A twisted yarn tension self-adaptive compensation control method and system based on twist back hysteresis identification and a computer readable storage medium

Abstract

The present application relates to a kind of twist tension self-adaptive compensation control method, system and computer readable storage medium based on twist hysteresis identification.The method obtains the first twist correlation signal of twisting end and the second twist correlation signal of yarn forming end, yarn guide end or winding end, carries out synchronous pretreatment and time window matching to two kinds of signals, determines twist hysteresis amount, and determines twist decay state in combination with amplitude ratio, energy ratio, phase difference and correlation coefficient, to further determine twist transmission state.Tension compensation amount is generated according to twist transmission state, hysteresis deviation and tension fluctuation index, and the tension compensation parameter of next control cycle is updated according to the closed-loop residual error after compensation.The present application can improve the timeliness and accuracy of tension compensation, improve twist uniformity and reduce the risk of breakage.

Description

Technical Field

[0001] This invention relates to the field of textile machinery control technology, and in particular to a method, system and computer-readable storage medium for adaptive compensation control of yarn tension based on twist hysteresis identification. It is applicable to yarn twisting equipment to identify the twist transmission state between the twisting end and the yarn forming end, the yarn guiding end or the winding end during the twisting process, and to perform adaptive compensation control of yarn tension based on the identification results. Background Technology

[0002] Twisting is a crucial process in textile production. It typically involves using a twisting mechanism to twist multiple single yarns, filaments, or yarn components together, causing them to bind together and improving the yarn's strength, abrasion resistance, dimensional stability, and subsequent weaving or processing properties. During twisting, the yarn usually passes through stages such as yarn feeding, twisting, guiding, tension adjustment, and winding. The motion, tension, and twist transmission at each stage collectively affect the final yarn quality.

[0003] In actual production, the quality of twisted yarn is closely related to factors such as spindle speed, yarn feed speed, winding speed, yarn tension, air loop condition, yarn guide path, and the yarn's own elasticity, frictional characteristics, and torsional transmission characteristics. Among these, tension variation has a significant impact on twist transmission and yarn stability. When the yarn tension is too high, the yarn is prone to excessive elongation, wear, or even breakage; when the yarn tension is too low, the yarn's running stability decreases, easily leading to problems such as air loop fluctuations, poor winding formation, or uneven twist. Therefore, stable tension control during the twisting process is an important means to improve twisted yarn quality and production efficiency.

[0004] Existing yarn twisting equipment typically includes a yarn feeding mechanism, a twisting mechanism, a tension control mechanism, and a winding mechanism. The yarn feeding mechanism delivers yarn to the twisting area, the twisting mechanism applies twist to the yarn, the tension control mechanism adjusts the tension of the yarn during its movement, and the winding mechanism winds the twisted yarn into shape. To monitor the equipment's operating status, some yarn twisting equipment is also equipped with detection components such as tension sensors, spindle speed detectors, winding speed detectors, yarn breakage detectors, or air ring detectors, and adjustments are made to the tension control mechanism, spindle speed control mechanism, yarn feeding mechanism, or winding mechanism based on the detection results.

[0005] In existing control methods, the most common approaches are open-loop control based on preset process parameters or closed-loop control based on tension signals from a single detection location. For example, the equipment can operate based on set spindle speed, yarn feed speed, winding speed, and target tension value; when the tension value at a certain location deviates from the target range, the output of the tension actuator is adjusted to reduce tension fluctuations. This type of method can improve yarn running stability to some extent, but its control basis is usually concentrated on local tension, spindle speed, or winding speed, making it difficult to fully reflect the dynamic changes in twist transmission from the twisting end to the yarn forming end, yarn guiding end, or winding end.

[0006] Because yarn possesses certain elasticity, torsional transmission characteristics, and frictional properties, the twist generated at the twisting end is not always immediately, completely, and stably transmitted to subsequent yarn segments. During transmission, the twist may be affected by factors such as yarn material, tension level, running speed, guide friction, airflow fluctuations, and winding state, resulting in phenomena such as response delay, amplitude attenuation, phase deviation, or reduced correlation. In other words, there may be a lag and attenuation between the input state at the twisting end and the actual response state at the yarn forming end, guide end, or winding end.

[0007] When there is a lag or attenuation in twist transmission, even if the spindle speed or twisting state at the twisting end remains relatively stable, the actual twist response at the yarn forming end, yarn guiding end, or winding end may still be delayed, fluctuating, or insufficient. In this case, if control is still based solely on single-point tension signals, fixed process parameters, or local speed signals, problems such as delayed compensation timing, inaccurate compensation direction, or mismatched compensation amplitude are likely to occur, leading to uneven twist, increased tension fluctuations, unstable winding formation, increased breakage rate, and decreased yarn consistency among multiple spindles.

[0008] Furthermore, when changing yarn types or batches, increasing or decreasing speed, starting or stopping the machine, or when the external environment changes, the elasticity, frictional properties, and torsional transmission characteristics of the yarn may change, and the twist transmission state may also change dynamically accordingly. Existing control methods usually rely on preset parameters, experience-based adjustments, or single-point feedback control, which makes it difficult to identify in a timely manner the hysteresis and attenuation changes between the input state at the twisting end and the response state of the subsequent yarn segment. It is also difficult to coordinate the tension actuator, yarn feeding mechanism, winding mechanism, or spindle speed control mechanism according to different twist transmission states.

[0009] Therefore, existing twist tension control technologies still have shortcomings in identifying the dynamic process of twist transmission, improving the timeliness of tension compensation, improving twist uniformity, reducing the risk of yarn breakage, and shortening the process stabilization time. There is an urgent need for a control scheme that can reflect the twist correlation state between the twisting end and the yarn forming end, the yarn guiding end, or the winding end, in order to identify the hysteresis and attenuation characteristics in the twist transmission process and accordingly perform adaptive compensation control of the twist tension. Summary of the Invention

[0010] In view of this, the purpose of this invention is to provide a twist tension adaptive compensation control method, system, and computer-readable storage medium based on twist hysteresis identification, in order to solve the problems of existing twisting equipment that mainly rely on single-point tension signals, local speed signals, or fixed process parameters for control, which makes it difficult to timely identify the hysteresis, attenuation, and phase mismatch in the transmission of twist from the twisting end to the yarn forming end, yarn guiding end, or winding end. This results in untimely tension compensation, inaccurate compensation direction, and mismatched compensation amplitude, which in turn causes uneven twist, aggravated tension fluctuations, unstable winding formation, increased breakage rate, and decreased consistency of multi-spindle yarn formation.

[0011] To achieve the above objectives, the present invention provides the following technical solution: In one embodiment of the present invention, an adaptive compensation control method for twist tension based on twist hysteresis identification is provided, applied to a twisting device having a twisting mechanism, a tension execution mechanism, a yarn feeding mechanism, and a winding mechanism, comprising the following steps: acquiring a first twist correlation signal at the twisting end, the first twist correlation signal being used to characterize the input rhythm, input intensity, or input fluctuation state of the twisting mechanism applying twist to the yarn; acquiring a second twist correlation signal at the yarn forming end, the yarn guiding end, or the winding end, the second twist correlation signal being used to characterize the response rhythm, response intensity, or response fluctuation state of the twist after it is transmitted through the yarn; performing synchronous preprocessing on the first twist correlation signal and the second twist correlation signal within the same control cycle; and performing time-based processing on the synchronously preprocessed first twist correlation signal and the second twist correlation signal within a preset sliding time window. The system performs window matching to determine the response delay between the two signals and uses this response delay as the twist hysteresis. It then determines the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first and second twist-related signals. Based on the twist hysteresis and the twist attenuation state, it determines the twist transmission state of the current twisting station. Based on the twist transmission state, the hysteresis deviation of the twist hysteresis relative to the target hysteresis, and the tension fluctuation index, it determines the adjustment direction and amplitude of the tension compensation amount and outputs the tension compensation amount to the tension actuator. After tension compensation, it acquires the second twist-related signal again, calculates the closed-loop residual between the compensated actual tension fluctuation value and the target tension fluctuation value, and updates the tension compensation parameters for the next control cycle based on the closed-loop residual.

