A double-sided drilling positioning device and method based on opposite double-camera visual positioning

Abstract

The application discloses a kind of based on opposite double camera vision relocation's double-face drilling positioning device and method.The device includes processing equipment, displacement table, first five-axis adjustment system, first camera equipment, second camera equipment, second five-axis adjustment system and control system;First camera equipment and second camera equipment are respectively set in the opposite sides of material to be processed, and form common optical axis by coaxial alignment.The method includes: determining the relative position relationship of common optical axis and processing axis, positioning and carrying out first section processing to target hole position before turning over by first camera equipment;After turning over, the corresponding position of first hole section is identified by second camera equipment, according to hole type, hole center secondary positioning, in-plane rotation angle correction and / or mirror image path correction is carried out, then it is moved to processing axis to carry out second section processing, so that two hole sections are connected to form through hole.The scheme can reduce the influence of turning over clamping error and mechanical reference error on double-face drilling connection accuracy.

Description

Technical Field

[0001] This invention relates to the fields of machining positioning, visual inspection and automation control technology, and specifically to a double-sided drilling positioning device and method based on opposing dual-camera visual repositioning.

[0002] This invention can be used in the processing of thick plates, composite material plates, metal plates, ceramic substrates, glass plates, semiconductor materials, printed circuit boards, multilayer composite materials, and other materials that require segmented processing by the first and second surfaces to form through holes. It is especially suitable for high aspect ratio holes, non-circular holes, irregularly shaped holes, and double-sided drilling or double-sided scanning processing scenarios where the connection accuracy between the two segments of the hole is required to be high. Background Technology

[0003] In machining thick plates, small holes, high aspect ratio holes, irregularly shaped holes, or holes requiring high machining quality, drilling through the material from only one side in a single pass can easily lead to problems such as drill bit deflection, hole axis misalignment, exit burrs, hole wall ablation, out-of-roundness of the hole, drill breakage, excessively large heat-affected zone, or deviation in the penetration position. For processes such as mechanical drilling, laser drilling, electrical discharge machining, ultrasonic machining, milling, or scanning machining, excessive machining depth on one side can also result in insufficient tool rigidity, difficulty in chip removal, energy attenuation, or difficulty in maintaining stable control of the machining area. Therefore, in actual machining, a method of machining in sections from both sides of the material and then finally penetrating through is often adopted to reduce the machining depth on one side and improve the hole machining quality.

[0004] In existing double-sided drilling positioning solutions, one type of solution mainly relies on positioning holes, positioning pins, fixtures, positioning edges, or drill table references for front and back positioning. For example, existing technologies use multiple positioning holes on the sheet metal and positioning pins that mate with the positioning holes on the drilling fixture or drill table. Positioning is achieved by using the positioning holes and positioning pins during drilling on both the front and back sides. This type of solution is applicable to sheet metal with stable positioning holes, positioning edges, or fixture references, but the positioning accuracy is usually affected by factors such as the machining accuracy of the positioning holes, the clearance of the pin holes, the repeated clamping error of the fixture, the clamping state after flipping, and local deformation of the material. For materials without pre-set positioning holes, flexible materials, brittle materials, thick plate materials, and scenarios where reverse machining is required based on the actual position of the first section of holes, relying solely on repeated clamping with mechanical references is insufficient to fully guarantee the accurate connection of the axis of the holes on both sides.

[0005] Another type of existing solution focuses on processing parameters, hole diameter difference, positioning hole arrangement, or fixture positioning method during the drilling process on both sides. This type of solution can improve the drilling quality of thick boards or printed circuit boards to some extent, but it usually still uses mechanical references, original design coordinates, or preset processing coordinates as the basis for reverse processing, and does not directly use the actual hole entrance, hole center, or hole outline formed after the first stage of processing for visual repositioning. When the material undergoes positional deviation during flipping, clamping and release, thermal deformation, or movement, the second stage of processing may still misalign with the first stage of processing, resulting in stepped holes, eccentric holes, figure-eight holes, or holes that are not completely connected between the two stages of processing.

[0006] In terms of visual positioning, dual-camera positioning, robot vision hole position detection, or binocular vision measurement technologies already exist. These technologies can typically establish a correspondence between camera image coordinates and machine coordinates, or detect hole positions, hole axes, hole orientations, or feature point locations through visual images. However, most existing visual positioning technologies focus on camera self-calibration, the coordinate relationship between the camera and the motion mechanism, hole position detection, or workpiece orientation measurement, and do not establish a continuous repositioning relationship between "first camera device—second camera device—common optical axis—machining axis—shifting stage movement parameters" for double-sided drilling processes.

[0007] For double-sided segmented drilling, secondary positioning after material flipping is not a simple repetition of the front-side positioning. After material flipping, the corresponding position of the first segment of the hole on the second surface may deviate from the theoretical position due to flipping direction, clamping errors, table backlash, shifting stage rotation errors, thermal drift, or machining runout. If the hole to be machined is a round hole or a rotationally symmetric hole, secondary positioning can usually be completed through the hole center; however, when the hole to be machined is an oblong hole, a waist-shaped hole, an elliptical hole, a polygonal hole, a slotted hole, a notched hole, or other hole types with non-rotationally symmetric characteristics, it is also necessary to determine the in-plane rotation angle after flipping. For irregularly shaped holes or hole types with scanning path direction requirements, it is also necessary to correct the path points, scanning direction, contour sequence, start position, and end position based on the coordinate mirror relationship after flipping.

[0008] Therefore, it is necessary to provide a double-sided drilling positioning device and method based on opposing dual-camera visual repositioning, so that two camera devices located on opposite sides of the material to be processed form a common optical axis, and the relative positional relationship between the common optical axis and the processing axis is determined in advance; before processing the front side, the first camera device determines the target hole position, and after the first section is processed and flipped, the second camera device re-determines the corresponding position of the first hole section, and determines whether in-plane rotation angle correction or mirror path correction is needed according to the hole shape, so that the second section processing can accurately connect with the first section processing and form a through hole. Summary of the Invention

[0009] The purpose of this invention is to provide a double-sided drilling positioning device and method based on opposing dual-camera visual repositioning, so as to solve or improve the problems in existing double-sided drilling positioning, such as limited accuracy due to repeated clamping with mechanical reference, large secondary positioning error after flipping, difficulty in performing reverse visual repositioning based on the true position of the first hole, and difficulty in accurately correcting the direction and mirror path after flipping non-circular or irregular holes.

[0010] To achieve the above objectives, the present invention provides a double-sided drilling positioning device based on opposing dual-camera visual repositioning, including a processing device (12), a shifting stage (1), a first five-axis adjustment system (3), a first camera device (4), a second camera device (9), a second five-axis adjustment system (10), and a control system.

[0011] The processing equipment (12) has a processing axis (11) for drilling or scanning the material (6) to be processed. The processing axis (11) can be the drill axis, the laser beam center axis, the ultrasonic machining tool axis, the electrical discharge machining electrode axis, the milling tool axis, the machining head center axis, or the reference axis of the scanning machining coordinate system.

[0012] The shifting stage (1) is used to carry and move the material to be processed (6). The shifting stage (1) has translational degrees of freedom in the X and Y directions in a unified spatial coordinate system, as well as rotational degrees of freedom about the X and Y axes. The unified spatial coordinate system refers to the equipment coordinate system used to describe the relative positional relationships between the first camera device (4), the second camera device (9), the shifting stage (1), the material to be processed (6), and the processing equipment (12). Depending on the processing object and hole shape requirements, the shifting stage (1) may also have rotational degrees of freedom about the Z axis for in-plane angle correction.

