Door ring automatic splicing system and method

Abstract

The application relates to a door ring automatic splicing system, which comprises a visual positioning table with a positioning surface, a splicing tool provided with a plurality of target positions and corresponding target postures, a second material moving mechanism provided with a second grabbing component, a visual detection module and a controller; the visual detection module determines the actual plane posture of a workpiece on the positioning surface; the controller stores the standard plane posture, the standard grabbing state and the target placing state of the corresponding workpiece for each target position, corrects the standard grabbing state according to the deviation of the actual plane posture relative to the standard plane posture, controls the second material moving mechanism to grab the workpiece according to the actual grabbing state and run to the target placing state, so that the workpiece directly reaches the corresponding target position and is in the target posture, thereby reducing the secondary visual detection and translation and rotation adjustment on the side of the splicing tool, shortening the splicing beat, reducing the workpiece interference risk, improving the door ring splicing precision and consistency.

Description

Technical Field

[0001] This invention relates to the field of workpiece splicing, and in particular to an automatic door knocker splicing system and method. Background Technology

[0002] Automotive door rings are crucial structural components of car bodies, typically formed by sequentially splicing and welding multiple plate-shaped workpieces with different outer contours. Depending on the structural design of the door ring, the number of workpieces constituting it can be four, five, six, or more. To ensure subsequent welding quality, each workpiece must not only be in a predetermined splicing position before welding but also maintain a specified planar orientation. This ensures that the relative positions, relative deflection angles, and weld gaps between adjacent workpieces meet design requirements. Therefore, accurately placing and splicing multiple workpieces with initial position and orientation deviations to form the door ring to be welded is a critical step in the automated production process of door rings.

[0003] Existing automated door ring splicing systems typically include a loading area, a transfer robot, a splicing fixture, and a vision inspection device. The transfer robot picks up workpieces from the loading area and transfers them to the splicing fixture. Because there may be deviations in the initial position and posture of the workpiece in the loading area, and in the robot's actual gripping position, the workpiece usually cannot directly reach the predetermined splicing position and posture after being initially placed on the splicing fixture. Therefore, a common solution is to install a vision inspection device above the splicing fixture. This device detects the position and posture of the workpiece on the fixture, and then the transfer robot or an adjustment mechanism mounted on the fixture translates and rotates the workpiece on the fixture's bearing surface, gradually adjusting the workpiece to the corresponding target position and posture.

[0004] However, the above solutions require a visual inspection device above the splicing fixture to detect the placement of the workpiece, increasing the space occupied by the equipment, the workload of installation and calibration, and the complexity of the system. After the workpiece is placed on the splicing fixture, it also needs to undergo secondary translation and rotation, prolonging the splicing cycle of a single workpiece. Furthermore, when other workpieces are already placed on the splicing fixture, the adjustment process of the current workpiece on the bearing surface may cause spatial interference with the already placed workpieces. Therefore, there is an urgent need to propose an automatic door ring splicing system and method to solve the above problems. Summary of the Invention

[0005] The first objective of this invention is to provide an automatic door ring splicing system. This system can determine the actual planar pose of the workpiece before it enters the splicing fixture, and correct the standard gripping state of the second gripping component based on the planar pose deviation between the actual planar pose and the standard planar pose. This enables the second material transfer mechanism to accurately grip the workpiece from its actual planar pose and place it directly at the corresponding target position, placing the workpiece in the corresponding target posture. This reduces reliance on the visual inspection device above the splicing fixture, avoids secondary translation and rotation of the workpiece on the splicing fixture, and reduces the workpiece adjustment cycle time and the possibility of interference between the workpiece and the already placed workpiece.

[0006] The technical solution adopted by the present invention to solve the above problems is: an automatic door ring splicing system for splicing multiple workpieces to form a door ring to be welded, comprising: A vision positioning stage having a positioning surface for supporting the workpiece; The splicing fixture has a bearing surface for supporting multiple workpieces. The bearing surface has multiple target positions corresponding to each of the multiple workpieces. Each target position corresponds to a target posture. The target posture is a preset planar posture of the corresponding workpiece relative to the bearing surface when it is located at the target position. When each workpiece is located at its corresponding target position and in its corresponding target posture, they are spliced ​​together to form the door ring to be welded. The second material transfer mechanism includes a second gripping component for gripping the workpiece; A vision inspection module is used to determine the actual planar pose of the workpiece located on the vision positioning stage. The actual planar pose includes the actual position of the workpiece in the positioning surface and the actual planar pose of the workpiece relative to the positioning surface. The controller is communicatively connected to the vision detection module and the second material transfer mechanism, respectively; the controller stores the standard planar pose, standard gripping state and target placement state of the corresponding workpiece for each target position; The standard planar pose is the preset planar pose of the workpiece on the vision positioning stage. The standard planar pose includes the standard position of the workpiece in the positioning surface and the standard planar posture of the workpiece relative to the positioning surface. The standard gripping state is the position and orientation of the second gripping component in the execution coordinate system of the second material transfer mechanism when the second gripping component grips the workpiece in the standard planar pose on the vision positioning stage; The target placement state is the position and orientation of the second gripping component in the execution coordinate system of the second material transfer mechanism when the second gripping component grips the workpiece and holds the workpiece at the corresponding target position and in the corresponding target posture. The controller corrects the standard gripping state based on the planar pose deviation between the actual planar pose and the standard planar pose to obtain the actual gripping state, and controls the second material transfer mechanism to grip the workpiece according to the actual gripping state and then run to the target placement state to place the workpiece in the corresponding target position and make the workpiece in the corresponding target posture.

[0007] The beneficial effects of the embodiments of this invention are as follows: Since a vision positioning stage is used to support the workpiece to be assembled, the actual planar pose of the workpiece is determined by the vision detection module before it enters the assembly fixture. The controller stores the standard planar pose, standard gripping state, and target placement state of the corresponding workpiece for each target position. The standard gripping state is corrected based on the planar pose deviation between the actual planar pose and the standard planar pose to obtain the actual gripping state. Then, the second material transfer mechanism is controlled to grip the workpiece according to the actual gripping state and move it to the corresponding target placement state. Therefore, it is possible to compensate for the deviation of the initial position and initial planar pose of the workpiece during the gripping stage, ensuring that the workpiece is properly positioned. When placed on the splicing fixture, it can reach the corresponding target position and be in the corresponding target posture. This effectively solves the technical problems of existing technologies that require setting up a visual inspection device on top of the splicing fixture and performing secondary translation and rotation on the workpiece after initial placement. This leads to complex system layout, extended splicing cycle time, and easy interference between the workpiece and the already placed workpiece during the adjustment process. As a result, it can achieve one-time accurate grasping and positioning of the workpiece, reduce the dependence on the visual inspection and adjustment mechanism on the splicing fixture side, shorten the door ring splicing cycle time, reduce the possibility of spatial interference between workpieces, and improve the consistency and reliability of the splicing position and splicing posture of multiple workpieces.

[0008] The second objective of this invention is to provide an automatic door ring assembly method. This method can determine the actual planar pose of a workpiece on a vision positioning stage, correct the standard gripping state based on the planar pose deviation of the actual planar pose relative to the corresponding standard planar pose to obtain the actual gripping state, and control a second material transfer mechanism to grip the workpiece according to the actual gripping state and then move it to the corresponding target placement state, so that multiple workpieces accurately reach the corresponding target positions and are in the corresponding target postures, so as to be assembled together to form a door ring to be welded.

[0009] The technical solution adopted by the present invention to solve the above problems is, based on the above-mentioned automatic door ring splicing system, the automatic door ring splicing method includes: The actual planar pose of the workpiece located on the vision positioning stage is determined by the vision detection module. The controller corrects the corresponding standard grasping state based on the planar pose deviation between the actual planar pose and the corresponding standard planar pose to obtain the actual grasping state. The second material transfer mechanism is controlled to grasp the workpiece according to the actual grasping state and run to the corresponding target placement state, so as to place the workpiece in the corresponding target position and make the workpiece in the corresponding target posture; For each of the multiple workpieces, the actual planar pose is determined, the actual gripping state is determined, gripping and placement are performed, so that the multiple workpieces are spliced ​​together to form a door ring to be welded.

[0010] The beneficial effects of the embodiments of the present invention are as follows: Since the standard planar pose, standard gripping state, and target placement state of the corresponding workpiece are pre-stored for each target position, the actual planar pose of the workpiece on the vision positioning stage is determined by the vision detection module. The controller then corrects the standard gripping state based on the planar pose deviation between the actual planar pose and the corresponding standard planar pose to obtain the actual gripping state. Finally, the second material handling mechanism is controlled to grip the workpiece according to the actual gripping state and move it to the corresponding target placement state. Therefore, the deviation of the actual position and actual planar pose of the workpiece relative to the preset state can be compensated before the workpiece is gripped and transferred to the splicing fixture, ensuring that each workpiece is gripped and placed in the target position. When placed on the splicing fixture, it can reach the corresponding target position and be in the corresponding target posture. It effectively solves the technical problems of existing automatic door ring splicing methods, which are difficult to adapt to the initial position and initial posture deviation of the workpiece, and require re-inspection and translation or rotation adjustment after the initial placement of the workpiece. This leads to a longer splicing cycle, easy interference with the placed workpiece during the adjustment process, and insufficient splicing consistency. In this way, it can realize the one-time accurate grasping and positioning of multiple workpieces, reduce the secondary inspection and adjustment process on the splicing fixture side, shorten the door ring splicing cycle, reduce the possibility of spatial interference between workpieces, and improve the splicing accuracy, consistency and automation of the door ring to be welded. Attached Figure Description

[0011] Figure 1 A top view of an automatic door ring splicing system according to an embodiment of this application is shown.

[0012] Figure 2 A flowchart of an embodiment of the automatic door ring splicing method proposed in this application is shown.

[0013] Among them: 1. Vision positioning stage; 110. Positioning surface; 2. Assembly fixture; 210. Bearing surface; 211. Target position; 3. Second material transfer mechanism; 310. Second gripping component; 4. Vision inspection module; 5. Feeding mechanism; 510. Bearing platform; 6. First material transfer mechanism; 610. First gripping component; 7. Workpiece. Detailed Implementation

[0014] Example 1:

[0015] Existing automatic door ring splicing systems typically detect the position and orientation of workpiece 7 after it has been placed on splicing fixture 2, and then perform secondary translation and rotation adjustments on the splicing fixture 2. This can easily increase the complexity of equipment layout and splicing cycle time, and may cause interference between the workpiece 7 to be adjusted and the already placed workpiece 7.

