Method of modifying an aircraft section

Abstract

The present application belongs to the technical field of aircraft assembly, and discloses a kind of aircraft section modification method, it includes the following steps: S1, level aircraft;S2, select multiple horizontal measurement points, measure the initial space coordinate value of each horizontal measurement point under preset space coordinate system;S3, obtain the theoretical coordinate value of each horizontal measurement point from aircraft design drawing, based on preset space coordinate system, the initial space coordinate value of each horizontal measurement point and the theoretical coordinate value of each horizontal measurement point, theoretical whole machine coordinate system is fitted;S4, with self-weight correction coefficient, the theoretical whole machine coordinate system is corrected, and the standard whole machine coordinate system without self-weight influence is obtained;S5, in the standard whole machine coordinate system, the first actual coordinate value of each horizontal measurement point on the section to be disassembled is measured again, and each horizontal measurement point on the section to be disassembled is adjusted from the first actual coordinate value to the theoretical coordinate value under the standard whole machine coordinate system;S6, separate the section to be disassembled from the aircraft, install the section to be installed, and complete the modification.

Description

Technical Field

[0001] This invention relates to the field of aircraft assembly technology, and in particular to a method for modifying aircraft sections. Background Technology

[0002] When conducting certain test flight maneuvers, it is necessary to modify the fully assembled aircraft for test flights.

[0003] Some test flight projects require modifications to the aircraft fuselage. Currently, the common modification method is to add components directly to the aircraft body, such as installing parachute compartments or adding structural reinforcements.

[0004] However, this method makes it difficult to ensure the coordination between the separation surfaces of the new structural components and the original structure, thereby affecting the realization of the structural functions and consequently affecting factors such as aircraft attitude and aerodynamic surfaces, making it difficult to guarantee the flight performance of the modified aircraft. Summary of the Invention

[0005] The purpose of this invention is to provide a method for modifying aircraft components, ensuring that the modification meets the requirements of the aircraft design drawings and that the relative positions, symmetry, and attitudes of the various components of the aircraft are sufficiently accurate.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The method for modifying aircraft sections includes the following steps:

[0008] S1. Level the aircraft to keep it horizontal in both span and heading.

[0009] S2. Select multiple horizontal measurement points on the aircraft and measure the initial spatial coordinate values ​​of each horizontal measurement point in any preset spatial coordinate system.

[0010] S3. Obtain the theoretical coordinate values ​​of each horizontal measurement point from the aircraft design drawings. Based on the preset spatial coordinate system, the initial spatial coordinate values ​​of each horizontal measurement point, and the theoretical coordinate values ​​of each horizontal measurement point, fit the theoretical whole-aircraft coordinate system of the aircraft.

[0011] S4. Correct the theoretical whole-aircraft coordinate system with the self-weight correction factor to obtain a standard whole-aircraft coordinate system without the influence of self-weight. The self-weight correction factor is obtained from the aircraft design data.

[0012] S5. Remeasure the first actual coordinate values ​​of each horizontal measuring point on the section to be disassembled under the standard full-machine coordinate system. Using the theoretical coordinate values ​​under the standard full-machine coordinate system as a reference, adjust the first actual coordinate values ​​of each horizontal measuring point on the section to be disassembled to the theoretical values ​​under the standard full-machine coordinate system.

[0013] S6. Remove the fasteners used to secure the section to be disassembled, separate the section to be disassembled from the aircraft, install the section to be installed, and complete the modification.

[0014] As an optional embodiment of the aircraft section modification method, the horizontal measurement point selected on the fuselage in step S2 is located on the maximum width line and / or the lower zero longitudinal line.

[0015] As an optional embodiment of the aircraft section modification method, the horizontal measurement point selected on the wing in step S2 is located at the junction of the front spar and the wing rib or the junction of the rear spar and the wing rib, and is located on the lower wing surface.

[0016] As an optional embodiment of the aircraft section modification method, the installation of the section to be installed in step S6 includes: selecting multiple horizontal measurement points on the section to be installed, adjusting the attitude of the section to be installed in the standard whole-aircraft coordinate system so that the horizontal measurement points of the section to be installed are adjusted to the theoretical coordinate values, and fastening the section to be installed to the aircraft to complete the modification.

