Distortion correction method of flight light path and laser equipment

Abstract

The invention discloses a distortion correction method of a flight light path and laser equipment, and relates to the technical field of machine vision and laser processing. The distortion correction method for the flight light path comprises the following steps: carrying out distortion correction and proportion correction on a camera, and obtaining mapping relation data between pixel coordinates and coordinates of an actual product; determining the deviation between the center position of the camera and the center position of the flight light path according to the mapping relation data, and obtaining a relative vector of the center position of the camera relative to the center position of the flight light path; and correcting coordinates of the platform according to the relative vector. Constructing a reference position table, calculating theoretical acquisition coordinates according to the relative vector, and moving the platform to the theoretical acquisition coordinates; calculating the actual acquisition position of each sampling point, recording the optical path offset of each sampling point, and storing the optical path offset in a reference position table; and calculating the actual optical path deviation compensation amount of the target product according to the reference position table. By adopting the technology provided by the invention, the correction precision and efficiency can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical fields of machine vision and laser processing, and particularly to a distortion correction method for a flying optical path and a laser device. Background Art

[0002] In the field of laser industrial production and processing, when an XY platform carries a laser generator for a splicing processing scheme, the transmission direction of the laser beam is changed by refracting the laser through a mirror and an optical fiber. Among them, the laser generator remains stationary, and the mirror moves to form a transmission path with a specific trajectory on the working plane. Compared with moving a large-load laser generator, this method can improve space utilization. However, due to the installation of the lenses for reflecting the laser at different positions of the device, the radial, torsional, and bending deformations of the motion mechanism, and the stress deformation of the mechanical structure for fixing the lenses, it is possible to cause a change in the angle at which the laser exits onto the product surface. This pointing drift of the dynamic beam is particularly significant in large platforms or high-speed and high-acceleration motions, which will directly lead to problems such as spot position error, focus shape change, and uneven energy distribution.

[0003] Based on this, the Chinese invention patent document (CN110470220B) discloses a numerical correction method for coaxial vision deviation in a flying optical path. It corrects a single-axis flying optical path. By placing a laser-sensitive material on the laser working surface, emitting a laser to produce a visible light spot, using a camera to capture the light spot and record the offset, and then calculating the offset of any point through interpolation, it is convenient to determine the visual offset compensation function at different positions of the sliding table on the slide rail, thereby improving the accuracy of the coaxial vision system.

[0004] Although linear interpolation is used to calculate the offset in this Chinese invention patent document, it focuses on correcting the position deviation of the vision part. This makes its calculation complexity relatively large and the accuracy may be limited in complex motion mechanisms and multi-axis systems, such as the two-axis flying optical path in the XY direction and the XYZ three-axis motion proposed in this invention patent document. The optical path correction range within the entire two-dimensional or three-dimensional platform is limited. Summary of the Invention

[0005] The present invention provides a distortion correction method for a flying optical path and a laser device to solve the problem of limited optical path correction accuracy and range in a two-dimensional platform in the prior art.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is to provide a distortion correction method for a flying optical path. The distortion correction method for the flying optical path includes: performing distortion correction and scale correction on a camera so that the pixel coordinates of the image collected by the camera form a proportional mapping with the coordinates of the actual object, and obtaining the mapping relationship data between the pixel coordinates and the coordinates of the actual product.

[0007] Determine the deviation between the central position of the camera and the central position Pc of the flying optical path according to the mapping relation data, and obtain the relative vector of the central position of the camera relative to the central position of the flying optical path; correct the coordinate relative vector of the platform according to the relative vector of the central position of the camera relative to the central position of the flying optical path.

[0008] Construct a reference position table, calculate the theoretical acquisition coordinates according to the relative vector, and move the platform to the theoretical acquisition coordinates; collect the laser calibration images of each sampling point corresponding to the reference position table to calculate the actual acquisition position of each sampling point, record the optical path offset of each sampling point and store it in the reference position table; calculate the actual optical path deviation compensation amount of the target product according to the reference position table.

[0009] In some embodiments, the distortion correction and scale correction of the camera are performed so that the pixel coordinates of the image collected by the camera form a proportional mapping with the coordinates of the actual object, including: setting an optical calibration plate with a required accuracy at the central shooting position of the camera, and adjusting the acquisition parameters and light source control parameters of the camera according to the calibration features and the captured image until the captured image of the camera is clear.

