Airplane flexible tool system and control method thereof

Abstract

The invention discloses an aircraft flexible tool system and a control method thereof. The aircraft flexible tool system comprises a framework clamping tool and a plurality of skin clamping tools. The framework clamping tool comprises a rack frame and a plurality of telescopic support legs, a plurality of movable clamping jaw set sliding blocks are arranged on the rack frame, and a plurality of movable clamping jaw assemblies are arranged on each clamping jaw set sliding block. The skin clamping tool comprises a machine base, a plurality of suction cup set sliding blocks are arranged on the machine base, a vertical guide hole is formed in each suction cup set sliding block, and a plurality of movable suction cup assemblies are arranged in the vertical guide holes. The horizontal skin tool can adapt to assembly of skins with different curvatures, small-size or small-curvature elements can be directly achieved through the horizontal skin tool, for large-curvature elements, clamp bodies on the two sides are adjusted to rise, then a vacuum suction cup moves, an adsorption dot matrix can be formed, clamping is achieved, and the suction cup head can also conduct self-adaptive rotation according to the skins with the different curvatures.

Description

Technical Field

[0001] The invention relates to the field of aircraft manufacturing, and in particular to an aircraft flexible tooling system and an installation method thereof. Background Art

[0002] At present, the aviation equipment manufacturing industry, as one of the ten key development areas of the country, is of great significance to economic development, national security, scientific and technological innovation, transportation, etc. It is an important manifestation of a country's comprehensive strength and competitiveness.

[0003] Aircraft assembly is a critical link in the entire aviation manufacturing process, and the workload accounts for about half of the entire aircraft manufacturing. However, the characteristics of aircraft assembly are that the operation workload is large, the connection technology involved is relatively wide, the methods and processes to ensure the interchangeability and coordination of component assembly are relatively complex, and the strength of the docking surface and the accuracy of the aerodynamic shape must be ensured during the entire assembly process. At present, traditional mechanical tooling has the following problems:

[0004] 1. Traditional mechanical tooling cannot adjust the clamping force and supporting force of the workpiece according to different materials;

[0005] 2. The traditional mechanical tooling has poor flexibility and cannot adapt to the assembly of skins with different curvatures;

[0006] 3. Traditional mechanical tooling cannot adaptively change the support position of the workpiece, and the support and fixation effect on the workpiece is poor.

[0007] Therefore, in response to the above problems, it is necessary to propose an aircraft flexible tooling system and a control method thereof which is suitable for workpieces of different materials, has better flexibility and better support and fixing effects. Summary of the invention

[0008] In view of the above-mentioned deficiencies in the prior art, the present invention provides an aircraft flexible tooling system and a control method thereof.

[0009] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0010] Provided are an aircraft flexible tooling system and a control method thereof, comprising a movable skeleton clamping tooling and a plurality of skin clamping toolings; the skeleton clamping tooling comprises a frame and a plurality of telescopic bracket legs fixed to the bottom of the frame, the frame is provided with a plurality of movable groups of claw group sliding blocks, each group of claw group sliding blocks is provided with a plurality of movable claw assemblies; the skin clamping tooling comprises a base, the base is provided with a plurality of suction cup group sliding blocks, each group of suction cup group sliding blocks is provided with a vertical guide hole, and a plurality of movable suction cup assemblies are provided in the vertical guide hole.

[0011] Furthermore, the skin clamping jig comprises a left skin clamping jig, a middle skin clamping jig and a right skin clamping jig of the same structure. The left skin clamping jig and the middle skin clamping jig, as well as the middle skin clamping jig and the right skin clamping jig are hinged through a hinge axis. Telescopic devices are provided at the bottom of the left skin clamping jig and the right skin clamping jig, and the telescopic devices are used to adjust the angles among the left skin clamping jig, the right skin clamping jig and the middle skin clamping jig.

[0012] Furthermore, the suction cup assembly includes a universal suction cup, a suction cup telescopic cylinder and a suction cup base. The bottom of the suction cup telescopic cylinder is installed in the suction cup base through a telescopic mechanism, and the top of the suction cup telescopic cylinder is provided with a suction cup adsorption air inlet for installing the universal suction cup; a guide limit ring is provided on the outside of the suction cup base, and a suction cup limit guide groove cooperating with the guide limit ring is provided on the sliding block of the suction cup group.

