Bending structure defect electron beam fuse repair manufacturing control system and method

Abstract

The invention relates to a bending structure defect electron beam fuse repair manufacturing control system and method, a wire feeder sends out a welding wire along the central axis of an electron beam welding gun, an XYZ-axis moving platform is in threaded connection with the electron beam welding gun, and the pose of the welding gun is adjusted in real time according to the defect position change in the electron beam machining process; the mechanical arm adjusts the space poses of the camera and the XYZ-axis moving platform in the manufacturing process; the control device acquires image information of the damage defect in real time by controlling the camera, and extracts the position, contour shape and thickness characteristics of the damage defect; the pose of the electron beam welding gun is adjusted in real time by controlling the mechanical arm and the XYZ-axis moving platform, and the electron beam size, the electron beam spot position and the wire feeding speed are adjusted in real time by controlling the electron beam power source and the wire feeder. The spacecraft structure damage defects are identified and classified according to shape and size differences, and different processes are selected for defect repair, so that the safety of long-term on-orbit spacecrafts is ensured.

Description

Technical Field

[0001] This invention belongs to the field of on-orbit processing and manufacturing technology of metallic materials, and relates to a manufacturing control system and method for repairing bent structural defects with electron beam filament. Background Technology

[0002] Space stations, probes, and other long-term orbiting spacecraft face serious damage risks due to space debris and meteorite particles. To ensure that the lifespan and functional indicators of spacecraft meet design requirements, it is urgent to study on-orbit repair technologies for metal structure damage.

[0003] The shape and size of spacecraft impact damage are influenced by factors such as the volume, velocity, and angle of impact of the object. The outline of impact damage is usually an irregular, bent shape. To ensure the quality of defect repair, defects should be classified according to their shape and size, and different repair processes should be selected for different types of defects.

[0004] Electron beam technology has advantages such as high energy utilization, flexible beam control, and good adaptability to vacuum environments. It can perform various operations on metal materials in space, such as welding, cutting, and additive manufacturing, and has broad application prospects in the field of on-orbit repair and manufacturing of spacecraft. Summary of the Invention

[0005] The technical problem solved by this invention is to propose an electron beam filament repair manufacturing control system and method for irregular bending profile damage caused by factors such as space debris impacts. The system identifies and classifies spacecraft structural damage defects based on differences in shape and size, and selects different processes to repair defects of different types, thereby ensuring the safety of spacecraft in orbit for a long time.

[0006] The solution to the technical problem of this invention is: a manufacturing and control system for repairing bent structural defects by electron beam welding, comprising an XYZ axis moving platform, a monitoring camera, a coaxial wire feeding electron beam welding gun, a wire feeder, a control device, an electron beam power supply, and a robotic arm;

[0007] The wire feeder is screwed to the coaxial wire feeding electron beam welding gun, which feeds the welding wire along the central axis of the electron beam welding gun.

[0008] The XYZ axis moving platform is screwed to the coaxial wire feeding electron beam welding gun. During the electron beam processing, the position of the welding gun is adjusted in real time according to the change of the defect position to ensure the accuracy of trajectory movement and the stability of focal length.

[0009] The monitoring camera and the XYZ axis moving platform are connected to the robotic arm, which is used to adjust the spatial pose of the monitoring camera and the XYZ axis moving platform during the manufacturing process.

[0010] The control device is connected to the monitoring camera, robotic arm, XYZ axis moving platform, electron beam power supply and wire feeder via 1553B bus. During the processing, it controls the monitoring camera to acquire image information of damage defects in real time and extract the location, contour shape and thickness features of damage defects. It controls the robotic arm and XYZ axis moving platform to adjust the pose of the electron beam welding gun in real time, and controls the electron beam power supply and wire feeder to adjust the electron beam current, electron beam spot position and wire feed speed in real time.

[0011] Furthermore, the Z-axis of the XYZ axis moving platform is parallel to the central axis of the electron beam welding gun.

[0012] Furthermore, the monitoring camera and the XYZ axis moving platform are both mounted at the end of the robotic arm.

