Method and device for solving the trajectory of a toroidal braided mandrel considering transient processes
By establishing a three-dimensional model of the mandrel and considering transient processes, the convergence zone state and weaving speed during the weaving process are calculated, generating an accurate mandrel traction trajectory. This solves the problem of discrepancies between the weaving effect and the design target in traditional methods, and improves the weaving quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG UNIV
- Filing Date
- 2023-11-20
- Publication Date
- 2026-07-24
AI Technical Summary
Existing technologies do not fully consider the influence of transient processes when weaving composite material components, resulting in significant differences between the weaving effect and the design target. This is especially true for weaving parts with complex shapes and structures, where the mandrel traction trajectory calculated by traditional methods is not accurate enough.
By establishing a three-dimensional model of the mandrel, extracting the centerline and shape parameters, calculating the convergence zone state and weaving speed during the weaving process, and generating a mandrel traction trajectory that considers the transient process, the weaving angle and convergence zone state are ensured to meet the design objectives.
It improves weaving quality, generates more precise traction tracks, adapts to the weaving needs of complex shapes and structures, and enhances the accuracy of the weaving effect.
Smart Images
Figure CN117454661B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of textile weaving technology, and particularly relates to a method and apparatus for solving the traction trajectory of a ring-shaped weaving mandrel considering transient processes. Background Technology
[0002] Circular braiding is a braiding method used to prepare three-dimensional braided structures, primarily for weaving tubular components. Before braiding, a mandrel of the same shape is first fabricated according to the designed fabric shape. During braiding, the yarns interweave and gradually attach to the surface of the mandrel, forming a three-dimensional braid. After braiding, resin is injected to achieve curing, resulting in a three-dimensional braided composite material component. Three-dimensional braided composite components possess integral molding processing characteristics and excellent mechanical properties, finding applications in aerospace, industrial production, and medical healthcare.
[0003] The mechanical properties of three-dimensional braided composite components are primarily influenced by their fabric geometry. Therefore, specific requirements are set for fabric geometry parameters such as the braiding angle during component design. During the braiding process, geometric features such as the braiding angle are mainly determined by process parameters such as the braiding machine speed and the mandrel traction trajectory. Since the braiding machine speed is typically not adjusted after being determined, the control of the fabric geometry is primarily achieved by adjusting the mandrel traction trajectory. When process parameters change, they first affect the convergence zone state, and changes in the convergence zone state further affect the fabric geometry. Therefore, adjusting the fabric geometry by modifying process parameters involves a transient process with nonlinearity and hysteresis. Traditional methods for solving the mandrel traction trajectory do not adequately consider this transient process. For simple circular tube braided components, the impact is not significant, but as the shape and structure of braided components become increasingly complex, the influence of the transient process becomes more prominent. The traction trajectory obtained using traditional methods may result in a significant difference between the actual braiding effect and the design target. Therefore, in order to solve the above problems, it is necessary to propose a method for solving the traction trajectory of the annular braided mandrel that considers the transient process, so as to overcome the defects of the existing methods. Summary of the Invention
[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method and apparatus for solving the traction trajectory of a circular knitting mandrel that considers transient processes. Based on the shape of the mandrel and the pre-designed fabric geometry, this invention calculates the traction trajectory of the mandrel during the knitting process and considers the influence of transient effects during modeling, resulting in a more accurate traction trajectory and improved knitting quality.
[0005] The objective of this invention is achieved through the following technical solution: a method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, comprising the following steps:
[0006] (1) Determine the three-dimensional model of the mandrel and extract the centerline, shape, and size parameters of the mandrel;
[0007] (2) Based on the extracted mandrel parameter data and the target geometry of the fabric, calculate the convergence state at each stage of the weaving process;
[0008] (3) Based on the convergence zone state and the target geometry of the fabric, calculate the weaving speed at each stage of the weaving process under a given weaving machine speed.
[0009] (4) Generate the mandrel traction trajectory based on the mandrel shape, convergence zone state and weaving speed.
[0010] Furthermore, the extraction of the centerline, shape, and size parameters of the mandrel specifically involves: dividing the mandrel evenly into m segments to generate m+1 cross-sections, including the first end face and the last end face; the end furthest from the braiding machine is the first end of the mandrel; the first cross-section is the first end face;
[0011] For each section T i Calculate the coordinates of its center point P. i The sampling points of the mandrel centerline are obtained, and connecting all the sampling points gives the mandrel centerline.
