Special-shaped structure ultrasonic profiling scanning method and system based on lifting path calibration

Abstract

The invention discloses a special-shaped structure ultrasonic profiling scanning method and system based on lifting path calibration, which can intelligently identify the complex scanning surface of a workpiece and dynamically generate and adjust a scanning path, and adopts machine vision to guide a mechanical arm to clamp an ultrasonic probe to complete the nondestructive testing work of the special-shaped workpiece. The ultrasonic detection problem of various special-shaped workpieces is solved, the ultrasonic detection precision and efficiency of the special-shaped workpieces are improved, the ultrasonic probe is connected to the mechanical arm, it is guaranteed that the probe can accurately scan a detection point, meanwhile, accurate and controllable movement of the detection point is guaranteed, and the detection precision is improved. The applicability of detection of workpieces with complex shapes and the degree of freedom of a scanning path are enhanced; meanwhile, the detection efficiency of the workpiece can be greatly improved, the method is expected to be applied to field detection of the workpiece, and the problems that the workpiece with the special-shaped structure is difficult to detect, low in detection efficiency and large in error are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial automation ultrasonic detection, in particular to the technical field of a method and system for ultrasonic profiling of a water-immersed fully-focused special-shaped structure based on lifting path calibration. Background Art

[0002] In the field of industrial automation ultrasonic testing, the water immersion coupling method has excellent acoustic coupling ability, is less affected by clutter, is more applicable to workpieces of different shapes and sizes, and has the outstanding advantage of simple operation process, which makes this coupling method widely used in industrial testing. At present, the automated scanning technology commonly used for standard parts cannot adapt to the complex contours of non-standard parts autonomously, and still relies on CAD drawings and pre-set paths for the mechanical coordinate system. In theory, the above method can provide an effective detection path for standard parts, but in practical applications, the application of this method is limited by the geometric deviations and installation errors of non-standard parts.

[0003] These challenges mainly stem from two core issues: the installation error of the workpiece at the inspection station, and the complex scanning surface of the workpiece itself. Installation errors are usually caused by the unevenness of the supporting tooling or the matching error between the workpiece and the tooling, resulting in a deviation between the actual position of the workpiece and the expected position. In addition, the complex scanning surface of the workpiece, such as variable curves, irregular contours, and local features, further increases the complexity of inspection path planning. The preset path cannot flexibly adapt to the complexity of the actual workpiece and the slight changes during the installation process, which may lead to omissions or uneven coverage of key areas during the inspection process, thus affecting the accuracy and reliability of the inspection. In view of the above problems, there is an urgent need for an immersion ultrasonic inspection system that can adapt to the installation errors and complex scanning surfaces in the inspection of non-standard parts, so as to provide an efficient and accurate non-destructive inspection method for evaluating the internal quality of special-shaped workpieces. Summary of the invention

[0004] The purpose of the present invention is to solve the problems in the prior art and to propose an ultrasonic profiling scanning method and system for special-shaped structures based on lifting path calibration, which can intelligently identify the complex scanning surface of the workpiece and dynamically generate and adjust the scanning path to improve the accuracy and efficiency of ultrasonic detection of special-shaped workpieces.

[0005] To achieve the above-mentioned purpose, the present invention proposes an ultrasonic profiling scanning method for a special-shaped structure based on lifting path calibration, comprising a lifting device for carrying a workpiece and moving along a set path; a mechanical arm; an ultrasonic probe installed at the end of the mechanical arm; a water tank; and a structured light 3D camera; including: Step S1, setting a plurality of marking points on the lifting device, the marking points are installed within the field of view of the structured light 3D camera, and when there is no water in the water tank, the lifting device is raised to the highest point, and the spatial coordinates of the plurality of marking points at different heights are obtained by the structured light 3D camera, and the coordinate transformation at different positions is calculated, and the lifting path calibration formula related to the lifting stroke is obtained by fitting; Step S2, inject enough water into the water tank to fully immerse the workpiece, lift the workpiece above the water surface and obtain point cloud data of the workpiece's irregular surface through a structured light 3D camera, crop the collected point cloud data to determine the detection area, identify the data boundary, and plan the detection path and the end-of-arm posture control process according to the process parameter requirements of immersion fully focused ultrasonic testing; Step S3, controlling the lifting device to immerse the workpiece into the water tank, recording the descending distance, and updating the detection path and the robot end posture control process through the lifting path calibration formula; Step S4, issuing a detection task to the controller and the robot end posture solving module carried in the robot arm, and the robot end posture solving module sets the detection instrument synchronization parameters according to the path planning results. When the detection instrument completes the detection task, it transmits the detection data back in real time for subsequent processing; Step S5, repeating step S4 until the focus of the ultrasound probe traverses all designated locations in the path planning.