[0013] The first camera device (4) is installed on the first five-axis adjustment system (3). The second camera device (9) is installed on the second five-axis adjustment system (10). The first camera device (4) and the second camera device (9) are respectively set on opposite sides of the material to be processed (6). The first five-axis adjustment system (3) and the second five-axis adjustment system (10) both use a unified spatial coordinate system as the adjustment reference and both have translational adjustment degrees of freedom along the X, Y and Z directions, as well as angular adjustment degrees of freedom around at least two intersecting axes. The angular adjustment degrees of freedom include at least pitch angle adjustment degrees of freedom and yaw angle adjustment degrees of freedom, so that the optical axis of the first camera device (4) and the optical axis of the second camera device (9) are coaxially aligned and form a common optical axis (2). The common optical axis refers to the same reference optical axis or a visual positioning axis that is approximately coaxial for dual-sided visual positioning after the first camera device (4) and the second camera device (9) are coaxially calibrated.

[0014] The control system is connected to the processing equipment (12), the shifting stage (1), the first camera (4), and the second camera (9), respectively. The control system is used to control the shifting stage (1) and the processing equipment (12) to complete the double-sided drilling and positioning processing of the material to be processed (6) based on the relative positional relationship between the common optical axis (2) and the processing axis (11), the image recognition results before and after the flipping of the material to be processed (6), and the movement parameters of the shifting stage (1).

[0015] The control system is configured to: determine the position of the target hole (8) of the material to be processed (6) before it is turned over relative to the common optical axis (2) by the first camera device (4); determine the position of the first hole segment of the material to be processed (6) after it is turned over relative to the common optical axis (2) by the second camera device (9); and determine the in-plane rotation angle and / or the correction parameters of the second processing path of the material to be processed (6) after it is turned over according to the hole shape of the hole.

[0016] The first camera device (4) and the second camera device (9) can be any one of a CCD camera, a CMOS camera, an industrial camera, a microscope camera, or a line scan camera. The resolution of the first camera device (4) and the second camera device (9) can be from 300,000 pixels to 50 million pixels, the focal length of the lens can be from 1 mm to 200 mm, the working distance can be from 1 mm to 1000 mm, the depth of field can be from 0.01 mm to 200 mm, the field of view can be from 1° to 180°, the field of view range can be from 0.1 mm × 0.1 mm to 1000 mm × 1000 mm, and the numerical aperture can be from 0.01 to 0.95. Preferably, both the first camera device (4) and the second camera device (9) are industrial area scan cameras with a resolution of 5 million pixels to 20 million pixels, a focal length of 10 mm to 100 mm, a working distance of 20 mm to 300 mm, and a field of view range of 5 mm × 5 mm to 200 mm × 200 mm.

[0017] The translation adjustment range of the first five-axis adjustment system (3) and the second five-axis adjustment system (10) in the X, Y, and Z directions can be ±0.01 mm to ±500 mm, respectively, and the rotation adjustment range around the pitch and yaw directions can be ±0.01° to ±90°, respectively. The movement range of the shift stage (1) in the X and Y directions can be 0.1 mm to 3000 mm, respectively, and the rotation range around the X and Y axes can be ±0.01° to ±90°, respectively. The processing equipment (12) can be any one of mechanical drilling equipment, laser drilling equipment, ultrasonic drilling equipment, electrical discharge machining equipment, milling equipment, or scanning processing equipment.

[0018] The present invention also provides a double-sided drilling positioning method based on opposing dual-camera visual repositioning, comprising providing a processing device (12), a shifting stage (1), a first camera device (4), and a second camera device (9). The first camera device (4) and the second camera device (9) are respectively disposed on opposite sides of the material to be processed (6), and the processing device (12) has a processing axis (11). The method includes the following steps.

[0019] S1, before processing the material (6), the first camera (4) and the second camera (9) are coaxially aligned so that the optical axis of the first camera (4) and the optical axis of the second camera (9) form a common optical axis (2).

[0020] S2, determine the relative positional relationship between the common optical axis (2) and the machining axis (11). The relative positional relationship is obtained by measuring through pre-drilled holes, standard holes, calibration targets, standard calibration plates, or trial machining holes.

[0021] S3, the material to be processed (6) is placed on the shift stage (1), and the target hole (8) to be processed on the material to be processed (6) is moved to the visual positioning position corresponding to the common optical axis (2); the first camera device (4) collects the image of the target hole (8), and the position of the target hole (8) relative to the common optical axis (2) is determined according to the collected image.

[0022] S4, based on the relative positional relationship between the common optical axis (2) and the machining axis (11), control the shifting stage (1) to move the target hole (8) from the visual positioning position to the machining position corresponding to the machining axis (11); control the machining equipment (12) to perform the first segment machining on the target hole (8) from the first surface (5) of the material to be processed (6) to form the first hole segment.

[0023] S5, after the first hole segment is formed, the material to be processed (6) is flipped over by a shift table (1) or other flipping method, so that the second surface (7) of the material to be processed (6) faces the processing equipment (12), and the position of the first hole segment after flipping is moved to the visual positioning position corresponding to the common optical axis (2).

[0024] S6, the image of the corresponding position of the first hole segment after flipping is acquired by the second camera device (9), the position of the corresponding position of the first hole segment after flipping relative to the common optical axis (2) is determined according to the acquired image, and it is determined whether the relative angle of the material to be processed (6) after flipping meets the preset processing requirements; when the hole to be processed is a round hole or a rotationally symmetric hole, secondary positioning is performed according to the hole center position determined by the second camera device (9); when the hole to be processed is a hole with non-rotationally symmetric features, the in-plane rotation angle of the material to be processed (6) after flipping is determined according to the edge contour, main contour direction, long axis direction, short axis direction, feature corner point, feature edge, preset mark point or the line direction between at least two feature points, and the rotation alignment of the material to be processed (6) is performed according to the in-plane rotation angle, or the processing path direction of the second segment is corrected; when the hole to be processed is an irregular hole, the mirror change of the irregular hole position is determined according to the coordinate mirror relationship after the material to be processed (6) is flipped, and the processing path of the second segment is mirror corrected.

[0025] S7. After completing the secondary positioning through the second camera device (9), according to the relative positional relationship between the common optical axis (2) and the processing axis (11), the shifting stage (1) is controlled to move the corresponding position of the first hole segment after flipping from the visual positioning position to the processing position.

[0026] S8, control the processing equipment (12) to perform a second segment processing on the target hole (8) from the second surface (7) to form a second hole segment, and make the second hole segment connect with the first hole segment to form a through hole.

[0027] In step S6, the circular hole positioning, non-rotationally symmetric hole angle correction, and irregular hole mirror path correction can be performed one of them according to the hole shape of the hole to be processed, or they can be performed in combination when the same hole to be processed has the requirements for position, angle and mirror correction.

[0028] In step S1, the coaxial alignment of the first camera device (4) and the second camera device (9) may include: 1A, setting a calibration element between the first camera device (4) and the second camera device (9), wherein the calibration element is a transparent calibration element with a marking pattern, a glass calibration element with a marking pattern, or a through-hole calibration element with a calibration through-hole; 1B, acquiring images of the same marking pattern or the same calibration through-hole through the first camera device (4) and the second camera device (9) respectively, and identifying the imaging center of the same marking pattern or the same calibration through-hole; 1C, adjusting the position, focus, pitch angle, and yaw angle of the first camera device (4) and / or the second camera device (9) so that the imaging center of the first camera device (4) and the second camera device (9) coincides, or making the deviation between them less than a preset dual-camera calibration threshold. The preset dual-camera calibration threshold is 0.1 μm to 500 μm.