[0012] For each section T i Calculate its unit normal vector n i Circumference c i Equivalent radius r i Equivalent cone angle γ i This allows us to obtain the shape and size parameters of each position on the mandrel.
[0013] Furthermore, the target geometry of the fabric is represented by the target weave angle, with a target weave angle α set at each mandrel cross-section. i The convergence region state is determined by the convergence region length h. i Angle θ with the convergence region i The relationship between the target braiding angle, mandrel shape, convergence zone length, and convergence zone angle is described below:
[0014]
[0015]
[0016] Where, r i γ represents the equivalent radius of the i-th section. i R represents the equivalent cone angle of the i-th section. g Indicates the radius of the guide ring.
[0017] Furthermore, the rotational speed of the braiding machine is equal to the sum of the braiding angular velocity and the rate of change of the angle between the braiding and convergence zones, where the braiding angular velocity ω... b,i The calculation formula is as follows:
[0018]
[0019] Where ω represents the knitting machine speed, θ i Let Δθ represent the angle between the convergence regions of the i-th cross section. i =θ i+1 -θ i , Δl i γ represents the distance between the i-th cross section and the (i+1)-th cross section. i Let α represent the equivalent cone angle of the i-th section. i This represents the target weave angle of the i-th section.
[0020] Furthermore, the weaving travel speed v b,i The calculation formula is as follows:
[0021]
[0022] Where, ω b,i α represents the weaving angular velocity of the i-th section. i This represents the target weave angle of the i-th section.
[0023] Furthermore, the mandrel traction trajectory is described by the position, attitude, and traction speed of the center point TCP of the robotic arm end tool; the TCP coincides with the center point of the mandrel's first end face.
[0024] Furthermore, the traction trajectory consists of a series of trajectory sampling points Q i and the corresponding traction speed v at each point i express;
[0025] At the trajectory sampling points, when the weaving proceeds to the mandrel section T i At this point, by rotating and translating the mandrel, the normal direction of the cross section is aligned with the direction of the braiding machine's central axis. Simultaneously, the center point of the cross section lies on the braiding machine's central axis, and its distance to the guide ring is equal to the length of the convergence zone. The TCP pose at this moment is calculated and used as the trajectory sampling point Q. i .
[0026] Furthermore, the traction speed v i The sum of the weaving speed and the rate of change of the convergence zone length is calculated using the following formula:
[0027]
[0028] Among them, v b,i Δl represents the weaving speed of the i-th section. iΔh represents the distance between the i-th cross section and the (i+1)-th cross section. i Δt represents the change in the length of the convergence zone during the weaving process from the i-th section to the (i+1)-th section. i This represents the time elapsed from the i-th section to the (i+1)-th section during the weaving process.
[0029] The present invention also provides a device for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, comprising one or more processors for implementing the above-described method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes.
[0030] The present invention also provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, is used to implement the above-described method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes.
[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: by analyzing the transient process of weaving, the relationship between weaving process parameters, convergence zone state and fabric geometry is established, and this relationship is used to solve the mandrel traction trajectory, making the solved mandrel traction trajectory more accurate and thus improving weaving quality. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0033] Figure 1 A schematic diagram of a circular weaving method provided in an embodiment of the present invention;
[0034] Figure 2 This is a schematic diagram of a single yarn weaving model;
[0035] Figure 3 A flowchart illustrating a method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, provided in an embodiment of the present invention;
[0036] Figure 4 This is a schematic diagram of mandrel parameter extraction provided in an embodiment of the present invention;
[0037] Figure 5 A schematic diagram of an equivalent frustum model of a mandrel segment provided in an embodiment of the present invention;
[0038] Figure 6 A schematic diagram defining the weave angle;
[0039] Figure 7A schematic diagram of the convergence region model;
[0040] Figure 8 This is a schematic diagram showing the relationship between weaving angular velocity and weaving travel speed.
[0041] Figure 9 This is a schematic diagram of the mandrel's pose.
[0042] Figure 10 This is a hardware structure diagram provided for an embodiment of the present invention. Detailed Implementation
[0043] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.
[0044] The present invention will now be described in detail with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementations can be combined with each other.