[0010] Solidify the acquisition parameters and light source control parameters of the camera; perform calibration calculation on the captured image of the camera according to the optical calibration plate, including: partitioning the captured image of the camera to obtain the center distance of the image grid points of each captured image and the physical coordinates of the actual object, and calculating the deformation coefficient and scale coefficient of each partition; establish the mapping relationship between the image pixel coordinate system of the camera and the actual physical world coordinate system according to the calibration calculation result.

[0011] In some embodiments, the determination of the deviation between the central position of the camera and the central position of the flying optical path according to the mapping relation data, and the obtaining of the relative vector of the central position of the camera relative to the central position of the flying optical path, include: Set a processing identifier, where the processing identifier selects the extreme processing position of the platform; obtain the current coordinate of the platform, denoted as the first platform coordinate; move the camera so that the camera can align with the processing identifier, and when the center line of the camera completely coincides with the center image of the processing identifier, record the current coordinate of the platform as the second platform coordinate; calculate the relative vector of the central position of the camera relative to the central position of the flying optical path according to the first platform coordinate and the second platform coordinate.

[0012] In some embodiments, move the camera so that the camera can be aligned with the processing mark. When the center line of the camera completely coincides with the center image of the processing mark, record the current coordinates of the platform as the second platform coordinates, including automatic positioning, specifically: Set a circular laser mark at the set coordinate position of the platform, and move the platform according to the relative vector; the camera collects an image of the circular laser mark and calculates the deviation vector between the center of the circular laser mark and the center of the camera's field of view; adjust the position of the platform according to the deviation vector so that the center of the circular laser mark is closer to the center of the camera's field of view; iterate multiple times until the deviation vector between the center of the circular laser mark and the camera's field of view is less than the required accuracy in any direction, then determine the current coordinates of the platform as the second platform coordinates.

[0013] In some embodiments, the construction of the reference position table, calculating the theoretical acquisition coordinates according to the relative vector, and moving the platform to the theoretical acquisition coordinates includes: setting the sampling point spacing and quantity in the X direction and Y direction, recording the sampling point spacing in the X direction as DisX, the number of sampling points in the X direction as CountX, recording the sampling point spacing in the Y direction as DisY, and the number of sampling points in the Y direction as CountY.

[0014] Generate a standard two-dimensional network BaseXY, where the two-dimensional network BaseXY is a two-dimensional grid with CountX columns and CountY rows; set the first platform coordinates as Base[0,0], then the XY coordinates of the theoretical acquisition coordinates Base[m,n] of any point are:

[0015]

[0016] Among them, Psx represents the X coordinate of the first platform coordinate Ps; Psy represents the Y coordinate of the first platform coordinate Ps; Move the platform and set the laser calibration image at the theoretical acquisition coordinates Base[m,n].

[0017] In some embodiments, collecting the laser calibration images of each sampling point corresponding to the reference position table to calculate the actual acquisition position of each sampling point, recording the optical path offset of each sampling point and storing it in the reference position table includes: Calculate the actual acquisition position coordinates according to the relative vector and the theoretical acquisition coordinates Base[m,n], denoted as:

[0018] Collect the laser calibration images of the actual acquisition position coordinates AimPos(m,n) of each sampling point corresponding to the standard two-dimensional network BaseXY; calculate one by one the change of the central position in the laser calibration image of each sampling point relative to the image center position to measure the offset distance of the position of the laser calibration image relative to the theoretical acquisition coordinates, and obtain the offset amounts of each sampling point in the X direction and the Y direction; store the standard two-dimensional network BaseXY and the offset amounts of each sampling point in the X direction and the Y direction in the reference position table.

[0019] In some embodiments, the distance between adjacent sampling points in the X direction and the Y direction is greater than or equal to 20 mm to obtain the best sampling benefit.

[0020] In some embodiments, calculating the actual optical path deviation compensation amount of any target product according to the reference position table includes: calculating the reference grid including the target product according to the standard two-dimensional network BaseXY; obtaining the optical path offset amount corresponding to each vertex of the reference grid; calculating the actual optical path deviation compensation amount of the target product according to the optical path offset amount corresponding to each vertex of the reference grid.

