Product structure characteristic-based aircraft assembly drilling process verification method

Abstract

The invention discloses an aircraft assembly drilling process verification method based on product structural characteristics, and the method comprises the steps: presetting a preassembling scheme based on the product structural characteristics, and adjusting the connection mode and connection spacing of a pre-connection fastener to guarantee the overall stability after preassembling; based on the component assembling scheme, an identification scheme of the pre-assembled fastening nails is reasonably selected and matched; an identification track of the preassembled fastening nail is formulated based on a path optimal principle, and positioning of a product structure form under a global coordinate system is completed; manufacturing indexes of different working condition differences of all hole sites are determined based on aircraft assembly hole manufacturing process correlation parameters; presetting a test working condition based on the manufacturing index of a certain hole site, and enabling the current test working condition to be equivalent to the product working condition; step-by-step optimization is carried out on a hole making process parameter domain based on a test panel test, an optimization result is directionally migrated to product hole making, and process parameter making is completed; and a process strategy is called according to the accumulated information, and hole making of the complete hole making molded surface is completed, so that the correctness of equipment after wire entering is ensured, and the suitability of the process strategy is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic hole making, in particular to an aircraft assembly hole making process verification method based on product structure characteristics. BACKGROUND

[0002] In the manufacture and assembly of large and complex components of aviation equipment, hundreds of thousands of mechanical connection holes need to be drilled, and the hole making workload is large. The hole making efficiency and processing quality are the key to ensure the performance and reliability of the aircraft. In order to reduce the weight of the aircraft structure and improve the structural strength, lightweight alloys and composite materials are widely used in new aircraft models, and the use of difficult-to-machine materials in a large area makes the hole making operation in the assembly process of the aircraft face greater challenges. Especially the high complexity of the internal structure of the same assembly part leads to obvious differences in the working conditions of each hole making area. The difficulty of machining the material itself and the complexity of the working conditions lead to poor consistency of the hole making results, and usually require multiple steps of repeated adjustment to achieve the final indicators.

[0003] In order to enhance the adaptability of the hole making process to various working conditions and improve the consistency of the hole making results, a convenient, efficient and adaptable hole making process full-process verification method needs to be developed to quickly form an adaptive process scheme for different product structures, improve the compatibility of the hole making system for different application scenarios, and realize high-precision hole making. SUMMARY

[0004] In order to solve the above problems, the present application provides an aircraft assembly hole making process verification method based on product structure characteristics, to solve the problem of low precision caused by blind hole making under the condition that the product feature information verification is not comprehensive and stable in the prior art.

[0005] An aircraft assembly hole making process verification method based on product structure characteristics, comprising: Step 1: preset a pre-assembly scheme based on product structure characteristics, adjust the connection mode and connection distance of the pre-connection fastener to ensure the overall stability after pre-assembly; Step 2: reasonably select the identification scheme of the pre-assembly fastener based on the material category of the component to be assembled; Step 3: develop an identification trajectory of the pre-assembly fastener based on the path optimization principle, and complete the positioning of the product structure form in the global coordinate system; Step 4: determine the manufacturing indicators of each hole based on the correlation parameters of the aircraft assembly hole making process; Step 5: preset the test working condition based on the manufacturing indicators of a certain hole, so that the current test working condition is equivalent to the product working condition; Step 6: perform step-by-step optimization of the hole making process parameter domain based on the test plate test, and perform directional migration of the optimization results to the product hole making to complete the process parameter development; Step 7: According to the manufacturing index and process parameters of each hole position, the process strategy is called to complete the hole making of the complete hole type surface.