[0013] A manufacturing control method for repairing bent structural defects using electron beam filaments includes the following steps:

[0014] S1. Use a monitoring camera to acquire image information of damage and defects, and use image processing algorithms to obtain the location, contour shape and thickness features of damage and defects;

[0015] S2. Under the same repair process parameters, let the width of a single weld formed by an electron beam welding gun on a flat plate be B, and the thickness be T. Classify the defects according to the area and thickness of the defect damage:

[0016] When the defect thickness t is less than or equal to the single weld thickness T, it is defined as a small thickness defect; when t is greater than T, it is defined as a large thickness defect.

[0017] When the defect width b is less than or equal to the width B of a single weld, it is defined as a small defect; when the defect width b is in the range of B to 1.5B, it is defined as a medium defect; and when b is greater than or equal to 1.5B, it is defined as a large defect.

[0018] S3. Determine the repair process based on the type of damage / defect:

[0019] For defects with small thickness and small size, electron beam welding is selected for repair based on the generated welding torch motion trajectory.

[0020] For defects with small thickness and medium size, an electron beam welding process using an oscillating welding gun is selected for repair based on a zigzag oscillation path.

[0021] For defects with small thickness and large size, the first step is to use electron beam cutting technology to prepare repair parts that match the shape of the damaged defect. Then, the repair parts are welded to the defect location using electron beam welding technology for repair.

[0022] For defects with large thickness, electron beam wire bonding is used to repair the defects in a multi-layer deposition manner. The repair process of each layer in the multi-layer deposition is the same as the repair process of large, medium and small size defects with small thickness.

[0023] Furthermore, the method for generating welding torch movement trajectories for small-thickness, small-size defects is as follows:

[0024] ① Use the centerline skeleton extraction algorithm to obtain the centerline of the damage defect contour, identify and calculate the curvature radius values ​​at different positions of the centerline, and mark the positions of the numerical change points;

[0025] ② When the distance d between numerical change points is less than the width B of a single weld, the midpoint of the two points is used instead of the two points;

[0026] ③ Calculate and merge the remaining numerical mutation points according to step ② until there is at most one point in each segment of length D of the center line. Use this point as the endpoint to divide the center line into segments and connect the endpoints with straight lines to form a regular trajectory composed of straight lines. Here, D is a constant value selected based on engineering experience, and the minimum value of D is greater than B.

[0027] Furthermore, for the broken-line oscillation path of small-thickness, medium-sized defects, the oscillation amplitude is set to 0.6 to 0.7 times the average width of the defect, and the oscillation length is 0.3 to 0.5 times the oscillation amplitude.

[0028] Furthermore, the method for generating welding torch movement trajectories for small-thickness, large-size defects is as follows:

[0029] ① Identify and calculate the radius of curvature values ​​at different positions of the damage defect contour line, mark the positions of the numerical change points, and when the distance d between the numerical change points is less than the width B of a single weld, use the midpoint of the two points to replace the two points.

[0030] ② Following step ①, calculate and merge the remaining numerical mutation points until there is at most one point within the range of each segment length D of the contour line. Use this point as the endpoint to divide the contour line into segments, and connect the endpoints with straight lines to form a regular figure composed of straight lines; where the minimum value of the constant D is greater than B.

[0031] ③ The welding torch movement trajectory at the bending position of the forming path is optimized by using a transition arc to ensure the smoothness and continuity of the welding torch movement during the repair process.

[0032] Furthermore, the minimum radius of curvature of the transition arc is greater than 0.5B.

[0033] Furthermore, when repairing defects and damage of small thickness and large size:

[0034] According to the generated welding torch movement trajectory, the damage defect contour is trimmed by electron beam cutting process to remove the curling defect and make the damage defect contour into a regular shape composed of straight lines.

[0035] The repair parts are obtained by using electron beam cutting technology, based on the proportionally magnified motion trajectory of the welding torch.

[0036] Electron beam welding is used to repair defects by following the same welding torch movement trajectory as the parts being cut and repaired.