[0021] The beneficial effects brought by the technical solution provided by the present invention compared with the prior art are: Through the above steps, it is possible to complete the optical path detection within the entire stroke (workable range) at low cost at one time, and by constructing a reference position table, the calculation complexity in the actual application process is relatively low, and it is applicable to the entire two-dimensional platform and covers the optical path correction range within all platform ranges.

[0022] Among them, in the above optical path distortion correction, there is no need to be associated with the current fixed coordinates, but coordinate dynamic modeling is performed according to the target product, that is, relative offset modeling is used instead of absolute coordinates, which improves the correction accuracy of the flying optical path while improving its versatility. In addition, the above correction process can use automated image processing to replace manual operation to avoid the interference of manual intervention to the correction accuracy.

[0023] By completing the optical path detection and correction within the entire stroke at one time, not only the accuracy and range of the optical path correction are improved, but also the production efficiency and processing quality are improved, which has significant technical and economic advantages.

[0024] In some embodiments, the present application also provides a laser device for performing the above-mentioned distortion correction method of the flying optical path. Further, the laser device includes a vision system, a motion system, a platform and a laser emission system, and the motion system is provided with a transplanting mechanism for driving the camera to move.

[0025] With the above technical solution, the laser device performs grid sampling within the entire movement range of the platform by adopting the above distortion correction method for the flying optical path, measures the optical path deviation at each sampling point, and calculates the compensation amount at any position by using bilinear interpolation. After completing the optical path detection for the entire movement range at one time, it is not necessary to perform distortion correction for each position separately, thereby improving the subsequent processing efficiency. Exemplarily, a telecentric lens and a high-precision camera can be used in the vision system and distortion correction and scale correction are performed in advance to improve the subsequent measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where: Figure 1 is a flowchart showing an embodiment of a method for correcting distortion of a flying optical path provided by the present invention; Figure 1 ; Figure 2 is a flowchart showing an embodiment of a method for correcting distortion of a flying optical path provided by the present invention; Figure 2 ; Figure 3 is an enlarged partial structural view of an embodiment of a laser device provided by the present invention; Figure 4 is a grid diagram of a method for correcting distortion of a flying optical path provided by the present invention; Figure 5 is a flowchart showing an embodiment of a method for correcting distortion of a flying optical path provided by the present invention; Figure 3 ; Figure 6 is the camera field of view of an embodiment of a method for correcting distortion of a flying optical path provided by the present invention; Figure 1 ; Figure 7 is the camera field of view of an embodiment of a method for correcting distortion of a flying optical path provided by the present invention; Figure 2 ; Figure 8 is a top view of an embodiment of a laser device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same category, and the number of objects is not limited. For example, the first object can be one or multiple.

[0029] See Figure 1 as shown Figure 1 shows a flow schematic diagram of an embodiment of a method for correcting distortion of a flying optical path provided by this application. Figure 1 .

[0030] In some embodiments, the method for correcting distortion of the flying optical path includes: Step S100, performing distortion correction and scale correction on the camera so that the pixel coordinates of the image collected by the camera form a proportional mapping with the coordinates of the actual object, and obtaining the mapping relationship data between the pixel coordinates and the coordinates of the actual product.

[0031] In some application scenarios, the camera (industrial camera) and the end-emitting laser mechanism are generally fixed in relative position. Therefore, the position of the camera is usually recordable, and the deviation between the actual position and the theoretical position can be determined by recording the movement position of the axis where the camera is located and the theoretical position of the laser processing mark collected by the camera. Therefore, to improve the accuracy of distortion correction of the flying optical path, it is also necessary to minimize the distortion caused by the camera.

[0032] Exemplarily, when the pixel coordinates of the image collected by the camera form a proportional mapping with the coordinates of the actual object (i.e., the actual physical size), the physical distance corresponding to each pixel coordinate from the center position of the camera can be calculated. Using the above-calibrated camera can meet the subsequent measurement accuracy requirements. For example, when the camera field of view is 4.2mm * 3.5mm, the resolution is 2448 * 2024, and the accuracy of the calibration board is 1um, the corrected camera can achieve a visual measurement error of ±2.5um. In some application scenarios, the visual lens of the camera can use a telecentric lens, which can further eliminate the image deformation caused by the product height fluctuation.

