Constant-tension fiber winding device and control method thereof

Abstract

The invention relates to a constant-tension fiber winding device and a control method thereof. The constant-tension fiber winding device comprises a first motor, a second motor, a first mandrel, a second mandrel, a first fixed pulley, a second fixed pulley, a movable pulley with a force sensor, a constant force device, a sensor, a feedback controller and a base. The first mandrel and the second mandrel are fixed to the base, the first motor controls the rotating speed of the first mandrel, and the second motor controls the rotating speed of the second mandrel. The constant force device is arranged between the first mandrel and the second mandrel. The movable pulley with the force sensor is arranged on the upper portion of the constant-force device. The first fixed pulley and the second fixed pulley are fixedly arranged on the two sides of the constant-force device. And the fiber is pulled out from the mandrel I, sequentially passes through the fixed pulley I, the movable pulley with the force sensor and the fixed pulley II, and then is wound on the mandrel II. The sensor measures the constant force device in real time, and when the measured value of the constant force device exceeds a preset range, the feedback controller controls the second motor to change the rotating speed of the second mandrel, so that the measured value of the constant force device is within the preset range, and the fiber tension is kept constant. The constant force device adopted by the invention is simple in mechanism and easy to operate, and the sensitivity requirement of the feedback controller can be greatly reduced, so that the control difficulty and cost can be greatly reduced.

Description

Technical Field

[0001] The invention relates to a fiber winding device, in particular to a constant tension fiber winding device and a control method thereof. Background Art

[0002] The fiber winding process is widely used in high-tech industries such as aerospace and new energy. In the fiber winding process, the fiber winding tension is a crucial process parameter, which is related to the effect of the fiber during the dipping, the fiber ratio, and the porosity, and directly determines the strength of the wound product.

[0003] Traditional tension control strategies, such as rigid actuators or series elastic actuators, require expensive electronic components or complex tension feedback control, which are not only costly but also face great challenges in dealing with complex winding interfaces, sharp turns in trajectories, and rapidly changing fiber internal forces.

[0004] Chinese invention patent 201410016757.X discloses a constant tension controlled fabric winding device, which changes the unwinding speed of the fabric through a tension measurement-feedback-control loop to achieve the purpose of controlling the winding tension, thereby realizing constant tension controlled winding. This control method requires real-time measurement of the internal force of the fabric and rapid adjustment of the internal force disturbance. It has high requirements for the measurement-feedback-control system and requires expensive hardware equipment and complex and advanced control algorithms to achieve.

[0005] Chinese invention patent 201610621804.2 discloses a modular control system for carbon fiber winding tension, which realizes the unwinding function through the unwinding module, and sequentially arranges a single-bundle fiber tension detection module, an active speed regulation module, a buffer module, a bundled fiber tension detection module and a speed measurement module between the unwinding module and the core mold, and receives the tension signal detected by the single-bundle and bundled fiber tension detection module and the speed signal detected by the speed measurement module through the control console, and after processing, controls the active speed regulation module and the unwinding module to keep the single-bundle and bundled fiber tension within the preset error range. The buffer module is used to effectively reduce the fiber tension fluctuation during the fiber winding process. This control system requires complex and expensive control modules to ensure that the fiber internal force remains within the preset error range.

[0006] During the fiber winding process, due to the uniformity of fiber thickness, the uniformity of fiber winding on core shaft one, the change in the angle of fiber pulling out from core shaft one, the change in the angle of fiber entering core shaft two, the friction between components, the inertia of the core shaft, the damping of the system, etc., the speed of fiber pulling out from core shaft one and the speed of fiber entering core shaft two are inconsistent, resulting in the fiber between core shaft one and core shaft two being loose and tight, and the internal force of the fiber changing rapidly. Traditional fiber winding devices usually use force control methods. In order to ensure the quality of winding, the control of fiber tension is very strict, and only a small deviation is allowed. This requires the use of precise and expensive force sensors to monitor the fiber tension in real time, and to cooperate with complex control algorithms and expensive hardware controllers to quickly adjust the rotation speed of core shaft two in real time to ensure that the fiber tension is constant. Summary of the invention

[0007] In view of the deficiencies of the prior art, the present invention proposes a constant tension fiber winding device and a control method thereof, the purpose of which is to achieve constant tension using a simple mechanism, cheap equipment and a simple algorithm, thereby reducing control difficulty and cost.