[0037] Furthermore, the area of ​​the repaired part is larger than the outline of the damage defect, the distance between the outline of the repaired part and the outline of the damage defect is 0.5 to 2.0 mm, and the magnification ratio of the welding torch movement trajectory corresponding to cutting the repaired part and trimming the outline of the damage defect is 1.01 to 1.1 times.

[0038] The advantages of this invention compared to the prior art are:

[0039] This invention addresses the irregular bending contour damage caused by factors such as space debris impacts. It establishes a quantifiable and universally applicable damage defect classification method, and then identifies and classifies spacecraft structural damage defects based on differences in shape and size. Different welding processes and different welding torch trajectory generation methods are selected for different types of defects to repair them, and the welding torch movement trajectory is optimized during the repair process. This on-orbit repair technology greatly ensures the safety of spacecraft in orbit for long periods of time. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the electron beam fuse repair manufacturing control system of the present invention;

[0041] Figure 2 This is a flowchart illustrating the defect classification and repair process selection for this invention.

[0042] Figure 3(a) is a schematic diagram of the welding torch motion trajectory generation for small-thickness, small-size defects;

[0043] Figure 3(b) shows the extracted welding torch trajectory;

[0044] Figure 4 The zigzag oscillating motion trajectory of the welding torch for small-thickness, medium-sized defects;

[0045] Figure 5 A schematic diagram of optimized welding torch movement trajectory for small-thickness, large-size defects;

[0046] Figure 6 A schematic diagram is generated for the motion trajectory of a welding torch with a regular shape.

[0047] Figure 7This is a schematic diagram illustrating the optimization of the welding torch movement path at the bending position using a transition arc.

[0048] Figure 8 To cut and prepare the repair parts and compare them with the defect contours. Detailed Implementation

[0049] The invention will now be further described with reference to the accompanying drawings.

[0050] like Figure 1 As shown, the present invention proposes a manufacturing control system for repairing bent structural defects by electron beam welding, which includes an XYZ axis moving platform, a monitoring camera, a coaxial wire feeding electron beam welding gun, a wire feeder, a control device, an electron beam power supply, and a robotic arm.

[0051] The wire feeder is connected to the coaxial wire feeding electron beam welding gun by bolts. The welding wire is concentric with the central axis of the coaxial wire feeding electron beam welding gun. The wire feeder feeds the welding wire along the central axis of the electron beam welding gun, which effectively reduces the difficulty of planning the movement path of the welding gun when forming and manufacturing complex components, and improves the forming quality of the components.

[0052] The coaxial wire-feeding electron beam welding gun is connected to the XYZ axis moving platform by bolts. The Z-axis of the XYZ axis moving platform is parallel to the central axis of the electron beam welding gun. The XYZ axis moving platform is used to adjust the position of the welding gun in real time according to the changes in the defect position during electron beam processing, so as to ensure the trajectory movement accuracy and focal length value stability, and improve the forming quality of the component.

[0053] The monitoring camera and the XYZ axis moving platform are connected to the robotic arm by bolts. The robotic arm is used to adjust the spatial pose of the monitoring camera and the XYZ axis moving platform during the manufacturing process.

[0054] The control device is connected to the monitoring camera, robotic arm, XYZ axis moving platform, electron beam power supply and wire feeder via 1553B bus. During the processing, it controls the monitoring camera to acquire image information of damage defects in real time and extract the location, contour shape and thickness features of damage defects. It controls the robotic arm and XYZ axis moving platform to adjust the pose of the electron beam welding gun in real time, and controls the electron beam power supply and wire feeder to adjust the electron beam current, electron beam spot position and wire feed speed in real time.

[0055] The monitoring camera and the XYZ axis moving platform are both installed at the end of the robotic arm.

[0056] This invention also proposes a manufacturing control method for electron beam filament repair of bent structural defects. The method classifies damaged defects based on their shape and size differences, and selects appropriate electron beam cutting, welding, or overlay welding processes for repair based on the specific defects. Figure 2 As shown, the repair process is as follows:

[0057] S1. Obtaining the contour information of the damaged area

[0058] Image information of damage and defects is acquired using a monitoring camera, and image processing algorithms are used to obtain feature data such as the location, contour shape, and thickness of the damage and defects.

