A composite rod winding tension dynamic compensation control method and system

Abstract

The present application relates to the technical field of manufacturing unit control, and particularly relates to a composite rod winding tension dynamic compensation control method and system. The method comprises the following steps: calculating the instantaneous linear velocity fluctuation caused by the non-circular cross-section profile change of the mandrel at each moment; calculating a phase correction factor for representing the viscoelastic response lag of the prepreg tape at each moment according to the dynamic elastic modulus and the equivalent viscous coefficient; obtaining a dynamic compensation torque instruction based on the instantaneous linear velocity fluctuation and the phase correction factor at each moment, the dynamic compensation torque instruction being negatively related to the phase correction factor; and outputting the dynamic compensation torque instruction to a tension unwinding motor to adjust the winding tension, thereby effectively improving the accuracy of the tension dynamic compensation control and the quality of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of control of manufacturing units, in particular to a composite rod winding tension dynamic compensation control method and system. BACKGROUND

[0002] In the field of composite rod manufacturing, especially for non-circular cross-section components such as square tubes, carbon fiber winding technology is widely used because it can achieve high strength and high tightness characteristics of the product. The horizontal dry winding machine mainly softens the prepreg tape to a viscous flow state through the heating system, and then under the constraint of the tension control system, it is precisely wound onto the surface of the rotating core mold.

[0003] In the winding process of square tube rods, since the core mold cross-section is non-circular, when the core mold rotates at a constant angular velocity, the polar radius of the fiber contact point to the center axis will change periodically and dramatically with the rotation angle. This mutation of geometric characteristics leads to the pulsation of the instantaneous linear velocity of fiber winding, which in turn causes the dramatic fluctuation of tension.

[0004] To suppress such fluctuations, the existing technology mainly uses a tension feedforward compensation algorithm based on a pure geometric model, that is, the theoretical linear velocity pulsation is calculated according to the geometric size and motion state of the core mold to compensate. However, in the dry winding scene, the prepreg tape shows significant viscoelastic mechanical characteristics after being heated, which means that the establishment and disappearance of tension is not instantaneous, but there is a response lag limited by the movement of material molecular chains. The traditional pure geometric control algorithm does not consider this phase shift caused by the thermal properties of the material, resulting in a misalignment of the calculated compensation signal and the actual physical demand on the time axis, which causes tension shock, causing the fiber to relax or be crushed at the corners of the square tube, seriously affecting product quality. SUMMARY

[0005] In order to solve the technical problem that the calculated compensation signal and the actual physical demand are misaligned on the time axis, causing tension shock, the present application provides a composite rod winding tension dynamic compensation control method and system.

[0006] In the first aspect, the present application provides a composite rod winding tension dynamic compensation control method, which adopts the following technical scheme:

[0007] A composite rod winding tension dynamic compensation control method, comprising the steps of:

[0008] The rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotation angle are acquired; the instantaneous linear speed fluctuation amount caused by the non-circular cross-section profile change of the mandrel at each moment is calculated, and the instantaneous linear speed fluctuation amount is positively correlated with the rotational angular velocity, the real-time polar radius and the axial movement speed; the dynamic elastic modulus and the equivalent viscous coefficient of the prepreg tape at each moment are acquired, and the phase correction factor for representing the viscoelastic response lag of the prepreg tape at each moment is calculated according to the dynamic elastic modulus and the equivalent viscous coefficient, and the phase correction factor is negatively correlated with the dynamic elastic modulus and positively correlated with the equivalent viscous coefficient; the dynamic compensation torque instruction is obtained based on the instantaneous linear speed fluctuation amount and the phase correction factor at each moment, and the dynamic compensation torque instruction is negatively correlated with the phase correction factor; and the dynamic compensation torque instruction is output to the tension unwinding motor, so that the winding tension is adjusted.

[0009] The present application solves the phase shift problem caused by the traditional pure geometric control algorithm without considering the thermal state properties of the material by acquiring the motion state and geometric parameters of the rotating mandrel in real time, calculating the instantaneous linear speed fluctuation amount caused by the non-circular cross-section profile change, and introducing the phase correction factor in combination with the dynamic elastic modulus and the equivalent viscous coefficient of the prepreg tape. In addition, the present application combines the linear speed fluctuation obtained by kinematic analysis with the material lag obtained by dynamic correction to generate a dynamic compensation torque instruction, realizes the accurate coincidence of the compensation signal and the actual physical demand on the time axis, effectively suppresses the tension shock in the winding process of the square tube and other non-circular members, effectively reduces the possibility of fiber relaxation or bruising, and thus effectively improves the product quality.

[0010] According to the composite rod winding tension dynamic compensation control method provided by the present application, the rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotation angle are acquired, including: acquiring the geometric parameters of the mandrel through the man-machine interaction interface, including the side length and the chamfer radius; acquiring the rotation angle and the rotation angular velocity of the mandrel through the main shaft encoder; and acquiring the horizontal movement of the nozzle through the displacement sensor and calculating the axial movement speed.

