An intelligent drilling and riveting repair method and system for delaminated damaged structures of aviation composite materials

Abstract

The present invention relates to an intelligent drilling and riveting repair method and system for a delaminated damaged structure of an aviation composite material. The intelligent repair software for the delaminated damaged structure of an aviation composite material receives and processes composite material entity data, the entity data including composite material three-dimensional point cloud data and damage detection data, constructs a visual virtual point cloud model, and calculates the minimum outer bounding ellipse of the composite material's overall damaged area based on the composite material's damage location and the overall damaged area. Subsequently, according to the damage repair process, drilling and riveting points are arranged within the minimum outer bounding ellipse of the composite material's overall damaged area, and a virtual faithful mapping scene of the actual composite material drilling and riveting repair scene is constructed and drill and rivet repair simulation verification is performed, ultimately achieving intelligent and rapid repair of composite material damage and effectively controlling the expansion of delamination. This solves the problems of traditional hole making and riveting methods being difficult and having low precision, as well as local stress concentration caused by overly dense point arrangement.

Description

Technical Field

[0001] The present invention relates to the field of intelligent drilling and riveting repair technology, and in particular to an intelligent drilling and riveting repair method and system for a delaminated damaged structure of an aviation composite material. Background Art

[0002] In recent years, composite materials have been increasingly used in aircraft manufacturing due to their advantages, including high specific stiffness, strength, lightweight properties, and significant fracture resistance. However, unlike metal components, composite components have weak interlaminar strength and are prone to delamination damage during the manufacturing process. Furthermore, factors such as incomplete curing of the material, the ingress of foreign particles, and uneven heating of the equipment can lead to problems such as interlaminar debonding, resulting in composite panels already experiencing interlaminar damage or cracks when put into service. Furthermore, existing interlaminar damage and damage can further expand under extreme operating conditions. These delamination damages can significantly reduce the overall strength and stiffness of the structure, severely impairing the flight performance of military aircraft and posing significant safety risks during service.

[0003] Composite components require complex manufacturing processes, are expensive, and have long molding cycles. Therefore, simply scrapping and replacing damaged composite panels not only increases manufacturing costs but also increases the difficulty and maintenance cycle of military aircraft. This makes it difficult to meet the demands of rapid wartime maintenance response, simple repair methods, and high reliability, severely weakening the aircraft's combat capability and battlefield survivability. To address this issue, previous researchers used perforated riveting to repair the delaminated damaged areas and their envelopes in composite panels to inhibit the expansion of delaminated damage, increase the overall strength and stiffness of the panels and assembled structure, and thus extend the service life of the structure. However, the location of initial interlaminar damage cracks and interlaminar damage induced by service loads in composite panels is highly random. The resulting interlaminar delamination areas are of uncertain location and depth, varying in size and properties, which increases the difficulty of drilling and riveting panel repairs. Currently, maintenance personnel rely primarily on experience to arrange hole drilling and riveting points, often failing to achieve optimal configurations. For delaminations of varying shapes and locations, traditional empirical methods can result in an inability to effectively control the spread of delamination, or excessively dense point arrangement, leading to localized stress concentrations. Furthermore, rapid and intelligent damage assessment, repair solutions, and repair processes for aircraft composite materials are becoming increasingly important. Summary of the Invention

[0004] In response to the deficiencies in the prior art, the present invention provides an intelligent drilling and riveting repair method and system for aviation composite layered damaged structures. The positions of initial interlayer damage cracks and interlayer damage induced by service loads in composite wall panels are highly random, and the positions and depths of the interlayer delamination areas formed therefrom are uncertain, and the sizes and properties are different, which increases the difficulty of drilling and riveting repair of wall panels. This solution receives and processes composite material entity data through intelligent repair software for aviation composite layered damaged structures, constructs a virtual model, and calculates the minimum enclosing ellipse based on the damage position and the overall damage area; then, according to the damage repair process, the drilling and rivet points are arranged within the minimum enclosing ellipse, and a virtual repair scene is constructed and the drilling and rivet repair simulation verification is verified; finally, the composite material damage is repaired, intelligent and rapid repair of the composite material damage is achieved, and the expansion of delamination is effectively controlled; thereby solving the problems of traditional hole making and riveting methods being difficult and of low precision, and local stress concentration caused by overly dense point arrangement.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: an intelligent drilling and riveting method and system for repairing delaminated damaged structures of aviation composite materials, comprising the following steps:

[0006] S1. Transmitting aviation composite material entity data to composite material intelligent repair software, where the entity data includes composite material three-dimensional point cloud data and damage detection data, and the damage detection data includes the damage location of each layer inside the composite component and the coordinates of the outermost envelope contour point of the damage area;

[0007] S2. The intelligent composite repair software constructs a visual virtual point cloud model of the material to be repaired based on the physical data. The virtual point cloud model includes a three-dimensional point cloud model for describing the structural parameters of the composite material, and a damage model for describing the damage locations of each layer within the composite material and the damage area formed by the coordinate envelope of the outermost envelope contour points.