[0016] To address the aforementioned shortcomings, this embodiment detects the actual planar pose of the workpiece 7 on the vision positioning stage 1 and corrects the gripping state based on the deviation between the actual planar pose and the standard planar pose, so that the workpiece 7 is directly placed to the corresponding target position 211 and target pose after being gripped.

[0017] This embodiment provides an automatic door ring splicing system, which splices multiple workpieces 7 to form a door ring to be welded. The workpieces 7 can be plate-shaped segments constituting the door ring, and different workpieces 7 can have different outer contours, dimensions, and splicing positions. The specific number of workpieces 7 is not limited; a corresponding number of workpieces 7 can be set according to the structure of the door ring to be welded. Please see Figure 1 The automatic door ring splicing system includes a vision positioning table 1, a splicing fixture 2, a second material transfer mechanism 3, a vision inspection module 4, and a controller.

[0018] The vision positioning stage 1 has a positioning surface 110 for supporting the workpiece 7, which serves to support the workpiece 7 before it is transferred to the splicing fixture 2 and to provide a relatively stable detection position for the vision inspection module 4 to detect the actual planar pose of the workpiece 7. The positioning surface 110 can be a plane that provides support for the workpiece 7, and when the workpiece 7 is placed on the positioning surface 110, its main extension direction is approximately parallel to the positioning surface 110. The vision positioning stage 1 can be positioned within the gripping range of the second material transfer mechanism 3, enabling the second material transfer mechanism 3 to grip the workpiece 7 from the positioning surface 110. The vision positioning stage 1 is also positioned within the detection range of the vision inspection module 4, enabling the vision inspection module 4 to acquire the position of the workpiece 7 within the positioning surface 110 and the planar pose of the workpiece 7 relative to the positioning surface 110. In this embodiment, the position of the workpiece 7 within the positioning surface 110 refers to the position of the workpiece 7 in a plane parallel to the positioning surface 110. The planar pose of the workpiece 7 relative to the positioning surface 110 refers to the planar angle formed after the workpiece 7 rotates around the normal of the positioning surface 110. The position of workpiece 7 within the positioning surface 110 and the planar orientation of workpiece 7 relative to the positioning surface 110 together constitute the planar orientation of workpiece 7.

[0019] The splicing fixture 2 has a bearing surface 210 for supporting multiple workpieces 7. The bearing surface 210 has multiple target positions 211 corresponding to each of the workpieces 7. That is, each workpiece 7 to be spliced ​​has a corresponding target position 211 on the bearing surface 210. The target position 211 defines a predetermined placement position of the corresponding workpiece 7 on the bearing surface 210. Each target position 211 corresponds to a target posture, which is a preset planar posture of the corresponding workpiece 7 relative to the bearing surface 210 when it is located at the target position 211. Specifically, it can be expressed as a preset planar angle of the workpiece 7 relative to the bearing surface 210. For the same workpiece 7, its target position 211 defines its position within the bearing surface 210, and its target posture defines its direction relative to the bearing surface 210. When each workpiece 7 is located at its corresponding target position 211 and in its corresponding target posture, a preset relative positional relationship and relative posture relationship are formed between the multiple workpieces 7, thereby jointly splicing them to form the door ring to be welded. Adjacent workpieces 7 can be adjacent to each other in a predetermined area to be welded, so that the connection position between multiple workpieces 7 can be welded subsequently.

[0020] The second transfer mechanism 3 includes a second gripping component 310 for gripping the workpiece 7, thereby gripping the workpiece 7 located on the vision positioning stage 1 and transferring it to the splicing fixture 2. The second transfer mechanism 3 can move the second gripping component 310 and adjust its position and orientation so that it can grip the workpiece 7 from the vision positioning stage 1 and transfer it to the splicing fixture 2. After establishing a gripping relationship with the workpiece 7, changes in the position and orientation of the second gripping component 310 can cause corresponding changes in the position and orientation of the workpiece 7. The second transfer mechanism 3 has an execution coordinate system. This execution coordinate system is used to describe the position and orientation of the second gripping component 310 during the operation of the second transfer mechanism 3. The position of the second gripping component 310 in the execution coordinate system can be used to characterize the spatial position of the second gripping component 310, and the orientation of the second gripping component 310 in the execution coordinate system can be used to characterize the directional state of the second gripping component 310 relative to the execution coordinate system. The second material transfer mechanism 3, according to the control command issued by the controller, causes the second gripping component 310 to move to the corresponding position and posture.

[0021] The vision inspection module 4 is used to determine the actual planar pose of the workpiece 7 located on the vision positioning stage 1. The actual planar pose includes the actual position of the workpiece 7 within the positioning surface 110 and the actual planar pose of the workpiece 7 relative to the positioning surface 110. The actual position represents the current position of the workpiece 7 within the positioning surface 110. The actual planar pose represents the current planar rotation angle of the workpiece 7 relative to the positioning surface 110. By detecting the current state of the workpiece 7 on the positioning surface 110, the vision inspection module 4 can output actual planar pose information corresponding to the actual position and actual planar pose.

[0022] The controller is communicatively connected to both the vision detection module 4 and the second material transfer mechanism 3. The vision detection module 4 can send the detected actual planar pose to the controller, which can generate corresponding control commands based on the actual planar pose and send the control commands to the second material transfer mechanism 3. The second material transfer mechanism 3 adjusts the position and orientation of the second gripping component 310 according to the control commands.

[0023] The controller stores the standard planar pose, standard gripping state, and target placement state of the corresponding workpiece 7 for each target position 211. For each workpiece 7, the controller saves a set of standard planar pose, standard gripping state, and target placement state corresponding to that workpiece 7. Thus, even if different workpieces 7 have different contours, target positions 211, or target postures, the controller can still call up the data corresponding to the current workpiece 7.

[0024] The standard planar pose is a preset planar pose of the workpiece 7 on the visual positioning stage 1. The standard planar pose includes the standard position of the workpiece 7 within the positioning surface 110 and the standard planar pose of the workpiece 7 relative to the positioning surface 110. The standard planar pose is a predetermined reference planar pose of the workpiece 7 relative to the positioning surface 110. The standard position and the standard planar pose together constitute the standard planar pose and serve as a comparison benchmark for judging whether the actual workpiece 7 has experienced positional shifts or attitude deflections relative to the preset state. The standard planar pose can be determined through reverse teaching. When the second material transfer mechanism 3 is a robotic arm and the second gripping component 310 is a vacuum negative pressure suction component, reverse teaching is existing technology and will not be elaborated upon here.

[0025] The standard gripping state refers to the position and orientation of the second gripping component 310 in the execution coordinate system of the second transfer mechanism 3 when the second gripping component 310 grips the workpiece 7 in the standard planar pose on the vision positioning stage 1. In other words, when the workpiece 7 is in the standard position and standard planar pose, the second gripping component 310 operates according to the standard gripping state, i.e., it can grip the workpiece 7 with a preset gripping relationship. The standard gripping state includes both the position and orientation of the second gripping component 310 in the execution coordinate system. The position of the second gripping component 310 is used to reach the preset gripping area of ​​the workpiece 7, and the orientation of the second gripping component 310 is used to establish a gripping relationship with the workpiece 7 in a preset direction.

[0026] The target placement state refers to the position and orientation of the second gripping component 310 in the execution coordinate system of the second material handling mechanism 3 when the second gripping component 310 grips the workpiece 7 and holds the workpiece 7 at the corresponding target position 211 and in the corresponding target posture. Therefore, the target placement state corresponds to the final placement state of the workpiece 7 on the splicing fixture 2. When the second gripping component 310 moves to the target placement state while holding the workpiece 7, the workpiece 7 held by the second gripping component 310 is located at the corresponding target position 211 and simultaneously in the corresponding target posture.

[0027] In actual production, the workpiece 7 to be assembled is first placed on the positioning surface 110 of the vision positioning stage 1. Since the actual position and actual planar orientation of the workpiece 7 may change each time it is placed on the positioning surface 110, the actual planar orientation of the workpiece 7 is usually not completely consistent with the standard planar orientation pre-stored in the controller.

[0028] The vision inspection module 4 inspects the current workpiece 7 on the positioning surface 110, determines the actual position and actual planar orientation of the workpiece 7, and sends these two as the actual planar pose to the controller. The controller then calls the standard planar pose, standard gripping state, and target placement state that match the current workpiece 7 and its corresponding target position 211.

[0029] The controller corrects the standard grasping state based on the planar pose deviation between the actual planar pose and the standard planar pose to obtain the actual grasping state.

[0030] The planar pose deviation is obtained by comparing the actual planar pose of workpiece 7 with the corresponding standard planar pose by the controller. The planar pose deviation can include the positional deviation of workpiece 7 within the positioning surface 110 and the planar pose deviation of workpiece 7 relative to the positioning surface 110. The positional deviation reflects the offset of the actual position of workpiece 7 relative to the standard position, and the planar pose deviation reflects the deflection of the actual planar pose of workpiece 7 relative to the standard planar pose. The actual gripping state is the position and pose that the second gripping component 310 should achieve in the execution coordinate system when gripping workpiece 7 in its actual planar pose. When the actual position of workpiece 7 deviates from the standard position, the controller correspondingly corrects the position in the standard gripping state; when the actual planar pose of workpiece 7 deflects relative to the standard planar pose, the controller correspondingly corrects the pose in the standard gripping state. Through these corrections, when the second gripping component 310 grips workpiece 7 according to the actual gripping state, it can form an actual gripping relationship corresponding to the preset gripping relationship with the current workpiece 7.

[0031] Subsequently, the controller controls the second material transfer mechanism 3 to grasp the workpiece 7 according to the actual grasping state and then run to the target placement state to place the workpiece 7 in the corresponding target position 211 and make the workpiece 7 in the corresponding target posture.

[0032] Since the actual gripping state has been corrected according to the actual planar pose of the workpiece 7, when the second gripping component 310 moves from the actual gripping state to the target placement state, it can compensate for the actual position deviation and actual planar pose deviation of the workpiece 7 on the vision positioning stage 1. As a result, after the workpiece 7 held by the second gripping component 310 is transferred to the splicing fixture 2, it can be located at the corresponding target position 211 and in the corresponding target pose.