[0006] Preferably, the pre-installation scheme of the pre-set product in step 1 includes a single-row hole pre-installation connection scheme and a double-row hole pre-installation connection scheme. The single-row hole pre-installation connection principle is to pre-connect according to a fixed hole spacing, and the pre-connected fastener ratio is not greater than 1 / 10 of the total number of holes. The double-row hole pre-installation connection principle is to diagonally arrange two temporary connection fasteners, and the ratio of the temporary connection fasteners is not greater than 30% to 40% of the total number of holes. Preferably, the pre-installed fastener identification scheme in step 2 includes but is not limited to image visual identification technology, magnetic induction identification technology, and ultrasonic wave identification technology. Preferably, the identification trajectory of the pre-installed fastener in step 3 includes but is not limited to starting from the identification reference mark and following an arch-shaped route or a back-shaped route. The identification object includes the features and shapes of different fastener heads, holes, and pockets, and is not limited to "single" slots, "cross" slots, circles, internal hexagons, and external hexagons. Preferably, the positioning of the product structure in the global coordinate system based on the coordinates of the reference mark in step 3 includes: Grouping the reference pins by region, linearly interpolating the coordinates of the reference pins in the same group based on the identification results of the reference pins in the product coordinate system; According to the number of holes to be made within the reference pin spacing, the corresponding coordinates are evenly distributed to complete the positioning of each hole to be made; Preferably, the aircraft assembly hole making process related parameters in step 4 include but are not limited to: Hole spacing tolerance x1, hole row spacing tolerance x2, hole edge spacing tolerance x3, target hole diameter d, target counterbore diameter D, target counterbore depth H, target hole perpendicularity tolerance a, inner wall roughness R, and entrance and exit burr height h. Step 41, No. 001 hole position, manufacturing index requirements: hole spacing tolerance x1 = 0.5 mm, hole row spacing tolerance x2 = 0.5 mm, hole edge spacing tolerance x3 = 0.2 mm, target hole diameter d = 6 ± 0.02 mm, target counterbore diameter D = 12 ± 0.03 mm, target hole perpendicularity tolerance a = 90° ± 0.5°. Step 42, No. 002 hole position, manufacturing index requirements: hole spacing tolerance x1 = 0.5 mm, hole row spacing tolerance x2 = 0.5 mm, hole edge spacing tolerance x3 = 0.2 mm, target hole diameter d = 8 ± 0.02 mm, target counterbore diameter D = 16 ± 0.03 mm, target hole perpendicularity tolerance a = 90° ± 0.5°. Step 43, according to the specific index requirements of each hole site, mark in turn.

[0007] Preferably, the preset test working condition equivalent method in step 5 comprises: Step 51, identify the local characteristics of each hole site, including but not limited to local curvature, local stiffness.

[0008] Step 52, facing the test object, complete the local stiffness calibration under each structure by adjusting the thickness and size of the test plate; Step 53, facing the test object, complete the local curvature calibration of different experimental objects by selecting test pieces with different curvatures; Step 53, match the test objects with the same local curvature and local stiffness of the product hole site characteristics in the test working condition as the equivalent group; Step 54, repeat the above steps until all product hole site working conditions and test working conditions are equivalent.

[0009] Preferably, the test plate test in step 6 comprises the following two sub-tests: Step 61, single-layer test plate test: according to the material category corresponding to a certain hole site of the product, perform process test to obtain a process scheme for adapting material characteristics as the experimental purpose, until all hole sites are covered.

[0010] Step 62, laminated test plate test: according to the material combination corresponding to a certain hole site of the product, perform process test to obtain a process scheme for adapting structure characteristics as the experimental purpose, until all hole sites are covered.

[0011] Preferably, the step-by-step optimization scheme for the hole forming process parameter domain in the test plate test comprises the following sub-steps: Step 611, single-layer test plate test includes but is not limited to compression damage threshold calibration test, process parameter domain optimization test for hole size related indicators; Wherein the compression damage threshold calibration test is to obtain the maximum compression force threshold applied in the hole forming process without damaging the surface integrity of the product; Wherein the process parameter domain optimization test for hole size related indicators is to obtain the allowable value boundary by preliminary optimization of process parameters under the premise of meeting part of the manufacturing indicators; Wherein the hole size related indicators include but are not limited to hole diameter accuracy, surface quality, entrance and exit damage; Step 612, laminated test plate test further restores the structure characteristics of the product, and supplements the verification of process parameter value precision optimization for hole shape accuracy related indicators.