[0029] In step S2, determining the relative positional relationship between the common optical axis (2) and the machining axis (11) may include: 2A, moving the calibration material to the machining position corresponding to the machining axis (11) and forming a pre-drilled hole using the machining equipment (12); 2B, moving the pre-drilled hole to the visual positioning position corresponding to the common optical axis (2); acquiring an image of the pre-drilled hole using the first camera device (4) or the second camera device (9) and determining the identification center of the pre-drilled hole; 2C, determining the coordinate offset between the common optical axis (2) and the machining axis (11) in the X direction and / or Y direction based on the displacement of the calibration material when it moves from the machining position to the visual positioning position. The coordinate offset may be from 0.01 mm to 3000 mm.

[0030] The diameter, equivalent diameter, circumscribed circle diameter, or maximum profile dimension of the hole to be processed can be from 0.01 mm to 300 mm. The length of the material to be processed (6) can be from 1 mm to 3000 mm, the width can be from 1 mm to 3000 mm, and the thickness can be from 0.01 mm to 500 mm.

[0031] When determining the position of the target hole (8) relative to the common optical axis (2) using the first camera device (4), and / or determining the position of the corresponding position of the first hole segment after flipping relative to the common optical axis (2) using the second camera device (9), the center, edge contour, gray center, geometric center, feature corner point, feature edge, main contour direction, major axis direction, minor axis direction, preset marker point, or the direction of the line connecting at least two feature points of the target hole (8) or the corresponding position of the first hole segment can be extracted, and the deviation between it and the image center corresponding to the common optical axis (2) can be determined based on the extraction result. This deviation is less than a preset visual positioning threshold, which can be from 0.1 μm to 1000 μm.

[0032] The machining depth of the first stage is less than the equivalent thickness of the material to be processed (6) in the direction of the target hole axis, so that the first hole segment does not penetrate the material to be processed (6). The machining depth of the first stage can be 1% to 99% of the equivalent thickness. The machining depth of the second stage is the depth that enables the second hole segment to connect with the first hole segment and form a through hole. The overlap length of the first hole segment and the second hole segment in the direction of the target hole axis can be 0.001 mm to 100 mm.

[0033] Before moving the position corresponding to the first hole segment after flipping from the visual positioning position to the processing position, the control system can also correct the movement parameters of the shifting stage (1) and / or the processing path of the second segment processing according to at least one of the following: the flipping direction of the material to be processed (6), the relative positional relationship between the common optical axis (2) and the processing axis (11), the back clearance of the shifting stage (1), the rotation angle error of the shifting stage, the thermal drift, the camera calibration error, the axis runout error of the processing equipment, and the clamping error of the material to be processed. When the processing path of the second segment processing is mirrored, the mirror axis or mirror plane is determined according to the flipping direction of the material to be processed (6), and at least one of the path points, scanning directions, contour sequences, starting positions and ending positions in the first segment processing path is transformed according to the mirror axis or mirror plane. The processing equipment (12) is controlled to perform the second segment processing according to the processing path after the coordinate transformation.

[0034] Since the first camera (4) and the second camera (9) form a common optical axis (2), the material to be processed (6) can be positioned with the same visual positioning reference both before and after flipping, thereby reducing the error introduced by the coordinate transformation of the front and back images. Since the relative positional relationship between the common optical axis (2) and the processing axis (11) can be pre-calibrated and repeatedly called, a corresponding movement relationship can be established between the visual positioning position and the actual processing position. Since the actual corresponding position of the first hole segment is re-identified by the second camera (9) before the second segment of processing, the errors of flipping, clamping and releasing, material deformation and shifting table movement can be compensated. For hole types and irregular holes with non-rotational symmetry characteristics, the consistency of the processing paths of the front and back segments can be improved by judging the in-plane angle and correcting the mirror path. Attached Figure Description

[0035] Figure 1 The diagram shows the structure of a dual-sided drilling positioning device based on opposing dual-camera visual repositioning, illustrating the relative arrangement of the shifting stage (1), common optical axis (2), first five-axis adjustment system (3), first camera device (4), first surface (5), material to be processed (6), second surface (7), target hole position (8), second camera device (9), second five-axis adjustment system (10), processing axis (11), and processing equipment (12).

[0036] Figure 2 The diagram shows the relative positional relationship between the common optical axis and the machining axis, as well as the machining status of the first section on the front. It shows the corresponding relationship between the common optical axis (2), the first five-axis adjustment system (3), the first camera device (4), the material to be processed (6), the second camera device (9), the second five-axis adjustment system (10), the machining axis (11), the machining equipment (12), and the corresponding position (13) of the hole entrance or the first hole section.

[0037] Figure 3 This is a schematic diagram showing the offset and mirror relationship of the hole inlet positions before and after the turning process of the material (6). It shows the corresponding positions (13) of the hole inlet or the first hole segment before and after the turning process of the material (6), the offset in the first direction (14) and the offset in the second direction (15).

[0038] Figure 4 The diagram illustrates the secondary positioning, movement to the processing position and the second segment processing, showing the common optical axis (2), the material to be processed (6), the second camera device (9), the processing axis (11), the hole entrance or the corresponding position of the first hole segment (13), the second hole segment or the through area (16), and the direction of movement (17).

[0039] Figure 5 This is a flowchart illustrating a dual-sided drilling positioning method based on opposing dual-camera visual repositioning. It shows the sequence of steps: S1 Coaxial alignment of the dual-camera devices, S2 Determination of the relative position of the common optical axis and the machining axis, S3 Positioning of the target hole by the first camera device, S4 Moving to the machining axis and performing the first stage of machining, S5 Flipping the material, S6 Identification and secondary positioning by the second camera device, S7 Reverse movement to the machining axis, and S8 Connecting the second stage of machining.

[0040] Explanation of reference numerals in the attached drawings: 1. Shifting stage; 2. Common optical axis; 3. First five-axis adjustment system; 4. First camera device; 5. First surface; 6. Material to be processed; 7. Second surface; 8. Target hole position; 9. Second camera device; 10. Second five-axis adjustment system; 11. Processing axis; 12. Processing equipment; 13. Hole entrance or corresponding position of the first hole segment; 14. First direction offset; 15. Second direction offset; 16. Second hole segment or through area; 17. Direction of movement. Detailed Implementation

[0041] The present invention will be further described below with reference to embodiments. These embodiments are used to illustrate the implementation of the present invention and are not intended to limit the scope of protection of the present invention. Where there is no contradiction, the technical features of the various embodiments can be combined with each other.

[0042] In this invention, "first surface (5)" refers to the surface of the material to be processed (6) facing the processing equipment (12) during the first stage of processing; "second surface (7)" refers to the surface of the material to be processed (6) facing the processing equipment (12) after it has been flipped over. "First stage processing" refers to the processing process of forming the first hole segment from the side of the first surface (5); "second stage processing" refers to the processing process of forming the second hole segment from the side of the second surface (7) and communicating with the first hole segment. "Corresponding position of the first hole segment" refers to the first hole segment entrance, hole segment projection center, hole segment edge contour, or visual feature position corresponding to the first hole segment that can be identified by the second camera device (9) after the first stage of processing and when the material is flipped over.

