A method and system for fiber winding path generation, pattern matching and four-axis numerical control post-processing of a variable-pole hole composite pressure vessel

Abstract

The application discloses a method and system for generating, pattern matching and four-axis numerical control post-processing of fiber winding paths of unequal-pole hole composite material pressure containers, and belongs to the technical field of industrial software data processing. The method comprises the following steps: establishing an unequal-pole hole core mold model, independently setting a front-pole hole radius and a rear-pole hole radius; respectively establishing boundary conditions for front and rear heads, independently searching for a sliding coefficient and judging linear stability based on an arc length parameterized ordinary differential equation set and a shooting method; taking a pole hole turning radius and a residence angle as phase modulation parameters, jointly searching for N / k patterns and calculating a coverage rate; converting path points into four-axis winding machine coordinates considering the continuity of head slopes, safety gaps and C-axis postures; performing multi-axis speed planning and generating NC codes in combination with axis speeds, C-axis angular velocities and U-turn decelerations; and integrating path generation, pattern matching and post-processing in a same process and outputting NC programs. The application solves the problem that a single geodesic line is difficult to meet the constraint of different pole holes at two ends, and improves path convergence, pattern closeness and equipment motion adaptability.

Description

Technical Field

[0001] This invention relates to the field of industrial software data processing technology, and in particular to a method and system for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing on pressure vessels made of unequal-polarity composite materials. Background Technology

[0002] Composite material pressure vessels are typically manufactured by continuously impregnating resin with fibers and then winding them onto a mandrel surface. For vessels with equal-radius polar holes, existing technology is relatively mature. The path design can usually be completed based on geodesic relationships, empirical dwell angles, or manual adjustment of the pattern, and a winding path that meets the process requirements can be obtained.

[0003] However, existing methods have significant shortcomings for pressure vessels with unequal pole hole radii. A single geodesic constraint is insufficient to simultaneously satisfy the boundary conditions of two different pole holes, easily leading to situations where one path meets the requirements while the other deviates. Boundary conditions and slip coefficients are typically not established separately for the front and rear heads, resulting in path drift in the head region and unstable fiber orientation near the pole holes. The lack of linkage between pole hole dwell angle, turnaround radius, single-loop phase difference, and N / k pattern can easily cause pattern non-closure, insufficient local coverage, or excessive overlap. Furthermore, the conversion from path points to equipment motion coordinates often equates the mandrel contact point with the feed nozzle position, failing to fully consider head slope, feed nozzle width, safety clearance, and C-axis attitude. Post-processing often only outputs geometric coordinates, without comprehensively considering multi-axis speed, acceleration, and turning deceleration capabilities of the machine tool. This results in fragmented line design, pattern judgment, four-axis post-processing, and NC code verification, with engineering parameter tuning relying on manual experience, making it difficult to form a repeatable software workflow. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing for pressure vessels made of composite materials with unequal polar holes. This addresses the problems in existing technologies where a single geodesic cannot simultaneously satisfy constraints of different polar holes before and after the process, such as path drift of the front and rear end caps, incomplete pattern closure, and insufficient local coverage. By solving for independent non-geodesic solutions for the front and rear end caps and linking polar hole rotation with pattern matching, the path convergence and coverage controllability are improved. Simultaneously, this invention solves the problems of insufficient accuracy in coordinate transformation from path points to four-axis equipment and the lack of comprehensive consideration of multi-axis motion capabilities in post-processing. Through end cap slope compensation, wire feed nozzle width projection, C-axis attitude continuity, and multi-axis speed planning, the output NC program conforms to the actual motion capabilities of the equipment, achieving the integration of line design, pattern matching, and CNC post-processing.

