A large aircraft component attitude control method

Abstract

The present application relates to the field of numerical control machining process of aviation components, and particularly relates to a large aviation component attitude control method, which comprises the steps of determining an attitude control reference, measuring the attitude control reference, and adjusting the attitude of the component to be machined, wherein the attitude control reference satisfies the accessibility of measurement before and after the component to be machined is turned over; the measurement comprises in-machine measurement, the adjustment is based on the result of the in-machine measurement, and the adjustment aims to make the attitude of the component to be machined satisfy the maximum envelope principle. The component to be machined adopts a unified attitude control reference before and after being turned over, and satisfies the maximum envelope principle during numerical control machining, thereby reducing the attitude deviation of the component to be machined under in-machine clamping, ensuring the machining reliability and accuracy of the overall component to be machined, improving the manufacturing precision and shape accuracy, and making the shape tolerance of the formed overall weak-rigidity flexible body component meet the design and delivery requirements.

Description

Technical Field

[0001] This invention relates to the field of CNC machining technology for aerospace components, and in particular to a method for attitude control of large aerospace components. Background Technology

[0002] With technological advancements, CNC machining components are becoming increasingly larger, more integrated, and more complex, with component processing becoming more prevalent in CNC machining processes. Meanwhile, tooling and fixtures are evolving towards simplification and universality.

[0003] Currently, before CNC machining, both large parts and components have initial state changes due to their large size and weak rigidity. The increasingly simplified tooling cannot correct or compensate for these state changes. As a result, during CNC machining, the posture of the components due to the initial deformation does not conform to the theoretical position. The reference of large components cannot be unified in different processes. In particular, for overall weak rigidity flexible components that need to be flipped, different references are used before and after flipping, resulting in huge manufacturing errors.

[0004] In current manufacturing processes for large aerospace components, the attitude is typically controlled by measuring several process holes on the component. However, the overall weak stiffness of the flexible body component results in significant attitude deformation before and after flipping. The manufacturing error caused by attitude deviation can reach 0.5mm. Meanwhile, as the demands on aircraft performance continue to increase, the manufacturing tolerance for fuselage shape is generally ±0.1mm. Therefore, the contradiction between high manufacturing error and low manufacturing tolerance has become prominent and has long constrained the precision manufacturing and high-quality delivery of existing large aerospace components.

[0005] Therefore, there is an urgent need for a technical solution to address the problem that the attitude deviation caused by the initial deformation of large aerospace components, which is processed using different references before and after flipping, greatly affects the precision manufacturing and high-quality delivery of large aerospace components. Summary of the Invention

[0006] The purpose of this invention is to address the technical problem that the attitude deviation caused by the initial deformation of large aerospace components, which is often processed using different references before and after flipping, greatly affects the precision manufacturing and high-quality delivery of large aerospace components. This invention provides an attitude control method for large aerospace components.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for attitude control of large aerospace components includes the steps of determining an attitude control reference, measuring the attitude control reference, and adjusting the attitude of the component to be processed. The attitude control reference satisfies the measurability of the component before and after flipping. The measurement includes on-board measurement, and the adjustment is based on the results of the on-board measurement. The adjustment aims to ensure that the attitude of the component to be processed satisfies the maximum envelope principle.

[0009] This invention discloses a method for attitude control of large aerospace components. By adjusting the attitude of the component to be processed based on an attitude control benchmark that is measurably reachable before and after the component is flipped, the method ensures that the component adopts a unified benchmark before and after the flipping process and meets the maximum envelope principle during CNC machining. This reduces the attitude deviation of the component under machine clamping, ensuring the reliability and accuracy of the overall processing of the weak-stiffness flexible body component, improving its manufacturing precision and shape accuracy, and ensuring that the shape tolerance of the formed overall weak-stiffness flexible body component meets the design and delivery requirements.

