Profile measuring method and auxiliary measuring tool

Abstract

The invention discloses a profile measuring method and an auxiliary measuring tool, and the method comprises the steps: setting a first mark point on a profile of a to-be-measured part; continuous second mark points are arranged on the same side of the two adjacent molded surfaces of the to-be-detected component, and the coverage range of the second mark points penetrates through the thickness direction of the two adjacent molded surfaces of the to-be-detected component; performing in-situ scanning on the to-be-measured component by using photogrammetric equipment based on the first mark point and the second mark point; using a laser scanner to scan and splice the molded surface features of the to-be-detected component based on the first mark point and the in-situ scanning data; stable space reference can be provided for the laser scanner to measure the upper profile and the lower profile of the wing, the problems of discontinuous mark points, scanning drifting and the like in traditional measurement are effectively solved, the measurement precision is guaranteed, and the feasibility of high-altitude operation is improved.

Description

Technical Field

[0001] This invention relates to the field of profile measurement technology, specifically to a profile measurement method and auxiliary measurement tool. Background Technology

[0002] During aircraft maintenance, data needs to be collected on the aircraft's theoretical shape in situ, typically using a handheld 3D scanner for point cloud acquisition. The airfoil is one of the most frequently scanned areas, and in-situ scanning is performed at high altitudes.

[0003] In practice, scaffolding or aerial work platforms are usually required for the operation. For example, CN114061486B discloses an automated measurement device and method for large aircraft skin surfaces. The automated measurement device includes a scanner, a robotic arm, a vision sensor, a control cabinet, a moving platform, and a dynamic tracking system. The moving platform is equipped with a lidar, the control cabinet is mounted on the moving platform, the vision sensor is mounted on the control cabinet, the robotic arm is fixed above the control cabinet, the scanner is mounted at the end of the robotic arm via a connecting fixture, the scanner has reflective dots on its external positioning ball, and the dynamic tracking system consists of a binocular camera used to capture the reflective dots on the scanner to obtain the spatial pose of the scanner in real time.

[0004] Existing solutions rely on fixed mobile platforms and visual tracking systems. Due to the excessive discontinuity of the wing surface markers and the lack of additional reference features in the air to assist in positioning, conventional scanning methods can only scan both sides of the wing surface twice and then stitch them together using fitting features of the wing surface edges. However, during long-distance scanning, laser scanners are prone to slight drift, resulting in coordinate system offsets in the scanning data of the upper and lower wing surfaces, affecting the overall measurement accuracy and making it difficult to adapt to high-altitude measurement environments. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a surface measurement method and auxiliary measurement tool to solve the technical problem in the prior art that laser scanners are prone to slight drift during long-distance scanning, resulting in inaccurate stitching of scan data.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for measuring a profile, comprising: Set a first marker point on the surface of the component to be tested; On the same side of two adjacent surfaces of the component under test, continuous second marker points are configured, and the coverage area of ​​the second marker points extends through the thickness direction of the two adjacent surfaces of the component under test. Using photogrammetry equipment, the component under test is scanned in situ based on the first and second marker points; Using a laser scanner, the surface features of the component under test are scanned and stitched together based on the first marker point and in-situ scanning data.

[0007] In some embodiments, continuous second marker points are configured on the same side of two adjacent surfaces of the component under test, specifically including: The distribution surface of the first marker points is unfolded according to the scanning range; An auxiliary measuring tool is installed at the center of the unfolded position, so that the target wall formed by the auxiliary measuring tool on the side opposite to the part to be measured penetrates the thickness direction of the two adjacent surfaces of the part to be measured. Several secondary markers are placed on the target wall.

[0008] In some embodiments, the distance between the auxiliary measuring tool and the corresponding edge of the part to be measured is 120mm-140mm, and the included angle between the target wall and the center plane of two adjacent surfaces of the part to be measured is 60°-120°.