[0011] According to the composite rod winding tension dynamic compensation control method provided by the present application, the rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotation angle are acquired, including:

[0012] ;

[0013] is the real-time polar radius at the first time, is the side length of the mandrel, is the rotation angle of the mandrel at the first time, is the cosine function, The value is calculated by taking the modulo of the rotation angle.

[0014] This invention provides a real-time extreme diameter calculation method based on cosine function and modulus operation, which can accurately describe the dynamic distance change from the fiber contact point to the central axis during the rotation of the square tube mandrel. In particular, for the geometric abrupt change characteristics of alternating edges and planes, an accurate dynamic model of the winding trajectory is established, thus providing a mathematical basis for accurately evaluating the periodic pulsation of linear velocity caused by the non-circular characteristics of the cross section.

[0015] According to the present invention, a dynamic compensation control method for the winding tension of composite material rods is provided, wherein calculating the instantaneous linear velocity pulsation caused by the change in the non-circular cross-sectional profile of the mandrel at each moment includes:

[0016] ;

[0017] , , , The first Instantaneous linear velocity pulsation, rotational angular velocity, real-time extreme diameter, and axial movement speed of the nozzle at any given moment. This is the preset linear velocity.

[0018] This invention synthesizes the rotational tangential velocity and axial movement velocity, and calculates the instantaneous linear velocity pulsation, which can evaluate the velocity fluctuation amplitude of the fiber in three-dimensional space caused by the change of the non-circular cross-sectional profile. By comparing the synthesized linear velocity with the preset process linear velocity, it can identify in real time whether the fiber is in an excessively fast stretching or excessively slow relaxation state, thereby quantifying the kinetic energy interference intensity and providing a quantitative velocity deviation reference for tension feedforward compensation.

[0019] According to the present invention, a dynamic compensation control method for winding tension of composite material rods is provided. The step of obtaining the dynamic elastic modulus and equivalent viscosity coefficient of the prepreg at each moment includes: monitoring the heater output through a thermal control system to obtain the heating temperature of the prepreg at each moment; and obtaining the dynamic elastic modulus and equivalent viscosity coefficient of the prepreg at each moment by consulting a preset material property database mapping table and interpolating based on the heating temperature of the prepreg at each moment.

[0020] According to the present invention, a dynamic compensation control method for the winding tension of composite material rods is provided. The method for obtaining the phase correction factor at each moment includes: dividing the product of the dynamic elastic modulus at each moment and the sampling period of the control system by the equivalent viscosity coefficient to obtain an intermediate ratio, and using the negative exponential function value of the intermediate ratio as the phase correction factor.

[0021] The application establishes a phase correction factor calculation method based on material relaxation frequency characteristics, associates dynamic elastic modulus, equivalent viscous coefficient and sampling period by using a negative exponential function relationship, can accurately represent the viscoelastic response lag degree of the prepreg tape after being heated, and identifies the strength of the material memory effect, thereby effectively avoiding the system resonance caused by the lag of the compensation action to the physical demand.

[0022] According to the composite rod winding tension dynamic compensation control method provided by the application, the instantaneous linear speed fluctuation and the phase correction factor at each moment are used to obtain a dynamic compensation torque instruction, which comprises the following steps:

[0023] ;

[0024] 、 、 are the dynamic compensation torque instructions, the instantaneous linear speed fluctuation and the phase correction factor at the first moment, respectively, is a system torque conversion coefficient.

[0025] The application combines the instantaneous linear speed fluctuation and the phase correction factor organically by using a specific torque compensation algorithm, not only generates a basic compensation according to the speed fluctuation, but also adjusts the compensation strength by using a dynamic gain term constructed by the phase factor; when the material viscosity is large and the lag is strong, the algorithm automatically enhances the compensation strength to offset the internal damping consumption, realizes the double reconstruction of the torque amplitude and phase, and ensures that the electromagnetic torque output by the motor can accurately offset the tension peak value caused by the geometric mutation of the square tube corner.

[0026] According to the composite rod winding tension dynamic compensation control method provided by the application, the dynamic compensation torque instruction is output to the tension unwinding motor to realize the adjustment of the winding tension, which comprises the following steps: subtracting the dynamic compensation torque instruction from the static torque instruction for maintaining the reference tension to generate a target instruction; the motion controller sends the target instruction to the servo driver; the servo driver controls the phase current amplitude of the unwinding motor according to the torque mode to generate an electromagnetic torque corresponding to the target instruction, thereby realizing the adjustment of the winding tension.

[0027] According to the composite rod winding tension dynamic compensation control method provided by the application, the dynamic compensation torque instruction is output to the tension unwinding motor to realize the adjustment of the winding tension, which further comprises the following steps: using an online tension sensor to monitor the actual tension of the prepreg tape at each moment in real time; comparing the actual tension with the set target constant tension to obtain a tension deviation; adjusting the tension deviation by a PID controller and superimposing the adjustment amount to the compensation torque instruction.