[0033] Step S200: Determine the deviation between the central position Ps of the camera and the central position Pc of the flight optical path according to the mapping relationship data, and obtain the relative vector Psc of the central position of the camera with respect to the central position of the flight optical path.

[0034] Combined with Figure 2 as shown in Figure 2 FIG. shows a flowchart of an embodiment of a distortion correction method for a flight optical path provided by the present application Figure 2 , including the following steps: Step S210: Set a processing identifier, where the processing identifier selects the extreme processing position of the platform.

[0035] Exemplarily, the extreme processing position can select the extreme lower left position of the platform. The main purpose of this point is to reduce the calculation difficulty. The present application does not limit this, and for example, other extreme positions of the platform can also be selected. Among them, the form of the processing identifier can select a crosshair or other easily recognizable shapes to facilitate determining the central position of the processing identifier (the central position of the current flight optical path).

[0036] Step S220: Obtain the current coordinates of the platform, denoted as the first platform coordinate Ps.

[0037] Record the precise coordinates of the platform when the processing identifier is recorded (usually provided by the control system of the platform) for subsequent calculations and calibrations, such as obtaining the first platform coordinate Ps(1, 2).

[0038] Step S230: Move the camera so that the camera can align with the processing identifier. When the center line of the camera completely coincides with the central image of the processing identifier, record the current coordinates of the platform as the second platform coordinate Pc.

[0039] Use the recorded first platform coordinate Ps and the processing identifier to perform alignment and calibration of the camera and the laser optical path. Specifically, move the camera so that the optical axis of the camera aligns with the center of the processed identifier. For example, when the center line of the camera completely coincides with the central image of the processing identifier, record the current coordinates of the platform as the second platform coordinate Pc(100, 10). Among them, the movement of the camera can be determined by the operator manually moving the camera and continuously collecting images, or can be determined by an automated device.

[0040] Step S240: Calculate the relative vector Psc of the central position of the camera with respect to the central position of the flight optical path according to the first platform coordinate Ps and the second platform coordinate Pc.

[0041] The relative vector Psc can represent the fixed offset of the camera center relative to the center of the flight optical path. That is, when the camera shooting parameters are all fixed, the relative vector Psc remains constant when the mechanical structure remains unchanged. Exemplarily, when the first platform coordinate Ps is (1, 2) and the second platform coordinate Pc is (100, 10), the relative vector Psc is calculated according to the difference between the first platform coordinate Ps and the second platform coordinate Pc as follows:

[0042] Step S300: Correct the coordinates of the platform according to the relative vector Psc. When the camera parameters are fixed, the coordinates of the platform are converted by combining the calculated fixed deviation (relative vector Psc).

[0043] Step S400: Construct a reference position table, calculate the theoretical acquisition coordinates according to the relative vector Psc, and move the platform to the theoretical acquisition coordinates.

[0044] According to the stroke range of the device movement, in order to ensure the correction of the optical path deformation in each area of the entire stroke of the device movement, in some application scenarios, it is necessary to sample the entire stroke range to construct a reference position table. Specifically, step S400 of constructing a reference position table includes: Set the sampling point spacing and quantity in the X direction and Y direction. Denote the sampling point spacing in the X direction as DisX, the number of sampling points in the X direction as CountX, denote the sampling point spacing in the Y direction as DisY, and the number of sampling points in the Y direction as CountY.

[0045] Generate a standard two-dimensional network BaseXY according to the sampling points in the X direction and the sampling points in the Y direction. Among them, the two-dimensional network BaseXY is a two-dimensional grid with CountX columns and CountY rows, which can define the positions of the sampling points to facilitate data acquisition (the offsets of each sampling point in the X direction and Y direction) and subsequent flight optical path correction calculations.

[0046] Set the first platform coordinate Ps as Base[0,0], then the XY coordinates of the theoretical acquisition coordinate Base[m,n] of any point are:

[0047]

[0048] Among them, Psx represents the X coordinate of the first platform coordinate Ps; Psy represents the Y coordinate of the first platform coordinate Ps.