[0009] In some embodiments, during the installation of the auxiliary measuring tool, when the length of the surface scanning range is less than or equal to 2m, one auxiliary measuring tool is selected; when the length of the surface scanning range is greater than 2m, multiple auxiliary measuring tools are used and connected in series.

[0010] In some embodiments, the size of the first marker point is smaller than the size of the second marker point, and the distance between adjacent second marker points does not exceed 1.5 times the distance between adjacent first marker points.

[0011] In some embodiments, setting a first marker point on the surface of the component to be tested specifically includes: Determine the scanning range of the component under test; Within the surface scanning range of the component to be tested, the first marker points are pasted at the set intervals; First marker points are added to the critical edge area of ​​the component to be measured and to the clamping position of the auxiliary measuring tool. The maximum spacing between the marker points is no greater than 1 / 5 of the single-frame field of view of the laser scanner.

[0012] In some embodiments, the critical edge region includes the edge location of the component under test and the end face contour location.

[0013] In some embodiments, after performing in-situ scanning of the component under test based on the first marker point and the second marker point using a photogrammetric device, the method further includes: Check for duplicate points in the point cloud and check for misalignment of the edges of the component under test.

[0014] Secondly, the present invention provides an auxiliary measurement tool for implementing the surface measurement method as described in any of the above claims. The auxiliary measurement tool includes: a fixed structure and a target wall. The fixed structure is configured to connect to the component to be measured. The target wall is configured to penetrate the thickness direction of two adjacent surfaces of the component to be measured and is rotatably connected to the fixed structure. A plurality of second marker points are provided on the side of the target wall corresponding to the component to be measured.

[0015] In some embodiments, the target wall includes: a connector and a plurality of connectors. The connector has a rotating end and a connecting end that are connected to each other. The rotating end is rotatably connected to the fixed structure. The connecting end is arranged to extend along the thickness direction of two adjacent surfaces of the component under test and penetrates the thickness direction of the two adjacent surfaces of the component under test. The plurality of connectors are arranged in parallel along the length direction of the connecting end and are connected to the connecting end. Each connector has a plurality of second marker points on the side corresponding to the component under test.

[0016] Compared with existing technologies, the surface measurement method and auxiliary measurement tool provided by this invention first uses photogrammetry equipment to perform in-situ scanning based on first and second marker points to establish a precise global coordinate system. Then, the auxiliary measurement tool uses a laser scanner to scan the aircraft wing surface and stitch together edge fitting features, combining the first marker points and the in-situ scan data. By setting the first marker point on the surface of the component under test and arranging the auxiliary measurement tool with continuous second marker points on the same side of adjacent surfaces, and setting the second marker points to a cross-surface distribution, the scan data of the two surfaces can be aligned to the global coordinate system through the same set of reference points, providing a stable spatial reference for the laser scanner to measure the upper and lower wing surfaces. This effectively solves the problems of discontinuous marker points and scan drift in traditional measurements, ensuring measurement accuracy and improving the feasibility of high-altitude operations. Compared with existing technologies, this solution does not rely on an external optical positioning system; high-precision measurements can be completed with only portable equipment, making it particularly suitable for in-situ measurement scenarios in confined spaces such as aircraft maintenance. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of an auxiliary measuring tool provided in an embodiment of the present invention when connected in series; Figure 2 This is a three-dimensional structural schematic diagram of an auxiliary measuring tool provided in another embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the auxiliary measuring tool provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the auxiliary measuring tools provided in this embodiment of the invention when connected in series; Figure 5 This is an exploded structural diagram of the auxiliary measuring tool provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the fixed structure of the auxiliary measuring tool provided in the embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Target wall; 11. Connector; 111. Rotating end; 1111. First rotating shaft; 112. Connecting end; 1121. End connector; 1122. Connecting rod; 12. Connector; 121. Hollow square tube; 2. Fixed structure; 21. Support arm; 211. Rotary shaft connection hole; 212. Weight reduction groove; 22. Square clamp; 221. C-shaped connector; 222. Second rotating shaft; 23. Fixing clamp; 3. Auxiliary fixing holes. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] To address the technical problem of inaccurate data stitching caused by slight drift in laser scanners during long-distance scanning, this invention provides a surface measurement method and auxiliary measurement tool. This method provides a stable spatial reference for laser scanners to measure the upper and lower surfaces of airfoils, effectively solving problems such as discontinuous marker points and scanning drift in traditional measurements. It ensures measurement accuracy and improves the feasibility of high-altitude operations.