[0006] Preferably, in the step S1, four marking points are set on the lifting device, respectively located on four sides of the lifting device.

[0007] Preferably, the step S2 comprises: Step S2-1, point cloud preprocessing, denoising the original point cloud data, using a Gaussian filter to reduce the noise points generated during the scanning process; Step S2-2, point cloud clipping, use the octree data structure to perform spatial segmentation on the point cloud, quickly locate the detection area of ​​the workpiece, and clip the point cloud data: P′=Clip(P,AABB) where P′ is the clipped point cloud, P is the original point cloud, and AABB is the axis-aligned bounding box of the workpiece detection area; Step S2-3, workpiece feature recognition, using the classic region growing algorithm to segment the point cloud and identify the key feature parts of the workpiece. Starting from the seed point, the region is expanded according to the local geometric features of the point cloud until the preset similarity threshold is met; Step S2-4, detection area and boundary determination, according to the feature recognition results, determine the detection area of ​​the workpiece and calculate the boundary of the detection area.

[0008] Preferably, the step S2-3 comprises: Step S2-3.1, normal vector calculation and segmentation, first, calculate the normal vector of each point, use the principal component analysis method to estimate the normal vector of the point cloud, then cluster and segment the point cloud according to the similarity of the normal vectors, and classify points with similar normal vectors into the same category; Step S2-3.2, feature point extraction, based on the region growing segmentation results, extract feature points with high discrimination. These feature points will serve as key areas for subsequent detection and analysis to ensure accurate recognition of the workpiece surface morphology.

[0009] Preferably, the characteristic points include sharp edges, local protrusions or depressions.

[0010] Preferably, the boundary in step S2-4 is determined by a minimum circumscribed rectangle method, which generates a minimum rectangular enclosing area based on the coordinates of feature points on the workpiece surface to ensure that the path during the scanning process covers all target areas.

[0011] Preferably, in the step S1, the lifting platform is fully raised to the highest point, and a structured light 3D camera placed facing the workpiece is used to take pictures to obtain the spatial coordinates of the marking points at this time, the lifting device is controlled to descend, and pictures are taken with the structured light 3D camera at 1 / 4, 1 / 2, and 3 / 4 of the stroke respectively to obtain the spatial coordinates of the marking points at the corresponding positions.

[0012] Preferably, the step S1 includes: step S1-1, obtaining the spatial coordinates of the marker points, using a structured light 3D camera to shoot the marker point cluster, and at the highest point and target height Get the spatial coordinates of each marker point at At height The coordinates of , at height The coordinates of ; Step S1-2, calculate the centroid and align, calculate the centroid of the marker clusters at different heights, and obtain the corresponding translation vector: At height The centroid of : , At height The centroid of : ; Step S1-3, using the centroid difference Calculate the translation vector: ; Then align the coordinates of the marker points to the centroid reference system, that is, remove the translation part to obtain the centroid coordinates: ; ; Calculate the rotation difference and use the centroided marker coordinates to calculate the rotation matrix R; Constructing the covariance matrix : ; Through the covariance matrix Perform singular value decomposition to obtain an orthogonal matrix and : ; Calculate the rotation matrix : ; Step S1-5, fitting the lifting path calibration formula, at different heights Next, record the rotation matrix of the lifting platform and translation vector , and the linear formula can be used to fit the Function of change and ; ; ; Among them is The initial rotation matrix, is the initial translation vector, , is the fitting coefficient matrix; Step S1-6, applying translation and rotation to calibrate the surface point cloud coordinates of the workpiece in water immersion to obtain the surface scanning coordinates of the workpiece at the highest point Then, the fitted translation vector and the rotation matrix Applied to any target height, the calibrated The immersion scanning coordinates at position are .

