of the steel plate area in the image captured by it is the transmission side edge pixel, and the ending pixel of the steel plate area is the pixel where the light spot position in the image is located; the starting pixel and the ending pixel of the steel plate area in the image captured by the remaining cameras are the pixels where the light spot positions on both sides of the image are located, respectively;

[0072] S42, based on the calibration results of each camera and the starting pixel and ending pixel of the steel plate area in the image captured by each camera, the length, width and coordinates of the edges of the steel plate on both sides are calculated, such as Figure 5 As shown;

[0073] Furthermore, the surface detection platform also includes a laser velocimeter; at the lateral position of the steel plate where the laser velocimeter is located, the length of the steel plate is directly output by the laser velocimeter; the length of the steel plate at other positions is calculated as follows:

[0074] Count the number of all pixels along the length direction of the steel plate at the transverse position of the steel plate where the laser velocimeter is located, and divide the length of the steel plate at the transverse position of the steel plate where the laser velocimeter is located by the number of all pixels along the length direction of the steel plate at the transverse position of the steel plate where the laser velocimeter is located to obtain the longitudinal resolution;

[0075] At other transverse positions of the steel plate other than the transverse position of the steel plate where the laser velocimeter is located, the length of the steel plate at the corresponding position is obtained by multiplying the number of all pixels along the length direction of the steel plate at this position by the longitudinal resolution.

[0076] Furthermore, the width W of the steel plate at the length position l is l for:

[0077]

[0078] In the formula, sum() represents vector summation; Indicates the pixel position p corresponding to the i-th camera is ~p it The resolution matrix of the range; p is and p it Respectively represent the position coordinates of the starting pixel and the ending pixel of the steel plate area after the i-th camera removes the overlapping pixels; θ i represents the deflection angle of the i-th camera; N represents the number of cameras on a single surface, and specifically, in this embodiment, its value is 4.

[0079] Furthermore, the operating side edge position coordinate P at the length position l of the steel plate l o for:

[0080]

[0081] In the formula, is the pixel position p corresponding to camera k kt ~p kw The resolution matrix of the range; p kt p is the ending pixel position coordinate of the steel plate area after camera k removes the overlapping pixels; kw is the maximum pixel position of camera k, θ k is the deflection angle of camera k; camera k is located at the edge of the operating side; the coordinate origin O is defined as p kw Location.

[0082] Furthermore, the transmission side edge position coordinate P at the length position l of the steel plate is l d for:

[0083] P l d =P l o +W l

[0084] Where P l o W is the position coordinate of the edge of the operating side at the length position l of the steel plate; l is the width of the steel plate at length position l.

[0085] Furthermore, after obtaining the resolution matrix corresponding to the camera, the method further includes: constructing a binocular stereo system based on the laser point features captured in the overlapping area shot by adjacent cameras, and using the binocular stereo vision system constructed by multiple groups of adjacent cameras to compensate the resolution matrix again to eliminate the interference of steel plate thickness and operation jitter, such as Figure 6 As shown, the specific implementation process is as follows:

[0086] The number of cameras arranged on the surface, N, can form N-1 binocular stereo vision systems. Specifically, in this example, a single surface can form three binocular stereo vision systems. The two binocular stereo vision systems with the farthest distance from each other that can capture the steel plate are selected, and the value c of the distance between the surface of a steel plate and the reference plane is calculated by the following formula: m1 and c m2 :

[0087]

[0088] Where B represents the baseline distance between the left and right cameras in the binocular stereo vision system; f represents the focal length of the lens; D represents the parallax formed by the same viewpoint captured by the left and right cameras in the binocular stereo vision system; H 0 Indicates the distance from the calibration plane to the camera.