[0008] S3. Calculate the minimum outer bounding ellipse of the overall damage area of ​​the composite material based on the damage position and the overall damage area of ​​the composite material, and draw the minimum outer bounding ellipse of the overall damage area of ​​the composite material in the composite material intelligent repair software;

[0009] S4. Arrange the drilling and riveting points within the minimum outer ellipse of the overall composite material damage area, and draw the drilling and riveting points in the composite material intelligent repair software to construct a virtual faithful mapping scene of the actual composite material drilling and riveting repair scene;

[0010] S5. The drilling and riveting points are transmitted to the virtual drilling and riveting equipment, and the drilling and riveting repair parameters are set according to the composite material drilling and riveting repair process. The virtual drilling and riveting equipment performs preliminary drilling and riveting repair simulation verification based on the drilling and riveting points and the drilling and riveting repair parameters.

[0011] S6. After successful verification, the drilling and riveting points are transmitted to the robotic repair equipment. The robotic repair equipment repairs the composite material damage according to the received drilling and riveting points and drilling and riveting repair parameters.

[0012] Furthermore, step S2 specifically includes: the intelligent repair software for composite materials loads the three-dimensional point cloud data and damage detection data of the composite materials, sends the position coordinates of each point of the data from the CPU side to the video memory buffer in a certain format, uses the point data in the video memory buffer, and combines the color, viewing angle and posture information input from the CPU side to calculate the RGB value of each pixel in the three-dimensional display window, and constructs a three-dimensional point cloud model and damage model of the composite material to be repaired.

[0013] Furthermore, the damage model has two forms of expression. One is color rendering based on the distribution of layered damage. The number of damaged layers in the depth direction of all point clouds in the composite material point cloud model is calculated in combination with the damage detection data. The maximum number of damaged layers is the number of layers of the composite material laminate itself. The point cloud data is classified according to the number of damaged layers N = (0, 1…n), where i N Indicates that there is i layer of damage. The point cloud in the composite material point cloud model is stored in containers Nvector0, Nvector1…, Nvector according to the number of damage layers N=(0,1…n). n The layer with the most damage is denoted as N max , traverse all the points in the container in turn, and render them red according to the color rendering rule green blue Perform color rendering, and finally the point with the most damage layers is rendered in red, indicating that the damage at the location of this point is the most serious. N＝0 The point is rendered in blue, indicating that there is no damage at the location of the point;

[0014] Secondly, you can choose to render colors according to the distribution of layered damage in the depth direction, so that the distribution of layered damage in depth can be observed through the color of the point cloud in the software, and the distribution of all point clouds in the entire damage area along the depth layer is marked A = (1, 2...n), where i A Indicates that in the i-th layer of the composite material along the depth direction, all point cloud data in the overall damage area are stored in containers Avector1, Avector2…, Avector according to the layer distribution A=(1,2…a) a The non-damaged point cloud data in the composite material point cloud model is stored in the container Avector, and the deepest layer is recorded as A max , traverse all the points in the container in turn, according to the color rendering rules Color rendering is performed, and the point cloud in the Avector container is rendered according to the color rule r = 1.0, g = 1.0, b = 1.0. Finally, the damage points in the deepest layer of the composite material are rendered in red, the damage points in the shallowest layer of the composite material are rendered in blue, and the non-damaged points are rendered in white.

[0015] Furthermore, in step S3, the overall damaged area is a damaged area formed by projecting the damaged areas of each layer of the composite material onto the xy plane.

[0016] Furthermore, the specific process of step S3 includes the following steps:

[0017] S31. Solve the convex hull of the overall damaged area of ​​the composite material and obtain the convex hull point set P = {p1, p2, ..., p n}, the convex hull of the contour is the smallest convex polygon containing the contour boundary, where p i represents the i-th point in the convex hull point set, p i =(x i ,y i );

[0018] S32, according to the coordinates p of the convex hull point concentration i =(x i ,y i ) Find the center p of the minimum enveloping circle of the convex hull point set radius =(x radius ,y radius ), x radius =(x1+x2+…+x n ) / n,y radius =(y1+y2+…+y n ) / n, where n is the total number of points in the point set;

[0019] S33, calculate the coordinates p of all points in the convex hull point set in sequence i =(x i ,y i ) and the center p of the minimum enveloping circle radius =(x radius ,y radius ) and take the maximum value, which is the radius r of the enveloping circle c0 ,

[0020] S34, the radius r c0 Substituting into the equation, the center of the minimum enveloping circle p radius =(x radius ,y radius ) as the initial values ​​of x0 and y0 in the optimization equation below, and successively replace the convex hull point set P = {p1, p2, ..., p nSubstitute into the optimization equation to solve the minimum outer ellipse of the point set:

[0021]

[0022]

[0023] Where A, B, and C are the parameters of the ellipse equation to be solved, x0 and y0 are the center of the ellipse to be solved, and f is a normalization coefficient that is preset to be greater than 0. Its setting value does not affect the final calculation result of the ellipse equation;

[0024] S35. Substitute the solved parameters into the ellipse center equation A(x-x0) 2 +B(x-x0)(y-y0)+c(y-y0) 2 =f, obtain the minimum outer ellipse of the entire damage area and draw it in the software.