[0017] As an optional embodiment of the aircraft section modification method, step S7 is included after step S6: coordinate measurement of the horizontal measurement points of the modified aircraft in the standard whole-aircraft coordinate system to obtain the second actual coordinate value. If the deviation between the second actual coordinate value and the theoretical coordinate value is less than the preset displacement deviation, the assembly is qualified; otherwise, the attitude of the section to be installed is adjusted and the section to be installed is reinstalled.

[0018] As an optional embodiment of the aircraft section modification method, the section to be disassembled includes the section body and auxiliary components connected to the section body;

[0019] After step S4 and before step S5, remove the auxiliary parts from the main body of the section;

[0020] In step S5, the first actual coordinate values ​​of each horizontal measurement point on the main body of the section are remeasured in the standard full-machine coordinate system. With the theoretical coordinate values ​​in the standard full-machine coordinate system as a reference, the first actual coordinate values ​​of each horizontal measurement point on the main body of the section are adjusted to the theoretical coordinate values ​​in the standard full-machine coordinate system.

[0021] In step S6, the fasteners used to fix the main body of the segment are removed, the main body of the segment is separated from the aircraft, and the segment to be installed is installed.

[0022] As an optional embodiment of the aircraft section modification method, the main body of the section is the tail section of the fuselage. In step S5, the tail section of the fuselage is lifted upward by the lifting mechanism, and the horizontal measurement points on the tail section of the fuselage are adjusted from the first actual coordinate value to the theoretical coordinate value under the standard whole-aircraft coordinate system.

[0023] As an alternative embodiment of the aircraft section modification method, the auxiliary components include one or more of the following: cabin doors, elevators, hydraulic lines, electrical wiring, and actuators.

[0024] As an optional embodiment of the aircraft section modification method, step S1 specifically includes: selecting at least two reference points on the fuselage to construct a heading reference line, selecting at least two reference points on the wing to construct a spanwise reference line, and adjusting both the heading reference line and the spanwise reference line to remain horizontal.

[0025] As an optional embodiment of the aircraft section modification method, between steps S1 and S2, the following is also included: assembling a modification docking frame on the aircraft to maintain the aircraft's attitude.

[0026] Beneficial effects:

[0027] The aircraft section modification method provided by this invention involves leveling the aircraft to maintain horizontality in both spanwise and yaw directions. At this point, the aircraft's actual attitude is formed by the deformation of the designed attitude due to its own weight. Multiple horizontal measurement points on the aircraft are selected, and their initial spatial coordinate values ​​are measured in any preset spatial coordinate system, thus obtaining the initial spatial coordinate values ​​under the actual attitude. The theoretical coordinate values ​​of each horizontal measurement point are obtained from the aircraft design drawings. Based on the preset spatial coordinate system, the initial spatial coordinate values ​​of each horizontal measurement point, and the theoretical coordinate values ​​of each horizontal measurement point, the theoretical overall aircraft coordinate system is fitted to obtain the theoretical overall aircraft coordinate system under the influence of its own weight. This is then used to modify the aircraft's structure by its own weight. A positive coefficient is used to correct the theoretical whole-aircraft coordinate system, resulting in a standard whole-aircraft coordinate system unaffected by self-weight. The first actual coordinate values ​​of each horizontal measurement point on the section to be disassembled are then remeasured in the standard whole-aircraft coordinate system. Using the theoretical coordinate values ​​in the standard whole-aircraft coordinate system as a reference, the first actual coordinate values ​​of each horizontal measurement point on the section to be disassembled are adjusted to the theoretical coordinate values ​​in the standard whole-aircraft coordinate system. This adjusts the aircraft from its actual attitude, affected by self-weight, to the attitude designed in the drawings. Under this designed attitude, the section to be disassembled is replaced with the section to be installed, ensuring that the aircraft modification meets the requirements of the aircraft design drawings and that the relative positions, symmetry, and attitudes of the various components of the aircraft are sufficiently accurate. Attached Figure Description

[0028] Figure 1 This is a flowchart of the aircraft section modification method provided in the embodiment of the present invention. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0030] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0033] like Figure 1 As shown, this embodiment provides a method for modifying aircraft sections. Compared with the prior art of directly adding structural components to the aircraft body, this method replaces the section to be disassembled with the section to be installed. Specifically, the section to be disassembled is an aircraft fuselage section without structural components, and the section to be installed is an aircraft fuselage section with structural components already installed.