[0043] Example 1: A complete embodiment of the device structure.

[0044] This embodiment provides a double-sided drilling positioning device based on opposing dual-camera visual repositioning. The device includes a processing equipment (12), a shifting stage (1), a first five-axis adjustment system (3), a first camera device (4), a second camera device (9), a second five-axis adjustment system (10), and a control system.

[0045] The processing equipment (12) is located on one side of the shifting stage (1) and is used to drill or scan the material (6) to be processed. The processing equipment (12) has a processing axis (11). When the processing equipment (12) is a mechanical drilling equipment, the processing axis (11) is the center axis of the drill bit; when the processing equipment (12) is a laser drilling equipment, the processing axis (11) is the center axis of the laser beam or the optical axis of the processing head; when the processing equipment (12) is an ultrasonic drilling equipment, the processing axis (11) is the center axis of the ultrasonic tool; when the processing equipment (12) is an electrical discharge machining equipment, the processing axis (11) is the center axis of the electrode; when the processing equipment (12) is a scanning processing equipment, the processing axis (11) is the processing reference axis of the scanning coordinate system.

[0046] A shift stage (1) is used to carry the material to be processed (6) and move the material to be processed (6) between the visual positioning position corresponding to the common optical axis (2) and the processing position corresponding to the processing axis (11). The shift stage (1) has translational degrees of freedom in the X and Y directions, and rotational degrees of freedom about the X and Y axes. The movement range of the shift stage (1) in the X and Y directions can be 0.1 mm to 3000 mm, and the rotation range about the X and Y axes can be ±0.01° to ±90°, respectively. In embodiments where in-plane angle correction is required for non-circular holes or irregular holes, the shift stage (1) may also include a rotary table that rotates about the Z axis, with a rotation range about the Z axis of ±0.01° to ±180°.

[0047] The first five-axis adjustment system (3) is used to install and adjust the first camera device (4). The second five-axis adjustment system (10) is used to install and adjust the second camera device (9). Both the first five-axis adjustment system (3) and the second five-axis adjustment system (10) include an X-axis fine-tuning mechanism, a Y-axis fine-tuning mechanism, a Z-axis focusing mechanism, a pitch angle adjustment mechanism, and a yaw angle adjustment mechanism. The translation adjustment ranges of the first five-axis adjustment system (3) and the second five-axis adjustment system (10) in the X, Y, and Z directions are ±0.01 mm to ±500 mm, respectively, and the rotation adjustment ranges around the pitch and yaw directions are ±0.01° to ±90°, respectively. In a preferred embodiment, the translation adjustment resolution is 0.001 mm to 0.01 mm, and the angle adjustment resolution is 0.001° to 0.01°.

[0048] The first camera (4) and the second camera (9) are respectively arranged on opposite sides of the material to be processed (6). The first camera (4) is used to acquire images of the target hole (8) on the side of the first surface (5) before the material to be processed (6) is turned over. The second camera (9) is used to acquire images of the corresponding positions of the first hole segments on the side of the second surface (7) after the material to be processed (6) is turned over. The first camera (4) and the second camera (9) can be any of a CCD camera, a CMOS camera, an industrial camera, a microscope camera, or a line scan camera. The resolution of the first camera (4) and the second camera (9) is 300,000 to 50,000,000 pixels, the focal length of the lens is 1 mm to 200 mm, the working distance is 1 mm to 1000 mm, the depth of field is 0.01 mm to 200 mm, the field of view is 1° to 180°, the field of view range is 0.1 mm × 0.1 mm to 1000 mm × 1000 mm, and the numerical aperture is 0.01 to 0.95. As a specific example, both the first camera device (4) and the second camera device (9) use a 12-megapixel industrial camera with a lens focal length of 50 mm, a working distance of 120 mm, a field of view of 20 mm × 20 mm, and a numerical aperture of 0.10.

[0049] The control system may include one or more of the following: an industrial computer, a motion controller, an image acquisition card, a programmable controller, a servo driver, an image processing module, and a machining control module. The control system is connected to the machining equipment (12), the shift stage (1), the first camera device (4), and the second camera device (9), respectively. The image processing module is used to extract the center, edge contour, grayscale center, geometric center, feature corner points, feature edges, main contour direction, major axis direction, minor axis direction, preset marker points, or the direction of the line connecting at least two feature points at the corresponding position of the target hole (8) or the first hole segment. The motion controller is used to generate the movement parameters of the shift stage (1) based on the visual recognition results and the relative positional relationship between the common optical axis (2) and the machining axis (11). The machining control module is used to control the machining equipment (12) to perform the first and second stages of machining.

[0050] The length of the material to be processed (6) can be from 1 mm to 3000 mm, the width can be from 1 mm to 3000 mm, and the thickness can be from 0.01 mm to 500 mm. The diameter, equivalent diameter, circumscribed circle diameter, or maximum profile dimension of the hole to be processed can be from 0.01 mm to 300 mm. As a specific example, the material to be processed (6) is a carbon fiber composite plate with a thickness of 20 mm, the hole to be processed is a through hole with an equivalent diameter of 2 mm, the processing depth of the first segment is 9.8 mm, the processing depth of the second segment is 10.5 mm, and the overlap length between the first and second hole segments is 0.3 mm.

[0051] Example 2: Implementation method of coaxial alignment of dual camera devices.

[0052] Before processing the material (6), step S1 is performed to perform coaxial alignment of the first camera device (4) and the second camera device (9). The purpose of coaxial alignment is to make the optical axis of the first camera device (4) and the optical axis of the second camera device (9) form a common optical axis (2), so that the visual positioning of the material before and after turning over is based on the same visual reference.

[0053] During coaxial alignment, a calibration element is placed between the first camera device (4) and the second camera device (9) according to step 1A. The calibration element can be a transparent calibration element with crosshairs, dots, checkerboard patterns, concentric circles, or QR code markings, or a glass calibration element with marking patterns, or a through-hole calibration element with calibration through holes. The diameter of the calibration through holes can be from 0.01 mm to 10 mm, preferably from 0.05 mm to 1 mm.

[0054] According to step 1B, the first camera device (4) acquires an image of the first side of the calibration component, and the second camera device (9) acquires an image of the second side of the calibration component. The control system identifies the imaging center of the same marking pattern or the same calibration through hole in the two images respectively. The imaging center can be obtained by gray-scale centroid method, edge fitting method, circle fitting method, Hough circle detection method, template matching method or subpixel contour fitting method.

[0055] According to step 1C, if there is a deviation between the imaging center acquired by the first camera device (4) and the imaging center acquired by the second camera device (9), the X-axis position, Y-axis position, Z-axis focal point position, pitch angle, and yaw angle of the corresponding camera device are adjusted by the first five-axis adjustment system (3) and / or the second five-axis adjustment system (10). The adjustment process can be carried out in the order of translation, then angle adjustment, then focus adjustment, and then verification. First, adjust the X-axis position and Y-axis position to reduce the center deviation of the mark center identified by the two camera devices in their respective image coordinates; second, adjust the pitch angle and yaw angle to reduce the center drift of the mark pattern at different focal plane positions; third, adjust the Z-axis focal point position to make the mark edge clarity meet the recognition requirements; fourth, repeatedly acquire images and calculate the dual-camera center deviation.