[0033] For the remaining workpieces 7 that constitute the same gate ring to be welded, the above-described detection, deviation determination, gripping state correction, gripping, and placement processes can be performed separately. After each workpiece 7 is placed in its corresponding target position 211 and in its corresponding target posture, the multiple workpieces 7 together form the gate ring to be welded.

[0034] In this embodiment, the visual positioning station 1, the splicing fixture 2, and the second material transfer mechanism 3 can be arranged according to the actual production area, as long as the visual positioning station 1 is within the detection range of the visual inspection module 4, and both the visual positioning station 1 and the splicing fixture 2 are within the working range of the second material transfer mechanism 3. The positioning surface 110 of the visual positioning station 1 and the bearing surface 210 of the splicing fixture 2 can be set horizontally, or other arrangements that can stably support the workpiece 7 can be adopted according to the layout requirements of the production line.

[0035] This embodiment does not limit the number of workpieces 7 constituting the door ring to be welded, nor does it limit the specific outline shape of each workpiece 7. The number of target positions 211 and target postures can be set accordingly based on the number of workpieces 7. The second material transfer mechanism 3 can be a material transfer device capable of adjusting the position and posture of the second gripping component 310, preferably a robotic arm. The second gripping component 310 can be a gripping structure capable of stably gripping the plate-shaped workpiece 7, preferably a vacuum adsorption component. The vision inspection module 4 can be a vision inspection device capable of determining the actual position and actual planar posture of the workpiece 7. The controller can be set independently or integrated with the control device of the vision inspection module 4 or the second material transfer mechanism 3.

[0036] In this embodiment, the visual positioning stage 1 carries the workpiece 7 before it enters the splicing fixture 2, and the actual planar pose of the workpiece 7 is determined by the visual inspection module 4. The controller corrects the standard gripping state based on the planar pose deviation between the actual planar pose and the standard planar pose to obtain the actual gripping state. Then, the second material transfer mechanism 3 is controlled to grip the workpiece 7 according to the actual gripping state and move it to the target placement state. Therefore, this effectively solves the technical problems of the prior art, which requires visual inspection and secondary translation and rotation adjustment of the workpiece 7 after it has been initially placed in the splicing fixture 2. This leads to complex system layout, extended splicing cycle, and easy interference between the workpiece 7 and the already placed workpiece 7 during the adjustment process. As a result, the workpiece 7 can be accurately gripped and positioned in one go, reducing the dependence on the visual inspection device and adjustment mechanism on the splicing fixture 2 side, shortening the gate ring splicing cycle, reducing the possibility of spatial interference between workpieces 7, and improving the consistency and reliability of the splicing position and splicing posture of multiple workpieces 7.

[0037] Example 2:

[0038] Based on Example 1, in order to further establish the spatial correspondence between the image of workpiece 7 acquired by the visual inspection module 4 and the positioning surface 110 of the visual positioning stage 1, and to quantify the actual position, actual planar posture, and planar posture deviation of workpiece 7 relative to the standard planar posture, this example further explains the establishment of the positioning stage coordinate system, the identification of the contour of workpiece 7, and the determination of the feature points and feature directions of workpiece 7.

[0039] The positioning surface 110 is provided with multiple visual reference features. These features provide the vision inspection module 4 with fixed visual references that can be recognized in the image of the workpiece 7, establishing a coordinate correspondence between the image acquired by the vision inspection module 4 and the positioning surface 110. The visual reference features are fixedly set on the positioning surface 110, ensuring that their position relative to the vision positioning stage 1 remains unchanged during equipment operation. The visual reference features are structural features such as holes, grooves, and protrusions set on the positioning surface 110. Each visual reference feature can have the same shape or different shapes, as long as the vision inspection module 4 can recognize the position of each visual reference feature in the image.

[0040] The controller is configured to invoke a positioning stage coordinate system established based on multiple visual reference features, and the coordinate transformation relationship between the image coordinate system corresponding to the image acquired by the visual detection module 4 and the positioning stage coordinate system. The positioning stage coordinate system includes intersecting first and second coordinate axes, with the first direction and the second direction being the positive directions of the first and second coordinate axes, respectively. Specifically: The positioning stage coordinate system is established on the vision positioning stage 1 and maintains a fixed relative positional relationship with it. The first direction is the positive direction of the first coordinate axis of the positioning stage coordinate system, and the second direction is the positive direction of the second coordinate axis of the positioning stage coordinate system. The first and second coordinate axes together define the position coordinates within the positioning surface 110, so that any position within the positioning surface 110 can be represented by coordinate components along the first and second directions. The first and second coordinate axes are set according to the structural direction of the vision positioning stage 1, the main extension direction of the workpiece 7, or the equipment installation direction, and the first and second coordinate axes are perpendicular to each other to form a rectangular coordinate system, so as to respectively characterize the position components of the workpiece 7 in two orthogonal directions within the positioning surface 110.

[0041] The vision inspection module 4 determines the actual position and actual planar orientation of the workpiece 7 in the positioning table coordinate system based on the coordinate transformation relationship. Specifically: The image acquired by the vision inspection module 4 has a corresponding image coordinate system. The image coordinate system represents the position of each pixel, contour point, and visual reference feature in the image. The image coordinate system uses a preset point in the image as its origin and the horizontal and vertical axes of the image as its two coordinate directions. Coordinates in the image coordinate system are represented by pixel coordinates. Since the image coordinate system and the positioning table coordinate system belong to the image data and the actual positioning surface 110, respectively, the pixel positions in the image coordinate system cannot be directly used as the actual position of the workpiece 7 on the positioning surface 110. Therefore, during the equipment calibration stage, the vision inspection module 4 acquires a calibration image containing multiple visual reference features, identifies the image coordinates of each visual reference feature in the image coordinate system, and obtains the preset coordinates of each visual reference feature in the positioning table coordinate system. Based on the corresponding coordinates of the same visual reference feature in the two coordinate systems, a coordinate transformation relationship from the image coordinate system to the positioning table coordinate system is established. This coordinate transformation relationship is used to convert the position data in the workpiece 7 image into actual position data on the positioning surface 110. The coordinate transformation relationship can be stored in the form of a transformation matrix, calibration parameter set, mapping function, or coordinate correspondence table. The controller is configured to call the positioning stage coordinate system and coordinate transformation relationships. These relationships can be stored in the controller, the vision processing unit connected to the controller, or other storage devices, and can be called by the controller or vision processing unit during the inspection of workpiece 7. During calibration, coordinate transformation parameters can be obtained based on the image coordinates of multiple visual reference features and preset actual coordinates. When the imaging direction of the vision inspection module 4 is substantially perpendicular to the positioning surface 110, a correspondence between the image coordinates and the positioning stage coordinates can be established through planar coordinate transformation. When the vision inspection module 4 has an installation tilt angle relative to the positioning surface 110 or when the image exhibits perspective distortion, compensation for the installation tilt angle and perspective distortion can be made when establishing the coordinate transformation relationships. For lens distortion generated by the vision inspection module 4, distortion correction can also be performed on the workpiece 7 image based on predetermined lens calibration parameters before coordinate transformation.

[0042] Furthermore, the visual inspection module 4 includes an image acquisition unit and a visual processing unit, the visual processing unit being communicatively connected to the controller; the image acquisition unit is used to acquire an image of the workpiece 7 located on the visual positioning stage 1, and the visual processing unit is used to extract the actual edge contour of the workpiece 7 from the image of the workpiece 7, and determine the actual feature points and actual feature directions of the workpiece 7 based on the actual edge contour.

[0043] The image acquisition unit is used to acquire images of the workpiece 7 located on the vision positioning stage 1. The image acquisition unit is positioned above the positioning surface 110, with its imaging direction facing the positioning surface 110, and the workpiece 7 to be inspected is within the effective imaging range of the image acquisition unit. The installation position of the image acquisition unit should remain stable during production to avoid unexpected changes in the correspondence between the image coordinate system and the positioning stage coordinate system.

[0044] After acquiring an image of workpiece 7, the image acquisition unit transmits the image of workpiece 7 to the vision processing unit. The vision processing unit processes the image of workpiece 7 to extract the actual edge contour of workpiece 7. The actual edge contour is the contour of the outer edge of workpiece 7 in the image of workpiece 7 when it is currently in its actual planar pose. The vision processing unit can perform grayscale conversion, filtering, thresholding, edge detection, contour connection, and contour fitting on the image of workpiece 7 to obtain continuous actual edge contours. The above image processing method can adopt existing contour extraction methods, and this embodiment does not limit the specific processing algorithm.

[0045] The feature points of the actual workpiece 7 are used to characterize the actual position of the workpiece 7 within the positioning surface 110, and the feature directions of the actual workpiece 7 are used to characterize the actual planar orientation of the workpiece 7 relative to the positioning surface 110. For the same type of workpiece 7, the same feature point construction rules and feature direction selection rules are used in different production cycles to ensure that the actual planar orientations obtained in different production cycles have a consistent expression benchmark.

[0046] The vision processing unit determines the actual position of the workpiece 7 based on the coordinate transformation relationship and the coordinates of the feature points of the actual workpiece 7 in the positioning stage coordinate system. Specifically, it converts the coordinates of the feature points of the actual workpiece 7 in the image coordinate system to the coordinates of the feature points of the actual workpiece 7 in the positioning stage coordinate system, and determines the actual position of the workpiece 7 based on these coordinates. The actual position can be represented by the coordinate components of the feature points of the actual workpiece 7 along the first and second directions. The actual planar posture is determined based on the angle between the feature direction of the actual workpiece 7 and the first direction. Specifically, the vision processing unit also determines the actual planar posture of the workpiece 7 based on the angle between the feature direction of the actual workpiece 7 and the first direction. This angle can be calculated according to a preset positive angle direction. For example, the angle from the first direction to the feature direction of the actual workpiece 7 can be taken as the actual planar posture, and clockwise or counterclockwise directions can be predefined as the angle increase directions. Using a fixed positive angle direction allows the actual planar posture and the standard planar posture to have a unified angle expression rule.

[0047] The controller stores a standard position and a standard planar pose for the corresponding workpiece 7. The standard position is the coordinate of a preset feature point of workpiece 7 in the positioning stage coordinate system when workpiece 7 is in the standard planar pose. The preset feature point and the actual feature point of workpiece 7 use the same geometric construction rules, representing the positional state of the same workpiece 7's geometric feature in the standard planar pose and the actual planar pose, respectively. The standard planar pose is the angle between the preset feature direction of workpiece 7 and the first direction when workpiece 7 is in the standard planar pose. The preset feature direction and the actual feature direction of workpiece 7 use the same direction selection rules and the same positive angle direction. Therefore, the actual planar pose and the standard planar pose can be directly compared in angle.