[0034] During aircraft section installation, a laser tracker is typically used in conjunction with ground ERS points to establish the overall aircraft coordinate system. However, once the aircraft is removed from the assembly line after production, it is no longer on the assembly rack. When modifying aircraft sections, it becomes difficult to perfectly align the overall aircraft coordinate system established during manufacturing with the aircraft again, necessitating the reconstruction of the overall aircraft coordinate system.

[0035] The aircraft section modification method provided in this embodiment specifically includes the following steps:

[0036] S1. Level the aircraft so that it remains horizontal in both spanwise and heading directions. At this point, the actual attitude of the aircraft is formed by the deformation of the attitude designed on the drawing due to its own weight. Further, step S1 specifically includes: selecting at least two reference points on the fuselage to construct a heading reference line, selecting at least two reference points on the wing to construct a spanwise reference line, and adjusting both the heading reference line and the spanwise reference line to remain horizontal.

[0037] S2. Select multiple horizontal measurement points on the aircraft and measure the initial spatial coordinate values ​​of each horizontal measurement point in any preset spatial coordinate system to obtain the initial spatial coordinate values ​​under the actual attitude. The number of horizontal measurement points should not be less than 3, for example, 6 or 10.

[0038] S3. Obtain the theoretical coordinate values ​​of each horizontal measurement point from the aircraft design drawings. Based on the preset spatial coordinate system, the initial spatial coordinate values ​​of each horizontal measurement point, and the theoretical coordinate values ​​of each horizontal measurement point, fit the theoretical whole-aircraft coordinate system of the aircraft, that is, obtain the theoretical whole-aircraft coordinate system under the influence of its own weight.

[0039] S4. Correct the theoretical whole-aircraft coordinate system with the self-weight correction factor to obtain a standard whole-aircraft coordinate system without the influence of self-weight. The self-weight correction factor is obtained from the aircraft design data.

[0040] S5. Remeasure the first actual coordinate values ​​of each horizontal measuring point on the section to be disassembled in the standard full-aircraft coordinate system. The type of measuring equipment used for remeasurement is not limited, such as laser trackers and target balls. Using the theoretical coordinate values ​​in the standard full-aircraft coordinate system as a reference, adjust the first actual coordinate values ​​of each horizontal measuring point on the section to be disassembled from the theoretical coordinate values ​​in the standard full-aircraft coordinate system, thereby adjusting the aircraft, which is in its actual attitude due to its own weight, to the attitude designed in the drawings, and eliminating the shearing force on the fasteners used to fix the section to be disassembled.

[0041] S6. Remove the fasteners used to secure the section to be disassembled, detach the section from the aircraft, install the section to be installed, and complete the modification. In other words, by replacing the section to be disassembled with the section to be installed in the design attitude on the drawings, the aircraft modification is ensured to meet the requirements of the aircraft design drawings, and the relative positions, symmetry, and attitudes of the various components of the aircraft are sufficiently accurate.

[0042] The aircraft section modification method provided in this embodiment eliminates aircraft attitude deformation caused by factors other than its own weight by leveling the aircraft, ensuring that the actual aircraft attitude is primarily affected only by its own weight. Under the actual attitude, a preset spatial coordinate system is converted into a theoretical full-aircraft coordinate system using a spatial coordinate transformation formula. Then, a weight correction coefficient is used to eliminate the weight factor in the theoretical full-aircraft coordinate system, thereby establishing a standard full-aircraft coordinate system. Within the standard full-aircraft coordinate system, the positions of each aircraft section under the actual attitude can be accurately adjusted, ensuring that the aircraft before and after modification remains in the attitude designed in the drawings. This helps ensure that the aircraft modification meets the requirements of the aircraft design drawings and guarantees sufficient accuracy in the relative positions, symmetry, and attitude of the various aircraft components.