[0005] To achieve the above objectives, this invention provides a method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing on pressure vessels made of unequal-polarity porous composite materials, comprising the following steps: S1. Establish the unequal pole hole mandrel model, and obtain the mandrel geometric parameters, front and rear pole hole parameters, fiber width and equipment post-processing parameters. The mandrel is divided into three sections along the axial direction: front end, cylindrical body and rear end. The mandrel radius is represented by the radius function r(z). The front pole hole radius and the rear pole hole radius are set independently. S2. Establish initial winding angle and turning conditions for the front end and the rear end respectively. Based on the arc length parameterized ordinary differential equation system, use the shooting method or equivalent numerical search method to independently search for the slip coefficient of the front end and the slip coefficient of the rear end, so that the fiber satisfies the tangential turning condition at the corresponding pole hole or folding radius. Compare the obtained slip coefficient with the preset friction coefficient to judge the linear stability. S3. Using the polar hole return radius and dwell angle as phase adjustment parameters, adjust the single-loop circumferential phase difference, search for the N / k pattern based on the single-loop circumferential phase difference, fiber bandwidth, overlap rate and core mold radius, and calculate the coverage rate. S4. Convert the path points {z,r,θ,α} into four-axis winding machine coordinates {A,X,Y,C}, where the A-axis is the cumulative rotation angle of the mandrel, the X-axis is the axial position of the trolley, the Y-axis is the radial position of the wire feed nozzle, and the C-axis is the rotation angle of the wire feed nozzle. When converting the end cap area, consider the mandrel slope, safety clearance, wire feed nozzle width projection, and C-axis attitude continuity. S5. Multi-axis speed planning is performed by combining the speed limits of each axis, the angular velocity limit of the C-axis, the processing time of the NC program block, acceleration planning, and deceleration of the end cap turning around, and NC feed speed and NC code are generated. S6. Integrate path generation, pattern matching, and four-axis CNC post-processing into the same process, perform software visualization verification, and output NC program.

[0006] Preferably, the geometric parameters of the core mold include the cylinder diameter, cylinder length, front end height, and rear end height; the front and rear pole hole parameters include the front pole hole diameter, rear pole hole diameter, front end dwell angle, rear end dwell angle, front end turn-back radius, and rear end turn-back radius. The types of heads include ellipsoidal, hemispherical, isotensional, parabolic, conical, and dish-shaped. For isotensional heads, the head profile is obtained by integrating ordinary differential equations based on grid theory.

[0007] Preferably, the system of ordinary differential equations parameterized by arc length is as follows: ; ; ; ; Where s is the arc length parameter, For axial coordinates, For circumferential angle, For the wrapping angle, The slip coefficient, For normal curvature.

[0008] Preferably, the search for N / k patterns includes: Based on the circumferential phase difference of the target single loop, integers N and k satisfying the flower pattern closure condition are searched, and the expression is: ; ; ; ; in, Let N be the target single-loop circumferential phase difference, N be the number of flower-shaped tangent points, and k be the flower-shaped tangent point offset. For single-step circumferential phase angle, R is the axial step distance, and R is the cylinder radius. B is the effective bandwidth in the circumferential direction, and B is the fiber bandwidth. Minimum wrapping angle, This represents the fiber overlap ratio.

[0009] Preferably, the coordinate transformation formula for the head region is: ; ; ; ; Where m is the head slope factor, z is the mandrel axial coordinate, and r is the mandrel radius. For the wrapping angle, The rate of change of the core mold radius with respect to the axial coordinate. This is the axial reference offset. The tangential direction symbol is used. To ensure a safe clearance between the feed nozzle and the core mold surface. For the width of the feed nozzle, The symbol for the C-axis rotation direction. Let X be the arctangent function in the four quadrants, X be the axial coordinate of the trolley, Y be the radial coordinate of the wire feed nozzle, and C be the rotation angle of the wire feed nozzle.

[0010] Preferably, the C-axis angular velocity limitation uses the C-axis as an angular velocity constraint rather than a spatial displacement constraint, and limits the motion time of the corresponding segment based on the C-axis angular velocity limitation.

[0011] Preferably, multi-axis velocity planning also includes segmented tolerance path simplification in the four-dimensional space of A, X, Y, and C, and templated output of NC programs.

