A camera fast calibration method and device for a laser line-based double-edge cutting system

Abstract

The application discloses a kind of based on laser line's double side cutting system camera fast calibration method, comprising: multiple industrial cameras, first laser source, second laser source, first laser source is fixedly arranged above the first side of roll table, second laser source is set to be movable between the first side and the second side of roll table;Detect that steel plate is transported to centering area, obtain steel plate specification information, second laser source continuously scans from the first side to the second side and finally stays in target cutting edge position, multiple steel plate images are continuously obtained by industrial camera in scanning process;Based on algorithm, the pixel position of laser line in multiple steel plate images is identified to carry out pixel calibration, pixel position is mapped with physical position to form mapping relationship, and actual calibration data is generated based on mapping relationship.The application further provides a kind of fast calibration device.The application realizes the automatic calibration of steel plate, solves the cumbersome camera calibration of automatic centering system of plate, large amount of data, and the problem that later verification is cumbersome.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machine vision application technology, and in particular to a camera rapid calibration method and device for a double-sided shear system based on a laser line. BACKGROUND

[0002] At present, the shearing of a domestic double-sided shear is gradually upgraded from manual operation to a mode of realizing centering through visual detection, which is becoming more and more popular, and the calibration of a camera is an important link, which directly affects the success or failure of centering. For plate production, orders are often made, and the specifications of steel plates are various. The camera is fixedly installed, and the pixel values of steel plates of different widths and thicknesses occupy different pixels in the image. Therefore, the steel plates of different thicknesses must be calibrated in the image to meet the process requirements, which leads to a complex calibration procedure, a large workload, and difficulty in ensuring accuracy. Meanwhile, the camera of the double-sided shear station has a large coverage range and high accuracy, and the camera often has serious distortion, resulting in a large deviation of pixel values at different positions. With the use of the equipment, the position of the camera may change due to vibration or loosening, causing a large change in the size in the image, and thus leading to the failure of centering, shearing waste, and the like.

[0003] Therefore, there is a need for improvement in the existing technology of the camera rapid calibration method for the automatic centering system of the double-sided shear. SUMMARY

[0004] Therefore, the present application aims to provide a camera rapid calibration method and device for a double-sided shear system based on a laser line to solve the problems of a large workload, complicated calibration, and rapid verification in the later period.

[0005] To achieve the above-mentioned purpose, the present application provides a camera rapid calibration method for a double-sided shear system based on a laser line, which comprises the following steps:

[0006] A plurality of industrial cameras, a first laser source, and a second laser source are installed above a roller way of an automatic centering system of a double-sided shear. The first laser source is fixedly arranged above a first side edge of the roller way, and the second laser source is arranged to be movable between the first side edge and a second side edge of the roller way.

[0007] When a steel plate is transported to a centering area, the specification information of the steel plate is acquired, the second laser source is continuously scanned from the first side edge to the second side edge and finally stays at a target cutting edge position, and a plurality of steel plate images are continuously acquired by the industrial cameras during the scanning process.

[0008] The pixel positions of the laser lines in the plurality of steel plate images are recognized based on an algorithm to perform pixel calibration, the pixel positions are mapped with physical positions to form a mapping relationship, and actual calibration data is generated based on the mapping relationship.

[0009] In some embodiments, the physical position is generated based on the steel plate specification information and the relative position relationship of the first laser source and the second laser source.

[0010] In some embodiments, the pixel position of the laser line in the steel plate image is identified based on an algorithm for pixel calibration, which comprises:

[0011] The laser line position of the first laser source is defined as the origin pixel position, the moving pixel position of the laser line emitted by the second laser source in each steel plate image is identified by a straight line extraction algorithm, and the pixel calibration is performed based on the origin pixel position and the moving pixel position.

[0012] In some embodiments, the laser line projection position of the first laser source coincides with the double-side shear opening, the second laser source is installed on a servo linear module, the servo linear module is controlled by a PLC controller to move to drive the second laser source to move, and when the opening position moves, the final position of the laser line is controlled by the PLC controller to always coincide with the opening position.

[0013] In some embodiments, the actual calibration data comprises the thickness and width of the steel plate.

[0014] In some embodiments, the pixel position, mapping relationship and actual calibration data of each steel plate are stored in the calibration database in real time.

[0015] In some embodiments, the industrial cameras are two, the shooting range of the two industrial cameras covers at least the double-side area of the steel plate, the pixel position of the laser line in the multiple steel plate images is identified based on an algorithm for pixel calibration, and when the pixel position is mapped with the physical position, the steel plate area that cannot be covered by the camera adopts linear mapping.