[0008] The technical solution of the present invention is achieved in this way:

[0009] A constant tension fiber winding device and a control method thereof, comprising: a first motor and a second motor, a first core shaft and a second core shaft, a first fixed pulley and a second fixed pulley, a movable pulley with a force sensor, a constant force device, a sensor, a feedback controller, and a base.

[0010] Mandrel 1 and mandrel 2 are fixed on the base, motor 1 controls the rotation speed of mandrel 1, and motor 2 controls the rotation speed of mandrel 2. The constant force device is arranged between mandrel 1 and mandrel 2. The movable pulley with force sensor is arranged on the upper part of the constant force device, and fixed pulley 1 and fixed pulley 2 are fixedly arranged on both sides of the constant force device. The fiber is pulled out from mandrel 1, passes through fixed pulley 1, movable pulley with force sensor and fixed pulley 2 in sequence, and then is wound on mandrel 2. The sensor measures the constant force device in real time. When the measurement value of the constant force device exceeds the preset range, the feedback controller controls motor 2 to change the rotation speed of mandrel 2, so that the measurement value of the constant force device is within the preset range, thereby keeping the fiber tension constant.

[0011] Among them, the constant force device is optimized in design so that when the constant force device is subjected to pressure, the constant force device outputs constant force within a certain displacement range.

[0012] Furthermore, the constant force device includes a first surface, a second surface, a guide tube, and a constant force unit between the first surface and the second surface.

[0013] Furthermore, the second surface is fixed on the base, the guide tube is fixed in the middle of the second surface, the first surface is slidably connected to the guide tube, so that the first surface can move up and down along the guide tube, and the constant force unit between the first and second surfaces is deformed by the compression of the first surface.

[0014] Furthermore, the first surface is parallel to the second surface.

[0015] Furthermore, the surface of the guide tube is smooth, and a ball bearing is used between the first surface and the guide tube to reduce friction.

[0016] Furthermore, the constant force unit includes one or more inclined slender columns or inclined thin sheets.

[0017] Furthermore, the constant force unit is preferably an inclined thin sheet.

[0018] Furthermore, the slenderness ratio of the constant force unit is >10.

[0019] Furthermore, the axis of the constant force unit is a straight line.

[0020] Furthermore, the axis of the constant force unit is a curve.

[0021] Furthermore, the constant force unit is provided with one or more bending portions near the first surface / the second surface.

[0022] Furthermore, the angle between the intersection point of the constant force unit and the first surface, and the intersection point of the constant force unit and the second surface, and the line connecting the two intersection points and the first surface or the second surface is 50-130°.

[0023] Furthermore, the constant force units are symmetrically arranged in pairs.

[0024] Furthermore, the sensor is a displacement sensor.

[0025] Furthermore, the sensor is a force sensor.

[0026] Furthermore, the displacement sensor is a laser displacement sensor.

[0027] Furthermore, the feedback controller adopts a PID controller (proportional-integral-differential controller).

[0028] Furthermore, the feedback controller adopts a fuzzy controller.

[0029] The working principle and technical effect of the present invention are that, during the fiber winding process, when the speed at which the fiber is pulled out of mandrel one is inconsistent with the speed at which the fiber enters mandrel two, this will trigger the upper surface of the constant force device to move up and down, allowing the fiber length between mandrel one and mandrel two to change, ensuring that the fiber always remains in a tensioned state and the internal force always remains constant. Through optimized design, the displacement range of the constant force device is limited to a larger range. As long as the displacement of the constant force device is within this displacement range, the constant force device outputs a constant force, and the tension of the fiber is constant. Therefore, the adjustment frequency of the rotation speed of mandrel two can be greatly reduced, and the sensitivity requirements of the controller can be greatly reduced, so that a simpler and cheaper controller can be used, greatly reducing the control difficulty and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] The same parts are denoted by the same reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the drawings, and the words "bottom" and "top", "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0032] Figure 1 It is a structural schematic diagram of Example 1;