[0013] Another object of the present invention is to provide an ultrasonic profiling scanning system for special-shaped structures based on lifting path calibration, comprising: A lifting device, used to carry the workpiece and move it along a set path; a robotic arm for controlling the movement of the ultrasound probe according to the planned path; An ultrasonic probe, used for transmitting and receiving ultrasonic signals, is installed at the end of the robotic arm; Ultrasonic imaging module, used for collecting and processing ultrasonic signals and generating high-resolution ultrasonic images; A control module, used to control the robot arm to perform scanning along the surface of the workpiece according to a pre-calibrated path, and to adjust the posture of the ultrasonic probe on the robot arm; A water tank is used to provide a liquid immersion environment to ensure that the workpiece is completely immersed in the liquid during ultrasonic scanning; The structured light 3D camera is used to obtain the point cloud information of the workpiece surface and calibrate the lifting path; the main control computer is connected with the structured light 3D camera, the robotic arm, and the ultrasonic probe; The data processing module is used to process the data collected from the structured light 3D camera and the fully focused ultrasonic imaging module, and perform scanning path planning and fully focused ultrasonic imaging.

[0014] Preferably, the lifting device comprises a vertically arranged lifting drive and a loading platform laterally arranged on the lifting drive.

[0015] Preferably, the robotic arm has more than six degrees of freedom.

[0016] The beneficial effects of the ultrasonic profiling scanning method and system for special-shaped structures based on lifting path calibration of the present invention are as follows: the present invention can intelligently identify the complex scanning surface of the workpiece and dynamically generate and adjust the scanning path, and adopts machine vision to guide the mechanical arm to clamp the ultrasonic probe to complete the non-destructive inspection of the special-shaped workpiece, thereby solving the ultrasonic inspection problem of various special-shaped workpieces and improving the accuracy and efficiency of ultrasonic inspection of special-shaped workpieces. By connecting the ultrasonic probe to the mechanical arm, it is ensured that the ultrasonic probe can accurately scan the inspection point while ensuring the precise and controllable movement of the inspection point, thereby enhancing the applicability of the inspection of workpieces with complex morphology and the degree of freedom of the scanning path; at the same time, it can greatly improve the inspection efficiency of the workpiece, and it is expected that the method can be applied to the on-site inspection of the workpiece, thereby solving the problems of the difficulty in detecting special-shaped structure workpieces, low inspection efficiency and large errors.

[0017] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the ultrasonic profiling scanning system for special-shaped structures based on lifting path calibration of the present invention.

[0019] In the figure: 1-robotic arm, 2-ultrasonic probe, 3-lifting drive, 4-structured light 3D camera, 5-stage, 6-workpiece, 7-water tank. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0021] In the description of the present invention, it should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0022] In the description of the present invention, it should be noted that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invention product is usually placed when in use, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Embodiment 1:

[0025] See also Figure 1The present invention discloses an ultrasonic profiling scanning system for a special-shaped structure based on the calibration of a lifting path, comprising a six-degree-of-freedom mechanical arm 1, a fully focused ultrasonic probe 2, a fully focused ultrasonic detector, a lifting device, a structured light 3D camera 4, a stage 5, a special-shaped workpiece to be inspected 6, a water tank 7, a main control computer, a fully focused ultrasonic detection instrument, and a mechanical arm control box; wherein the lifting device comprises a lifting drive 3 and a stage 5, the lifting drive 3 is used to drive the stage 5 to lift up and down, the fully focused ultrasonic probe 2 is installed at the end of the six-degree-of-freedom mechanical arm 1, and the fully focused ultrasonic probe 2 is coupled with the workpiece 6 through water. The structured light 3D camera 4 is fixed on the extension arm above the lifting drive 3, and the workpiece 6 is placed on the stage below the lifting drive 3. The main control computer is connected with the structured light 3D camera 4, the mechanical arm control box, and the fully focused ultrasonic detector. The main control computer has a built-in data processing module for processing the data collected from the structured light 3D camera and the fully focused ultrasonic imaging module, and performing scanning path planning and fully focused ultrasonic imaging. By connecting the fully focused ultrasonic probe to a six-degree-of-freedom robotic arm, it is ensured that the ultrasonic probe can accurately scan the detection point while ensuring the precise and controllable movement of the detection point, thereby enhancing the applicability of the detection of workpieces with complex morphologies and the freedom of the scanning path. At the same time, the use of this device can greatly improve the detection efficiency of workpieces, and it is expected that this method can be applied to on-site detection of workpieces, solving the problems of difficulty in detecting special-shaped structure workpieces, low detection efficiency, and large errors.

