A tension control method for ceramic matrix composite fiber tows

Abstract

The present application relates to the technical field of industrial prepreg production equipment, and specifically discloses a tension control method for ceramic matrix composite fiber tows, wherein the ceramic matrix composite fiber tows are laid and impregnated by a fiber laying machine, the fiber laying machine comprises a fiber unwinding roller for releasing the fiber tows and a fiber winding roller for winding the fiber tows, and the tension balance of the fiber tows during the fiber unwinding and winding processes of the fiber laying machine is realized by controlling the rotating speeds of the fiber unwinding roller and the fiber winding roller. In the present application, a servo motor is used to replace a magnetic powder brake to control the tension, thus effectively avoiding the problem that the magnetic powder brake cannot control the tension less than the resistance range of the magnetic powder brake. The fiber unwinding roller and the fiber winding roller are both controlled by servo motors, a double closed-loop control mode is adopted, the tension control is realized by adjusting the speed difference between the fiber unwinding roller and the fiber winding roller, the tension control range is improved, the stability is better, the resistance influencing factors are avoided, and the signal oscillation problem caused by one-way control is optimized.

Description

Technical Field

[0001] This invention relates to the field of industrial prepreg production equipment technology, specifically to a tension control method for fiber bundles of ceramic matrix composites. Background Technology

[0002] Fiber laying machines are key pieces of equipment in the production of prepregs for the aerospace and electronics industries. They can be used to produce non-woven fabrics from prepregs such as carbon fiber, high-molecular-weight PE fiber, and aramid fiber. Existing technology uses a servo motor to synchronize the fiber running linear speed, feeding the yarn at low tension and pre-tightening it at high tension. To eliminate the influence of unilateral tension during yarn unwinding, a yarn unwinding tension control device is constructed, consisting of an unwinding roll, an arc-shaped guide rod, a centering roller, a tension-relieving wheel assembly, and a tension control wheel assembly.

[0003] Currently, there is a need to use SiC fiber filaments, a new material, to produce related industrial prepregs using fiber laying machines. However, due to the brittle nature of SiC fiber filaments, existing fiber laying machines are prone to oscillations during the laying process due to the commutation of servo motors, which leads to unstable tension control and, consequently, fiber breakage during tension adjustment. Summary of the Invention

[0004] The purpose of this invention is to provide a tension control method for ceramic matrix composite fiber bundles that provides stable tension control and improves tension control accuracy.

[0005] The present invention is achieved through the following technical solution: a tension control method for fiber bundles of ceramic matrix composite materials, wherein the fiber bundles of ceramic matrix composite materials are laid out and impregnated by a fiber laying machine, the fiber laying machine including an unwinding roller for releasing the fiber bundles and a winding roller for taking up the fiber bundles, and tension balance of the fiber bundles during the unwinding and winding processes of the fiber laying machine is achieved by controlling the rotation speed of the unwinding roller and the winding roller.

[0006] To better implement the method of the present invention, the fiber laying machine further includes a guide buffer, an impregnation assembly, a guide roller, and an extrusion roller arranged sequentially between the unwinding roller and the take-up roller. The impregnation assembly is placed in a glue tank containing glue liquid. The ceramic matrix composite fiber bundle is released by the unwinding roller, buffered and guided by the guide buffer, impregnated in the glue tank by the impregnation assembly, guided by the guide roller and removed by the extrusion roller, and finally taken up by the take-up roller.

[0007] To better implement the method of the present invention, the rotational speeds of the unwinding roller and the take-up roller are further controlled by a tension control system. The tension control system includes a first speed control loop for controlling the rotational speed of the unwinding roller and a second speed control loop for controlling the rotational speed of the take-up roller. The first speed control loop and the second speed control loop are correlated in speed by a tension logic arithmetic unit.