[0021] It should be noted that the surface measurement method and auxiliary measurement tools described in this invention are used for, but not limited to, the surface measurement of aircraft wings. For ease of explanation, this invention will only use the application of the surface measurement method and auxiliary measurement tools to the surface measurement of aircraft wings as an example. The principles of the surface measurement method and auxiliary measurement tools applied to the measurement of other types of components such as propellers and fuselage skins are essentially the same as those applied to the surface measurement of aircraft wings, and will not be elaborated here.

[0022] In a first aspect, embodiments of this application provide a surface measurement method, including: S1. Setting up surface markers: Set up the first marker on the surface of the part to be tested.

[0023] S2. Layout of auxiliary marker points: On the same side of two adjacent surfaces of the part to be tested, continuous second marker points are configured. The coverage of the second marker points extends through the thickness direction of the two adjacent surfaces of the part to be tested.

[0024] S3. Spatial positioning: Using photogrammetry equipment, the part to be measured is scanned in situ based on the first and second marker points.

[0025] S4. Surface Scanning: Using a laser scanner, based on the first marker point and in-situ scanning data, the surface features of the part under test are scanned and stitched together.

[0026] This invention proposes a method for measuring airfoil profiles. This method involves setting a first marker point on the profile of the component to be measured and configuring consecutive second marker points on the same side of two adjacent profiles. The second marker points are distributed across the profiles, covering the thickness direction of the component to be measured. This allows the scanning data of the upper and lower profiles to be aligned to the global coordinate system through the same set of reference points. This solves the problem of accurately locating fluorescent marker points in traditional scanning methods and enables in-situ scanning of airfoil profiles at the nominal accuracy of the scanner.

[0027] During the operation, photogrammetry equipment is first used to perform an in-situ scan of the part under test based on the first and second marker points to obtain preliminary scan data. Subsequently, the auxiliary measuring tools are disassembled, and a laser scanner is used to further scan and stitch the surface features based on the first marker point and the in-situ coordinate system. This method not only improves scanning efficiency but also reduces measurement errors through multiple scans and stitching.

[0028] Preferably, in this solution, the laser scanner is a handheld scanner, which is convenient for operators to use flexibly on-site. The portability of the handheld laser scanner allows the measurement work to be carried out without site restrictions, and can be performed in various complex environments such as high altitudes, further improving the flexibility and applicability of the measurement. In addition, in order to further improve the accuracy and efficiency of the measurement, the part to be measured can be pre-treated before step S1, such as cleaning the surface and removing impurities, to ensure that the marker points can be accurately and firmly set on the surface.

[0029] Of course, in other possible embodiments, when this solution is applied to a relatively stable environment such as the ground, the laser scanner can also be mounted on a tripod or robotic arm to achieve a more stable scanning operation.