[0056] Coaxial alignment is achieved when the imaging centers of the first camera device (4) and the second camera device (9) coincide for the same marking pattern or the same calibration through-hole, or when the deviation between them is less than the preset dual-camera calibration threshold. The preset dual-camera calibration threshold ranges from 0.1 μm to 500 μm. As a specific example, in a processing scenario with a hole diameter of 2 mm and a material thickness of 20 mm, the preset dual-camera calibration threshold is set to 10 μm; in a micro-hole processing scenario, the preset dual-camera calibration threshold can be set from 1 μm to 5 μm.

[0057] After coaxial alignment is completed, the control system records the calibration parameters of the first camera device (4) and the second camera device (9), including pixel size, camera intrinsic parameters, distortion parameters, image center position, the proportional relationship between pixel coordinates and the unified spatial coordinate system, and the visual center coordinates corresponding to the common optical axis (2). These calibration parameters are used for subsequent visual recognition and coordinate conversion of the target hole position (8) and the corresponding position of the first hole segment.

[0058] Example 3: Implementation method for determining the relative position of the common optical axis and the machining axis.

[0059] Since the common optical axis (2) corresponds to the visual positioning position, while the machining axis (11) corresponds to the actual machining position, step S2 is executed to predetermine the relative positional relationship between the common optical axis (2) and the machining axis (11). This relative positional relationship can be represented by coordinate offsets in a unified spatial coordinate system, or by a coordinate transformation matrix that includes translation and rotation relationships.

[0060] In one embodiment, the relative positional relationship between the common optical axis (2) and the machining axis (11) is determined by pre-drilling. The specific steps are as follows.

[0061] 2A, fix the calibration material on the shift stage (1) and control the shift stage (1) to move the calibration material to the machining position corresponding to the machining axis (11); control the machining equipment (12) to form a pre-drilled hole on the calibration material. The pre-drilled hole can be a round hole, a shallow hole, a blind hole or a marking hole, and its diameter can be from 0.01 mm to 10 mm.

[0062] 2B, control the shift stage (1) to move the pre-drilled hole to the visual positioning position corresponding to the common optical axis (2); acquire the pre-drilled hole image through the first camera device (4) or the second camera device (9), and determine the identification center of the pre-drilled hole.

[0063] 2C. Based on the displacement of the shift stage (1) when the calibration material moves from the processing position to the visual positioning position, determine the coordinate offset between the common optical axis (2) and the processing axis (11) in the X and / or Y directions. The coordinate offset can be from 0.01 mm to 3000 mm. As a specific example, the X-direction coordinate offset is 86.520 mm and the Y-direction coordinate offset is 12.340 mm.

[0064] In another implementation, the relative positional relationship between the common optical axis (2) and the machining axis (11) is determined by standard holes, calibration targets, or standard calibration plates. The standard calibration plate has multiple standard holes or markers. The control system acquires the coordinates of the standard holes or markers at the visual positioning position and the machining position, respectively, and obtains the coordinate offset between the common optical axis (2) and the machining axis (11) by combining the readings from the shift stage (1). This method is suitable for machining scenarios where pre-drilling is inconvenient or requires periodic rapid calibration.

[0065] In another embodiment, the relative positional relationship between the common optical axis (2) and the machining axis (11) is obtained by measuring through a trial machining hole. The trial machining hole can be formed on the sample by a machining device (12). After the first camera device (4) or the second camera device (9) identifies the center position of the trial machining hole, the control system corrects the coordinate offset between the common optical axis (2) and the machining axis (11) based on the deviation between the actual center and the target center of the trial machining hole.

[0066] Figure 3 The corresponding first-direction offset (14) and second-direction offset (15) can be used to represent the positional difference of the front and rear hole entrances or the corresponding positions (13) of the first hole segment in a unified spatial coordinate system. The first-direction offset (14) can correspond to the Y-direction offset, and the second-direction offset (15) can correspond to the X-direction offset. The control system can use the first-direction offset (14) and second-direction offset (15) as the data source for secondary positioning and error compensation.

[0067] Example 4: Implementation method of front positioning and first stage processing.

[0068] Frontal positioning and the first stage of processing are performed with the first surface (5) of the material to be processed (6) facing the processing equipment (12). The control system first executes step S3, controlling the shift stage (1) to move the target hole (8) to the visual positioning position corresponding to the common optical axis (2). The target hole (8) can be a preset design coordinate, material surface mark, existing shallow hole, positioning pattern, contour feature, or a position determined by CAD / CAM processing path.

[0069] The first camera device (4) acquires an image of the target hole (8). The control system preprocesses the acquired image, which may include grayscale conversion, filtering, brightness compensation, distortion correction, edge enhancement, and threshold segmentation. Subsequently, the control system extracts the corresponding positioning features according to the type of the target hole (8). When the target hole (8) is a circular mark, the center of the circle is extracted; when the target hole (8) is a cross mark, the intersection of the two lines is extracted; when the target hole (8) is a non-circular contour, the geometric center, grayscale center, or contour main direction is extracted; when the target hole (8) has multiple feature points, the direction of the line connecting at least two feature points is extracted.

[0070] The control system calculates the deviation between the target aperture (8) and the image center corresponding to the common optical axis (2). If the image coordinate deviation is (du, dv) and the pixel equivalent is k, then the spatial coordinate deviation can be expressed as (dx, dy) = (k·du, k·dv). The control system controls the shift stage (1) to make fine adjustments based on (dx, dy) so that the deviation between the target aperture (8) and the image center corresponding to the common optical axis (2) is less than the preset visual positioning threshold. The preset visual positioning threshold is from 0.1 μm to 1000 μm. As a specific example, the preset visual positioning threshold is set to 5 μm.

[0071] After visual positioning of the target hole (8) is completed, step S4 is executed. The control system generates the movement parameters of the shift stage (1) from the visual positioning position to the machining position based on the relative positional relationship between the common optical axis (2) and the machining axis (11). If the coordinate offset between the common optical axis (2) and the machining axis (11) is (ΔX, ΔY), and the remaining positioning deviation of the target hole (8) relative to the common optical axis (2) is (ex, ey), then the movement parameters of the shift stage (1) can be (MX, MY) = (ΔX−ex, ΔY−ey). When the control system uses the opposite coordinate definition, the above signs can be uniformly adjusted according to the coordinate direction.

[0072] After the shifting stage (1) completes its movement, the target hole (8) is positioned at the machining position corresponding to the machining axis (11). The control system controls the machining equipment (12) to perform a first-stage machining from the first surface (5) to form a first hole segment. The first-stage machining can be performed by mechanical drilling, laser drilling, ultrasonic drilling, electrical discharge machining, milling, or scanning machining. The machining depth of the first stage is 1% to 99% of the equivalent thickness of the material to be machined (6) in the direction of the target hole axis. Preferably, the machining depth of the first stage is 40% to 60% of the equivalent thickness. As a specific example, when the thickness of the material to be machined (6) is 20 mm, the machining depth of the first stage is 9.8 mm.

[0073] After the first stage of processing is completed, the first hole segment does not penetrate the material to be processed (6) or is only close to penetrating. This state is beneficial for identifying the corresponding position of the first hole segment from the second surface (7) side after flipping, and for making the second stage of processing connected with the first stage of processing inside the material.

[0074] Example 5: Implementation method of secondary visual positioning and second-stage processing after flipping.

[0075] After the first stage of processing is completed, step S5 is executed to flip the material (6) to be processed so that the second surface (7) faces the processing equipment (12). Flipping can be accomplished by the flipping mechanism of the shift table (1), or by an external robot, flipping platform, fixture flipping mechanism, or manual clamping. The flipping direction can be around the X-axis, around the Y-axis, around any fixture axis, or after rotating in the material plane.