[0012] Preferably, the software visualization verification includes complete line display, front and rear electrode hole detail display, pattern result display, post-processing parameter display, and NC preview.

[0013] Preferably, unequal polar holes refer to the front polar hole radius being different from the rear polar hole radius, with the front end cap and the rear end cap having independent boundary conditions and slip coefficients, and not sharing the same polar hole radius or the same slip coefficient.

[0014] Preferably, a fiber winding path generation, pattern matching, and four-axis CNC post-processing system for pressure vessels made of unequal-polarity composite materials includes: The model building module is used to build a unequal pole hole core mold model, and obtain the core mold geometric parameters, front and rear pole hole parameters, fiber bandwidth and equipment post-processing parameters. The core mold is divided into three sections along the axial direction: front end, cylindrical body and rear end. The core mold radius is represented by the radius function r(z). The front pole hole radius and the rear pole hole radius are set independently. The stability judgment module is used to establish the initial winding angle and turning conditions for the front end and the rear end respectively. Based on the arc length parameterized ordinary differential equation system, the front end slip coefficient and the rear end slip coefficient are independently searched by the shooting method or the equivalent numerical search method to make the fiber meet the tangential turning condition at the corresponding pole hole or folding radius. The obtained slip coefficient is compared with the preset friction coefficient to judge the linear stability. The search calculation module is used to adjust the single-loop circumferential phase difference by using the polar hole return radius and dwell angle as phase adjustment parameters, and to search for the N / k pattern based on the single-loop circumferential phase difference, fiber bandwidth, overlap rate and core mold radius, and to calculate the coverage rate. The coordinate transformation module is used to convert the path point {z,r,θ,α} into the coordinates {A,X,Y,C} of a four-axis winding machine. The A-axis is the cumulative rotation angle of the mandrel, the X-axis is the axial position of the trolley, the Y-axis is the radial position of the wire feed nozzle, and the C-axis is the rotation angle of the wire feed nozzle. When transforming the end cap area, the mandrel slope, safety clearance, wire feed nozzle width projection, and C-axis attitude continuity are taken into account. The synthesis generation module is used to synthesize the speed limits of each axis, the angular velocity limit of the C-axis, the processing time of the NC program block, the acceleration planning, and the deceleration of the end cap turning around to perform multi-axis speed planning, and generate NC feed speed and NC code. The NC program output module integrates path generation, pattern matching, and four-axis CNC post-processing into a single process, performs software visualization verification, and outputs the NC program.

[0015] The advantages and beneficial effects of this invention compared to the prior art are: 1. This invention establishes initial conditions for the front and rear end caps separately and performs non-geodetic solutions independently, which can handle composite pressure vessels with different front and rear polar hole radii. It solves the problem that a single geodesic cannot simultaneously satisfy the polar hole constraints at both ends, and improves the path convergence and polar hole turning stability in the unequal polar hole end cap region.

[0016] 2. This invention uses the polar hole return radius and dwell angle as phase adjustment parameters, so that the single-loop phase difference, fiber bandwidth, overlap rate and N / k pattern are solved in conjunction, which improves the pattern closure and coverage controllability, and avoids insufficient local coverage or excessive overlap.

[0017] 3. Based on the parameterization of arc length, this invention uses the shooting method or equivalent numerical search method to search for the slip coefficient, and compares the obtained slip coefficient with the friction coefficient to determine the stability of the line shape. This reduces the risk of numerical singularity when the winding angle near the pole hole is close to 90°, and ensures the frictional stability of the path.