[0010] As a preferred embodiment of the present invention, the attitude control reference includes a reference hole, which is obtained by selecting from the process holes used for assembly positioning of the component to be processed and / or provided by assembling a reference block on the component to be processed. This effectively associates the machining reference of the component to be processed with the assembly reference, thereby improving the CNC machining quality of the component while ensuring assembly accuracy.

[0011] As a preferred embodiment of the present invention, the attitude control reference includes a reference surface, which is provided by mounting a reference block on the component to be processed.

[0012] In a preferred embodiment of the present invention, the reference block is manufactured by machining. The reference block includes a positioning surface adapted to the shape of the component to be processed. The reference block is detachably connected to the component to be processed. The reference block is provided with the reference hole and / or the reference surface. This provides an auxiliary attitude control reference.

[0013] In a preferred embodiment of the present invention, the reference block is detachably connected to the process hole used for assembly positioning of the component to be processed. This ensures that the machining reference of the component to be processed is effectively associated with the assembly reference.

[0014] In a preferred embodiment of the present invention, the reference hole includes a process hole with a precision grade of at least H8, and the reference surface includes a machined surface with a flatness of not less than 0.02 mm. This provides a high-precision attitude control reference.

[0015] As a preferred embodiment of the present invention, the maximum envelope principle satisfies:

[0016] (DX 2 +DY2 +DZ 2 ) 1 / 2 ≤Δ

[0017] In the formula: DX is the difference between the measured value and the theoretical value of the attitude control reference in the X direction in the three-dimensional coordinate system; DY is the difference between the measured value and the theoretical value of the attitude control reference in the Y direction in the three-dimensional coordinate system; DZ is the difference between the measured value and the theoretical value of the attitude control reference in the Z direction in the three-dimensional coordinate system; Δ is the design shape tolerance of the component to be processed.

[0018] As a preferred embodiment of the present invention, the specific steps include: S0: Analyzing the structure of the component to be processed and determining the maximum contour position of the component; S1: Determining the attitude control reference; S2: Measuring the attitude control reference by means of machine measurement; S3: Adjusting the attitude of the component to be processed based on the measurement results of S2; S4: Repeating S2-S3 until the position of the component to be processed satisfies the maximum envelope principle. This ensures that the overall weak-stiffness flexible component is based on a unified attitude control reference before and after CNC machining, guaranteeing the effective transfer of references for component assembly, processing, and mating. It specifically solves the attitude control problem, enabling stable and efficient processing in CNC machine tools. When applied to the CNC machining of large aerospace components, it can improve the overall shape machining accuracy of the aircraft, which has significant and positive implications for improving the overall performance of the aircraft.

[0019] As a preferred embodiment of the present invention, the step of determining the attitude control reference includes the following process:

[0020] S1.1: Select process holes on the components to be processed for assembly positioning; S1.2: Select precision holes with a precision level of at least H8 from the process holes obtained in S1.1; S1.3: Analyze whether the location of the precision holes obtained in S1.2 contains the maximum outline of the components to be processed. If it does, verify the precision holes; if it does not, supplement the selection from the process holes obtained in S1.1 and then verify.

[0021] As a preferred embodiment of the present invention, the verification includes applying a fixed constraint to every two precision holes through finite element analysis calculation, determining whether the deformation of the structure between the two precision holes due to its own weight is less than 0.05 mm. If the condition is met, the precision hole is determined to be a reference hole for attitude control. If the condition is not met, one of the precision holes is used for positioning, and a process hole is selected from the process holes obtained in S1.1 for verification again.

[0022] As a preferred embodiment of the present invention, it further includes S1.4: analyzing and judging the measurability of the fine hole that meets the conditions after verification; if the measurability is not met, installing a reference block at the fine hole acquisition point, and providing an auxiliary attitude control reference through the reference block.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. By adjusting the attitude of the component to be processed based on the attitude control benchmark that is measurable before and after the flipping process, the component to be processed adopts a unified benchmark before and after the flipping process, and meets the maximum envelope principle during CNC machining. This reduces the attitude deviation of the component to be processed under machine clamping, which can ensure the processing reliability and accuracy of the overall weak stiffness flexible body component to be processed, improve its manufacturing precision and shape accuracy, and make the shape tolerance of the formed overall weak stiffness flexible body component meet the design and delivery requirements.