[0076] After flipping, the control system controls the shifting stage (1) to move the position corresponding to the first hole segment to the visual positioning position corresponding to the common optical axis (2). Step S6 is executed, and the second camera device (9) acquires the image of the position corresponding to the first hole segment. Since the second camera device (9) and the first camera device (4) are already coaxially aligned and form a common optical axis (2), the second camera device (9) can identify the actual corresponding position of the first hole segment after flipping based on the same visual positioning reference.

[0077] The control system performs edge detection, contour extraction, circle fitting, grayscale center calculation, template matching, or feature point recognition on the image acquired by the second camera device (9) to determine the deviation of the corresponding position of the first hole segment relative to the common optical axis (2). For circular holes or rotationally symmetric holes, the control system extracts the hole center as a secondary positioning reference. For non-circular holes or irregularly shaped holes, the control system simultaneously extracts the main contour direction, major axis direction, minor axis direction, feature corner points, feature edges, or preset marker points to determine the angular relationship after flipping.

[0078] After completing the secondary positioning, step S7 is executed. The control system generates movement parameters from the visual positioning position to the processing position based on the relative positional relationship between the common optical axis (2) and the processing axis (11), the positional deviation identified by the second camera device (9), and the error compensation parameters. The movement direction (17) can be the direction from the corresponding position of the common optical axis (2) to the corresponding position of the processing axis (11), or it can be represented as the corresponding X-axis and Y-axis movement directions according to the coordinate definition of the shift stage (1).

[0079] After the shifting stage (1) moves the position corresponding to the first hole segment after flipping to the processing position corresponding to the processing axis (11), step S8 is executed. The control system controls the processing equipment (12) to perform a second segment processing from the second surface (7) to form a second hole segment or a through area (16). The processing depth of the second segment is set to a depth that allows the second hole segment to connect with the first hole segment and form a through hole. The connection overlap length of the first hole segment and the second hole segment in the direction of the target hole axis is 0.001 mm to 100 mm. As a specific example, when the thickness of the material to be processed (6) is 20 mm and the processing depth of the first segment is 9.8 mm, the processing depth of the second segment is 10.5 mm and the connection overlap length is 0.3 mm.

[0080] Example 6: Implementation of angle judgment and path correction for different hole types.

[0081] When the hole to be processed is a round hole or a rotationally symmetric hole, the geometric contour of the hole remains unchanged after rotation in the plane. The control system can identify the center position of the hole through the second camera device (9) and use the hole center as a secondary positioning reference. In this case, it is usually not necessary to correct the in-plane rotation angle of the material to be processed (6) or to correct the direction of the second processing path.

[0082] When the hole to be processed is a non-rotationally symmetric hole, such as an oblong hole, waist-shaped hole, elliptical hole, polygonal hole, slotted hole, notched hole, or hole with a directional profile, the control system needs to determine not only the hole center position but also the in-plane rotation angle after flipping. The in-plane rotation angle can be obtained through at least one of the following methods.

[0083] The first method determines the in-plane rotation angle based on the principal direction of the contour. The control system extracts the hole contour point set and calculates the principal direction of the contour through principal component analysis. The design principal direction of the target hole position (8) before flipping is denoted as α0, and the principal direction of the contour obtained by the second camera device (9) after flipping is denoted as α1. The in-plane rotation angle can be expressed as θ = α1 − α0. The control system controls the shifting stage (1) to rotate around the Z-axis for alignment according to θ, or rotates the second processing path as a whole by −θ.

[0084] The second method determines the in-plane rotation angle based on either the major or minor axis direction. For elliptical, oblong, or waist-shaped holes, the control system fits the hole profile and obtains the major and minor axis directions. The angle between the major axis direction after flipping and the designed major axis direction is used as the in-plane rotation angle. If the hole shape has a 180° directional equivalence, the control system can normalize the angle to the range of 0° to 180°.

[0085] The third method determines the in-plane rotation angle based on feature corner points, feature edges, or preset marker points. For polygonal holes, holes with notches, or holes with directional markers, the control system identifies at least one feature corner point or feature edge; for holes with multiple feature points, the control system identifies the direction of the line connecting at least two feature points. The angle between the direction of the line after flipping and the designed direction of the line is used to determine the in-plane rotation angle.

[0086] When the hole to be processed is an irregularly shaped hole, flipping will cause a mirror relationship between the path coordinates observed on the second surface (7) and the designed path on the first surface (5). The control system determines the mirror axis or mirror plane according to the flipping direction of the material to be processed (6). If the material to be processed (6) is flipped around the X-axis, the Y-direction can be used as the mirror reverse direction; if the material to be processed (6) is flipped around the Y-axis, the X-direction can be used as the mirror reverse direction; if the material to be processed (6) undergoes compound flipping and rotation, the path transformation relationship can be determined by the corresponding rotation matrix and mirror matrix.

[0087] Taking a two-dimensional planar path point P = (x, y) as an example, when flipping around the X-axis, the mirror transformation can be expressed as P′ = (x, −y); when flipping around the Y-axis, the mirror transformation can be expressed as P′ = (−x, y); when further compensation is needed for the in-plane rotation angle θ and translation amount T = (tx, ty), the second processing path point can be expressed as: P2 = R(θ)·S·P1 + T. Where P1 is the first processing path point, P2 is the second processing path point, S is the mirror matrix determined by the flipping direction, R(θ) is the in-plane rotation matrix, and T is the translation compensation amount determined by secondary visual positioning.

[0088] Mirror path correction may include correcting at least one of the following: path points, scanning direction, contour sequence, start position, and end position. For closed contour paths, the clockwise direction of the contour after mirroring may become the counterclockwise direction, and the control system can adjust the contour sequence according to the path execution requirements of the processing equipment (12). For scanning paths with entry and exit point requirements, the control system can redetermine the start and end positions after mirroring. For layered scanning paths, the control system can perform mirror transformation, rotation correction, and translation compensation for each layer of the path separately.

[0089] Example 7: Implementation of error compensation.

[0090] Before moving the position corresponding to the first hole segment after flipping from the visual positioning position to the processing position, the control system can perform error compensation on the movement parameters of the shift stage (1) and / or the processing path of the second segment. Error compensation can consider at least one of the following: the flipping direction of the material to be processed (6), the relative positional relationship between the common optical axis (2) and the processing axis (11), the back clearance of the shift stage (1), the rotation angle error of the shift stage, the thermal drift, the camera equipment calibration error, the axis runout error of the processing equipment, and the clamping error of the material to be processed.

[0091] Backlash compensation can be obtained by pre-calibrating the forward and reverse movement errors of the shift stage (1) in the X and Y directions. If the shift stage (1) moves in the opposite direction from the visual positioning position to the machining position, the control system compensates for the movement amount according to the backlash values ​​Bx and By of the corresponding axis. The movement parameters can be expressed as: MX = ΔX − ex + Cx; MY = ΔY − ey + Cy. Wherein, MX and MY are the compensated movement amounts, ΔX and ΔY are the coordinate offsets between the common optical axis (2) and the machining axis (11), ex and ey are the visual recognition deviations, and Cx and Cy are the comprehensive compensation amounts. The comprehensive compensation amounts can include backlash compensation, thermal drift compensation, calibration error compensation, and clamping error compensation.