[0018] 4. When converting path points into A / X / Y / C coordinates of a four-axis winding machine, this invention fully considers the mandrel slope, safety clearance, feed nozzle width projection, and C-axis attitude continuity in the end cap area. It also integrates the speed limits of each axis, the C-axis angular velocity limit, NC program block processing time, acceleration, and turning deceleration to perform multi-axis speed planning, so that the output program conforms to the motion capability of the actual winding equipment. At the same time, it integrates path generation, pattern matching, four-axis CNC post-processing, and visualization verification into the same process, reducing the cost of repeated manual parameter adjustments.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-polarity porosity composite material according to an embodiment of the present invention. Figure 2 This is a structural diagram of a fiber winding path generation, pattern matching, and four-axis CNC post-processing system for a pressure vessel made of unequal-polarity porous composite material according to an embodiment of the present invention. Figure 3 This is an overview interface diagram of the LX-01 unequal polarity hole line design according to an embodiment of the present invention; Figure 4 This is a complete line graph showing the MAX loop in an embodiment of the present invention; Figure 5 This is an interface diagram showing the stability judgment, winding angle distribution, and flower pattern parameters of an embodiment of the present invention; Figure 6 This is a configuration interface diagram of a four-axis post-processing machine according to an embodiment of the present invention; Figure 7This is a screenshot of the NC code preview and post-processing statistics interface in an embodiment of the present invention. Detailed Implementation

[0021] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] like Figure 1 As shown, this invention provides a method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing on pressure vessels made of unequal-pole porous composite materials, including the following steps: S1. Establish the unequal pole hole mandrel model, and obtain the mandrel geometric parameters, front and rear pole hole parameters, fiber width and equipment post-processing parameters. The mandrel is divided into three sections along the axial direction: front end, cylindrical body and rear end. The mandrel radius is represented by the radius function r(z). The front pole hole radius and the rear pole hole radius are set independently. S2. Establish initial winding angle and turning conditions for the front end and the rear end respectively. Based on the arc length parameterized ordinary differential equation system, use the shooting method or equivalent numerical search method to independently search for the slip coefficient of the front end and the slip coefficient of the rear end, so that the fiber satisfies the tangential turning condition at the corresponding pole hole or folding radius. Compare the obtained slip coefficient with the preset friction coefficient to judge the linear stability. S3. Using the polar hole return radius and dwell angle as phase adjustment parameters, adjust the single-loop circumferential phase difference, search for the N / k pattern based on the single-loop circumferential phase difference, fiber bandwidth, overlap rate and core mold radius, and calculate the coverage rate. S4. Convert the path points {z,r,θ,α} into four-axis winding machine coordinates {A,X,Y,C}, where the A-axis is the cumulative rotation angle of the mandrel, the X-axis is the axial position of the trolley, the Y-axis is the radial position of the wire feed nozzle, and the C-axis is the rotation angle of the wire feed nozzle. When converting the end cap area, consider the mandrel slope, safety clearance, wire feed nozzle width projection, and C-axis attitude continuity. S5. Multi-axis speed planning is performed by combining the speed limits of each axis, the angular velocity limit of the C-axis, the processing time of the NC program block, acceleration planning, and deceleration of the end cap turning around, and NC feed speed and NC code are generated. S6. Integrate path generation, pattern matching, and four-axis CNC post-processing into the same process, perform software visualization verification, and output NC program.

[0024] Preferably, the geometric parameters of the core mold include the cylinder diameter, cylinder length, front end height, and rear end height; the front and rear pole hole parameters include the front pole hole diameter, rear pole hole diameter, front end dwell angle, rear end dwell angle, front end turn-back radius, and rear end turn-back radius. The types of heads include ellipsoidal, hemispherical, isotensional, parabolic, conical, and dish-shaped. For isotensional heads, the head profile is obtained by integrating ordinary differential equations based on grid theory.

[0025] Preferably, the system of ordinary differential equations parameterized by arc length is as follows: ; ; ; ; Where s is the arc length parameter, For axial coordinates, For circumferential angle, For the wrapping angle, The slip coefficient, For normal curvature.