[0025] 2. The overall weak stiffness flexible body components are based on a unified attitude control benchmark before and after flipping in CNC machining, which ensures that the benchmark for component assembly, machining and mating is effectively transferred, and solves its attitude control problem in a targeted manner, enabling it to be machined smoothly and efficiently in CNC machine tools.

[0026] 3. It can improve the overall machining accuracy of the aircraft shape, which has an important and positive significance for improving the overall performance of the aircraft. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating an attitude control method for large aerospace components according to the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of the reference block described in this invention. Figure 1 ;

[0029] Figure 3 This is a schematic diagram of the structure of the reference block described in this invention. Figure 2 ;

[0030] Figure 4 This is a schematic diagram of the structure of the reference block described in this invention. Figure 3 ;

[0031] Figure 5 This is the attitude diagram of the fuselage under the machine clamp as described in Embodiment 4;

[0032] Figure 6 This is a cross-sectional view of the fuselage under machine clamping as described in Example 4.

[0033] icon:

[0034] 1-Reference block, 11-Reference hole, 12-Reference surface, 13-Positioning surface, 14-Bolt hole, 2-Machine body, 3-Tooling. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings.

[0036] 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.

[0037] Example 1

[0038] like Figure 1 As shown, a method for attitude control of a large aerospace component includes the steps of determining an attitude control reference, measuring the attitude control reference, and adjusting the attitude of the component to be processed. The attitude control reference satisfies the measurability of the component before and after flipping. The measurement includes in-flight measurement, and the adjustment is based on the results of the in-flight measurement. The adjustment aims to ensure that the attitude of the component to be processed satisfies the maximum envelope principle.

[0039] This embodiment provides a method for attitude control of large aerospace components. The measurement accessibility refers to the ability to reliably measure the component directly using on-machine measurement methods such as probes or vision. If reliable measurement cannot be achieved using on-machine measurement methods such as probes or vision, then measurement accessibility is not provided. The on-machine measurement refers to measuring the component to be processed by setting it on a machine tool fixture.

[0040] This embodiment of a large aerospace component attitude control method adjusts the attitude of the component to be processed based on an attitude control benchmark that is measurably reachable before and after the component is flipped. This ensures that the component adopts a unified attitude control benchmark before and after flipping, reducing the attitude deviation of the component before and after flipping under machine clamping. At the same time, the component satisfies the maximum envelope principle before and after CNC machining flipping, which can guarantee the processing reliability and accuracy of the overall weak stiffness flexible body component, improve its manufacturing precision and shape accuracy, and make the shape tolerance of the formed overall weak stiffness flexible body component meet the design and delivery requirements.

[0041] Preferably, the maximum envelope principle satisfies:

[0042] (DX 2 +DY 2 +DZ 2 ) 1 / 2 ≤Δ

[0043] In the formula: DX is the difference between the measured value and the theoretical value of the attitude control reference in the X direction in the three-dimensional coordinate system; DY is the difference between the measured value and the theoretical value of the attitude control reference in the Y direction in the three-dimensional coordinate system; DZ is the difference between the measured value and the theoretical value of the attitude control reference in the Z direction in the three-dimensional coordinate system; Δ is the design shape tolerance of the component to be processed.

[0044] Example 2

[0045] like Figure 1 As shown, this embodiment of the attitude control method for a large aerospace component is based on Embodiment 1, taking the attitude control reference as a reference hole as an example, and includes the following steps performed in sequence: S0: Analyze the structure of the component to be processed and determine the maximum contour position of the component to be processed; S1: Determine the attitude control reference; S2: Measure the attitude control reference by means of machine measurement; S3: Adjust the attitude of the component to be processed by means of measurement result of S2; S4: Repeat S2-S3 until the position of the component to be processed satisfies the maximum envelope principle.