[0048] The controller determines the coordinate difference between the actual position and the standard position in the first direction as the first position deviation, the coordinate difference between them in the second direction as the second position deviation, and the angle difference between the actual planar posture and the standard planar posture as the planar posture deviation. The planar posture deviation includes the first position deviation, the second position deviation, and the planar posture deviation. The first and second position deviations can be coordinate differences with positive and negative directions, reflecting the offset direction and amount of the workpiece 7 relative to the standard position along the first and second directions, respectively. The planar posture deviation can also be an angle difference with positive and negative directions, reflecting the deflection direction and amount of the workpiece 7 relative to the standard planar posture. The coordinate difference between the actual position and the standard position, and the angle difference between the actual planar posture and the standard planar posture, can be arranged in a unified data order to form planar posture deviation data and transmitted to the controller's grasping state correction program.

[0049] Furthermore, in order to ensure that the actual workpiece 7 feature points and the preset workpiece 7 feature points can be stably determined based on the contour of the workpiece 7 itself, the workpiece 7 has a first welding edge and a second welding edge that are spaced apart and do not intersect each other. The first welding edge and the second welding edge are two edges to be identified in the outer contour of the workpiece 7, which are spaced apart from each other on the contour of the workpiece 7 and do not intersect directly.

[0050] The first welding edge has a first endpoint and a second endpoint, and the second welding edge has a third endpoint and a fourth endpoint; the actual workpiece 7 feature point and the preset workpiece 7 feature point are the intersection points of the line connecting the first endpoint and the third endpoint and the line connecting the second endpoint and the fourth endpoint when the workpiece 7 is in the actual planar pose and the standard planar pose, respectively.

[0051] Specifically, each endpoint represents the contour boundary between the corresponding welded edge and the adjacent contour segment. In actual image processing, the vision processing unit can determine the first welded edge, the second welded edge, and each endpoint through methods such as straight line fitting, curve fitting, or contour turning point recognition. For workpiece 7 in its actual planar pose, after determining the first, second, third, and fourth endpoints in the actual edge contour, the vision processing unit establishes the lines connecting the first and third endpoints, as well as the lines connecting the second and fourth endpoints. The intersection of these two lines is determined as the actual workpiece 7 feature point. For workpiece 7 in its standard planar pose, the same endpoint correspondence is used to establish the lines connecting the first and third endpoints, as well as the lines connecting the second and fourth endpoints, and the intersection of these two lines is determined as the preset workpiece 7 feature point. The actual workpiece 7 feature points and the preset workpiece 7 feature points use the same endpoint combination and connection construction method; the only difference is that workpiece 7 is in its actual planar pose and standard planar pose, respectively.

[0052] The first welding edge, the second welding edge, and the four endpoints should be pre-determined according to a uniquely identifiable correspondence. For workpieces 7 of the same type, under both standard and actual planar poses, the first, second, third, and fourth endpoints correspond to the same physical contour position on workpiece 7, to avoid changes in feature point positions due to variations in endpoint correspondence. Preferably, the two connecting lines are not parallel to each other, so that they can form a unique intersection point. The actual feature points of workpiece 7 can be located within the solid area of ​​workpiece 7 or outside the area enclosed by the outer contour of workpiece 7, as long as they can be stably determined by the four endpoints and can be used to characterize the position of workpiece 7 in the positioning table coordinate system. Using feature points of workpiece 7 constructed from multiple contour endpoints can reduce the impact of local identification errors of a single contour endpoint on the actual position determination of workpiece 7.

[0053] The actual workpiece 7 feature direction and the preset workpiece 7 feature direction are the same preset direction when the workpiece 7 is in the actual planar pose and the standard planar pose, respectively. The preset direction is the direction from the first endpoint to the second endpoint or the direction from the third endpoint to the fourth endpoint.

[0054] Specifically, when the preset direction is selected as the direction from the first endpoint to the second endpoint, the actual feature direction of workpiece 7 is the direction from the actually identified first endpoint to the actually identified second endpoint when workpiece 7 is in the actual planar pose; the preset feature direction of workpiece 7 is the direction from the corresponding first endpoint to the corresponding second endpoint when workpiece 7 is in the standard planar pose. When the preset direction is selected as the direction from the third endpoint to the fourth endpoint, the actual feature direction of workpiece 7 is the direction from the actually identified third endpoint to the actually identified fourth endpoint when workpiece 7 is in the actual planar pose; the preset feature direction of workpiece 7 is the direction from the corresponding third endpoint to the corresponding fourth endpoint when workpiece 7 is in the standard planar pose. For workpieces of the same type, the same preset direction should be used in both the actual planar pose and the standard planar pose. For example, when the preset feature direction of workpiece 7 is the direction from the first endpoint to the second endpoint, the actual feature direction of workpiece 7 should also be the direction from the first endpoint to the second endpoint. This avoids inconsistencies in the positive directions of the actual and preset feature directions of workpiece 7, which could lead to angle calculation errors.

[0055] The coordinate calibration and visual recognition process in this embodiment can be completed before the automatic door ring splicing system is put into production. After the positioning table coordinate system and coordinate transformation relationship are established, it can be repeatedly called in multiple subsequent production cycles if the relative positions between the visual positioning table 1, the image acquisition unit and the visual reference features do not change.

[0056] In this embodiment, by establishing a fixed positioning table coordinate system and a coordinate transformation relationship between the image coordinate system and the positioning table coordinate system using multiple visual reference features set on the positioning surface 110, the image acquisition unit acquires the image of the workpiece 7, and the vision processing unit determines the actual feature points and actual feature directions of the workpiece 7 from the actual edge contour. Then, the actual position and actual planar posture of the workpiece 7 are represented by the feature point coordinates and the angle between the feature directions, respectively. The actual position and actual planar posture are compared with the standard position and standard planar posture determined by the same feature construction rules. Therefore, the technical problems of the image coordinates being difficult to directly and stably correspond to the actual position and actual planar posture of the workpiece 7 on the vision positioning table 1, and the lack of a unified comparison benchmark between the actual state and the standard state are effectively solved. Thus, the first position deviation, the second position deviation, and the planar posture deviation with clear directions and values ​​can be obtained, improving the accuracy, consistency, and repeatability of the planar posture detection and deviation calculation of the workpiece 7.

[0057] Example 3:

[0058] Based on Embodiment 1, in order to reliably fix the workpiece 7 after each workpiece 7 reaches the corresponding target position 211 and is in the corresponding target posture, and to avoid the second gripping component 310 releasing the grip and the positional shift or posture change of the placed workpiece 7 during the subsequent placement of the workpiece 7, the splicing fixture 2 in this embodiment is provided with multiple magnetic suction mechanisms corresponding one-to-one with the multiple target positions 211, and each magnetic suction mechanism is independently controlled and connected to the controller.

[0059] Each target position 211 of the bearing surface 210 on the splicing fixture 2, which carries multiple workpieces 7, corresponds to a magnetic attraction mechanism. The magnetic attraction mechanism is located in the bearing area of ​​the corresponding target position 211, preferably below the bearing surface 210. The attraction direction of the magnetic attraction mechanism is towards the corresponding target position 211, so that when the workpiece 7 is located at the corresponding target position 211, the magnetic attraction mechanism can apply a magnetic attraction force towards the bearing surface 210 to restrict the movement of the workpiece 7 relative to the bearing surface 210. A magnetic attraction mechanism includes one or more magnetic attraction units arranged at intervals. The controller can individually control any magnetic attraction mechanism to enter or de-attract from the attraction state without requiring other magnetic attraction mechanisms to operate synchronously. Each magnetic attraction mechanism can be connected to different control output terminals of the controller, and the controller can control each magnetic attraction mechanism through a drive circuit, switching device, or other control components. Thus, when the second transfer mechanism 3 is placing a workpiece 7, the controller can only activate the magnetic attraction mechanism corresponding to the target position 211 of that workpiece 7, while the magnetic attraction mechanisms corresponding to other target positions 211 can remain inactive. The magnetic attraction mechanism is preferably an electromagnetic attraction mechanism that generates magnetic attraction force when energized. In this embodiment, the controller switches the magnetic attraction mechanism between an attraction state and a non-attraction state by controlling the on / off state of the corresponding magnetic attraction mechanism.

[0060] The controller controls the second transfer mechanism 3 to place multiple workpieces 7 in the corresponding target positions 211 according to a preset splicing sequence, and to make each workpiece 7 in the corresponding target posture. When the second gripping component 310 keeps the current workpiece 7 in the corresponding target position 211 and in the corresponding target posture, the controller activates the magnetic suction mechanism corresponding to the target position 211. After the magnetic suction mechanism attracts and fixes the current workpiece 7, the controller controls the second gripping component 310 to release the grip on the current workpiece 7, and then controls the second transfer mechanism 3 to perform gripping and placement on the next workpiece 7.

[0061] Specifically, the controller stores a preset splicing order for multiple workpieces 7. This preset splicing order determines the order in which the multiple workpieces 7 are gripped and placed. The preset splicing order is pre-set based on the spatial relationship between the multiple workpieces 7, the overlapping relationship of adjacent workpieces 7, the outline shape of each workpiece 7, and the operating conditions of the second transfer mechanism 3. For multiple workpieces 7 constituting the same weldable door ring, the controller sequentially determines the current workpiece 7 according to the preset splicing order. The current workpiece 7 is the workpiece 7 that needs to be gripped and placed by the second transfer mechanism 3. After the current workpiece 7 is placed and magnetically fixed, the controller then determines the next workpiece 7 in the preset splicing order as the new current workpiece 7. During the placement of the workpiece 7, the controller controls the second transfer mechanism 3 to grip the current workpiece 7 through the second gripping component 310 and move the current workpiece 7 to the corresponding target position 211. Simultaneously, the second transfer mechanism 3 adjusts the position and orientation of the second gripping component 310 so that the current workpiece 7 is located at the corresponding target position 211 and in the corresponding target orientation.