[0030] It should be noted that in this solution, the photogrammetric device can be a positioning camera integrated into a laser scanner, or it can be an external device, such as a separately set handheld camera, capable of capturing the positional information of the first and second marker points to achieve in-situ scanning of the airfoil surface. Since laser scanning generates a large amount of point cloud data, if both are activated simultaneously, the system needs to process positioning and scanning data concurrently, which may lead to delays or mistracking. Therefore, the laser module remains inactive during the spatial positioning step. When the photogrammetric device is a positioning camera integrated into a laser scanner, only the positioning camera of the laser scanner is activated to track the marker points during the spatial positioning step; the laser module remains inactive at this time. After positioning stabilizes, the laser scanning step begins, at which point the laser module of the laser scanner is activated, and the scanner emits laser lines or a dot matrix to collect geometric data of the object's surface. When the photogrammetric device is a separately set handheld camera, it has a larger focal length and a longer effective working distance compared to an integrated device, making it suitable for long-distance, large-area measurements. Meanwhile, using a camera alone offers greater portability and facilitates in-situ scanning. Operators need to hold the camera and take pictures of the markers on the part under test one by one. The captured image data is imported into a computer, and feature points are extracted and matched using professional image processing software to construct a three-dimensional model of the part under test, thereby achieving spatial positioning.

[0031] The first and second markers are preferably fluorescent markers, which are attached to the airfoil and the auxiliary measuring tool. Of course, in other possible embodiments, the choice of markers is not limited to this; reflective markers, magnetic markers, or other types of markers can also be used, as long as they meet the identification and positioning requirements of the photogrammetric equipment and the laser scanner.

[0032] To improve the accuracy of spatial positioning, in some possible embodiments, step S1 specifically includes: S12. Determine the scanning range of the component to be tested.

[0033] S13. Within the surface scanning range of the component to be tested, paste the first marker points at the set intervals.

[0034] S14. Add a first marker point to the critical edge area of ​​the component to be measured and to the clamping position of the auxiliary measuring tool. The maximum spacing of the marker points shall not be greater than 1 / 5 of the single-frame field of view of the laser scanner and shall correspond to the size of the tooling target wall.

[0035] The scanning range of the component under test is typically 4-6 meters, with key edge areas including the leading and trailing edges of the airfoil and the end face contour. By adding first marker points at the leading and trailing edges of the airfoil, the end face contour, and the clamping position of the auxiliary measuring tool, the scanning data of these key areas can be made more accurate. At the same time, adding marker points at the tooling clamping position can compensate for measurement errors introduced by minor clamping deformations.

[0036] In the process of measuring airfoil profiles, a continuous spatial reference datum is established. In some possible embodiments, a surface unfolding positioning method is used to locate the installation position of the auxiliary tool. In step S2, continuous second marker points are configured on the same side of two adjacent profiles of the component under test, specifically including: S21. Expand the distribution surface of the first marker point according to the scanning range.

[0037] S22. Install an auxiliary measuring tool at the center of the unfolded position, so that the target wall formed by the auxiliary measuring tool on the side opposite to the part to be measured penetrates the thickness direction of the two adjacent surfaces of the part to be measured.

[0038] S23. Several second marker points are configured on the target wall.

[0039] Further, step S21 specifically involves virtually unfolding the upper and lower surfaces of the wing in the measurement coordinate system, creating a continuous measurement reference surface in space. Specifically, based on the theoretical shape data of the wing or the initial scan point cloud, a surface parametric unfolding algorithm (such as corner mapping or minimum deformation unfolding) is used to convert the three-dimensional curvature of the upper and lower wing surfaces into an approximately two-dimensional unfolded plane, thereby determining the optimal installation position of the auxiliary measurement tool. Through unfolding positioning, the marker points on the auxiliary tool can be simultaneously associated with the upper and lower wing surfaces, avoiding the coordinate system offset problem caused by multiple scans in traditional methods. Simultaneously, the unfolded reference surface can guide the data registration of photogrammetry and laser scanning, reducing subsequent stitching errors.