[0026] Embodiment 2:

[0027] See also Figure 1 On the basis of the first embodiment, the ultrasonic profiling scanning method of the special-shaped structure based on the lifting path calibration of the present invention comprises the following steps: step S1, coordinate system calibration, four marking points are set on the lifting device, and the four marking points are respectively set at the four corners of the stage 5, and the marking points are installed within the field of view of the structured light 3D camera 4. When there is no water in the water tank 7, the lifting device is raised to the highest point, and the spatial coordinates of multiple marking points at different heights are obtained by the structured light 3D camera, and the coordinate transformation at different positions is calculated, and the lifting path calibration formula related to the lifting stroke is obtained by fitting; specifically comprising: Step S1-1, obtain the spatial coordinates of the marker points, use a structured light 3D camera to shoot the marker point cluster, and and target height Get the spatial coordinates of each marker point at At height The coordinates of , at height The coordinates of ; Step S1-2, calculate the centroid and align, calculate the centroid of the marker clusters at different heights, and obtain the corresponding translation vector: At height The centroid of : ; At height The centroid of : ; Step S1-3, using the centroid difference Calculate the translation vector: ; Then align the coordinates of the marker points to the centroid reference system, that is, remove the translation part to obtain the centroid coordinates: ; ; Calculate the rotation difference and use the centroided marker coordinates to calculate the rotation matrix R; Constructing the covariance matrix : ; Through the covariance matrix Perform singular value decomposition to obtain an orthogonal matrix and : ; Calculate the rotation matrix : ; Step S1-5, fitting the lifting path calibration formula, at different heights For example, under 1 / 4, 1 / 2, and 3 / 4 strokes, record the rotation matrix of the lift table. and translation vectors , and the linear formula can be used to fit the Function of change and ; ; ; Among them is The initial rotation matrix, is the initial translation vector, , is the fitting coefficient matrix; Step S1-6, applying translation and rotation to calibrate the surface point cloud coordinates of the workpiece in water immersion, and in actual inspection, obtaining the surface scanning coordinates of the workpiece at the highest point After that, the fitted translation vector and the rotation matrix Applied to any target height, the calibrated The immersion scanning coordinates at position are .

[0028] Step S2, 3D data acquisition and processing, inject enough water into the water tank 7 so that the workpiece can be completely immersed, use the lifting drive 3 to drive the stage 5 to rise, lift the workpiece 6 above the water surface and obtain the point cloud data of the workpiece's irregular surface through the structured light 3D camera 4, and obtain the depth and position information of the workpiece. The resolution of cloud data acquisition is 0.05mm, which ensures high-precision capture of the workpiece surface features. Crop the collected point cloud data to determine the detection area and identify the data boundary. On this basis, plan the detection path and the end-of-arm posture control process according to the process parameter requirements of immersion fully focused ultrasonic testing; specifically including:

[0029] Step S2-1, point cloud preprocessing, denoising the original point cloud data, using a Gaussian filter to reduce the noise points generated during the scanning process; Step S2-2, point cloud clipping, using the octree data structure to spatially segment the point cloud, quickly locate the detection area of ​​the workpiece, and clip the point cloud data: P′=Clip(P,AABB) where P′ is the clipped point cloud, P is the original point cloud, and AABB is the axis-aligned bounding box of the workpiece detection area; Step S2-3, workpiece feature recognition, using the classic region growing algorithm to segment the point cloud, identify the key feature parts of the workpiece, and start from the seed point and expand the region according to the local geometric features of the point cloud until the preset similarity threshold is met;

[0030] Step S2-3.1, normal vector calculation and segmentation, first, calculate the normal vector of each point, use the PCA principal component analysis method to estimate the normal vector of the point cloud, then cluster and segment the point cloud according to the similarity of the normal vectors, and classify points with similar normal vectors into the same category;