[0012] The laminated test plate combination needs to be fully covered and cross combined according to the product material and thickness information; The hole shape precision related indexes include, but are not limited to, hole roundness, hole nest coaxiality, dimple size precision, and burr height of the attached layer. The process parameter optimization test strategy includes, but is not limited to, single factor test, orthogonal test, and response surface optimization test. Preferably, the process strategy is called according to the cumulative information in step 7, including but not limited to the position information of each hole site, manufacturing index, and working condition information, and the appropriate process scheme is called based on the above information to sequentially complete the hole making.

[0013] Beneficial effects: For the problem of low matching degree of hole making process strategy under complex production working conditions of products in the field of aircraft assembly hole making, the present application provides a full-process process verification method for aircraft assembly hole making based on product structure characteristics. The method takes product structure characteristics as the origin, takes the local features of each hole site as the test density, and performs multi-level tests according to the categories of manufacturing indexes to complete the full-process verification of various manufacturing indexes. The method can more comprehensively identify complex problems after batch production of products, more fully verify the extreme working conditions in production, and more accurately customize process schemes. It is a process verification method with high accuracy, strong adaptability, and more systematic. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a flowchart of a process verification method for aircraft assembly hole making based on product structure characteristics; Figure 2 It is a hole site structure of a product partial pre-assembly area connecting fastener; Figure 3 It is a hole making station layout and hole site distribution diagram of an aircraft assembly; Figure 4 It is a structural model diagram of a test platform.

[0015] Numbering in the figure: 1, pre-connection hole site; 2, hole to be made; 3, double-sided edge strip hole making; 4, single-sided edge strip hole making; 5, hole making product; 6, hole making site; 7, end moving carrier; 8, end effector; 9, No. 001 hole making site; 10, No. 002 hole making site; 11, No. 003 hole making site; 12, No. 004 hole making site; 13, test tooling rack; 14, test flat plate; 15, testable area of test bench. DETAILED DESCRIPTION

[0016] The embodiments of the present application will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0017] The embodiment of the application provides an aircraft assembly hole forming process verification method based on product structure characteristics, comprising: Step 1: presetting a pre-assembly scheme based on product structure characteristics, adjusting the connection mode and connection spacing of pre-connected fasteners to ensure the overall stability after pre-assembly; Step 2: reasonably selecting a pre-connected fastener identification scheme based on the material category of the component to be assembled; Step 3: formulating an identification track of the pre-connected fastener based on the path optimization principle, and completing positioning of the product structure form in a global coordinate system; Step 4: determining the manufacturing indicators of each hole based on the aircraft assembly hole forming process correlation parameters; Step 5: presetting a test condition based on the manufacturing indicators of a certain hole, so that the current test condition is equivalent to the product condition; Step 6: performing step-by-step optimization on the hole forming process parameter domain based on the test board test, migrating the optimization results to the product hole forming, and completing the process parameter formulation; Step 7: calling the process strategy according to the manufacturing indicators and process parameters of each hole, and completing the hole forming of the complete hole profile.