[0040] To ensure accurate acquisition of the second marker points at the surface edge during scanning and to form a continuous scanning path, the density of these marker points at the surface edge should be appropriately increased when setting them up. This is to avoid data loss or increased errors due to edge effects. Furthermore, the placement of the marker points should consider the scanning field of view and the scanner's working range to ensure that each marker point is clearly captured during the scanning process. Therefore, in some possible embodiments, the distance between the auxiliary measuring tool and the edge of the corresponding part to be measured is designed to be between 120mm and 140mm, and the angle formed between the target wall and the center plane of the two adjacent surfaces of the part to be measured is 60°-120°. The angle between the target wall and the surface is preferably 75°. The size of the first marker point is smaller than that of the second marker point. The diameter of the first marker point is 6mm, and they are pasted at a spacing of 100-150mm. The pasting method meets the focusing parameters of the scanner camera (the spacing matches the camera's viewing angle; the larger the viewing angle, the more proportionally the pasting spacing needs to be enlarged). The diameter of the second marker point is 16mm, and it is pasted on the transition path of the auxiliary tool. The spacing between adjacent second marker points does not exceed 1.5 times the spacing between adjacent first marker points. To simplify the operation, they are generally pasted at a spacing of 150-220mm, and the pasting position needs to be as random as possible.

[0041] In some possible embodiments, one or more auxiliary measuring tools may be used, the number of which is calculated based on the area after the first marker point is unfolded. During the installation of the auxiliary measuring tools, when the length of the surface scanning range is less than or equal to 2m, one auxiliary measuring tool is selected; when the length of the surface scanning range is greater than 2m, multiple auxiliary measuring tools are used and connected in series. The multiple series-connected auxiliary measuring tools form a continuous array of marker points on the surface of the part to be measured, which not only expands the coverage of the measurement reference, but also enhances the stability of the spatial coordinate system.

[0042] In some possible embodiments, the in-situ scanning method in step S3 specifically includes: after installing the auxiliary tool, starting from the position of the auxiliary tool with the largest edge size, the marker points are collected. During operation, the positioning camera of the scanner is used to take pictures of the marker points for identification, and then the scanner moves along the shortest path to the nearest auxiliary tool position. This shooting process is repeated 3-5 times to ensure that all fluorescent marker points are stably identified without omission.

[0043] After establishing a global reference in the spatial positioning mode, to ensure the accuracy and stability of the spatial coordinate system, in some possible embodiments, after step S3, the following steps are further included: S31. Check for duplicate points in the point cloud and check for misalignment of the edges of the component under test. Checking for duplicate points specifically includes: examining the point cloud data in the scanning software to confirm there are no duplicate or redundant points (i.e., no multiple overlapping data points at the same location). In the scanning software, if the point cloud density in a certain area is abnormally high (e.g., local "ghosting" or dense noise), or if irregular protrusions / holes appear during mesh generation, it may indicate the presence of duplicate points. Checking for misalignment of the edges of the component under test specifically involves verifying the edge features of the object under test. By scanning the edge of the object from two directions, if the scanned meshes can be stitched together, the test is considered passed. Typically, the farthest 2-3 edges are selected for testing. If all tests pass, surface scanning can be initiated.

[0044] Calibration of positioning points: 1. Collect positioning points twice, only completing the spatial positioning step of positioning point collection. Manually perform coarse alignment of the two sets of points, set the search interval to 5-10mm, and use the ICP algorithm for further alignment to exclude unregistered points. Calculate the RMSD value and compare it with the scanner's nominal acquisition accuracy (different models of scanners have slight differences). If it does not exceed the nominal accuracy, the calibration is passed.

[0045] 2. With the measuring tools in the off-center position, place them at a maximum distance of 6m for testing. If the accuracy does not exceed the nominal accuracy, the calibration is passed.

[0046] Solutions for calibration failures (in-situ measurement status): 1. Check if the fluorescent markers on the auxiliary tool are contaminated with oil. Do not remove the contaminated points; simply replace the corresponding square tube in the auxiliary measuring tool.

[0047] 2. Check if the fluorescent markers on the edge of the object being tested are loose. If they are loose, first check for water dripping and oil contamination at the drain outlet, and re-attach or re-mark them.

[0048] 3. If the same points appear repeatedly, check if the scanning head lens is contaminated with dust or oil.