[0049] Exemplarily, when DisX = 5 mm, DisY = 5 mm, CountX = 3, and CountY = 2, m and n are indices in the X and Y directions respectively. The range of m is from 0 to CountX - 1 (0 to 2); the range of n is from 0 to CountY - 1 (0 to 1). The data distribution of the constructed reference position table is shown in Table 1 below: Table 1 Schematic Diagram of Data Distribution of an Embodiment of the Reference Position Table BaseXY

[0050] By constructing the reference position table, the positions of all sampling points within the entire travel range can be systematically defined to ensure that all important areas can be covered during subsequent laser processing and vision measurement.

[0051] A moving platform is set, and the laser calibration image is set at the theoretical acquisition coordinate Base[m, n]. Exemplarily, in combination with Figure 3 as shown Figure 3 Figure 14 shows a partially enlarged schematic diagram of the structure of an embodiment of a laser device provided by the present application. Among them, the corner position coordinates of the set platform are respectively ( , ), ( , ), ( , ). The above corner positions are as indicated by the arrow marks in Figure 3 , and the above points are respectively the three extreme corner positions of the platform.

[0052] Step S500: Collect the laser calibration images of each sampling point corresponding to the reference position table to calculate the actual acquisition position of each sampling point, record the optical path offset of each sampling point and store it in the reference position table.

[0053] Calculate the actual acquisition position coordinates according to the relative vector Psc and the theoretical acquisition coordinate Base[m, n], that is, control the platform to move to the actual acquisition position AimPos. Then the current actual acquisition position can be expressed as:

[0054] Collect the laser calibration images of the actual acquisition position coordinates AimPos(m, n) of each sampling point corresponding to the standard two-dimensional network BaseXY. And calculate the change of the center position in the laser calibration image of each sampling point relative to the image center position one by one to measure the offset distance of the position of the laser calibration image relative to the theoretical acquisition coordinate, and obtain the offset amounts in the X direction and Y direction of each sampling point , record the offset amounts XY sequence. Among them, for each collected laser calibration image, image processing techniques (such as edge detection, morphological operations, etc.) can be used to automatically calculate the center position of the identifier in the image, which will not be elaborated here.

[0055] Store the standard two-dimensional network BaseXY and the offsets of each sampling point in the X and Y directions in the reference position table. Then the reference position table can contain multiple sampling points of multiple two-dimensional networks BaseXY, and each sampling point also contains the corresponding platform coordinates (X, Y), as well as the offsets of each measured sampling point in the XY direction .

[0056] Step S600, calculate the actual optical path deviation compensation amount of the target product according to the reference position table.

[0057] Exemplarily, combined with Figure 4 shown, Figure 4 a grid schematic diagram of a distortion correction method for a flying optical path provided by the present application is shown.

[0058] The actual transformed offsets corresponding to each sampling point have been stored in the reference position table for compensation. Then, in some application scenarios, according to the standard two-dimensional network BaseXY, the reference grid containing the current target product can be determined, that is, four sampling points located on the periphery of the coordinates of the target product in the reference position table are obtained.

[0059] Obtain the optical path offsets t corresponding to the four sampling points of the reference grid. Calculate the actual optical path deviation compensation amount of the target product according to the optical path offsets t corresponding to each vertex of the reference grid.

[0060] Exemplarily, according to the known compensation data of the four vertices corresponding to the grid, the optical path offset corresponding to the target product coordinates can be calculated using bilinear interpolation . As Figure 4 shown, the compensation data extracted from the four vertices of the two-dimensional network BaseXY are: , , , , then use the bilinear interpolation formula to calculate the compensation amount of the target product coordinates as:

[0061] Among them, , represents the ratio of the target product in the X direction relative to the two-dimensional grid, represents the ratio of the target product in the Y direction relative to the two-dimensional grid.

[0062] In summary, through the above steps, the optical path detection within the entire travel (workable range) can be completed at low cost. By constructing a reference position table, the computational complexity during actual application is relatively low, and it is applicable to the entire two-dimensional platform and covers the optical path correction range within all platform ranges.

