A virtual axis-based multi-axis winding machine operation configuration design method

Abstract

The application discloses a kind of based on virtual axis's multi-axis winding machine operation configuration design method, it is related to the field of automatic processing technology, including steps: according to the space position relationship of each movement axis of target winding machine kinematics modeling and extracting pose information at filament nozzle;With yarn guide roller at filament nozzle as axis to establish virtual rotary movement axis, and obtain yarn guide point at yarn guide roller radius distance based on virtual rotary movement axis;With yarn guide point yarn guide direction as axis to establish virtual translation movement axis, and obtain drop-off point according to the translation length of yarn bundle based on virtual translation movement axis;According to the pose information of filament nozzle, the deflection angle of yarn guide point and the translation length of drop-off point, establish the homogeneous matrix of drop-off point;Based on the kinematics inverse solution of drop-off point homogeneous matrix of target winding path, and obtain the operation configuration of target winding machine.The application effectively increases the redundancy degree of freedom of winding machine, and can better upgrade traditional winding machine.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automation processing technology, in particular to a multi-axis winding machine operation configuration design method based on virtual axis. BACKGROUND

[0002] Fiber winding technology is one of the key technologies and important means to improve the manufacturing efficiency and reduce the manufacturing cost of composite material components. Compared with other composite material forming technologies, fiber winding technology can design winding paths according to the structural characteristics and actual working conditions of the product, and fully play the characteristics of high strength and high modulus of fiber. At the same time, winding forming has the advantages of uniform fiber distribution and few defects, and is widely used in aerospace and civil industry, such as rocket engine shell, pressure vessel, sports equipment, etc.

[0003] In the process of fiber winding forming, the winding machine will continuously wind the yarn bundle on the rotating core mold under the control of constant tension according to the preset winding path. The common winding machine on the market usually has two to six degrees of freedom, or uses industrial robots for winding operation. The traditional winding machine trajectory planning method is based on envelope surface solving, such as constant hanging yarn length envelope and core mold contour envelope. However, for traditional winding machines, due to the low degree of freedom and poor flexibility, this trajectory method will cause the failure of inverse kinematics solution, and it is difficult to plan the winding path of complex core mold. Although industrial robots have many degrees of freedom, they are high in cost and difficult to control, and are not universal. Therefore, a reasonable, universal and efficient winding machine trajectory planning method is an important and urgent issue in winding forming process. SUMMARY

[0004] In order to enable the traditional multi-axis winding machine to also perform the winding task of complex core mold, the present application proposes a multi-axis winding machine operation configuration design method based on virtual axis, including the following steps:

[0005] S1: kinematic modeling according to the spatial position relationship of each motion axis of the target winding machine;

[0006] S2: obtaining the pose information of the target winding machine nozzle according to the kinematic modeling;

[0007] S3: establishing a virtual rotary motion axis with the yarn outlet roller at the nozzle as the axis, and obtaining the yarn outlet point at the radius distance of the yarn outlet roller based on the virtual rotary motion axis;

[0008] S4: establishing a virtual translational motion axis with the yarn outlet direction of the yarn outlet point as the axis, and obtaining the yarn dropping point according to the translational length of the yarn bundle based on the virtual translational motion axis;

[0009] S5: Establishing the homogeneous matrix of the doffing point according to the pose information of the nozzle, the deflection angle of the yarn shedding point and the translation length of the doffing point;

[0010] S6: Performing the kinematic inverse solution of the homogeneous matrix of the doffing point based on the target winding path of the mandrel and obtaining the running configuration of the target winding machine.

[0011] Further, the nozzle of the target winding machine performs spatial translation with the help of the translation motion axis and performs spatial rotation with the help of the rotation motion axis.

[0012] Further, in the S5 step, the homogeneous matrix of the doffing point is as follows:

[0013]

[0014] In the formula, H matrix is the homogeneous expression at the doffing point of the target winding machine, i is a constant, indicating the order of each doffing point in the target winding path, T is the tangent direction of the doffing point, N is the outer normal direction of the doffing point on the mandrel, B is the yarn band width direction, and P is the spatial position of the doffing point.