[0026] Preferably, the search for N / k patterns includes: Based on the circumferential phase difference of the target single loop, integers N and k satisfying the flower pattern closure condition are searched, and the expression is: ; ; ; ; in, Let N be the target single-loop circumferential phase difference, N be the number of flower-shaped tangent points, and k be the flower-shaped tangent point offset. For single-step circumferential phase angle, R is the axial step distance, and R is the cylinder radius. B is the effective bandwidth in the circumferential direction, and B is the fiber bandwidth. Minimum wrapping angle, This represents the fiber overlap ratio.

[0027] Preferably, the coordinate transformation formula for the head region is: ; ; ; ; Where m is the head slope factor, z is the mandrel axial coordinate, and r is the mandrel radius. For the wrapping angle, The rate of change of the core mold radius with respect to the axial coordinate. This is the axial reference offset. The tangential direction symbol is used. To ensure a safe clearance between the feed nozzle and the core mold surface. For the width of the feed nozzle, The symbol for the C-axis rotation direction. Let X be the arctangent function in the four quadrants, X be the axial coordinate of the trolley, Y be the radial coordinate of the wire feed nozzle, and C be the rotation angle of the wire feed nozzle.

[0028] Preferably, the C-axis angular velocity limitation uses the C-axis as an angular velocity constraint rather than a spatial displacement constraint, and limits the motion time of the corresponding segment based on the C-axis angular velocity limitation.

[0029] Preferably, multi-axis velocity planning also includes segmented tolerance path simplification in the four-dimensional space of A, X, Y, and C, and templated output of NC programs.

[0030] Preferably, the software visualization verification includes complete line display, front and rear electrode hole detail display, pattern result display, post-processing parameter display, and NC preview.

[0031] Preferably, unequal polar holes refer to the front polar hole radius being different from the rear polar hole radius, with the front end cap and the rear end cap having independent boundary conditions and slip coefficients, and not sharing the same polar hole radius or the same slip coefficient.

[0032] Preferred, such as Figure 2 As shown, a fiber winding path generation, pattern matching, and four-axis CNC post-processing system for pressure vessels made of unequal-polarity porous composite materials includes: The model building module is used to build a unequal pole hole core mold model, and obtain the core mold geometric parameters, front and rear pole hole parameters, fiber bandwidth and equipment post-processing parameters. The core mold is divided into three sections along the axial direction: front end, cylindrical body and rear end. The core mold radius is represented by the radius function r(z). The front pole hole radius and the rear pole hole radius are set independently. The stability judgment module is used to establish the initial winding angle and turning conditions for the front end and the rear end respectively. Based on the arc length parameterized ordinary differential equation system, the front end slip coefficient and the rear end slip coefficient are independently searched by the shooting method or the equivalent numerical search method to make the fiber meet the tangential turning condition at the corresponding pole hole or folding radius. The obtained slip coefficient is compared with the preset friction coefficient to judge the linear stability. The search calculation module is used to adjust the single-loop circumferential phase difference by using the polar hole return radius and dwell angle as phase adjustment parameters, and to search for the N / k pattern based on the single-loop circumferential phase difference, fiber bandwidth, overlap rate and core mold radius, and to calculate the coverage rate. The coordinate transformation module is used to convert the path point {z,r,θ,α} into the coordinates {A,X,Y,C} of a four-axis winding machine. The A-axis is the cumulative rotation angle of the mandrel, the X-axis is the axial position of the trolley, the Y-axis is the radial position of the wire feed nozzle, and the C-axis is the rotation angle of the wire feed nozzle. When transforming the end cap area, the mandrel slope, safety clearance, wire feed nozzle width projection, and C-axis attitude continuity are taken into account. The synthesis generation module is used to synthesize the speed limits of each axis, the angular velocity limit of the C-axis, the processing time of the NC program block, the acceleration planning, and the deceleration of the end cap turning around to perform multi-axis speed planning, and generate NC feed speed and NC code. The NC program output module integrates path generation, pattern matching, and four-axis CNC post-processing into a single process, performs software visualization verification, and outputs the NC program.

[0033] The following is a verification using a specific embodiment.