[0012] Furthermore, the first twist-related signal includes at least one of the following: spindle speed pulse signal, twisting disc rotation speed signal, yarn rotation photoelectric pulse signal at the twisting end, and tension signal at the twisting end; the second twist-related signal includes at least one of the following: winding end tension signal, yarn guide end tension signal, yarn vibration signal, air ring radius change signal, winding speed signal, and yarn twist detection signal.

[0013] Preferably, the synchronization preprocessing includes timestamp synchronization, outlier removal, filtering, and amplitude normalization; wherein, the timestamp synchronization is used to eliminate the data acquisition time base deviation between the detection position at the twisting end and the detection positions at the yarn forming end, yarn guiding end, or winding end; and the amplitude normalization is used to make the first twist-related signal and the second twist-related signal at the same signal comparison scale.

[0014] Furthermore, the twist hysteresis is determined as follows: multiple candidate offset times are set within the preset sliding time window; the correlation between the first twist correlation signal and the second twist correlation signal is calculated at each candidate offset time; the candidate offset time corresponding to the maximum correlation is determined as the twist hysteresis of the current control cycle; when the maximum correlation is lower than the preset confidence threshold, the preset sliding time window is extended, or the twist hysteresis of the previous control cycle is used as the initial constraint value of the current control cycle.

[0015] Preferably, the twist attenuation state is determined by constructing a twist transmission state vector, which includes twist hysteresis, twist attenuation coefficient, phase deviation, signal correlation coefficient, and tension fluctuation index. The twist attenuation coefficient is determined based on the ratio of the change in amplitude of the second twist-related signal relative to the amplitude of the first twist-related signal, and / or based on the ratio of the change in energy of the second twist-related signal relative to the energy of the first twist-related signal. The phase deviation is determined based on the phase difference between the first twist-related signal and the second twist-related signal within the preset sliding time window; The signal correlation coefficient is determined based on the correlation between the first twist-correlation signal and the second twist-correlation signal within the preset sliding time window; The tension fluctuation index is determined based on the standard deviation, peak-to-peak value, or coefficient of variation of the tension signal within a preset time window. When the twist attenuation coefficient is lower than a preset attenuation threshold, and / or the phase deviation exceeds a preset phase threshold, and / or the signal correlation coefficient is lower than a preset correlation threshold, it is determined that there is a trend of increased twist attenuation or phase mismatch in the current control cycle.

[0016] Furthermore, the twist transmission state includes at least one of the following: normal transmission state, hysteresis increase state, twist attenuation increase state, phase mismatch state, tension instability state, and pre-breakage state; when the twist hysteresis increases for multiple consecutive control cycles and the tension fluctuation index exceeds a preset fluctuation threshold, the current twisting station is determined to be in a tension instability state; when the twist hysteresis exceeds a preset hysteresis threshold, the signal correlation coefficient is lower than a preset correlation threshold, and the second twist correlation signal shows a sudden drop or rise, the current twisting station is determined to be in a pre-breakage state.

[0017] Preferably, determining the adjustment direction and adjustment range of the tension compensation amount based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index includes: when the twist transmission state is a state of increased hysteresis, determining a first compensation component based on the product of the hysteresis deviation and a preset hysteresis compensation coefficient; when the twist transmission state is a state of increased twist attenuation, determining a second compensation component based on the product of the twist attenuation coefficient and a preset attenuation compensation coefficient; when the twist transmission state is a state of tension instability, determining a third compensation component based on the product of the tension fluctuation index and a preset tension fluctuation compensation coefficient; determining the adjustment range of the tension compensation amount based on at least one of the first compensation component, the second compensation component, and the third compensation component; and determining the adjustment direction of the tension compensation amount based on the sign of the hysteresis deviation, the deviation of the twist attenuation coefficient relative to the target attenuation coefficient, and the deviation of the tension signal relative to the target tension value.

[0018] Further, the tension compensation parameters include a hysteresis compensation coefficient, an attenuation compensation coefficient, a tension fluctuation compensation coefficient, and a speed coordination compensation coefficient; updating the tension compensation parameters for the next control cycle based on the closed-loop residual includes: maintaining the current tension compensation parameters when the closed-loop residual is less than a preset residual threshold; updating at least one of the hysteresis compensation coefficient, the attenuation compensation coefficient, the tension fluctuation compensation coefficient, and the speed coordination compensation coefficient based on the closed-loop residual when the closed-loop residual is greater than or equal to the preset residual threshold; wherein, the speed coordination compensation coefficient is used to determine the speed compensation amount or speed change slope compensation amount of the yarn feeding mechanism, the winding mechanism, or the twisting mechanism when the twist transmission state is a phase mismatch state or a twist attenuation increase state.

[0019] In one embodiment of the present invention, a twist tension adaptive compensation control system based on twist hysteresis identification is also provided, applied to a twisting device, comprising: a twisting mechanism for applying twist to yarn; a yarn feeding mechanism for feeding yarn to the twisting mechanism; a winding mechanism for winding the twisted yarn; a tension actuation mechanism for adjusting the tension of the yarn during operation; a first detection unit disposed at the twisting end for acquiring a first twist correlation signal, wherein the first twist correlation signal is used to characterize the input rhythm, input intensity, or input fluctuation state of the twisting mechanism applying twist to the yarn; and a second detection unit, wherein... A device is positioned at the yarn forming end, yarn guiding end, or winding end to acquire a second twist-related signal. This second twist-related signal characterizes the response rhythm, response intensity, or response fluctuation state after the twisted warp yarn is transmitted. A processor or controller is communicatively connected to the first detection unit, the second detection unit, the tension actuator, the yarn feeding mechanism, the winding mechanism, and the twisting mechanism, respectively. The processor or controller includes a signal synchronization processing module for performing timestamp synchronization, outlier removal, filtering, and amplitude normalization on the first twist-related signal and the second twist-related signal. The hysteresis identification module is used to perform time window matching on the first twist-related signal and the second twist-related signal after synchronous preprocessing within a preset sliding time window, determine the response delay between them, and use the response delay as the twist hysteresis; the twist attenuation analysis module is used to determine the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first twist-related signal and the second twist-related signal; the twist transmission state determination module is used to determine the twist transmission state of the current twisting station based on the twist hysteresis and the twist attenuation state; tension. The compensation control module is used to determine the adjustment direction and adjustment range of the tension compensation amount based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index; the control output module is used to output the tension compensation amount to the tension actuator, and output the speed compensation amount or speed change slope compensation amount to the yarn feeding mechanism, the winding mechanism, or the twisting mechanism according to the twist transmission state; the closed-loop update module is used to update the tension compensation parameters for the next control cycle based on the closed-loop residual between the actual tension fluctuation value after compensation and the target tension fluctuation value after tension compensation.

[0020] Alternatively, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor or controller, implements the above-described adaptive compensation control method for twist tension based on twist hysteresis identification.

[0021] Based on the above technical solution, the adaptive compensation control method, system, and computer-readable storage medium for twist tension based on twist hysteresis identification of the present invention establishes a correlation between the input state of the twisting mechanism applying twist to the yarn and the response state after the twist is transmitted through the yarn by acquiring a first twist correlation signal at the twisting end and a second twist correlation signal at the yarn forming end, yarn guiding end, or winding end. This transforms the control basis from tension detection at a single location or preset process parameters to dynamic identification of the twist transmission process. Therefore, it can reflect the response delay, attenuation changes, and correlation degree between the twisting end and subsequent yarn segments, providing a more accurate state basis for tension compensation control.