[0059] S2. Classification of Damage and Defects

[0060] When repairing damage defects, the values ​​of various electron beam process parameters are determined based on parameters such as the material, thickness, and spatial location of the damage defect. For ease of description, it is stipulated that, under the same repair process parameters, the width of a single weld formed by the electron beam welding gun on a flat plate is B, and the thickness is T. Defects are classified according to their area and thickness:

[0061] (1) When the defect thickness t is less than or equal to the single weld thickness T, it is defined as a small thickness defect; when t is greater than T, it is defined as a large thickness defect.

[0062] (2) When the defect width b is less than or equal to the width B of a single weld pass, it is defined as a small-size defect. When the defect width b is in the range of B to 1.5B, it is defined as a medium-size defect. When b is greater than or equal to 1.5B, it is defined as a large-size defect.

[0063] S3. Determine the repair process based on the type of damage / defect.

[0064] (1) For defects with small thickness and small size (such as narrow slit defects), electron beam welding process is selected for repair based on the generated welding torch movement trajectory.

[0065] (2) For defects with small thickness and medium size, the electron beam welding process of the oscillating welding gun is selected for repair based on the zigzag oscillation path.

[0066] (3) For defects with small thickness and large size (such as hole defects), firstly, the electron beam cutting process is used to prepare repair parts that match the shape of the damaged defect. Then, the repair parts are welded to the defect position by the electron beam welding process for repair.

[0067] (4) For large thickness defects, based on the single-layer repair processes (1), (2), and (3) above, electron beam wire bonding process is selected to repair the defects in a multi-layer deposition manner. The repair process of each layer in the multi-layer deposition is the same as the repair process of large, medium, and small size defects with small thickness.

[0068] In step S3, the methods for generating and optimizing the welding torch motion trajectory corresponding to different types of damage defects are as follows:

[0069] (1) Small thickness and small size defects

[0070] ① Use the centerline skeleton extraction algorithm to obtain the centerline of the damage defect contour, identify and calculate the curvature radius values ​​at different positions of the centerline, and mark the positions of the numerical change points;

[0071] ② Because the defect contour is an irregular shape with a large number of numerical abrupt change points, the shape of the generated centerline is prone to be complex. To simplify the welding torch movement path, when the distance d between numerical abrupt change points is less than the width B of a single weld pass, the midpoint of the two points is used to replace the two points. As shown in Figure 3(a), when the distance d between points p3 and p5 is small, p4 is used to replace p3 and p5, and the trajectory changes from p2-p3-p5 to p2-p4.

[0072] ③ Following step ②, calculate and merge the remaining numerical mutation points until there is at most one point in each segment of length D of the centerline. Use this point as the endpoint to divide the centerline into segments, and connect the endpoints with straight lines to form a regular trajectory composed of straight lines. D is a constant value selected based on engineering experience, and the minimum value of D is greater than B. As shown in Figure 3(b).

[0073] (2) Small thickness, medium size defects

[0074] Based on the above-mentioned small-size defect repair process, the width of the formed weld is increased by adopting a broken-line oscillation path to achieve the repair of medium-size defects. As shown in Figure 3(a), the broken-line oscillation trajectory used between points p1 and p2 is illustrated. The oscillation amplitude can be set to 0.60–0.70 times the average defect width, and the oscillation length to 0.30–0.50 times the oscillation amplitude, with a shape as shown... Figure 4 As shown.

[0075] (3) Small thickness, large size defect

[0076] ① Identify and calculate the radius of curvature values ​​at different locations on the defect contour line, mark the locations of numerical abrupt change points, and to simplify the welding torch movement path, when the distance d between numerical abrupt change points is less than the width B of a single weld pass, use the midpoint of the two points instead of the two points. For example... Figure 5 As shown, when the distance between p2 and p4 is small, the midpoint p3 of the two points is used to replace p2 and p4, and the welding torch trajectory changes from p1-p2-p3-p4-p5 to p1-p3-p5.