[0092] Thermal drift compensation can be obtained through temperature sensors, periodic calibration, or online calibration. The control system records the temperature change ΔT of the equipment and calculates the thermal drift compensation amount (kx·ΔT, ky·ΔT) based on the pre-calibrated thermal drift coefficients kx and ky. In scenarios with long processing time, large laser processing heat input, or large ambient temperature fluctuations, the control system can re-acquire calibration hole images after processing a preset number of holes to update the relative positional relationship between the common optical axis (2) and the processing axis (11).

[0093] Rotation angle error compensation can be obtained through the in-plane rotation angle identified by the second camera device (9). If the material to be processed (6) has a rotation angle θe relative to the design direction after being flipped, the control system can perform solid alignment by rotating the shift stage (1) around the Z-axis by −θe, or it can introduce a rotation matrix R (−θe) in the second processing path for path correction. For the shift stage (1) which only has rotational degrees of freedom around the X-axis and Y-axis, the control system can preferentially adopt the path direction correction method.

[0094] The error compensation for the axis runout of the processing equipment can be obtained by trial machining of holes, standard holes, or hole-axis measurement. If the machining axis (11) has a small angle runout relative to the common optical axis (2), the second segment of the machining path or machining position can be laterally compensated according to the material thickness and the runout angle. If the runout angle of the machining axis (11) in the X direction is βx and the runout angle in the Y direction is βy, and the equivalent machining depth of the material to be processed (6) is h, then the lateral compensation amount can be approximately expressed as (h·tanβx, h·tanβy).

[0095] Compensation for clamping errors of the material to be processed can be obtained by identifying the material edge, fixture reference point, positioning mark, or the relative position between multiple holes. When the material to be processed (6) undergoes overall translation, rotation, or local deformation after being flipped, the control system can establish an affine transformation or local correction model through multiple visual feature points. For rigid materials, overall translation and rotation compensation can be used; for flexible materials or locally deformable materials, secondary visual positioning can be performed on different holes, and movement parameters can be generated separately.

[0096] Example 8: Complete Process Example.

[0097] A complete double-sided drilling and positioning process includes the following steps.

[0098] S1, install the first camera device (4) and the second camera device (9), and adjust their positions, focus, pitch angle and yaw angle through the first five-axis adjustment system (3) and the second five-axis adjustment system (10) so that they form a common optical axis (2).

[0099] S2, determine the relative positional relationship between the common optical axis (2) and the machining axis (11) by pre-drilling holes, standard holes, calibration targets, standard calibration plates or trial machining holes, and store the relative positional relationship in the control system.

[0100] S3, fix the material to be processed (6) on the shift stage (1) so that the first surface (5) faces the processing equipment (12), control the shift stage (1) to move the target hole (8) to the visual positioning position corresponding to the common optical axis (2), and collect images through the first camera device (4) and determine the position of the target hole (8) relative to the common optical axis (2).

[0101] S4. Based on the relative positional relationship between the common optical axis (2) and the machining axis (11), control the shifting stage (1) to move the target hole (8) to the machining position corresponding to the machining axis (11), and control the machining equipment (12) to perform the first segment machining from the first surface (5) to form the first hole segment.

[0102] S5, flip the material to be processed (6) so that the second surface (7) faces the processing equipment (12) and move the corresponding position of the first hole segment to the visual positioning position corresponding to the common optical axis (2).

[0103] S6, the image is acquired by the second camera device (9) and the position of the corresponding position of the first hole segment relative to the common optical axis (2) is determined; whether in-plane rotation angle correction or mirror path correction is required is determined according to the hole shape. The hole center is used for positioning of round holes or rotationally symmetric holes; the angle is determined by the main direction of the contour, the direction of the major axis, the direction of the minor axis, the characteristic corner point, the characteristic edge, or the direction of the line connecting the characteristic points; the mirror axis or mirror plane is determined according to the flipping direction of the irregular hole, and the second processing path is mirrored.

[0104] S7. Based on the relative positional relationship between the common optical axis (2) and the machining axis (11), the identification result of the second camera device (9), and the error compensation parameters, the shift stage (1) is controlled to move the corresponding position of the first hole segment to the machining position.

[0105] S8, control the processing equipment (12) to perform the second section processing from the second surface (7) so that the second hole section or through area (16) is connected with the first hole section to form a through hole.

[0106] Through the above implementation method, the first stage of processing and the second stage of processing are positioned based on the visual recognition results of the first camera device (4) and the second camera device (9), respectively, and the relative positional relationship between the common optical axis (2) and the processing axis (11) is used as the basis for coordinate transformation. For the translation error, angle error, mirror path change and motion mechanism error caused by the material flipping, the control system can correct them before the second stage of processing, so that the positive and negative holes correspond to each other in spatial position and processing path.

Claims

1. A double-sided drilling positioning device based on opposing dual-camera visual repositioning, characterized in that, include: The processing equipment (12) has a processing axis (11) for drilling or scanning the material (6) to be processed. A shifting stage (1) is used to carry and move the material to be processed, and the shifting stage has translational degrees of freedom in the X and Y directions in a unified spatial coordinate system and rotational degrees of freedom about the X and Y axes; a first five-axis adjustment system (3) and a first camera device (4), the first camera device being installed in the first five-axis adjustment system; The second five-axis adjustment system (10) and the second camera device (9) are installed on the second five-axis adjustment system. The first camera device and the second camera device are respectively set on opposite sides of the material to be processed. The first five-axis adjustment system and the second five-axis adjustment system both use the unified spatial coordinate system as the adjustment reference and both have translational adjustment degrees of freedom along the X, Y and Z directions and angular adjustment degrees of freedom around at least two intersecting axes. The angular adjustment degrees of freedom include at least pitch angle adjustment degrees of freedom and yaw angle adjustment degrees of freedom, so that the optical axis of the first camera device and the optical axis of the second camera device are coaxially aligned and form a common optical axis (2). The control system is connected to the processing equipment, the shifting stage, the first camera device, and the second camera device respectively. The control system is used to control the shifting stage and the processing equipment to complete the double-sided drilling and positioning processing of the material to be processed based on the relative positional relationship between the common optical axis and the processing axis, the image recognition results before and after the material to be processed is flipped over, and the movement parameters of the shifting stage. The control system is configured to determine the position of the target hole relative to the common optical axis before the material to be processed is flipped using the first camera device, determine the position of the corresponding position of the first hole segment after the material to be processed is flipped relative to the common optical axis using the second camera device, and determine the in-plane rotation angle and / or correction parameters of the second processing path after the material to be processed is flipped based on the hole shape.

2. The dual-sided drilling positioning device based on opposing dual-camera visual repositioning according to claim 1, characterized in that, The first camera device and the second camera device are each of a CCD camera, a CMOS camera, an industrial camera, a microscope camera, or a line scan camera. The resolution of the first camera device and the second camera device is from 300,000 pixels to 50 million pixels, the focal length of the lens is from 1 mm to 200 mm, the working distance is from 1 mm to 1000 mm, the depth of field is from 0.01 mm to 200 mm, the field of view is from 1° to 180°, the field of view range is from 0.1 mm × 0.1 mm to 1000 mm × 1000 mm, and the numerical aperture is from 0.01 to 0.

95.

