Camera calibration system and method in galvanometer machining

Abstract

A camera calibration system and method in galvanometer machining is disclosed. The system includes a conveyor platform configured to move in a calibration direction; a gantry disposed above the conveyor platform and having a first end and a second end opposite each other in a direction perpendicular to the calibration direction; one or more cameras arranged at a desired distance from the gantry along the calibration direction and configured to capture images of a workpiece on the conveyor platform; one or more galvanometer heads disposed on the gantry and facing the conveyor platform, wherein movement of the one or more galvanometer heads between the first end and the second end of the gantry enables each of the galvanometer heads to mark 8 or more calibration points on the workpiece for each of the one or more cameras; and a controller configured to compute a correspondence between a respective camera coordinate system and a galvanometer coordinate system according to the 8 or more calibration points.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of galvanometer cutting machining, and more particularly to a camera calibration system and method in galvanometer machining. BACKGROUND

[0002] At present, the camera calibration in the galvanometer cutting machining system mostly utilizes a calibration target or utilizes a checkerboard to perform recognition calibration. However, these are in a system with complete X and Y axes, and the camera can achieve complete relative movement with the galvanometer head, so as to obtain several sets of different world coordinate values and pixel coordinate values to derive the relationship between the camera coordinate system and the galvanometer coordinate system.

[0003] However, in the scene of a conveying platform, whether linear or nonlinear, this scene is a repeated machining in a pipeline. In such a scene, there is actually no accurate Y axis, and only the corresponding X axis position can be obtained, so the traditional calibration method is not applicable to the scene of a conveying platform.

[0004] In addition, in the galvanometer machining process, an infinite field of view (IFOV) is advantageous. In order to expand the field of view of the galvanometer machining, one method is to increase the number of galvanometer heads. In this way, although the efficiency is improved, the cost is greatly increased. Another method is to use a larger platform to move the region of the workpiece to be machined under the galvanometer head. However, such a workpiece platform is relatively slow to move, and the larger the platform, the higher the cost. Moreover, the galvanometer spot moves at a uniform speed along the trajectory, while the platform movement is limited by the servo limit parameters, such as maximum jerk (derivative of acceleration), maximum acceleration, and maximum speed. Most importantly, such a larger workpiece platform is not suitable for the machining scene of a conveying platform pipeline.

[0005] Therefore, there is a need in the art for a camera calibration system and method that can be applied to the machining scene of a conveying platform. SUMMARY

[0006] In order to solve one or more of the above and / or other problems in the prior art, the present disclosure movably arranges the galvanometer head on a gantry to enable obtaining an accurate Y axis position in the machining scene of a conveying platform and to achieve IFOV infinite field of view machining of a single Y axis.

[0007] In a first aspect of the present disclosure, a camera calibration system is provided. The camera calibration system can include: a transfer platform configured to move in a calibration direction; a gantry disposed above the transfer platform and having a first end and a second end opposite to each other in a direction perpendicular to the calibration direction; one or more cameras arranged at a desired distance from the gantry along the calibration direction and configured to capture images of a workpiece on the transfer platform; one or more galvanometer heads disposed on the gantry and facing the transfer platform, wherein movement of the one or more galvanometer heads between the first end and the second end of the gantry enables each galvanometer head to mark 8 or more calibration points on the workpiece for each of the one or more cameras; and a controller configured to calculate a correspondence between a respective camera coordinate system and a galvanometer coordinate system according to the 8 or more calibration points in the images.

[0008] In one or more embodiments, the camera calibration system can include only 1 galvanometer head.

[0009] In one or more embodiments, the movement can include linear movement or non-linear movement.

[0010] In one or more embodiments, the 8 or more calibration points can be arranged randomly or regularly.

[0011] In one or more embodiments, the 8 or more calibration points can be 9 calibration points arranged in a matrix.

[0012] In one or more embodiments, the transfer platform can have a position calibrator. In a preferred embodiment, the position calibrator can be a positioning groove.