[0013] Furthermore, it also includes a first driving mechanism, which is used to drive the sliding block of the claw group to move. The first driving mechanism includes a first rack, a first gear and a first motor. The first rack is arranged on the top of the frame, the first gear is arranged at the end of the sliding block of the claw group, the first rack is meshed with the first gear, and the first gear is fixed to the output end of the first motor.

[0014] Furthermore, it also includes a second driving mechanism, which is used to drive the claw assembly to move, and the second driving mechanism includes a second rack, a second gear and a second motor, the second rack is fixed to the side of the claw group sliding block, the claw group sliding block is provided with a sliding bar hole for installing the claw assembly, the top of the claw assembly is fixed with a claw sliding block through the sliding bar hole, the second gear is installed on the output shaft of the second motor, the second rack is meshed with the second gear, and the second motor is fixedly connected to the claw sliding block;

[0015] Furthermore, it also includes a third driving mechanism, which is used to drive the suction cup group sliding block to move. The third driving mechanism includes a third rack, a third gear and a third motor. The third rack is fixed to the side of the machine base, and the third gear is installed at the output end of the third motor. The third rack and the third gear are meshingly connected, and the third motor is fixed to the end of the suction cup group sliding block.

[0016] Furthermore, it also includes a fourth driving mechanism, which is used to drive the suction cup assembly to move. The fourth driving mechanism includes a fourth rack, a fourth gear and a fourth motor. The fourth rack is fixed to the side of the suction cup assembly sliding block, the fourth gear is meshed with the fourth gear, and the fourth gear is fixedly connected to the suction cup assembly through a connecting shaft. The suction cup assembly is provided with a traction shaft hole that cooperates with the connecting shaft, and the suction cup assembly sliding block is provided with a horizontal guide hole that cooperates with the traction shaft hole.

[0017] An aircraft flexible tooling system and a control method thereof, comprising the following steps:

[0018] S1: First, the three-dimensional model parameters of the wall panel are imported into the industrial software, and then the wall panel and the flexible tooling model are simulated and assembled to obtain the skin pre-assembly digital model;

[0019] S2: Determine the working position coordinates of all the clamps and all the suction cup assemblies through the arrangement of the clamps and suction cup assemblies and the optimization model between the minimum deformation of the skin and the skeleton;

[0020] S3: According to the working position coordinates of the claw assembly and the suction cup assembly, first control the claw assembly sliding block and the suction cup assembly sliding block to move to the corresponding working position, and then control the claw assembly and the suction cup assembly to move to the corresponding working position;

[0021] S4: After the claw assembly and the suction cup assembly move to the working position, the claw assembly is first controlled to clamp the frame to clamp the skin to the position above the suction cup assembly, and then the claw assembly is controlled to release the frame, and at the same time the suction cup telescopic tube is controlled to extend, and the universal suction cup is adaptively rotated to the tangent adsorption position according to the curvature of the clamped aircraft skin and the adaptive rotation algorithm;

[0022] S5: After the universal suction cup rotates to the tangential adsorption position, the suction cup assembly is controlled to start adsorption and the assembly operation is performed.

[0023] In step S2, the optimization model is:

[0024] Minimum deformation of skin and skeleton MIN{S max (X), T max (Y)}Satisfies:

[0025]

[0026] X=(x 1 , x 2 , ..., x q );

[0027] Y=(y 1 ,y 2 , …, y p );

[0028] (x u ,y l )∈A; u=1,2,…,q; l=1,2,…,p;

[0029] Where: X is the suction cup positioning method; Y is the clamping method of the claw; m is the number of aircraft shells with different curvatures; S max (X) is the maximum deformation of the skin; T max (Y) is the maximum deformation of the skeleton; S i (X) is the maximum deformation of the skin of the ith aircraft shell; T l(Y) is the maximum deformation of the skeleton of the i-th aircraft shell; A is the feasible design domain of the arrangement of the claws and vacuum suction cups under certain constraints. u is the u-th suction cup positioning method; y l is the lth claw positioning method; q is the number of suction cup arrangement methods; p is the number of claw arrangement methods.