[0049] Please see Figures 1 to 4 Secondly, this application provides an auxiliary measurement tool for implementing the surface measurement method as described in any of the above embodiments. The auxiliary measurement tool includes a fixed structure 2 and a target wall 1. The fixed structure 2 is configured to connect to the component to be measured. The target wall 1 is configured to penetrate the thickness direction of two adjacent surfaces of the component to be measured and is rotatably connected to the fixed structure 2. A plurality of second marker points are provided on the side of the target wall 1 corresponding to the component to be measured.

[0050] During the airfoil profile measurement process, the target wall 1 can be fixed to the same side of both airfoil profiles using the fixed structure 2. This ensures that the second marker point on the target wall 1 accurately reflects the profile characteristics of the component under test during the scanning process. The side of the target wall 1 is rotatably connected to the fixed structure 2, allowing the target wall 1 to be adjusted in angle as needed to adapt to the measurement requirements of different airfoils.

[0051] To improve the stability of this auxiliary measurement tool's structure, please refer to... Figures 1 to 4 In some possible embodiments, fixing structures 2 are provided on both sides of the target wall 1, that is, when a set of auxiliary tools is used, such as Figure 2 and Figure 3 The tool includes a target wall 1 and two fixing structures 2 respectively located on both sides of the target wall 1. The two fixing structures 2 are symmetrically arranged and rotatably connected to the target wall 1. When using two sets of auxiliary tools, such as... Figure 2 and Figure 4 One set of auxiliary tools includes a target wall 1 and two fixing structures 2 respectively located on both sides of the target wall 1. The other set of auxiliary tools also includes a target wall 1 and a fixing structure 2 connected to one side of the target wall 1, while the other side of the target wall 1 is connected to the fixing structure 2 of the other set of auxiliary tools. The two sets of auxiliary tools are connected in series to form a continuous measurement reference, covering a larger scanning range.

[0052] Preferably, please refer to Figures 1 to 5 In this embodiment, the target wall 1 includes a connector 11 and multiple connecting members 12. The connector 11 has a rotating end 111 and a connecting end 112 connected to each other. The rotating end 111 is rotatably connected to the fixed structure 2. The connecting end 112 is arranged extending along the thickness direction of two adjacent surfaces of the component under test and penetrates the thickness direction of the two adjacent surfaces of the component under test. The multiple connecting members 12 are arranged side by side along the length direction of the connecting end 112 and are connected to the connecting end 112. The connecting end 112 extends along the thickness direction of two adjacent surfaces of the component under test and penetrates the thickness direction. The multiple connecting members 12 are arranged side by side along the length direction of the connecting end 112, ensuring the continuity and consistency of the second marker point on the upper and lower surfaces. Each connecting member 12 is provided with a second marker point, forming a continuous line of marker points. During the measurement process, the photogrammetric equipment and the laser scanner can perform precise spatial positioning and data stitching based on these continuous second marker points, thereby obtaining a complete three-dimensional model of the airfoil.

[0053] Furthermore, to further enhance the stability and applicability of auxiliary measurement tools, please refer to... Figures 1 to 5In one embodiment, the connector 12 includes a hollow square tube 121 made of lightweight material such as plastic, with a diameter of 10mm. The distance between two adjacent hollow square tubes 121 is 120mm. The arrangement of the parallel hollow square tubes 121 and the spacing between them facilitates the positioning of the second marker point, forming a continuous positioning base. Furthermore, the choice of lightweight material reduces the overall weight of the auxiliary measuring tool, allowing for flexible arrangement and adjustment by operators on-site. In addition, when applied in high-altitude environments, the target wall 1 formed by the hollow square tubes 121 reduces wind resistance and interference, providing better wind resistance and portability, and reducing measurement errors caused by wind. At the same time, it also has the safety protection function to prevent accidental falling from height and damaging equipment below or injuring people. Its structural design can reduce the impact force in the event of accidental detachment through the characteristics of lightweight materials and the distributed structure, thereby minimizing damage to ground personnel, facilities or precision instruments, and further reducing measurement errors and safety accidents caused by wind or operational mistakes.