[0022] During signal processing, this invention performs timestamp synchronization, outlier removal, filtering, and amplitude normalization on the first and second twist-correlated signals within the same control cycle. This reduces the impact of acquisition time base deviation, sensor noise, mechanical vibration interference, and signal amplitude differences between different detection locations on the judgment results. The processed signals are at a comparable scale, which helps improve the reliability of time window matching, correlation calculation, and attenuation analysis.

[0023] In the process of identifying twist hysteresis, this invention sets multiple candidate offset times within a preset sliding time window, calculates the correlation between the first twist correlation signal and the second twist correlation signal at different candidate offset times, and determines the candidate offset time corresponding to the maximum correlation as the twist hysteresis. In this way, the response delay generated when the input state at the twisting end is transmitted to the yarn forming end, yarn guiding end, or winding end can be obtained online. This allows tension compensation to no longer be passively adjusted based solely on the current tension deviation, but rather to determine the compensation timing and magnitude in advance by combining the twist transmission hysteresis.

[0024] In the twist attenuation analysis process, this invention determines the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first and second twist-related signals. It then combines this with the twist hysteresis, phase deviation, signal correlation coefficient, and tension fluctuation index to determine the twist transmission state of the current twisting station. Through this comprehensive judgment, different operating states can be distinguished, such as normal transmission, increased hysteresis, increased twist attenuation, phase mismatch, tension instability, and signs of impending thread breakage. This avoids overcompensation, undercompensation, or incorrect compensation direction caused by using a single tension adjustment strategy.

[0025] During tension compensation, this invention determines the adjustment direction and amplitude of the tension compensation amount based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index, and outputs the tension compensation amount to the tension actuator. For different states such as increased hysteresis, increased twist attenuation, or tension instability, corresponding compensation components can be generated by combining the hysteresis compensation coefficient, attenuation compensation coefficient, and tension fluctuation compensation coefficient, thereby improving the targeting and accuracy of tension adjustment.

[0026] Furthermore, this invention can output speed compensation or speed change slope compensation to the yarn feeding mechanism, winding mechanism, or twisting mechanism according to the twist transmission state, so that tension adjustment is coordinated with changes in yarn feeding speed, winding speed, or spindle speed. Under operating conditions such as speed increase, speed decrease, start-up and shutdown, change of yarn type, or change of batch, this coordinated control method can reduce tension fluctuations and twist fluctuations caused by twist transmission lag, attenuation, or phase mismatch, which is beneficial to maintaining stable yarn operation.

[0027] After completing tension compensation, the present invention acquires the second twist correlation signal again and calculates the closed-loop residual between the compensated actual tension fluctuation value and the target tension fluctuation value. The tension compensation parameters for the next control cycle are then updated based on this closed-loop residual. Through closed-loop updates, the hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, and speed coordination compensation coefficient can be adjusted according to changes in yarn type, batch, operating speed, environmental conditions, and equipment status, thereby improving the adaptive capability of twist tension control.

[0028] When this invention is applied to multi-spindle twisting equipment, twist hysteresis identification, twist attenuation analysis, and tension compensation control can be performed on each twisting station separately. When a station experiences increased hysteresis, tension instability, or signs of impending yarn breakage, tension compensation, speed compensation, pre-speed reduction, tension release, alarm, or spindle stop control are only applied to that station, while other normal stations can continue to operate according to their original process parameters. This reduces the impact of abnormalities at a single station on the overall machine production and helps improve tension consistency and yarn consistency among multiple spindles.

[0029] Therefore, this invention can solve the problems of existing twisting equipment, which mainly rely on single-point tension signals, local speed signals or fixed process parameters for control, making it difficult to identify lag, attenuation and phase mismatch in the twisting process in a timely manner, resulting in untimely tension compensation, inaccurate compensation direction and mismatched compensation amplitude; at the same time, it can improve the problems caused by uneven twist, aggravated tension fluctuation, unstable winding and forming, increased breakage rate, decreased consistency of multi-spindle yarn forming and long process stabilization time. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments are briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and do not constitute a limitation on the scope of protection of the present invention. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of an adaptive compensation control system for twist tension based on twist hysteresis identification provided in an embodiment of the present invention; Figure 2 This is a flowchart illustrating an adaptive compensation control method for twist tension based on twist hysteresis identification, provided in an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached diagram: 1. Twisting mechanism; 2. Yarn feeding mechanism; 3. Winding mechanism; 4. Tension actuator; 5. First detection unit; 6. Second detection unit; 7. Signal synchronization processing module; 8. Twist hysteresis identification module; 9. Twist attenuation analysis module; 10. Twist transmission status determination module; 11. Tension compensation control module; 12. Control output module; 13. Closed-loop update module; 14. Yarn; 15. Processor or controller. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are only some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0034] In the description of this invention, the terms "first," "second," etc., are used only to distinguish different objects and are not used to limit their order, importance, or quantity. For example, the first twist-correlation signal and the second twist-correlation signal are used to represent signals acquired at different detection locations, and the use of "first" and "second" does not limit the acquisition order or signal priority.

[0035] In this embodiment of the invention, the term "twisting end" can be understood as the position where the twisting mechanism 1 applies twist to the yarn 14 or the detection area near that position; the term "yarn forming end, yarn guiding end, or winding end" can be understood as the position or area where the response state can be detected after the twist is transmitted through the yarn 14, which can be located in the yarn guiding path, the yarn forming output position, or near the winding mechanism 3. The above position division is mainly used to describe the detection source of the twist input state and the twist response state, and does not limit the specific installation form of the detection unit.

[0036] I. General Description

[0037] Combination Figure 1 and Figure 2 The adaptive compensation control method, system, and computer-readable storage medium for twist tension based on twist hysteresis identification provided in this invention are mainly used to identify the twist transmission state between the twisting end and the yarn forming end, yarn guiding end, or winding end during the twisting process, and to adaptively compensate and control the yarn tension according to the identification results. Specifically, the first twist correlation signal of the twisting end is collected by the first detection unit 5, and the second twist correlation signal of the yarn forming end, yarn guiding end, or winding end is collected by the second detection unit 6; the processor or controller 15 performs synchronous processing, twist hysteresis identification, twist attenuation analysis, and twist transmission state determination on the two types of signals, and performs compensation control on the tension actuator 4, yarn feeding mechanism 2, winding mechanism 3, or twisting mechanism 1 through the tension compensation control module 11 and the control output module 12.

[0038] Specifically, Figure 1 The system structure of an embodiment of the present invention is shown. The system may include a twisting mechanism 1, a yarn feeding mechanism 2, a winding mechanism 3, a tension actuation mechanism 4, a first detection unit 5, a second detection unit 6, and a processor or controller 15. Specifically, the yarn feeding mechanism 2 is used to feed yarn 14 into the twisting area; the twisting mechanism 1 is used to apply twist to the yarn 14; the winding mechanism 3 is used to wind the twisted yarn 14; the tension actuation mechanism 4 is used to adjust the tension of the yarn 14 during operation; the first detection unit 5 is used to acquire a first twist-related signal characterizing the twist input state at the twisting end; and the second detection unit 6 is used to acquire a second twist-related signal characterizing the response state after the twist is transmitted through the yarn 14.

[0039] The processor or controller 15 can be communicatively connected to the first detection unit 5, the second detection unit 6, the tension actuator 4, the yarn feeding mechanism 2, the winding mechanism 3, and the twisting mechanism 1. The processor or controller 15 can internally configure or run a signal synchronization processing module 7, a twist hysteresis identification module 8, a twist attenuation analysis module 9, a twist transmission state determination module 10, a tension compensation control module 11, a control output module 12, and a closed-loop update module 13. These modules can be implemented through hardware circuits, software programs, firmware programs, or combinations thereof; this invention does not impose any limitations on this.