[0028] In the second aspect, the present application provides a composite rod winding tension dynamic compensation control system, which adopts the following technical scheme:

[0029] A composite rod winding tension dynamic compensation control system, comprising a processor and a memory, wherein the memory stores computer program instructions, and the computer program instructions are executed by the processor to implement the above-mentioned composite rod winding tension dynamic compensation control method.

[0030] By adopting the above technical scheme, the above-mentioned composite rod winding tension dynamic compensation control method is generated into a computer program and stored in the memory to be loaded and executed by the processor, so that a terminal device is manufactured according to the memory and the processor, and the use is facilitated.

[0031] The present application has the following technical effects:

[0032] Based on the above technical scheme, the present application provides a composite rod winding tension dynamic compensation control method and system, which acquires the motion state and geometric parameters of the rotating mandrel in real time, calculates the instantaneous linear velocity fluctuation caused by the change of the non-circular cross-section contour, and introduces a phase correction factor in combination with the dynamic elastic modulus and equivalent viscous coefficient of the prepreg, so as to solve the problem of phase shift caused by the fact that the traditional pure geometric control algorithm does not consider the thermal state properties of the material. In addition, the present application combines the linear velocity fluctuation obtained by kinematic analysis with the material hysteresis obtained by dynamic correction to generate a dynamic compensation torque instruction, realizes the accurate coincidence of the compensation signal and the actual physical demand on the time axis, effectively suppresses the tension shock in the winding process of the square tube and other non-circular members, effectively reduces the possibility of fiber relaxation or bruising, and thus effectively improves the product quality. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A flowchart of a composite rod winding tension dynamic compensation control method provided by the embodiment of the present application is shown in the figure;

[0034] Figure 2 A running curve diagram of the instantaneous linear velocity fluctuation in the rotating process of the square tube provided by the embodiment of the present application is shown in the figure;

[0035] Figure 3 A comparison diagram of the present application and the prior art winding tension stability is shown in the figure.

[0036] Figure 4 A comparison diagram of the present application and the prior art winding tension stability is shown in the figure. DETAILED DESCRIPTION

[0037] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application.

[0038] The embodiment of the present application discloses a composite material rod winding tension dynamic compensation control method, please refer to Figure 1 Figure 1 The embodiment of the present application provides a flow chart in the composite material rod winding tension dynamic compensation control method, and the method specifically includes the following steps:

[0039] S1: obtaining the rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotational angle.

[0040] It should be noted that the initialization and real-time acquisition of the winding process parameters are the physical logic starting point of the entire compensation algorithm. The polar radius is the distance from the geometric center of the square tube mandrel to the boundary. During the rotating winding process, the distance from the geometric center of the square tube mandrel to the boundary changes with the angle, resulting in that the winding geometric relationship is not constant, and the linear speed of the fiber contact point presents periodic fluctuation.

[0041] Due to the great difference between the polar radius of the corner and the plane of the square tube, such geometric unevenness is the reason for the fluctuation of the winding speed. If the system cannot obtain accurate mandrel geometric parameters or real-time rotational angle, the correct linear speed deviation cannot be calculated, and the feedforward compensation amount will be completely invalid. In addition, the movement speed of the nozzle determines the fiber laying track. If this parameter is ignored, the calculation of the resultant linear speed will be deviated. The calculation distortion caused by the lack of real-time working condition data will directly lead to the loss of control of the winding tension.

[0042] Based on this, the embodiment of the present application can obtain the rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotational angle, so as to realize the tension compensation of the square tube mandrel in the rotating winding process.

[0043] Among them, the data acquisition frequency can be set to 10kHz, and the corresponding sampling period is 0.1ms, which can be set according to actual needs.

[0044] For example, in the embodiment of the present application, the rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotational angle are obtained, including: obtaining the geometric parameters of the mandrel through the man-machine interaction interface, including the side length and the chamfer radius; obtaining the rotational angle and the rotational angular velocity of the mandrel through the spindle encoder; obtaining the horizontal movement of the nozzle through the displacement sensor, and calculating the axial movement speed. ​

[0045] wherein the rotation angle of the main shaft is used to determine the current geometric position of the cross section, and the rotation angular velocity is used to determine the instantaneous change of the linear velocity.

[0046] For example, in the embodiment of the present application, the acquisition method of the real-time polar radius of the fiber contact point to the rotation center of the mandrel under the rotation angle comprises:

[0047]

[0048] is the real-time polar radius at the moment of t, is the side length of the mandrel, is the rotation angle of the mandrel at the moment of t, is the cosine function. is the angle modulo operation value of the rotation angle, that is, is the angle value after the modulo operation. Wherein the real-time polar radius is used to represent the dynamic distance of the fiber contact point to the central axis. In the relationship, ensures that the calculation of the real-time polar radius can change periodically with the four faces of the pipe. When the rotation angle of the mandrel is a multiple of 45 degrees, it points to the corner, at this time tends to 0, and the cosine function value reaches the maximum value 1, resulting in the real-time polar radius

[0049] reaches the minimum value , which indicates that at this angle, the force arm of the fiber being stretched is the longest, and if the speed is not adjusted, the tension will rise sharply due to the rapid expansion of the polar radius. For example: when the side length of the mandrel is 100 mm, the real-time polar radius 70.7 mm can be calculated when the rotation angle of the mandrel is 45 degrees. In this way, the embodiment of the present application can establish a dynamic model of the winding track through real-time sensing of the motion state and geometric size of the rotating mandrel, and provide a data basis for evaluating the linear velocity fluctuation.