[0033] Figure 2 This is a structural diagram of the constant force device in Example 1;

[0034] Figure 3 This is a simplified structural diagram of the constant force device in Example 1;

[0035] Figure 4 This is a compression deformation diagram of the constant force device in Example 1;

[0036] Figure 5 This is a force-displacement curve diagram of the constant force device in Example 1;

[0037] Figure 6 This is a graph showing the change of the fiber tension force over time in Example 1;

[0038] Figure 7 is a graph showing the change of the fiber tension force over time in Example 2 of the present invention;

[0039] Figure 8 This is a graph showing the change in displacement of the constant force device over time in Example 2 of the present invention;

[0040] Fig. 9 is a graph showing the change of the fiber tension force over time in Example 3 of the present invention;

[0041] Fig.10 is a graph showing the change of the fiber tension force over time in Example 4 of the present invention;

[0042] Fig.11 This is a graph showing the change in displacement of the constant force device over time in Example 4 of the present invention;

[0043] Fig.12 This is a simplified structural diagram of the constant force device of Example 7;

[0044] Fig.13 This is a schematic structural diagram of the constant force device of Example 8;

[0045] Fig.14 This is a schematic diagram of the shape design of the constant force unit of Example 9;

[0046] In the above drawings, the figure numbers represent:

[0047] Mandrel 1;

[0048] 2, mandrel two;

[0049] 3, Motor 1;

[0050] 4, Motor 2;

[0051] 5. Constant force device;

[0052] 5-1, first surface;

[0053] 5-2, second surface;

[0054] 5-3, constant force unit;

[0055] 5-4, guide shaft;

[0056] 5-5, bending part;

[0057] 6. Fixed pulley one;

[0058] 7, fixed pulley 2;

[0059] 8. Movable pulley with force sensor;

[0060] 9. Laser displacement sensor;

[0061] 10. Controller;

[0062] 11. Base

[0063] 12, fiber; DETAILED DESCRIPTION

[0064] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the drawings of the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] Example 1

[0066] In a specific embodiment 1, Figure 1 As shown, a constant tension fiber winding device and a control method thereof include: 1 circular core shaft 1 and 2 circular core shaft 2, 3 motor 1 and 4 motor 2, 5 constant force device, 6 fixed pulley 1 and 7 fixed pulley 2, 8 movable pulley with force sensor, 9 laser displacement sensor and 10 PID feedback controller (proportional-integral-differential controller), 11 base and 12 fiber.

[0067] 1 circular mandrel 1 and 2 circular mandrel 2 are fixed on 11 base, 3 motor 1 controls the rotation speed of 1 circular mandrel 1, 4 motor 2 controls the rotation speed of 2 circular mandrel 2. 5 constant force device is fixedly arranged between 1 circular mandrel 1 and 2 circular mandrel 2. 8 movable pulley with force sensor is arranged on the upper part of 5 constant force device, 6 fixed pulley 1 and 7 fixed pulley 2 are fixedly arranged on both sides of 5 constant force device. 12 fiber is pulled out from 1 circular mandrel 1, passes through 6 fixed pulley 1, 8 movable pulley with force sensor, 7 fixed pulley 2 in sequence, and is wound on 2 circular mandrel 2, 9 laser displacement sensor measures the displacement of 5 constant force device in real time, when the displacement value of 5 constant force device exceeds the preset displacement range, 10 PID feedback controller controls 4 motor 2 to change the rotation speed of 2 circular mandrel 2, so that the displacement value of 5 constant force device is within the preset range.

[0068] Among them, the structure diagram of the 5 constant force device is as follows Figure 2 The structural diagram of the constant force device is as follows: Figure 3 , including: 5-1 a first surface, 5-2 a second surface, 5-3 a constant force unit, and 5-4 a guide tube.

[0069] Among them, the first surface 5-1 is parallel to the second surface 5-2.

[0070] Among them, the second surface 5-2 is fixedly set on the base 11, the guide tube 5-4 is fixedly set in the middle position of the second surface 5-2, and the first surface 5-1 is slidably connected with the guide tube 5-4, so that the first surface 5-1 can move up and down along the guide tube 5-4.