[0013] In one or more embodiments, the calculation can include: i) determining a correspondence between an image pixel coordinate system of the image and the camera coordinate system using pixel coordinates in the image coordinate system and corresponding camera coordinates in the camera coordinate system of the 8 or more calibration points in the image; and ii) determining a correspondence between the camera coordinate system and the galvanometer coordinate system using world coordinates at galvanometer cutting, world coordinates at moving into a camera field of view, and the camera coordinates of the 8 or more calibration points.

[0014] In a second aspect of the present disclosure, a camera calibration method is provided. The camera calibration method can include: (a) placing a workpiece on a conveyance platform and within a processing swath of a galvanometer head, wherein the conveyance platform can be configured to move in a calibration direction, and wherein the galvanometer head can be disposed on a gantry above and toward the conveyance platform, the gantry having a first end and a second end opposite each other in a direction perpendicular to the calibration direction; (b) marking a first calibration point on the workpiece by the galvanometer head; (c) moving the galvanometer head between the first end and the second end of the gantry; (d) marking a second calibration point on the workpiece by the galvanometer head; (e) repeating steps (c) and (d) to obtain 8 or more calibration points; (f) capturing an image of the workpiece having the 8 or more calibration points by a camera arranged at a desired distance from the gantry along the calibration direction; and (g) calculating a correspondence between a camera coordinate system and a galvanometer coordinate system according to the 8 or more calibration points in the image.

[0015] In one or more embodiments, the moving can include moving linearly or non-linearly.

[0016] In one or more embodiments, the 8 or more calibration points can be arranged randomly or regularly.

[0017] In one or more embodiments, the step (e) can further include moving the conveyance platform in the calibration direction intermittently.

[0018] In one or more embodiments, the step (e) can obtain 9 calibration points arranged in a matrix.

[0019] In one or more embodiments, the camera calibration method can further include correcting a position error of the conveyance platform with a position calibrator of the conveyance platform when the conveyance platform starts and stops.

[0020] In one or more embodiments, the position calibrator can be a positioning groove.

[0021] In one or more embodiments, the step (f) can further include identifying each of the 8 or more calibration points with a detection area bounding box.

[0022] In one or more embodiments, the step (g) can further comprise: i) determining a correspondence between an image pixel coordinate system of the image and the camera coordinate system using pixel coordinates of the 8 or more calibration points in the image coordinate system and corresponding camera coordinates; and ii) determining a correspondence between the camera coordinate system and the galvanometer coordinate system using world coordinates of the 8 or more calibration points at the time of galvanometer cutting, world coordinates at the time of moving into the field of view of the camera, and the camera coordinates.

[0023] In a third aspect of the present disclosure, a galvanometer machining system is provided. The galvanometer machining system comprises the camera calibration system as described in the first aspect above, wherein during galvanometer machining, the transfer platform is configured to move in a machining direction opposite to the calibration direction, and wherein the one or more galvanometer heads are configured to machine the workpiece based on workpiece images captured by the one or more cameras, using the correspondence between the camera coordinate system and the galvanometer coordinate system, and by moving the one or more galvanometer heads between the first end and the second end of the gantry.

[0024] In one or more embodiments, the controller can be further configured to perform an interpolation operation to compensate for movement of the workpiece along the machining direction while machining.

[0025] In a fourth aspect of the present disclosure, a computer readable storage medium is provided, having stored thereon instructions which, when executed by a processor, cause the processor to perform the steps of the method as described in the second aspect above.

[0026] Particular and preferred aspects of the present application are set out in the independent and dependent claims. Features from the dependent claims can be combined with features of the independent claims and the features of other dependent claims as appropriate and non-exclusive.

[0027] These and other aspects of the present application will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: BRIEF DESCRIPTION OF DRAWINGS

[0028] For purposes of summarizing the disclosure, certain aspects, advantages and novel features of the applications have been described above. It is to be understood that not necessarily all such advantages can be achieved in accordance with any particular embodiment. Thus, the application can be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as can be taught or suggested herein.

[0029] Figure 1 A schematic diagram of an exemplary camera calibration system according to an embodiment of the present disclosure is shown.