[0018] The pre-assembly scheme of the product in step 1 comprises a single-row hole pre-assembly connection scheme and a double-row hole pre-assembly connection scheme: The single-row hole pre-assembly connection principle is to pre-connect according to a fixed hole spacing, and the proportion of the pre-connected fastener is not greater than 1 / 10 of the total hole quantity; The double-row hole pre-assembly connection principle is to diagonally arrange two temporary connection fasteners, and the proportion of the temporary connection fastener is not greater than 30% to 40% of the total hole quantity; The pre-connected fastener identification scheme in step 2 comprises but is not limited to image visual identification technology, magnetic induction identification technology and ultrasonic wave identification technology; The identification track of the pre-connected fastener in step 3 comprises but is not limited to taking an identification reference mark as a starting point and identifying according to an arch-shaped route or a back-shaped route; The identification object comprises the features and shapes of different fastener heads, holes and pockets, and is not limited to a "single" slot, a "cross" slot, a circle, an internal hexagon and an external hexagon; The positioning of the product structure form in the global coordinate system based on the coordinates of the reference mark in step 3 comprises: Grouping the reference marks in a region, linearly interpolating the coordinates of the reference marks in the same group based on the reference mark identification result in the product coordinate system; According to the number of holes to be formed in the reference mark spacing, the corresponding coordinates are uniformly distributed and allocated to complete the positioning of each hole to be formed; The aircraft assembly hole forming process correlation parameters in step 4 comprise but are not limited to: Hole spacing tolerance x1, hole row spacing tolerance x2, hole edge spacing tolerance x3, target hole diameter d, target counterbore diameter D, target counterbore depth H, target hole perpendicularity tolerance a, inner wall roughness R, entrance and exit burr height h; Step 41, No. 001 hole, manufacturing index requirements Hole spacing tolerance x1 = 0.5mm, hole row spacing tolerance x2 = 0.5mm, hole edge spacing tolerance x3 = 0.2mm, target hole diameter d = 6±0.02mm, target counterbore diameter D = 12±0.03mm, target hole perpendicularity tolerance a = 90°±0.5°; Step 42, No. 002 hole, manufacturing index requirements Hole spacing tolerance x1 = 0.5mm, hole row spacing tolerance x2 = 0.5mm, hole edge spacing tolerance x3 = 0.2mm, target hole diameter d = 8±0.02mm, target counterbore diameter D = 16±0.03mm, target hole perpendicularity tolerance a = 90°±0.5°; Step 43, according to the specific index requirements of each hole, in turn calibration.

[0019] The pre-set test working condition and product working condition equivalent method in step 5 comprises: Step 51, identify the local characteristics of each hole site, including but not limited to local curvature, local stiffness.

[0020] Step 52, facing the test object, by adjusting the thickness and size of the test plate, the local stiffness under each structure is calibrated; Step 53, facing the test object, by selecting test pieces with different curvatures, the local curvature of different experimental objects is calibrated; Step 53, match the test objects with the same local curvature and local stiffness as the characteristics of a certain hole site in the product as equivalent groups under the test working condition; Step 54, repeat the above steps until all product hole working conditions and test working conditions are equivalent.

[0021] The test plate test in step 6 comprises the following two sub-test steps: Step 61, single-layer test plate test: according to the material category corresponding to a certain hole site of the product, process test is carried out to obtain a process scheme for adapting to the material characteristics, until all hole sites are covered.

[0022] Step 62, laminated test plate test: according to the material combination corresponding to a certain hole site of the product, process test is carried out to obtain a process scheme for adapting to the structure characteristics, until all hole sites are covered.

[0023] The step-by-step optimization scheme for hole processing parameter domain in the test plate test comprises the following sub-steps: Step 611, single-layer test board test includes but is not limited to compression damage threshold calibration test, process parameter domain optimization test for hole size related indicators; Among them, the compression damage threshold calibration test is to obtain the maximum compression force threshold applied in the hole forming process without damaging the surface integrity of the product; Among them, the process parameter domain optimization test for hole size related indicators is to obtain the preliminary optimization of process parameters under the premise of meeting part of the manufacturing indicators, and to obtain the boundary of the allowable value; Among them, the hole size related indicators include but are not limited to hole diameter accuracy, surface quality, entrance and exit damage; Step 612, laminated test board test further restores the product structure characteristics, and further verifies the process parameter value precision optimization for the hole shape accuracy related indicators.

[0024] Among them, the laminated test board combination needs to be fully covered and combined according to the product material and thickness information; Among them, the hole shape accuracy related indicators include but are not limited to hole roundness, hole coaxiality, dimming size accuracy, and bonding layer burr height; Among them, the process parameter optimization test strategy includes but is not limited to single factor test, orthogonal test, and response surface optimization test; The step 7 calls the process strategy according to the cumulative information, including but not limited to the position information of each hole, the manufacturing indicators, and the working condition information, and the adaptive process scheme is called based on the above information to complete the hole forming in turn.