[0050] S2: Calculate the instantaneous linear velocity fluctuation caused by the change of the non-circular cross section profile of the mandrel at each moment. The instantaneous linear velocity fluctuation is positively correlated with the rotation angular velocity, the real-time polar radius, and the axial movement speed.

[0051]

[0052] S2: Calculate the instantaneous linear velocity fluctuation caused by the change of the non-circular cross section profile of the mandrel at each moment. The instantaneous linear velocity fluctuation is positively correlated with the rotation angular velocity, the real-time polar radius, and the axial movement speed.

[0053] ​​​It's important to note that the non-circular cross-section of the square tube is the physical source of tension fluctuations. The core challenge of non-circular winding lies in the constant rotational speed but non-constant linear velocity. When the square tube rotates, even if the motor's angular velocity remains constant, the instantaneous linear velocity of the pulled fiber will fluctuate periodically, like a pulse, due to the real-time switching between the corner and straight sections. Without calculating this pulsation, the control system cannot identify whether the fiber is currently in a state of excessive stretching or excessive relaxation. Without assessing such changes, the tension system can only passively adjust based on the delayed feedback from the tension sensor. Because the winding speed is extremely fast, this passive adjustment often lags behind physical changes, causing the fiber to break at the corners or wrinkle on the flat surfaces.

[0054] Based on this, embodiments of the present invention can obtain the deviation of the synthesized linear velocity from the process target linear velocity by synthesizing the rotational tangential velocity and the axial movement velocity, and can accurately locate the peaks and troughs of the velocity fluctuations.

[0055] Furthermore, in a horizontal winding machine, the fiber contact point simultaneously participates in two mutually perpendicular movements: the tangential velocity driven by the rotation of the mandrel and the axial velocity generated by the movement of the threading carriage along the axis of the rod. Since the two directions of motion are perpendicular in physical space, based on the Pythagorean theorem, the fiber contact point needs to be calculated by taking the square root of the square root. This ensures that the compensation amount is based on the real-time adjustment of the tension motor output according to the speed change of the fiber in three-dimensional space, thereby eliminating dynamic errors caused by cross-sectional geometric features.

[0056] For example, in an embodiment of the present invention, calculating the instantaneous linear velocity pulsation caused by the change in the non-circular cross-sectional profile of the mandrel at each moment includes:

[0057] ;

[0058] For the first The instantaneous linear velocity pulsation at time t. For the first angular velocity of rotation at time t, For the first Real-time polar radius at time t, For the first The axial movement speed of the threaded nozzle at all times. This is the preset linear velocity.

[0059] The preset linear velocity is the target constant linear velocity preset by the process, which serves as a reference. Optionally, it can be set to 0.5 m / s, and the specific setting can be made according to actual needs.

[0060] In this relationship, the instantaneous linear velocity pulsation at each moment is used to characterize the degree to which the actual winding linear velocity deviates from the process setting value.

[0061] is the tangential velocity term generated by rotation. Since or is larger, the fiber sweeps a longer arc length in unit time, resulting in a higher instantaneous synthetic speed, and thus the generated instantaneous linear velocity fluctuation increases, showing a positive correlation. Similarly, the increase of the axial movement speed of the nozzle also increases the length of the synthetic vector, which increases the instantaneous linear velocity fluctuation, showing a positive correlation. is the actual linear velocity, which is calculated by and The difference between the two can obtain the linear velocity decrement or increment required to offset the speed disturbance caused by such geometric reasons by the unwinding motor.

[0062] For example: the side length of the mandrel is 100 mm, the target constant linear velocity is 0.5 m / s, and when the rotation angle of the mandrel is 45 degrees, the real-time polar radius is 70.7 mm. If the angular velocity of the spindle is 10 rad / s and the axial movement speed is 0.1 m / s, substitute into the relationship formula to calculate 0.214 m / s. This positive fluctuation indicates that the tension will soon produce a sharp positive peak.

[0063] When the calculated instantaneous linear velocity fluctuation is negative, it means that the current instantaneous synthetic linear velocity is lower than the preset linear velocity, and the generated dynamic compensation torque is negative at this time. The system will increase the braking torque on the basis of the static torque to prevent the fiber from relaxing.

[0064] Please refer to Figure 2 , as shown, Figure 2 is a kind of instantaneous linear velocity fluctuation running curve schematic diagram in square tube rotation process provided by the embodiment of the application, wherein the horizontal axis is the rotation angle of the square tube mandrel, and the vertical axis is the periodic amplitude.