[0030] Figure 2 A schematic flowchart of an exemplary camera calibration method according to an embodiment of the present disclosure is shown.

[0031] Figure 3 A schematic process and results of cutting an example pattern using a galvanometer processing system according to an embodiment of the present disclosure are shown.

[0032] Figure 4 A schematic flowchart of a galvanometer cutting process according to an embodiment of the present disclosure is shown.

[0033] It is anticipated that elements in one embodiment of the invention may be advantageously adapted to other embodiments without further description. Detailed Implementation

[0034] The following describes specific embodiments of the present invention. It should be noted that, in order to provide a concise description, this specification cannot exhaustively describe all features of the actual embodiments. It should be understood that, in the actual implementation of any embodiment, just as in any engineering or design project, various specific decisions are often made to achieve the developer's specific goals and to meet system-related or business-related constraints, and this can change from one embodiment to another. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, some design, manufacturing, or production modifications based on the technical content disclosed herein are merely conventional technical means and should not be construed as insufficient content of this disclosure.

[0035] Unless otherwise defined, technical and scientific terms used in the claims and specification shall have the meaning commonly understood by one of ordinary skill in the art to which this application belongs. The use of the terms "first", "second" and like terms in the application patent specification and claims are not meant to denote any ordinal, quantity or importance, but are simply used to distinguish one element from another. The use of the terms "a" or "an" or the like in the application patent specification and claims are not meant to denote a quantity of one, but rather denote the presence of at least one. The use of the terms "include", "includes", "including" and the like in the application patent specification and claims are meant to be non-limited to the elements recited. The use of the terms "connected", "coupled", "attached" and the like in the application patent specification and claims are meant to denote either a direct connection, a direct coupling, a direct attachment, or an indirect connection, an indirect coupling, an indirect attachment, or any combination thereof.

[0036] In the present application, all the embodiments and preferred embodiments mentioned in the present application can be combined to form new technical solutions if no specific description is given. In the present application, all the technical features and preferred features mentioned in the present application can be combined to form new technical solutions if no specific description is given.

[0037] In the description of the embodiments of the present application, the term "and / or" is only used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects. In the description of the embodiments of the present application, the term "substantially no synchronization time error" means that the linkage of the mechanical shafts involved satisfies the movement of the machining head to achieve the machining accuracy.

[0038] The exemplary camera calibration system, the exemplary camera calibration method and the exemplary galvanometer machining system provided according to the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0039] Reference Figure 1 A schematic diagram of an exemplary camera calibration system 100 is shown. The camera calibration system 100 can include a conveying platform 101, such as a linear or non-linear conveyor belt. The conveying platform 101 can be configured to carry a workpiece (not shown), such as a test workpiece. The conveying platform 101 can be movable along an X-axis. In the present application, the positive direction of the X-axis can be defined as a calibration direction (X) for calibrating a camera. In addition, the negative direction of the X-axis can be defined as a machining direction (−X) for galvanometer cutting machining. In the camera calibration system 100, when it is necessary to calibrate the camera, the conveying platform 101 can be configured to move in the calibration direction (X).

[0040] In embodiments using conveyor belts, positional errors caused by slippage may occur on the conveyor platform when it starts or stops. This problem can be overcome by selecting a high-precision type of conveyor belt. In a preferred embodiment of the invention, the conveyor platform may have a position calibrator. The position calibrator may be, for example, a positioning groove.

[0041] The camera calibration system 100 may further include a gantry 102 disposed above the transport platform 101. The gantry 102 may extend along a Y-axis perpendicular to the X-axis. Figure 1 As shown, the gantry 102 may have a first end A and a second end B that are opposite to each other in the Y-axis direction.

[0042] The camera calibration system 100 may include one or more cameras 103, for example Figure 1 The cameras 103-1 and 103-2 shown are collectively referred to as camera 103. Camera 103 can be arranged at a desired distance (D) from gantry 102 along a calibrated direction (X). This distance (D) depends primarily on the speed of conveyor platform 101. Taking a conveyor belt as an example, D >= (camera exposure time + image processing time) × conveyor belt speed. Camera 103 can be configured to capture images of workpieces placed on conveyor platform 101.