[0063] Among them, in the above optical path distortion correction, it is not necessary to be associated with the current fixed coordinates. Instead, coordinate dynamic modeling is performed based on the target product, that is, relative offset modeling is used to replace absolute coordinates, which improves the correction accuracy of the flying optical path and also improves its versatility. In addition, the above correction process can use automated image processing to replace manual operations to avoid the interference of manual intervention on the correction accuracy.

[0064] In some embodiments, the distance between adjacent sampling points in the X direction and the Y direction is greater than or equal to 20 mm. Since in the actual sampling process, the higher the density, the more measurement data there will be. Although the corrected values have high accuracy, it takes too long and requires high precision for the measurement equipment, vision system, and motion system. In some application scenarios, since currently the laser emitter and vision system, etc. are mainly driven by linear motors, and when the linear motor is within a 20-mm moving range, its deformation amount is less than 2 μm. At the same time, the accuracy of the motion system and vision system is usually also less than 2 μm. Therefore, in the actual sampling process, too high a sampling density will not obtain higher beneficial effects. Setting the sampling density of adjacent sampling points in the X direction and the Y direction to be limited to 20 mm will result in higher benefits.

[0065] In some embodiments, in combination Figure 5 as shown Figure 5 shows a flowchart of an embodiment of a method for correcting the distortion of a flying optical path provided by the present application Figure 3 . The step S100 of performing distortion correction and scale correction on the camera may include: Step S110: Set an optical calibration board with a required accuracy at the central shooting position of the camera, and adjust the acquisition parameters and light source control parameters of the camera according to the calibration features and the captured image until the captured image of the camera is clear.

[0066] Exemplarily, camera acquisition parameters such as exposure, gamma value, contrast, and brightness gain, as well as the voltage value of the light source controller, etc., will all affect the final imaging effect of the camera, that is, it will cause the position of the recognized calibration board lines to shift. Therefore, the above optical calibration board is a checkerboard calibration board or a grid calibration board or a dot calibration board.

[0067] Among them, the calibration process is to establish a radial distortion model and a tangential distortion model, obtain the coefficients of radial distortion and tangential distortion, and combine them into distortion coefficients, which will not be elaborated here.

[0068] Step S120, solidify the acquisition parameters and light source control parameters of the camera.

[0069] The internal parameters of the camera, including the focal length and the optical center, can be used to create a camera matrix, which is used to eliminate the distortion caused by a specific camera lens. And this camera matrix is unique for a specific camera and can be reused on other images taken by the same camera (with unchanged parameters).

[0070] Step S130, perform calibration calculations on the acquired images of the camera according to the optical calibration board, including.

[0071] Exemplarily, the actual size and coordinates of each color block in the physical world can be determined according to the specifications of the calibration board. According to the vision algorithm, the acquired images of the camera are partitioned to obtain the center distance of the image grid points (pixels) of each acquired image and the physical distance of the actual object (the unit is generally mm), and then the deformation coefficient and the scale coefficient corresponding to each partition can be calculated.

[0072] Step S140, establish the mapping relationship between the image pixel coordinate system and the actual physical world coordinate system of the camera according to the calibration calculation results.

[0073] When the coordinates corresponding to the known corresponding points (such as specific points on the checkerboard calibration board) in the physical world and the pixel coordinates in the acquired image are known, the deformation coefficient and the scale coefficient corresponding to each partition can be calculated through the continuous calibration process of the camera. That is, the distortion coefficient, and then the mapping relationship data between the pixel coordinates and the actual physical size can be obtained.

[0074] In some embodiments, in step S230, move the camera so that the camera can align with the processing mark. When the center line of the camera completely coincides with the center image of the processing mark, record the current coordinate of the platform as the second platform coordinate Pc, including automatic positioning, including: Set a circular laser mark at the set coordinate position Pm of the platform. Exemplarily, in combination with a specific metal material, a circular mark point with clear edges can be obtained. Move the platform to a new position according to the relative vector Psc. Among them, usually, the absolute value of the position change caused by the structural deformation range is less than 1 mm. Therefore, after the platform moves, the circular laser mark at the previous position can still be observed at the new position.

