A method for quickly supplementing horizontal measurement points on a radome

Abstract

The application discloses a kind of fast supplementing methods of horizontal measuring point on radome, belong to the technical field of aviation manufacturing assembly, first, prefabricated radome standard parts;In the stage of close fine processing, install radome standard parts, and mark out horizontal measuring point and local positioning reference point, establish local coordinate system;Then, remove radome standard parts;After formal radome installation, with the local positioning reference point marked on the adjacent fuselage skin of radome as reference, accurately supplement the horizontal measuring point on radome.The application effectively reduces the influence of structural deformation caused by fuselage structure stress release on the supplementing accuracy of horizontal measuring point, effectively improves work efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of aerospace manufacturing and assembly, specifically relating to a rapid replacement method for horizontal measurement points on an antenna radome. Background Technology

[0002] In the assembly process of large aircraft structures, the fuselage is typically divided into several large components, each assembled independently. These components are then joined together using a specialized jig to form the complete aircraft. This process of joining the large components to form the complete aircraft is generally referred to as the assembly and finishing stage of aircraft assembly. This stage uses a specialized jig for positioning, ensuring precise alignment between the physical coordinate system of the fuselage structure and the theoretical coordinate system of the aircraft. Therefore, the marking of horizontal measurement points on the fuselage is also performed during the assembly and finishing stage. This ensures the accuracy of the horizontal measurement point markings, which directly determine the accuracy of fuselage attitude adjustments and can also be used to monitor structural deformation of the fuselage throughout its subsequent lifecycle.

[0003] Specifically, the aircraft's radome consists of two parts, left and right, symmetrically installed on both sides of the fuselage. Each part has a horizontal measurement point, which serves as a crucial reference for adjusting the aircraft's horizontal attitude, determining its axis of symmetry and playing a vital role in the overall aircraft attitude. However, due to assembly process limitations or missing parts, most radome assembly is carried out after the final machining stage. Therefore, the horizontal measurement points need to be quickly and accurately fabricated after the radome installation is complete. During radome installation, the fuselage is freed from the constraints of the specialized jig, resulting in significant stress release and changes in the fuselage structure's position. Consequently, the positions of the corresponding horizontal measurement points also change.

[0004] The current method for fabricating horizontal measurement points uses the fuselage horizontal measurement points marked during the final assembly stage as a reference to establish an aircraft coordinate system, and then fabricates the horizontal measurement points on the radome within this coordinate system. However, due to structural deformation caused by the release of stress in the fuselage structure, the established aircraft coordinate system has significant deviations. Ultimately, all deviations will accumulate on the horizontal measurement points on the radome. According to a large amount of data analysis, the current method results in significant positional deviations of the horizontal measurement points, and the marked horizontal measurement points on the radome pose a considerable risk of exceeding assembly process specifications. Summary of the Invention

[0005] The purpose of this invention is to provide a method for rapidly supplementing horizontal measurement points on an antenna radome, thereby solving the aforementioned problems.

[0006] This invention is mainly achieved through the following technical solutions:

[0007] A method for rapidly supplementing horizontal measurement points on an antenna radome includes the following steps:

[0008] Step S1: Pre-fabricate standard antenna radome parts;

[0009] Step S2: During the assembly and finishing stage, install the standard radome component, mark the horizontal measurement points and local positioning reference points, and establish a local coordinate system; then, remove the standard radome component.

[0010] Step S3: After the formal radome is installed, use the local positioning reference points marked on the adjacent fuselage skin of the radome as a reference to accurately make up the horizontal measurement points on the radome.

[0011] To better realize the present invention, step S2 further includes the following steps:

[0012] Step S21: During the assembly and finishing stage, pre-install the standard radome component and mark the horizontal measurement points on the standard radome component; at this time, the physical coordinate system of the fuselage structure is consistent with the theoretical coordinate system of the aircraft.

[0013] Step S22: Mark local positioning reference points on the fuselage skin adjacent to the radome;

[0014] Step S23: Under the current laser tracker coordinate system, measure the horizontal measurement point HS and the local positioning reference point BS, and establish the local coordinate system CS.

[0015] To better realize the present invention, in step S21, a dotting tool is used to mark horizontal measurement points on the standard part of the radome; in step S22, a crosshair dotting stamp is used to mark local positioning reference points on the adjacent fuselage skin of the radome.

[0016] To better realize the present invention, in step S22, the local positioning reference points are evenly distributed on the fuselage skin adjacent to the radome, and the number of distribution points is ≥7.

[0017] To better realize the present invention, step S3 further includes the following steps:

[0018] Step S31: When the formal radome is installed, the formal radome is positioned and installed on the fuselage, and the fuselage is freed from the constraints of the jig tooling, and reaches a stable stage after stress release.