[0046] Specifically, the step of determining the attitude control reference includes the following process: S1.1: Screening out the process holes on the component to be processed for assembly positioning; S1.2: Screening out the precision holes with a precision level of at least H8 from the process holes obtained in S1.1; S1.3: Analyzing whether the location of the precision hole obtained in S1.2 contains the maximum outline of the component to be processed. If it does, verify the precision hole; if it does not, supplement the selection from the process holes obtained in S1.1 and then verify.

[0047] Preferably, the verification includes applying a fixed constraint to every two precision holes through finite element analysis, determining whether the deformation of the structure between the two precision holes due to its own weight is less than 0.05 mm. If the condition is met, the precision hole is determined to be a reference hole for attitude control, i.e., an attitude control reference is obtained. If the condition is not met, one of the precision holes is used for positioning, and a process hole is selected from the process holes obtained in S1.1 for verification again.

[0048] Example 3

[0049] like Figures 1-6 As shown, the attitude control method for a large aerospace component in this embodiment, based on embodiment 2, further includes S1.4: analyzing and judging the measurability of the precision hole that meets the conditions after verification; if the measurability is not met, installing a reference block 1 at the acquisition point of the precision hole, and providing an auxiliary attitude control reference through the reference block 1.

[0050] In this embodiment of the attitude control method for a large aerospace component, since the precision hole obtained after verification in Embodiment 2 does not meet the measurement accessibility requirement, a reference block 1 is assembled at the precision hole, and the reference hole 11 or reference surface 12 set on the reference block 1 is used as an auxiliary attitude control reference.

[0051] Specifically, since the reference block 1 is assembled and connected with the selected precision holes that can be used as attitude control references, and the precision holes are process holes from the components to be processed for assembly positioning, the machining references of the components to be processed can be effectively associated with the assembly references, so as to improve the CNC machining quality of the components while ensuring assembly accuracy.

[0052] Specifically, the auxiliary attitude control reference can be a reference hole 11 or a reference surface 12. Preferably, a reference hole 11 and a reference surface 12 are provided on the reference block 1 at the same time. The reference hole 11 includes a precision hole with a precision level of not less than H8, and the reference surface 12 includes a machined surface with a flatness of not less than 0.02mm.

[0053] Preferred, such as Figures 2-4 As shown, the reference block 1 is manufactured by machining. The reference block 1 includes a positioning surface 13 that is adapted to the shape of the component to be processed. The reference block 1 is provided with precision bolt holes 14. In use, the positioning surface 13 fits the surface of the component to be processed, and the precision bolt holes 14 are assembled and connected with the selected precision holes or the process holes on the component to be processed for assembly.

[0054] Preferably, the shape and structure of the reference block 1 shown can be adjusted according to the actual shape of the component to be processed. Preferably, the reference block 1 includes a boss provided on its body, and a reference hole 11 and a reference surface 12 are provided on the boss.

[0055] Example 4

[0056] like Figures 1-6 As shown, this embodiment of the attitude control method for a large aerospace component is based on embodiments 1-3. Taking a component on the fuselage 2 of an aircraft as an example, the component is about 6000mm long. Analysis of its structure shows that it is an integral weak stiffness flexible body component. The maximum outline is symmetrical about the left and right sides along the symmetry plane of the fuselage 2. The component needs to be flipped on both the ventral and dorsal sides by CNC machining, which involves milling and drilling. However, since its attitude has a large difference along the length direction, its attitude must be adjusted before CNC machining to ensure that the attitude of the fuselage 2 is controllable during CNC machining.

[0057] For the aforementioned two-component fuselage structure, the conventional approach is to adjust the attitude of the component before and after the flipping process. The attitude adjustment is based on different attitude control references, which results in inconsistent attitude control references for the overall weak stiffness flexible body component before and after the flipping process. This severely restricts its overall machining accuracy and affects its assembly, mating and overall machine performance.