[0071] The 5-3 constant force unit is composed of 4 identical tilted thin plastic sheets. The axis of each plastic sheet is a straight line. The angle between the tilted thin plastic sheet and the upper surface is 60 degrees.

[0072] During the fiber winding process, the tensioned 12 fibers exert downward pressure on the 8 movable pulleys, compressing the 5 constant force devices, causing the upper surface 5-1 of the 5 constant force devices to move downward, driving the 5-3 constant force unit to undergo compression deformation. The deformation diagram of the 5 constant force devices is shown in FIG. Figure 4 .

[0073] 5. The pressure-displacement curve of the constant force device is as follows Figure 5 In this embodiment, the displacement of the constant force device is in the range of 3-25 mm, and the pressure of the constant force device is kept substantially constant, so that the tension of the fiber is kept substantially constant.

[0074] During the fiber winding process, due to the uniformity of fiber thickness, the uniformity of fiber winding on core shaft one, the change in the angle of fiber pulling out from core shaft one, the change in the angle of fiber entering core shaft two, friction between components, inertia of the core shaft, damping of the system and other reasons, the speed of fiber pulling out from core shaft one and the speed of fiber entering core shaft two are inconsistent, resulting in the fiber between core shaft one and core shaft two being loose and tight, and the internal force of the fiber changing rapidly. This requires the use of precise and expensive force sensors to monitor the tension of the fiber in real time, and to cooperate with complex control algorithms and expensive hardware controllers to quickly adjust the rotation speed of core shaft two in real time to control the tension of the fiber.

[0075] The working principle of the constant force device in this embodiment is that during the fiber winding process, due to the various reasons mentioned above, the speed at which the fiber is pulled out of mandrel one and the speed at which it enters mandrel two are inconsistent, which will trigger the upper surface of the constant force device to move up and down, allowing the fiber length between mandrel one and mandrel two to change, so as to ensure that the fiber always remains in a tensioned state and the internal force always remains constant. Through optimized design, this embodiment designs the constant force displacement range of the constant force device to be 3-25mm. As long as the displacement of the upper surface of the constant force device is within this displacement range, the tension of the fiber is constant.

[0076] In this embodiment, the effect of the constant force device on the fiber tension disturbance during the fiber winding process is as follows: Figure 6 . Figure 6 In the present invention, a conventional fiber winding device (without a constant force device) and a fiber winding device using a constant force device are compared.

[0077] It can be seen that with the traditional fiber winding device (without constant force device), the fiber tension curve shows a large number of frequent burrs, indicating that the tension has undergone rapid and drastic changes. In contrast, with the fiber winding device equipped with a constant force device, the fiber tension vibration peak is greatly reduced, the curve is smoother, and the tension makes a slight disturbance near the target value. This shows that after the constant force device is used, the change of tension is more moderate and the tension is better kept constant.

[0078] Example 2

[0079] In a preferred embodiment 2, the control method of embodiment 1 is changed to fuzzy control, that is, the feedback controller adopts a 10 fuzzy feedback controller, and other settings remain the same as embodiment 1.

[0080] The effect of the constant force device on the fiber tension disturbance during fiber winding is as follows: Figure 7 . Figure 7 In the embodiment, the PID control (Example 1) and the fuzzy control (Example 2) are compared. It can be seen that when the constant force device is used in the fiber winding device, the disturbance of the fiber tension force is in a very small range regardless of whether the PID control or the fuzzy control is used.

[0081] In both PID control (Example 1) and Fuzzy control (Example 2), the displacement disturbance of the constant force device is as follows: Figure 8 It can be seen that no matter whether PID control or fuzzy control is used, the displacement disturbance of the constant force device is basically in a very small range.

[0082] We know that PID control is to make the measured value close to the target value. The controller's adjustment frequency is as high as the measurement frequency to ensure that each measured value is close to the target value. Therefore, the PID control method has very high requirements on the sensitivity of the controller. Fuzzy control allows the measured value to fluctuate within a range near the target value. As long as the measured value is within this range, there is no need to start the controller for adjustment. Therefore, the sensitivity requirements of the controller can be greatly reduced.