[0034] The following uses a set of LX-01 unequal polarity hole profiles completed by the present invention as an example to further illustrate the technical solution of the present invention.

[0035] S1. Establish the unequal-pole hole mandrel model and obtain parameters. In the software parameter input interface, set the mandrel cylinder outer diameter D=255mm, cylindrical body length L=1180mm, front pole hole diameter d1=90mm (large pole hole end), rear pole hole diameter d2=42mm (small pole hole end), front end cap height h1=77mm (front ellipsoidal end cap), rear end cap height h2=83mm (rear ellipsoidal end cap), fiber width B=34.5mm, friction coefficient μ=0.3, front end dwell angle 16°, rear end dwell angle 0°, front end return radius 65.1mm, rear end return radius 40.5mm. The mandrel is divided into three sections along the z-axis: front end cap, cylindrical body, and rear end cap. The front pole hole radius r01 and rear pole hole radius r02 are set independently, and the mandrel profile is described by the radius function r(z). Figure 3 As shown, the software interface overview displays the LX-01 unequal-pole hole profile design environment after the above parameters are input.

[0036] S2. Independent Non-Geodesic Solution and Stability Judgment for Front and Rear Ends. Initial winding angles and turning conditions are established for the front and rear end caps separately, without sharing the same pole hole radius or slip coefficient. The path integral uses the arc length parameter s, and the state variables include the axial coordinate z(s), circumferential angle θ(s), and winding angle α(s). The slip coefficient λ1 is searched for the front end using a shooting method or equivalent numerical search method, and the slip coefficient λ2 is searched independently for the rear end cap, ensuring that the fiber satisfies the tangential turning condition near the corresponding pole hole or foldback radius. The calculated front slip coefficient λ1 = 0.0044 and the rear slip coefficient λ2 = 0.0038, both less than the preset friction coefficient μ = 0.3. Therefore, the linear shape is determined to satisfy the frictional stability constraint, and the path converges and the pole hole turning is stable in the front and rear end cap regions. Figure 5 As shown, the software interface displays the stability judgment results, winding angle distribution, and slip coefficient comparison.

[0037] S3. Pole hole orientation phase adjustment, pattern matching, and coverage calculation. The front turnaround radius (65.1 mm), rear turnaround radius (40.5 mm), and front and rear dwell angles were used as phase adjustment parameters to adjust the circumferential phase difference of a single loop. Based on the fiber bandwidth B = 34.5 mm, overlap rate, and mandrel radius, the N / k pattern was found to be 4 / 1, with a single loop phase difference of approximately 93.09°, an effective circumferential bandwidth of approximately 36.38 mm, a coverage loop count of 6 × 4 = 24, and a coverage rate of approximately 109.0%. This result indicates that the path phase, fiber bandwidth, and pattern period were solved in conjunction with the linear design process, resulting in a closed pattern and controllable coverage.

[0038] S4. Four-axis coordinate transformation. The path points {z,r,θ,α} are converted to four-axis winding machine coordinates {A,X,Y,C}. In the end cap region, the transformation formula fully considers the projection compensation of the mandrel slope dr / dz, clearance, nozzle width, and C-axis attitude continuity. For example... Figure 6 As shown, in the configuration interface of the four-axis post-processing machine, the A-axis is configured as the cumulative rotation angle of the mandrel, the X-axis is the axial position of the carriage, the Y-axis is the radial position of the wire feed nozzle, and the C-axis is the rotation angle of the wire feed nozzle. The motion relationship of each axis and the end cap slope compensation parameters are all set in the configuration interface.

[0039] S5. Multi-axis speed planning and path simplification. Speed ​​planning is performed by integrating the speed limits of each axis, the angular velocity limit of the C-axis (treating the C-axis as an angular velocity constraint rather than a spatial displacement constraint), NC program block processing time, acceleration planning, and head turning deceleration. The planned range of feed rate F is 1.0~200.0 mm / s. Segmented tolerance path simplification is performed in the four-dimensional space of A / X / Y / C, and the NC program is output in a template format.