[0025] Figure 1A flowchart of an aircraft assembly hole-making process verification method based on product structure characteristics is provided for the embodiments of the present disclosure. In order to meet the hole-making requirements of different structure types of objects to be assembled, verification of process adaptability needs to be carried out from multiple angles such as product pre-assembly scheme, hole-making process scheme, etc. First, a pre-assembly scheme is formulated according to the object to be drilled, including methods such as tensioner wrapping constraint, shape-following clamp plate constraint, etc. to pre-assemble the structures to be connected according to the assembly state; a hole-making positioning scheme is formulated according to the pre-assembly scheme to position the hole-making profile of the product to be drilled in the global coordinate system; a pre-connection fastener identification trajectory scheme is formulated according to the structure characteristics of the product to be drilled, and the identification trajectory is formulated according to the principles of proximity, obstacle avoidance, and no U-turn, thereby completing the identification of the pre-assembly state of the product. Second, the working condition characteristics of each hole-making position in the pre-assembly state of the product are identified one by one, including the local curvature, local stiffness, and target size of each hole-making position. Finally, a test environment is formulated according to the identification information of the hole-making working condition, and the test working condition is equivalent to the product hole-making working condition. The process test of the hole-making parameters is completed in a specific equivalent test environment, and the optimal test of the variables such as spindle speed, pressing force, spindle feed speed, lubrication flow, and pecking depth is completed. This includes single-layer test and stacked test plate test: single-layer test plate test is used to verify the manufacturing indicators related to the size accuracy of the center through hole, while the stacked test plate test is used to verify the manufacturing indicators related to the size accuracy of the countersunk hole, as well as related shape accuracy indicators; thereby completing the formulation of the process scheme and completing the whole-process process verification before the product enters the line.

[0026] Figure 2 A hole structure of a product partial pre-assembly area connection fastener is provided for the embodiments of the present disclosure. The structure is connected to other components as the connecting edge strip of the cavity structure, including: 1, pre-connection hole; 2, hole to be drilled; 3, double-sided edge strip hole; 4, single-sided edge strip hole; wherein the red hole represents the pre-connection fastener installed in the hole, and the hole not marked in red is the hole to be drilled.

[0027] The product structure includes two connection schemes of single-sided edge strip pre-connection and double-sided edge strip pre-connection. The single-sided edge strip pre-connection fastener is arranged at an interval of 200mm-300mm to control the proportion of temporary connection fasteners to the total amount of holes to be drilled as much as possible; the double-sided edge strip adopts a double-sided diagonal alternating scheme to control the proportion of temporary connection fasteners to the total amount of holes to be drilled as much as possible. 30%-40%. The pre-connection fastener is used to realize the pre-assembly of the stacked structure of the product to be drilled, so as to prepare for drilling in the pre-assembly posture; after this step, the drilling station is entered for drilling.

[0028] Figure 3The aircraft assembly hole station layout and hole distribution map provided by the embodiment of the present disclosure comprises: 5, a hole making product; 6, a hole making station; 7, an end moving carrier; 8, an end effector; 9, No. 001 hole making station; 10, No. 002 hole making station; 11, No. 003 hole making station; 12, No. 004 hole making station.

[0029] The station is a product hole making station, that is, after the connection components of the product complete component pre-assembly, the product hole making area is subjected to hole making by the hole making equipment. First, the hole making end effector identifies the local working condition of each hole making station in the hole making product in a specific posture, taking No. 001 hole making station as an example, sequentially identifying until all hole making stations are fully covered; second, according to the hole making station information, the hole making stations with similar working conditions are regarded as equivalent areas, and the test working conditions are customized one by one according to the information.