[0054] Please see Figures 1 to 5 In another embodiment, the rotating end 111 of the connector 11 includes a first rotating shaft 1111, and the connecting end 112 includes a connecting rod 1122 and an end connector 1121. The first rotating shaft 1111 is rotatably connected to the fixed structure 2. One side of the connecting rod 1122 is fixedly connected to one end of the first rotating shaft 1111, and the other side is provided with an end connector 1121 along the length direction. The external dimensions of the end connector 1121 match the inner wall dimensions of the end of the hollow square tube 121, so that the end of the hollow square tube 121 can be stably inserted into the end connector 1121, thereby achieving a stable connection between the connector 12 and the connector 11. At the same time, the angle of the target wall 1 can be adjusted through the first rotating shaft 1111.

[0055] The design of fixed structure 2 takes into account the stability and convenience of measurement; please refer to [link / reference]. Figures 1 to 6In some possible embodiments, the fixing structure 2 includes a support arm 21, a square clamp 22, and a fixing clamp 23. The support arm 21 has pivot connection holes 211 at both ends and is designed with weight-reducing grooves 212, making it lightweight and mitigating the risk of falling. Even if damaged, it can be quickly repaired with adhesive. The square clamp 22 has two forms: single-joint and double-joint. The single-joint square clamp 22 includes a C-shaped connector 221 and a second pivot 222 connected thereto, used to connect a single target wall 1. The single-joint version includes a C-shaped connector 221 and two second pivots 222 connected thereto, used to connect target walls 1 in series. The second pivots 222 and the first pivot 1111 are respectively connected to the pivot connection holes 211 at both ends of the support arm 21. The fixing clamp 23 is connected to the C-shaped connector 221 to stably fix the square clamp 22 to the component under test. Specifically, the fixing clamp 23 is a finished part, which can be a 7-9 inch G-type clamp. Depending on the type of workpiece, a plastic clamp or a metal clamp can be selected to fix it to the workpiece. During high-altitude in-situ measurement, the thin plate edge is easy to clamp and is not easily affected by scaffold vibration.

[0056] The connector 12, support arm 21, square clamp 22, and fixing clamp 23 are all 3D printed using ABS (acrylonitrile-butadiene-styrene copolymer), nylon, or carbon fiber reinforced materials. The connections between the shaft and the hole, as well as between the hollow square tube 121 and the end connector 1121, are all plug-in joints with interference fit, relying on the elasticity of the plastic parts for fastening. Auxiliary fixing holes 3 are designed on the support arm 21 and square clamp 22; after the parts wear, they can be further secured using M3 nylon screws to extend their service life.

[0057] Of course, in other possible embodiments, the fixing structure 2 can also use suction cups or other methods to fix the position of the target wall 1. The specific forms of the connector 11 and the connecting member 12 are not limited to this, and can be flexibly designed according to actual needs, as long as they can meet the requirements of stable connection with the fixing structure 2 and continuous layout of the second marker point on the target wall 1. For example, the connector 11 can be a ball joint to achieve flexible rotation at multiple angles; the connecting member 12 can be rods of different lengths or perforated plates, etc.

[0058] This invention proposes a method and auxiliary measurement tool for wing profile measurement. The method first uses photogrammetry equipment to perform in-situ scanning based on first and second marker points to establish a precise global coordinate system. Then, the auxiliary measurement tool, using a laser scanner, combines the first marker points and the in-situ scan data to scan the aircraft wing profile and stitch together edge fitting features. By setting first marker points on the profile of the component under test and arranging the auxiliary measurement tool with continuous second marker points on the same side of adjacent profiles, and by using a cross-profile distribution of the second marker points, the scan data of the two profiles can be aligned to the global coordinate system through the same set of reference points. This provides a stable spatial reference for the laser scanner to measure the upper and lower wing profiles. This effectively solves the problems of discontinuous marker points and scan drift in traditional measurements, ensuring measurement accuracy and improving the feasibility of high-altitude operations. Compared to existing technologies, this solution does not rely on an external optical positioning system; high-precision measurements can be completed using only portable equipment, making it particularly suitable for in-situ measurement scenarios in confined spaces such as aircraft maintenance.