[0008] To better implement the method of the present invention, the first speed control loop further includes a first PID controller, a first linear velocity sensor, and a first servo motor; the second speed control loop includes a second PID controller, a second linear velocity sensor, and a second servo motor; the first linear velocity sensor detects the actual unwinding speed of the filament bundle between the unwinding roller and the guide buffer, the second linear velocity sensor detects the actual winding speed of the filament bundle between the extrusion roller and the winding roller, the first servo motor controls the rotational speed of the unwinding roller, and the second servo motor controls the rotational speed of the winding roller.

[0009] To better implement the method of the present invention, the process of controlling the rotational speed of the unwinding roller and the take-up roller through the tension control system further includes the following steps:

[0010] Step S1: Based on the physical properties of the ceramic matrix composite fiber bundles, set the theoretical tension T of the ceramic matrix composite fiber bundles on the fiber laying machine, and the theoretical unwinding speed V of the ceramic matrix composite fiber bundles on the fiber laying machine. 放 The theoretical tension T is not greater than the ultimate tension that the fiber bundle of the ceramic matrix composite material can withstand;

[0011] Step S2: Detect the actual unwinding speed V1 of the yarn bundle between the unwinding roller and the guide buffer using the first speed sensor, and compare the actual unwinding speed V1 with the theoretical unwinding speed V... 放 The absolute value of the difference, E1, is input to the first PID controller. The first PID controller controls the first servo motor, which in turn controls the rotational speed of the unwinding roller, thus directing the actual unwinding speed V1 towards the theoretical unwinding speed V. 放 Size adjustment;

[0012] Step S3: Input the actual unwinding speed V1 detected by the first speed sensor into the tension logic operator. The tension logic operator can run the tension calculation formula of the fiber bundle and calculate the theoretical winding speed V2 of the winding roller based on V1 according to the parameters of the fiber bundle and the set theoretical tension T.

[0013] Step S4: The actual take-up speed V2' of the filament bundle between the extrusion roller and the take-up roller is detected by the second speed sensor. The absolute value E2 of the difference between the actual take-up speed V2' and the theoretical take-up speed V2 based on V1 is input to the second PID controller. The second PID controller controls the second servo motor and uses the second servo motor to control the rotation speed of the take-up roller, so that the actual take-up speed V2' is adjusted to the magnitude of the theoretical take-up speed V2 based on V1.

[0014] Step S5: The first speed sensor and the second sensor periodically detect the unwinding or winding speed of the fiber bundle, so that the first PID controller and the second PID controller periodically send instructions to the first servo motor and the second servo motor. The first servo motor and the second servo motor realize the real-time dynamic adjustment of the rotation speed of the unwinding roller and the winding roller, so that the tension of the ceramic matrix composite fiber bundle on the fiber laying machine is always the theoretical tension T.

[0015] To better implement the method of the present invention, the tension calculation formula for the fiber bundle operated by the tension logic operator is further as follows:

[0016]

[0017] Where T is the theoretical tension T of the fiber bundle on the fiber laying machine, S is the cross-sectional area of ​​the fiber bundle, L is the length of the fiber bundle, E is the elastic modulus of the fiber bundle, and t is time.

[0018] To better implement the method of the present invention, the parameters of the first PID controller and the second PID controller further include the proportional coefficient Kp, the integral time TN, and the derivative time TV, all of which are obtained by the critical oscillation method.

[0019] To better implement the method of the present invention, the specific process of obtaining the parameters of the first PID controller and the second PID controller by the critical oscillation method is as follows:

[0020] First, eliminate the integral and derivative effects in the PID controller, that is, maximize the integral time and zero the derivative time. Introduce a step change using external disturbances and observe the resulting oscillations in the measured value. Gradually decrease the proportional gain from large to small, observing the changes in the measured value oscillations. If the oscillation is decaying, continue decreasing the proportional gain; if it is diverging, increase the proportional gain. Continue until the measured value exhibits 4-5 equal-amplitude oscillations. The proportional gain at this point is the critical proportional gain Kb, and the time for one oscillation is the critical period Kt. Based on the critical proportional gain and critical period, calculate the integral and derivative times using the Ziegler-Nichols method: Kp = 0.6 * Kb, TN = 0.5 * Kt, TV = 0.125 * Kt.