[0045] The schematic diagram of the circular weaving involved in this invention is as follows: Figure 1 As shown, a simplified schematic diagram of its single yarn weaving model is as follows: Figure 2 As shown. Its main components include a mandrel, guide rings, yarn, a braiding machine, and yarn carriers. The mandrel is held by a robotic arm at its head. The yarn is drawn from the yarn carrier on the braiding machine, passes through the guide ring, and is fixed to the head of the mandrel. During braiding, the two sets of yarn carriers on the braiding machine move in uniform circular motions clockwise and counterclockwise, respectively. The mandrel moves along the axial direction of the braiding machine under the traction of the robotic arm, and the yarn follows its movement, achieving interlacing and gradually attaching to the surface of the mandrel to form a three-dimensional braid. During the braiding process, the contact point between the yarn and the guide ring is called the guide point, and the boundary point between the attached and unattached yarn is called the braiding point, i.e., the position where braiding is taking place. The plane where the braiding point is located is called the braiding plane, and the area between the braiding plane and the guide ring is called the convergence zone.
[0046] Establish a world coordinate system {x} with the center point of the knitting machine as the origin. g ,y g ,z g}, establish a tool coordinate system {x} with the center point TCP of the robotic arm's end effector as the origin. t ,y t ,z tDuring the weaving process, the mandrel is held and pulled by a robotic arm; therefore, the final calculated traction trajectory is described using the position, orientation, and traction speed of the TCP (Cyclic Cross-Traction Tool). To facilitate subsequent calculations, the center point of the mandrel's first end face is ensured to coincide with the origin of the tool coordinate system when the mandrel is held, and the normal direction of the mandrel's first end face is aligned with the z-axis of the tool coordinate system. g Axis coincidence. The shape of the spindle is described using the tool coordinate system.
[0047] Figure 3 This is a flowchart illustrating a method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, according to the present invention. (Reference) Figure 3 The method of the present invention includes the following steps:
[0048] (1) Determine the three-dimensional model of the mandrel and extract the centerline, shape, and size parameters of the mandrel;
[0049] In one embodiment, extracting the centerline and shape and size parameters of the mandrel specifically involves: dividing the mandrel into m segments to generate m+1 cross-sections, including the first end face and the last end face; the end furthest from the braiding machine is the first end of the mandrel; the first cross-section is the first end face;
[0050] For each section T i Calculate the coordinates of its center point P. i The sampling points of the mandrel centerline are obtained, and connecting all the sampling points gives the mandrel centerline.
[0051] For each section T i Calculate its unit normal vector n i Circumference c i Equivalent radius r i Equivalent cone angle γ i This allows us to obtain the shape and size parameters of each position on the mandrel.
[0052] like Figure 4 As shown, the centerline of the mandrel is represented by a set of discrete sampling points. To extract the centerline and other relevant parameters, the mandrel model is first uniformly divided into m segments, denoted as S. i Let i = 1, ..., m, and obtain m+1 cross sections including the first and last end faces, denoted as T. i Let i = 1, ..., m+1. Calculate the center point coordinates, unit normal vector, and perimeter of each section in sequence. Section T i The center point is denoted as P. i The unit normal vector is denoted as n. i The perimeter is denoted as c. i Among them, P i =[x t,i ,y t,i ,z t,i ], x t,i ,yt,i ,z t,i Center point P i The coordinate values in the tool coordinate system. When using the robotic arm to hold the mandrel, ensure that P1 = [0,0,0] and n1 = [0,0,1].
[0053] The calculated center point of the cross-section is the centerline sampling point. Connecting all the center points of the cross-section sequentially forms the mandrel centerline. Adjacent centerline sampling points P i With P i+1 The distance between them is denoted as Δl i The calculation formula is as follows:
[0054] Δl i =|P i+1 -P i | (1)
[0055] Section T i The equivalent radius is denoted as r. i The calculation formula is as follows:
[0056]
[0057] like Figure 5 As shown, each segment of the mandrel S after division i It can be approximated as a frustum of a cone. For the frustum S... i The radii of its two end faces (i.e., the i-th section and the (i+1)-th section) are r respectively. i and r i+1 The height is Δl i Its cone angle is denoted as γ. 0,i The calculation formula is as follows:
[0058]
[0059] Then, the cross section T can be calculated. i The equivalent cone angle γ at the location i The calculation formula is as follows:
[0060]
[0061] (2) Based on the extracted mandrel parameter data and the target geometry of the fabric, calculate the convergence zone state at each stage of the weaving process.