[0077] ② Following step ①, calculate and merge the remaining numerical abrupt change points until at most one point exists within each segment of the contour line of length D (the minimum value of D should be greater than B). Use this point as the endpoint to segment the contour line, and connect the endpoints with straight lines to form a regular shape composed of straight lines. The trajectory generation method is as follows: Figure 6 As shown.

[0078] ③ Optimize the welding torch trajectory at the bending position of the forming path using a transition arc to ensure the smoothness and continuity of the welding torch movement during the repair process, avoid repeated start-up and termination of the arc and the welding torch lingering at the bending position, and improve the forming quality of the component. Typical optimization methods for bending angles are as follows: Figure 7 As shown, the minimum radius of curvature of the transition arc should be greater than 0.5B.

[0079] Repairing defects and damage of small thickness and large size:

[0080] ① Based on the welding torch movement trajectory generated above, the outline of the damage defect is trimmed using electron beam cutting technology to remove defects such as curling edges, so that the outline of the damage defect becomes a regular shape composed of straight lines.

[0081] ② Electron beam cutting is used to cut and obtain the repaired part based on a proportionally magnified welding torch motion trajectory. To ensure repair quality, the area of ​​the repaired part should be larger than the damage / defect contour. The distance between the repaired part contour and the damage / defect contour is approximately 0.5–2.0 mm. The magnification ratio of the welding torch motion trajectory corresponding to cutting the repaired part and repairing the damage / defect contour is approximately 1.01–1.1 times. Comparison of the repaired part and the damage / defect contour is shown in the figure. Figure 8 As shown.

[0082] ③ The defect is repaired by using electron beam welding technology and following the same welding torch movement trajectory as the part being cut and repaired.

[0083] The system of this invention uses a robotic arm for large-range coarse adjustment and an XYZ axis moving platform for small-range fine adjustment, enabling the coaxial wire feeding electron beam welding gun to accurately complete the defect repair according to the planned motion trajectory.

[0084] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0085] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A manufacturing control system for repairing bent structural defects using electron beam fuses, characterized in that, It includes an XYZ axis moving platform, a monitoring camera, a coaxial wire feeding electron beam welding gun, a wire feeder, a control device, an electron beam power supply, and a robotic arm; The wire feeder is screwed to the coaxial wire feeding electron beam welding gun, which feeds the welding wire along the central axis of the electron beam welding gun. The XYZ axis moving platform is screwed to the coaxial wire feeding electron beam welding gun. During the electron beam processing, the position of the welding gun is adjusted in real time according to the change of the defect position to ensure the accuracy of trajectory movement and the stability of focal length. The monitoring camera and the XYZ axis moving platform are connected to the robotic arm, which is used to adjust the spatial pose of the monitoring camera and the XYZ axis moving platform during the manufacturing process. The control device is connected to the monitoring camera, robotic arm, XYZ axis moving platform, electron beam power supply and wire feeder via 1553B bus. During the processing, it controls the monitoring camera to acquire image information of damage defects in real time and extract the location, contour shape and thickness features of damage defects. It controls the robotic arm and XYZ axis moving platform to adjust the pose of the electron beam welding gun in real time, and controls the electron beam power supply and wire feeder to adjust the electron beam current, electron beam spot position and wire feed speed in real time.

2. The manufacturing control system for repairing bent structural defects using electron beam fuses according to claim 1, characterized in that, The Z-axis of the XYZ axis moving platform is parallel to the central axis of the electron beam welding gun.

3. The manufacturing control system for repairing bent structural defects using electron beam fuses according to claim 1, characterized in that, The monitoring camera and the XYZ axis moving platform are both mounted at the end of the robotic arm.