[0062] After the second gripping component 310 moves the current workpiece 7 to the target position 211, it does not immediately release the grip on the current workpiece 7, but continues to hold the current workpiece 7. At this time, the position and orientation of the current workpiece 7 are maintained by the second gripping component 310, keeping the current workpiece 7 in the corresponding target position 211 and target orientation. This avoids the magnetic suction mechanism prematurely adsorbing the workpiece 7 before it is accurately in place. When the second gripping component 310 holds the current workpiece 7 in the corresponding target position 211 and in the corresponding target orientation, the controller activates the magnetic suction mechanism corresponding to the target position 211. The magnetic suction mechanism generates a magnetic force and adsorbs the current workpiece 7 onto the bearing surface 210 of the splicing fixture 2. Since the magnetic suction mechanism is activated after the current workpiece 7 has been held in the target position 211 and target orientation by the second gripping component 310, the magnetic suction mechanism is mainly used to maintain the already formed position and orientation of the workpiece 7, without needing to pull the workpiece 7 to move on the bearing surface 210 through magnetic attraction. After the magnetic attraction mechanism is activated, the second gripping component 310 can continue to grip the current workpiece 7 until it is confirmed that the magnetic attraction mechanism has achieved stable adsorption of the current workpiece 7. Whether the magnetic attraction mechanism has completed adsorption and fixation can be determined by a preset adsorption waiting time or by a signal fed back from the working status of the magnetic attraction mechanism. The above determination method can be selected according to the specific structure of the magnetic attraction mechanism and the system control requirements.

[0063] After the magnetic suction mechanism attracts and fixes the current workpiece 7, the controller controls the second gripping component 310 to release the grip on the current workpiece 7. When the second gripping component 310 releases the grip, the current workpiece 7 is held at the target position 211 and target posture by the corresponding magnetic suction mechanism, and therefore will not move unexpectedly as the second gripping component 310 leaves. After the second gripping component 310 releases the grip on the current workpiece 7, the controller controls the second transfer mechanism 3 to leave the current workpiece 7 and perform gripping and placement on the next workpiece 7 in the preset splicing sequence. For the next workpiece 7, similarly, when the second gripping component 310 holds the workpiece 7 at the corresponding target position 211 and in the corresponding target posture, the magnetic suction mechanism corresponding to the target position 211 is activated, and the grip is released after the magnetic suction mechanism attracts and fixes the workpiece 7.

[0064] During the subsequent grasping and placement of workpiece 7, each workpiece 7 that has been placed is held by its corresponding magnetic attraction mechanism. Since each magnetic attraction mechanism can be controlled independently, those that have been activated can continue to maintain their attraction state, while the magnetic attraction mechanism corresponding to the target position 211 where workpiece 7 has not yet been placed can remain inactive. This avoids premature attraction of workpiece 7 by its corresponding magnetic attraction mechanism before it has been accurately positioned.

[0065] After completing the current production stage, i.e. the welding structure of the door ring is finished, the controller can control each magnetic attraction mechanism to release the adsorption according to the subsequent operation requirements.

[0066] In this embodiment, multiple magnetic suction mechanisms, each corresponding to a target position 211 and independently controllable, are employed. The corresponding magnetic suction mechanism is activated when the second gripping component 310 holds the current workpiece 7 at the corresponding target position 211 and target posture. After the magnetic suction mechanism completes its adsorption and fixation, the second gripping component 310 releases its grip on the current workpiece 7. Multiple workpieces 7 are then placed and fixed sequentially according to a preset splicing order. This effectively solves the technical problems of unexpected adsorption caused by magnetic attraction before the workpiece 7 has accurately reached the target position 211 and target posture, and the easy positional shift or posture change of the workpiece 7 after the second gripping component 310 releases its grip. This achieves independent and reliable fixation of each workpiece 7 after it is in place, maintaining the preset relative position and posture between multiple workpieces 7, and improving the splicing stability, consistency, and subsequent processing accuracy of the door ring to be welded.

[0067] Example 4:

[0068] Based on Embodiment 1, in order to enable different types of workpieces 7 to enter the vision positioning stage 1 sequentially according to relatively fixed picking and placing positions, and to reduce random positional deviations of workpieces 7 during loading and transfer, the automatic door ring assembly system proposed in this embodiment further includes a loading mechanism 5 and a first transferring mechanism 6. The loading mechanism is used to store multiple workpieces 7 to be assembled, and the first transferring mechanism 6 is used to remove workpieces 7 from the loading mechanism 5 and transfer them to the preset placement area of ​​the vision positioning stage 1.

[0069] The feeding mechanism 5 includes at least one receiving platform 510, which has multiple fixed material picking positions. Each fixed material picking position is used to place multiple workpieces 7 of the same type corresponding to a target position 211.

[0070] The receiving platform 510 is used to support the workpieces 7 to be assembled and is located within the working range of the first transfer mechanism 6 so that the first transfer mechanism 6 can pick up the workpieces 7 from the receiving platform 510. The receiving platform 510 is a support structure such as a platform, rack, or pallet with a bearing surface. The fixed picking position is a pre-set storage position for the workpieces 7 on the receiving platform 510. Each fixed picking position corresponds to a type of workpiece 7 that constitutes the gate ring to be welded and corresponds to a target position 211 on the splicing fixture 2. The correspondence referred to here means that the workpiece 7 placed at the fixed picking position needs to be transferred to the corresponding target position 211 on the splicing fixture 2. Moreover, different fixed picking positions can be set in different areas of the same receiving platform 510 or can be set on multiple receiving platforms 510. The same fixed picking position is used to place multiple workpieces 7 of the same type corresponding to a target position 211. The same type of workpiece 7 refers to workpieces 7 with the same outer contour, size, and splicing purpose, and corresponding to the same target position 211 in the gate ring to be welded. Thus, each fixed material picking position forms a centralized material feeding position for a workpiece 7, and the first material transfer mechanism 6 can repeatedly pick up the same type of workpiece 7 from the fixed material picking position during continuous production.

[0071] The first transfer mechanism 6 includes a first gripping component 610 for gripping the workpiece 7. The first transfer mechanism 6 can move the first gripping component 610 and adjust its position and orientation so that it can grip the workpiece 7 from a fixed picking position and transfer it to the vision positioning stage 1. The first transfer mechanism 6 employs a transfer device capable of spatial position adjustment. The first gripping component 610 can adopt a corresponding gripping structure according to the shape, size, and surface condition of the workpiece 7, as long as it can stably hold the workpiece 7 during the transfer process. After the first gripping component 610 establishes a gripping relationship with the workpiece 7, changes in the position and orientation of the first transfer mechanism 6 can drive the workpiece 7 to move accordingly.

[0072] The first material transfer mechanism 6 is connected to the controller. This connection enables the controller to send motion control commands to the first material transfer mechanism 6 and control the first material transfer mechanism 6 to perform material picking, transferring, and releasing actions. The first material transfer mechanism 6 can also provide feedback to the controller on its current operating status, action completion status, or fault status, so that the controller can coordinate the continuous material feeding process.

[0073] The controller stores standard picking and standard placing states for each workpiece 7 corresponding to each target position 211. That is, each workpiece 7 has a standard picking state corresponding to its fixed picking position and a standard placing state corresponding to a preset placing area on the vision positioning stage 1. Different types of workpieces 7 can be configured with different standard picking and standard placing states.

[0074] The standard material handling state refers to the position and orientation of the first gripping component 610 when it grips the workpiece 7 located at the corresponding fixed material handling position. The position of the first gripping component 610 is used to ensure it reaches the preset gripping area of ​​the workpiece 7, and the orientation of the first gripping component 610 is used to ensure it establishes a gripping relationship with the workpiece 7 in a preset direction. The standard material handling state can be predetermined during equipment calibration or teaching.

[0075] The standard loading state refers to the position and orientation of the first gripping component 610 when it holds the workpiece 7 within the preset loading area of ​​the vision positioning stage 1. When the first gripping component 610 operates in the standard loading state, the workpiece 7 it holds can be placed within the preset loading area of ​​the vision positioning stage 1. The preset loading area is a pre-defined receiving area for the workpiece 7 on the vision positioning stage 1. This area does not require the workpiece 7 to be in the exact same precise position and orientation each time; it only needs to ensure that the workpiece 7 can be stably placed and meets the requirements of subsequent visual inspection and gripping. The same preset loading area can be set for different types of workpieces 7, or different preset loading areas can be set separately. The standard loading state can also be determined through pre-calibration or teaching.

[0076] During the actual material feeding process, the controller controls the first material transfer mechanism 6 to grasp the workpiece 7 from the fixed material picking position according to the corresponding standard material picking state, and to place the workpiece 7 in the preset material placement area according to the corresponding standard material placement state. That is, the controller first calls the standard material picking state and standard material placement state corresponding to the type of workpiece 7 that needs to be fed. Then, the controller controls the first material transfer mechanism 6 to move the first gripping component 610 to the corresponding fixed material picking position according to the standard material picking state, and grasp the workpiece 7 located at that fixed material picking position. After the first gripping component 610 completes the grasping, the controller controls the first material transfer mechanism 6 to transfer the workpiece 7 from the receiving platform 510 to the vision positioning platform 1. The first material transfer mechanism 6 operates according to the corresponding standard material placement state, so that the workpiece 7 held by the first gripping component 610 reaches the preset material placement area. Afterwards, the first gripping component 610 releases its grip on the workpiece 7, allowing the workpiece 7 to be placed on the vision positioning platform 1. After workpiece 7 is placed in the preset feeding area, the first transfer mechanism 6 can leave the vision positioning table 1 so that subsequent equipment can perform corresponding operations on workpiece 7. The controller then controls the first transfer mechanism 6 to pick up the next workpiece 7 from the corresponding fixed picking position according to the production cycle and the requirements of workpiece 7. By setting fixed picking positions, standard picking states, and standard feeding states for different types of workpieces 7, the first transfer mechanism 6 can repeatedly perform picking and feeding according to the preset path during continuous production, without having to re-search for the approximate position of workpiece 7 each time it is picked up, nor with having to redetermine the feeding position on the vision positioning table 1 each time it is fed.

[0077] Furthermore, multiple workpieces 7 of the same type are stacked vertically at their corresponding fixed pick-up positions. Multiple workpieces 7 can be stacked vertically to form a workpiece 7 pile, allowing the first transfer mechanism 6 to sequentially remove workpieces 7 from the top of the pile. The main extending planes of each workpiece 7 can be substantially parallel to each other and approximately parallel to the bearing surface of the receiving platform 510. The vertical direction refers to the stacking direction of the multiple workpieces 7. This direction is perpendicular to the bearing surface of the receiving platform 510. After the multiple workpieces 7 are stacked vertically, as the top workpiece 7 is removed one by one, the top position of the remaining workpiece 7 pile gradually decreases.