[0015] Further, in the S6 step, the running trajectory of the target winding machine is obtained through the following steps:

[0016] S61: Reading the current doffing point according to the target winding path and obtaining the running configuration of the target winding machine at the current doffing point according to the kinematic inverse solution of the homogeneous matrix of the current doffing point;

[0017] S62: Reading the next doffing point according to the target winding path and obtaining the running configuration of the target winding machine at the next doffing point according to the kinematic inverse solution of the homogeneous matrix of the next doffing point;

[0018] S63: Determining whether the running configuration design of all doffing points in the target winding path is completed, if yes, completing the running configuration design, and if no, returning to the S62 step.

[0019] Further, the S62 step specifically includes the following steps:

[0020] S621: Obtaining the rotation angle of the mandrel during the winding of the yarn from the current doffing point to the next doffing point according to the target winding path;

[0021] S622: Performing coupling solution between each motion axis of the target winding machine according to the rotation angle of the mandrel;

[0022] S623: Obtaining the running configuration at the next doffing point by performing kinematic inverse solution on the coupling solution result.

[0023] Further, the coupling solution is represented by the following formula:

[0024]

[0025] wherein, Δt is the difference between the next doffing point homogeneous matrix and the current doffing point homogeneous matrix, J r is the Jacobian matrix of the target winding machine, -J s is the mandrel rotation contribution part, Δq r is the posture change of the target winding machine and the virtual motion axis, Δθ s is the rotation angle of the mandrel during the winding of the yarn from the current doffing point to the next doffing point.

[0026] Further, the S62 step further comprises the following steps after the S62 step:

[0027] S624: judging whether the running configuration at the next doffing point meets the preset running requirement, if yes, entering the S63 step, if no, adjusting the running configuration and returning to the S622 step.

[0028] Further, in the S61 step, if the current doffing point is the initial doffing point, the initial configuration is selected according to the preset running requirement.

[0029] Compared with the prior art, the present application has at least the following beneficial effects:

[0030] (1) The multi-axis winding machine running configuration design method based on virtual axis has the advantages that the two virtual axes of the yarn deflection and the yarn length are added, so that the running configuration of the winding machine is designed, and due to the increase of the axes, the redundant degrees of freedom of the winding machine are effectively increased, so that the problems caused by the limited degrees of freedom, such as joint overstroke, singularity and interference, can be avoided during the winding of the complex mandrel.

[0031] (2) Since the running trajectory is designed by adding the virtual axes, no additional constraints need to be added to the winding path, and the rotation of the main shaft is also coupled into the kinematics solving, so that the method has universality and can better upgrade and improve the traditional winding machine. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a step diagram of the multi-axis winding machine running configuration design method based on virtual axis;

[0033] Figure 2 is an axial schematic diagram of each motion axis in the traditional six-axis winding machine;

[0034] Figure 3 is a schematic diagram of the virtual motion axis at the yarn nozzle.

[0035] Explanation of the accompanying numbers: 1-vertical translation axis, 2-lateral translation axis, 3-vertical translation axis, 4-third rotation axis, 5-first rotation axis, 6-second rotation axis, 7-virtual rotation axis, 8-yarn outlet point, 9-yarn drop point. DETAILED DESCRIPTION

[0036] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0037] Example 1

[0038] Compared with industrial robots, traditional winding machines are certainly inferior in terms of operational freedom, which makes it difficult for them to perform highly complex core winding tasks. However, due to their low cost and simple control, they still occupy a large part of the market share. Figure 2 As shown, a traditional six-axis winding machine includes three translational motion axes (a lateral translational motion axis 2 in the X-axis direction, a vertical translational motion axis 1 in the Y-axis direction, and a vertical translational motion axis 3 in the Z-axis direction) and three rotational motion axes (a first rotational axis 5 rotating about the X-axis, a second rotational axis 6 (a fixed axis) rotating about the Y-axis, and a third rotational axis 4 rotating about the Z-axis). Taking the six-axis winding machine as an example, it has only one kinematic chain, namely, the kinematic chain of Y translation axis → X translation axis → Z translation axis → Z rotation axis → X rotation axis → yarn dropping point. As for the rotation of the core mold main axis, the existing technology changes the rotation speed of the core mold so that all the yarn drops fall on a certain plane. That is to say, they first give a core mold rotation angle, and then seek the inverse solution of the kinematic chain of the winding machine. It can be seen that its degree of freedom is very limited.