[0030] Figure 4 The structure model diagram of the test platform provided by the embodiment of the present disclosure is a simple test platform built to restore and simulate the local working condition of the product, comprising: 13, a test tool frame; 14, a test flat plate; 15, a test table testable area.

[0031] Exemplarily, the manufacturing indexes of No. 001-020 hole making stations require hole spacing tolerance x1=0.5mm, hole row spacing tolerance x2=0.5mm, hole edge spacing tolerance x3=0.2mm, target hole making diameter d=6±0.02mm, target dimple diameter D=12±0.03mm, target hole making perpendicularity tolerance α=90°±0.5°; the local working condition is three kinds of laminated materials, which are carbon fiber composite material, 7050 aluminum alloy and 2024 aluminum alloy; the curvature radius is 5000mm; and the local stiffness is 500N / mm.

[0032] The manufacturing indexes of No. 021-050 hole making stations require hole spacing tolerance x1=0.5mm, hole row spacing tolerance x2=0.5mm, hole edge spacing tolerance x3=0.2mm, target hole making diameter d=8±0.02mm, target dimple diameter D=16±0.03mm, target hole making perpendicularity tolerance α=90°±0.5°; the local working condition is two kinds of laminated materials, which are carbon fiber composite material and 7050 aluminum alloy; the curvature radius is 20000mm; and the local stiffness is 1000N / mm.

[0033] According to the hole site characteristic identification result, the hole sites No. 001-050 are divided into two characteristic groups, the No. 001-020 are group A, and the No. 021-050 are group B. According to the characteristic information of group A, the test working condition in the test tool holder is formulated, the test test plate in the test tool holder that meets the clamping size is selected, the material is consistent with the product working condition, that is, carbon fiber composite material, 7050 aluminum alloy, 2024 aluminum alloy, and the curvature is consistent with the product. The overall stiffness of the three-layer laminated material is detected, the thickness of the first and second test test plates is consistent with the product, and the thickness of the third test plate is adjusted to ensure that the thickness of the three-layer test plate is consistent with the product group A stiffness working condition. The combination of the test plate in this state is the equivalent test working condition of the product group A working condition, and the process parameter optimization test is carried out again under the working condition.

[0034] The process experiment is divided into single plate test and laminated test. The single plate test is to split three kinds of laminated materials, and sequentially carry out hole making test until the process parameter optimization is completed. According to the hole making size index d = 6 ± 0.02mm, hole making perpendicularity tolerance α = 90° ± 0.5°, the main shaft speed, the pressing force, the main shaft feed speed, the lubrication flow, the pecking depth and other variables are optimized one by one by single factor test, and the parameter interval meeting the above manufacturing index is obtained. The parameter optimization results of the carbon fiber composite test plate are: the allowable interval of the main shaft speed is [6000-8000rpm], the allowable interval of the lubrication flow is [10-15L / h], the allowable interval of the pressing force is [300-500N], the allowable interval of the main shaft feed speed is [100-300mm / min], and the allowable interval of the pecking depth is [0.5-2mm]; the parameter optimization results of the 7050 aluminum alloy test plate are: the allowable interval of the main shaft speed is [6500-8000rpm], the allowable interval of the lubrication flow is [10-30L / h], the allowable interval of the pressing force is [300-1000N], the allowable interval of the main shaft feed speed is [100-300mm / min], and the allowable interval of the pecking depth is [0.5-1mm]; the parameter optimization results of the 2024 aluminum alloy test plate are: the allowable interval of the main shaft speed is [4000-8000rpm], the allowable interval of the lubrication flow is [10-30L / h], the allowable interval of the pressing force is [300-1000N], the allowable interval of the main shaft feed speed is [100-300mm / min], and the allowable interval of the pecking depth is [0.5-1mm]; in summary, the process parameter allowable interval meeting the three kinds of materials is: the allowable interval of the main shaft speed is [6000-8000rpm], the allowable interval of the lubrication flow is [10-15L / h], the allowable interval of the pressing force is [300-500N], the allowable interval of the main shaft feed speed is [100-300mm / min], and the allowable interval of the pecking depth is [0.5-1mm]. The laminated test is to match different material thickness according to the stiffness calibration results of the three kinds of materials, and to carry out hole making test. According to the dimpling size index dimpling diameter D = 12 ± 0.03mm, hole center coaxiality ± 0.001mm, the main shaft speed, the pressing force, the main shaft feed speed, the lubrication flow, the pecking depth and other variables are comprehensively optimized according to table 1 by orthogonal test method, the variable values are shown in table 2, and the optimal parameter group meeting the above manufacturing index is obtained, that is, the main shaft speed is 6000rpm, the pressing force is 400N, the main shaft feed speed is 300mm / min, the lubrication flow is 10L / h, and the pecking depth is 1mm.