[0062] The target geometry of the fabric is represented by the target knitting angle. Different locations on the mandrel surface can have different target knitting angles. The knitting angle is defined as the angle between the tangent of the yarn at that location and the projection of the mandrel centerline onto that location, such as... Figure 6 As shown. Section T i The size of the target weaving angle at that location is denoted as α. i .
[0063] The process by which fabric geometry transitions from one stable state to another is called a transient process. Changes in process parameters such as mandrel traction speed and weaving machine speed, as well as changes in mandrel shape, can all cause transient processes. During weaving, the fabric geometry can be adjusted by changing process parameters to conform to design goals. It should be noted that when process parameters change, they do not directly affect the fabric geometry, but rather first affect the convergence zone state, and changes in the convergence zone state further affect the fabric geometry. Due to the existence of the convergence zone, the nonlinearity of the transient process is enhanced, making the relationship between process parameters and weaving effect more complex. Therefore, to improve the accuracy of mandrel traction trajectory calculation, the influence of the transient process must be considered. The influence of the transient process is mainly due to changes in the convergence zone state; therefore, the transient process can be analyzed by calculating the convergence zone state.
[0064] The convergence region state is described by two parameters: the convergence region length h and the convergence region angle θ. Figure 7 As shown. The convergence zone length refers to the distance between the knitting point and the guide ring, and the convergence zone angle refers to the angle between the knitting point and the guide point relative to the mandrel centerline. Within the convergence zone, the yarn is modeled as a straight line, tangent to the mandrel at the knitting point.
[0065] Based on the geometric relationships during the weaving process, the relationships between the target weaving angle, mandrel shape, convergence zone length, and convergence zone angle can be obtained, as shown in the following formula:
[0066]
[0067]
[0068] Among them, R g Let r represent the guide ring radius, r represent the mandrel equivalent radius, γ represent the equivalent cone angle, and α represent the target weaving angle. At any given moment during the weaving process, r and γ, which characterize the mandrel shape, are fixed values. To ensure that the actual weaving angle equals the target weaving angle, it is necessary to adjust the length of the convergence zone and the angle between the convergence zones. According to equation (5), the weaving progress to section T can be calculated. i The length of the convergence region h at time t is 1. i :
[0069]
[0070] According to equation (6), the angle θ of the convergence region can be obtained at this time. i :
[0071]
[0072] (3) Based on the convergence zone state and the target geometry of the fabric, calculate the weaving speed at each stage of the weaving process under a given weaving machine speed.
[0073] The velocity of the knitting point moving on the mandrel surface is decomposed into knitting angular velocity and knitting travel speed, such as Figure 8 As shown. Knitting angular velocity refers to the angular velocity of the knitting point rotating around the center line during the knitting process, denoted as ω. b The knitting travel speed refers to the speed at which the knitting point moves along the center line during the knitting process, denoted as v. b To ensure that the actual knitting angle equals the target knitting angle, the knitting angular velocity and the knitting travel speed should satisfy the following relationship:
[0074]
[0075] During weaving, the weaving machine moves at a constant speed. Due to the influence of transient processes, the speed ω of the weaving machine and the weaving angular velocity ω b They are not always equal. The knitting machine speed ω is equal to the sum of the knitting angular velocity and the rate of change of the angle between the knitting and convergence zones:
[0076]
[0077] Combining equation (9), we can solve for the weaving process up to section T. i At that time, after considering transient effects, the weaving angular velocity ω b,i for:
[0078]
[0079] Where ω represents the knitting machine speed, θ i Let Δθ represent the angle between the convergence regions of the i-th cross section. i =θ i+1 -θ i , Δl i γ represents the distance between the i-th cross section and the (i+1)-th cross section. i Let α represent the equivalent cone angle of the i-th section. i This represents the target weave angle of the i-th section.
[0080] At this point, the weaving speed needs to be matched with the weaving angular velocity so that the actual weaving angle is equal to the target weaving angle. According to equation (9), the weaving speed v can be obtained. b,i for:
[0081]
[0082] (4) Generate the mandrel traction trajectory based on the mandrel shape, convergence zone state and weaving speed.