[0025] The specific process of step S4 includes the following steps:

[0026] S401, based on the thickness, ply and material properties of the composite material structure to be repaired, and in accordance with the aviation composite material repair process, select a rivet fastener of appropriate size. The rivet fastener diameter D mao ;

[0027] S402. According to the aviation composite material repair process, for repairing multi-layer damage, the layout interval of rivets should be H Duo =20mm, and when repairing single layer damage, the layout interval of rivets should be H Dan =35mm, the effect is best, so traverse the damage point cloud data in the container Nvector2 with 2 layers of damage, calculate the difference between its inner point cloud coordinates and the ellipse center, and get the radius r of its minimum outer circle 2nv , for the difference between the point cloud coordinates and the ellipse center exceeds r 2nv It is considered to be within the range of single-layer damage;

[0028] S403, save the coordinates of the ellipse center point (x0, y0);

[0029] S404. Starting from the center point (x0, y0) of the ellipse, search for 8 surrounding points according to H=20, where the search rule is {(x+H,y),(x+H,y+H),(x+H,yH),(x,y+H),(x,yH),(xH,y),(xH,y+H),(xH,yH)}, where x and y are the point coordinates substituted into the search rule, and H is the layout interval substituted into the search rule;

[0030] S405. Exclude the retrieved coordinates of the points on the diagonal line, i.e., {(x+H, y+H), (x+H, yH), (xH, y+H), (xH, yH)}, and retain the remaining coordinates.

[0031] S406, traverse to determine whether the coordinates of the reserved point are within the ellipse, if not, execute S407, if within the ellipse, execute S408;

[0032] S407: Determine whether the current traversal has been searched. If not, continue to search the next point of the current traversal. If the traversal has been searched, determine whether there is a previous level traversal. If there is a previous level traversal, return to the previous level traversal to continue searching. If there is no previous level traversal, end the search.

[0033] S408, determine whether the retrieval point coordinates have been saved, if not, proceed to the next step; otherwise, execute S407;

[0034] S409, by Substitute into the envelope ellipse equation, where x0, y0 are the coordinates of the center of the envelope ellipse, x, y are the coordinates of the current search point, and p' is the coordinates of the circle starting from the current search point. The point whose size is far away from the center of the ellipse is determined by judging whether p′ is within the envelope ellipse to indicate whether it is necessary to drill and rivet at the search point. If it is within the envelope ellipse, the current point is saved as the position of the rivet repair and the next step is executed; if not, S407 is executed;

[0035] S410: Determine whether the distance between the search point and the center point of the ellipse is greater than r 2nv , if it is less than r 2nv , then search for 8 points around the current search point according to H = 20mm, call S405, if it is greater than r 2nv , then search for 8 points around the current search point according to H=35mm, and call S405;

[0036] S411, rivet diameter D mao Draw the drilling and rivet points for the dimensions.

[0037] Furthermore, the present invention provides a system for an intelligent drilling and riveting repair method for a delaminated damaged structure of an aviation composite material, comprising an industrial robot, an end effector, and a host computer;

[0038] The industrial robot is the moving component of the entire system of the robotic repair equipment, located outside the open space of the composite material to be processed, and is used to move the end effector to the position to be processed and inspected;

[0039] The end effector is mounted on the end flange of the industrial robot and includes a riveting module, a hole-making module, a non-destructive testing module, and a composite material point cloud scanning module; the riveting module is used to complete the riveting task by inserting nails; the hole-making module is used to perform hole-making operations; the composite material point cloud scanning module is used to obtain three-dimensional point cloud data of the composite material; the non-destructive testing module is used to perform damage detection on the composite material and obtain its damage detection data;

[0040] The host computer is used to integrate the industrial robot and the end effector into an overall system.

[0041] By means of the above technical solution, the present invention provides a method and system for intelligent drilling and riveting repair of delaminated damaged aviation composite materials, which has at least the following beneficial effects:

[0042] This solution uses intelligent repair software for delaminated damaged structures of aviation composite materials to receive and process composite material entity data, construct a virtual model, and calculate the minimum enclosing ellipse based on the damage location and the overall damage area. Subsequently, according to the damage repair process, the drilling and riveting points are arranged within the minimum enclosing ellipse, and a virtual repair scenario is constructed and the drilling and riveting repair simulation verification is carried out. Finally, the composite material damage is repaired, achieving intelligent and rapid repair of composite material damage and effectively controlling the expansion of delamination. This solves the problems of traditional hole-making and riveting methods, which are relatively difficult and have low precision, and the local stress concentration caused by the overly dense point arrangement. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0044] Figure 1 This is a flow chart of the intelligent drilling and riveting repair method for a delaminated damaged structure of an aviation composite material according to the present invention;