[0035] Table 1 Five-factor three-level orthogonal test table L18(3 5 )

[0036] Table 2 Test variable value table

[0037] Based on the above, the process parameters of the product hole profile in group A (No. 001-020 hole) are tested, and the process parameters of group B (No. 021-050 hole) are repeated to complete the selected experiment.

[0038] The above description shows and describes the preferred embodiments of the present application, as previously described, it should be understood that the present application is not limited to the forms disclosed herein, should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the inventive concept described herein, by the above teaching or related technical or knowledge. The modifications and changes made by those skilled in the art without departing from the spirit and scope of the present application shall be within the scope of the appended claims of the present application.

Claims

1. An aircraft assembly hole-making process verification method based on product structure characteristics, characterized in that, The method comprises the following steps: Step 1: presetting a pre-assembly scheme based on product structure features, adjusting the connection mode and connection spacing of pre-connected fasteners to ensure the stability of the product structure after pre-assembly; Step 2: reasonably selecting a pre-assembly fastener identification scheme based on the material category of the component to be assembled; Step 3: formulating an identification trajectory of the pre-assembly fastener based on the path optimization principle, and completing the positioning of the product structure form in the global coordinate system; Step 4: determining the manufacturing indicators of each hole based on the associated parameters of the aircraft assembly hole forming process; Step 5: presetting a test working condition based on the manufacturing indicators of a certain hole, so that the preset test working condition is equivalent to the product working condition; Step 6: performing step-by-step optimization of the hole forming process parameter domain based on the test plate test, and migrating the optimization results to the product hole forming to complete the process parameter formulation; Step 7: calling the process strategy according to the manufacturing indicators and process parameters of each hole to complete the hole forming of the complete hole surface.

2. The method of claim 1, wherein, The pre-assembly scheme in step 1 includes a single-row hole pre-assembly connection scheme and a double-row hole pre-assembly connection scheme: The single-row hole pre-assembly connection scheme is to pre-connect according to a fixed hole spacing, and the proportion of pre-connected fasteners is not more than 1 / 10 of the total number of holes. The double-row hole pre-assembly connection scheme is to diagonally arrange two temporary connection fasteners, and the proportion of temporary connection fasteners is not more than 30%-40% of the total number of holes.

3. The method of claim 1, wherein, The identification scheme of the pre-assembly fastener in step 2 is an image visual identification technology, a magnetic induction identification technology or an ultrasonic wave identification technology, which includes: The visual identification technology is suitable for detection conditions where the material of the outer surface of the component to be assembled is non-metallic and has poor electrical conductivity. The magnetic induction identification technology is suitable for detection conditions where the material of the outer surface of the component to be assembled is metallic, has strong electrical conductivity and poor optical properties with strong light reflection characteristics. The ultrasonic wave identification technology is suitable for detection conditions where the material of the outer surface of the component to be assembled is metallic or non-metallic and has a large thickness.

4. The method of claim 1, wherein, In step 3, the identification trajectory of the pre-assembly fastener is formulated, specifically: taking a reference nail as the starting point, and identifying according to an arch-shaped route or a back-shaped route; The identification objects include the features and shapes of different fastener heads, holes and pockets, including "single" grooves, "cross" grooves, circles, internal hexagons and external hexagons.