[0083] In Example 2, we can see that after the constant force device is used, the constant force device allows the length of the fiber between mandrel 1 and mandrel 2 to change, that is, it allows the speed of mandrel 2 to differ from the speed of mandrel 1. As long as the speed difference between mandrel 2 and mandrel 1 is not enough to cause the displacement of the constant force device to exceed the allowable range, the fiber tension is constant, and there is no need to adjust the speed of mandrel 2. The setting of the constant force device greatly reduces the speed adjustment frequency of mandrel 2. The constant force device and fuzzy control are compatible. When the two are used together, the adjustment frequency of the controller can be greatly reduced when the system outputs constant force, thereby greatly reducing the sensitivity requirements of the controller.

[0084] Furthermore, when the constant force device is used in conjunction with fuzzy control and a high-sensitivity controller is adopted, the rotation speed of the mandrel can be greatly increased while ensuring a constant fiber tension force, thereby improving production efficiency.

[0085] Example 3

[0086] In Example 3, the circular mandrel 1 in Example 1 is changed to a football field shaped mandrel 1, and other configurations remain the same as in Example 1. In Example 3, the shapes of mandrel 1 and mandrel 2 are different, and during the fiber winding process, the fiber tension may change more dramatically.

[0087] The effect of the constant force device on the fiber tension disturbance during fiber winding is as follows: Fig. 9 . Fig. 9 In the present invention, a conventional fiber winding device (without a constant force device) and a fiber winding device using a constant force device are compared.

[0088] It can be seen that with the traditional fiber winding device (without constant force device), the fiber tension curve shows a large number of frequent burrs, indicating that the tension has undergone rapid and drastic changes. In contrast, with the fiber winding device equipped with a constant force device, the fiber tension vibration peak is greatly reduced, the curve is smoother, and the tension makes a slight disturbance near the target value. This shows that after the constant force device is used, the change of tension is more moderate and the tension is better kept constant.

[0089] Example 3 shows that, when the shapes of the mandrel 1 and the mandrel 2 are different, compared with the traditional fiber winding device (without the constant force device), the fiber tension disturbance curve is smoother after the constant force device is used, and the constant force control effect is better.

[0090] Example 4

[0091] In Example 4, the control method of Example 3 is changed to Fuzzy control, that is, the feedback controller adopts 10 Fuzzy feedback controller, and other settings remain the same as Example 3.

[0092] The effect of the constant force device on the fiber tension disturbance during fiber winding is as follows: Fig.10 . Fig.10 In the embodiment, the PID control (Example 3) and the fuzzy control (Example 4) are compared. It can be seen that when the constant force device is used in the fiber winding device, the disturbance of the fiber tension force is in a very small range regardless of whether the PID control or the fuzzy control is used.

[0093] In both PID control (Example 1) and Fuzzy control (Example 2), the displacement disturbance of the constant force device is as follows: Fig.11 It can be seen that no matter whether PID control or fuzzy control is adopted, the displacement disturbance of the constant force device is basically within the allowable range.

[0094] We know that PID control is to make the measured value close to the target value. The controller's adjustment frequency is as high as the measurement frequency to ensure that each measured value is close to the target value. Therefore, the PID control method has very high requirements on the sensitivity of the controller. Fuzzy control allows the measured value to fluctuate within a range near the target value. As long as the measured value is within this range, there is no need to start the controller for adjustment. Therefore, the sensitivity requirements of the controller can be greatly reduced.

[0095] In Example 4, we can see that after the constant force device is used, the constant force device allows the length of the fiber between mandrel 1 and mandrel 2 to change, that is, it allows the speed of mandrel 2 to differ from the speed of mandrel 1. As long as the speed difference between mandrel 2 and mandrel 1 is not enough to make the displacement of the constant force device exceed the allowable range, the fiber tension is constant, and there is no need to adjust the speed of mandrel 2. The setting of the constant force device greatly reduces the speed adjustment frequency of mandrel 2. The constant force device and fuzzy control are compatible. When the two are used together, the adjustment frequency of the controller can be greatly reduced when the system outputs constant force, thereby greatly reducing the sensitivity requirements of the controller.