3. The dual-sided drilling positioning device based on opposing dual-camera visual repositioning according to claim 1, characterized in that, The translation adjustment ranges of the first and second five-axis adjustment systems in the X, Y, and Z directions are ±0.01 mm to ±500 mm, respectively, and the rotation adjustment ranges around the pitch and yaw directions are ±0.01° to ±90°, respectively; the movement range of the shift stage in the X and Y directions is 0.1 mm to 3000 mm, respectively, and the rotation ranges around the X and Y axes are ±0.01° to ±90°, respectively; the processing equipment is any one of mechanical drilling equipment, laser drilling equipment, ultrasonic drilling equipment, electrical discharge machining equipment, milling equipment, or scanning processing equipment.

4. A method for positioning a double-sided borehole based on opposing dual-camera visual repositioning, characterized in that, Includes the following steps: The equipment includes a processing device (12), a shifting table (1), a first camera device (4), and a second camera device (9). The first camera device and the second camera device are respectively located on opposite sides of the material to be processed (6). The processing device has a processing axis (10). S1. Before processing the material to be processed, the first camera device and the second camera device are coaxially aligned so that the optical axis of the first camera device and the optical axis of the second camera device form a common optical axis (2). S2. Determine the relative positional relationship between the common optical axis and the machining axis, wherein the relative positional relationship is obtained by measurement through pre-drilling holes, standard holes, calibration targets, standard calibration plates, or trial machining holes; S3. The material to be processed is placed on the shifting stage, and the target hole (8) to be processed on the material to be processed is moved to the visual positioning position corresponding to the common optical axis; the first camera device is used to acquire an image of the target hole, and the position of the target hole relative to the common optical axis is determined based on the acquired image; S4. Based on the relative positional relationship between the common optical axis and the processing axis, control the shifting stage to move the target hole from the visual positioning position to the processing position corresponding to the processing axis; control the processing equipment to perform a first segment processing on the target hole from the first surface (5) of the material to be processed, so as to form a first hole segment; S5. After the first hole segment is formed, the material to be processed is flipped over by the shifting table or other flipping method so that the second surface (7) of the material to be processed faces the processing equipment, and the position of the first hole segment after flipping is moved to the visual positioning position corresponding to the common optical axis. S6. The second camera device acquires an image of the corresponding position of the first hole segment after flipping. Based on the acquired image, the position of the corresponding position of the first hole segment after flipping relative to the common optical axis is determined, and it is determined whether the relative angle of the material to be processed after flipping meets the preset processing requirements. When the hole to be processed is a circular hole or a rotationally symmetric hole, secondary positioning is performed based on the hole center position determined by the second camera device. When the hole to be processed is a hole with non-rotationally symmetric features, the in-plane rotation angle of the material to be processed after flipping is determined based on the edge contour, main contour direction, major axis direction, minor axis direction, feature corner point, feature edge, preset mark point, or the line direction connecting at least two feature points of the hole to be processed. Based on the in-plane rotation angle, the material to be processed is rotated and aligned, or the processing path direction of the second processing segment is corrected. When the hole to be processed is an irregular hole, the mirror change of the irregular hole position is determined based on the coordinate mirror relationship of the material to be processed after flipping, and the processing path of the second processing segment is mirror corrected. S7. After completing the secondary positioning through the second camera device, according to the relative positional relationship between the common optical axis and the processing axis, the shifting stage is controlled to move the position corresponding to the first hole segment after flipping from the visual positioning position to the processing position; S8. Control the processing equipment to perform a second segment of processing on the target hole from the second surface to form a second hole segment, and make the second hole segment communicate with the first hole segment to form a through hole.

5. The dual-sided drilling positioning method based on opposing dual-camera visual repositioning according to claim 4, characterized in that, In step S1, the coaxial alignment of the first camera device and the second camera device includes: 1A. A calibration component is provided between the first camera device and the second camera device, wherein the calibration component is a transparent calibration component with a marking pattern, a glass calibration component with a marking pattern, or a through-hole calibration component with a calibration through hole; 1B. Acquire images of the same marking pattern or the same calibration through-hole using the first camera device and the second camera device respectively, and identify the imaging center of the same marking pattern or the same calibration through-hole; 1C. Adjust the position, focus, pitch angle, and yaw angle of the first camera device and / or the second camera device so that the imaging center of the first camera device and the second camera device coincides with the imaging center of the same marking pattern or the same calibration through hole, or make the deviation between them less than a preset dual-camera calibration threshold, wherein the preset dual-camera calibration threshold is 0.1 μm to 500 μm.

6. The dual-sided drilling positioning method based on opposing dual-camera visual repositioning according to claim 4, characterized in that, Determining the relative positional relationship between the common optical axis and the machining axis in step S2 includes: 2A. Move the calibration material to the machining position corresponding to the machining axis and form a pre-drilled hole using the machining equipment; 2B. Move the pre-drilled hole to the visual positioning position corresponding to the common optical axis; acquire an image of the pre-drilled hole using the first camera device or the second camera device and determine the identification center of the pre-drilled hole; 2C. Based on the displacement of the calibration material when it moves from the processing position to the visual positioning position, determine the coordinate offset between the common optical axis and the processing axis in the X and / or Y directions, wherein the coordinate offset is from 0.01 mm to 3000 mm.

7. The dual-sided drilling positioning method based on opposing dual-camera visual repositioning according to claim 4, characterized in that, The diameter, equivalent diameter, circumscribed circle diameter, or maximum profile dimension of the hole to be processed is 0.01 mm to 300 mm; the length of the material to be processed is 1 mm to 3000 mm, the width is 1 mm to 3000 mm, and the thickness is 0.01 mm to 500 mm.

8. The dual-sided drilling positioning method based on opposing dual-camera visual repositioning according to claim 4, characterized in that, When the position of the target hole relative to the common optical axis is determined by the first camera device, and / or the position of the corresponding position of the first hole segment after flipping relative to the common optical axis is determined by the second camera device, the center, edge contour, gray center, geometric center, feature corner point, feature edge, main contour direction, major axis direction, minor axis direction, preset marker point, or the direction of the line connecting at least two feature points of the target hole or the corresponding position of the first hole segment are extracted, and the deviation between it and the image center corresponding to the common optical axis is determined according to the extraction result. The deviation is less than a preset visual positioning threshold, which is 0.1 μm to 1000 μm.

9. The dual-sided drilling positioning method based on opposing dual-camera visual repositioning according to claim 4, characterized in that, The processing depth of the first segment is less than the equivalent thickness of the material to be processed in the direction of the target hole axis, so that the first segment does not penetrate the material to be processed. The processing depth of the first segment is 1% to 99% of the equivalent thickness. The processing depth of the second segment is the depth that enables the second segment to communicate with the first segment and form a through hole. The overlap length of the first segment and the second segment in the direction of the target hole axis is 0.001 mm to 100 mm.

10. The double-sided drilling positioning method based on opposing dual-camera visual repositioning according to claim 4, characterized in that, Before moving the position corresponding to the first hole segment after flipping from the visual positioning position to the processing position, the movement parameters of the shifting stage and / or the processing path of the second segment are corrected according to at least one of the following: the flipping direction of the material to be processed, the relative positional relationship between the common optical axis and the processing axis, the reverse clearance of the shifting stage, the rotation angle error of the shifting stage, the thermal drift, the camera equipment calibration error, the axis runout error of the processing equipment, and the clamping error of the material to be processed. When the processing path of the second segment is mirrored, the mirror axis or mirror plane is determined according to the flipping direction of the material to be processed, and at least one of the path points, scanning direction, contour sequence, starting position and ending position in the first segment processing path is transformed according to the mirror axis or mirror plane. The processing equipment is controlled to perform the second segment processing according to the processing path after the coordinate transformation.

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