[0058] This embodiment of a method for attitude control of a large aerospace component is performed according to the following steps:

[0059] S1: Determine the attitude control reference.

[0060] Specifically, when the fuselage is clamped on fixture 3, the process holes used for assembly positioning on the component are first selected. Preferably, these process holes are located on the main load-bearing frame of fuselage 2 to improve the positional stability of the attitude adjustment reference. Then, from the obtained process holes, precision holes with an accuracy level of H8 or above are selected. Preferably, these precision holes are symmetrically distributed along the symmetry plane of fuselage 2. Next, it is analyzed whether the location of the precision hole includes the maximum outline of fuselage 2. If the location of the precision hole includes the maximum outline of fuselage 2, the precision hole is verified by finite element calculation.

[0061] Specifically, the verification process includes applying fixed constraints to two adjacent precision holes along the longitudinal direction of the fuselage 2 to obtain the amount of deformation of the structure between them due to its own weight.

[0062] In this embodiment, the location of the fine hole includes the maximum outline of the fuselage 2, and the verification results include: the deformation of the structure between the two due to its own weight is about 0.048mm, which meets the requirement that the deformation of the structure between the two due to its own weight is less than 0.05mm. Therefore, it is determined that the obtained fine hole can be used as a reference for attitude control.

[0063] Furthermore, since the structure of the fuselage 2 in this embodiment makes it impossible to directly measure the precision holes located on its side wall by the probe, the precision holes obtained after verification that can be used as attitude control references do not have measurement accessibility. Therefore, a reference block 1 is assembled in the acquisition of precision holes, and the attitude control reference is provided by the reference hole 11 and the reference surface 12 set on the reference block 1.

[0064] Specifically, reference blocks 1 are symmetrically arranged on the left and right sides of the fuselage 2, preferably 12. The reference blocks 1 are completely fitted with the main load-bearing frame of the fuselage 2 through the positioning surface 13. Multiple precision bolt holes 14 are arranged on the reference blocks 1. The precision bolt holes 14 are connected to the precision holes or assembly process holes selected on the fuselage 2. At the same time, reference holes 11 and / or reference surfaces 12 are provided on the reference blocks 1 to provide reference holes 11 and / or reference surfaces 12 that can measure and obtain the attitude information of the fuselage 2. Preferably, the reference blocks 1 are provided with both reference holes 11 and reference surfaces 12.

[0065] S2: Measurement attitude control reference.

[0066] Specifically, the fuselage attitude information is obtained by measuring the reference hole 11 and reference surface 12 on the reference block 1 using an in-machine measurement method.

[0067] S3: Adjust the posture of the component to be processed.

[0068] Specifically, the attitude of fuselage 2 is adjusted based on the S2 measurement results to ensure that the attitude of fuselage 2 meets the maximum envelope principle as much as possible.

[0069] S4: Repeat S2-S3 until the position of fuselage 2 satisfies the maximum envelope principle.

[0070] Specifically, the design requires the machining tolerance of fuselage 2 to be ±0.1mm. According to the maximum envelope principle formula, we know that:

[0071] (DX 2 +DY 2 +DZ 2 ) 1 / 2 ≤0.1

[0072] In the formula: DX is the difference between the measured value and the theoretical value of the attitude control reference in the X direction in the three-dimensional coordinate system; DY is the difference between the measured value and the theoretical value of the attitude control reference in the Y direction in the three-dimensional coordinate system; DZ is the difference between the measured value and the theoretical value of the attitude control reference in the Z direction in the three-dimensional coordinate system.

[0073] Specifically, the X, Y, and Z directions are the conventional coordinate system directions of the aircraft fuselage.