[0043] The camera calibration system 100 may include one or more scanning lenses 104. For example... Figure 1 The illustrated embodiment includes only one scanning lens 104-1. This scanning lens 104-1 is shown located at the first end A of the gantry 102. However, in other embodiments, there may be two, three, four, or more scanning lenses 104. The scanning lenses 104 may be positioned (e.g., mounted) on the gantry 102 and facing the conveyor platform 101. In embodiments of the invention, the scanning lenses 104 may be movable between the first end A and the second end B of the gantry 102, such that each scanning lens 104 can mark eight or more calibration points on the workpiece located on the conveyor platform 101 for each camera 103.

[0044] exist Figure 1In the illustrated embodiment including one galvanometer head and two cameras, the galvanometer head 104-1 marks 8 or more calibration points P1, P2, P3, P4, P5, P6, P7, P8, etc. on the workpiece for camera 103-1. Meanwhile, the galvanometer head 104-1 also marks another 8 or more calibration points P1', P2', P3', P4', P5', P6', P7', P8', etc. on the workpiece for camera 103-2. In other embodiments, such as an embodiment including two galvanometer heads 104-1, 104-2 and one camera 103-1, the galvanometer head 104-1 marks 8 or more calibration points P1, P2, P3, P4, P5, P6, P7, P8, etc. on the workpiece for camera 103-1. Meanwhile, the galvanometer head 104-2 also marks another 8 or more calibration points P1', P2', P3', P4', P5', P6', P7', P8', etc. on the workpiece for camera 103-1.

[0045] In different embodiments, the galvanometer head 104 can move linearly or non-linearly. Whether linearly or non-linearly, 8 or more calibration points within the field of view of the camera are needed. The 8 or more calibration points can be arranged randomly or regularly, which does not affect the camera calibration results. For example, in one embodiment including 9 calibration points, the calibration points can be arranged in a matrix (i.e., a 3x3 matrix), but other arrangements can also be used.

[0046] The camera calibration system 100 can also include a controller (not shown). The controller is configured to calculate the correspondence between the camera coordinate system of each camera 103 and the galvanometer coordinate system of the corresponding galvanometer head based on the 8 or more calibration points in the workpiece image captured by the camera, as described in more detail below with reference to Figure 2 .

[0047] Figure 2 A schematic flowchart of an exemplary camera calibration method 200 implemented by the camera calibration system 100 is shown. The various coordinate systems involved in the camera calibration method 200 can be referred to Figure 1 , where X-Y is the world coordinate system; X cam -Y cam is the camera coordinate system; and X cut -Y cut is the cutting coordinate system of the galvanometer head, which can be understood as having its origin in the X-Y coordinate system and being movable along the Y-axis direction.

[0048] The camera calibration method 200 begins at step 210. In step 210, a workpiece can be placed on the transport platform 101 and within the working area of a galvanometer head 104 (e.g., galvanometer head 104-1).

[0049] Next, in step 220, the galvanometer head 104 can mark a first fiducial point on the workpiece. In an embodiment, the galvanometer head 104 can or can not be moved prior to marking.

[0050] After marking the first fiducial point, in step 230, the galvanometer head 104 can be moved between the first end A and the second end B of the gantry 102. Next, in step 240, the galvanometer head 104 moved to another position can mark a second fiducial point on the workpiece.

[0051] In step 250, it can be determined whether 8 or more fiducial points have been obtained. If "No", then step 230 can be returned to and further fiducial points can be marked. If "Yes", then the workpiece can be transported into the field of view of the camera for capturing, in step 260, a workpiece image having the 8 or more fiducial points by the camera 103. Then, in step 270, a correspondence between the respective camera coordinate system and the galvanometer coordinate system can be calculated from the 8 or more fiducial points in the workpiece image.