[0039] In order to help enterprises upgrade the performance of winding machines without replacing equipment, such as Figure 1 As shown, the present invention proposes a method for designing the operating configuration of a multi-axis winding machine based on a virtual axis, wherein the nozzle of the multi-axis winding machine can be spatially translated with the help of a translational motion axis and can be spatially rotated with the help of a rotational motion axis, specifically comprising the following steps:

[0040] S1: Kinematic modeling is performed based on the spatial position relationship of each motion axis of the target winding machine;

[0041] S2: Obtain the position information of the target winding machine nozzle based on kinematic modeling;

[0042] S3: establishing a virtual rotation axis with the yarn outlet roller at the yarn nozzle as the axis, and obtaining the yarn outlet point at the radial distance of the yarn outlet roller based on the virtual rotation axis;

[0043] S4: Establish a virtual translation motion axis with the yarn shedding point as the axis, and obtain the shedding point according to the translation length of the yarn bundle on the basis of the virtual translation motion axis;

[0044] S5: Establish the homogeneous matrix of the shedding point according to the pose information of the nozzle, the deflection angle of the shedding point and the translation length of the shedding point;

[0045] S6: Perform kinematic inverse solution of the shedding point homogeneous matrix based on the target winding path of the mandrel, and obtain the running configuration of the target winding machine.

[0046] The running trajectory of the target winding machine is specifically obtained by the following steps:

[0047] S61: Read the current shedding point according to the target winding path, and obtain the running configuration of the target winding machine at the current shedding point according to the kinematic inverse solution of the current shedding point homogeneous matrix;

[0048] S621: Obtain the rotation angle of the mandrel during the winding of the yarn from the current shedding point to the next shedding point according to the target winding path;

[0049] S622: Perform coupling solution between the target winding machine and each motion axis according to the rotation angle of the mandrel;

[0050] S623: Obtain the running configuration at the next shedding point by performing kinematic inverse solution on the coupling solution result;

[0051] S624: Determine whether the running configuration at the next shedding point meets the preset running requirement, if yes, proceed to S63, if no, adjust the running configuration and return to S622;

[0052] S63: Determine whether the running configuration design of all shedding points in the target winding path is completed, if yes, complete the running configuration design, if no, return to S62.

[0053] Here, the joint variables of the axes of the multi-axis device are collectively referred to as "configuration". "Pose" is used to describe a coordinate system or rigid body in three-dimensional space, which is divided into "position" and "attitude".

[0054] In this embodiment, we take the six-axis winding machine shown in Figure 2 as the target winding machine to explain the technical content of the present application. First, by determining the relative position relationship between the motion axes, the corresponding kinematic modeling is performed, and the pose information at the nozzle of the target winding machine is obtained through modeling. Of course, other ways such as D-H parameters can also be used for modeling to obtain the pose information at the nozzle of the target winding machine. According to the kinematic model after modeling, the following pose homogeneous matrix expression of the nozzle can be obtained:

[0055]

[0056] Where 0 represents the world coordinate system, 1 represents the coordinate system of the vertical translation axis, 2 represents the coordinate system of the horizontal translation axis, 3 represents the coordinate system of the vertical translation axis, 4 represents the coordinate system of the third rotation axis, and 5 represents the coordinate system of the first rotation axis at the nozzle. (i and j are constants) is the relative pose of coordinate system j relative to coordinate system i, expressed in the form of a homogeneous matrix; is the displacement of the origin of coordinate system j relative to the origin of coordinate system i; d x ,d y ,d z ,θ a ,θ c Refers to the translational freedom along the x-axis, the translational freedom along the y-axis, the translational freedom along the z-axis, the rotational freedom along the x-axis, and the rotational freedom along the z-axis respectively; I is the unit matrix. Represented as a translation d along the y-axis y , It represents the rotation θ along the z axis. c We will use this as an example to explain, and will not elaborate on the meaning of other formula contents.

[0057] After obtaining the posture information at the wire mouth, it is considered that the traditional winding machine is limited by its own motion axis. For example, fewer physical motion axes are set. In this way, since there are fewer restrictions to consider, the operating configuration of the winding machine can be designed more simply. However, when faced with more complex core molds, it is difficult to perform complex winding tasks due to insufficient redundant degrees of freedom. If too many physical motion axes are set, it is necessary to consider whether each motion axis has problems such as overtravel, singularity and interference, which leads to too many restrictions. When faced with complex core mold winding tasks, it takes twice as long to design the operating configuration of the winding machine. At the same time, deviations are very likely to occur during actual operation. Therefore, the present invention proposes to increase the redundant degrees of freedom of the winding machine by adding virtual axes without worrying about the problem of increased restrictions.