[0065] The instantaneous linear velocity fluctuation is not a horizontal straight line, but presents a obvious periodic upward convex peak at the four corner positions of the square tube, which intuitively reflects that the non-circular cross section causes the polar radius to suddenly change, thereby generating a speed fluctuation, which is the root cause of tension fluctuation.

[0066] According to the above steps, the real-time extraction of the instantaneous linear velocity fluctuation at each moment can be realized, the kinetic energy interference intensity caused by the non-circular cross section can be evaluated, and quantitative instruction reference for tension feedforward compensation can be effectively provided.

[0067] S3: Obtain the dynamic elastic modulus and equivalent viscous coefficient of the prepreg at each moment, calculate the phase correction factor for representing the viscoelastic response hysteresis of the prepreg at each moment according to the dynamic elastic modulus and the equivalent viscous coefficient, the phase correction factor is negatively correlated with the dynamic elastic modulus and positively correlated with the equivalent viscous coefficient.

[0068] It should be noted that the prepreg has significant viscoelasticity after being heated. The traditional wire winding can be regarded as rigid connection, but the resin carbon fiber after being heated is similar to a spring with damping. When the unwinding motor makes a compensation action, the change of tension will not be transmitted to the contact point instantaneously, but there is a phase lag caused by the internal friction of the material and the movement of molecular chains. If the viscoelastic response lag of the prepreg is not analyzed, the compensation instruction will be misaligned with the physical demand on the time axis. For example, when the system detects that the tension needs to be reduced, the compensation instruction is issued, but due to the viscosity lag of the material, when the instruction takes effect, the contact point may have passed the corner and entered the flat section, at this time, the compensation actually aggravates the instability of the tension.

[0069] Based on this, the embodiment of the present application can introduce a phase correction factor in dry winding, evaluate the viscosity degree of the material at the current temperature, and adjust the timing of issuing the compensation instruction, so as to realize the coincidence of the compensation phase and the physical fluctuation.

[0070] Further, in dry winding, the prepreg becomes soft after passing through the heater, and its mechanical behavior is no longer an ideal rigid body. When the temperature rises, the activity of the internal molecular chain segments of the material increases, resulting in a decrease in dynamic elastic modulus and a relatively increased influence of the equivalent viscosity coefficient. According to the Maxwell viscoelastic theory, there is a lag in the establishment of stress.

[0071] For example, in the embodiment of the present application, the dynamic elastic modulus and the equivalent viscosity coefficient of the prepreg at each moment are obtained, including: monitoring the output of the heater through the thermal control system to obtain the heating temperature of the prepreg at each moment; based on the heating temperature of the prepreg at each moment, consulting a preset material property database mapping table and performing interpolation to obtain the dynamic elastic modulus and the equivalent viscosity coefficient of the prepreg at each moment.

[0072] The preset material property database mapping table can be obtained by experiments to obtain the mechanical parameters of the prepreg under different thermal states. Since part of the collected heating temperatures do not have corresponding temperatures in the material property data, they can be processed by difference.

[0073] For example, when the temperature feedback by the thermal control system is 82.5°C, and only the data of 80°C and 85°C are stored in the database, the controller can calculate the dynamic elastic modulus and the equivalent viscosity coefficient at the accurate temperature by using the linear interpolation method.

[0074] For example, in the embodiment of the present application, the phase correction factor at each moment is obtained in the following manner: the product of the dynamic elastic modulus at each moment and the sampling period of the control system is divided by the equivalent viscosity coefficient to obtain an intermediate ratio, and the negative exponential function value of the intermediate ratio is taken as the phase correction factor.

[0075] For the convenience of understanding, the embodiment of the present application provides a specific relationship of the phase correction factor as follows:

[0076] ;

[0077] is the phase correction factor at the time of the first , is the dynamic elastic modulus at the time of the first , is the sampling period of the control system, is the equivalent viscous coefficient at the time of the first , is the exponential function with as the base.

[0078] Among them, the dynamic elastic modulus is used to represent the rigidity degree of the material, and the equivalent viscous coefficient is used to represent the flow resistance of the material after being heated.

[0079] In the above relationship, constitutes the relaxation frequency characteristics of the material. Since the larger the dynamic elastic modulus is, the closer the material is to a rigid spring, the stronger the energy storage ability is, and the response is extremely fast, it will cause the phase correction factor to decrease in the negative exponential power, and tend to the characteristic value of the response without loss, so it is negatively correlated. The larger the equivalent viscous coefficient is, the larger the internal damping of the material is, the more energy is dissipated, and the more serious the response lag is, which will cause the value of the exponential term to decrease, thereby increasing the overall value of the phase correction factor, and showing a positive correlation.

[0080] Through the phase correction factor, the system can identify that the more viscous the material is, the more it needs to intervene in advance to overcompensate. If the phase correction factor is small, it means that the material has strong memory effect and physical response lag is serious. If the time point of issuing the instruction is not adjusted according to the phase correction factor, the compensation signal will arrive later than the physical demand, not only cannot eliminate the fluctuation, but also may cause system resonance, resulting in the decrease of the interlaminar shear strength of the product.

