A method for detecting catheter fit, coaxiality, and deviation based on 3D scanning technology

Abstract

This invention belongs to the field of aircraft duct assembly and inspection technology, and specifically relates to a method for detecting the fit, coaxiality, and deviation between ducts and piping accessories during assembly. Specifically, it is a method for detecting the fit, coaxiality, and deviation of ducts based on three-dimensional scanning technology. This invention enables quantitative detection of fit, coaxiality, and deviation during aircraft duct assembly, improving detection accuracy and efficiency, and ensuring high-quality assembly of aircraft ducts.

Description

Technical Field

[0001] This invention belongs to the field of aircraft duct assembly and inspection technology, and specifically relates to a method for detecting the fit, coaxiality, and deviation between ducts and pipeline accessories during the assembly process. Specifically, it is a method for detecting the fit, coaxiality, and deviation of ducts based on three-dimensional scanning technology. Background Technology

[0002] During the assembly of aircraft flared conduits, to achieve a good seal, it is necessary to check the fit, coaxiality, and misalignment during assembly. These three indicators significantly affect the size of the annular sealing surface of the flared conduit, thus affecting the degree of sealing. The conduit fit indicators are as follows: Figure 1 As shown, the catheter coaxiality index is as follows: Figure 2 As shown, the catheter deviation index is as follows: Figure 3 As shown.

[0003] Currently, in the aviation industry, the inspection of duct fit is done manually by inserting a metal feeler gauge into the mating area between the duct and the hydraulic accessory. This method is highly susceptible to human error, cumbersome, and carries the risk of scratching the tapered surface of the flared duct during measurement, posing a safety hazard. Furthermore, the inspection of duct coaxiality and misalignment is currently only qualitative, lacking the ability to perform quantitative testing according to relevant technical standards.

[0004] Therefore, how to quickly and quantitatively detect the fit, coaxiality, and skewness of aircraft hydraulic system conduits, thereby improving the sealing and safety of aircraft hydraulic system conduits, is a technical problem that urgently needs to be solved in the field of conduit assembly and inspection. Summary of the Invention

[0005] To improve the assembly quality of aircraft ducts and achieve quantitative detection of duct fit, coaxiality, and deviation, while improving detection efficiency and accuracy, this invention provides a method for detecting duct fit, coaxiality, and deviation based on three-dimensional scanning technology.

[0006] The technical solution of the present invention is as follows:

[0007] The method for detecting catheter fit, coaxiality, and deviation based on three-dimensional scanning technology includes the following specific steps:

[0008] S01: Deploy an industrial photography camera system

[0009] Based on the assembly location of the duct on the aircraft structure, the industrial camera is arranged according to the actual situation; during the arrangement, the industrial camera completely covers the assembly area of ​​the duct, and ensures that there are no extra obstacles blocking the path of the optical tracking scanner to receive data during the scanning process; ensure that the industrial camera can quickly, completely and accurately receive the scanned images.

[0010] S02: Data system connection and initialization

[0011] Connect the data transmission cable of the industrial camera and the data cable of the optical tracking scanner to the corresponding interfaces on the high-performance data processing workstation; start the industrial camera and the optical tracking scanner to complete the automatic calibration.

[0012] S03: Initialize the optical tracking scanner

[0013] An optical tracking scanner is used to perform an initial scan of the scanning area. Based on the received initial data, a high-performance data processing workstation establishes the system's relative coordinate system (x, y, z).

[0014] S04: Scan the conduit and piping accessories after assembly.

[0015] An optical tracking scanner is used to scan the area of ​​the catheter assembly that needs to be inspected, and to perform a detailed scan of the catheter and tubing accessories.

[0016] S05: High-performance data processing workstations perform data analysis.

[0017] Based on the scanned data of the conduit and tubing accessories, the surface equation F1(x,y,z)=0 and the axis equation L1 of the conduit cone are calculated, and the surface equation F2(x,y,z)=0 and the axis equation L2 of the tubing accessory cone are calculated.

[0018] S06: Calculate the catheter's fit, coaxiality, and deviation data.

[0019] S06.1: Calculate the fit between the conduit and tubing fittings in each state (ε1, ε2, ε3, ... ε i Using this data, the final fit data Δ1 is calculated.

[0020] S06.2: The high-performance data processing workstation calculates the duct axis direction vector. Direction vector relative to the axis of the pipe fitting

[0021] S06.3: If a high-performance data processing workstation calculates the duct axis direction vector Vector of the axis of the pipeline fitting When the vectors are collinear, the intersection point s between the duct axis L1 and the reference vertical plane y=0, and the intersection point l between the duct accessory axis L2 and the reference vertical plane y=0 are used as data to calculate the final coaxiality data Δ2.