[0019] Step S32: Under the current laser tracker coordinate system, obtain the local positioning reference point BO that is currently measured. Using the local positioning reference point BS in step S23 as the reference, calculate the rotation and translation matrix {R,T} between the local positioning reference point BO and the local positioning reference point BS through the iterative nearest neighbor algorithm, and transform the current laser tracker coordinate system to the local coordinate system CS constructed in step S23.

[0020] Step S33: In the local coordinate system, the measurement points are sequentially pointed to the horizontal measurement points measured in step S23 and accurately marked, thereby achieving accurate marking of the horizontal measurement points on the radome.

[0021] To better implement this invention, further, in step S32, the iterative nearest neighbor algorithm finds a rotation and translation transformation matrix {R,T} through iterative optimization, such that the point distance error between corresponding point pairs of local positioning reference point BO and local positioning reference point BS is minimized. Its optimization objective is:

[0022]

[0023] Where: N is the total number of local positioning reference points;

[0024] R is the rotation matrix;

[0025] T is the translation matrix.

[0026] The beneficial effects of this invention are as follows:

[0027] (1) This invention pre-fabricates standard radome parts, installs these standard parts during the assembly and finishing stage, and marks horizontal measurement points on the radome standard parts and local positioning reference points on the adjacent fuselage skin areas of the radome. A local coordinate system is constructed using the marked horizontal measurement points and local positioning reference points. Then, after the formal radome is installed, the horizontal measurement points on the radome are precisely fabricated using the marked local positioning reference points on the adjacent fuselage skin as a reference. This reduces the positional error of the horizontal measurement points caused by structural deformation due to stress release of the entire fuselage. Statistically, the positional error of the horizontal measurement points can be reduced by approximately 7 times. This invention simplifies the process of constructing the reference coordinate system in horizontal measurement fabrication, reducing the entire process time for horizontal measurement point fabrication of the radome from three hours to within one hour, significantly improving work efficiency.

[0028] (2) This invention utilizes pre-assembled standard radome parts, marking horizontal measurement points and local positioning reference points, and constructing a local coordinate system as the reference coordinate system. Then, after the final radome installation, the horizontal measurement points on the radome are fabricated. This method effectively reduces the impact of structural deformation caused by stress release on the accuracy of horizontal measurement point fabrication. This invention can be applied to the fabrication of horizontal measurement points or other feature points on the surfaces of other parts of the fuselage. While ensuring the accuracy and efficiency of horizontal measurement point or other feature point fabrication, it can effectively control the progress of fuselage assembly production tasks and the scope of process operations. Attached Figure Description

[0029] Figure 1 This is a flowchart of the rapid replacement method for horizontal measurement points on the radome of the present invention;

[0030] Figure 2 This is a structural diagram of the current dotting tool;

[0031] Figure 3 This is a schematic diagram of the structure of an extremely fine crosshair dot stamp;

[0032] Figure 4 This is a schematic diagram showing the spatial layout of local positioning reference points;

[0033] Figure 5 This is a schematic diagram of the laser tracker and the T-Probe handheld probe.

[0034] The components include: 1. Marking fixture, 2. Antenna radome standard parts, 3. Horizontal measuring points, 4. Local positioning reference points, 5. Laser tracker, and 6. T-Probe handheld probe. Detailed Implementation

[0035] Example 1:

[0036] A rapid method for reconstructing horizontal measurement points on an antenna radome, such as... Figure 1 As shown, it includes the following steps:

[0037] 1: According to the requirements for radome processing and manufacturing, standard radome part 2 is processed and manufactured. Only one standard radome part 2 is needed to meet the need for replacement of horizontal measurement points 3 on all batches of radomes of the same model.

[0038] 2: During the final assembly stage, install standard part 2 of the radome. At this point, the physical coordinate system of the fuselage structure is consistent with the theoretical coordinate system of the aircraft, such as... Figure 2 and Figure 4 As shown, the horizontal measurement point 3 is marked on the standard part 2 of the radome using the dotting tool 1.

[0039] 3: For example Figure 3 and Figure 4 As shown, an extremely fine "+" shaped dot stamp is designed. Using this stamp, local positioning reference points 4 are marked on the adjacent fuselage skin of the radome, serving as local reference points for horizontal point supplementation on the radome. These local positioning reference points 4 need to be evenly distributed on the adjacent fuselage skin of the radome. The spatial position of the local reference points only needs to be evenly distributed on the adjacent fuselage skin of the radome. This spatial position does not require strict positioning control, but to ensure the accuracy of horizontal measurement point 3 supplementation, the number of points must be greater than or equal to 7.