[0043] In this embodiment, the horizontal measurement point selected on the fuselage in step S2 is located on the maximum width line and / or the lower zero line. Compared with other parts of the fuselage, the fuselage structure at the maximum width line and the lower zero line has greater structural rigidity and smaller deformation. Positioning the horizontal measurement point on the fuselage at these locations helps improve the accuracy of establishing the theoretical whole-machine coordinate system. Moreover, the maximum width line and the lower zero line help ensure the accessibility of the measurement.

[0044] In this embodiment, the horizontal measurement point selected on the wing in step S2 is located at the junction of the front spar and the wing rib or the junction of the rear spar and the wing rib, and is located on the lower wing surface. The structural stiffness and deformation at the junction of the front spar and the wing rib or the junction of the rear spar and the wing rib are large, which is beneficial to improving the accuracy of establishing the theoretical whole-aircraft coordinate system, while the lower wing surface is beneficial to ensuring the accessibility of the measurement and facilitating the measurement.

[0045] Optionally, the segment to be disassembled includes the segment body and auxiliary components connected to the segment body; after step S4 and before S5, the auxiliary components are removed from the segment body; in step S5, the first actual coordinate values ​​of each horizontal measuring point on the segment body are remeasured in the standard full-aircraft coordinate system, and the theoretical coordinate values ​​in the standard full-aircraft coordinate system are used as a reference to adjust each horizontal measuring point on the segment body from the first actual coordinate values ​​to the theoretical coordinate values ​​in the standard full-aircraft coordinate system; in step S6, the fasteners used to fix the segment body are removed, the segment body is separated from the aircraft, and the segment to be installed is installed. Removing the auxiliary components in advance facilitates the adjustment of the position of the segment body, so that the actual position of the segment body corresponds to the theoretical coordinate values, and avoids interference during the adjustment process.

[0046] Of course, when dismantling auxiliary components, the actual position of the auxiliary components can be adjusted to correspond to the theoretical coordinate value based on the standard whole-aircraft coordinate system. This facilitates the elimination of shearing forces on the fasteners between the auxiliary components and the main body of the section, and is beneficial for separating the auxiliary components from the main body of the section. In this embodiment, the auxiliary components include one or more of the following: hatch, elevator, hydraulic lines, electrical wiring, and actuators. In this embodiment, the horizontal measurement points on the section to be dismantled are selected on the horizontal stabilizer, the vertical stabilizer, and the rudder.

[0047] In this embodiment, the main body of the section is the tail section of the fuselage. In step S5, the tail section of the fuselage is lifted upward using a lifting mechanism, and the horizontal measuring points on the tail section of the fuselage are adjusted from the first actual coordinate value to the theoretical coordinate value under the standard full-aircraft coordinate system. That is to say, through the lifting operation, an upward support force is provided to the tail section of the fuselage, which counteracts the influence of the tail section's own weight, and restores the tail section of the fuselage to the posture designed in the drawings.

[0048] In this embodiment, the step between S1 and S2 further includes: assembling a modified docking frame on the aircraft to maintain its attitude. The modified docking frame is existing technology, and its specific principles and structure will not be described here.

[0049] To install the component to be installed on the aircraft in the orientation designed on the drawings, step S6 involves: selecting multiple horizontal measurement points on the component to be installed; adjusting the orientation of the component to be installed in the standard full-aircraft coordinate system to align the horizontal measurement points to the theoretical coordinate values; and then securely connecting the component to the aircraft to complete the modification. In this embodiment, after the tail section is installed in the above manner, the auxiliary components are then installed on the tail section. Furthermore, after the orientation of the tail section is adjusted, connection holes are manufactured on the process separation surface of the tail section, and fasteners are passed through the connection holes for fixation.

[0050] In this embodiment, step S7 is included after step S6: coordinate measurements are performed on the horizontal measurement points of the modified aircraft in the standard full-aircraft coordinate system to obtain second actual coordinate values. If the deviation between the second actual coordinate value and the theoretical coordinate value is less than a preset displacement deviation, the assembly is qualified; otherwise, the attitude of the section to be assembled is adjusted, and the section to be assembled is reinstalled. In this embodiment, the preset displacement deviation is the displacement difference between the first actual coordinate value and the theoretical coordinate value.