[0022] S06.4: If a high-performance data processing workstation calculates the duct axis direction vector Direction vector relative to the axis of the pipe fitting When the vectors are non-collinear, the direction vectors are used. and direction vector Based on the basic data, the final skewness data Δ3 is calculated.

[0023] S07: Evaluate the assembly quality of the catheter

[0024] After completing step S06, the high-performance data processing workstation evaluates the assembly quality of the catheter according to the calculated catheter fit Δ1, coaxiality Δ2, and deviation Δ3, and provides a corresponding technical report.

[0025] The high-performance data processing workstation calculates catheter fit, coaxiality, and deviation using the following methods:

[0026] (1) Establish the relative coordinate system (x,y,z) of the optical three-dimensional scanning measurement system;

[0027] (2) Calculate the surface equation and axis equation of the conical duct surface:

[0028] Conical surface: F1(x,y,z)=0

[0029] Axis:

[0030] Let (x1, y1, z1) be the direction vector of the catheter axis; (x1, y1, z1) are the coordinates of reference point a on the L1 axis.

[0031] (3) Calculate the surface equation and axis equation of the conical surface of the pipeline fitting:

[0032] Conical surface: F2(x,y,z)=0

[0033] Axis:

[0034] Let (x2, y2, z2) be the direction vector of the pipeline accessory axis; (x2, y2, z2) are the coordinates of reference point b on the L2 axis.

[0035] (4) Calculate the fit Δ1 between the conduit and pipe fittings:

[0036] (4.1) Calculate the plane obtained by rotating the reference vertical plane y=0 by 0.1° (range 0°~180°) around the duct axis each time:

[0037] P n (x,y,z)=0

[0038] (4.2) Calculation of plane P n The plane perpendicular to (x,y,z)=0:

[0039] Q n (x,y,z)=0

[0040] (4.3) Calculate the curvature of the conical surface of the duct and the plane P. n The line of intersection between (x, y, z) = 0 and

[0041] f1(F1(x,y,z)=0,P n (x,y,z)=0)

[0042]

[0043]

[0044] Where f1 is the surface used to calculate the conical surface of the duct and the plane P n The function of the intersection line of (x,y,z)=0; It is a straight line Reference points on the surface Its direction vector; It is a straight line Reference points on the surface Its direction vector;

[0045] (4.4) Calculate the curvature of the conical surface of the pipeline fitting and the plane P. n The line of intersection between (x, y, z) = 0 and

[0046] g1(F2(x,y,z)=0,P n (x,y,z)=0)

[0047]

[0048]

[0049] Where g1 is the surface of the conical surface of the calculated pipeline accessory and the plane P n The function of the intersection line of (x,y,z)=0; It is a straight line Reference points on the surface Its direction vector; It is a straight line Reference points on the surface Its direction vector;

[0050] (4.5) Calculate the intersection line and With plane Q n The intersection point between (x, y, z) = 0 and

[0051]

[0052]

[0053] Where f2 is the line to be calculated. and With plane Q n The function representing the intersection points of (x, y, z) = 0; k i and k i+1 Represents a straight line and The corresponding intersection point;

[0054] (4.6) Calculate the intersection line and With plane Q n The intersection point between (x, y, z) = 0 and

[0055]

[0056]

[0057] Where g2 is the intersection line calculated. and With plane Q n The function representing the intersection points of (x, y, z) = 0; p i and p i+1 Representative intersection line and The corresponding intersection point;

[0058] (4.7) Calculate the fit ε between the conduit and pipe fittings after each deflection of the reference vertical plane y=0. i :

[0059]

[0060]

[0061] Where τ is the calculation coefficient, τ=1 / sin(θ), and θ is the cone degree of the flared catheter;

[0062]

[0063] (4.8) Calculate the final fit Δ1 between the conduit and tubing fittings:

[0064] Δ1=MAX(ε1,ε2,ε3,…ε i )

[0065] (5) Determine the direction vector of the catheter axis Direction vector relative to the axis of the pipe fitting Are they collinear vectors?

[0066]

[0067] Where α is a system parameter used for discrimination. and Are they collinear vectors? When α ≠ 0, and They are collinear vectors; when α = 0, and They are non-collinear vectors;

[0068] (6) When the catheter axis direction vector Direction vector relative to the axis of the pipe fitting When the vectors are collinear, calculate the coaxiality Δ2 between the conduit and pipe fittings:

[0069] (6.1) Calculate the intersection point s(x) between the catheter axis L1 and the reference vertical plane y = 0. s ,y s ,z s ).