[0075] The camera captures an image of the circular laser mark and calculates the deviation vector between the center of the circular laser mark and the center of the camera's field of view. The position of the platform is adjusted according to the deviation vector so that the center of the circular laser mark is closer to the center of the camera's field of view. Exemplarily, in combination with Figures 6 to 7 as shown Figure 6 Figure 4 shows the camera field of view of an embodiment of a distortion correction method for a flying optical path provided by the present application Figure 1 ; Figure 7 Figure 5 shows the camera field of view of an embodiment of a distortion correction method for a flying optical path provided by the present application Figure 2 , where Figure 7 is Figure 6 an enlarged schematic view.

[0076] As Figure 6 and Figure 7 shown, the intersection point of the scale lines is the center of the camera's field of view. The deviation vector of the center position of the black dot pattern of the circular laser mark relative to the camera center is as shown in the upper left corner of Figure 7 , X = 0.01619, Y = 0.00510, where R = 0.155033. Then the deviation vector can be (0.01619, 0.000510). After multiple iterations until the deviation vector between the center of the circular laser mark and the camera field of view is less than the required accuracy in any direction, the current coordinates of the platform are determined as the second platform coordinates Pc.

[0077] Referring to Figure 8 as shown Figure 8 Figure 6 shows a top view of an embodiment of a laser device provided by the present application.

[0078] In some embodiments, the present application also provides a laser device for performing the above-mentioned distortion correction method for a flying optical path. It includes a vision system 10, a motion system 20, a platform 30, and a laser emission system 40. The motion system 20 is provided with a transplant mechanism 21 for driving the camera to move.

[0079] In the embodiment of the present application, the laser device shows a flying optical path (as shown by the black shaded part in Figure 8 ). By using the above-mentioned distortion correction method for the flying optical path to perform grid sampling within the entire motion range of the platform, measuring the optical path deviation at each sampling point, and using bilinear interpolation to calculate the compensation amount at any position. After completing the optical path detection of the entire motion range at one time, there is no need to perform distortion correction on each position separately, improving the subsequent processing efficiency. Exemplarily, a telecentric lens and a high-precision camera can be used in the vision system 10 and pre-distortion correction and scale correction can be performed in advance to improve the subsequent measurement accuracy.

[0080] The above are only the embodiments of the present invention, and do not thereby limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall fall within the protection scope of the present invention.

Claims

1. A method for correcting distortion of a flying optical path, characterized in that Including: Performing distortion correction and scale correction on the camera so that the pixel coordinates of the image collected by the camera form a proportional mapping with the coordinates of the actual object, and obtaining the mapping relationship data between the pixel coordinates and the coordinates of the actual product; Determining the deviation between the central position of the camera and the central position of the flight optical path according to the mapping relationship data, and obtaining the relative vector of the central position of the camera relative to the central position of the flight optical path; Correcting the coordinates of the platform according to the relative vector of the central position of the camera relative to the central position of the flight optical path; Constructing a reference position table, calculating the theoretical acquisition coordinates according to the relative vector, and moving the platform to the theoretical acquisition coordinates; Collecting laser calibration images of each sampling point corresponding to the reference position table to calculate the actual acquisition position of each sampling point, recording the optical path offset of each sampling point and storing it in the reference position table; Calculating the actual optical path deviation compensation amount of the target product according to the reference position table.

2. The distortion correction method for the flight optical path according to claim 1, wherein The performing distortion correction and scale correction on the camera so that the pixel coordinates of the image collected by the camera form a proportional mapping with the coordinates of the actual object includes: Setting an optical calibration board with a required accuracy at the central shooting position of the camera, and adjusting the acquisition parameters and light source control parameters of the camera according to the calibration features and the captured image until the captured image of the camera is clear; Solidifying the acquisition parameters and light source control parameters of the camera; Performing calibration calculation on the captured image of the camera according to the optical calibration board, including: partitioning the captured image of the camera to obtain the center distance of the image grid points of each captured image and the physical coordinates of the actual object, and calculating the deformation coefficient and scale coefficient of each partition; Establishing the mapping relationship between the image pixel coordinate system and the actual physical world coordinate system of the camera according to the calibration calculation result.