4. A manufacturing control method for repairing electron beam fuse defects in bent structures based on the system described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. Use a monitoring camera to acquire image information of damage and defects, and use image processing algorithms to obtain the location, contour shape and thickness features of damage and defects; S2. Under the same repair process parameters, let the width of a single weld formed by an electron beam welding gun on a flat plate be B, and the thickness be T. Classify the defects according to the area and thickness of the defect damage: When the defect thickness t is less than or equal to the single weld thickness T, it is defined as a small thickness defect; when t is greater than T, it is defined as a large thickness defect. When the defect width b is less than or equal to the width B of a single weld, it is defined as a small defect; when the defect width b is in the range of B to 1.5B, it is defined as a medium defect; and when b is greater than or equal to 1.5B, it is defined as a large defect. S3. Determine the repair process based on the type of damage / defect: For defects with small thickness and small size, electron beam welding is selected for repair based on the generated welding torch motion trajectory. For defects with small thickness and medium size, an electron beam welding process using an oscillating welding gun is selected for repair based on a zigzag oscillation path. For defects with small thickness and large size, the first step is to use electron beam cutting technology to prepare repair parts that match the shape of the damaged defect. Then, the repair parts are welded to the defect location using electron beam welding technology for repair. For defects with large thickness, electron beam wire bonding is used to repair the defects in a multi-layer deposition manner. The repair process of each layer in the multi-layer deposition is the same as the repair process of large, medium and small size defects with small thickness.

5. The manufacturing control method for repairing bent structural defects with electron beam filament according to claim 4, characterized in that, The method for generating welding torch movement trajectories for small-thickness, small-size defects is as follows: ① Use the centerline skeleton extraction algorithm to obtain the centerline of the damage defect contour, identify and calculate the curvature radius values ​​at different positions of the centerline, and mark the positions of the numerical change points; ② When the distance d between numerical change points is less than the width B of a single weld, the midpoint of the two points is used instead of the two points; ③ Calculate and merge the remaining numerical mutation points according to step ② until there is at most one point in each segment of length D of the center line. Use this point as the endpoint to divide the center line into segments and connect the endpoints with straight lines to form a regular trajectory composed of straight lines. Here, D is a constant value selected based on engineering experience, and the minimum value of D is greater than B.

6. The manufacturing control method for repairing electron beam fuse defects in a bent structure according to claim 4, characterized in that, For small-thickness, medium-sized defects, the oscillation path is set to an oscillation amplitude of 0.6 to 0.7 times the average width of the defect, and an oscillation length of 0.3 to 0.5 times the oscillation amplitude.

7. The manufacturing control method for repairing electron beam fuse defects in a bent structure according to claim 4, characterized in that, The method for generating welding torch movement trajectories for small-thickness, large-size defects is as follows: ① Identify and calculate the radius of curvature values ​​at different positions of the damage defect contour line, mark the positions of the numerical change points, and when the distance d between the numerical change points is less than the width B of a single weld, use the midpoint of the two points to replace the two points. ② Following step ①, calculate and merge the remaining numerical mutation points until there is at most one point within the range of each segment length D of the contour line. Use this point as the endpoint to divide the contour line into segments, and connect the endpoints with straight lines to form a regular figure composed of straight lines; where the minimum value of the constant D is greater than B. ③ The welding torch movement trajectory at the bending position of the forming path is optimized by using a transition arc to ensure the smoothness and continuity of the welding torch movement during the repair process.

8. The manufacturing control method for repairing electron beam fuse defects in a bent structure according to claim 7, characterized in that, The minimum radius of curvature of the transition arc is greater than 0.5B.

9. The manufacturing control method for repairing bent structural defects with electron beam fuses according to claim 7, characterized in that, Repairing defects and damage of small thickness and large size: According to the generated welding torch movement trajectory, the damage defect contour is trimmed by electron beam cutting process to remove the curling defect and make the damage defect contour into a regular shape composed of straight lines. The repair parts are obtained by using electron beam cutting technology, based on the proportionally magnified motion trajectory of the welding torch. Electron beam welding is used to repair defects by following the same welding torch movement trajectory as the parts being cut and repaired.

10. The manufacturing control method for repairing electron beam fuse defects in a bent structure according to claim 9, characterized in that, The area of ​​the repaired part is larger than the outline of the damage defect. The distance between the outline of the repaired part and the outline of the damage defect is 0.5 to 2.0 mm. The magnification ratio of the welding torch movement trajectory corresponding to cutting the repaired part and trimming the outline of the damage defect is 1.01 to 1.1 times.

Images