[0083] The spindle traction trajectory is described by the TCP's position, attitude, and movement speed. Specifically, its traction trajectory consists of a series of trajectory sampling points Q. i and the corresponding traction speed v at each point i express.
[0084] For trajectory point Q i ,have:
[0085]
[0086] Where, x g,i y g,i , z g,i Indicates TCP i Coordinates in the world coordinate system Indicates TCP i The posture, that is, successively around x g Axis rotation Around y g Axis rotation Around z g Axis rotation
[0087] When weaving reaches section T i To ensure that the actual weaving angle is equal to the target weaving angle, the mandrel pose should meet the following two requirements: 1. The cross-section normal vector n i 1. Aligned with the central axis of the braiding machine; 2. Center point P of the cross section i Located on the central axis of the braiding machine, and at a distance equal to the convergence zone length h from the guide ring. i ,like Figure 9 As shown. To ensure the cross-section normal vector n i Aligned with the central axis of the braiding machine, the mandrel can be rotated around axis n o,i Rotation Make vector n i With n b Overlap, where n b =[0,0,1], representing the direction of the centerline of the braiding machine. o,i and The calculation formula is as follows:
[0088]
[0089]
[0090] The rotation matrix R corresponding to this rotation transformation i The calculation is as follows:
[0091]
[0092] Where, n ox,i noy,i n oz,i Representing n respectively o,i In x g y g , z g The components on the axis, and when n b When n = [0,0,1], n can be calculated. oz,i =0.
[0093] To ensure the center point P of the cross section i Located on the central axis of the braiding machine, and at a distance equal to the convergence zone length h from the guide ring. i TCP i The coordinates should be:
[0094] x g,i =-x′ t,i (17)
[0095] y g,i =-y′ t,i (18)
[0096] z g,i =-z′ t,i -h i (19)
[0097] Where, x′ t,i y′ t,i , z′ t,i P is the center point of the cross section. i The rotated coordinates are:
[0098]
[0099] To describe the trajectory point Q i The rotation angle representing the attitude needs to be calculated. mandrel around axis n o,i Rotation The rotational transformation can also be achieved by sequentially rotating around x. g axis, y g axis, z g Axis rotation To achieve this rotation transformation, the rotation matrix R′ is required. i The calculation is as follows:
[0100]
[0101] The two rotational transformations have the same effect, therefore R i =R′ i It can be solved
[0102]
[0103]
[0104]
[0105] For traction speed v i Due to the influence of transient processes, its value is not always equal to the weaving speed v. b,i Instead, it is equal to the sum of the weaving speed and the rate of change of the convergence zone length, therefore:
[0106]
[0107] Among them, v b,i Δl represents the weaving speed of the i-th section. i Δh represents the distance between the i-th cross section and the (i+1)-th cross section. i Δt represents the change in the length of the convergence zone during the weaving process from the i-th section to the (i+1)-th section. i This represents the time elapsed from the i-th section to the (i+1)-th section during the weaving process.
[0108] The above calculations yield the traction trajectory sampling point Q. i and the corresponding traction speed v at each point i The calculation results are input into the robotic arm controller to achieve traction of the spindle.
[0109] Corresponding to the aforementioned embodiment of a method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, the present invention also provides an embodiment of a device for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes.
[0110] See Figure 10 The present invention provides a device for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, comprising one or more processors for implementing a method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes as described in the above embodiments.
[0111] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.
[0112] An embodiment of the device for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes according to the present invention can be applied to any device with data processing capabilities, such as a computer. The device embodiment can be implemented in software, hardware, or a combination of both. Taking software implementation as an example, as a logical device, it is formed by the processor of any data processing device loading the corresponding computer program instructions from non-volatile memory into memory for execution. From a hardware perspective, such as... Figure 10 The diagram shown is a hardware structure diagram of any device with data processing capabilities, which includes a device for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes according to the present invention. (Except for...) Figure 10 In addition to the processor, memory, network interface, and non-volatile memory shown, any data processing device in the embodiment may also include other hardware depending on the actual function of the data processing device, which will not be described in detail here.
[0113] The specific implementation process of the functions and roles of each unit in the above device can be found in the implementation process of the corresponding steps in the above method, and will not be repeated here.
[0114] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the present invention according to actual needs. Those skilled in the art can understand and implement this without creative effort.
[0115] This invention also provides a computer-readable storage medium storing a program that, when executed by a processor, implements a method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, as described in the above embodiments.