[0081] For example: the system period is 0.001s. When the heating temperature is 80℃, the dynamic elastic modulus obtained by looking up the table is Pa, the equivalent viscous coefficient is Pa·s, and the intermediate ratio calculated is is , and the corresponding is . If the temperature rises to 100℃, the material becomes soft, decreases to Pa, and the calculated is . As can be seen, with the change of temperature and material state, the phase correction factor will also be dynamically adjusted to represent different response lag degrees.

[0082] Based on the phase correction factor obtained at each moment through the above steps, the phase shift caused by the thermal viscoelasticity of the material is evaluated, which can effectively improve the problem of asynchronous control commands and physical responses.

[0083] S4: Based on the instantaneous linear velocity pulsation and phase correction factor at each moment, a dynamic compensation torque command is obtained. The dynamic compensation torque command is negatively correlated with the phase correction factor. The dynamic compensation torque command is output to the tension unwinding motor to adjust the winding tension.

[0084] It should be noted that the instantaneous linear velocity pulsation obtained in the above steps is an external excitation source determined by the geometric characteristics of the square tube cross-section. This assesses the instantaneous kinetic energy fluctuation caused by the abrupt change in the mandrel's polar diameter with the rotation angle, providing a baseline input for the compensation strength of the tension unwinding motor. The phase correction factor assesses the degree to which the prepreg tape behaves as a viscoelastic body after heating in dry winding, providing geometric feedforward for the compensation strength of the tension unwinding motor and determining the time difference for issuing commands in advance. In non-circular winding, relying solely on PID control for closed-loop operation is slow, but directly relying on geometric feedforward may be too simplistic. Without combining the phase factor for gain adjustment, when the material becomes very viscous due to high temperatures, ordinary torque compensation will be completely consumed by the viscous damping within the material, leading to a reduction in compensation effectiveness.

[0085] Based on this, the embodiments of the present invention combine the instantaneous linear velocity pulsation with the phase correction factor, and combine the material properties to achieve early sensing. Finally, the dynamic compensation torque command can be calculated to convert the linear velocity pulsation obtained based on kinematic analysis and the material hysteresis obtained based on dynamic correction into a current signal that the motor can directly execute.

[0086] Furthermore, during the winding process of the square tube, the unwinding motor is typically in a regenerative braking state to provide basic tension. When the fiber moves to the corner of the mandrel, the instantaneous linear velocity pulsation increases, causing the fiber to be subjected to severe instantaneous stretching. Based on this, embodiments of the present invention actively reduce the motor's braking resistance by calculating a positive dynamic compensation torque command and subtracting it from the static torque command that maintains the reference tension. Without this reverse cancellation, relying solely on the hysteresis adjustment of the PID closed loop, the motor will be unable to respond promptly to sudden changes in linear velocity, causing the fiber to be thinned or even break at the corner.

[0087] For example, in an embodiment of the present invention, a dynamic compensation torque command is obtained based on the instantaneous linear velocity pulsation and phase correction factor at each moment, as shown in the following formula:

[0088] ;

[0089] For the first Dynamic compensation torque instruction of the moment, System torque conversion coefficient, First phase correction factor of the moment, Instantaneous linear velocity fluctuation of the moment, Second phase correction factor of the moment, Phase correction factor of the moment.

[0090] The unit of the dynamic compensation torque instruction is .

[0091] The system torque conversion coefficient is used to convert the speed difference into torque, and can be obtained according to the real-time winding diameter of the unwinding reel, the transmission ratio of the speed reducer, the torque constant of the motor, and the mechanical transmission efficiency. The value will be adjusted downward as the winding diameter becomes smaller. Optionally, in the embodiment of the application, the value range of the system torque conversion coefficient can be set to 0.2 to 0.5.

[0092] In the above relationship, is a basic term. When the square tube rotates to the corner, the instantaneous linear velocity fluctuation increases, and the dynamic compensation torque instruction increases synchronously. In this way, the resistance torque of the unwinding motor can be increased to offset the tension relaxation tendency. Since the greater the instantaneous linear velocity fluctuation, the greater the speed inertia that needs to be offset, the dynamic compensation torque instruction increases accordingly, and they are positively correlated. When the value is negative, it represents that the linear velocity is lower than the preset linear velocity. At this time, the compensation torque direction is opposite to the positive value, that is, the compensation torque is reversed, so as to increase the tension.

[0093] is a dynamic gain term. The high-viscosity material itself has a filtering effect. Excessive compensation will cause oscillation. The smaller the phase correction factor, the better the material elastic response and the smaller the lag. At this time, the value of is relatively large, and the system will output a sufficient torque to match this sensitive response. If the phase correction factor increases, it means that the material has strong viscosity and slow response. Based on this, the embodiment of the application can adjust the compensation strength by reducing , and cooperate with the phase lead angle algorithm built in the control system to realize accurate reconstruction of the torque amplitude and phase, so that the dynamic compensation torque instruction and the phase correction factor present a negative correlation.