[0040] Figure 2The control method flow of an embodiment of the present invention is illustrated. The method may include: acquiring a first twist-related signal; acquiring a second twist-related signal; performing synchronous preprocessing on the first and second twist-related signals; performing time window matching on the two types of signals within a preset sliding time window and determining the twist hysteresis; determining the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the two types of signals; determining the twist transmission state of the current twisting station based on the twist hysteresis and twist attenuation state; generating a tension compensation amount based on the twist transmission state and outputting it to the tension actuator 4; and updating the tension compensation parameters for the next control cycle based on the changes in the second twist-related signal after compensation.

[0041] The core of this invention lies in the fact that control is no longer based solely on tension signals or preset process parameters at a single location. Instead, it establishes a correlation between the twisting input state and the subsequent response state through two types of twist-related signals: the twisting end and the yarn forming end, and the yarn guiding end or the winding end. Through this correlation, the response delay, attenuation changes, and phase mismatches generated during twist transmission in the yarn 14 can be identified online, and the adjustment direction and amplitude of the tension compensation amount can be determined accordingly, thereby improving the timeliness and accuracy of tension compensation.

[0042] It should be noted that the first twist-related signal in this embodiment of the invention can be one or more of the following: spindle speed pulse signal, twisting disc rotation speed signal, yarn rotation photoelectric pulse signal at the twisting end, or tension signal at the twisting end; the second twist-related signal can be one or more of the following: winding end tension signal, yarn guide end tension signal, yarn vibration signal, air ring radius change signal, winding speed signal, or yarn twist detection signal. As long as the collected signals can respectively characterize the twist input state at the twisting end and the response state after the twist is transmitted through the yarn 14, they can all be used as the twist-related signals in this embodiment of the invention.

[0043] It should be further explained that the first twist-related signal and the second twist-related signal in the embodiments of the present invention are both signals that can directly or indirectly reflect the twist input state or twist response state. Among them, the spindle speed pulse signal, the twisting disc speed signal, and the yarn rotation photoelectric pulse signal at the twisting end can reflect the input rhythm and input intensity when the twisting mechanism 1 applies twist to the yarn 14; the tension signal at the twisting end can reflect the force change of the yarn 14 during the twisting input process and can be used as an auxiliary characterization signal for the twist input fluctuation at the twisting end.

[0044] Accordingly, the tension signals at the winding end and the yarn guide end can reflect the force response of the yarn 14 in the subsequent yarn segment after twist transmission; the yarn vibration signal can reflect the dynamic fluctuation state of the yarn 14 during twist transmission; the air circle radius change signal can reflect the stability change of the air circle formed by the yarn 14 during twisting and operation; the winding speed signal can reflect the change in the traction state of the yarn 14 by the winding mechanism 3; and the yarn twist detection signal can directly or indirectly reflect the actual twist state after twist transmission to the yarn forming end. Therefore, the above-mentioned second twist-related signal can serve as a characterization signal of the response state after twist transmission through the yarn 14.

[0045] By synchronizing the first twist correlation signal and the second twist correlation signal within the same control cycle and matching the time window, a correspondence between the twist input state at the twisting end and the response state at the yarn forming end, yarn guiding end, or winding end can be established, thereby identifying the response delay, attenuation change, phase deviation, or reduced correlation that occur when the twist is transmitted in the yarn 14.

[0046] It should also be noted that the twisting device in this embodiment of the invention can be a single-spindle twisting device or a multi-spindle twisting device. When applied to a multi-spindle twisting device, a first detection unit 5 and a second detection unit 6 can be configured for different twisting stations, or the first twist correlation signal and the second twist correlation signal for different stations can be acquired through a multi-channel acquisition method. The processor or controller 15 can calculate the twist hysteresis, twist attenuation state, and twist transmission state of each station, and perform tension compensation, speed compensation, alarm, or spindle stop control separately for abnormal stations to improve the yarn consistency among multiple spindles.

[0047] II. Example 1: System Structure Example

[0048] 2.1 Overall Structure of the Twisting Equipment

[0049] Combination Figure 1 As shown, this embodiment provides a twist tension adaptive compensation control system based on twist hysteresis identification, which is applied to a twisting device. The twisting device includes a twisting mechanism 1, a yarn feeding mechanism 2, a winding mechanism 3, a tension actuation mechanism 4, and yarn 14. The yarn feeding mechanism 2 is used to feed the yarn 14 into the twisting area where the twisting mechanism 1 is located; the twisting mechanism 1 is used to apply twist to the yarn 14; the winding mechanism 3 is used to wind the twisted yarn 14 into shape; and the tension actuation mechanism 4 is used to adjust the operating tension of the yarn 14 during the yarn feeding, twisting, guiding, or winding processes.

[0050] In this embodiment, the twisting device further includes a first detection unit 5, a second detection unit 6, and a processor or controller 15. The first detection unit 5 is located at or near the twisting end and is used to acquire a first twist-related signal. The second detection unit 6 is located at the yarn forming end, yarn guiding end, or winding end and is used to acquire a second twist-related signal. The processor or controller 15 is communicatively connected to the first detection unit 5, the second detection unit 6, the tension actuator 4, the yarn feeding mechanism 2, the winding mechanism 3, and the twisting mechanism 1, respectively, to receive detection signals and output corresponding control commands.

[0051] Specifically, the first twist correlation signal is used to characterize the input rhythm, input intensity, or input fluctuation state of the twisting mechanism 1 applying twist to the yarn 14; the second twist correlation signal is used to characterize the response rhythm, response intensity, or response fluctuation state after the twist is transmitted through the yarn 14. By performing correlation analysis on the first and second twist correlation signals, the processor or controller 15 can identify the twist transmission lag and twist attenuation state between the twisting end and the yarn forming end, yarn guiding end, or winding end, and accordingly perform compensatory control on the tension actuator 4.

[0052] 2.2 Setup of the First Detection Unit

[0053] The first detection unit 5 is used to acquire the first twist correlation signal at the twisting end. The twisting end can be the position where the twisting mechanism 1 applies twist to the yarn 14, or it can be a position close to the twisting mechanism 1 that can reflect the twisting input state. The first detection unit 5 can be set near the rotating parts, twisting disc, spindle, yarn rotation detection area, or twisting end tension detection area of ​​the twisting mechanism 1.

[0054] In one embodiment, the first detection unit 5 may include one or more of a spindle speed sensor, an encoder, a photoelectric sensor, a Hall sensor, and a twisting end tension sensor. Correspondingly, the first twist-related signal may include one or more of a spindle speed pulse signal, a twisting disc rotation speed signal, a twisting end yarn rotation photoelectric pulse signal, and a twisting end tension signal.

[0055] Among them, the spindle speed pulse signal or the twisting disc rotation speed signal can reflect the twisting rhythm and twisting intensity of the twisting mechanism 1; the yarn rotation photoelectric pulse signal at the twisting end can reflect the rotation state of the yarn 14 at the twisting end; and the tension signal at the twisting end can reflect the tension change of the yarn 14 during the twisting input process. The above signals can be used individually or in combination to improve the accuracy of characterizing the twisting input state at the twisting end.

[0056] 2.3 Setting up the second detection unit

[0057] The second detection unit 6 is used to acquire the second twist correlation signal. The second detection unit 6 can be set at the yarn forming end, yarn guiding end, or winding end, or it can be set at a position that can detect the response state after the twist is transmitted by the yarn 14. The yarn forming end, yarn guiding end, or winding end can be the yarn path area after the twisting end, which can reflect the actual transmission result of the twist input from the twisting end in the subsequent yarn segment.