[0045] Figure 2 Schematic diagram of the overall damage area and enveloping ellipse in the intelligent drilling and riveting repair of delaminated damaged structures of aviation composite materials according to the present invention;

[0046] Figure 3 This is a flow chart of the layout of drilling and riveting points in the intelligent drilling and riveting repair of delaminated damaged structures of aviation composite materials used in the present invention;

[0047] Figure 4 A schematic diagram of retrieval rules for intelligent drilling and riveting repair of delaminated damaged structures of aviation composite materials according to the present invention;

[0048] Figure 5 This is a block diagram of the drilling and riveting repair system used in the method for repairing delaminated damaged structures of aviation composite materials according to the present invention;

[0049] Figure 6 This is a schematic structural diagram of the end effector used in the intelligent drilling and riveting repair of delaminated damaged structures of aviation composite materials according to the present invention. DETAILED DESCRIPTION

[0050] To make the above-mentioned objectives, features, and advantages of the present invention more clearly understood, the present invention is further described below in detail with reference to the accompanying drawings and specific embodiments. This will enable a full understanding of how this application uses technical means to solve technical problems and achieve technical effects, and to implement the invention accordingly.

[0051] Those skilled in the art will appreciate that all or part of the steps in the above-mentioned embodiment methods can be accomplished by instructing the relevant hardware through a program. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0052] Please refer to Figures 1-6 , shows a specific implementation of this embodiment. This solution receives and processes composite material entity data through intelligent repair software for aviation composite material layered damage structure, builds a virtual model, and calculates the minimum outer ellipse according to the damage location and the overall damage area; then, according to the damage repair process, the drilling and riveting points are arranged within the minimum outer ellipse, and a virtual repair scene is constructed and the drilling and riveting repair simulation verification is performed; finally, the composite material damage is repaired, and intelligent and rapid repair of composite material damage is achieved, effectively controlling the expansion of delamination; thereby solving the problem that the traditional hole making and riveting method is difficult, has low precision, and the point arrangement is too dense, causing local stress concentration. Please refer to Figure 1 This embodiment proposes an intelligent drilling and riveting method for repairing a delaminated damaged structure of an aviation composite material, the method comprising the following steps:

[0053] S1. Transmitting aviation composite material entity data to composite material intelligent repair software, where the entity data includes composite material three-dimensional point cloud data and damage detection data, and the damage detection data includes the damage location of each layer inside the composite component and the coordinates of the outermost envelope contour point of the damage area;

[0054] S2. The intelligent composite repair software constructs a visual virtual point cloud model of the material to be repaired based on the physical data. The virtual point cloud model includes a three-dimensional point cloud model for describing the structural parameters of the composite material, and a damage model for describing the damage locations of each layer within the composite material and the damage area formed by the coordinate envelope of the outermost envelope contour points.

[0055] As a preferred implementation of step S2, step S2 specifically includes: the composite material intelligent repair software loads the composite material three-dimensional point cloud data and damage detection data, sends the position coordinates of each point of the data from the CPU end to the video memory buffer in a certain format, uses the point data in the video memory buffer, combines the color, perspective and posture information input from the CPU end to calculate the RGB value of each pixel in the three-dimensional display window, and constructs a three-dimensional point cloud model and a damage model of the composite material to be repaired; wherein, the composite material intelligent repair software loads the composite material three-dimensional point cloud data to construct the composite material to be repaired three-dimensional point cloud model; the composite material intelligent repair software loads the damage detection data, and constructs the damage model based on the composite material three-dimensional point cloud model;

[0056] More specifically, the damage model has two forms of expression. One is color rendering based on the distribution of layered damage. The number of damaged layers in the depth direction of all point clouds in the composite material point cloud model is calculated in combination with damage detection data. The maximum number of damaged layers is the number of layers of the composite material laminate itself. The point cloud data is classified according to the number of damaged layers N = (0, 1...n), where i N Indicates that there is i layer of damage. The point cloud in the composite material point cloud model is stored in containers Nvector0, Nvector1…, Nvector according to the number of damage layers N=(0,1…n). n The layer with the most damage is denoted as N max , traverse all the points in the container in turn, and render them red according to the color rendering rule green blue Perform color rendering, and finally the point with the most damage layers is rendered in red, indicating that the damage at the location of this point is the most serious. N＝0 The point is rendered in blue, indicating that there is no damage at the location of the point;

[0057] Secondly, you can choose to render colors according to the distribution of layered damage in the depth direction, so that the distribution of layered damage in depth can be observed through the color of the point cloud in the software, and the distribution of all point clouds in the entire damage area along the depth layer is marked A = (1, 2...n), where i A Indicates that in the i-th layer of the composite material along the depth direction, all point cloud data in the overall damage area are stored in containers Avector1, Avector2…, Avector according to the layer distribution A=(1,2…a) a The non-damaged point cloud data in the composite material point cloud model is stored in the container Avector, and the deepest layer is recorded as A max , traverse all the points in the container in turn, according to the color rendering rules Color rendering is performed, and the point cloud in the Avector container is rendered according to the color rule r = 1.0, g = 1.0, b = 1.0. Finally, the damage points in the deepest layer of the composite material are rendered in red, the damage points in the shallowest layer of the composite material are rendered in blue, and the non-damaged points are rendered in white.