[0052] In further embodiments of the present application, intermittent movement of the transport platform 101 (and thus the workpiece disposed on the transport platform) in the indexing direction (X) can also be combined with movement of the galvanometer head 104 between the first end A and the second end B of the gantry to obtain further fiducial points. For example, in a case where movement of the galvanometer head 104 on the gantry 102 is sufficient to obtain 8 or more required fiducial points, movement of the transport platform 101 in the indexing direction (X) can not be required. For another example, in a case where movement of the galvanometer head 104 on the gantry 102 is not sufficient to obtain 8 or more required fiducial points, movement of the transport platform 101 in the indexing direction (X) after movement of the galvanometer head 104 is completed can be required to obtain further fiducial points.

[0053] For example, in the above embodiment including 9 calibration points of a 3x3 matrix, it is envisaged that, for example, the movement of the galvanometer head 104 from the first end A of the gantry 102 to the second end B can mark 3 calibration points on the workpiece, namely (xl,yl), (xl,y2) and (xl,y3), respectively. Then, after marking the calibration point (xl,y3), the transport platform 101 can be moved by a certain distance in the calibration direction (X) so that the workpiece is moved forward by the distance in the calibration direction (X) to obtain a new X-axis coordinate x2. Next, the movement of the galvanometer head 104 on the gantry 102 is continued to mark 3 new calibration points on the workpiece, namely (x2,y1), (x2,y2) and (x2,y3). After marking the calibration point (x2,y3), the workpiece is again moved by the distance in the calibration direction (X) to obtain a new X-axis coordinate x3. Then, the movement of the galvanometer head 104 on the gantry 102 is further used to mark 3 new calibration points on the workpiece, namely (x3,y1), (x3,y2) and (x3,y3), to form a 3x3 matrix of calibration points.

[0054] As mentioned above, in embodiments using a conveyor belt, a position error due to slippage can occur when the conveyor platform starts and stops. This position error can be corrected using a position corrector of the conveyor platform. The position corrector can be, for example, a positioning notch.

[0055] In embodiments, capturing an image of the workpiece with the calibration points by the camera 103 (step 260) can further comprise identifying each of the above-mentioned 8 or more calibration points using a detection area bounding box. In embodiments, calculating a correspondence between the camera coordinate system and the galvanometer coordinate system (step 270) can further comprise: i) determining a correspondence between the image pixel coordinate system and the camera coordinate system using the pixel coordinates in the image coordinate system and the corresponding camera coordinates in the camera coordinate system of the 8 or more calibration points; and ii) determining a correspondence between the camera coordinate system and the galvanometer coordinate system using the world coordinates at galvanometer cutting, the world coordinates at moving into the camera field of view and the above-mentioned camera coordinates of the 8 or more calibration points.

[0056] The camera calibration system and the camera calibration method in galvanometer machining are described above. The system and method use the movement of the galvanometer head 104 on the gantry 102 to obtain the Y-axis coordinates of the calibration points. Meanwhile, the X-axis coordinates of the calibration points can usually be obtained by the driving motor of the transport platform 101. In this way, the camera calibration system and the camera calibration method of the present application can obtain accurate coordinate positions of the calibration points in the transport platform machining scenario, thereby achieving the calibration of the camera.

[0057] Further, the present application can also obtain an infinite field of view (IFOV) for galvanometer cutting. Specifically, the two swing axes X cut and Y cut introduced by the transmission platform 101 and the Y axis introduced by the movement of the galvanometer head 104 on the gantry 102 move simultaneously, forming a four-axis system, which realizes an expanded field of view, as well as accurate positioning and high efficiency processing during movement.

[0058] During galvanometer processing after camera calibration, the above-mentioned camera calibration system can be switched to a galvanometer processing system. Among them, the transmission platform 101 can be configured to move in the processing direction (-X). At the same time, one or more galvanometer heads 104 can be configured to process the workpiece based on the workpiece image captured by one or more cameras 103, using the correspondence between the camera coordinate system and the galvanometer coordinate system obtained during the camera calibration process, and by moving one or more galvanometer heads 104 between the first end A and the second end B of the gantry 102. The galvanometer processing system of the present application can realize four-axis linkage processing using X cut -Y cut and X-Y, thereby increasing the processing area and improving the processing efficiency.