[0089] like Figure 7 As shown in the figure, the maximum position of the camera on the operating side of the reference plane is taken as the origin, the x-axis is defined along the width direction of the steel plate, and the y-axis is the vertical direction of the reference plane, which represents the distance from the measuring point to the reference plane. According to the arrangement position of each camera, the horizontal pixel position of the camera image is mapped to the x-axis of the above coordinate system, and the measured c m1 and c m2 The x coordinate corresponding to the value in this coordinate system is x m1 and x m2 , with point (x m1 , c m1 ) and point (x m2 , c m2 ) In this coordinate system, the equation of the straight line passing through the two points is calculated; the coordinate value of each pixel position in the x-axis direction is substituted into the straight line equation to obtain the distance c corresponding to the pixel position from the reference plane. i , these pairs of values ​​are mapped back to the image coordinate system of each camera, and the value c of each pixel position under each camera i Combine into a matrix C = [c 1 ,c 2 ...c n ]; It should be noted that the purpose of calculating the matrix C in this embodiment is to calculate the distance from the steel plate surface photographed at each pixel point of the camera to the reference plane. Since only the area covered by the binocular can accurately measure the distance from the steel plate to the reference plane, other positions can only be measured by c m1 、c m2 It is calculated by the straight line determined by the two points. C is for each camera. You can see that there are n numbers in C, which is exactly the number of pixels. i Refers to the distance value from the steel plate surface to the reference plane at each pixel position.

[0090] The resolution change caused by the distance matrix C is compensated to the resolution matrix to obtain the resolution matrix E′ after eliminating the influence of the difference in steel plate thickness and the jitter during operation:

[0091]

[0092] Where E represents the original resolution vector; n represents the number of camera pixels; f represents the focal length of the lens; and u represents the target size of the camera.

[0093] In summary, this embodiment provides a steel plate contour dimension measurement method based on a surface detection platform. By making minor modifications to the traditional surface quality detection system, the high-resolution image data output by the system is integrated and calibrated to significantly reduce the measurement error, achieve high-precision contour dimension measurement, and eliminate the interference caused by the jitter and thickness change of the steel plate by building a binocular stereo vision system. The adoption of this solution can enrich the functions of the surface inspection system and reduce the cost loss caused by adding a contour detection function alone. It not only effectively reduces the measurement cost, but also ensures higher measurement accuracy and stability.

[0094] Second embodiment

[0095] This embodiment provides an electronic device, such as Figure 8 As shown, the electronic device includes: a processor and a memory; wherein the processor and the memory can be connected via a communication bus; the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the method of the first embodiment. In addition, the electronic device may also include a transceiver, the processor and the transceiver can be connected via a communication bus, and the transceiver is used to communicate with other devices.

[0096] Next, combine Figure 8 The following is a detailed introduction to the various components of the electronic device:

[0097] Among them, the processor is the control center of the electronic device, and the electronic device may include multiple processors, each of which may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor here may be a processor or a general term for multiple processing elements. For example, the processor is one or more central processing units (CPUs), or other general-purpose processors, application specific integrated circuits (ASICs), or one or more integrated circuits configured to implement an embodiment of the present invention, such as one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (field programmable gate arrays, FPGAs), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor may execute various functions of the electronic device by running or executing software programs stored in the memory and calling data stored in the memory.

[0098] In a specific implementation, as an embodiment, the processor may include one or more CPUs, such as Figure 8 The CPU0 and CPU1 shown in the figure are, of course, only exemplary.

[0099] The memory is used to store the software program for executing the solution of the present invention, and the execution is controlled by the processor. The specific implementation method can refer to the above method embodiment and will not be repeated here.

[0100] Optionally, the memory may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may be integrated with the processor or exist independently and accessed through the interface circuit ( Figure 8 (not shown) is coupled to the processor, which is not specifically limited in this embodiment of the present invention.

[0101] The transceiver may include a receiver and a transmitter ( Figure 8 The receiver is used to implement the receiving function, and the transmitter is used to implement the sending function. The transceiver can be integrated with the processor or exist independently and communicate with the electronic device through the interface circuit ( Figure 8 (not shown) is coupled to the processor, which is not specifically limited in this embodiment of the present invention.

[0102] In addition, it should be noted that Figure 8 The structure of the electronic device shown in the figure does not constitute a limitation on the device, and the actual device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. In addition, the technical effects achieved by the electronic device when executing the method of the first embodiment above can refer to the technical effects described in the first embodiment above, so they are not repeated here.

[0103] Third embodiment

[0104] This embodiment provides a computer-readable storage medium, which stores at least one instruction, and the instruction is loaded and executed by a processor to implement the method of the first embodiment. The computer-readable storage medium may be a ROM, a random access memory, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc. The instructions stored therein may be loaded by a processor in a terminal to execute the method.

[0105] In addition, it should be noted that the present invention can be provided as a method, an apparatus or a computer program product. Therefore, the embodiment of the present invention can be in the form of a full or partial hardware embodiment, a full or partial software embodiment or an embodiment combining software and hardware. Moreover, when implemented using software, the embodiment of the present invention can be in the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program codes. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center containing one or more available media sets. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium. The semiconductor medium may be a solid state hard disk.