[0074] This embodiment of a large aerospace component attitude control method enables the fuselage 2 component of the overall weak stiffness flexible body component to be based on a unified attitude control benchmark before and after the flipping process in CNC machining. This allows it to be machined smoothly and efficiently in the CNC machine tool, and the machine clamping attitude deviation can be kept within 0.2mm during CNC machining. It achieves CNC machining with a shape tolerance of ±0.1mm, which can improve the overall shape machining accuracy of the aircraft and has important and positive significance for improving the overall performance of the aircraft.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for attitude control of large aerospace components, characterized in that, The process includes steps such as analyzing the structure of the component to be processed, determining the attitude control reference, measuring the attitude control reference, and adjusting the attitude of the component to be processed. The attitude control reference satisfies the measurement accessibility of the component before and after the flipping process. The measurement includes in-machine measurement, and the adjustment is based on the results of the in-machine measurement, with the goal of ensuring that the orientation of the component to be processed satisfies the maximum envelope principle. The attitude control reference includes a reference hole (11), which is obtained by screening from process holes used for assembly positioning of the component to be processed and / or provided by mounting a reference block (1) on the component to be processed; The attitude control reference includes a reference surface (12), which is provided by mounting a reference block (1) on the component to be processed; The step of analyzing the structure of the component to be processed is used to determine the maximum contour position of the component to be processed. The positions of the reference hole (11) and the reference surface (12) both contain the maximum contour position of the component to be processed. The in-machine measurement refers to measuring the component to be processed by setting it on the machine tool fixture. This includes the following steps performed sequentially: S0: Analyze the structure of the component to be processed and determine the maximum contour position of the component to be processed; S1: Determine the attitude control reference; S1.1: Select the process holes on the components to be processed for assembly positioning; S1.2: Select the fine holes with a precision grade of at least H8 from the process holes obtained in S1.1; S1.3: Analyze whether the location of the precision hole obtained in S1.2 contains the maximum outline of the component to be processed. If it does, verify the precision hole; if it does not, select from the process holes obtained in S1.1 and then verify. The verification includes applying a fixed constraint to every two precision holes through finite element analysis calculations, determining whether the deformation of the structure between the two precision holes due to its own weight is less than 0.05 mm. If the condition is met, the precision hole is determined to be a reference hole for attitude control. If the condition is not met, one of the precision holes is used for positioning, and a process hole is selected from the process holes obtained in S1.1 for verification again. S1.4: Analyze and judge the measurement accessibility of the fine hole that meets the conditions after verification. If the measurement accessibility is not met, install a reference block at the fine hole location and provide auxiliary attitude control reference through the reference block (1). S2: Measure the attitude control reference by measuring the attitude control reference in a machine measurement manner; S3: Adjust the orientation of the component to be processed based on the measurement results of S2; S4: Repeat S2-S3 until the position of the component to be processed satisfies the maximum envelope principle.

2. The attitude control method for a large aerospace component as described in claim 1, characterized in that, The reference block (1) is manufactured by machining. The reference block (1) includes a positioning surface (13) adapted to the shape of the component to be processed. The reference block (1) is detachably connected to the component to be processed. The reference block (1) is provided with a reference hole (11) and / or a reference surface (12).

3. The attitude control method for a large aerospace component as described in claim 2, characterized in that, The reference hole (11) includes a process hole with a precision grade of at least H8, and the reference surface (12) includes a machined surface with a flatness of not less than 0.02 mm.

4. The attitude control method for a large aerospace component as described in claim 1, characterized in that, The maximum envelope principle satisfies: (DX 2 +DY 2 +DZ 2 ) 1 / 2 ≤Δ In the formula: DX is the difference between the measured value and the theoretical value of the attitude control reference in the X direction in the three-dimensional coordinate system; DY is the difference between the measured value and the theoretical value of the attitude control reference in the Y direction in the three-dimensional coordinate system. DZ is the difference between the measured value and the theoretical value of the attitude control reference in the Z direction in a three-dimensional coordinate system. Δ represents the design tolerance of the component to be processed.

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