[0021] To better implement the method of the present invention, the second PID controller is further defined as an incremental PID controller.

[0022] To better implement the method of the present invention, it is further characterized by including step S6: evaluating the tension control effect, specifically as follows:

[0023] S61: Based on the formula for calculating the tension of the fiber bundle, the theoretical tension T of the fiber bundle, and the theoretical unwinding speed V of the fiber bundle. 放 The theoretical take-up speed V of the fiber bundle was calculated. 收 ;

[0024] S62: The theoretical take-up speed V 收 The absolute value of the difference between the actual take-up speed V2' and E3 is used as an evaluation index for the tension control effect;

[0025] S63: The smaller the E3 value, the better the tension control effect; conversely, the larger the E3 value, the worse the tension control effect.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] (1) In view of the easy breakage characteristics of SiC fiber, the present invention uses servo motor control to control the speed of the unwinding roller and the take-up roller respectively. By adjusting the speed of the two servo motors, the tension of the fiber bundle is controlled, so that the tension is stably controlled.

[0028] (2) The tension control method provided by the present invention replaces the tension control method using a magnetic powder brake, which can achieve small tension control, improve the tension control range to 0-100N, and has better control stability and high control accuracy, reaching ±5%, effectively avoiding the problem that the magnetic powder brake itself has high resistance and cannot control the tension below the resistance range.

[0029] (3) The present invention adopts a dual closed-loop control mode, which uses a PID regulator to control two servo motors. The tension control is achieved by adjusting the speed difference between the unwinding roller and the take-up roller through the two servo motors. This avoids the problem of wire breakage caused by servo motor commutation when a single servo motor is controlled, and is suitable for widespread application. Attached Figure Description

[0030] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0031] Figure 1 This is a schematic diagram of the fiber bundle control structure in this invention;

[0032] Figure 2This is a flowchart of the specific control method of the present invention;

[0033] Figure 3 This is a three-dimensional structural diagram of the guide buffer of the fiber laying machine in this invention.

[0034] Wherein: 1—unwinding roller, 2—guide buffer, 21—upper frame, 22—lower frame, 23—spring guide post, 24—filament guide wheel, 25—support plate, 26—limiting roller, 3—impregnation assembly, 4—glue tank, 5—guide roller, 6—extrusion roller, 7—wind take-up roller. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, the terms "first" and "second" are limited to descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly including one or more of the feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Example 1:

[0039] This embodiment provides a tension control method for fiber bundles of ceramic matrix composites. The fiber bundles of ceramic matrix composites are laid out and impregnated by a fiber laying machine. The fiber laying machine includes an unwinding roller 1 for releasing the fiber bundles and a winding roller 7 for taking back the fiber bundles. The method is characterized in that the tension balance of the fiber bundles during the unwinding and winding processes of the fiber laying machine is achieved by controlling the rotational speed of the unwinding roller 1 and the winding roller 7.

[0040] Example 2:

[0041] This embodiment further defines the structure of the fiber laying machine based on the above embodiments, such as... Figure 1 As shown, the fiber laying machine also includes a guide buffer 2, an impregnation assembly 3, a guide roller 5, and an extrusion roller 6 arranged sequentially between the unwinding roller 1 and the take-up roller 7. The impregnation assembly 3 is placed in a glue tank 4 containing glue liquid. The ceramic matrix composite fiber bundle is released through the unwinding roller 1, buffered and guided by the guide buffer 2, impregnated in the glue tank 4 by the impregnation assembly 3, guided by the guide roller 5 and the glue extrusion roller 6 removing excess glue liquid, and finally taken up by the take-up roller 7.

