CN-122015646-A - Three-coordinate measuring and positioning system and method for repair welding of drawing type friction plugs

CN122015646ACN 122015646 ACN122015646 ACN 122015646ACN-122015646-A

Abstract

The invention provides a three-coordinate measuring and positioning system and method for repair welding of a drawing type friction plug, comprising the following steps: S1, operating a robot to drive a contact type measuring head to scan along a storage tank X, Y, Z shaft in a multipath manner, collecting three-dimensional coordinate data, and generating an initial three-dimensional contour point cloud. S2, preprocessing the initial point cloud, and performing measuring head radius offset compensation and temperature drift compensation to obtain corrected point cloud data. S3, reconstructing the curved surface by using a non-uniform rational B-spline algorithm, generating a high-precision three-dimensional model of the storage tank, and determining the defect center position and the normal vector. S4, transmitting relevant data to a robot control system through bus communication, and generating an obstacle avoidance movement path by combining laser ranging data. S5, adjusting the gesture of the robot to align the tool with the defect, monitoring through a visual sensor, triggering dynamic secondary compensation and updating a path when the deviation exceeds a threshold value, and ensuring accurate repair welding.

Inventors

ZHAO HUAXIA
ZHANG GENG
ZHAO YANHUA
CUI LEI
DONG JIHONG

Assignees

中国航空制造技术研究院

Dates

Publication Date: 20260512
Application Date: 20260209

Claims (8)

1. A three-coordinate measuring and positioning system for repair welding of a drawing type friction plug is characterized by comprising the following components: the robot comprises a robot body, wherein a main shaft knife handle is arranged at the tail end of the robot body; The three-coordinate measuring sensor is arranged on the spindle knife handle through a clamping and switching device and is used for contacting the surface of the storage box and collecting coordinates of measuring points; The control subsystem is used for latching grating signals of the measuring sensor, recording three-dimensional coordinates of the measuring points and generating point cloud data; The data processing module is used for carrying out surface fitting on the point cloud data, reconstructing a storage box curved surface model, and calculating the center position and the normal direction of the defect; and the robot controller is used for adjusting the gesture of the robot according to the central position and the normal direction of the defect so as to enable the zero point of the tool to coincide with the center of the defect and the tool to coincide with the normal direction.
2. The three-coordinate measuring and positioning system for repair welding of drawn friction plugs according to claim 1, wherein the clamping adapter device comprises: the tool handle connecting part is detachably connected with the main shaft tool handle; And the measuring head mounting part is used for fixing the three-coordinate measuring sensor, and a radius compensation adjusting structure is arranged between the measuring head mounting part and the cutter handle connecting part and used for compensating the influence of the measuring head radius on the measuring precision.
3. A three-coordinate measuring and positioning method for repair welding of a drawn friction plug, which is applied to the three-coordinate measuring and positioning system for repair welding of a drawn friction plug according to any one of claims 1 to 2, and is characterized by comprising the following steps: S1, operating a robot to drive a contact type measuring head to perform multipath scanning along the X, Y, Z axis direction of a storage box, collecting three-dimensional coordinate data of a measuring point, and generating an initial three-dimensional contour point cloud; s2, preprocessing the initial three-dimensional contour point cloud, including contact point offset compensation based on the radius of a measuring head and temperature drift compensation based on the linear expansion coefficient of a material, so as to obtain corrected point cloud data; s3, carrying out curved surface reconstruction on the corrected point cloud data by utilizing a non-uniform rational B spline algorithm, generating a high-precision three-dimensional model of the storage box exterior curved surface, and determining the center position and the normal vector of the defect based on the model; s4, transmitting the center coordinates and normal vectors of the defects to a robot control system through bus communication, and generating an obstacle avoidance motion path of the robot by combining defect edge data synchronously scanned by a laser ranging sensor; S5, adjusting the gesture of the robot to enable the tool zero point to coincide with the defect center and the tool axis to be aligned with the normal vector, monitoring the alignment state of the tool and the defect in real time through a vision sensor, and triggering dynamic secondary compensation to update the motion path of the robot if the deviation exceeds a preset threshold value.
4. The three-coordinate measuring and positioning method for repair welding of drawn friction plugs according to claim 3, wherein the preprocessing in step S2 further comprises: Noise filtering is carried out on the initial point cloud data by adopting a Kalman filtering algorithm; And dynamically adjusting the linear expansion coefficient according to the real-time temperature data of the storage tank material, and calculating the temperature drift compensation quantity.
5. The three-coordinate measuring and positioning method for repair welding of drawn friction plugs according to claim 3, wherein the generating of the robot obstacle avoidance motion path in step S4 comprises: planning a robot joint movement track based on an A-algorithm, and avoiding internal structural barriers of a storage tank; Introducing a path curvature constraint condition to ensure that the deviation between the tool motion process and the normal direction of the defect is less than 0.1mm; and transmitting the path parameters to the robot controller in real time through bus communication, and monitoring the risk of overrun of the joint angle.
6. A method of three-coordinate measuring and positioning for repair welding of drawn friction plugs according to claim 3, wherein the dynamic secondary compensation in step S5 comprises: Acquiring real-time relative position data of the cutter and the defect through a visual sensor, and calculating a deviation matrix; Matching the actual point cloud with a theoretical model by adopting an iterative nearest point algorithm, and generating a compensated robot target pose; after updating the motion path, steps S1 to S3 are re-executed until the alignment deviation meets the preset accuracy requirement.
7. The three-coordinate measuring and positioning method for repair welding of drawn friction plugs according to claim 3, wherein the specific steps of the NURBS curved surface reconstruction in the step S3 are as follows: extracting characteristic control points of the corrected point cloud data, and giving weight coefficients to the control points; according to the defect geometric shape, node vector distribution is adaptively adjusted, and the smoothness of the curved surface is optimized; and fitting the NURBS curved surface equation by a least square method, and outputting the defect center coordinates and normal vectors.
8. The three-coordinate measuring and positioning method for repair welding of drawn friction plugs according to claim 3, further comprising step S6: After repair welding is completed, performing three-dimensional shape detection on the repair area through a laser scanner, and generating a quality evaluation report; If the residual gap or the deformation is detected to be out of tolerance, the defect position is marked and the reworking flow is triggered.