[0016] Another aspect of the embodiment of the present application provides a camera rapid calibration device of a double-side shear system based on a laser line, which comprises:

[0017] The gantry comprises a cross beam arranged parallel to the roller and a plurality of columns, and the plurality of columns are connected between the cross beam and the roller;

[0018] The plurality of industrial cameras are installed on the cross beam at intervals to obtain the steel plate images on the roller;

[0019] The laser module comprises a first laser source, a second laser source and a servo linear module, the first laser source is fixed on the cross beam, and the second laser source is installed on the servo linear module and is slidably fixed on the cross beam;

[0020] The computer control module is in communication connection with the plurality of industrial cameras and the laser module to obtain data and perform calibration based on the data.

[0021] In some embodiments, the computer control module includes a PLC controller connected with the first laser source, the second laser source and the servo linear module, and a computer processor connected with the PLC controller and the plurality of industrial cameras to acquire data and calibrate based on the data.

[0022] In some embodiments, the second laser source is movable between the first side edge and the second side edge of the roller table in a width direction of the roller table.

[0023] The present application has at least the following beneficial technical effects:

[0024] The present application provides a rapid calibration method and device, by setting a fixed laser source and a moving laser source to move with the shearing knife edge of different steel plates, and continuously capturing laser lines by industrial cameras, the influence of lens distortion is effectively avoided by continuously shooting at multiple positions during the movement of the laser lines, and the laser lines are directly extracted as calibration standards by image processing algorithms to realize automatic calibration of the steel plates, solving the problems of complicated camera calibration, large amount of data, influence on production and complicated post verification of the automatic centering system of the heavy plate. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other embodiments can be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 The flowchart of the embodiment of the rapid camera calibration method based on the laser line of the double-sided shearing system provided by the present application is shown in the figure.

[0027] Figure 2 The schematic diagram of the embodiment of the rapid camera calibration device based on the laser line of the double-sided shearing system provided by the present application is shown in the figure.

[0028] Explanation of reference signs:

[0029] 1, gantry; 2, industrial camera; 3, laser module; 4, steel plate; 5, roller table;

[0030] 10, cross beam, 11, stand; 30, first laser source; 31, second laser source; 32, servo linear module; 50, first side edge; 51, second side edge. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will be further described in detail with specific embodiments and with reference to the drawings.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. For example, the terms "length", "width", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, merely describe the orientation in the drawings on which the present application can be directed, and are not intended to be limiting.

[0033] The terms "comprise", "comprising", "include", "including", "have" and "having" and any variations thereof in the specification and in the claims are intended to cover both the singular and the plural unless otherwise indicated; the terms "first", "second", and the like in the description and in the claims are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. The term "multiple" means two or more, unless explicitly stated otherwise.

[0034] In the specification and the claims of the application and the above description of the drawings, when an element is referred to as being "fixed to" or "attached to" or "disposed on" or "connected to" another element, it can be directly or indirectly on or connected to the other element. For example, when an element is referred to as being "connected to" another element, it can be directly or indirectly connected to the other element.

[0035] In addition, reference herein to "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to those of ordinary skill in the art upon reading this description, the embodiments described herein are merely examples of implementations and are not intended to limit the scope of the application in any way.

[0036] As Figure 1 A laser line-based camera rapid calibration method for a double-sided shearing system is provided, and the method comprises the following steps:

[0037] S1, multiple industrial cameras, a first laser source and a second laser source are installed above a roller way of a double-sided shearing automatic centering system, the first laser source is fixedly arranged above a first side edge of the roller way, and the second laser source is arranged to be movable between the first side edge and a second side edge of the roller way;

[0038] S2, the steel plate is detected to be transported to a centering area, steel plate specification information is acquired, the second laser source is continuously scanned from the first side edge to the second side edge, and multiple steel plate images are continuously acquired by the industrial cameras during the scanning process;

[0039] S3, pixel calibration is performed on the pixel positions of the laser lines in the plurality of steel plate images based on an algorithm, a mapping relationship is formed by mapping the pixel positions to physical positions, and actual calibration data is generated based on the mapping relationship.

[0040] Further, in S1, the first laser source is a fixed laser source, and the position of the laser line emitted by the first laser source is arranged to be aligned with one side of the centering area. The second laser source is a movable laser source, and the moving position of the second laser source can be between the first side and the second side of the roller, or the second laser source can be arranged to move linearly in the centering area, so that the laser line emitted by the second laser source can coincide with the position of the cutting edge of the double-side shear. In the present application, the first side and the second side of the roller are two sides in the width direction of the roller. Figure 2 As shown in the figure, the industrial camera only captures the double-side area. In order to reduce the production cost as much as possible, the image of the middle part of the steel plate can not be directly obtained, and the position can be obtained through subsequent algorithm processing.