[0078] The controller stores the corresponding workpiece 7 thickness for each type of workpiece 7 and records the number of workpiece 7 that has been taken from the corresponding fixed picking position. The workpiece 7 thickness is the dimension of the workpiece 7 along the vertical stacking direction. For multiple workpieces 7 of the same type and with basically the same thickness, a preset thickness value can be used as the workpiece 7 thickness for that type of workpiece 7. Different types of workpieces 7 can have different workpiece 7 thicknesses, so the controller can store the thickness data corresponding to each type of workpiece 7 separately. The workpiece 7 thickness can be obtained from the workpiece 7 design data, or it can be measured and input into the controller before equipment calibration.

[0079] The controller also records the number of workpieces 7 that have been taken from the corresponding fixed pick-up position. This number indicates the number of workpieces 7 that the first transfer mechanism 6 has successfully taken since the current workpiece pile 7 was established or the number was reset. After a pick-up operation is successfully completed, the controller can increment the count of the workpieces 7 taken at the corresponding fixed pick-up position by one unit. When the fixed pick-up position is replenished with workpieces 7 or a new pile of workpieces 7 is replaced, the count of the taken workpieces 7 can be reset or reset according to the initial state of the new pile of workpieces 7.

[0080] The controller determines the material handling height compensation amount based on the product of the thickness of the workpiece 7 and the number of workpieces 7 that have been removed, and corrects the vertical position component in the corresponding standard material handling state based on the material handling height compensation amount.

[0081] Specifically, since multiple workpieces 7 of the same type are stacked vertically, the height of the top workpiece 7 changes as the number of workpieces 7 decreases. If the first transfer mechanism 6 always performs material handling according to the uncompensated standard material handling state, the first gripping component 610 may not be able to accurately reach the gripping position of the current top workpiece 7. Therefore, the controller determines a material handling height compensation amount based on the product of the thickness of the corresponding workpiece 7 and the number of workpieces 7 already removed from that fixed material handling position. The material handling height compensation amount characterizes the vertical height change of the current top workpiece 7 relative to the top workpiece 7 when the standard material handling state is determined. For example, in the standard material handling state where the top workpiece 7 of the initial stack of workpieces 7 is the material handling target, for each workpiece 7 removed, the top of the remaining stack of workpieces 7 decreases vertically by the thickness of one workpiece 7. When multiple workpieces 7 have been removed, the cumulative height change of the top of the stack of workpieces 7 corresponds to the product of the thickness of the workpiece 7 and the number of workpieces 7 already removed. The controller corrects the vertical position component in the corresponding standard material handling state based on the material handling height compensation amount. The vertical position component here refers to the coordinate component along the stacking direction of workpieces 7 in the position data included in the standard picking state. The controller compensates for the vertical position component while keeping other position components and attitude parameters in the standard picking state unchanged or substantially unchanged. The compensated picking state enables the first gripping component 610 to reach the top workpiece 7 of the current remaining stack of workpieces 7. The controller controls the first transfer mechanism 6 to operate according to the height-compensated picking state to grip the current top workpiece 7. The direction of the picking height compensation can be determined according to the positive direction of the vertical coordinates used by the system. When the top of the remaining stack of workpieces 7 decreases along the negative direction of the vertical coordinates after workpiece 7 is removed, the vertical coordinates in the standard picking state can be reduced accordingly based on the picking height compensation amount; when the system uses the opposite positive direction of the coordinates, compensation can also be performed according to the corresponding coordinate rules.

[0082] In one embodiment, the controller can perform continuous material handling according to the following process: First, it reads the standard material handling state of the corresponding workpiece 7, the thickness of the workpiece 7, and the number of workpieces 7 already handled; then, it determines the material handling height compensation amount based on the thickness of the workpiece 7 and the number of workpieces 7 already handled; then, it corrects the vertical position component in the standard material handling state based on the material handling height compensation amount, and controls the first material transfer mechanism 6 to grasp the workpiece 7 according to the corrected material handling state; after confirming that the workpiece 7 has been successfully handled, it updates the number of workpieces 7 already handled. When handling material from a new stack of workpieces 7 for the first time, the number of workpieces 7 already handled can be zero, at which time the material handling height compensation amount is zero, and the first material transfer mechanism 6 can perform material handling according to the standard material handling state. As the number of workpieces 7 already handled increases, the material handling height compensation amount increases accordingly, so that the material handling position of the first gripping component 610 gradually changes with the top position of the remaining stack of workpieces 7. The product of the thickness of the workpiece 7 and the number of workpieces 7 already handled can be directly used as the material handling height compensation amount, or the product can be corrected by considering the gap between workpieces 7, surface coating, or stacking compression. When the thickness of workpiece 7 is highly consistent and the stacking gap is small, compensation can be directly achieved by multiplying the thickness of workpiece 7 by the number of workpieces 7 already taken. Multiple workpieces 7 within the same fixed picking position are preferably stacked in the same orientation, ensuring that the preset gripping parts of each workpiece 7 are substantially aligned in the horizontal plane. Therefore, when workpieces 7 are taken away one by one, the first gripping component 610 mainly needs to compensate for vertical positional changes, without frequently altering its horizontal position and orientation.

[0083] In this embodiment, different types of workpieces 7 are placed in a centralized manner by a receiving platform 510 with multiple fixed picking positions. Standard picking and standard placing states are pre-stored for each type of workpiece 7. The controller controls the first material transfer mechanism 6 to complete the fixed position picking and preset area placing according to the corresponding state. At the same time, when multiple workpieces 7 of the same type are stacked vertically, the picking height compensation amount is determined according to the thickness of the workpiece 7 and the number of workpieces 7 that have been picked up. The vertical position component in the standard picking state is corrected by the compensation amount. Therefore, the technical problems of inconsistent feeding positions of different types of workpieces 7 and continuous changes in the top picking height after the stacked workpieces 7 are reduced one by one are effectively solved, which makes it difficult for the first gripping component 610 to pick up materials stably and accurately. Thus, the orderly feeding, repeated picking and placing, and adaptive compensation of stacking height of different types of workpieces 7 are realized, improving the accuracy, stability and automation of continuous feeding.

[0084] Example 5:

[0085] To improve the positional and orientation accuracy of multiple workpieces 7 on the splicing fixture 2, and to enable the multiple workpieces 7 to be accurately spliced ​​to form a door ring to be welded, this embodiment proposes an automatic door ring splicing method for an automatic door ring splicing system.

[0086] The automatic door ring splicing system includes a vision positioning table 1, a splicing fixture 2, a second material transfer mechanism 3, a vision inspection module 4, a controller, a material discharge mechanism, multiple magnetic suction mechanisms, and a welding mechanism. The vision positioning table 1 is used to support the workpiece 7 before it enters the splicing fixture 2. The vision inspection module 4 is used to detect the actual planar pose of the workpiece 7 on the vision positioning table 1. The second material transfer mechanism 3 is used to grasp the workpiece 7 and transfer it to the splicing fixture 2. The multiple magnetic suction mechanisms are used to fix the workpiece 7 at the corresponding target position 211 and target pose, respectively. The welding mechanism is used to weld the welds formed between the multiple workpieces 7.

[0087] Before executing the automatic door ring splicing method, standard planar poses, standard gripping states, target placement states, and standard contour templates can be pre-stored for each type of workpiece 7 constituting the door ring to be welded. The standard planar pose serves as a comparison reference for the planar pose of workpiece 7 on the vision positioning stage 1; the standard gripping state characterizes the position and posture of workpiece 7 when gripped by the second gripping component 310 in the standard planar pose; the target placement state characterizes the position and posture of workpiece 7 when held at the corresponding target position 211 and in the corresponding target posture by the second gripping component 310; and the standard contour template serves as a reference for detecting the contour dimensions of the corresponding type of workpiece 7. During the calibration stage, a positioning stage coordinate system and a coordinate transformation relationship from the image coordinate system to the positioning stage coordinate system can also be pre-established. The positioning stage coordinate system is established on the positioning surface 110 of the vision positioning stage 1 and includes intersecting first and second coordinate axes, with the first direction being the positive direction of the first coordinate axis. The image coordinate system is the coordinate system corresponding to the image acquired by the vision inspection module 4. The coordinate transformation relationship is used to convert the image coordinates obtained from the image of workpiece 7 into the actual coordinates of workpiece 7 on the positioning surface 110.

[0088] Please see Figure 2 The automatic door ring splicing method specifically includes the following steps: Step S100: The actual planar pose of the workpiece 7 located on the visual positioning stage 1 is determined by the visual inspection module 4.

[0089] The actual planar pose includes the actual position of the current workpiece 7 within the positioning surface 110 of the vision positioning stage 1 and the actual planar pose of the current workpiece 7 relative to the positioning surface 110. After the current workpiece 7 is placed on the vision positioning stage 1, its actual position and actual planar pose may deviate from the preset standard planar pose. The vision inspection module 4 inspects the current workpiece 7 before the second material handling mechanism 3 grasps it to obtain the actual planar pose that reflects the actual placement state of the current workpiece 7.

[0090] In this embodiment, step S100 may further include steps S110 and S120.

[0091] Step S110: The visual inspection module 4 acquires an image of the workpiece 7 located on the visual positioning stage 1, extracts the actual edge contour from the image of the workpiece 7, and compares the actual edge contour with the corresponding standard contour template to determine the contour size deviation of the workpiece 7.

[0092] In this process, when acquiring images of workpiece 7, the vision inspection module 4 can be controlled to acquire images after the current workpiece 7 has been placed on the vision positioning stage 1 and stabilized. The acquired image of workpiece 7 includes at least the outline to be identified of the current workpiece 7, so that the vision inspection module 4 can distinguish the current workpiece 7 from the vision positioning stage 1 from the image of workpiece 7. The vision inspection module 4 can preprocess the image of workpiece 7 and extract the actual edge contour from the processed image of workpiece 7. The actual edge contour is used to characterize the actual shape and contour size of the current workpiece 7. For workpieces of the same type 7, the actual edge contour and the corresponding standard contour template adopt the same contour expression rules. The controller or vision inspection module 4 calls the standard contour template corresponding to the type of the current workpiece 7 and compares the actual edge contour with the standard contour template to determine the contour size deviation of the current workpiece 7. In this step, the standard contour template serves as a comparison benchmark for whether the contour size of workpiece 7 is qualified, and does not directly replace the determination of the actual planar pose of the current workpiece 7. The contour size deviation is used to represent the difference between the actual edge contour of the current workpiece 7 and the standard contour template in terms of overall size or local contour size. The allowable range can be preset based on the manufacturing tolerance of the current workpiece 7, the splicing requirements between multiple workpieces 7, and the weld requirements between adjacent workpieces 7.