[0058] S3, calculate the minimum outer bounding ellipse 2 of the composite material's overall damage area according to the composite material's damage position and the overall damage area 1, and draw the minimum outer bounding ellipse of the composite material's overall damage area in the composite material intelligent repair software, such as Figure 2 As shown;

[0059] More specifically, the overall damaged area is the damaged area formed by projecting the damaged areas of each layer of the composite material onto the xy plane;

[0060] As a preferred implementation of step S3, the specific process of step S3 includes the following steps:

[0061] S31. Solve the convex hull of the overall damaged area of ​​the composite material and obtain the convex hull point set P = {p1, p2, ..., p n}, the convex hull of the contour is the smallest convex polygon containing the contour boundary, where p i Represents the i-th point in the convex hull point set, p i =(x i ,y i );

[0062] S32, according to the coordinates p of the convex hull point concentration i =(x i ,y i ) Find the center p of the minimum enveloping circle of the convex hull point set radius =(x radius ,y radius ), x radius =(x1+x2+…+x n ) / n,y radius =(y1+y2+…+y n ) / n, where n is the total number of points in the point set;

[0063] S33, calculate the coordinates p of all points in the convex hull point set in sequence i =(x i ,y i ) and the center p of the minimum enveloping circle radius =(x radius ,y radius ) and take the maximum value, which is the radius r of the enveloping circle c0 ,

[0064] S34, the radius rc0 Substituting into the equation, the center of the minimum enveloping circle p radius =(x radius ,y radius ) as the initial values ​​of x0 and y0 in the optimization equation below, and successively replace the convex hull point set P = {p1, p2, ..., p n Substitute into the optimization equation to solve the minimum outer ellipse of the point set:

[0065]

[0066]

[0067] Where A, B, and C are the parameters of the ellipse equation to be solved, x0 and y0 are the center of the ellipse to be solved, and f is a normalization coefficient that is preset to be greater than 0. Its setting value does not affect the final calculation result of the ellipse equation;

[0068] More specifically, the optimization equation for solving the minimum enclosing ellipse in step S34 is obtained by the following steps:

[0069] S341, the elliptic equation Ax in the form of a quadratic curve 2 +Bxy+Cy 2 +Dx+Ey+F=0 is transformed into the central form equation A(x-x0) 2 +B(x-x0)(y-y0)+c(y-y0) 2 =f, we get:

[0070]

[0071] Where A, B, C are the parameters of the ellipse equation, x0, y0 are the centers of the ellipse, and f is a normalization coefficient that is preset to be greater than 0;

[0072] S342. Write the central form equation as a quadratic form, that is For real symmetric matrices There exists an orthogonal matrix Q such that If det(Q) = 1 and the area of ​​the ellipse Area(ε) = πab is used as the criterion for calculating the minimum ellipse, we get:

[0073] a 2 =1 / λ1,b 2 =1 / λ2,λ1>0,λ2>0;

[0074] So there is That is, when λ1λ2 takes the maximum value, the area of ​​the ellipse is the smallest, where det(Q) is the determinant of Q, a and b are the semi-major axis length and semi-minor axis length of the ellipse respectively;

[0075] S343, take f in the central form equation as the normalized quantity, according to And λ1>0,λ2>0, we get:

[0076] 4AC-B 2 >0, (A+C)f>0;

[0077] S344, considering the convex hull point set P of the overall damaged area contour of the composite material = {p1, p2, ..., p n} in the ellipse ε, where p i represents the i-th point in the damage area contour point set, p i =(x i ,y i ), then:

[0078] A(x i -x0) 2 +B(x i -x0)(y i -y0)+c(y i -y0) 2 ≤f;

[0079] S345、 Considering that the area of ​​the minimum enclosing ellipse of a point set does not exceed the area of ​​its minimum enclosing circle, Right now

[0080] S35. Substitute the solved parameters into the ellipse center equation A(x-x0) 2 +B(x-x0)(y-y0)+c(y-y0) 2 =f, obtain the minimum outer ellipse of the entire damage area and draw it in the software.