3. The distortion correction method for the flight optical path according to claim 1, characterized in that The determining the deviation between the central position of the camera and the central position of the flight optical path according to the mapping relationship data, and obtaining the relative vector of the central position of the camera relative to the central position of the flight optical path includes: Setting a processing identifier, where the processing identifier selects the limit processing position of the platform; Obtaining the current coordinates of the platform, denoted as the first platform coordinates; Moving the camera so that the camera can align with the processing identifier. When the center line of the camera completely coincides with the center picture of the processing identifier, record the current coordinates of the platform as the second platform coordinates; Calculating the relative vector of the central position of the camera relative to the central position of the flight optical path according to the first platform coordinates and the second platform coordinates.

4. The distortion correction method for the flight optical path according to claim 3, wherein Moving the camera so that the camera can align with the processing identifier. When the center line of the camera completely coincides with the center picture of the processing identifier, recording the current coordinates of the platform as the second platform coordinates includes automatic positioning, specifically: Setting a circular laser identifier at the set coordinate position of the platform; Moving the platform according to the relative vector of the central position of the camera relative to the central position of the flight optical path; The camera acquires an image of the circular laser marker and calculates the deviation vector between the center of the circular laser marker and the center of the camera's field of view; Adjust the position of the platform according to the deviation vector so that the center of the circular laser marker is closer to the center of the camera's field of view; Iterate multiple times until the deviation vector between the center of the circular laser marker and the camera's field of view is less than the required accuracy in any direction, and then determine the current coordinates of the platform as the second platform coordinates.

5. The distortion correction method for a flying optical path according to claim 1, wherein The construction of the reference position table, the calculation of the theoretical acquisition coordinates according to the relative vector, and the movement of the platform to the theoretical acquisition coordinates include: Set the sampling point spacing and quantity in the X direction and Y direction. Denote the sampling point spacing in the X direction as DisX, the number of sampling points in the X direction as CountX, the sampling point spacing in the Y direction as DisY, and the number of sampling points in the Y direction as CountY; Generate a standard two-dimensional network BaseXY, where the two-dimensional network BaseXY is a two-dimensional grid with CountX columns and CountY rows; Set the first platform coordinates as Base[0,0], then the XY coordinates of the theoretical acquisition coordinates Base[m,n] of any point are: where Psx represents the X coordinate of the first platform coordinates; Psy represents the Y coordinate of the first platform coordinates; Move the platform and set the laser calibration image at the theoretical acquisition coordinates Base[m,n].

6. The method for correcting distortion of a flight optical path according to claim 5, wherein, The acquisition of the laser calibration images of each sampling point corresponding to the reference position table to calculate the actual acquisition position of each sampling point, record the optical path offset of each sampling point and store it in the reference position table, including: Calculate the actual acquisition position coordinates according to the relative vector and the theoretical acquisition coordinates Base[m,n], denoted as: Among them, represents the actual acquisition position coordinates, Base[m,n] represents the theoretical acquisition coordinates, and Psc represents the relative vector of the central position of the camera relative to the central position of the flight optical path; Acquire the laser calibration images of the actual acquisition position coordinates AimPos(m,n) of each sampling point corresponding to the standard two-dimensional network BaseXY; Calculate the change of the center position in the laser calibration image of each sampling point relative to the image center position one by one to measure the offset distance of the position of the laser calibration image relative to the theoretical acquisition coordinates, and obtain the offset amounts of each sampling point in the X direction and Y direction; Store the standard two-dimensional network BaseXY and the offset amounts of each sampling point in the X direction and Y direction in the reference position table.

7. The distortion correction method for the flight optical path according to any one of claims 5 or 6, characterized in that The spacing between adjacent sampling points in the X direction and Y direction is greater than or equal to 20 mm.

8. The distortion correction method for the flight optical path according to any one of claims 1 to 6, characterized in that The calculation of the actual optical path deviation compensation amount of any target product according to the reference position table includes: Calculate the reference grid containing the target product according to the standard two-dimensional network BaseXY; Obtain the optical path offset corresponding to each vertex of the reference grid; Calculate the actual optical path deviation compensation amount of the target product according to the optical path offset corresponding to each vertex of the reference grid.

9. A laser device, characterized in that, For performing the distortion correction method of the flying optical path according to any one of claims 1 to 8.

10. The laser device according to claim 9, characterized in that, The laser device includes: a vision system, a motion system, a platform, and a laser emission system, and the motion system is provided with a transplanting mechanism for driving the camera to move.

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