[0040] 4: For example Figure 5As shown, using a laser tracker 5 and its accessory T-Probe handheld probe 6, the horizontal measurement point 3 marked in step 2, HS = {HS1, HS2}, and all the local positioning reference points 4 set in step 3, BS = {BS1, BS2, ..., BS2}, are quickly measured in the coordinate system of the laser tracker 5. N}(N≥7), and establish a local coordinate system CS.

[0041] 5: Remove standard part 2 of the radome. When the process reaches the formal radome installation, position and install the formal radome parts on the fuselage according to the process requirements. At this time, the fuselage is freed from the constraints of the special frame tooling and has reached the stable stage after stress release.

[0042] 6: Still using the laser tracker 5 and its accessory T-Probe handheld probe 6, in the current coordinate system CO of the laser tracker 5, measure all the local positioning reference points 4 set up in step 3 as BO = {BO1, BO2, ..., BO}. N}(N≥7), using all the local positioning reference points BS measured in step 4 as references, the rotation and translation matrix {R,T} between the currently measured local positioning reference point BO and the local positioning reference point BS measured in step 4 is calculated by the iterative nearest neighbor algorithm, and the current coordinate system of laser tracker 5 is transformed to the local coordinate system CS constructed in step 4.

[0043] 61: The core of the Iterative Nearest Neighbor Algorithm is to iteratively optimize and find a rotation and translation transformation matrix {R,T} that minimizes the point distance error between corresponding point pairs of local positioning reference points BO and BS. Its optimization objective is...

[0044]

[0045] 7: In the newly constructed local coordinate system, the laser measurement points of the laser tracker 5 are sequentially pointed to the horizontal measurement point 3 measured in step 4, and the T-Probe handheld probe 6 is used for precise marking, thereby achieving accurate marking of the horizontal measurement point 3 on the formal radome.

[0046] The above steps can accurately replicate the horizontal measurement point 3 on the left part of the radome, and can also be applied to replicate the horizontal measurement point 3 on the right part of the radome.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for rapidly supplementing horizontal measurement points on an antenna radome, characterized in that, Includes the following steps: Step S1: Pre-fabricate standard antenna radome parts; Step S2: During the assembly and finishing stage, install the standard radome component, mark the horizontal measurement points and local positioning reference points, and establish a local coordinate system; then, remove the standard radome component. Step S21: During the assembly and finishing stage, pre-install the standard radome component and mark the horizontal measurement points on the standard radome component; at this time, the physical coordinate system of the fuselage structure is consistent with the theoretical coordinate system of the aircraft. Step S22: Mark local positioning reference points on the fuselage skin adjacent to the radome; Step S23: Under the current laser tracker coordinate system, measure the horizontal measurement point HS and the local positioning reference point BS, and establish the local coordinate system CS; Step S3: After the formal radome is installed, take the local positioning reference points marked on the adjacent fuselage skin of the radome as the reference, and use the local coordinate system CS as the reference coordinate system to accurately make up the horizontal measurement points on the radome.

2. The method for rapidly supplementing horizontal measurement points on an antenna radome according to claim 1, characterized in that, In step S21, a dotting tool is used to mark horizontal measurement points on the standard part of the radome; in step S22, a crosshair dotting stamp is used to mark local positioning reference points on the adjacent fuselage skin of the radome.

3. The method for rapidly supplementing horizontal measurement points on an antenna radome according to claim 2, characterized in that, In step S22, the local positioning reference points are evenly distributed on the fuselage skin adjacent to the radome, and the number of distribution points is ≥7.

4. The method for rapidly supplementing horizontal measurement points on an antenna radome according to claim 1, characterized in that, Step S3 includes the following steps: Step S31: When the formal radome is installed, the formal radome is positioned and installed on the fuselage, and the fuselage is freed from the constraints of the jig tooling, and reaches a stable stage after stress release. Step S32: Under the current laser tracker coordinate system, obtain the local positioning reference point BO that is currently measured. Using the local positioning reference point BS in step S23 as the reference, calculate the rotation and translation matrix {R,T} between the local positioning reference point BO and the local positioning reference point BS through the iterative nearest neighbor algorithm, and transform the current laser tracker coordinate system to the local coordinate system CS constructed in step S23. Step S33: In the local coordinate system, the measurement points are sequentially pointed to the horizontal measurement points measured in step S23 and accurately marked, thereby achieving accurate marking of the horizontal measurement points on the radome.

5. The method for rapidly supplementing horizontal measurement points on an antenna radome according to claim 4, characterized in that, In step S32, the iterative nearest neighbor algorithm finds a rotation and translation transformation matrix {R,T} through iterative optimization, such that the point distance error between corresponding point pairs of local positioning reference point BO and local positioning reference point BS is minimized. Its optimization objective is: ； Where: N is the total number of local positioning reference points; R is the rotation matrix; T is the translation matrix.

Images