[0030] In step S4, the steps of the adaptive rotation algorithm are as follows:

[0031] S41: interpolating a data point set of the aircraft shell model to be assembled into a smooth two-dimensional curve function;

[0032] Specifically, the aircraft shell to be assembled is divided into several planes through the surface where the suction cup assembly track is located, and the shell model point set of each plane is interpolated into a two-dimensional curve function. The obtained two-dimensional curve function is as follows:

[0033]

[0034] Among them, h i =x i -x i-1 ,h i is the distance between the i-1th shell model point and the i-th shell model point; M i-1 is the slope of the i-1th shell model point; M i is the slope of the i-th shell model point; y i-1 is the ordinate of the i-1th shell model point; y i is the ordinate of the i-th shell model point; f i (x) is the function after interpolation; x is the coordinate of the coordinate point on the X-axis; y is the coordinate of the coordinate point on the Y-axis; x i-1 is the coordinate of the i-1th shell model point on the X-axis, x i is the coordinate of the i-th shell model point on the X-axis.

[0035] S42: Calculate the adaptive rotation angle of the suction cup head on the corresponding track according to the interpolated two-dimensional curve function. The formula for calculating the adaptive rotation angle of the suction cup head is as follows:

[0036]

[0037] Where: α is the adaptive rotation angle of the suction cup head; l 0 is the coordinate of the center of the curvature circle in the x direction; h 0 is the coordinate of the center of the curvature circle in the y direction; κ is the curvature of the specified coordinate; l 1is the coordinate of the suction cup in the x direction; R is the radius of curvature of the specified coordinate; L is the length of the suction cup head; x is the coordinate of the coordinate point on the X axis; y is the coordinate of the coordinate point on the Y axis; y′ is the derivative of the function value of the coordinate point with respect to the independent variable of the X axis, and y″ is the second-order derivative of the function value of the coordinate point with respect to the independent variable of the X axis.

[0038] The beneficial effects of the present invention are:

[0039] The three-position skin clamping tooling in the present invention has a high degree of flexibility and can adapt to the assembly of skins with different curvatures; for the assembly of wall panel components, small-sized or small-curvature components can be directly realized by the horizontal skin tooling without adjusting the posture of the skin clamping tooling on both sides; for large-curvature components, the skin clamping tooling on both sides is adjusted to rise, and then the movement of the vacuum suction cup can form an adsorption point array for clamping, and the suction cup head can also rotate adaptively according to the skins with different curvatures.

[0040] The clamping claw assembly of the present invention has high clamping stability. The suction cup assembly is a universal suction head, which can fit the skin component tightly and detect air leakage in real time. The overall adjustable stability of the tooling is high. For skeleton tooling with relatively large mass, the use of mechanical clamps can provide greater clamping force to ensure stable clamping.

[0041] The present invention can reduce the deformation of the workpiece. The skin structure is generally a thin-walled component. The tooling uses a vacuum suction cup as a clamping element, wherein the clamping force can be adjusted according to different materials. At the same time, it can reduce the change of the support position according to the maximum deformation of the workpiece, thereby preventing the deformation of the workpiece to the greatest extent.

[0042] The present invention has strong operability, a small footprint, a high space utilization rate, and some internal space is reserved, which is convenient for workers to operate and reduces their labor intensity. The tooling system of the present invention cooperates with the control method to increase the intelligence of assembly and reduce manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the overall structure of the flexible tooling system;

[0044] Figure 2 It is a schematic diagram of the skeleton clamping tooling structure;

[0045] Figure 3 for Figure 2 A partial enlarged view of the middle A;

[0046] Figure 4 Schematic diagram of the skin clamping tooling structure Figure 1 ;

[0047] Figure 5 Schematic diagram of the skin clamping tooling structure Figure 2 ;

[0048] Figure 6 It is a partial structural schematic diagram of the left skin clamping tooling;

[0049] Figure 7 It is a structural schematic diagram of the sliding block of the suction cup group;

[0050] Figure 8 It is a front view of the sliding block of the suction cup assembly;

[0051] Fig. 9 for Figure 8 Cross-sectional view in the BB direction;

[0052] Fig.10 It is a partial structural schematic diagram of the vacuum suction cup assembly;

[0053] Fig.11 This is an exploded view of the vacuum suction cup;

[0054] Fig.12 This is an exploded view of the hydraulic telescopic column;

[0055] Fig.13 It is a schematic diagram of the intelligent control system;

[0056] The main components in the figure are described as follows:

[0057] 1. Skeleton clamping tool; 11. Rack frame; 12. Telescopic bracket leg; 13. Claw assembly sliding block; 14. First rack; 15. First gear; 16. Upper sliding bar hole; 17. Claw sliding block; 19. Claw assembly; 110. Second rack; 111. Second gear;

[0058] 2. Left skin clamping tooling; 21. Suction cup assembly sliding block; 211. Vertical guide hole; 212. Horizontal guide hole; 213. Suction cup limit guide groove;

[0059] 22. The third rack; 23. The third gear; 24. The fourth rack; 25. The fourth gear; 26. The suction cup assembly limit plate; 27. The base; 28. The suction cup assembly; 281. The universal suction cup; 282. The suction cup adsorption air inlet; 283. The suction cup telescopic cylinder; 284. The suction cup base; 285. The guide limit ring; 286. The traction shaft hole;

[0060] 3. Middle skin clamping tool; 4. Right skin clamping tool; 5. Hydraulic telescopic column; 51. Articulated seat; 52. Upper telescopic rod; 53. Middle telescopic rod; 54. Bottom telescopic rod; 6. Articulated shaft. DETAILED DESCRIPTION

[0061] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0062] like Figure 1 As shown, the aircraft flexible fixture system and the control method thereof include a movable skeleton clamping fixture 1 and three skin clamping fixtures.

[0063] like Figure 2 and 3 As shown, the skeleton clamping fixture 1 includes a frame 11 and a plurality of telescopic bracket legs 12 fixed to the bottom of the frame 11. The frame 11 is provided with a plurality of movable groups of claw group sliding blocks 13. Each group of claw group sliding blocks 13 is provided with a plurality of movable claw assemblies 19. Each group of claw group sliding blocks 13 is preferably provided with two claw assemblies 19. The claw assemblies 19 are preferably activated pneumatic claws. The skin clamping fixture 3 includes a left skin clamping fixture 2, a middle skin clamping fixture 3 and a right skin clamping fixture 4 with the same structure. The left skin clamping fixture 2 and the middle skin clamping fixture 3, and the middle skin clamping fixture 3 and the right skin clamping fixture 4 are hinged by a hinge shaft 6. The left skin clamping fixture 2, the middle skin clamping fixture 3 and the right skin clamping fixture 4 are provided with hinge ends that cooperate with the hinge shaft 6. The bottom of the left skin clamping fixture 2 and the right skin clamping fixture 4 are both provided with telescopic devices, which are used to adjust the angle between the left skin clamping fixture 2, the right skin clamping fixture 4 and the middle skin clamping fixture 3. If the curvature of the assembled skin is small and the overall surface is relatively flat, it is only necessary to control the vacuum suction cup to move in the Z direction; if the curvature of the assembled skin is large and the overall surface is relatively curved, the telescopic devices on both sides are controlled to provide power to the left skin clamping fixture 2 and the right skin clamping fixture 4 on both sides, so that the left skin clamping fixture 2 and the right skin clamping fixture 4 rotate around the middle skin clamping fixture 3, and the working curvature of the fixture system is adaptively changed. A suction cup group limit plate 26 is provided between adjacent suction cup group sliding blocks 21 on the same skin clamping fixture, and the suction cup group limit plate 26 is fixed on the machine base 27. The suction cup group limit plate 26 is used to limit the position of the suction cup group sliding block 21.

[0064] The bottom of the telescopic support leg 12 can be provided with a roller matching track to facilitate the horizontal movement of the skeleton clamping tool 1. The support leg can be lifted and lowered by two telescopic support legs 12 in linkage, or by a single support leg. When the support leg is lifted and lowered individually, specifically, the telescopic support leg 12 includes an upper telescopic cylinder and a lower fixed cylinder, the upper telescopic cylinder is nested in the lower fixed cylinder, a screw is rotatably installed at the bottom of the lower fixed cylinder, a nut matching the screw is fixed at the bottom of the upper telescopic cylinder, a first bevel gear is installed at the bottom of the screw, the first bevel gear is connected to the second bevel gear, the first bevel gear is meshed with the second bevel gear, the second bevel gear is installed on the output shaft of the motor, and the telescopic control of the upper telescopic cylinder is realized by the motor, so as to realize the telescopic operation of the telescopic support leg 12.