[0116] The computer-readable storage medium can be an internal storage unit of any data processing device described in any of the foregoing embodiments, such as a hard disk or memory. The computer-readable storage medium can also be any data processing device, such as a plug-in hard disk, smart media card (SMC), SD card, flash card, etc., equipped on the device. Furthermore, the computer-readable storage medium can include both internal storage units of any data processing device and external storage devices. The computer-readable storage medium is used to store the computer program and other programs and data required by the data processing device, and can also be used to temporarily store data that has been output or will be output.
[0117] The above embodiments are only used to illustrate the design concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made based on the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.
Claims
1. A method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, characterized in that, Includes the following steps: (1) Determine the three-dimensional model of the mandrel and extract the centerline, shape, and size parameters of the mandrel; (2) Based on the extracted mandrel parameter data and the target geometry of the fabric, calculate the convergence zone state at each stage of the weaving process; (3) Based on the convergence zone state and the target geometry of the fabric, calculate the weaving speed at each stage of the weaving process under the given weaving machine speed. (4) Generate the mandrel traction trajectory based on the mandrel shape, convergence zone state, and weaving speed; The traction trajectory consists of a series of trajectory sampling points Q i and the corresponding traction speed v at each point i express; At the trajectory sampling points, when the weaving proceeds to the mandrel section T i At this point, by rotating and translating the mandrel, the normal direction of the cross section is aligned with the direction of the braiding machine's central axis. Simultaneously, the center point of the cross section lies on the braiding machine's central axis, and its distance to the guide ring is equal to the length of the convergence zone. The TCP pose at this moment is calculated and used as the trajectory sampling point Q. i ; The traction speed v i The sum of the weaving speed and the rate of change of the convergence zone length is calculated using the following formula: Among them, v b,i This represents the weaving speed of the i-th section. This represents the distance between the i-th cross section and the (i+1)-th cross section. This represents the change in the length of the convergence zone during the weaving process from the i-th section to the (i+1)-th section. This represents the time elapsed from the i-th section to the (i+1)-th section during the weaving process.
2. The method according to claim 1, characterized in that, The extraction of the mandrel's centerline and shape and size parameters specifically involves: dividing the mandrel evenly into m segments to generate m+1 cross-sections, including the first end face and the last end face; the end furthest from the braiding machine is the mandrel's first end; the first cross-section is the first end face; For each section T i Calculate the coordinates of its center point P. i The sampling points of the mandrel centerline are obtained, and connecting all the sampling points gives the mandrel centerline. For each section T i Calculate its unit normal vector n i Circumference c i Equivalent radius r i Equivalent cone angle γ i This allows us to obtain the shape and size parameters of each position on the mandrel.
3. The method according to claim 1, characterized in that, The target geometry of the fabric is represented by the target weave angle, with a target weave angle α set at each mandrel cross section. i The convergence region state is determined by the convergence region length h. i Angle θ with the convergence region i The relationship between the target braiding angle, mandrel shape, convergence zone length, and convergence zone angle is described below: in, Indicates the radius of the guide ring.
4. The method according to claim 1, characterized in that, The rotational speed of the braiding machine is equal to the sum of the braiding angular velocity and the rate of change of the angle between the braiding and the convergence zones, where the braiding angular velocity ω... b,i The calculation formula is as follows: Where ω represents the knitting machine speed, θ i Let Δθ represent the angle between the convergence regions of the i-th cross section. i = θ i+1 - θ i , α represents the distance between the i-th cross section and the (i+1)-th cross section. i This represents the target weave angle of the i-th section.
5. The method according to claim 1, characterized in that, The weaving speed v b,i The calculation formula is as follows: Where, ω b,i α represents the weaving angular velocity of the i-th section. i This represents the target weave angle of the i-th section.
6. The method according to claim 1, characterized in that, The mandrel traction trajectory is described by the position, attitude, and traction speed of the center point TCP of the end tool of the robotic arm; the TCP coincides with the center point of the mandrel's first end face.
7. A device for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, characterized in that, It includes one or more processors for implementing the method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, as described in any one of claims 1-6.
8. A computer-readable storage medium having a program stored thereon, characterized in that, When executed by the processor, the program is used to implement the method for solving the traction trajectory of a ring-shaped braided mandrel considering transient processes, as described in any one of claims 1-6.