[0081] S4. Layout the drilling and riveting points within the minimum outer ellipse of the overall damage area of ​​the composite material, and draw the drilling and riveting points in the composite material intelligent repair software, such as Figure 3 As shown, a virtual faithful mapping scene of the actual composite material drilling and riveting repair scene is constructed;

[0082] As a preferred implementation of step S4, the specific process of step S4 includes the following steps:

[0083] S401, based on the thickness, ply and material properties of the composite material structure to be repaired, and in accordance with the aviation composite material repair process, select a rivet fastener of appropriate size. The rivet fastener diameter D mao ;

[0084] S402. According to the aviation composite material repair process, for repairing multi-layer damage, the layout interval of rivets should be H Duo =20mm, and when repairing single layer damage, the layout interval of rivets should be H Dan=35mm, the effect is best, so traverse the damage point cloud data in the container Nvector2 with 2 layers of damage, calculate the difference between its inner point cloud coordinates and the ellipse center, and get the radius r of its minimum outer circle 2nv , for the difference between the point cloud coordinates and the ellipse center exceeds r 2nv It is considered to be within the range of single-layer damage;

[0085] S403, save the coordinates of the ellipse center point (x0, y0);

[0086] S404, starting from the center point of the ellipse (x0, y0), such as Figure 4 As shown, according to H=20, 8 points around it are retrieved, where the retrieval rule is {(x+H,y),(x+H,y+H),(x+H,yH),(x,y+H),(x,yH),(xH,y),(xH,y+H),(xH,yH)}, x and y are the point coordinates substituted into the retrieval rule, and H is the layout interval substituted into the retrieval rule;

[0087] S405. Exclude the retrieved coordinates of the points on the diagonal line, i.e., {(x+H, y+H), (x+H, yH), (xH, y+H), (xH, yH)}, and retain the remaining coordinates.

[0088] S406, traverse to determine whether the coordinates of the reserved point are within the ellipse, if not, execute S407, if within the ellipse, execute S408;

[0089] S407: Determine whether the current traversal has been searched. If not, continue to search the next point of the current traversal. If the traversal has been searched, determine whether there is a previous level traversal. If there is a previous level traversal, return to the previous level traversal to continue searching. If there is no previous level traversal, end the search.

[0090] S408, determine whether the retrieval point coordinates have been saved, if not, proceed to the next step; otherwise, execute S407;

[0091] S409, by Substitute into the envelope ellipse equation, where x0, y0 are the coordinates of the center of the envelope ellipse, x, y are the coordinates of the current search point, and p' is the coordinates of the circle starting from the current search point. The point whose size is far away from the center of the ellipse is determined by judging whether p′ is within the envelope ellipse to indicate whether it is necessary to drill and rivet at the search point. If it is within the envelope ellipse, the current point is saved as the position of the rivet repair and the next step is executed; if not, S407 is executed;

[0092] S410: Determine whether the distance between the search point and the center point of the ellipse is greater than r 2nv , if it is less than r 2nv, then search for 8 points around the current search point according to H = 20mm, call S405, if it is greater than r 2nv , then search for 8 points around the current search point according to H=35mm, and call S405;

[0093] S411, rivet diameter D mao Draw the drilling and rivet points for the dimensions.

[0094] S5. The drilling and riveting points are transmitted to the virtual drilling and riveting equipment, and the drilling and riveting repair parameters are set according to the composite material drilling and riveting repair process. The virtual drilling and riveting equipment performs preliminary drilling and riveting repair simulation verification based on the drilling and riveting points and the drilling and riveting repair parameters.

[0095] S6. After successful verification, the drilling and riveting points are transmitted to the robotic repair equipment. The robotic repair equipment repairs the composite material damage according to the received drilling and riveting points and drilling and riveting repair parameters.

[0096] The present invention also provides a system for intelligent drilling and riveting repair of delaminated damaged structures of aviation composite materials, including an industrial robot, an end effector and a host computer, such as Figure 5 As shown;

[0097] The industrial robot is the moving component of the entire system of the robotic repair equipment, located outside the open space of the composite material to be processed, and is used to move the end effector to the position to be processed and inspected;

[0098] The end effector is installed on the end flange of the industrial robot and is used for composite material point cloud scanning, damage detection and drilling and riveting repair; the end effector includes a riveting module 3, a hole making module 4, a non-destructive testing module 5, and a composite material point cloud scanning module 6; Figure 6 As shown, the riveting module 3 is used to complete the riveting task by inserting nails; the hole making module 4 is used to perform the hole making operation; the composite material point cloud scanning module 6 is used to obtain the three-dimensional point cloud data of the composite material; the non-destructive testing module 5 is used to perform damage detection on the composite material and obtain its damage detection data;

[0099] The host computer is used to integrate the industrial robot and the end effector into an overall system.

[0100] In summary, the beneficial effects of the present invention are as follows:

[0101] The present invention receives and processes composite material entity data through intelligent repair software for aviation composite material delaminated damaged structures, constructs a virtual model, and calculates the minimum enclosing ellipse based on the damage location and the overall damage area. Subsequently, according to the damage repair process, the drilling and riveting points are arranged within the minimum enclosing ellipse, and a virtual repair scenario is constructed and drilling and riveting repair simulation verification is performed. Finally, the composite material damage is repaired, and intelligent and rapid repair of composite material damage is achieved, effectively controlling the expansion of delamination. This solves the problems of traditional hole making and riveting methods, which are relatively difficult and have low precision, and local stress concentration caused by overly dense point arrangement.