[0065] The first driving mechanism is also included, and the first driving mechanism is used to drive the sliding block 13 of the clamping claw group to move. The first driving mechanism includes a first rack 14, a first gear 15 and a first motor. The first rack 14 is arranged on the top of the frame frame 11, and the first gear 15 is arranged at the end of the sliding block 13 of the clamping claw group. The first rack 14 is meshed with the first gear 15, and the first gear 15 is fixed to the output end of the first motor. By controlling the first motor, each group of driving the sliding block 13 of the clamping claw group can be moved to the desired working position.

[0066] It also includes a second driving mechanism, which is used to drive the claw assembly 19 to move. The second driving mechanism includes a second rack 110, a second gear 111 and a second motor. The second rack 110 is fixed to the side of the claw group sliding block 13. The claw group sliding block 13 is provided with a sliding bar hole 16 for installing the claw assembly 19. The top of the claw assembly 19 is fixed with a claw sliding block 17 through the sliding bar hole 16. The second gear 111 is installed on the output shaft of the second motor. The second rack 110 is meshed with the second gear 111, and the second motor is fixedly connected to the claw sliding block 17. By controlling the second motor, each claw assembly 19 can be moved to the desired working position.

[0067] like Figure 4 , 5 , 6, 7, 8, 9 and 10, the skin clamping tooling includes a machine base 27, on which are disposed a plurality of suction cup group sliding blocks 21, each of which is provided with a vertical guide hole 211, in which are disposed a plurality of movable suction cup assemblies 28, and the suction cup assemblies 28 are preferably vacuum suction cups.

[0068] like Figure 7As shown, the third driving mechanism is also included, and the third driving mechanism is used to drive the suction cup group sliding block 21 to move. The third driving mechanism includes a third rack 22, a third gear 23 and a third motor. The third rack 22 is fixed to the side of the base 27, and the third gear 23 is installed at the output end of the third motor. The third rack 22 and the third gear 23 are meshed and connected, and the third motor is fixed to the end of the suction cup group sliding block 21. By controlling the third motor, the suction cup group sliding block 21 can be moved to a desired working position.

[0069] It also includes a fourth driving mechanism, which is used to drive the suction cup assembly 28 to move. The fourth driving mechanism includes a fourth rack 24, a fourth gear 25 and a fourth motor. The fourth rack 24 is fixed to the side of the suction cup assembly sliding block 21, and the fourth gear 25 is fixed to the output end of the third motor. The fourth rack 24 is meshed with the fourth gear 25, and the fourth gear 25 is fixedly connected to the suction cup assembly 28 through a connecting shaft. The suction cup assembly 28 is provided with a traction shaft hole 286 that matches the connecting shaft, and the suction cup assembly sliding block 21 is provided with a horizontal guide hole 212 that matches the traction shaft hole 286. By controlling the fourth motor, the suction cup assembly 28 can be moved to a desired working position.

[0070] like Fig.11 As shown, the suction cup assembly 28 includes a universal suction cup 281, a suction cup telescopic cylinder 283 and a suction cup base 284. The bottom of the suction cup telescopic cylinder 283 is installed in the suction cup base 284 through a telescopic mechanism, and the top of the suction cup telescopic cylinder 283 is provided with a suction cup adsorption air inlet 282 for installing the universal suction cup 281; a guide limit ring 285 is provided on the outside of the suction cup base 284, and a suction cup limit guide groove 213 cooperating with the guide limit ring 285 is provided on the suction cup group sliding block 21.

[0071] like Fig.12 As shown, the telescopic device can be a telescopic cylinder or an electric telescopic rod. The telescopic device can also be a hydraulic telescopic column 5, which includes an upper telescopic rod 52, a middle telescopic rod 53 and a bottom telescopic rod 54. The bottom telescopic rod 54 is provided with a blind hole for installing the middle telescopic rod 53, and the middle telescopic rod 53 is provided with a through hole for installing the upper telescopic rod 52. The extended end of the upper telescopic rod 52 and the fixed end of the bottom telescopic rod 54 are provided with a hinge seat 51.