[0059] Since the transmission platform 101 continuously moves in the negative X axis direction (-X) while the galvanometer head 104 processes the workpiece, the actual pattern cut by the galvanometer head 104 will deviate from the expected pattern. In the embodiment of the present application, the four-axis linkage processing of the galvanometer processing system can perform an interpolation operation to compensate for this deviation, thereby realizing dynamic processing.

[0060] Figure 3 The schematic process and results of a galvanometer processing system using such an interpolation operation to cut an example pattern (e.g., a straight line) are shown. As shown, the left side schematically shows four different positions of a single galvanometer head 104-1 on the gantry 102. The galvanometer head 104-1 can move between these four positions. Figure 3 The middle schematically shows the galvanometer processing area corresponding to the aforementioned four positions, respectively, in which the coordinate position on the Y axis changes by ΔY from the galvanometer start point to the galvanometer end point, and the dashed line between the galvanometer start point and the galvanometer end point shows the galvanometer processing result without interpolation operation, which has a deviation ΔX from the expected straight line result. Figure 3The right side of the figure schematically shows the actual cutting result after performing the interpolation operation to compensate for ΔX, which is a straight line with a length of S1+S2. In addition, for the galvanometer cutting trajectory, the position movement distance of the galvanometer head on the Y axis is C1, the cutting movement distance of the galvanometer head itself is C2, and the actual cutting trajectory distance of the light spot is C3=C1+C2, wherein the line segment cut by C1 corresponds to S1, and the line segment cut by C2 corresponds to S2.

[0061] Reference is now made to Figure 4 A schematic flowchart of a galvanometer cutting process 400 according to embodiments of the present disclosure is shown. First, at block 410, each of the one or more galvanometer heads can be calibrated. Then, at block 420, each of the one or more cameras can be calibrated using, for example, the camera calibration method 200 described above. After the galvanometer head calibration and camera calibration, at block 430, the process can start with loading the workpiece to be processed. Next, at block 440, the galvanometer head processing can be triggered using a photoelectric switch. At block 450, the image of the workpiece to be processed can be captured by the one or more cameras described above and recognized to determine ΔX. Then, at block 460, the cutting operation with interpolation can be performed to process the workpiece. Next, at block 470, it is determined whether the processing is complete. If yes, the galvanometer cutting process ends. If no, the process returns to block 440.

[0062] One or more of the techniques and / or embodiments described above can be implemented in and / or include hardware and / or software, such as modules or devices executed on one or more electronic devices (e.g., processors). Of course, the modules or devices described herein illustrate various functions and are not limited to the structures and functions described. Rather, the functions of each module or device can be split into more or fewer modules or devices and performed by more or fewer modules or devices in various designs.

[0063] The various systems and methods described above can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0064] Some example embodiments have been described above. However, it should be understood that various modifications can be made to the above described example embodiments without departing from the spirit and scope of the present application. For example, if appropriate, suitable results can be achieved by implementing the described techniques in a different order and / or by combining components of the described systems, architectures, devices, or circuits in different ways and / or by replacing or supplementing components of the described systems, architectures, devices, or circuits with other components or their equivalents, then such modified embodiments are also within the scope of the claims.

Claims

1. A camera calibration system, characterized by, comprising: a conveyor platform configured to move in a calibration direction; a gantry disposed above the conveyor platform and having a first end and a second end opposite each other in a direction perpendicular to the calibration direction; one or more cameras arranged at a desired distance from the gantry along the calibration direction and configured to capture images of a workpiece on the conveyor platform; one or more galvanometer heads disposed on the gantry and facing the conveyor platform, wherein movement of the one or more galvanometer heads between the first end and the second end of the gantry enables each galvanometer head to mark 8 or more calibration points on the workpiece for each of the one or more cameras; and a controller configured to calculate a correspondence between a camera coordinate system and a galvanometer coordinate system from the 8 or more calibration points in the images, wherein the calculation comprises: determining a correspondence between an image pixel coordinate system of the images and the camera coordinate system using pixel coordinates in the image coordinate system and corresponding camera coordinates in the camera coordinate system of the 8 or more calibration points in the images; and determining a correspondence between the camera coordinate system and the galvanometer coordinate system using world coordinates of the 8 or more calibration points at galvanometer cutting, world coordinates at moving into a camera field of view, and the camera coordinates.