[0102] In the description of this specification, the reference terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless they are mutually inconsistent.

[0103] The logic and / or steps represented in the flowchart or otherwise described herein may be considered, for example, as an ordered list of executable instructions for implementing logical functions, and may be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device).

[0104] The above embodiments provide a detailed introduction to the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. An intelligent drilling and riveting method for repairing delaminated damaged structures of aviation composite materials, characterized in that: The following steps are involved: S1. Transmitting aviation composite material entity data to composite material intelligent repair software, where the entity data includes composite material three-dimensional point cloud data and damage detection data, and the damage detection data includes the damage location of each layer inside the composite component and the coordinates of the outermost envelope contour point of the damage area; S2. The intelligent composite repair software constructs a visual virtual point cloud model of the material to be repaired based on the physical data. The virtual point cloud model includes a three-dimensional point cloud model for describing the structural parameters of the composite material, and a damage model for describing the damage locations of each layer within the composite material and the damage area formed by the coordinate envelope of the outermost envelope contour points. S3. Calculate the minimum outer bounding ellipse of the overall damage area of ​​the composite material based on the damage position and the overall damage area of ​​the composite material, and draw the minimum outer bounding ellipse of the overall damage area of ​​the composite material in the composite material intelligent repair software; S4. Arrange the drilling and riveting points within the minimum outer ellipse of the overall composite material damage area, and draw the drilling and riveting points in the composite material intelligent repair software to construct a virtual faithful mapping scene of the actual composite material drilling and riveting repair scene; S401, based on the thickness, ply and material properties of the composite material structure to be repaired, and in accordance with the aviation composite material repair process, select a rivet fastener of appropriate size. The rivet fastener diameter D mao ; S402. According to the aviation composite material repair process, for repairing multi-layer damage, the layout interval of rivets should be H Duo =20mm, and when repairing single layer damage, the layout interval of rivets should be H Dan =35mm, the effect is best, so traverse the damage point cloud data in the container Nvector2 with 2 layers of damage, calculate the difference between its inner point cloud coordinates and the ellipse center, and get the radius r of its minimum outer circle 2nv , for the difference between the point cloud coordinates and the ellipse center exceeds r 2nv It is considered to be within the range of single-layer damage; S403, save the coordinates of the ellipse center point (x0, y0); S404. Starting from the center point (x0, y0) of the ellipse, search for 8 surrounding points according to H=20, where the search rule is {(x+H,y),(x+H,y+H),(x+H,yH),(x,y+H),(x,yH),(xH,y),(xH,y+H),(xH,yH)}, where x and y are the point coordinates substituted into the search rule, and H is the layout interval substituted into the search rule; S405. Exclude the retrieved coordinates of the points on the diagonal line, i.e., {(x+H, y+H), (x+H, yH), (xH, y+H), (xH, yH)}, and retain the remaining coordinates. S406, traverse to determine whether the coordinates of the reserved point are within the ellipse, if not, execute S407, if within the ellipse, execute S408; S407: Determine whether the current traversal has been searched. If not, continue to search the next point of the current traversal. If the traversal has been searched, determine whether there is a previous level traversal. If there is a previous level traversal, return to the previous level traversal to continue searching. If there is no previous level traversal, end the search. S408, determine whether the retrieval point coordinates have been saved, if not, proceed to the next step; Otherwise, execute S407; S409, by Substitute into the envelope ellipse equation, where x0, y0 are the coordinates of the center of the envelope ellipse, x, y are the coordinates of the current search point, and p ' To start from the current access point The size of the point far away from the center of the ellipse is determined by judging p ' Whether it is within the envelope ellipse indicates whether it is necessary to drill and rivet at the search point. If it is within the envelope ellipse, the current point is saved as the location for rivet repair and the next step is executed; If not, execute S407; S410: Determine whether the distance between the search point and the center point of the ellipse is greater than r 2nv , if it is less than r 2nv , then search for 8 points around the current search point according to H = 20mm, call S405, if it is greater than r 2nv , then search for 8 points around the current search point according to H=35mm, and call S405; S411, rivet diameter D mao Draw the drilling and riveting points for the dimensions; S5. The drilling and riveting points are transmitted to the virtual drilling and riveting equipment, and the drilling and riveting repair parameters are set according to the composite material drilling and riveting repair process. The virtual drilling and riveting equipment performs preliminary drilling and riveting repair simulation verification based on the drilling and riveting points and the drilling and riveting repair parameters. S6. After successful verification, the drilling and riveting points are transmitted to the robotic repair equipment. The robotic repair equipment repairs the composite material damage according to the received drilling and riveting points and drilling and riveting repair parameters.

2. The intelligent drilling and riveting method for repairing delaminated damaged aviation composite materials according to claim 1, characterized in that: Step S2 specifically includes: the intelligent repair software for composite materials loads the three-dimensional point cloud data and damage detection data of the composite materials, sends the position coordinates of each point of the data from the CPU to the video memory buffer in a certain format, uses the point data in the video memory buffer, and combines the color, viewing angle and posture information input from the CPU to calculate the RGB value of each pixel in the three-dimensional display window, and constructs a three-dimensional point cloud model and damage model of the composite material to be repaired.