[0041] Further, in S2, after detecting that the steel plate is transported to the centering area, the computer control module first obtains the specification parameter information of the steel plate, and then the second laser source is continuously scanned from the first side to the second side and finally stays at the target cutting edge position. In some embodiments of the present application, the projection position of the laser line of the first laser source coincides with the cutting edge of the double-side shear, the second laser source is installed on a servo linear module, the servo linear module is controlled by a PLC controller to move to drive the second laser source to move, and when the cutting edge position moves, the laser line is controlled by the PLC controller to move and finally stays at the position coinciding with the cutting edge position.

[0042] Further, in S3, the projection position of the laser line of the first laser source is defined as the origin pixel position, the moving pixel position of the laser line emitted by the second laser source in each steel plate image is identified by a straight line extraction algorithm, pixel calibration is performed based on the origin pixel position and the moving pixel position, and when the pixel position is mapped to the physical position, the linear mapping is adopted for the steel plate area that cannot be covered by the camera. In addition, during the movement of the laser source, the computer control module can obtain the relative position between the two laser sources, generate the physical position based on the specification information of the steel plate and the relative position relationship between the first laser source and the second laser source, map the pixel position to the physical position to form a mapping relationship, and generate actual calibration data based on the mapping relationship. The final calibration data includes the thickness and width information of the steel plate. In some embodiments, the pixel position, the mapping relationship and the actual calibration data of each steel plate are stored in a calibration database in real time.

[0043] The present application also provides a camera rapid calibration device for a double-side shear automatic centering system based on a laser line, which is applied to implement the above method. The device comprises:

[0044] The gantry 1 comprises a cross beam 10 arranged parallel to the roller way and a plurality of columns 11 connected between the cross beam 10 and the roller way 5;

[0045] A plurality of industrial cameras 2 are installed on the cross beam 10 at intervals to acquire images of the steel plate on the roller way 5;

[0046] A laser module 3 comprises a first laser source 30, a second laser source 31 and a servo linear module 32, the first laser source 30 is fixed on the cross beam 10, the second laser source 31 is installed on the servo linear module 32 and is slidably fixed on the cross beam 10, and the moving range of the second laser source is movable between the first side edge and the second side edge of the roller way in the width direction of the roller way;

[0047] A computer control module (not shown in the figure) comprises a PLC controller and a computer processor, wherein the PLC controller is in communication connection with the plurality of industrial cameras 2 and the laser module 3 to realize control, and the computer processor acquires data and calibrates based on the data. The application will be further explained through specific embodiments.

[0048] A plurality of industrial cameras, a first laser source and a second laser source are installed above the roller way of the bilateral shearing automatic centering system, the first laser source is fixedly arranged above the first side edge of the roller way, and the second laser source is arranged to be movable between the first side edge and the second side edge of the roller way;

[0049] The roller way is manually controlled to run, so that the steel plate is stopped between the gantries, and the computer acquires the specification information of the steel plate;

[0050] The PLC controls the servo linear module to move the second laser from the initial position to the position of the cutting edge width required to be sheared, and the industrial camera continuously collects image information data of the steel plate during the movement and transmits the data to the data computer server.

[0051] The computer server processes the image data through an algorithm program, automatically extracts the positions of the laser lines, calculates the number of pixel points between the laser lines, and simultaneously accurately acquires the actual distance of the laser lines according to the actual position of the servo linear module, through a calibration algorithm, the mapping of the pixel distance and the actual distance can be obtained, and is automatically stored in a calibration database.

[0052] Finally, the above steps are repeated to calibrate the steel plate of other thickness specifications.

[0053] The method of the present application can realize on-line production and calibration, and for the first time encountered steel plate specification, can realize direct on-line production, on-line calibration, and when on-line production is not allowed to continuously mark or stop, the above steps can be used to complete the marking of the corresponding cutting specification, and then the information just marked is directly called to identify the specific position of the steel plate, and the centering control algorithm is called to realize the control of automatic centering.

[0054] The calibration laser line can be used as a reference for manual auxiliary judgment of whether the steel plate is centered, replacing the line laser currently installed on the double-sided shear equipment, solving the problems that the line laser is difficult to realize two-side parallelism, has large error, small laser energy, and wide tail laser width, which causes the operator to be unable to accurately judge whether the steel plate is centered.

[0055] The above is the exemplary embodiment disclosed by the present application, but it should be noted that various changes and modifications can be made without departing from the scope of the embodiments disclosed by the present application defined by the claims. The functions, steps and / or acts of the method claims described herein need not be performed in any particular order. Furthermore, although the elements of the embodiments disclosed by the present application can be described or claimed in individual form, unless explicitly restricted, they can also be implemented in multiple forms.