2. The camera calibration system of claim 1, wherein, The camera calibration system only includes 1 galvanometer head.

3. The camera calibration system of claim 1 or 2, wherein, The movement includes moving linearly or non-linearly.

4. The camera calibration system of claim 1 or 2, wherein, The 8 or more calibration points are arranged randomly or regularly.

5. The camera calibration system of claim 1 or 2, wherein, The 8 or more calibration points are 9 calibration points arranged in a matrix.

6. The camera calibration system of claim 1 or 2, wherein, The conveyor platform has a position calibrator.

7. The camera calibration system of claim 6, wherein, The position calibrator is a positioning groove.

8. A camera calibration method characterized by, comprising: (a) placing a workpiece on a conveyor platform and within a processing area of a galvanometer head, wherein the conveyor platform is configured to move in a calibration direction, and wherein the galvanometer head is disposed on a gantry above the conveyor platform and facing the conveyor platform, the gantry having a first end and a second end opposite each other in a direction perpendicular to the calibration direction; (b) marking a first calibration point on the workpiece by the galvanometer head; (c) moving the galvanometer head between the first end and the second end of the gantry; (d) marking a second calibration point on the workpiece by the galvanometer head; (e) repeating steps (c) and (d) to obtain 8 or more calibration points; (f) capturing an image of the workpiece with the 8 or more calibration points by a camera arranged at a desired distance from the gantry along the calibration direction; and (g) calculating a correspondence between a camera coordinate system and a galvanometer coordinate system from the 8 or more calibration points in the image, wherein the step (g) further comprises: determining a correspondence between the image pixel coordinate system of the image and the camera coordinate system using the pixel coordinates of the 8 or more calibration points in the image coordinate system and the corresponding camera coordinates; and determining a correspondence between the camera coordinate system and the galvanometer coordinate system using the world coordinates of the 8 or more calibration points when cut by the galvanometer, the world coordinates when moved into the field of view of the camera, and the camera coordinates.

9. The camera calibration method of claim 8, wherein, The moving includes moving linearly or moving non-linearly.

10. The camera calibration method of claim 8, wherein, The 8 or more calibration points are arranged randomly or regularly.

11. The camera calibration method of claim 8, wherein, The step (e) further includes moving the transport platform intermittently in the calibration direction.

12. The camera calibration method of claim 11, wherein, The step (e) obtains 9 calibration points arranged in a matrix.

13. The camera calibration method of any one of claims 8-12, wherein, Further comprising: correcting a positional error of the transport platform using a position corrector of the transport platform when the transport platform is started and stopped.

14. The camera calibration method of claim 13, wherein, The position corrector is a positioning groove.

15. The camera calibration method of claim 8, wherein, The step (f) further includes identifying each of the 8 or more calibration points using a detection area bounding box.

16. A galvanometer machining system, characterized by, A camera calibration system as claimed in any one of claims 1-7, wherein during galvanometer machining, the transport platform is configured to move in a machining direction opposite to the calibration direction, and wherein the one or more galvanometer heads are configured to machine the workpiece based on workpiece images captured by the one or more cameras, using the correspondence between the camera coordinate system and the galvanometer coordinate system, and by moving the one or more galvanometer heads between the first end and the second end of the gantry.

17. The galvanometer machining system of claim 16, wherein, The controller is further configured to perform an interpolation operation to compensate for movement of the workpiece along the machining direction while being machined.

18. A computer readable storage medium having instructions stored thereon, the instructions, when executed by a processor, causing the processor to perform the steps of the method of any one of claims 8-15.

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