5. The method of claim 4, wherein, In step 3, the positioning of the product structure form in the global coordinate system is completed based on the coordinates of the reference nail, which includes: Grouping the reference nails by regions, linearly interpolating the coordinates of the reference nails in the same group based on the identification results of the reference nails in the product coordinate system; According to the number of holes to be formed within the spacing of the reference nails, the corresponding coordinates are uniformly distributed to complete the positioning of each hole to be formed.

6. The method of claim 5, wherein, The aircraft assembly hole forming process associated parameters in step 4 at least include: Hole spacing tolerance x1, hole row spacing tolerance x2, hole edge spacing tolerance x3, target hole diameter d, target counterbore diameter D, target counterbore depth H, target hole perpendicularity tolerance α, inner wall roughness R, and entrance and exit burr height h. Step 41, No. 001 hole site, manufacturing index requires hole spacing tolerance x1 = 0.5mm, hole spacing tolerance x2 = 0.5mm, hole spacing tolerance x3 = 0.2mm, target hole diameter d = 6 ± 0.02mm, target dimple diameter D = 12 ± 0.03mm, target hole perpendicularity tolerance α = 90° ± 0.5°; Step 42, No. 002 hole site, manufacturing index requires hole spacing tolerance x1 = 0.5mm, hole spacing tolerance x2 = 0.5mm, hole spacing tolerance x3 = 0.2mm, target hole diameter d = 8 ± 0.02mm, target dimple diameter D = 16 ± 0.03mm, target hole perpendicularity tolerance α = 90° ± 0.5°; Step 43, according to the specific manufacturing index requirements of each hole site, in turn calibration.

7. The method of verifying a drilling process for aircraft assembly based on product structure characteristics of claim 6, wherein, The preset test working condition equivalent method in step 5 comprises: Step 51, identify the local characteristics of each hole site, at least including local curvature, local stiffness; Step 52, facing the test object, by adjusting the thickness and size of the test plate, the local stiffness under each structure is calibrated; Step 53, facing the test object, by selecting test pieces with different curvatures, the local curvature of different test objects is calibrated; Step 53, match the local curvature and local stiffness under the test working condition with the test object whose characteristics of a hole site of the product are consistent as an equivalent group; Step 54, repeat the above steps until all product hole site working conditions and test working conditions are equivalent.

8. The method of claim 7, wherein, The test plate test in step 6 comprises: Step 61, single-layer test plate test: according to the material category corresponding to a hole site of the product, process test is carried out to obtain a process scheme for adapting to material characteristics until all hole sites are covered. Step 62, laminated test plate test: according to the material combination corresponding to a hole site of the product, process test is carried out to obtain a process scheme for adapting to structural characteristics until all hole sites are covered.

9. The method of claim 8, wherein, The step-by-step optimization of the hole forming process parameter domain in the test plate test comprises the following sub-steps: Step 611, single-layer test plate test at least includes: compression damage threshold calibration test, process parameter domain optimization test for hole size related indicators; Wherein the compression damage threshold calibration test is to obtain the maximum compression force threshold applied in the hole forming process; Wherein the process parameter domain optimization test for hole size related indicators is to obtain the boundary of the allowable value by preliminary optimization of the process parameters under the premise of meeting part of the manufacturing index; Wherein the hole size related indicators at least include: hole diameter accuracy, surface quality, entrance and exit damage; Step 612, laminated test plate test verifies the process parameter value by supplementing the verification of the hole shape accuracy related indicators through the reduction of the product structure characteristics; Wherein the laminated test plate combination needs to be fully covered by cross combination according to the product material and thickness information; Wherein the hole shape accuracy related indicators at least include: hole roundness, hole dimple coaxiality, dimple size accuracy, and bonding layer burr height; Wherein the process parameter optimization test strategy is: single factor test, orthogonal test or response surface optimization test.

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