[0072] An aircraft flexible tooling system and a control method thereof include the following steps: Fig.13 Schematic diagram of the control system:

[0073] S1: First, the three-dimensional model parameters of the wall panel are imported into the industrial software, and then the wall panel and the flexible tooling model are simulated and assembled to obtain the skin pre-assembly digital model;

[0074] S2: Determine the working position coordinates corresponding to all the clamping claws 19 and all the suction cup assemblies 28 through the arrangement of the clamping claws 19 and the suction cup assemblies 28 and the optimization model between the minimum deformation of the skin and the frame;

[0075] In step S2, the optimization model is:

[0076] Minimum deformation of skin and skeleton MIN{S max (X), T max (Y)}Satisfies:

[0077]

[0078] X=(x 1 , x 2 , …, x q );

[0079] Y=(y 1 ,y 2 , …, y p );

[0080] (x u ,y l )∈A; u=1,2,…,q; l=1,2,…,p;

[0081] Where: X is the suction cup positioning method; Y is the clamping method of the claw; m is the number of aircraft shells with different curvatures; S max (X) is the maximum deformation of the skin; T max (Y) is the maximum deformation of the skeleton; S i (X) is the maximum deformation of the skin of the ith aircraft shell; T l (Y) is the maximum deformation of the skeleton of the i-th aircraft shell; A is the feasible design domain of the arrangement of the claws and vacuum suction cups under certain constraints. u is the u-th suction cup positioning method; y l is the first claw positioning mode; q is the number of suction cup arrangement modes; p is the number of claw arrangement modes. S3: According to the working position coordinates of the claw assembly 19 and the suction cup assembly 28, first control the claw assembly sliding block 13 and the suction cup assembly sliding block 21 to move to the corresponding working position, and then control the claw assembly 19 and the suction cup assembly 28 to move to the corresponding working position;

[0082] S4: After the claw assembly 19 and the suction cup assembly 28 move to the working position, the claw assembly 19 is first controlled to clamp the frame to clamp the skin to the position above the suction cup assembly 28, and then the claw assembly 19 is controlled to release the frame, and the suction cup telescopic cylinder 283 is controlled to extend at the same time, and the universal suction cup 281 is adaptively rotated to the tangent adsorption position according to the curvature of the clamped aircraft skin and the adaptive rotation algorithm;

[0083] In step S4, the steps of the adaptive rotation algorithm are as follows:

[0084] S41: interpolating a data point set of the aircraft shell model to be assembled into a smooth two-dimensional curve function;

[0085] Specifically, the aircraft shell to be assembled is divided into several planes by the surface where the track of the suction cup assembly 28 is located, and the shell model point set of each plane is interpolated into a two-dimensional curve function. The obtained two-dimensional curve function is as follows:

[0086]

[0087] where h i =x i -x i-1 ,h i is the distance between the i-1th point and the i-th point; M i-1 is the slope of the i-1th point; M i is the slope of the ith point; y i-1 is the ordinate of the i-1th point; y i is the ordinate of the i-th point; f i (x) is the function after interpolation; x is the coordinate of the coordinate point on the X-axis; y is the coordinate of the coordinate point on the Y-axis; x i-1 is the coordinate of the i-1th shell model point on the X-axis, x i is the coordinate of the i-th shell model point on the X-axis. S42: According to the interpolated two-dimensional curve function, the adaptive rotation angle of the suction cup head on the corresponding track is calculated. The formula for calculating the adaptive rotation angle of the suction cup head is as follows:

[0088]

[0089] Among them, h i =x i -x i-1 ,h i is the distance between the i-1th shell model point and the i-th shell model point; M i-1 is the slope of the i-1th shell model point; M i is the slope of the i-th shell model point; y i-1 is the ordinate of the i-1th shell model point; y i is the ordinate of the i-th shell model point; x is the coordinate of the coordinate point on the X-axis; y is the coordinate of the coordinate point on the Y-axis; y′ is the derivative of the function value of the coordinate point with respect to the X-axis independent variable, and y″ is the second-order derivative of the function value of the coordinate point with respect to the X-axis independent variable.

[0090] S5: After the universal suction cup 281 rotates to the tangential suction position, the suction cup assembly 28 is controlled to start suction and the assembly operation is performed. After receiving the command, the suction cup assembly 28 is controlled to start suction and detect whether there is leakage through the air pressure sensor; if the data of the air pressure sensor is abnormal, there is leakage, then the problem is found from the pre-assembly link and the above process is repeated; if the data of the gas sensor is normal, there is no leakage, and the next assembly operation is performed.