[0042] The dipping assembly 3 consists of at least two dipping rollers placed parallel to each other in the glue tank 4.

[0043] Example 3:

[0044] This embodiment, based on the above embodiment, further limits the rotational speeds of the unwinding roller 1 and the take-up roller 7 to be controlled by a tension control system, such as... Figure 1 As shown, the tension control system includes a first speed control loop that controls the rotational speed of the unwinding roller 1 and a second speed control loop that controls the rotational speed of the take-up roller 7. The first speed control loop and the second speed control loop are correlated in speed through a tension logic arithmetic unit.

[0045] The first speed control loop includes a first PID controller, a first linear velocity sensor, and a first servo motor; the second speed control loop includes a second PID controller, a second linear velocity sensor, and a second servo motor; the first linear velocity sensor detects the actual unwinding speed of the filament bundle between the unwinding roller 1 and the guide buffer 2, the second linear velocity sensor detects the actual winding speed of the filament bundle between the extrusion roller 6 and the winding roller 7, the first servo motor controls the rotational speed of the unwinding roller 1, and the second servo motor controls the rotational speed of the winding roller 7.

[0046] Example 4:

[0047] This embodiment, based on the above embodiments, further specifies the specific process of controlling the rotational speeds of the unwinding roller 1 and the take-up roller 7 through the tension control system, such as... Figure 2 As shown, it includes the following steps:

[0048] Step S1: Based on the physical properties of the ceramic matrix composite fiber bundles, set the theoretical tension T of the ceramic matrix composite fiber bundles on the fiber laying machine, and the theoretical unwinding speed V of the ceramic matrix composite fiber bundles on the fiber laying machine. 放 The theoretical tension T is not greater than the ultimate tension that the fiber bundle of the ceramic matrix composite material can withstand;

[0049] Step S2: The actual unwinding speed V1 of the yarn bundle between the unwinding roller 1 and the guide buffer 2 is detected by the first speed sensor, and the actual unwinding speed V1 is compared with the theoretical unwinding speed V. 放 The absolute value of the difference, E1, is input to the first PID controller. The first PID controller controls the first servo motor, which in turn controls the rotational speed of the unwinding roller 1, thus directing the actual unwinding speed V1 towards the theoretical unwinding speed V. 放 Size adjustment;

[0050] Step S3: Input the actual unwinding speed V1 detected by the first speed sensor into the tension logic operator. The tension logic operator can run the tension calculation formula of the fiber bundle and calculate the theoretical winding speed V2 of the winding roller 7 based on V1 according to the parameters of the fiber bundle and the set theoretical tension T.

[0051] Step S4: The actual take-up speed V2' of the filament bundle between the extrusion roller 6 and the take-up roller 7 is detected by the second speed sensor. The absolute value E2 of the difference between the actual take-up speed V2' and the theoretical take-up speed V2 based on V1 is input to the second PID controller. The second PID controller controls the second servo motor and uses the second servo motor to control the rotation speed of the take-up roller 7, so that the actual take-up speed V2' is adjusted to the magnitude of the theoretical take-up speed V2 based on V1.

[0052] Step S5: The first speed sensor and the second sensor periodically detect the unwinding or winding speed of the fiber bundle, so that the first PID controller and the second PID controller periodically send instructions to the first servo motor and the second servo motor. The first servo motor and the second servo motor realize the real-time dynamic adjustment of the rotation speed of the unwinding roller 1 and the winding roller 2, so that the tension of the ceramic matrix composite fiber bundle on the fiber laying machine is always the theoretical tension T.