[0058] In one embodiment, the second detection unit 6 may include one or more of the following: a winding end tension sensor, a yarn guide end tension sensor, a yarn vibration sensor, a loop radius detection sensor, a winding speed detector, and a yarn twist detector. Correspondingly, the second twist-related signal may include one or more of the following: a winding end tension signal, a yarn guide end tension signal, a yarn vibration signal, a loop radius change signal, a winding speed signal, and a yarn twist detection signal.

[0059] Among them, the tension signal at the winding end or the tension signal at the yarn guide end can reflect the stress state of the yarn 14 after twist transmission; the yarn vibration signal can reflect the dynamic fluctuations of the yarn 14 during operation; the air ring radius change signal can reflect the change in the air ring state during twisting; the winding speed signal can reflect the change in the traction state of the yarn 14 by the winding mechanism 3; and the yarn twist detection signal can directly or indirectly reflect the yarn state after twist transmission. These signals, used in conjunction with the first twist-related signal, can be used to identify the delay, attenuation, or phase mismatch between the twist input state and the subsequent response state.

[0060] 2.4 Module Structure of Processor or Controller

[0061] The processor or controller 15 is used to process the signals collected by the first detection unit 5 and the second detection unit 6, and output control commands based on the processing results. The processor or controller 15 can be an industrial controller, PLC, embedded controller, edge computing controller, industrial computer or host computer, or it can be a control system composed of multiple control units working together.

[0062] Combination Figure 1 As shown, the processor or controller 15 may include a signal synchronization processing module 7, a twist hysteresis identification module 8, a twist attenuation analysis module 9, a twist transmission state determination module 10, a tension compensation control module 11, a control output module 12, and a closed-loop update module 13. These modules can be implemented through hardware circuits, software programs, or a combination of both.

[0063] The signal synchronization processing module 7 is used to perform synchronization preprocessing on the first twist-related signal and the second twist-related signal. The synchronization preprocessing may include timestamp synchronization, outlier removal, filtering, and amplitude normalization. Specifically, timestamp synchronization is used to eliminate data acquisition time base deviations between the detection positions at the twisting end and the yarn forming end, yarn guiding end, or winding end; outlier removal is used to remove invalid sampling points caused by sudden interference; filtering is used to reduce mechanical vibration, electromagnetic interference, or sensor noise; and amplitude normalization is used to bring the first twist-related signal and the second twist-related signal to the same or similar signal comparison scale.

[0064] The twist hysteresis identification module 8 is used to perform time window matching on the first twist correlation signal and the second twist correlation signal after synchronous preprocessing within a preset sliding time window, and determine the response delay between them. Specifically, the twist hysteresis identification module 8 can set multiple candidate offset times within the preset sliding time window, calculate the correlation between the first twist correlation signal and the second twist correlation signal at each candidate offset time, and determine the candidate offset time corresponding to the maximum correlation as the twist hysteresis amount of the current control cycle.

[0065] The twist attenuation analysis module 9 is used to determine the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first twist-related signal and the second twist-related signal. In one embodiment, the twist attenuation analysis module 9 can determine the twist attenuation coefficient based on the ratio of the change in amplitude or energy of the second twist-related signal relative to the amplitude or energy of the first twist-related signal; it can also determine the phase deviation based on the phase difference between the two types of signals within a preset sliding time window, and determine the degree of transmission correlation between the two types of signals based on the signal correlation coefficient.

[0066] The twist transmission status determination module 10 is used to determine the twist transmission status of the current twisting station based on the twist hysteresis and twist attenuation status. The twist transmission status may include at least one of the following: normal transmission status, increased hysteresis status, increased twist attenuation status, phase mismatch status, tension instability status, and pre-breakage status. By distinguishing between different twist transmission statuses, the system can select different compensation methods according to the actual operating conditions, avoiding overcompensation or undercompensation caused by using a single control strategy.

[0067] The tension compensation control module 11 is used to generate a tension compensation amount based on the twist transmission state. Specifically, the tension compensation control module 11 can determine the adjustment direction and adjustment range of the tension compensation amount based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index. In the state of increased hysteresis, a first compensation component can be determined by combining the hysteresis deviation and the hysteresis compensation coefficient; in the state of increased twist attenuation, a second compensation component can be determined by combining the twist attenuation coefficient and the attenuation compensation coefficient; and in the state of tension instability, a third compensation component can be determined by combining the tension fluctuation index and the tension fluctuation compensation coefficient.

[0068] The control output module 12 is used to output the tension compensation amount to the tension actuator 4, and selectively output the speed compensation amount or speed change slope compensation amount to the yarn feeding mechanism 2, the winding mechanism 3, or the twisting mechanism 1 according to the twist transmission state. For example, in the case of phase mismatch or increased twist attenuation, the control output module 12 can output the speed compensation amount to the yarn feeding mechanism 2 or the winding mechanism 3; during the speed increase or decrease process, the control output module 12 can output the speed change slope compensation amount to the twisting mechanism 1 to reduce the impact of twist transmission mismatch on tension stability.

[0069] The closed-loop update module 13 is used to update the tension compensation parameters for the next control cycle based on the closed-loop residual between the actual tension fluctuation value after compensation and the target tension fluctuation value after tension compensation is completed. The tension compensation parameters may include a hysteresis compensation coefficient, an attenuation compensation coefficient, a tension fluctuation compensation coefficient, and a speed coordination compensation coefficient. Through the closed-loop update module 13, subsequent control parameters can be corrected based on the actual effect after compensation, enabling the system to adapt to changes in yarn type, batch, equipment operating speed, and environmental conditions.

[0070] 2.5 Tension Actuator and Control Connection Relationship

[0071] The tension actuator 4 receives the tension compensation amount output by the control output module 12 and adjusts the running tension of the yarn 14 according to the tension compensation amount. The tension actuator 4 can be an electronic tensioner, a magnetic powder tensioner, a servo tension adjustment mechanism, a pneumatic tension adjustment mechanism, an adjustable damping mechanism, or other actuators capable of changing the yarn tension.

[0072] In one embodiment, the tension actuator 4 can be disposed between the yarn feeding mechanism 2 and the twisting mechanism 1 to adjust the tension of the yarn 14 before it enters the twisting area; it can also be disposed between the twisting mechanism 1 and the winding mechanism 3 to adjust the running tension of the twisted yarn 14; or the tension actuator 4 can be disposed in multiple locations to achieve segmented tension compensation control. This invention does not limit the specific installation location and structural form of the tension actuator 4, as long as it can change the tension state of the yarn 14 according to the control commands of the control output module 12.

[0073] The yarn feeding mechanism 2, winding mechanism 3, and twisting mechanism 1 can each be communicatively connected to the control output module 12. In addition to outputting tension compensation to the tension actuator 4, the control output module 12 can also output yarn feeding speed compensation to the yarn feeding mechanism 2, winding speed compensation to the winding mechanism 3, or spindle speed compensation or spindle speed change slope compensation to the twisting mechanism 1, depending on the twist transmission status. Through the above control connections, coordinated control between tension adjustment and speed adjustment can be achieved.

[0074] 2.6 System Layout in Multi-Spindle Equipment

[0075] When this embodiment is applied to a multi-spindle twisting equipment, each twisting station can be configured with a corresponding first detection unit 5 and a second detection unit 6 to acquire the first twisting correlation signal and the second twisting correlation signal of each station, respectively. The processor or controller 15 can calculate the twisting hysteresis, twisting attenuation state and twisting transmission state of different twisting stations, and generate the tension compensation amount of the corresponding station, respectively.

[0076] In another embodiment, the multi-spindle twisting equipment can also use a multi-channel acquisition device to acquire detection signals from different twisting stations, and process them separately by the same processor or controller 15. For stations in normal transmission state, the original process parameters can be maintained; for stations with increased hysteresis, tension instability, or signs of impending spindle breakage, tension compensation, speed compensation, pre-speed reduction, tension release, alarm, or spindle stop control can be executed separately.