[0094] For example, the system torque conversion coefficient is 0.25. If the fiber moves to the corner of the square tube at the current moment, the corresponding instantaneous linear velocity fluctuation at this time is 0.2 m / s.

[0095] In the case of high heating temperature and significant softening of the prepreg, the material has strong hysteresis effect. At this time, the phase correction factor is low, and the value is , and the obtained dynamic compensation torque instruction is .

[0096] In the case of moderate heating temperature, the material hysteresis effect is weak, the pre-impregnated tape keeps a certain rigidity, the phase correction factor is higher, and the value is The obtained dynamic compensation torque instruction is .

[0097] As can be seen, when the material viscous loss increases, the dynamic compensation torque instruction of the system also increases the compensation strength.

[0098] Please refer to Figure 3 and Figure 4 , Figure 3 A prior art provided for an embodiment of the present application and a tension response phase alignment comparison diagram. As can be seen from the figure, the wave peak of the prior art deviates from the physical peak of the tension fluctuation, and there is a significant phase right shift lag; the wave peak of the present application is basically consistent with the trend of the physical fluctuation through the adjustment of the phase correction factor. Therefore, the present scheme can offset the molecular chain movement delay of the pre-impregnated tape after being softened by heat, Figure 3 which can illustrate the effect of the present application in dealing with the response lag caused by material viscoelasticity.

[0099] Figure 4 A present application and prior art winding tension stability actual measurement comparison diagram provided for an embodiment of the present application. As can be seen from the figure, the prior art produces severe up and down oscillation when passing through the square tube corner, the fluctuation amplitude is huge and accompanied by overshoot phenomenon; the present application is extremely smooth and always closely adheres to the target reference line. Figure 4 which can illustrate that through the real-time intervention of the dynamic compensation torque instruction, the system can effectively suppress the tension fluctuation caused by speed pulsation and material lag, and ensure the high tightness and quality stability of the winding product.

[0100] After obtaining the dynamic compensation torque instruction at each time according to the above steps, the controller issues the dynamic compensation torque instruction in advance to the servo driver, controls the motor to generate a corresponding electromagnetic torque, so as to offset the tension mutation caused by the square tube corner.

[0101] For example, in an embodiment of the present application, the dynamic compensation torque instruction is output to the tension unwinding motor to realize the adjustment of the winding tension, including: subtracting the dynamic compensation torque instruction from the static torque instruction for maintaining the reference tension to generate a target instruction; the motion controller sends the target instruction to the servo driver; the servo driver controls the phase current amplitude of the unwinding motor according to the torque mode to generate an electromagnetic torque corresponding to the target instruction, so as to realize the adjustment of the winding tension.

[0102] Wherein, according to the motor torque constant, the motor generates the electromagnetic torque corresponding to the dynamic compensation torque instruction, and directly acts on the unwinding shaft to adjust the fiber tension. When the main shaft rotates to the angle at which the corner will cause a sharp increase in tension, the motor generates an opposite torque in advance to realize the physical level of hysteresis offset.

[0103] Further, in order to maintain the stability of the tension in the high-speed winding state, the actual tension value can be fed back in real time by the online tension sensor during the execution process, and the residual deviation can be fine-tuned by the PID algorithm.

[0104] For example, in the embodiment of the application, the dynamic compensation torque instruction is output to the tension unwinding motor to realize the adjustment of the winding tension, which further comprises: using an online tension sensor to monitor the actual tension of the prepreg tape at each moment in real time; comparing the actual tension with the set target constant tension to obtain a tension deviation; adjusting the tension deviation through a PID controller and superimposing the adjustment amount on the compensation torque instruction.

[0105] Wherein, the step of adjusting the tension deviation through the PID controller and superimposing the adjustment amount on the compensation torque instruction can be realized by the prior art, and the embodiment of the application will not be repeated here.

[0106] It can be seen that in the embodiment of the application, when the composite rod winding tension dynamic compensation control is implemented, the rotational angular velocity of the rotating mandrel, the axial movement speed of the filament nozzle, and the real-time polar radius of the fiber contact point to the center of the rotating mandrel under the rotating angle can be obtained; the instantaneous linear velocity fluctuation caused by the change of the non-circular cross-section profile of the mandrel at each moment is calculated, and the instantaneous linear velocity fluctuation is positively correlated with the rotational angular velocity, the real-time polar radius and the axial movement speed; the dynamic elastic modulus and the equivalent viscous coefficient of the prepreg tape at each moment are obtained, and the phase correction factor for characterizing the viscoelastic response hysteresis of the prepreg tape at each moment is calculated according to the dynamic elastic modulus and the equivalent viscous coefficient, the phase correction factor is negatively correlated with the dynamic elastic modulus and positively correlated with the equivalent viscous coefficient; based on the instantaneous linear velocity fluctuation and the phase correction factor at each moment, the dynamic compensation torque instruction is obtained, and the dynamic compensation torque instruction is negatively correlated with the phase correction factor; the dynamic compensation torque instruction is output to the tension unwinding motor to realize the adjustment of the winding tension, which effectively improves the accuracy of the tension dynamic compensation control, thereby effectively improving the quality of the product.