[0053] Step S6: Evaluate the tension control effect, specifically as follows:

[0054] S61: Based on the formula for calculating the tension of the fiber bundle, the theoretical tension T of the fiber bundle, and the theoretical unwinding speed V of the fiber bundle. 放 The theoretical take-up speed V of the fiber bundle was calculated. 收 ;

[0055] S62: The theoretical take-up speed V 收 The absolute value of the difference between the actual take-up speed V2' and E3 is used as an evaluation index for the tension control effect;

[0056] S63: The smaller the E3 value, the better the tension control effect; conversely, the larger the E3 value, the worse the tension control effect.

[0057] Example 5:

[0058] Based on the above embodiments, this embodiment further defines the tension calculation formula for the fiber bundle operated by the tension logic operator as follows:

[0059]

[0060] Where T is the theoretical tension T of the fiber bundle on the fiber laying machine, S is the cross-sectional area of ​​the fiber bundle, L is the length of the fiber bundle, E is the elastic modulus of the fiber bundle, and t is time.

[0061] Example 6:

[0062] Based on the above embodiments, this embodiment further defines the parameters of the first PID controller and the second PID controller as including the proportional coefficient Kp, integral time TN, and derivative time TV, wherein the proportional coefficient Kp, integral time TN, and derivative time TV are all obtained by the critical oscillation method.

[0063] The specific process of obtaining the parameters of the first PID controller and the second PID controller using the critical oscillation method is as follows:

[0064] First, eliminate the integral and derivative effects in the PID controller, that is, maximize the integral time and zero the derivative time. Introduce a step change using external disturbances and observe the resulting oscillations in the measured value. Gradually decrease the proportional gain from large to small, observing the changes in the measured value oscillations. If the oscillation is decaying, continue decreasing the proportional gain; if it is diverging, increase the proportional gain. Continue until the measured value exhibits 4-5 equal-amplitude oscillations. The proportional gain at this point is the critical proportional gain Kb, and the time for one oscillation is the critical period Kt. Based on the critical proportional gain and critical period, calculate the integral and derivative times using the Ziegler-Nichols method: Kp = 0.6 * Kb, TN = 0.5 * Kt, TV = 0.125 * Kt.

[0065] Example 7:

[0066] This embodiment, based on the above embodiments, further defines the second PID controller as an incremental PID controller. An incremental PID controller is a PID controller that controls the system by calculating the increment of the control quantity. This method primarily focuses on the increment of the control quantity, combining proportional, integral, and derivative control to achieve rapid response and stable control of the system, avoiding the cumulative effect of the integral term, thereby reducing computational performance and storage space requirements.

[0067] Example 8:

[0068] This embodiment, based on the above embodiment, further defines the specific structure of the guide wire buffer 2, such as... Figure 3 As shown, the fiber guide buffer 2 includes an upper frame 21 and a lower frame 22. Several spring guide posts 23 are arranged between the upper frame 21 and the lower frame 22. The upper frame 21 can reciprocate up and down above the lower frame 22. A rotatable fiber guide wheel 24 is installed on the upper frame 21. A support plate 25 is fixed to one side of the lower frame 22, and two parallel limiting rollers 26 are fixedly arranged on the upper part of the support plate 25. The fiber bundle is released into the fiber guide buffer 2 through the unwinding roller 1, first passing between the two parallel limiting rollers 26, and then passing through the fiber guide wheel 24 on the upper frame 21. When the fiber bundle tension increases sharply, the upper frame 21 compresses the spring guide posts 23 downwards; when the fiber tension decreases, the spring guide posts 23 push the upper frame 21 upwards to counteract the sudden tension change and maintain constant tension. After passing through the fiber guide wheel 24, the fiber bundle enters the glue tank.

[0069] Before the composite fiber bundles released from the feeding roller 1 are impregnated with resin, they need to be guided by the guide roller to ensure that the fiber bundles run in a straight line in the center. However, due to the easy-to-break characteristics of the new material SiC fiber, the fiber bundles are very prone to breakage at the guide roller, resulting in large tension fluctuations, poor finished product quality, and high scrap rate.