[0077] By implementing the above system layout, the impact of individual workstation anomalies on the overall machine operation can be reduced, tension consistency and yarn consistency among multiple spindles can be improved, and the reliance on manual inspection and manual machine adjustment can be reduced.

[0078] III. Example 2: Control Method Example

[0079] Combination Figure 2 As shown, this embodiment provides an adaptive compensation control method for twist tension based on twist hysteresis identification. This method can be implemented by... Figure 1 The processor or controller 15 shown can execute the operation, or it can be executed by an industrial controller, PLC, edge controller, or host computer installed on the twisting equipment. This method mainly identifies the transmission lag and attenuation state of twist in the yarn 14 by collecting the first twist correlation signal at the twisting end and the second twist correlation signal at the yarn forming end, yarn guiding end, or winding end, and performs adaptive compensation control on the tension actuator 4 based on the identification results.

[0080] 3.1 Step S101: Obtain the first twist correlation signal

[0081] The processor or controller 15 acquires the first twist correlation signal at the twisting end through the first detection unit 5. The first twist correlation signal is used to characterize the input rhythm, input intensity, or input fluctuation state of the twisting mechanism 1 applying twist to the yarn 14.

[0082] In one embodiment, the first detection unit 5 may be located near the spindle, twisting disc, rotating component, or yarn detection area at the twisting end of the twisting mechanism 1. The first twist-related signal may be one or more of the following: spindle speed pulse signal, twisting disc rotation speed signal, yarn rotation photoelectric pulse signal at the twisting end, or tension signal at the twisting end.

[0083] For example, when the first detection unit 5 is an encoder or spindle speed sensor, the processor or controller 15 can acquire the spindle speed pulse signal and determine the rotation cycle or twisting intensity of the twisting mechanism 1 based on the number of pulses per unit time; when the first detection unit 5 is a photoelectric sensor, the rotation photoelectric pulse signal of the yarn at the twisting end can be obtained by detecting the rotation cycle or reflection change of the yarn 14 at the twisting end; when the first detection unit 5 is a tension sensor, the tension signal at the twisting end can be acquired to reflect the force change of the yarn 14 during the twisting input process.

[0084] 3.2 Step S102: Obtain the second twist correlation signal

[0085] The processor or controller 15 acquires the second twist correlation signal through the second detection unit 6. The second detection unit 6 can be located at the yarn forming end, the yarn guiding end, or the winding end. The second twist correlation signal is used to characterize the response rhythm, response intensity, or response fluctuation state after the twisted warp yarn 14 is transmitted.

[0086] In one embodiment, the second detection unit 6 may include a winding end tension sensor, a yarn guide end tension sensor, a yarn vibration sensor, a loop radius detection sensor, a winding speed detector, or a yarn twist detector. The second twist-related signal may be one or more of the following: a winding end tension signal, a yarn guide end tension signal, a yarn vibration signal, a loop radius change signal, a winding speed signal, or a yarn twist detection signal.

[0087] The second twist-related signal is within the same control cycle as the first twist-related signal. By comparing the input state at the twisting end with the response state of the subsequent yarn segment, the delay, attenuation, or phase deviation of the twist during transmission can be obtained, thus providing a basis for subsequent tension compensation.

[0088] 3.3 Step S103: Signal Synchronization Preprocessing

[0089] After acquiring the first twist-correlation signal and the second twist-correlation signal, the signal synchronization processing module 7 performs synchronization preprocessing on the two types of signals. Synchronization preprocessing may include timestamp synchronization, outlier removal, filtering, and amplitude normalization.

[0090] Timestamp synchronization is used to eliminate the data acquisition time base deviation between the first detection unit 5 and the second detection unit 6, enabling the two types of signals to be compared under the same control cycle or the same time reference. Outlier removal is used to eliminate invalid data points caused by sensor jitter, electromagnetic interference, instantaneous yarn fluctuations, or sampling anomalies. Filtering is used to reduce the impact of mechanical vibration, environmental noise, or electrical interference on the signal waveform. Amplitude normalization is used to bring the first twist-correlated signal and the second twist-correlated signal to the same or similar comparison scale, facilitating subsequent correlation calculations and attenuation analysis.

[0091] In one implementation, the signal synchronization processing module 7 can perform mean removal, bandpass filtering, or moving average filtering on the first twist-correlated signal and the second twist-correlated signal, respectively, and then normalize the processed signals according to the maximum amplitude, root mean square value, or standard deviation. The normalized signal can be represented as a dimensionless signal, thereby reducing the impact of dimensional differences between different types of sensors on the matching results.

[0092] 3.4 Step S104: Match time windows and determine twist hysteresis.

[0093] Within a preset sliding time window, the twist hysteresis identification module 8 performs time window matching on the first and second twist correlation signals after synchronous preprocessing, and determines the response delay between them. This response delay is used as the twist hysteresis amount for the current control cycle.

[0094] Specifically, multiple candidate offset times can be set within a preset sliding time window. For each candidate offset time, the correlation between the first twist correlation signal and the second twist correlation signal is calculated. When the correlation corresponding to a certain candidate offset time reaches its maximum value, that candidate offset time is determined as the twist hysteresis of the current control cycle.

[0095] For example, the first twist correlation signal can be denoted as X(t), the second twist correlation signal as Y(t), and the candidate offset time as τ. The twist hysteresis identification module 8 can calculate the correlation between X(t) and Y(t+τ) or Y(t-τ), and select the τ corresponding to the highest correlation among multiple candidate offset times as the twist hysteresis. In this way, the response delay generated when the input state at the twisting end is transmitted to the yarn forming end, yarn guiding end, or winding end can be identified.

[0096] When the maximum correlation is lower than the preset confidence threshold, it indicates that the correlation between the two types of signals within the current time window is insufficient. In this case, the preset sliding time window can be extended to obtain more stable signal characteristics; alternatively, the hysteresis of the previous control cycle can be used as the initial constraint value for the current control cycle to avoid sudden changes in hysteresis judgment due to instantaneous interference.

[0097] 3.5 Step S105: Determine the twist attenuation state

[0098] The twist attenuation analysis module 9 determines the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first twist correlation signal and the second twist correlation signal.

[0099] In one implementation, the amplitude attenuation degree can be determined based on the ratio of the amplitude change of the second twist-correlated signal to the amplitude change of the first twist-correlated signal; alternatively, the energy attenuation degree can be determined based on the ratio of the energy change of the second twist-correlated signal to the energy change of the first twist-correlated signal. The energy can be determined based on the sum of squares, mean square value, or root mean square value of the signal within a preset sliding time window.

[0100] In another implementation, the phase deviation can be determined based on the phase difference between the first twist correlation signal and the second twist correlation signal within a preset sliding time window, and the correlation between the input state at the twisting end and the response state of the subsequent yarn segment can be determined based on the signal correlation coefficient. When the amplitude ratio or energy ratio decreases, the phase deviation increases, or the correlation coefficient decreases, it can be considered that there is a trend of increased attenuation, phase mismatch, or decreased transmission correlation during the twist transmission process.

[0101] In this embodiment, the twist attenuation state is not limited to a single parameter determination, but can be determined by multiple parameters. For example, a twist transmission state vector can be constructed that includes twist hysteresis, twist attenuation coefficient, phase deviation, signal correlation coefficient, and tension fluctuation index. This state vector can comprehensively reflect the twist transmission quality of the current twisting station.

[0102] 3.6 Step S106: Determine the twist transmission status

[0103] The twist transmission status determination module 10 determines the twist transmission status of the current twisting station based on the twist hysteresis and twist attenuation status. The twist transmission status may include at least one of the following: normal transmission status, hysteresis increase status, twist attenuation increase status, phase mismatch status, tension instability status, and pre-breakage status.

[0104] In one implementation, when the twist hysteresis is within the target hysteresis range, the twist attenuation coefficient is within the target attenuation range, and the tension fluctuation index does not exceed the preset fluctuation threshold, it can be determined that the current twisting station is in a normal transmission state.