[0070]

[0071] Where f3 is a function for calculating the intersection point between the duct axis L1 and the reference vertical plane y = 0;

[0072] (6.2) Calculate the intersection point l(x) between the pipeline fitting axis L2 and the reference vertical plane y = 0. l ,y l ,z l ).

[0073]

[0074] Where g3 is a function for calculating the intersection point between the pipeline accessory axis L2 and the reference vertical plane y = 0;

[0075] (6.3) Calculate the coaxiality Δ2 between the conduit and piping fittings:

[0076]

[0077] (7) When the catheter axis direction vector Direction vector relative to the axis of the pipe fitting When the vectors are non-collinear, calculate the skewness Δ3 between the conduit and pipe fittings:

[0078]

[0079] The beneficial effects of this invention are:

[0080] (1) This invention adopts a unique design concept and formulates a set of operating algorithms for detecting catheter fit, coaxiality and deviation based on three-dimensional scanning technology, which can realize automatic evaluation of catheter assembly quality.

[0081] (2) The optical three-dimensional scanning measurement system involved in this invention can achieve high-precision and rapid scanning of catheters and tubing accessories, avoiding complicated manual operations and damage to the catheters that may be caused during manual inspection.

[0082] (3) The present invention provides a method for detecting the fitting degree, coaxiality and deviation of a catheter using three-dimensional scanning technology, which can realize the quantitative detection of fitting degree Δ1, coaxiality Δ2 and deviation Δ3 during aircraft catheter assembly, and improves the detection accuracy and efficiency, ensuring high-quality assembly of aircraft catheters. Attached Figure Description

[0083] Figure 1 This is a schematic diagram of catheter fit index.

[0084] Figure 2 This is a schematic diagram of the catheter coaxiality index.

[0085] Figure 3 This is a schematic diagram of the catheter deviation index.

[0086] Figure 4 This is a schematic diagram of the catheter fitting, coaxiality, and deviation detection method based on three-dimensional scanning technology of the present invention. Detailed Implementation

[0087] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0088] The basic process of the catheter fitting, coaxiality, and deviation detection method based on three-dimensional scanning technology of the present invention is as follows: Figure 4As shown. The equipment used includes an optical 3D scanning measurement system and a high-performance data processing workstation. The optical 3D scanning measurement system consists of an optical tracking scanner and an industrial camera. The optical tracking scanner is used to scan conduits and related accessories, while the industrial camera is used to acquire images scanned by the optical tracking scanner. The high-performance data processing workstation is a data analysis and processing module that analyzes and processes the images acquired by the industrial camera, extracts the main information of the scanned conduits and related accessories, and calculates data such as conduit fit, coaxiality, and deviation as required. Based on the measurement position of the optical 3D scanning measurement system, the high-performance data processing workstation establishes a relative coordinate system, analyzes and calculates the surface and axial parameters of the scanned conduits and pipe accessories, and uses this as the basis for calculating the fit, coaxiality, and deviation of the conduits after assembly.

[0089] The specific implementation method is as follows:

[0090] S01: Deploy an industrial photography camera system

[0091] Based on the assembly location of the duct on the aircraft structure, the industrial camera is arranged according to the actual situation. During the arrangement, the industrial camera can completely cover the assembly area of ​​the duct and ensure that there are no extra obstacles blocking the path of the optical tracking scanner during the scanning process. It also ensures that the industrial camera can quickly, completely and accurately receive the scanned images.

[0092] S02: Data system connection and initialization

[0093] Connect the data transmission cable of the industrial camera and the data cable of the optical tracking scanner to the corresponding interfaces on the high-performance data processing workstation; start the industrial camera and the optical tracking scanner to complete the automatic calibration.

[0094] S03: Initialize the optical tracking scanner

[0095] The scanning area is initially scanned for 5 seconds using an optical tracking scanner. Based on the received initial data, the high-performance data processing workstation establishes the system's relative coordinate system (x, y, z).

[0096] S04: Scan the conduit and piping accessories after assembly.

[0097] The area of ​​the catheter assembly to be inspected is scanned using a handheld optical tracking scanner. The catheter and tubing accessories are scanned in detail for 10-20 seconds. During the scanning process, two people are required: one person is responsible for the scanning work, and the other person is responsible for observing whether the data scanned by the high-performance data processing workstation is complete.

[0098] S05: High-performance data processing workstations perform data analysis.

[0099] Based on the scanned data of the conduit and tubing accessories, the surface equation F1(x,y,z)=0 and the axis equation L1 of the conduit cone are calculated, and the surface equation F2(x,y,z)=0 and the axis equation L2 of the tubing accessory cone are calculated.