[0051] In addition to being applicable to the modification of the tail section of an aircraft, the aircraft section modification method provided in this embodiment is also applicable to other sections of the aircraft fuselage, such as the mid-section or nose section.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for modifying aircraft sections, characterized in that, Includes the following steps: S1. Level the aircraft to keep it horizontal in both span and heading. S2. Select multiple horizontal measurement points on the aircraft and measure the initial spatial coordinate values ​​of each horizontal measurement point in any preset spatial coordinate system. S3. Obtain the theoretical coordinate values ​​of each horizontal measurement point from the aircraft design drawings. Based on the preset spatial coordinate system, the initial spatial coordinate values ​​of each horizontal measurement point, and the theoretical coordinate values ​​of each horizontal measurement point, fit the theoretical whole-aircraft coordinate system of the aircraft. S4. Correct the theoretical whole-aircraft coordinate system with the self-weight correction factor to obtain a standard whole-aircraft coordinate system without the influence of self-weight. The self-weight correction factor is obtained from the aircraft design data. S5. Remeasure the first actual coordinate values ​​of each horizontal measuring point on the section to be disassembled under the standard full-machine coordinate system. Using the theoretical coordinate values ​​under the standard full-machine coordinate system as a reference, adjust the first actual coordinate values ​​of each horizontal measuring point on the section to be disassembled to the theoretical values ​​under the standard full-machine coordinate system. S6. Remove the fasteners used to secure the section to be disassembled, separate the section to be disassembled from the aircraft, install the section to be installed, and complete the modification; The section to be dismantled includes the main body of the section and the auxiliary components connected to the main body of the section; After step S4 and before step S5, remove the auxiliary parts from the main body of the section; In step S5, the first actual coordinate values ​​of each horizontal measurement point on the main body of the section are remeasured in the standard full-machine coordinate system. With the theoretical coordinate values ​​in the standard full-machine coordinate system as a reference, the first actual coordinate values ​​of each horizontal measurement point on the main body of the section are adjusted to the theoretical coordinate values ​​in the standard full-machine coordinate system. In step S6, the fasteners used to fix the main body of the segment are removed, the main body of the segment is separated from the aircraft, and the segment to be installed is installed.

2. The aircraft section modification method according to claim 1, characterized in that, In step S2, the horizontal measurement point selected on the machine body is located on the maximum width line and / or the lower zero line.

3. The aircraft section modification method according to claim 1, characterized in that, In step S2, the horizontal measurement point selected on the wing is located at the junction of the front spars and wing ribs or the junction of the rear spars and wing ribs, and is located on the lower wing surface.

4. The aircraft section modification method according to claim 1, characterized in that, Step S6 involves installing the section to be installed, which includes: selecting multiple horizontal measurement points on the section to be installed, adjusting the attitude of the section to be installed in the standard whole-aircraft coordinate system so that the horizontal measurement points of the section to be installed are adjusted to the theoretical coordinate values, and then fastening the section to be installed to the aircraft to complete the modification.

5. The aircraft section modification method according to claim 4, characterized in that, Step S6 is followed by step S7: coordinate measurement of the horizontal measurement points of the modified aircraft in the standard whole-aircraft coordinate system to obtain the second actual coordinate value. If the deviation between the second actual coordinate value and the theoretical coordinate value is less than the preset displacement deviation, the assembly is qualified; otherwise, the attitude of the section to be assembled is adjusted and the section to be assembled is reinstalled.

6. The aircraft section modification method according to claim 1, characterized in that, The main body of the section is the tail section of the fuselage. In step S5, the tail section of the fuselage is lifted upward by the lifting mechanism, and the horizontal measurement points on the tail section of the fuselage are adjusted from the first actual coordinate value to the theoretical coordinate value under the standard whole-machine coordinate system.

7. The aircraft section modification method according to claim 6, characterized in that, The auxiliary components include one or more of the following: hatch, elevator, hydraulic lines, electrical wiring, and actuators.

8. The aircraft section modification method according to claim 1, characterized in that, Step S1 specifically includes: selecting at least two reference points on the fuselage to construct a heading reference line, selecting at least two reference points on the wing to construct a spanwise reference line, and adjusting both the heading reference line and the spanwise reference line to remain horizontal.

9. The aircraft section modification method according to claim 1, characterized in that, Between steps S1 and S2, the process also includes: assembling a modified docking frame on the aircraft to maintain its attitude.

Images