[0105] When the twist hysteresis increases for multiple consecutive control cycles, or when the twist hysteresis exceeds a preset hysteresis threshold, the current twisting station can be determined to be in a state of increasing hysteresis. When the twist attenuation coefficient is lower than a preset attenuation threshold, or when the amplitude ratio or energy ratio continuously decreases, the current twisting station can be determined to be in a state of increasing twist attenuation. When the phase deviation exceeds a preset phase threshold, or when the signal correlation coefficient is lower than a preset correlation threshold, the current twisting station can be determined to be in a state of phase mismatch.

[0106] When the twist hysteresis increases for several consecutive control cycles and the tension fluctuation index exceeds the preset fluctuation threshold, it can be determined that the current twisting station is in a state of tension instability. When the twist hysteresis exceeds the preset hysteresis threshold, the signal correlation coefficient is lower than the preset correlation threshold, and the second twist correlation signal shows a sudden drop or rise, it can be determined that the current twisting station is in a state of impending thread breakage.

[0107] By using the above-mentioned status determination, different types of abnormal states can be distinguished, so that subsequent compensation control can be adjusted according to the specific cause, rather than simply making uniform adjustments based on a single point tension deviation.

[0108] 3.7 Step S107: Generate tension compensation amount

[0109] The tension compensation control module 11 generates a tension compensation amount based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index. The tension compensation amount includes the adjustment direction and the adjustment amplitude.

[0110] In one implementation, when the twist transmission state is in a state of increased hysteresis, a first compensation component can be determined based on the product of the hysteresis deviation and a preset hysteresis compensation coefficient. The hysteresis deviation can be the difference between the current twist hysteresis and the target hysteresis.

[0111] When the twist transmission state is in a state of increased twist attenuation, the second compensation component can be determined based on the product of the twist attenuation coefficient and the preset attenuation compensation coefficient. When the twist transmission state is in a state of tension instability, the third compensation component can be determined based on the product of the tension fluctuation index and the preset tension fluctuation compensation coefficient. The tension compensation control module 11 can determine the adjustment range of the tension compensation amount based on at least one of the first compensation component, the second compensation component, and the third compensation component.

[0112] The adjustment direction of the tension compensation amount can be determined based on the sign of the hysteresis deviation, the deviation of the twist attenuation coefficient from the target attenuation coefficient, and the deviation of the tension signal from the target tension value. For example, when the tension signal is higher than the target tension value and the tension fluctuation index increases, the tension actuator 4 can be controlled to reduce the output; when the tension signal is lower than the target tension value and the twist transmission state is unstable, the tension actuator 4 can be controlled to increase the output or adjust in conjunction with speed compensation. The specific adjustment direction can be preset according to the yarn type, equipment structure, and process requirements.

[0113] 3.8 Step S108: Output Compensation Control

[0114] The control output module 12 outputs the tension compensation amount to the tension actuator 4, causing the tension actuator 4 to adjust the running tension of the yarn 14. The tension actuator 4 can adjust the tension by changing the damping, clamping force, braking force, servo position, air pressure, or electromagnetic output.

[0115] In one implementation, when the current workstation is in a state of increased lag, the control output module 12 mainly outputs tension compensation to the tension actuator 4 to adjust the force state of the yarn 14 during twisting and transmission. When the current workstation is in a state of increased twist attenuation, the control output module 12 can also output speed compensation to the yarn feeding mechanism 2 or the winding mechanism 3 to change the conveying or traction state of the yarn 14. When the current workstation is in a state of phase mismatch, the control output module 12 can reduce the slope of spindle speed change, yarn feeding speed change, or winding speed change, so that the twisting input change gradually matches the response change of the subsequent yarn segment.

[0116] When the current workstation is in a state of impending yarn breakage, the control output module 12 can perform pre-speed reduction, tension release, alarm, or spindle stop control on the corresponding twisting workstation. In this way, the stress impact on the yarn 14 can be reduced before yarn breakage occurs, thereby reducing the risk of yarn breakage, or the spindle can be stopped in time when the abnormal state is irreversible, so as to reduce the impact of waste yarn and equipment malfunction.

[0117] 3.9 Step S109: Closed-loop update of compensation parameters for the next control cycle

[0118] After tension compensation, the second detection unit 6 acquires the second twist correlation signal again. The closed-loop update module 13 calculates the closed-loop residual between the compensated actual tension fluctuation value and the target tension fluctuation value based on the compensated second twist correlation signal, and updates the tension compensation parameters for the next control cycle based on the closed-loop residual.

[0119] The tension compensation parameters may include a hysteresis compensation coefficient, an attenuation compensation coefficient, a tension fluctuation compensation coefficient, and a speed coordination compensation coefficient. When the closed-loop residual is less than a preset residual threshold, it indicates that the current compensation effect meets the control requirements, and the current tension compensation parameters can be maintained. When the closed-loop residual is greater than or equal to the preset residual threshold, it indicates that the current compensation effect is insufficient or there is a deviation, and at least one of the hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, and speed coordination compensation coefficient can be updated based on the closed-loop residual.

[0120] In one implementation, the update step size of the compensation coefficient can be adjusted according to the magnitude of the closed-loop residual. When the closed-loop residual is large, a larger update step size is used to improve the compensation response speed; when the closed-loop residual is small, a smaller update step size is used to avoid control oscillations. Through closed-loop updates, the system can gradually correct the compensation parameters according to changes in yarn type, batch, operating speed, and environmental conditions, thereby improving the adaptive capability of tension control.

[0121] 3.10 Technical Effects of this Embodiment

[0122] The control method of this embodiment can establish a correspondence between the input state of the twisting end and the response state of the yarn forming end, yarn guiding end, or winding end within the same control cycle. It can also identify the hysteresis and attenuation state during the twist transmission process online and generate tension compensation based on different twist transmission states. Compared to closed-loop adjustment based solely on a single-point tension signal, this embodiment can more accurately reflect the twist transmission process in the yarn 14, reducing the possibility of compensation hysteresis, incorrect compensation direction, and mismatched compensation amplitude.

[0123] Meanwhile, this embodiment updates the compensation parameters for the next control cycle through closed-loop residuals, enabling tension compensation control to adapt to working conditions such as speed increase, speed decrease, start-up and shutdown, product change, batch change, and changes in environmental conditions. This helps to reduce tension fluctuations, improve twist uniformity, reduce the risk of yarn breakage, and improve the yarn consistency of multi-spindle twisting equipment.

[0124] IV. Example 3: Multi-spindle independent compensation example

[0125] This embodiment, based on Embodiments 1 and 2 above, further illustrates the application of the present invention in a multi-spindle twisting device. A multi-spindle twisting device typically includes multiple twisting stations arranged in parallel, each completing processes such as yarn feeding, twisting, tension adjustment, and winding. Because yarn batches, guiding resistance, tension conditions, air ring conditions, and mechanical transmission conditions may differ between stations, even if the entire machine uses the same process parameters, issues such as different twist transmission lags, different tension fluctuations, or inconsistent yarn quality may occur between stations.

[0126] Combination Figure 1As shown, in one embodiment, each twisting station is equipped with a corresponding first detection unit 5 and a second detection unit 6. The first detection unit 5 is located at the twisting end of the corresponding station and is used to acquire the first twist correlation signal of that station; the second detection unit 6 is located at the yarn forming end, yarn guiding end, or winding end of the corresponding station and is used to acquire the second twist correlation signal of that station. The processor or controller 15 receives the first twist correlation signal and the second twist correlation signal of each station respectively, and distinguishes and processes the collected data according to the station number.