[0106] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0107] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable terminal device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0108] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements. In addition, the term "and / or" is only an association relationship describing the associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone, wherein A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding. "At least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can be represented by: a, b, c, ab, ac, bc or abc, where a, b, c can be single or plural.

[0109] In addition, it can be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0110] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0111] In several embodiments provided by the present invention, it should be understood that the disclosed equipment, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of functional modules / units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0112] If the method is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0113] Finally, it should be noted that the above is only a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for ordinary technicians in this technical field, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A method for measuring the contour size of a steel plate based on a surface detection platform, wherein the surface detection platform comprises two groups of cameras, one group of which is located above the steel plate to be measured, and the other group of which is located below the steel plate to be measured, and the cameras in the same group are uniformly distributed laterally along the steel plate to be measured, characterized in that: The method comprises: The surface detection platform is modified, and a laser emitter is respectively installed between every two adjacent cameras in the same group of cameras in the surface detection platform, so as to obtain a modified surface detection platform; wherein the light spot projected by each laser generator onto the steel plate to be tested can be simultaneously collected by the cameras on both sides thereof; Each camera in the modified surface inspection platform is calibrated using a preset calibration plate; A set of calibrated cameras is used as an acquisition platform to acquire the surface image of the steel plate under test; Based on the collected surface image of the steel plate being tested, the outline size of the steel plate being tested is calculated.

2. The steel plate contour dimension measurement method based on the surface detection platform according to claim 1, characterized in that: The preset calibration plate includes a first calibration block and a second calibration block; The first calibration block and the second calibration block are respectively slidably installed on the slide rail and can move along the slide rail respectively. When calibrating the camera, the first calibration block and the second calibration block are respectively moved along the slide rail to the front of the camera to be calibrated, so as to calibrate the camera using the first calibration block and the second calibration block; wherein, the first calibration block is used to calibrate the resolution of the camera to construct a resolution matrix of a vector form structure corresponding to the camera, and the second calibration block is used to calibrate the deviation angle of the camera.

3. The steel plate contour dimension measurement method based on the surface detection platform according to claim 2, characterized in that: The first calibration block is a layout of light bands with equal spacing and width. When calibrating the camera, the camera acquires an image of the first calibration block, determines the camera resolution at the coordinates of the pixel positions of different light bands by the pixel width of the light bands in the image and the actual light band width, and then obtains the resolution of each horizontal pixel position on the image by quadratic curve fitting, so as to construct a resolution matrix corresponding to the camera. The second calibration block is composed of two symmetrical 45° inclined parallelogram light strips, which are used to calibrate the camera's deflection angle θ, that is, the degree of inclination between the camera target surface straight line and the measured target position, to ensure that the measured target in the multi-camera system can be accurately projected to a unified reference line; wherein, the expression of the camera's deflection angle θ is as follows: Wherein, x1 represents the pixel width of the left light band of the second calibration block in the image captured by the camera during calibration; x2 represents the pixel width of the right light band of the second calibration block in the image captured by the camera during calibration.

4. The steel plate contour dimension measurement method based on the surface detection platform according to claim 2 or 3, characterized in that: After obtaining the resolution matrix corresponding to the camera, the method further includes: Every two adjacent cameras of the acquisition platform form a binocular stereo vision system, and multiple binocular stereo vision systems are obtained, from which two binocular stereo vision systems that are farthest apart and can capture the steel plate to be tested are selected, and are respectively recorded as the first binocular stereo vision system and the second binocular stereo vision system; Calculate the distance between the surface of the steel plate and the reference plane at a certain coordinate position under the first binocular stereo vision system and the distance between the surface of the steel plate and the reference plane at a certain coordinate position under the second binocular stereo vision system; The value of the distance between the surface of the steel plate and the reference plane at a certain coordinate position calculated by the first binocular stereo vision system and the value of the distance between the surface of the steel plate and the reference plane at a certain coordinate position calculated by the second binocular stereo vision system are combined to draw a straight line in the pixel coordinates of the two values ​​in the width direction of the measured steel plate, and the value of the distance between the surface of the steel plate and the reference plane corresponding to each pixel position of each camera along the width direction of the measured steel plate is obtained by the straight line equation and the pixel position along the width direction of the measured steel plate, and the value is used as an element to construct a matrix C; The resolution matrix corresponding to the camera is corrected using matrix C, and the corrected resolution matrix is ​​used as the final calibration result of the corresponding camera; wherein, the formula for correcting the resolution matrix corresponding to the camera is: Where E′ represents the corrected resolution matrix; E represents the original resolution matrix; n represents the number of camera pixels; f represents the focal length of the lens; and u represents the target size of the camera.