[0058] Specifically, the present invention is with a wire mouth (such as Figure 2 The yarn outlet roller is used as the axis to establish a virtual rotation axis (such as the device at the position of 5 in the middle) Figure 3 The axis 7 in the figure is used, and the yarn outlet point is obtained at the yarn outlet roller radius distance based on the virtual rotation axis (such as Figure 3 The yarn-out point is the point 8 in the figure. The yarn-out direction is used as the axis to establish a virtual translation axis, and the yarn-dropping point is obtained based on the translation length of the yarn bundle on the basis of the virtual translation axis ( Figure 3point 9 in the figure, i.e. the point where the yarn falls on the core mold. That is, the kinematic chain is expanded from the original to the first kinematic chain in the application: Y translation axis → X translation axis → Z translation axis → Z rotation axis → X rotation axis → virtual rotation motion axis → virtual translation motion axis → doffing point.

[0059] After the expansion of the kinematic chain, the pose information of the nozzle in different states, and the deflection angle of the doffing point (such as Figure 3 θ in the figure) and the translation length of the doffing point (i.e. the length between the doffing point and the doffing point) will affect the pose of the doffing point, so the homogeneous matrix of the doffing point at this time is:

[0060]

[0061] In the formula, H matrix is the homogeneous expression of the doffing point of the target winding machine, i is a constant, indicating the order of each doffing point in the target winding path, T is the tangent direction of the doffing point, N is the outer normal direction of the doffing point on the core mold, B is the yarn width direction, and P is the spatial position of the doffing point.

[0062] According to the homogeneous matrix of the doffing point, we can perform kinematic inverse solution according to the planned target winding path to obtain the running configuration of the target winding machine at each time when winding according to the target winding path. Specifically, first, read the initial doffing point in the target winding path, construct the homogeneous matrix of the doffing point, and solve the initial configuration of the target winding machine through kinematic inverse solution. It should be noted that due to the existence of two virtual motion axes, there are many solutions for the initial configuration. Here, we can select the initial configuration according to the preset running requirements.

[0063] Then read the next doffing point from the target winding path. However, since the core mold main shaft is in a rotating state during winding, we introduce a second kinematic chain, i.e. the main shaft kinematic chain (which rotates along the Y axis and is independent of the first kinematic chain). In order to eliminate the position deviation of the doffing point caused by the rotation of the main shaft, we need to perform a rotation operation along the main shaft of the core mold on the initial path point to obtain the actual next doffing point of the target winding machine. Considering that the rotation of the target winding machine and the core mold is actually relative motion, the rotation angle of the core mold can be coupled with the motion axes of the target winding machine through the following formula, i.e. all degrees of freedom are coupled and solved, instead of solving other degrees of freedom by giving the rotation angle of the core mold. The result of the kinematic inverse solution coupling can obtain the running configuration of the target winding machine corresponding to the next doffing point.

[0064]

[0065] In the formula, At is the difference between the next doffing point homogeneous matrix and the current doffing point homogeneous matrix, J r J is the Jacobian matrix of the target winding machine s is the core mold rotation contribution part, and r is the configuration change of each motion axis and the virtual motion axis of the target winding machine s is the rotation angle of the core mold during the winding of the yarn from the current doffing point to the next doffing point.

[0066] Of course, after obtaining the configuration of the target winding machine corresponding to a doffing point, it is also necessary to judge whether the configuration meets the preset operation requirements, such as whether the rotation or extension limit of the joint of a place axis is exceeded, whether interference with the core mold or other components occurs, etc. If it is unreasonable, the configuration of the target winding machine needs to be adjusted, and the configuration adjustment of a place axis joint leads to the corresponding adjustment of other axis joints. Therefore, the inverse kinematics needs to be solved again by the above formula to obtain the next suitable configuration.

[0067] In summary, the multi-axis winding machine operation configuration design method based on virtual axes provided by the present application designs the operation configuration of the winding machine by adding two virtual axes of the yarn deflection and the yarn length. Due to the increase of the axes, the redundant degrees of freedom of the winding machine are effectively increased, which can avoid the problems such as joint overstroke, singularity and interference caused by limited degrees of freedom when winding a complex core mold.