[0070] Analysis revealed that the large variation in the exit angle of the composite fiber bundles from the unwinding roller 1 resulted in significant tension fluctuations, making the bundles prone to breakage at the guide post. This also affected the fiber tension control accuracy of the entire process, failing to meet the process requirements.

[0071] After in-depth research into the problems of fiber breakage and large tension fluctuations on-site, it was found that the fiber exit angle gradually increases and then decreases in a cyclical manner. The tension fluctuations of the fiber bundles collected by the tension sensor also follow the same pattern, and fiber breakage is prone to occur at the peak of the angle transition. Therefore, the traditional guide roller was improved.

[0072] The overall frame structure was split into upper and lower parts without changing the original structural form. At the same time, spring guide posts 23 were added as elastic units in the limited space. When the fiber tension increases, the elastic unit is compressed downwards, and when the fiber tension decreases, the elastic unit is lifted upwards to counteract the sudden change in tension and maintain constant tension.

[0073] Judging from the product quality and process effect after installing the improved wire guide buffer 2, the improved wire guide buffer 2 eliminates the peak point of tension fluctuation, improves the tension control accuracy from 10% to 3%, significantly improves the quality of finished products, greatly reduces the number of composite fiber breakages, improves production efficiency, and saves maintenance costs.

[0074] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for tension control of fiber bundles in ceramic matrix composites, wherein the fiber bundles are laid out and impregnated by a fiber laying machine, the fiber laying machine comprising an unwinding roller (1) for releasing the fiber bundles and a winding roller (7) for taking up the fiber bundles, characterized in that, The tension balance of the fiber bundle during the unwinding and winding process of the fiber laying machine is achieved by controlling the rotation speed of the unwinding roller (1) and the winding roller (7). The fiber laying machine also includes a guide buffer (2), an impregnation assembly (3), a guide roller (5), and an extrusion roller (6) arranged sequentially between the unwinding roller (1) and the take-up roller (7). The impregnation assembly (3) is placed in a glue tank (4) containing glue. The ceramic matrix composite fiber bundle is released through the unwinding roller (1), buffered and guided by the guide buffer (2), impregnated in the glue tank (4) by the impregnation assembly (3), guided by the guide roller (5), and the excess glue is removed by the extrusion roller (6). Finally, it is taken up by the take-up roller (7). The rotation speed of the unwinding roller (1) and the take-up roller (7) is controlled by a tension control system. The tension control system includes a first speed control loop that controls the rotation speed of the unwinding roller (1). The first speed control ring and the second speed control ring are connected by a tension logic arithmetic unit to control the rotation speed of the take-up roller (7). The first speed control ring includes a first PID controller, a first linear speed sensor, and a first servo motor. The second speed control ring includes a second PID controller, a second linear speed sensor, and a second servo motor. The first linear speed sensor detects the actual unwinding speed of the filament between the unwinding roller (1) and the guide buffer (2). The second linear speed sensor detects the actual take-up speed of the filament between the extrusion roller (6) and the take-up roller (7). The first servo motor controls the rotation speed of the unwinding roller (1), and the second servo motor controls the rotation speed of the take-up roller (7). The process of controlling the rotational speed of the unwinding roller (1) and the take-up roller (7) through the tension control system includes the following steps: Step S1: Based on the physical properties of the ceramic matrix composite fiber bundles, set the theoretical tension T of the ceramic matrix composite fiber bundles on the fiber laying machine, and the theoretical unwinding speed V of the ceramic matrix composite fiber bundles on the fiber laying machine. 放 The theoretical tension T is not greater than the ultimate tension that the fiber bundle of the ceramic matrix composite material can withstand; Step S2: The actual unwinding speed V1 of the yarn bundle between the unwinding roller (1) and the guide buffer (2) is detected by the first speed sensor, and the actual unwinding speed V1 is compared with the theoretical unwinding speed V 放 The absolute value of the difference, E1, is input to the first PID controller. The first PID controller controls the first servo motor, which controls the rotational speed of the unwinding roller (1), thereby adjusting the actual unwinding speed V1 towards the theoretical unwinding speed V. 放 Size adjustment; Step S3: Input the actual unwinding speed V1 detected by the first speed sensor into the tension logic operator. The tension logic operator can run the tension calculation formula of the fiber bundle and calculate the theoretical winding speed V2 of the winding roller (7) based on V1 according to the parameters of the fiber bundle and the set theoretical tension T. Step S4: The actual take-up speed V2' of the filament bundle between the extrusion roller (6) and the take-up roller (7) is detected by the second speed sensor. The absolute value E2 of the difference between the actual take-up speed V2' and the theoretical take-up speed V2 based on V1 is input to the second PID controller. The second PID controller controls the second servo motor and uses the second servo motor to control the rotation speed of the take-up roller (7), so that the actual take-up speed V2' is adjusted to the magnitude of the theoretical take-up speed V2 based on V1. Step S5: The first speed sensor and the second sensor periodically detect the unwinding or winding speed of the fiber bundle, so that the first PID controller and the second PID controller periodically send instructions to the first servo motor and the second servo motor. The first servo motor and the second servo motor realize the real-time dynamic adjustment of the rotation speed of the unwinding roller (1) and the winding roller (2), so that the tension of the ceramic matrix composite fiber bundle on the fiber laying machine is always the theoretical tension T.