[0107] The embodiment of the application also discloses a composite rod winding tension dynamic compensation control system, comprising a processor and a memory, and the memory stores computer program instructions, which realize the composite rod winding tension dynamic compensation control method provided by the application when the computer program instructions are executed by the processor.

[0108] The system also includes other components known to those skilled in the art such as a communication bus and a communication interface, etc., the arrangement and functions of which are known in the art and thus are not described here in detail.

[0109] In the present application, the aforementioned memory can be any tangible medium that contains or stores a program which can be used by or in connection with an instruction execution system, apparatus, or device.

[0110] The above are preferred embodiments of the present application, not to limit the protection scope of the present application, therefore: all equivalent changes made in the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A composite rod winding tension dynamic compensation control method, characterized in that, The method comprises the following steps: acquiring the rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle, and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotation angle; calculating the instantaneous linear speed fluctuation caused by the change of the non-circular cross-sectional profile of the mandrel at each moment, which is positively correlated with the rotational angular velocity, the real-time polar radius and the axial movement speed; the instantaneous linear speed fluctuation satisfies: ； , , , The first Instantaneous linear velocity pulsation, rotational angular velocity, real-time extreme diameter, and axial movement speed of the nozzle at any given moment. Preset linear velocity; The method for acquiring the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotation angle comprises: ； is the first time is the real-time polar radius at the moment, is the core mold side length, is the first time is the rotation angle of the core mold at the moment, is the cosine function, is the angle modulo operation value of the rotation angle; acquiring the dynamic elastic modulus and the equivalent viscous coefficient of the prepreg at each moment, and calculating the phase correction factor for representing the viscoelastic response hysteresis of the prepreg at each moment according to the dynamic elastic modulus and the equivalent viscous coefficient; the phase correction factor is negatively correlated with the dynamic elastic modulus and positively correlated with the equivalent viscous coefficient; the method for acquiring the phase correction factor at each moment comprises: dividing the product of the dynamic elastic modulus at each moment and the sampling period of the control system by the equivalent viscous coefficient to obtain an intermediate ratio, and taking the negative exponential function value of the intermediate ratio as the phase correction factor; based on the instantaneous linear speed fluctuation and the phase correction factor at each moment, obtaining a dynamic compensation torque instruction, which is negatively correlated with the phase correction factor; the dynamic compensation torque instruction satisfies: ； , , are the dynamic compensation torque command, the instantaneous linear speed ripple amount, and the phase correction factor at the time point of the first , is the system torque conversion coefficient; outputting the dynamic compensation torque instruction to the tension unwinding motor to adjust the winding tension.

2. The composite rod winding tension dynamic compensation control method according to claim 1, characterized in that, The method for acquiring the rotational angular velocity of the rotating mandrel, the axial movement speed of the nozzle, and the real-time polar radius of the fiber contact point to the rotating center of the mandrel under the rotation angle comprises: acquiring the geometric parameters of the mandrel, including the side length and the chamfer radius, through a human-computer interaction interface; acquiring the rotation angle and the rotational angular velocity of the mandrel through a spindle encoder; acquiring the horizontal movement of the nozzle through a displacement sensor and calculating the axial movement speed.

3. The composite rod winding tension dynamic compensation control method according to claim 1, characterized in that, The method for acquiring the dynamic elastic modulus and the equivalent viscous coefficient of the prepreg at each moment comprises: monitoring the output of the heater through a thermal control system to acquire the heating temperature of the prepreg at each moment; based on the heating temperature of the prepreg at each moment, consulting a preset material property database mapping table and performing interpolation to obtain the dynamic elastic modulus and the equivalent viscous coefficient of the prepreg at each moment.

4. The composite rod winding tension dynamic compensation control method according to claim 1, characterized in that, The method for outputting the dynamic compensation torque instruction to the tension unwinding motor to adjust the winding tension comprises: subtracting the dynamic compensation torque instruction from the static torque instruction for maintaining the reference tension to generate a target instruction; the motion controller sends the target instruction to the servo driver; the servo driver controls the phase current amplitude of the unwinding motor according to the torque mode to generate an electromagnetic torque corresponding to the target instruction, thereby adjusting the winding tension.

5. The composite rod winding tension dynamic compensation control method according to claim 1, characterized in that, The method for outputting the dynamic compensation torque instruction to the tension unwinding motor to adjust the winding tension further comprises: using an online tension sensor to monitor the actual tension of the prepreg at each moment in real time; comparing the actual tension with the set target constant tension to obtain a tension deviation; adjusting the tension deviation through a PID controller and superimposing the adjustment amount on the compensation torque instruction.

6. A composite rod winding tension dynamic compensation control system, characterized in that, The method comprises the following steps: A processor and a memory, the memory storing computer program instructions which, when executed by the processor, implement a composite rod winding tension dynamic compensation control method according to any one of claims 1-5.

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