[0100] S06: Calculate the catheter's fit, coaxiality, and deviation data.

[0101] S06.1: Calculate the fit between the conduit and tubing fittings in each state (ε1, ε2, ε3, ... ε i Using this data, the final fit data Δ1 is calculated.

[0102] S06.2: The high-performance data processing workstation calculates the duct axis direction vector. Direction vector relative to the axis of the pipe fitting

[0103] S06.3: If a high-performance data processing workstation calculates the duct axis direction vector Vector of the axis of the pipeline fitting When the vectors are collinear (i.e., α≠0), the intersection point s between the duct axis L1 and the reference vertical plane y=0, and the intersection point l between the pipe fitting axis L2 and the reference vertical plane y=0 are used. Based on this data, the final coaxiality data Δ2 is calculated.

[0104] S06.4: If a high-performance data processing workstation calculates the duct axis direction vector Direction vector relative to the axis of the pipe fitting When the vectors are non-collinear (i.e., α = 0), the direction vectors are... and direction vector Based on the basic data, the final skewness data Δ3 is calculated.

[0105] S07: Evaluate the assembly quality of the catheter

[0106] After completing step S06, the high-performance data processing workstation evaluates the assembly quality of the catheter according to the calculated catheter fit Δ1, coaxiality Δ2, and deviation Δ3, and provides a corresponding technical report.

Claims

1. A method for detecting catheter fit, coaxiality, and deviation based on three-dimensional scanning technology, characterized in that, The specific steps are as follows: S01: Deploy an industrial photography camera system Based on the assembly location of the duct on the aircraft structure, the industrial camera is arranged according to the actual situation; during the arrangement, the industrial camera completely covers the assembly area of ​​the duct, and ensures that there are no extra obstacles blocking the path of the optical tracking scanner to receive data during the scanning process; ensure that the industrial camera receives the scanned images completely and accurately. S02: Data system connection and initialization Connect the data transmission cable of the industrial camera and the data cable of the optical tracking scanner to the corresponding interfaces on the high-performance data processing workstation; start the industrial camera and the optical tracking scanner to complete the automatic calibration. S03: Initialize the optical tracking scanner An optical tracking scanner is used to perform an initial scan of the scanning area. Based on the received initial data, a high-performance data processing workstation establishes a system relative coordinate system (x, y, z). S04: Scan the conduit and piping accessories after assembly. An optical tracking scanner is used to scan the area of ​​the catheter assembly that needs to be inspected, and to perform a detailed scan of the catheter and tubing accessories. S05: High-performance data processing workstations perform data analysis. Based on the scanned data of the conduit and tubing accessories, calculate the surface equation F1(x,y,z)=0 and the axis equation L1 of the conduit cone surface, and the surface equation F2(x,y,z)=0 and the axis equation L2 of the tubing accessory cone surface. S06: Calculate the catheter's fit, coaxiality, and deviation data. S06.1: Calculate the fit between the conduit and tubing fittings in each state (ε1, ε2, ε3, ... ε i Using this data, the final fit data Δ1 is calculated. S06.2: The high-performance data processing workstation calculates the duct axis direction vector. Direction vector relative to the axis of the pipe fitting S06.3: If a high-performance data processing workstation calculates the duct axis direction vector... Vector of the axis of the pipeline fitting When they are collinear vectors, the intersection point s between the duct axis L1 and the reference vertical plane y=0, and the intersection point l between the duct accessory axis L2 and the reference vertical plane y=0; and using these data, the final coaxiality data Δ2 is calculated. S06.4: If a high-performance data processing workstation calculates the duct axis direction vector Direction vector relative to the axis of the pipe fitting When the vectors are non-collinear, the direction vectors are used. and direction vector Based on the basic data, the final skewness data Δ3 is calculated; S07: Evaluate the assembly quality of the catheter After completing step S06, the high-performance data processing workstation evaluates the assembly quality of the catheter according to the calculated catheter fit Δ1, coaxiality Δ2, and deviation Δ3, and provides a corresponding technical report.

2. The method for detecting catheter fit, coaxiality, and deviation based on three-dimensional scanning technology according to claim 1, characterized in that, The high-performance data processing workstation is a data analysis and processing module that analyzes and processes the images captured by the industrial camera, extracts the main information of the scanned catheters and related accessories, and calculates data such as the fit, coaxiality, and deviation of the catheters according to requirements.