5. The steel plate contour dimension measurement method based on the surface detection platform according to claim 4, characterized in that: The calculation formula of the distance between the steel plate surface and the reference plane corresponding to the binocular stereo vision system is: In the formula, c represents the distance between the steel plate surface and the reference plane; B represents the baseline distance between the left and right cameras in the binocular stereo vision system for calculating the c value; f represents the focal length of the camera lens in the binocular stereo vision system for calculating the c value; D represents the parallax formed by the same viewpoint captured by the left and right cameras in the binocular stereo vision system to calculate the c value; H0 represents the distance from the calibration plane corresponding to the binocular stereo vision system to calculate the c value to the camera.

6. The steel plate contour dimension measurement method based on the surface detection platform according to claim 1, characterized in that: The step of calculating the outline size of the steel plate under test based on the collected surface image of the steel plate under test comprises: The light spot position in the surface image of the steel plate under test is extracted to determine the boundary pixels where the fields of view of adjacent cameras overlap, so as to determine the starting pixel and ending pixel of the steel plate area in the image captured by each camera; wherein, for the camera located at the edge of the operating side, the starting pixel of the steel plate area in the image captured by it is the pixel where the light spot position in the image is located, and the ending pixel of the steel plate area is the pixel at the edge of the operating side; for the camera located at the edge of the transmission side, the starting pixel of the steel plate area in the image captured by it is the pixel at the edge of the transmission side, and the ending pixel of the steel plate area is the pixel where the light spot position in the image is located; the starting pixel and ending pixel of the steel plate area in the images captured by the remaining cameras are the pixels where the light spot positions on both sides of the image are located respectively; Based on the calibration results of each camera and the starting and ending pixels of the steel plate area in the image captured by each camera, the length, width and coordinates of the edges of the steel plate are calculated.

7. The steel plate contour dimension measurement method based on the surface detection platform according to claim 6, characterized in that: The surface detection platform also includes a laser velocimeter; at the transverse position of the steel plate where the laser velocimeter is located, the length of the steel plate is directly output by the laser velocimeter; the length of the steel plate at other positions is calculated as follows: Count the number of all pixels along the length direction of the steel plate at the transverse position of the steel plate where the laser velocimeter is located, and divide the length of the steel plate at the transverse position of the steel plate where the laser velocimeter is located by the number of all pixels along the length direction of the steel plate at the transverse position of the steel plate where the laser velocimeter is located to obtain the longitudinal resolution; At other transverse positions of the steel plate other than the transverse position of the steel plate where the laser velocimeter is located, the length of the steel plate at the corresponding position is obtained by multiplying the number of all pixels along the length direction of the steel plate at this position by the longitudinal resolution.

8. The steel plate contour dimension measurement method based on the surface detection platform according to claim 6, characterized in that: The width W of the steel plate at the length position l l for: In the formula, sum() represents vector summation; Indicates the pixel position p corresponding to the i-th camera is ~p it The resolution matrix of the range; p is and p it Respectively represent the position coordinates of the starting pixel and the ending pixel of the steel plate area after the i-th camera removes the overlapping pixels; θ i represents the deflection angle of the i-th camera; N represents the number of cameras on the acquisition platform.

9. The steel plate contour dimension measurement method based on the surface detection platform according to claim 6, characterized in that: The operating side edge position coordinate P at the length position l of the steel plate l o for: In the formula, sum() represents vector summation; Indicates the pixel position p corresponding to camera k located at the edge of the operating side kt ~p kw The resolution matrix of the range; p kt represents the ending pixel position coordinates of the steel plate area after camera k removes the overlapping pixels; p kw represents the maximum pixel position of camera k, θ k represents the deflection angle of camera k.

10. The steel plate contour dimension measurement method based on the surface detection platform according to claim 6, characterized in that: The transmission side edge position coordinate P at the length position l of the steel plate l d for: P l d =P l o +W l Where P l o W is the edge position coordinate of the operating side at the length position l of the steel plate; l is the width of the steel plate at length position l.

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