[0056] It should be understood that, as used herein, the singular forms "a", "an" and "the" are intended to include plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0057] The above embodiment number of the embodiments disclosed by the present application is only for description, and does not represent the advantages and disadvantages of the embodiments.

[0058] Those skilled in the art should understand that the above discussion of any embodiment is only exemplary, and is not intended to limit the scope of the embodiments disclosed by the present application (including claims) to these examples; under the idea of the embodiments of the present application, the technical features of the above embodiments or different embodiments can also be combined, and there are many other changes of the different aspects of the embodiments of the present application as above. In order to be brief, they are not provided in details. Therefore, any omissions, modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. A laser line based bilateral shearing system camera fast calibration method, characterized in that, The method comprises the following steps: A plurality of industrial cameras, a first laser source and a second laser source are installed above the roll table of the automatic centering system of the double-sided shears, the first laser source is fixedly arranged above the first side edge of the roll table, and the second laser source is arranged to be movable between the first side edge and the second side edge of the roll table; When the steel plate is transported to the centering area, the specification information of the steel plate is acquired, the second laser source is continuously scanned from the first side edge to the second side edge and finally stays at the target cutting edge position, and a plurality of steel plate images are continuously acquired by the industrial cameras during the scanning process; The pixel positions of the laser lines in the plurality of steel plate images are identified based on an algorithm to perform pixel calibration, the pixel positions are mapped with the physical positions to form a mapping relationship, and actual calibration data is generated based on the mapping relationship.

2. The laser-line-based double-edge-trimmer system camera fast calibration method according to claim 1, wherein, The physical positions are generated based on the specification information of the steel plate and the relative position relationship of the first laser source and the second laser source.

3. The laser-line-based double-edge-trimmer system camera fast calibration method of claim 1, wherein, The pixel positions of the laser lines in the steel plate images are identified based on an algorithm to perform pixel calibration, which comprises the following steps: The laser line position of the first laser source is defined as the origin pixel position, the moving pixel positions of the laser lines emitted by the second laser source in each steel plate image are identified by a straight line extraction algorithm, and pixel calibration is performed based on the origin pixel position and the moving pixel position.

4. The laser-line-based double-edge-trimmer system camera fast calibration method of claim 1, wherein, The laser line projection position of the first laser source coincides with the cutting edge of the double-sided shears, the second laser source is installed on a servo linear module, the movement of the servo linear module is controlled by a PLC controller to drive the movement of the second laser source, and when the cutting edge position moves, the final position of the laser line is controlled by the PLC controller to coincide with the cutting edge position.

5. The laser-line-based double-edge-trimmer system camera fast calibration method of claim 1, wherein, The actual calibration data includes the thickness and width of the steel plate.

6. The laser-line-based double-edge-trimmer system camera fast calibration method of claim 1, wherein, The pixel positions, the mapping relationship and the actual calibration data of each steel plate are stored in a calibration database in real time.

7. The laser-line-based double-edge-trimmer system camera fast calibration method of claim 1, wherein, There are two industrial cameras, the shooting range of the two industrial cameras covers at least the double-side area of the steel plate, the pixel positions of the laser lines in the plurality of steel plate images are identified based on an algorithm to perform pixel calibration, and when the pixel positions are mapped with the physical positions, the steel plate area that cannot be covered by the camera adopts linear mapping.

8. A laser-line-based automatic centering system camera fast calibration device for double-edge shears, said device being used to implement the method according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: A portal frame, which comprises a cross beam arranged parallel to the roll table and a plurality of columns connected between the cross beam and the roll table; A plurality of industrial cameras are installed on the cross beam at intervals to acquire steel plate images on the roll table; A laser module, which comprises a first laser source, a second laser source and a servo linear module, the first laser source is fixed on the cross beam, and the second laser source is installed on the servo linear module and slidably fixed on the cross beam; A computer control module is in communication connection with the plurality of industrial cameras and the laser module to acquire data and perform calibration based on the data.

9. The laser-line-based, double-edge-trimmer automatic alignment system camera quick-calibration apparatus of claim 8, wherein, The computer control module comprises a PLC controller and a computer processor, the PLC controller is connected with the first laser source, the second laser source and the servo linear module, and the computer processor is connected with the PLC controller and the plurality of industrial cameras to acquire data and perform calibration based on the data.

10. The laser-line-based, double-edge shear automatic alignment system camera quick calibration apparatus of claim 8, wherein, The second laser source is movable in a width direction of the roller table between a first side edge and a second side edge of the roller table. The second laser source is movable in a width direction of the roller table between a first side edge and a second side edge of the roller table.

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