Claims

1. An aircraft flexible tooling system, characterized in that: It comprises a movable frame clamping tool (1) and a plurality of skin clamping tools; The skeleton clamping tool (1) comprises a frame (11) and a plurality of telescopic bracket legs (12) fixed to the bottom of the frame (11); the frame (11) is provided with a plurality of movable groups of claw group sliding blocks (13); each group of the claw group sliding blocks (13) is provided with a plurality of movable claw assemblies (19); The skin clamping tool comprises a machine base (27), on which a plurality of groups of suction cup group sliding blocks (21) are arranged, each group of the suction cup group sliding blocks (21) is provided with a vertical guide hole (211), and a plurality of movable suction cup assemblies (28) are arranged in the vertical guide holes (211).

2. The aircraft flexible tooling system according to claim 1, characterized in that: The skin clamping tool (3) comprises a left skin clamping tool (2), a middle skin clamping tool (3) and a right skin clamping tool (4) of the same structure; the left skin clamping tool (2) and the middle skin clamping tool (3), and the middle skin clamping tool (3) and the right skin clamping tool (4) are hinged via a hinge shaft (6); the bottoms of the left skin clamping tool (2) and the right skin clamping tool (4) are both provided with telescopic devices, and the telescopic devices are used to adjust the angles between the left skin clamping tool (2), the right skin clamping tool (4) and the middle skin clamping tool (3).

3. The aircraft flexible tooling system according to claim 1, characterized in that: The suction cup assembly (28) comprises a universal suction cup (281), a suction cup telescopic cylinder (283) and a suction cup base (284); the bottom of the suction cup telescopic cylinder (283) is installed in the suction cup base (284) through a telescopic mechanism; the top of the suction cup telescopic cylinder (283) is provided with a suction cup adsorption air inlet (282) for installing the universal suction cup (281); the outside of the suction cup base (284) is provided with a guide limit ring (285); and the suction cup assembly sliding block (21) is provided with a suction cup limit guide groove (213) that cooperates with the guide limit ring (285).

4. The aircraft flexible tooling system according to claim 1, characterized in that: The invention also comprises a first driving mechanism, which is used for driving the sliding block (13) of the claw group to move, and the first driving mechanism comprises a first rack (14), a first gear (15) and a first motor, wherein the first rack (14) is arranged at the top of the frame (11), the first gear (15) is arranged at the end of the sliding block (13) of the claw group, the first rack (14) is meshed with the first gear (15), and the first gear (15) is fixed at the output end of the first motor.

5. The aircraft flexible tooling system according to claim 1, characterized in that: The invention also includes a second driving mechanism, which is used to drive the claw assembly (19) to move. The second driving mechanism includes a second rack (110), a second gear (111) and a second motor. The second rack (110) is fixed to the side of the claw group sliding block (13). The claw group sliding block (13) is provided with a sliding bar hole (16) for installing the claw assembly (19). A claw sliding block (17) is fixed to the top of the claw assembly (19) through the sliding bar hole (16). The second gear (111) is installed on the output shaft of the second motor. The second rack (110) is meshed with the second gear (111). The second motor is fixedly connected to the claw sliding block (17).

6. The aircraft flexible tooling system according to claim 1, characterized in that: The machine also includes a third driving mechanism, which is used to drive the suction cup group sliding block (21) to move. The third driving mechanism includes a third rack (22), a third gear (23) and a third motor. The third rack (22) is fixed to the side of the machine base (27), and the third gear (23) is installed at the output end of the third motor. The third rack (22) and the third gear (23) are meshed and connected. The third motor is fixed to the end of the suction cup group sliding block (21).

7. The aircraft flexible tooling system according to claim 1, characterized in that: The invention also comprises a fourth driving mechanism, which is used for driving the suction cup assembly (28) to move, and comprises a fourth rack (24), a fourth gear (25) and a fourth motor, wherein the fourth rack (24) is fixed to the side of the suction cup assembly sliding block (21), and the fourth gear (25) is fixed to the output end of the third motor, the fourth rack (24) is meshed with the fourth gear (25), and the fourth gear (25) is fixedly connected to the suction cup assembly (28) via a connecting shaft, the suction cup assembly (28) is provided with a traction shaft hole (286) matched with the connecting shaft, and the suction cup assembly sliding block (21) is provided with a horizontal guide hole (212) matched with the traction shaft hole (286).