[0059] In the description of this application, it should be noted that the terms "upper" and "lower," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0060] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for measuring surface profiles, characterized in that, include: Set a first marker point on the surface of the component to be tested; On the same side of two adjacent surfaces of the component under test, continuous second marker points are configured, and the coverage area of ​​the second marker points extends through the thickness direction of the two adjacent surfaces of the component under test. Using photogrammetry equipment, the component under test is scanned in situ based on the first and second marker points; Using a laser scanner, the surface features of the component under test are scanned and stitched together based on the first marker point and in-situ scanning data.

2. The profile measurement method according to claim 1, characterized in that, The provision of consecutive second marker points on the same side of two adjacent surfaces of the component under test specifically includes: The distribution surface of the first marker points is unfolded according to the scanning range; An auxiliary measuring tool is installed at the center of the unfolded position, so that the target wall formed by the auxiliary measuring tool on the side opposite to the part to be measured penetrates the thickness direction of the two adjacent surfaces of the part to be measured. Several secondary markers are placed on the target wall.

3. The profile measurement method according to claim 2, characterized in that, The distance between the auxiliary measuring tool and the corresponding edge of the part to be measured is 120mm-140mm, and the included angle between the target wall and the center plane of the two adjacent surfaces of the part to be measured is 60°-120°.

4. The profile measurement method according to claim 1, characterized in that, During the installation of auxiliary measuring tools, when the length of the surface scanning range is less than or equal to 2m, one auxiliary measuring tool is selected; when the length of the surface scanning range is greater than 2m, multiple auxiliary measuring tools are used and connected in series.

5. The profile measurement method according to claim 1, characterized in that, The size of the first marker point is smaller than the size of the second marker point, and the distance between adjacent second marker points does not exceed 1.5 times the distance between adjacent first marker points.

6. The profile measurement method according to claim 1, characterized in that, Setting a first marker point on the surface of the component to be tested specifically includes: Determine the scanning range of the component under test; Within the surface scanning range of the component to be tested, the first marker points are pasted at the set intervals; First marker points are added to the critical edge area of ​​the component to be measured and to the clamping position of the auxiliary measuring tool. The maximum spacing between the marker points is no greater than 1 / 5 of the single-frame field of view of the laser scanner.

7. The profile measurement method according to claim 6, characterized in that, The critical edge region includes the edge position and end face contour position of the component under test.

8. The surface measurement method according to claim 1, characterized in that, After performing in-situ scanning of the component under test using photogrammetry equipment based on the first and second marker points, the method further includes: Check for duplicate points in the point cloud and check for misalignment of the edges of the component under test.

9. An auxiliary measuring tool, characterized in that, For implementing the profile measurement method as described in any one of claims 1-8, the auxiliary measurement tool includes: A fixed structure is configured to connect the component under test; and The target wall is positioned in the thickness direction of two adjacent surfaces of the component under test and is rotatably connected to the fixed structure. Several second marker points are provided on the side of the target wall corresponding to the component under test.

10. The auxiliary measuring tool according to claim 9, characterized in that, The target wall includes: A connector has a rotating end and a connecting end that are interconnected. The rotating end is rotatably connected to the fixed structure, and the connecting end is positioned to extend along the thickness direction of two adjacent surfaces of the component under test and penetrates the thickness direction of the two adjacent surfaces of the component under test. Multiple connectors are arranged in parallel along the length of the connecting end and connected to the connecting end. Each connector has several second marker points on the side corresponding to the component to be tested.

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