2. The tension control method for fiber bundles in ceramic matrix composites according to claim 1, characterized in that, The tension calculation formula for the fiber bundle operated by the tension logic operator is as follows: Where T is the theoretical tension T of the fiber bundle on the fiber laying machine, S is the cross-sectional area of ​​the fiber bundle, L is the length of the fiber bundle, E is the elastic modulus of the fiber bundle, and t is time.

3. The tension control method for fiber bundles in ceramic matrix composites according to claim 1, characterized in that, The parameters of the first PID controller and the second PID controller include the proportional coefficient Kp, the integral time TN, and the derivative time TV. The proportional coefficient Kp, the integral time TN, and the derivative time TV are all obtained by the critical oscillation method.

4. The tension control method for fiber bundles in ceramic matrix composites according to claim 3, characterized in that, The specific process of obtaining the parameters of the first PID controller and the second PID controller using the critical oscillation method is as follows: First, eliminate the integral and derivative effects in the PID controller, that is, maximize the integral time and zero the derivative time. Introduce a step change using external disturbances and observe the resulting oscillations in the measured value. Gradually decrease the proportional gain from large to small, observing the changes in the measured value oscillations. If the oscillation is decaying, continue decreasing the proportional gain; if it is diverging, increase the proportional gain. Continue until the measured value exhibits 4-5 equal-amplitude oscillations. The proportional gain at this point is the critical proportional gain Kb, and the time for one oscillation is the critical period Kt. Based on the critical proportional gain and critical period, calculate the integral and derivative times using the Ziegler-Nichols method: Kp = 0.6 * Kb, TN = 0.5 * Kt, TV = 0.125 * Kt.

5. The tension control method for fiber bundles in ceramic matrix composites according to claim 4, characterized in that, The second PID controller is an incremental PID controller.

6. A method for tension control of fiber bundles in ceramic matrix composites according to any one of claims 1 to 5, characterized in that, It also includes step S6: evaluating the tension control effect, specifically: S61: Based on the formula for calculating the tension of the fiber bundle, the theoretical tension T of the fiber bundle, and the theoretical unwinding speed V of the fiber bundle. 放 The theoretical take-up speed V of the fiber bundle was calculated. 收 ; S62: The theoretical take-up speed V 收 The absolute value of the difference between the actual take-up speed V2' and E3 is used as an evaluation index for the tension control effect; S63: The smaller the E3 value, the better the tension control effect; conversely, the larger the E3 value, the worse the tension control effect.

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