8. A control method for an aircraft flexible tooling system according to any one of claims 1 to 7, characterized in that: The steps include: S1: First, the three-dimensional model parameters of the wall panel are imported into the industrial software, and then the wall panel and the flexible tooling model are simulated and assembled to obtain the skin pre-assembly digital model; S2: determining the working position coordinates corresponding to all the clamping claws (19) and all the suction cup assemblies (28) through the arrangement of the clamping claws (19) and the suction cup assemblies (28), and the optimization model between the minimum deformation of the skin and the frame; S3: According to the working position coordinates of the claw assembly (19) and the suction cup assembly (28), firstly control the claw assembly sliding block (13) and the suction cup assembly sliding block (21) to move to the corresponding working positions, and then control the claw assembly (19) and the suction cup assembly (28) to move to the corresponding working positions; S4: After the claw assembly (19) and the suction cup assembly (28) move to the working position, the claw assembly (19) is first controlled to clamp the frame to clamp the skin to the position above the suction cup assembly (28), and then the claw assembly (19) is controlled to release the frame, and at the same time the suction cup telescopic cylinder (283) is controlled to extend, and the universal suction cup (281) is adaptively rotated to a tangent adsorption position according to the curvature of the clamped aircraft skin and the adaptive rotation algorithm; S5: After the universal suction cup (281) rotates to the tangential suction position, the suction cup assembly (28) is controlled to start suction and perform the assembly operation.

9. The control method of the aircraft flexible tooling system according to claim 8, characterized in that: In step S2, the optimization model is: Minimum deformation of skin and skeleton MIN{S max (X), T max (Y)}Satisfies: X=(x1,x2,...,x q ); Y=(y1,y2,...,y p ); (x u ,y l )∈A;u=1,2,...,q;l=1,2,...,p; Where: X is the suction cup positioning method; Y is the clamping method of the claw; m is the number of aircraft shells with different curvatures; S max (X) is the maximum deformation of the skin; T max (Y) is the maximum deformation of the skeleton; S i (X) is the maximum deformation of the skin of the ith aircraft shell; T l (Y) is the maximum deformation of the skeleton of the i-th aircraft shell; A is the feasible design domain of the arrangement of the claws and vacuum suction cups under certain constraints; x u is the u-th suction cup positioning method; y l is the lth claw positioning method; q is the number of suction cup arrangement methods; p is the number of claw arrangement methods.

10. The aircraft flexible tooling system and control method thereof according to claim 8, characterized in that: In step S4, the steps of the adaptive rotation algorithm are as follows: S41: interpolating a data point set of the aircraft shell model to be assembled into a smooth two-dimensional curve function; Specifically, the aircraft shell to be assembled is divided into a plurality of planes by the surface where the track of the suction cup assembly (28) is located, and the shell model point sets of each plane are interpolated into a two-dimensional curve function. The obtained two-dimensional curve function is as follows: Among them, h i =x i -x i-1 ,h i is the distance between the i-1th shell model point and the i-th shell model point; M i-1 is the slope of the i-1th shell model point; M i is the slope of the i-th shell model point; y i-1 is the ordinate of the i-1th shell model point; y i is the ordinate of the i-th shell model point; f i (x) is the function after interpolation; x is the coordinate of the coordinate point on the X-axis; y is the coordinate of the coordinate point on the Y-axis; x i-1 is the coordinate of the i-1th shell model point on the X-axis, x i is the coordinate of the i-th shell model point on the X-axis. S42: Calculate the adaptive rotation angle of the suction cup head on the corresponding track according to the interpolated two-dimensional curve function. The formula for calculating the adaptive rotation angle of the suction cup head is as follows: Wherein: α is the adaptive rotation angle of the suction cup head; l0 is the coordinate of the center of the curvature circle in the x-direction; h0 is the coordinate of the center of the curvature circle in the y-direction; l1 is the coordinate of the suction cup in the x-direction; R is the radius of the curvature circle of the specified coordinate; L is the length of the suction cup head; x is the coordinate of the coordinate point on the X-axis; y is the coordinate of the coordinate point on the Y-axis; y′ is the derivative of the function value of the coordinate point with respect to the X-axis independent variable, and y″ is the second-order derivative of the function value of the coordinate point with respect to the X-axis independent variable.

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