[0096] Furthermore, when the constant force device is used in conjunction with fuzzy control and a high-sensitivity controller is adopted, the rotation speed of the mandrel can be greatly increased while ensuring a constant fiber tension force, thereby improving production efficiency.

[0097] Example 5

[0098] The difference between Example 5 and Example 1 is that the movable pulley with the force sensor is replaced with a general movable pulley.

[0099] In the case of setting a constant force device, as long as the displacement of the constant force device is within the allowable displacement range, the fiber tension is within the allowable error range. Therefore, it is only necessary to measure the displacement of the constant force device and adjust the rotation speed of the mandrel 2 according to the displacement measurement value so that the displacement of the constant force device is within the allowable displacement range. A force sensor is no longer needed to measure / calculate the fiber tension, thereby saving the cost associated with the force sensor.

[0100] Example 6

[0101] The difference between Example 6 and Example 1 is that the 9 laser displacement sensor is no longer provided.

[0102] In the case of setting a constant force device, as long as the displacement of the constant force device is within the allowable displacement range, the fiber tension is basically constant (within the allowable error range). Conversely, as long as the fiber tension is basically constant (within the allowable error range), the displacement of the constant force device is within the allowable displacement range. Therefore, it is only necessary to use a movable pulley with a force sensor to obtain the force of the constant force device to know the fiber tension. The rotation speed of the core shaft 2 is adjusted according to the measured value of the force sensor so that the fiber tension remains constant, and a laser displacement sensor is no longer needed to measure the displacement of the constant force device, thereby saving the cost associated with the displacement sensor.

[0103] Example 7

[0104] Embodiment 7 The constant force device adopts another type of constant force unit. The structural diagram of the constant force device is as follows: Fig.12 , including: 5-1 a first surface, 5-2 a second surface, 5-3 a constant force unit, and 5-4 a guide tube.

[0105] Among them, the first surface 5-1 is parallel to the second surface 5-2.

[0106] Among them, the guide tube 5-4 is fixedly arranged in the middle position of the second surface 5-2, and the first surface 5-1 is slidably connected with the guide tube 5-4, so that the first surface 5-1 can move up and down along the guide tube 5-4.

[0107] The constant force unit 5-3 is composed of four identical inclined thin sheets, and a bending portion 5-5 is arranged near the second plane of the constant force unit 5-3. The angle between the inclined thin sheet and the upper surface of 5-1 is 60 degrees.

[0108] When the upper surface of the constant force device moves downward under pressure, the constant force unit is compressed, and each constant force unit may bend inward or outward, which may cause the two constant force units to contact each other during bending and deformation, thereby affecting the free deformation of each constant force unit and further affecting the force performance of the entire constant force device. The purpose of setting the bending portion is to guide the direction of the constant force unit's bending deformation under pressure, so that all constant force units deform in one direction without contact, that is, they all bend outward or inward, so that the deformation and force performance of the constant force unit are more controllable.

[0109] Example 8

[0110] Embodiment 8 The constant force device adopts another type of constant force unit. The structural diagram of the constant force device is as follows: Fig.13 , including: 5-1 a first surface, 5-2 a second surface, 5-3 a constant force unit, and 5-4 a guide tube.

[0111] Among them, the first surface 5-1 is parallel to the second surface 5-2.

[0112] Among them, the guide tube 5-4 is fixedly arranged in the middle position of the second surface 5-2, and the first surface 5-1 is slidably connected with the guide tube 5-4, so that the first surface 5-1 can move up and down along the guide tube 5-4.

[0113] Among them, the 5-3 constant force unit is composed of 4 identical inclined thin sheets, and the axis of each constant force unit is in the form of a curve that bulges outward.

[0114] The angle between the line between the upper end of the inclined sheet and the lower end of the inclined sheet and the upper surface of 5-1 is 64 degrees.

[0115] 5-3 The purpose of the outward-bending curve of the axis of the constant force unit is to guide all the constant force units to bend outward when under pressure without contacting each other, so that the deformation and force performance of the constant force device are more controllable.

[0116] Example 9

[0117] Example 9 illustrates another form of the constant force unit in the constant force device.