[0031] Step S2-3.2, feature point extraction, based on the region growing segmentation results, extract feature points with high discrimination, such as sharp edges, local convex or concave areas, etc. These feature points will serve as key areas for subsequent detection and analysis to ensure accurate recognition of the workpiece surface morphology;

[0032] Step S2-4, detection area and boundary determination, according to the feature recognition results, determine the detection area of ​​the workpiece, and calculate the boundary of the detection area. The minimum circumscribed rectangle method is used to determine the boundary. This method generates a minimum rectangular enclosing area based on the coordinates of the feature points on the surface of the workpiece to ensure that the path in the scanning process covers all target areas. Step S3, path planning and posture control, control the lifting device to immerse the workpiece in the water tank 7, record the descending distance, and update the detection path and the end posture control process of the robot 1 through the lifting path calibration formula obtained in step S1-6;

[0033] Step S4, the main control computer issues a detection task to the controller and the robot terminal posture calculation module carried in the robot arm 1. The robot terminal posture calculation module sets the detection instrument synchronization parameters according to the path planning results, including the detection method, detection mode, detection accuracy, and trigger frequency, to ensure that the ultrasonic probe is always aligned with the normal line. When the detection instrument completes the detection task, it transmits the detection data back in real time for subsequent processing.

[0034] Step S5, repeating step S4 until the focus of the ultrasound probe traverses all designated locations in the path planning.

[0035] In summary, the present invention uses machine vision to guide a mechanical arm to clamp an ultrasonic probe to complete nondestructive testing of special-shaped workpieces, which specifically includes testing path planning, self-adaptation to the surface of the workpiece to be tested, high testing efficiency, etc.

[0036] It should be noted that, although the above embodiments have been described in this article, the scope of patent protection of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields are all included in the scope of protection of the patent of the present invention.

Claims

1. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration is characterized by: It includes a lifting device for carrying a workpiece and moving it along a set path; Robotic arm; Ultrasonic probe, installed at the end of the robotic arm; Water tank; Structured light 3D camera; The method comprises: step S1, setting a plurality of marking points on the lifting device, wherein the marking points are installed within the field of view of the structured light 3D camera, raising the lifting device to the highest point when there is no water in the water tank, obtaining the spatial coordinates of the plurality of marking points at different heights through the structured light 3D camera, calculating the coordinate transformation at different positions, and fitting to obtain a lifting path calibration formula related to the lifting stroke; Step S2, inject enough water into the water tank to fully immerse the workpiece, lift the workpiece above the water surface and obtain point cloud data of the workpiece's irregular surface through a structured light 3D camera, crop the collected point cloud data to determine the detection area, identify the data boundary, and plan the detection path and the end-of-arm posture control process according to the process parameter requirements of immersion fully focused ultrasonic testing; Step S3, controlling the lifting device to immerse the workpiece into the water tank, recording the descending distance, and updating the detection path and the robot end posture control process through the lifting path calibration formula; Step S4, issuing a detection task to the controller and the robot end posture solving module carried in the robot arm, and the robot end posture solving module sets the detection instrument synchronization parameters according to the path planning results. When the detection instrument completes the detection task, it transmits the detection data back in real time for subsequent processing; Step S5, repeating step S4 until the focus of the ultrasound probe traverses all designated locations in the path planning.

2. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration according to claim 1, characterized in that: In the step S1, four marking points are set on the lifting device, respectively located on four sides of the lifting device.

3. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration according to claim 1, characterized in that: The step S2 comprises: Step S2-1, point cloud preprocessing, denoising the original point cloud data, using a Gaussian filter to reduce the noise points generated during the scanning process; Step S2-2, point cloud clipping, use the octree data structure to perform spatial segmentation on the point cloud, quickly locate the detection area of ​​the workpiece, and clip the point cloud data: P′=Clip(P,AABB) where P′ is the clipped point cloud, P is the original point cloud, and AABB is the axis-aligned bounding box of the workpiece detection area; Step S2-3, workpiece feature recognition, using the classic region growing algorithm to segment the point cloud and identify the key feature parts of the workpiece. Starting from the seed point, the region is expanded according to the local geometric features of the point cloud until the preset similarity threshold is met; Step S2-4, detection area and boundary determination, according to the feature recognition results, determine the detection area of ​​the workpiece and calculate the boundary of the detection area.

4. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration according to claim 3, characterized in that: The step S2-3 comprises: Step S2-3.1, normal vector calculation and segmentation, first, calculate the normal vector of each point, use the principal component analysis method to estimate the normal vector of the point cloud, then cluster and segment the point cloud according to the similarity of the normal vectors, and classify points with similar normal vectors into the same category; Step S2-3.2, feature point extraction, based on the region growing segmentation results, extract feature points with high discrimination. These feature points will serve as key areas for subsequent detection and analysis to ensure accurate recognition of the workpiece surface morphology.

5. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration according to claim 4, characterized in that: The feature points include sharp edges, local protrusions or depressions.

6. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration according to claim 3, characterized in that: The boundary in step S2-4 is determined by using the minimum circumscribed rectangle method, which generates a minimum rectangular enclosing area based on the coordinates of the feature points on the surface of the workpiece to ensure that the path during the scanning process covers all target areas.

7. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration according to claim 1, characterized in that: In step S1, the lifting platform is fully raised to the highest point, and a structured light 3D camera placed facing the workpiece is used to take pictures to obtain the spatial coordinates of the marking points at this time, the lifting device is controlled to descend, and the structured light 3D camera is used to take pictures at 1 / 4, 1 / 2, and 3 / 4 of the stroke respectively to obtain the spatial coordinates of the marking points at the corresponding positions.

8. The ultrasonic profiling scanning method for special-shaped structures based on lifting path calibration according to claim 1, characterized in that: The step S1 comprises: Step S1-1, obtain the spatial coordinates of the marker points, use a structured light 3D camera to shoot the marker point cluster, and and target height Get the spatial coordinates of each marker point at At height The coordinates of , at height The coordinates of ; Step S1-2, calculate the centroid and align, calculate the centroid of the marker clusters at different heights, and obtain the corresponding translation vector: At height The centroid of : , At height The centroid of : ; Step S1-3, using the centroid difference Calculate the translation vector: ； Then align the coordinates of the marker points to the centroid reference system, that is, remove the translation part to obtain the centroid coordinates: ； ； Step S1-4, calculating the rotation difference, and using the centroided marker point coordinates to calculate the rotation matrix R; Constructing the covariance matrix : ； Through the covariance matrix Perform singular value decomposition to obtain an orthogonal matrix and : ； Calculate the rotation matrix : ； Step S1-5, fitting the lifting path calibration formula, at different heights Next, record the rotation matrix of the lifting platform and translation vector , and the linear formula can be used to fit the Function of change and ; ； ； Among them is The initial rotation matrix, is the initial translation vector, , is the fitting coefficient matrix; Step S1-6, applying translation and rotation to calibrate the surface point cloud coordinates of the workpiece in water immersion to obtain the surface scanning coordinates of the workpiece at the highest point Then, the fitted translation vector and the rotation matrix Applicable to any target height So we can get the calibrated The immersion scan coordinates at position are: .

9. An ultrasonic profiling scanning system for special-shaped structures based on lifting path calibration for implementing the method described in any one of claims 1 to 8, characterized in that: include: A lifting device, used to carry the workpiece and move it along a set path; a robotic arm for controlling the movement of the ultrasound probe according to the planned path; The ultrasonic probe is used to transmit and receive ultrasonic signals and is installed at the end of the robotic arm; the ultrasonic imaging module is used to collect and process ultrasonic signals and generate high-resolution ultrasonic images; A control module, used to control the robot arm to perform scanning along the surface of the workpiece according to a pre-calibrated path, and to adjust the posture of the ultrasonic probe on the robot arm; A water tank is used to provide a liquid immersion environment to ensure that the workpiece is completely immersed in the liquid during ultrasonic scanning; Structured light 3D camera, used to obtain point cloud information on the workpiece surface and calibrate the lifting path; A main control computer connected to the structured light 3D camera, the robotic arm, and the ultrasonic probe; The data processing module is used to process the data collected from the structured light 3D camera and the fully focused ultrasonic imaging module, and perform scanning path planning and fully focused ultrasonic imaging.

10. The ultrasonic profiling scanning system for special-shaped structures based on lifting path calibration according to claim 9, characterized in that: The lowering device comprises a vertically arranged lifting drive and a loading platform laterally arranged on the lifting drive.

Images