3. The method for detecting catheter fit, coaxiality, and deviation based on three-dimensional scanning technology according to claim 1, characterized in that, In step S04, the scanning process requires two people: one to be responsible for the scanning work and the other to observe whether the data scanned by the high-performance data processing workstation is complete.

4. The method for detecting catheter fit, coaxiality, and deviation based on three-dimensional scanning technology according to claim 1, characterized in that, The high-performance data processing workstation calculates catheter fit, coaxiality, and deviation using the following methods: (1) Establish the relative coordinate system (x,y,z) of the optical three-dimensional scanning measurement system; (2) Calculate the surface equation and axis equation of the conical duct surface: Conical surface: F1(x,y,z)=0 Axis: Let (x1, y1, z1) be the direction vector of the catheter axis; (x1, y1, z1) are the coordinates of reference point a on the L1 axis. (3) Calculate the surface equation and axis equation of the conical surface of the pipeline fitting: Conical surface: F2(x,y,z)=0 Axis: Let (x2, y2, z2) be the direction vector of the pipeline accessory axis; (x2, y2, z2) are the coordinates of reference point b on the L2 axis. (4) Calculate the fit Δ1 between the conduit and pipe fittings: (4.1) Calculate the plane obtained by rotating the reference vertical plane y=0 by 0.1° each time around the duct axis: P n (x,y,z)=0 (4.2) Calculation of plane P n The plane perpendicular to (x,y,z)=0: Q n (x,y,z)=0 (4.3) Calculate the curvature of the conical surface of the duct and the plane P. n The line of intersection between (x, y, z) = 0 and f1(F1(x,y,z)=0,P n (x,y,z)=0) Where f1 is the surface used to calculate the conical surface of the duct and the plane P n A function of the intersection line of (x,y,z)=0; It is a straight line Reference points on the surface Its direction vector; It is a straight line Reference points on the surface Its direction vector; (4.4) Calculate the curvature of the conical surface of the pipeline fitting and the plane P. n The line of intersection between (x, y, z) = 0 and g1(F2(x,y,z)=0,P n (x,y,z)=0) Where g1 is the surface of the conical surface of the calculated pipeline accessory and the plane P n A function of the intersection line of (x,y,z)=0; It is a straight line Reference points on the surface Its direction vector; It is a straight line Reference points on the surface Its direction vector; (4.5) Calculate the intersection line and With plane Q n The intersection point between (x, y, z) = 0 and Where f2 is the line to be calculated. and With plane Q n The function representing the intersection points of (x, y, z) = 0; k i and k i+1 Represents a straight line and The corresponding intersection point; (4.6) Calculate the intersection line and With plane Q n The intersection point between (x, y, z) = 0 and Where g2 is the calculated intersection line L pi and With plane Q n The function representing the intersection points of (x, y, z) = 0; p i and p i+1 Represents the intersection line L pi and The corresponding intersection point; (4.7) Calculate the fit ε between the conduit and pipe fittings after each deflection of the reference vertical plane y=0. i : Where τ is the calculation coefficient, τ=1 / sin(θ), and θ is the cone degree of the flared catheter; (4.8) Calculate the final fit Δ1 between the conduit and tubing fittings: Δ1=MAX(ε1,ε2,ε3,……ε i ) (5) Determine the direction vector of the catheter axis Direction vector relative to the axis of the pipe fitting Are they collinear vectors? Where α is a system parameter used for discrimination. and Are they collinear vectors? When α ≠ 0, and They are collinear vectors; when α = 0, and They are non-collinear vectors; (6) When the catheter axis direction vector Direction vector relative to the axis of the pipe fitting When the vectors are collinear, calculate the coaxiality Δ2 between the conduit and pipe fittings: (6.1) Calculate the intersection point s(x) between the catheter axis L1 and the reference vertical plane y = 0. s ,y s ,z s ); Where f3 is a function for calculating the intersection point between the duct axis L1 and the reference vertical plane y = 0; (6.2) Calculate the intersection point l(x) between the pipeline fitting axis L2 and the reference vertical plane y = 0. l ,y l ,z l ); Where g3 is a function for calculating the intersection point between the pipeline accessory axis L2 and the reference vertical plane y = 0; (6.3) Calculate the coaxiality Δ2 between the conduit and piping fittings: (7) When the catheter axis direction vector Direction vector relative to the axis of the pipe fitting When the vectors are non-collinear, calculate the skewness Δ3 between the conduit and pipe fittings:

5. The method for detecting catheter fit, coaxiality, and deviation based on three-dimensional scanning technology according to claim 2, characterized in that, In step (4.1), the tube is deflected around the axis of the catheter, with an angle range of 0° to 180°.

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