[0118] Modal analysis is performed on the inclined constant force unit with a straight axis to obtain the buckling deformation curve. The deformation amount of each point on the deformation curve is selected according to a certain proportion to obtain a series of different deformation curve forms. These curve forms can be used as the design form of the constant force unit, such as Fig.14 .

[0119] Fig.14 The initial shape, the buckling deformation curve of the modal analysis, the 0.1 times buckling deformation curve, and the 0.4 times buckling deformation curve are shown as examples.

[0120] According to the specific materials, geometric dimensions, design space and other factors of the constant force unit, the proportional coefficient is determined to obtain an efficient and reliable constant force unit form.

Claims

1. A constant tension fiber winding device and a control method thereof, characterized in that: The device comprises motor 1 and motor 2, core shaft 1 and core shaft 2, fixed pulley 1 and fixed pulley 2, a movable pulley with a force sensor, a constant force device, a sensor and a feedback controller, and a base, wherein core shaft 1 and core shaft 2 are fixed on the base, motor 1 controls the rotation speed of core shaft 1, and motor 2 controls the rotation speed of core shaft 2; the constant force device is arranged between core shaft 1 and core shaft 2; the movable pulley with the force sensor is arranged on the upper part of the constant force device, and fixed pulley 1 and fixed pulley 2 are fixedly arranged on both sides of the constant force device; the fiber is pulled out from core shaft 1, passes through fixed pulley 1, the movable pulley with the force sensor and fixed pulley 2 in sequence, and then is wound on core shaft 2; the sensor performs real-time measurement on the constant force device, and when the measurement value of the constant force device exceeds a preset range, the feedback controller controls motor 2 to change the rotation speed of core shaft 2, so that the measurement value of the constant force device is within the preset range.

2. The constant tension fiber winding device and control method thereof according to claim 1, characterized in that: The constant force device is optimized in design so that when the constant force device is subjected to pressure, it outputs constant force within a certain displacement range.

3. The constant tension fiber winding device and control method thereof according to claim 2, characterized in that: The constant force device comprises a first surface, a second surface, a guide tube, and a constant force unit between the first surface and the second surface.

4. The constant tension fiber winding device and control method thereof according to claim 3, characterized in that: The first surface is parallel to the second surface, the second surface is fixedly arranged on the base, the guide tube has a smooth surface and is fixedly arranged in the middle of the second surface, the first surface is slidably connected to the guide tube, so that the first surface can move up and down along the guide tube.

5. The constant tension fiber winding device and control method thereof according to claim 3, characterized in that: The constant force unit includes one or more inclined slender columns or inclined thin sheets.

6. The constant tension fiber winding device and control method thereof according to claim 5, characterized in that: The constant force unit is preferably an inclined lamellar body.

7. The constant tension fiber winding device and control method thereof according to claim 5, characterized in that: The slenderness ratio of the constant force unit is >10.

8. The constant tension fiber winding device and control method thereof according to claim 5, characterized in that: The axis of the constant force unit is a straight line.

9. The constant tension fiber winding device and control method thereof according to claim 5, characterized in that: The axis of the constant force unit is a curved line.

10. The constant tension fiber winding device and control method thereof according to claim 5, characterized in that: The constant force unit is provided with one or more bending portions near the first surface / the second surface.

11. The constant tension fiber winding device and control method thereof according to claim 5, characterized in that: The angle between the intersection point of the constant force unit and the first surface, and the intersection point of the constant force unit and the second surface, and the line connecting the two intersection points and the first surface or the second surface is 50-130°.

12. The constant tension fiber winding device and control method thereof according to claim 5, characterized in that: The constant force units are arranged symmetrically in pairs.

13. The constant tension fiber winding device and control method thereof according to claim 1, characterized in that: The sensor adopts displacement sensor.

14. The constant tension fiber winding device and control method thereof according to claim 1, characterized in that: The sensor adopts a force sensor.

15. The constant tension fiber winding device and control method thereof according to claim 13, characterized in that: The displacement sensor adopts a laser displacement sensor.

16. The constant tension fiber winding device and control method thereof according to claim 1, characterized in that: The feedback controller adopts a PID controller (proportional-integral-differential controller).

17. The constant tension fiber winding device and control method thereof according to claim 1, characterized in that: The feedback controller adopts a fuzzy controller.

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