[0093] Step S120: When the contour size deviation exceeds the allowable range, control the feeding mechanism to move the workpiece 7 out of the vision positioning stage 1; when the contour size deviation is within the allowable range, determine the feature points and feature directions of the actual workpiece 7 according to the actual edge contour, determine the actual position of the workpiece 7 in the positioning surface 110 according to the coordinates of the feature points of the actual workpiece 7 in the positioning stage coordinate system based on the coordinates of the feature points of the actual workpiece 7, and determine the actual planar pose of the workpiece 7 relative to the positioning surface 110 according to the angle between the feature directions of the actual workpiece 7 and the first direction, and determine the actual planar pose of the workpiece 7 together with the actual position and the actual planar pose.

[0094] Specifically, when the contour dimension deviation exceeds the allowable range, it indicates that the contour dimension of the current workpiece 7 does not meet the preset requirements. At this time, the controller controls the material feeding mechanism to remove the current workpiece 7 from the vision positioning table 1, so that the workpiece 7 will not enter the subsequent gripping, placement, and splicing process. After the current workpiece 7 is discharged, the next workpiece 7 to be inspected can be placed on the vision positioning table 1, and steps S110 and S120 can be executed again. In this way, it can be avoided that workpieces 7 with unqualified contour dimensions are placed on the splicing fixture 2 and affect the splicing relationship and weld condition between adjacent workpieces 7.

[0095] When the contour dimension deviation is within the allowable range, it indicates that the current workpiece 7 meets the preset contour dimension requirements. The vision inspection module 4 determines the actual workpiece 7 feature points and the actual workpiece 7 feature direction based on the actual edge contour of the current workpiece 7. The actual workpiece 7 feature points are feature positions obtained according to the actual edge contour according to preset geometric determination rules, used to characterize the position of the current workpiece 7 within the positioning surface 110. The actual workpiece 7 feature direction is the direction obtained according to the actual edge contour according to preset direction determination rules, used to characterize the planar orientation of the current workpiece 7 relative to the positioning surface 110. The vision inspection module 4 determines the image coordinates of the actual workpiece 7 feature points in the workpiece 7 image, and converts the image coordinates into the coordinates of the actual workpiece 7 feature points in the positioning table coordinate system based on the coordinate transformation relationship from the image coordinate system to the positioning table coordinate system. The coordinates of the actual workpiece 7 feature points in the positioning table coordinate system are determined as the actual position of the current workpiece 7 within the positioning surface 110. The vision inspection module 4 also determines the angle between the actual workpiece 7 feature direction and the first direction, and determines this angle as the actual planar orientation of the current workpiece 7 relative to the positioning surface 110. The actual position and the actual planar pose together constitute the actual planar pose of the current workpiece 7. For workpieces 7 of the same type, the same rules for determining the actual workpiece 7 feature points, determining the actual workpiece 7 feature directions, and calculating angles should be used to ensure that the actual planar poses obtained in different production cycles have a unified expression benchmark.

[0096] Step S200: The controller corrects the corresponding standard grasping state based on the planar pose deviation between the actual planar pose and the corresponding standard planar pose to obtain the actual grasping state.

[0097] The controller first calls the corresponding standard planar pose, standard gripping state, and target placement state based on the type of the current workpiece 7 or the target position 211 corresponding to the workpiece 7. Then, the controller compares the actual planar pose obtained in step S100 with the corresponding standard planar pose. The planar pose deviation includes the position deviation of the current workpiece 7's actual position relative to the standard position, and the attitude deviation of the current workpiece 7's actual planar attitude relative to the standard planar attitude. The position deviation can include the offset of the current workpiece 7 along two intersecting directions within the positioning surface 110, and the attitude deviation can include the deflection angle of the current workpiece 7 about the normal of the positioning surface 110 relative to the standard planar attitude. The controller corrects the position and attitude in the standard gripping state according to the planar pose deviation. When the actual position of the current workpiece 7 translates relative to the standard position, the controller corrects the position in the standard gripping state according to the corresponding position deviation; when the actual planar attitude of the current workpiece 7 rotates relative to the standard planar attitude, the controller corrects the position and attitude in the standard gripping state according to the corresponding attitude deviation. The corrected actual gripping state is used to characterize the position and posture that the second gripping component 310 should achieve when gripping the workpiece 7, which is currently in the actual planar pose. After the second gripping component 310 grips the current workpiece 7 according to the actual gripping state, the relative positional relationship and relative posture relationship formed between the second gripping component 310 and the current workpiece 7 correspond to the preset gripping relationship when the workpiece 7 is in the standard planar pose and the second gripping component 310 grips the workpiece 7 according to the standard gripping state.

[0098] Therefore, even if the actual position and actual planar posture of the current workpiece 7 on the vision positioning stage 1 deviate from the standard planar posture, the second gripping component 310 can accurately grip the current workpiece 7 according to the corrected actual gripping state.

[0099] Step S300: Control the second material transfer mechanism 3 to grasp the workpiece 7 according to the actual grasping state, and run to the corresponding target placement state to place the workpiece 7 at the corresponding target position 211 and make the workpiece 7 in the corresponding target posture.

[0100] The target placement state is the position and orientation of the second gripping component 310 when it grips the current workpiece 7 and holds it at the corresponding target position 211 and in the corresponding target posture. Therefore, when the second gripping component 310 moves to the target placement state, the current workpiece 7 held by the second gripping component 310 can be located at the corresponding target position 211 on the splicing fixture 2 and in the target posture corresponding to that target position 211.

[0101] Since the second gripping component 310 has already corrected to the actual gripping state based on the actual planar pose of the current workpiece 7 during the gripping phase, a preset gripping relationship is formed between the second gripping component 310 and the current workpiece 7. Therefore, when the second gripping component 310 moves to the predetermined target placement state, it can compensate for the actual position deviation and actual planar pose deviation of the current workpiece 7 on the visual positioning stage 1, so that the current workpiece 7 directly reaches the corresponding target position 211 and target pose. Step S400: For each of the multiple workpieces 7, the actual planar pose is determined, the actual gripping state is determined, gripping and placement are performed respectively, so that the multiple workpieces 7 are spliced ​​together to form a door ring to be welded.

[0102] In step S400, when multiple workpieces 7 are gripped and placed sequentially according to a preset splicing order, the second gripping component 310 keeps the current workpiece 7 at the corresponding target position 211 and in the corresponding target posture, activates the magnetic suction mechanism corresponding to the target position 211, and after the magnetic suction mechanism attracts and fixes the current workpiece 7, controls the second gripping component 310 to release the gripping of the current workpiece 7, and then performs gripping and placement on the next workpiece 7; when multiple workpieces 7 are respectively located at the corresponding target position 211, in the corresponding target posture and fixed by the corresponding magnetic suction mechanism, controls the welding mechanism to weld the weld formed between adjacent workpieces 7 along a preset welding trajectory.

[0103] The controller can sequentially determine the current workpiece 7 according to a pre-stored preset splicing order. The preset splicing order is determined based on the relative positional relationship of multiple workpieces 7 in the door ring to be welded, the outer contour of each workpiece 7, and the adjacency relationship between workpieces 7.

[0104] For the current workpiece 7 in the preset splicing order, steps S100, S200 and S300 are executed sequentially. When the second gripping component 310 moves the current workpiece 7 to the corresponding target position 211 and puts the current workpiece 7 in the corresponding target posture, the second gripping component 310 continues to grip the current workpiece 7 and does not immediately release the grip.

[0105] While the second gripping component 310 holds the current workpiece 7 at the target position 211 and in the target posture, the controller activates the magnetic suction mechanism corresponding to the target position 211. The magnetic suction mechanism generates a magnetic attraction, adsorbing and fixing the current workpiece 7 onto the splicing fixture 2. The magnetic suction mechanism is activated after the current workpiece 7 has reached the target position 211 and the target posture, so that the magnetic suction mechanism is mainly used to maintain the current position and posture of the current workpiece 7, rather than pulling the current workpiece 7 on the splicing fixture 2 for unintended movement through magnetic attraction. After confirming that the magnetic suction mechanism has adsorbed and fixed the current workpiece 7, the controller controls the second gripping component 310 to release the grip on the current workpiece 7. After the second gripping component 310 releases the grip, the current workpiece 7 is held at the target position 211 and the target posture by the corresponding magnetic suction mechanism.

[0106] The controller then controls the second material transfer mechanism 3 to perform actual planar pose determination, actual gripping state determination, gripping, placement, and magnetic fixation on the next workpiece 7 in the preset splicing sequence. The magnetic attraction mechanism corresponding to the workpiece 7 that has been placed remains in the adsorption state, while the magnetic attraction mechanism corresponding to the workpiece 7 that has not yet been placed remains in the inactive state.

[0107] Multiple workpieces 7 are processed sequentially in the manner described above until all workpieces 7 constituting the door ring to be welded are located at their respective target positions 211, in their respective target postures, and fixed by their respective magnetic attraction mechanisms. At this point, a preset splicing relationship is formed between the multiple workpieces 7, and a weld seam to be welded is formed between adjacent workpieces 7.

[0108] After multiple workpieces 7 are spliced ​​and magnetically fixed, the controller controls the welding mechanism to move along a preset welding trajectory and weld the seams formed between adjacent workpieces 7. The preset welding trajectory corresponds to the position of the weld seams between each adjacent workpiece 7 in the door ring to be welded. The welding mechanism welds multiple seams sequentially according to a preset welding order. During the welding process, the magnetic attraction mechanism corresponding to each workpiece 7 can continue to maintain its attraction state to limit the positional displacement or posture change of each workpiece 7 during the welding process.

[0109] Using the above method, workpieces 7 whose contour dimensions exceed the allowable range are discharged before entering the splicing fixture 2. Workpieces 7 with qualified contour dimensions determine the corresponding actual gripping state according to their actual planar posture, and are directly placed to the target position 211 and target posture by the second material transfer mechanism 3. After multiple workpieces 7 are placed and magnetically fixed in sequence according to the preset splicing order, they are then welded along the preset welding trajectory, thereby realizing the detection, gripping compensation, accurate placement, sequential fixation and welding of multiple workpieces 7.