[0068] Since the operation trajectory is designed by increasing the virtual axes, no additional constraints need to be added to the winding path, and the rotation of the main shaft is also coupled into the kinematics solution, so it has universality and can better upgrade the traditional winding machine.

[0069] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, motion condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0070] In addition, the descriptions such as "first", "second", "one" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0071] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, can be internal communication of two elements or interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0072] In addition, the technical solutions among various embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the protection scope required by the present application.

Claims

1. A method for designing a virtual-axis-based operating configuration of a multi-axis winding machine, characterized in that, The method comprises the steps of: S1: kinematic modeling according to the spatial position relationship of each movement axis of the target winding machine; S2: obtaining the pose information of the target winding machine nozzle according to the kinematic modeling; S3: establishing a virtual rotational movement axis with the nozzle roller as the axis, and obtaining the yarn shedding point at the radius distance of the nozzle roller based on the virtual rotational movement axis; S4: establishing a virtual translational movement axis with the yarn shedding direction as the axis, and obtaining the yarn shedding point according to the translational length of the yarn bundle based on the virtual translational movement axis; S5: establishing the homogeneous matrix of the yarn shedding point according to the pose information of the nozzle, the deflection angle of the yarn shedding point, and the translational length of the yarn shedding point; S6: kinematic inverse solution of the yarn shedding point homogeneous matrix based on the target winding path of the mandrel, and obtaining the running configuration of the target winding machine.

2. A method of designing a virtual-axes-based operating configuration of a multi-axes winding machine according to claim 1, characterized in that, The nozzle of the target winding machine is translated in space with the help of the translational movement axis, and is rotated in space with the help of the rotational movement axis.

3. A method of designing a virtual-axes-based operating configuration of a multi-axes winding machine according to claim 1, characterized in that, In the S5 step, the homogeneous matrix of the yarn shedding point is as follows: In the formula, H matrix is the homogeneous expression of the yarn shedding point of the target winding machine, i is a constant, indicating the order of each yarn shedding point in the target winding path, T is the tangent direction of the yarn shedding point, N is the outer normal direction of the yarn shedding point on the mandrel, B is the yarn width direction, and P is the spatial position of the yarn shedding point.

4. A virtual axis based multi-axis winding machine operation configuration design method as claimed in claim 1, wherein, In the S6 step, the running trajectory of the target winding machine is obtained through the following steps: S61: reading the current yarn shedding point according to the target winding path, and obtaining the running configuration of the target winding machine at the current yarn shedding point according to the kinematic inverse solution of the current yarn shedding point homogeneous matrix; S62: reading the next yarn shedding point according to the target winding path, and obtaining the running configuration of the target winding machine at the next yarn shedding point according to the kinematic inverse solution of the next yarn shedding point homogeneous matrix; S63: determining whether the running configuration design of all yarn shedding points in the target winding path is completed, if yes, completing the running configuration design, and if no, returning to the S62 step.

5. A virtual axis based multi-axis winding machine operation configuration design method as claimed in claim 4, wherein, The S62 step specifically comprises the steps of: S621: obtaining the rotation angle of the mandrel during the winding of the yarn from the current yarn shedding point to the next yarn shedding point according to the target winding path; S622: coupling solving between the rotation angle of the mandrel and each movement axis of the target winding machine; S623: obtaining the running configuration at the next yarn shedding point by kinematic inverse solution of the coupling solving result.

6. A virtual axis based multi-axis winding machine operation configuration design method as claimed in claim 5, wherein, The coupling solving is represented by the following formula: where Δt is the difference between the next doffing point homogeneous matrix and the current doffing point homogeneous matrix, J r is the Jacobian matrix of the target winding machine, -J s is the mandrel rotation contribution, Δq r is the configuration change of the target winding machine's motion axes and virtual motion axes, Δθ s is the mandrel rotation angle during the process of winding the yarn from the current doffing point to the next doffing point.

7. A virtual axis based multi-axis winding machine operation configuration design method as claimed in claim 5, wherein, After the S62 step, the following steps are further included: S624: determining whether the running configuration at the next yarn shedding point meets the preset running requirements, if yes, entering the S63 step, and if no, adjusting the running configuration and returning to the S622 step.

8. A virtual axis based multi-axis winding machine operation configuration design method as claimed in claim 4, wherein, In the S61 step, if the current yarn shedding point is the initial yarn shedding point, the initial configuration is selected according to the preset running requirements.

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