[0040] S6, NC code generation and visual verification. Integrates path generation, pattern matching, and four-axis CNC post-processing into a single workflow. For example... Figure 4 As shown, the software displays the complete line shape after the MAX loop, allowing for intuitive observation of the fiber layup trajectory when the front and rear electrode holes are unequal. For example... Figure 7 As shown, the NC code preview and post-processing statistics interface displays: 24 cycle layers, 456 cycle points, a total rotation angle of approximately 38209.6°, approximately 168 NC lines, and an estimated winding time of approximately 2 minutes. Through comprehensive visualization verification using complete line type display, front and rear electrode hole details, pattern results, post-processing parameters, and the NC preview, it was confirmed that the unequal electrode hole line type is geometrically executable and can run stably on the equipment. Finally, the NC program is output to the four-axis winding machine.

[0041] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing on pressure vessels made of unequal-pole porous composite materials, characterized in that... Includes the following steps: S1. Establish the unequal pole hole mandrel model, and obtain the mandrel geometric parameters, front and rear pole hole parameters, fiber width and equipment post-processing parameters. The mandrel is divided into three sections along the axial direction: front end, cylindrical body and rear end. The mandrel radius is represented by the radius function r(z). The front pole hole radius and the rear pole hole radius are set independently. S2. Establish initial winding angle and turning conditions for the front end and the rear end respectively. Based on the arc length parameterized ordinary differential equation system, use the shooting method or equivalent numerical search method to independently search for the slip coefficient of the front end and the slip coefficient of the rear end, so that the fiber satisfies the tangential turning condition at the corresponding pole hole or folding radius. Compare the obtained slip coefficient with the preset friction coefficient to judge the linear stability. S3. Using the polar hole return radius and dwell angle as phase adjustment parameters, adjust the single-loop circumferential phase difference, search for the N / k pattern based on the single-loop circumferential phase difference, fiber bandwidth, overlap rate and core mold radius, and calculate the coverage rate. S4. Convert the path points {z,r,θ,α} into four-axis winding machine coordinates {A,X,Y,C}, where the A-axis is the cumulative rotation angle of the mandrel, the X-axis is the axial position of the trolley, the Y-axis is the radial position of the wire feed nozzle, and the C-axis is the rotation angle of the wire feed nozzle. When converting the end cap area, consider the mandrel slope, safety clearance, wire feed nozzle width projection, and C-axis attitude continuity. S5. Multi-axis speed planning is performed by combining the speed limits of each axis, the angular velocity limit of the C-axis, the processing time of the NC program block, acceleration planning, and deceleration of the end cap turning around, and NC feed speed and NC code are generated. S6. Integrate path generation, pattern matching, and four-axis CNC post-processing into the same process, perform software visualization verification, and output NC program.

2. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 1, characterized in that, In S1, the geometric parameters of the core mold include the cylinder diameter, cylinder length, front end height, and rear end height; the parameters of the front and rear pole holes include the front pole hole diameter, rear pole hole diameter, front end dwell angle, rear end dwell angle, front end turn-back radius, and rear end turn-back radius. The head types include ellipsoidal, hemispherical, isotensional, parabolic, conical, and dish-shaped; for isotensional heads, the head profile is obtained by integrating ordinary differential equations based on grid theory.

3. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 2, characterized in that, In S2, the set of arc-length parameterized ordinary differential equations is as follows: ； ； ； ； Where s is the arc length parameter, For axial coordinates, For circumferential angle, For the wrapping angle, The slip coefficient, For normal curvature.

4. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 3, characterized in that, In S3, the search for N / k patterns includes: Based on the circumferential phase difference of the target single loop, integers N and k satisfying the flower pattern closure condition are searched, and the expression is: ； ； ； ； in, Let N be the target single-loop circumferential phase difference, N be the number of flower-shaped tangent points, and k be the flower-shaped tangent point offset. For single-step circumferential phase angle, R is the axial step distance, and R is the cylinder radius. B is the effective bandwidth in the circumferential direction, and B is the fiber bandwidth. Minimum wrapping angle, This represents the fiber overlap ratio.

5. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 4, characterized in that... In S4, the coordinate transformation formula for the head region is: ； ； ； ； Where m is the head slope factor, z is the mandrel axial coordinate, and r is the mandrel radius. For the wrapping angle, The rate of change of the core mold radius with respect to the axial coordinate. This is the axial reference offset. The tangential direction symbol is used. To ensure a safe clearance between the feed nozzle and the core mold surface. For the width of the feed nozzle, The symbol for the C-axis rotation direction. Let X be the arctangent function in the four quadrants, X be the axial coordinate of the trolley, Y be the radial coordinate of the wire feed nozzle, and C be the rotation angle of the wire feed nozzle.

6. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 5, characterized in that, In S5, the C-axis angular velocity limitation uses the C-axis as an angular velocity constraint rather than a spatial displacement constraint, and limits the motion time of the corresponding segment based on the C-axis angular velocity limitation.

7. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 6, characterized in that, In S5, the multi-axis velocity planning also includes segmented tolerance path simplification in the four-dimensional space of A, X, Y, and C, and templated output of the NC program.

8. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 7, characterized in that, In S6, the software visualization verification includes complete line display, front and rear electrode hole detail display, pattern result display, post-processing parameter display, and NC preview.

9. The method for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing of a pressure vessel made of unequal-pole porous composite material according to claim 8, characterized in that, The unequal polar holes refer to the front polar hole radius being different from the rear polar hole radius. The front end cap and the rear end cap each have independent boundary conditions and slip coefficients, and do not share the same polar hole radius or the same slip coefficient.

10. A system for generating fiber winding paths, matching patterns, and performing four-axis CNC post-processing on pressure vessels made of unequal-pole porous composite materials, characterized in that... include: The model building module is used to build a unequal pole hole core mold model, and obtain the core mold geometric parameters, front and rear pole hole parameters, fiber bandwidth and equipment post-processing parameters. The core mold is divided into three sections along the axial direction: front end, cylindrical body and rear end. The core mold radius is represented by the radius function r(z). The front pole hole radius and the rear pole hole radius are set independently. The stability judgment module is used to establish the initial winding angle and turning conditions for the front end and the rear end respectively. Based on the arc length parameterized ordinary differential equation system, the front end slip coefficient and the rear end slip coefficient are independently searched by the shooting method or the equivalent numerical search method to make the fiber meet the tangential turning condition at the corresponding pole hole or folding radius. The obtained slip coefficient is compared with the preset friction coefficient to judge the linear stability. The search calculation module is used to adjust the single-loop circumferential phase difference by using the polar hole return radius and dwell angle as phase adjustment parameters, and to search for the N / k pattern based on the single-loop circumferential phase difference, fiber bandwidth, overlap rate and core mold radius, and to calculate the coverage rate. The coordinate transformation module is used to convert the path point {z,r,θ,α} into the coordinates {A,X,Y,C} of a four-axis winding machine. The A-axis is the cumulative rotation angle of the mandrel, the X-axis is the axial position of the trolley, the Y-axis is the radial position of the wire feed nozzle, and the C-axis is the rotation angle of the wire feed nozzle. When transforming the end cap area, the mandrel slope, safety clearance, wire feed nozzle width projection, and C-axis attitude continuity are taken into account. The synthesis generation module is used to synthesize the speed limits of each axis, the angular velocity limit of the C-axis, the processing time of the NC program block, the acceleration planning, and the deceleration of the end cap turning around to perform multi-axis speed planning, and generate NC feed speed and NC code. The NC program output module integrates path generation, pattern matching, and four-axis CNC post-processing into a single process, performs software visualization verification, and outputs the NC program.

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