Claims

1. An automatic door ring splicing system for splicing multiple workpieces to form a door ring to be welded, characterized in that, include: A vision positioning stage having a positioning surface for supporting the workpiece; The splicing fixture has a bearing surface for supporting multiple workpieces. The bearing surface has multiple target positions corresponding to each of the multiple workpieces. Each target position corresponds to a target posture. The target posture is a preset planar posture of the corresponding workpiece relative to the bearing surface when it is located at the target position. When each workpiece is located at its corresponding target position and in its corresponding target posture, they are spliced ​​together to form the door ring to be welded. The second material transfer mechanism includes a second gripping component for gripping the workpiece; A vision inspection module is used to determine the actual planar pose of the workpiece located on the vision positioning stage. The actual planar pose includes the actual position of the workpiece in the positioning surface and the actual planar pose of the workpiece relative to the positioning surface. The controller is communicatively connected to the vision detection module and the second material transfer mechanism, respectively; the controller stores the standard planar pose, standard gripping state and target placement state of the corresponding workpiece for each target position; The standard planar pose is the preset planar pose of the workpiece on the vision positioning stage. The standard planar pose includes the standard position of the workpiece in the positioning surface and the standard planar posture of the workpiece relative to the positioning surface. The standard gripping state is the position and orientation of the second gripping component in the execution coordinate system of the second material transfer mechanism when the second gripping component grips the workpiece in the standard planar pose on the vision positioning stage; The target placement state is the position and orientation of the second gripping component in the execution coordinate system of the second material transfer mechanism when the second gripping component grips the workpiece and holds the workpiece at the corresponding target position and in the corresponding target posture. The controller corrects the standard gripping state based on the planar pose deviation between the actual planar pose and the standard planar pose to obtain the actual gripping state, and controls the second material transfer mechanism to grip the workpiece according to the actual gripping state and then run to the target placement state to place the workpiece in the corresponding target position and make the workpiece in the corresponding target posture.

2. The automatic door knocker splicing system according to claim 1, characterized in that: The positioning surface is provided with multiple visual reference features; The controller is configured to call a positioning stage coordinate system established based on multiple visual reference features, and the coordinate transformation relationship between the image coordinate system corresponding to the image acquired by the visual detection module and the positioning stage coordinate system. The positioning stage coordinate system includes an intersecting first coordinate axis and a second coordinate axis, and the first direction and the second direction are the positive directions of the first coordinate axis and the second coordinate axis, respectively. The vision inspection module determines the actual position and actual planar orientation of the workpiece in the positioning table coordinate system based on the coordinate transformation relationship.

3. The automatic door knocker splicing system according to claim 2, characterized in that: The visual detection module includes an image acquisition unit and a visual processing unit, and the visual processing unit is communicatively connected to the controller. The image acquisition unit is used to acquire a workpiece image of the workpiece located on the vision positioning stage, and the vision processing unit is used to extract the actual edge contour of the workpiece from the workpiece image, and determine the actual workpiece feature points and the actual workpiece feature direction based on the actual edge contour. The vision processing unit determines the actual position based on the coordinate transformation relationship and the coordinates of the actual workpiece feature points in the positioning table coordinate system, and determines the actual planar posture based on the angle between the actual workpiece feature direction and the first direction. The standard position is the coordinate of a preset workpiece feature point in the positioning table coordinate system when the corresponding workpiece is in the standard plane pose; the standard plane pose is the angle between the preset workpiece feature direction and the first direction when the corresponding workpiece is in the standard plane pose. The controller determines the coordinate difference between the actual position and the standard position in the first direction as the first position deviation, the coordinate difference between the two in the second direction as the second position deviation, and the angle difference between the actual planar attitude and the standard planar attitude as the planar attitude deviation. The planar pose deviation includes the first position deviation, the second position deviation, and the planar pose deviation.

4. The automatic door knocker splicing system according to claim 3, characterized in that: The workpiece has a first welding edge and a second welding edge that are spaced apart and do not intersect each other. The first welding edge has a first end point and a second end point, and the second welding edge has a third end point and a fourth end point. The actual workpiece feature point and the preset workpiece feature point are the intersection points of the lines connecting the first endpoint and the third endpoint and the second endpoint and the fourth endpoint, respectively, when the workpiece is in the actual planar pose and the standard planar pose. The actual workpiece feature direction and the preset workpiece feature direction are the same preset direction when the workpiece is in the actual planar pose and the standard planar pose, respectively. The preset direction is the direction from the first endpoint to the second endpoint or the direction from the third endpoint to the fourth endpoint.

5. The automatic door knocker splicing system according to claim 1, characterized in that: The splicing fixture is equipped with multiple magnetic attraction mechanisms that correspond one-to-one with the multiple target positions, and each of the magnetic attraction mechanisms is independently controlled and connected to the controller. The controller controls the second material transfer mechanism to place multiple workpieces in the corresponding target positions in a preset splicing order and to make each workpiece be in the corresponding target posture. When the second gripping component keeps the current workpiece in the corresponding target position and in the corresponding target posture, the controller activates the magnetic suction mechanism corresponding to the target position, and after the magnetic suction mechanism attracts and fixes the current workpiece, it controls the second gripping component to release the gripping of the current workpiece, and then controls the second transfer mechanism to perform gripping and placement on the next workpiece.

6. The automatic door knocker splicing system according to claim 1, characterized in that, Also includes: The feeding mechanism includes at least one receiving platform, which has multiple fixed material picking positions, each of which is used to place multiple workpieces of the same type corresponding to a target position. The first material transfer mechanism includes a first gripping component for gripping the workpiece, and the first material transfer mechanism is connected to the controller; The controller stores standard picking state and standard placing state for each workpiece corresponding to each target position. The standard picking state is the position and posture of the first gripping component when it picks up the workpiece located at the corresponding fixed picking position. The standard placing state is the position and posture of the first gripping component when it holds the workpiece in the preset placing area of ​​the vision positioning table. The controller controls the first material transfer mechanism to pick up the workpiece from the fixed material pick-up position according to the corresponding standard material pick-up state, and to place the workpiece in the preset material release area according to the corresponding standard material release state.

7. The automatic door knocker splicing system according to claim 6, characterized in that: Multiple workpieces of the same type are stacked vertically at their corresponding fixed material handling positions; The controller stores the corresponding workpiece thickness for each type of workpiece and records the number of workpieces that have been taken away from the corresponding fixed material picking position. The controller determines the material handling height compensation amount based on the product of the workpiece thickness and the number of workpieces already taken away, and corrects the vertical position component in the corresponding standard material handling state based on the material handling height compensation amount.

8. An automatic door knocker splicing method, applied to an automatic door knocker splicing system, characterized in that: The automatic door ring splicing system includes a vision positioning table, a splicing fixture, a second material transfer mechanism, a vision inspection module, and a controller. The vision positioning table has a positioning surface for carrying workpieces, and the splicing fixture has a bearing surface for carrying multiple workpieces. The bearing surface has multiple target positions corresponding to the multiple workpieces, and each target position corresponds to a target posture. The second material transfer mechanism includes a second gripping component for gripping the workpieces. The controller stores the standard planar posture, standard gripping state, and target placement state of the corresponding workpiece for each target position. The standard planar posture is a preset planar posture of the corresponding workpiece on the vision positioning table. The standard gripping state is the position and posture of the second gripping component in the execution coordinate system of the second material transfer mechanism when the second gripping component grips the corresponding workpiece on the vision positioning table in the standard planar posture. The target placement state is the position and posture of the second gripping component in the execution coordinate system when the second gripping component grips the corresponding workpiece and holds the corresponding workpiece in the corresponding target position and in the corresponding target posture. The automatic door ring splicing method includes: The actual planar pose of the workpiece located on the vision positioning stage is determined by the vision detection module. The controller corrects the corresponding standard grasping state based on the planar pose deviation between the actual planar pose and the corresponding standard planar pose to obtain the actual grasping state. The second material transfer mechanism is controlled to grasp the workpiece according to the actual grasping state and run to the corresponding target placement state, so as to place the workpiece in the corresponding target position and make the workpiece in the corresponding target posture; For each of the multiple workpieces, the actual planar pose is determined, the actual gripping state is determined, gripping and placement are performed, so that the multiple workpieces are spliced ​​together to form a door ring to be welded.

9. The automatic door knocker splicing method according to claim 8, characterized in that: The positioning surface is provided with multiple visual reference features. During the calibration stage, a positioning stage coordinate system is established based on the multiple visual reference features, as well as the coordinate transformation relationship between the image coordinate system corresponding to the image acquired by the visual detection module and the positioning stage coordinate system. The positioning stage coordinate system includes intersecting first and second coordinate axes, with the first direction being the positive direction of the first coordinate axis. The controller stores a standard contour template for each target position, which serves as a comparison benchmark for detecting the contour dimensions of the corresponding workpiece. In the actual production process, the vision inspection module acquires the workpiece image located on the vision positioning stage, extracts the actual edge contour from the workpiece image, and compares the actual edge contour with the corresponding standard contour template to determine the contour size deviation of the workpiece. When the deviation of the contour size exceeds the allowable range, the control feeding mechanism moves the workpiece out of the vision positioning table; When the contour size deviation is within the allowable range, the actual workpiece feature points and the actual workpiece feature direction are determined according to the actual edge contour. Based on the coordinate transformation relationship, the actual position of the workpiece in the positioning surface is determined according to the coordinates of the actual workpiece feature points in the positioning table coordinate system. The actual planar pose of the workpiece relative to the positioning surface is determined according to the angle between the actual workpiece feature direction and the first direction. The actual position and the actual planar pose are jointly determined as the actual planar pose.

10. The automatic door knocker splicing method according to claim 8, characterized in that: The splicing fixture is equipped with multiple magnetic suction mechanisms that correspond one-to-one with the multiple target positions and can be independently controlled; According to the preset splicing order, multiple workpieces are grasped and placed sequentially. When the second grasping component keeps the current workpiece in the corresponding target position and in the corresponding target posture, the magnetic suction mechanism corresponding to the target position is activated. After the magnetic suction mechanism attracts and fixes the current workpiece, the second grasping component is controlled to release the grasp of the current workpiece, and then the next workpiece is grasped and placed. When multiple workpieces are respectively located at the corresponding target positions, in the corresponding target postures, and fixed by the corresponding magnetic attraction mechanisms, the welding mechanism is controlled to weld the weld seam formed between adjacent workpieces along a preset welding trajectory.

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