Description

Three-coordinate measuring and positioning system and method for repair welding of drawing type friction plugs Technical Field The invention relates to the technical field of automatic measurement and welding, in particular to a three-coordinate measurement positioning system and method for repair welding of a drawing type friction plug. Background In various fields of aerospace, energy sources and the like, the manufacture and maintenance of large-scale equipment such as aerospace storage tanks, high-pressure containers and the like are very important. During long-term use, various defects, particularly typical defects such as round hole shape, can be inevitably generated on the surface of the equipment, and the safety and the reliability of the equipment are seriously affected. Taking a space storage tank as a key component of a spacecraft, the space storage tank needs to bear huge pressure in a space complex environment, and serious consequences can be caused by tiny surface defects. The traditional defect measurement method has lower precision, and is difficult to meet the severe requirements of high-end fields such as aerospace and the like on equipment manufacturing and maintenance. In the prior art, some methods can only obtain rough information of the surface, and cannot accurately measure critical parameters such as size, position and shape errors of defects. In addition, the measuring process is easy to be interfered by environmental factors, for example, the temperature change can cause the thermal expansion and the cold contraction of equipment materials, so that the deviation of a measuring result occurs, and the error of a measuring sensor can further reduce the measuring precision. In addition, when processing and analyzing the measured data, due to the limitations of algorithms and models, it is difficult to reconstruct the curved surface model of the device accurately, so that a reliable basis cannot be provided for subsequent repair work. In repair operation, the positioning and posture adjustment of the robot lack of accurate guidance, so that repair welding positions and angles are inaccurate, repair welding quality is affected, and the performance of equipment is difficult to recover to an ideal state. Therefore, the development of a three-coordinate measuring and positioning system and a method for the repair welding of the drawing type friction plug with high precision and high anti-interference capability is urgent. Disclosure of Invention The application provides a three-coordinate measuring and positioning system and method for repair welding of a drawing type friction plug, which are used for solving the problems in the background technology. In a first aspect, the present invention provides a three-coordinate measuring and positioning system for repair welding of a drawn friction plug, comprising: the robot comprises a robot body, wherein a main shaft knife handle is arranged at the tail end of the robot body; The three-coordinate measuring sensor is arranged on the spindle knife handle through a clamping and switching device and is used for contacting the surface of the storage box and collecting coordinates of measuring points; The control subsystem is used for latching grating signals of the measuring sensor, recording three-dimensional coordinates of the measuring points and generating point cloud data; The data processing module is used for carrying out surface fitting on the point cloud data, reconstructing a storage box curved surface model, and calculating the center position and the normal direction of the defect; and the robot controller is used for adjusting the gesture of the robot according to the central position and the normal direction of the defect so as to enable the zero point of the tool to coincide with the center of the defect and the tool to coincide with the normal direction. Further, the clamping adapter device comprises: the tool handle connecting part is detachably connected with the main shaft tool handle; And the measuring head mounting part is used for fixing the three-coordinate measuring sensor, and a radius compensation adjusting structure is arranged between the measuring head mounting part and the cutter handle connecting part and used for compensating the influence of the measuring head radius on the measuring precision. In a second aspect, the present invention provides a three-coordinate measuring and positioning method for repair welding of a drawn friction plug, which is applied to the three-coordinate measuring and positioning system for repair welding of a drawn friction plug as described above, and includes the following steps: S1, operating a robot to drive a contact type measuring head to perform multipath scanning along the X, Y, Z axis direction of a storage box, collecting three-dimensional coordinate data of a measuring point, and generating an initial three-dimensional contour point cloud; s2, preprocessing the initial three-dimen