3. The intelligent drilling and riveting method for repairing delaminated damaged aviation composite materials according to claim 2, characterized in that: The damage model has two forms of expression. One is color rendering based on the distribution of layered damage on the number of damaged layers. The number of damaged layers in the depth direction of all point clouds in the composite point cloud model is calculated in combination with damage detection data. The maximum number of damaged layers is the number of layers of the composite laminate itself. The point cloud data is classified according to the number of damaged layers N = (0, 1...n), where i N Indicates that there is i layer of damage. The point cloud in the composite material point cloud model is stored in containers Nvector0, Nvector1…, Nvector according to the number of damage layers N=(0,1…n). n The layer with the most damage is denoted as N max , traverse all the points in the container in turn, and render them red according to the color rendering rule green blue Perform color rendering, and finally the point with the most damage layers is rendered in red, indicating that the damage at the location of this point is the most serious. N＝0 The point is rendered in blue, indicating that there is no damage at the location of the point; Secondly, color rendering is performed according to the distribution of layered damage in the depth direction, so that the distribution of layered damage in depth can be observed through the color of the point cloud in the software, and the distribution of all point clouds along the depth layers in the overall damage area is marked A = (1, 2…n), where i A Indicates that in the i-th layer of the composite material along the depth direction, all point cloud data in the overall damage area are stored in containers Avector1, Avector2…, Avector according to the layer distribution A=(1,2…a) a The non-damaged point cloud data in the composite material point cloud model is stored in the container Avector, and the deepest layer is recorded as A max , traverse all the points in the container in turn, according to the color rendering rules Color rendering is performed, and the point cloud in the Avector container is rendered according to the color rule r = 1.0, g = 1.0, b = 1.

0. Finally, the damage points in the deepest layer of the composite material are rendered in red, the damage points in the shallowest layer of the composite material are rendered in blue, and the non-damaged points are rendered in white.

4. The intelligent drilling and riveting method for repairing delaminated damaged aviation composite materials according to claim 1, characterized in that: In step S3, the overall damaged area is a damaged area formed by projecting the damaged areas of each layer of the composite material onto the xy plane.

5. The intelligent drilling and riveting method for repairing delaminated damaged aviation composite materials according to claim 4, characterized in that: The specific process of step S3 includes the following steps: S31. Solve the convex hull of the overall damaged area of ​​the composite material and obtain the convex hull point set P = {p1, p2, ..., p n }, the convex hull of the contour is the smallest convex polygon containing the contour boundary, where p i Represents the i-th point in the convex hull point set, p i =(x i ,y i ); S32, according to the coordinates p of the convex hull point concentration i =(x i ,y i ) Find the center p of the minimum enveloping circle of the convex hull point set radius =(x radius ,y radius ), x radius =(x1+x2+…+x n ) / n,y radius =(y1+y2+…+y n ) / n, where n is the total number of points in the point set; S33, calculate the coordinates p of all points in the convex hull point set in sequence i =(x i ,y i ) and the center p of the minimum enveloping circle radius =(x radius ,y radius ) and take the maximum value, which is the radius r of the enveloping circle c0 , S34, the radius r c0 Substituting into the equation, the center of the minimum enveloping circle p radius =(x radius ,y radius ) as the initial values ​​of x0 and y0 in the optimization equation below, and successively replace the convex hull point set P = {p1, p2, ..., p n Substitute into the optimization equation to solve the minimum outer ellipse of the point set: Where A, B, and C are the parameters of the ellipse equation to be solved, x0 and y0 are the center of the ellipse to be solved, and f is a normalization coefficient that is preset to be greater than 0. Its setting value does not affect the final calculation result of the ellipse equation; S35. Substitute the solved parameters into the ellipse center equation A(x-x0) 2 +B(x-x0)(y-y0)+c(y-y0) 2 =f, obtain the minimum outer ellipse of the entire damage area and draw it in the software.

6. The system for the intelligent drilling and riveting method for repairing delaminated damaged aviation composite materials according to any one of claims 1 to 5, characterized in that: Including industrial robots, end effectors and host computers; The industrial robot is the moving component of the entire system of the robotic repair equipment, located outside the open space of the composite material to be processed, and is used to move the end effector to the position to be processed and inspected; The end effector is mounted on the end flange of the industrial robot and includes a riveting module, a hole-making module, a non-destructive testing module, and a composite material point cloud scanning module; the riveting module is used to complete the riveting task by inserting nails; the hole-making module is used to perform hole-making operations; the composite material point cloud scanning module is used to obtain three-dimensional point cloud data of the composite material; the non-destructive testing module is used to perform damage detection on the composite material and obtain its damage detection data; The host computer is used to integrate the industrial robot and the end effector into an overall system.

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