[0127] In another embodiment, the multi-spindle twisting equipment can employ a multi-channel signal acquisition device to acquire the detection signals from each station. The multi-channel signal acquisition device can be communicatively connected to multiple first detection units 5 and multiple second detection units 6, respectively, and transmit the detection signals from different stations to the processor or controller 15. The processor or controller 15 can establish an independent data buffer, sliding time window, and compensation parameter set for each station to calculate the twist hysteresis, twist attenuation state, and twist transmission state of each station.

[0128] For any twisting station, the processor or controller 15 can acquire the first twist-related signal and the second twist-related signal of that station within the same control cycle, and perform timestamp synchronization, outlier removal, filtering, and amplitude normalization through the signal synchronization processing module 7. Subsequently, the twist hysteresis identification module 8 performs time window matching on the two types of signals of the station within a preset sliding time window to determine the twist hysteresis of the station. The twist attenuation analysis module 9 determines the twist attenuation state of the station based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the two types of signals of the station.

[0129] The twist transmission state determination module 10 determines the twist transmission state of each station based on the twist hysteresis and twist attenuation state of each station. The twist transmission state may include at least one of the following: normal transmission state, hysteresis increase state, twist attenuation increase state, phase mismatch state, tension instability state, and pre-breakage state. The twist transmission states of different stations may be the same or different.

[0130] When a certain station is in normal transmission state, the processor or controller 15 can maintain the original tension compensation parameters, yarn feeding speed parameters, winding speed parameters, or spindle speed parameters of that station, so that the station continues to operate according to the current process conditions. When a certain station is in a state of increased lag, the tension compensation control module 11 can generate a corresponding tension compensation amount based on the lag deviation of the twist lag amount of that station relative to the target lag amount, and output the tension compensation amount to the tension actuator 4 of that station through the control output module 12.

[0131] When a certain workstation experiences increased twist attenuation, the processor or controller 15 can combine the twist attenuation coefficient, phase deviation, and tension fluctuation index of that workstation to generate a tension compensation amount, and selectively output a speed compensation amount to the yarn feeding mechanism 2 or winding mechanism 3 of that workstation. By coordinating tension compensation and speed compensation, the matching relationship between the input state of the twisting end in that workstation and the response state of the subsequent yarn segment can be improved, reducing twist fluctuations caused by twist transmission attenuation.

[0132] When a certain workstation is in a phase mismatch state, the control output module 12 can reduce the slope of the spindle speed change of the twisting mechanism 1, the slope of the yarn feeding speed change of the yarn feeding mechanism 2, or the slope of the winding speed change of the winding mechanism 3 at that workstation, so that the change in twisting input and the response change of subsequent yarn segments gradually return to matching. This control method is particularly suitable for situations where the responses of individual workstations are not synchronized during the overall machine speed increase, speed decrease, or process switching.

[0133] When a certain workstation is in a state of tension instability, the tension compensation control module 11 can determine the tension compensation amount based on the tension fluctuation index and tension fluctuation compensation coefficient of that workstation, and perform compensation control on the tension actuator 4 of that workstation through the control output module 12. If the tension fluctuation index of that workstation is still higher than the preset fluctuation threshold within multiple control cycles, the processor or controller 15 can further reduce the yarn feeding speed, winding speed or spindle speed of that workstation to reduce the dynamic impact on the yarn 14.

[0134] When a workstation is in a state of impending spindle breakage, the control output module 12 can perform pre-speed reduction, tension release, alarm, or spindle stop control on that workstation. Specifically, it can first reduce the operating speed of the twisting mechanism 1 or winding mechanism 3 at that workstation, while simultaneously controlling the tension actuator 4 to release or reduce tension; if the second twist correlation signal still shows a sudden drop or rise, or the signal correlation coefficient remains below the preset correlation threshold, then spindle stop control is performed on that workstation and an alarm message is output. Other workstations that do not show any abnormalities can continue to operate according to the original set parameters.

[0135] During the multi-spindle independent compensation process, the closed-loop update module 13 can record the changes in the second twist correlation signal before and after compensation at each workstation, and calculate the closed-loop residual between the actual tension fluctuation value and the target tension fluctuation value after compensation at each workstation. When the closed-loop residual of a certain workstation is less than the preset residual threshold, the current tension compensation parameters of that workstation are maintained; when the closed-loop residual of that workstation is greater than or equal to the preset residual threshold, the hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, or speed coordination compensation coefficient of that workstation are updated according to the closed-loop residual.

[0136] In one specific application, a multi-spindle twisting device includes several parallel stations, each equipped with a tension actuator 4. A processor or controller 15 periodically collects the first and second twist correlation signals for each station and calculates the twist hysteresis for each station. If the twist hysteresis of the Nth station increases for several consecutive control cycles, and the tension fluctuation index exceeds a preset fluctuation threshold, while other stations are in normal operation, the processor or controller 15 outputs tension compensation only to the tension actuator 4 of the Nth station and can selectively reduce the winding speed change slope of that station. Other stations continue to operate according to their original process parameters.

[0137] Through the above methods, this embodiment enables independent status identification and compensation control of each station in a multi-spindle twisting machine. Compared to a unified adjustment of the entire machine, this embodiment avoids the impact of a single station's malfunction on the operation of other normal stations, reducing the likelihood of the entire machine slowing down or stopping. Furthermore, since the tension compensation parameters of each station can be updated independently based on its own compensation effect, it can better adapt to differences in mechanical properties, yarn properties, and operating conditions between different stations. This helps improve tension consistency and yarn consistency across multiple spindles and reduces the risk of yarn breakage.

[0138] V. Example 4: Typical Operating Scenario Example

[0139] This embodiment, based on the above embodiments, further illustrates the control process of the present invention in conjunction with typical operating scenarios of a yarn twisting device. It should be understood that the following operating scenarios are only used to illustrate the application of the present invention under different working conditions and do not constitute a limitation on the scope of protection of the present invention.

[0140] ### 5.1 Acceleration Phase

[0141] During the transition from low-speed to high-speed operation of the twisting equipment, the spindle speed of the twisting mechanism 1, the yarn feeding speed of the yarn feeding mechanism 2, and the winding speed of the winding mechanism 3 typically change synchronously or in stages. Because the yarn 14 possesses certain elasticity, frictional characteristics, and torsional transmission characteristics, changes in the twist input at the twisting end are not immediately transmitted to the yarn forming end, yarn guiding end, or winding end, which can easily lead to increased twist hysteresis, increased phase deviation, or aggravated tension fluctuations.

[0142] In this scenario, the first detection unit 5 acquires the first twist-related signal at the twisting end, and the second detection unit 6 acquires the second twist-related signal at the yarn forming end, yarn guiding end, or winding end. After synchronously preprocessing the two types of signals, the processor or controller 15 calculates the twist hysteresis amount within the current control cycle through the twist hysteresis identification module 8, and determines the twist attenuation state through the twist attenuation analysis module 9.

[0143] When the processor or controller 15 determines that the twist hysteresis has increased for multiple consecutive control cycles, or that the twist hysteresis has exceeded a preset hysteresis threshold, the twist transmission status determination module 10 can determine that the current twisting station is in a state of increasing hysteresis. At this time, the tension compensation control module 11 generates a tension compensation amount based on the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and outputs the tension compensation amount to the tension actuator 4 through the control output module 12.

[0144] During the speed-up process, if an increase in phase deviation or a decrease in signal correlation coefficient is detected simultaneously, the control output module 12 can further reduce the slope of the spindle speed change of the twisting mechanism 1, the slope of the yarn feeding speed change of the yarn feeding mechanism 2, or the slope of the winding speed change of the winding mechanism 3, so that the input change at the twisting end gradually matches the response change of the subsequent yarn segment. This control method can reduce tension spikes and twist fluctuations caused by the lag in twist transmission during the speed-up phase, thereby improving the yarn running stability during the speed-up process.

[0145] 5.2 Speed ​​reduction or shutdown phase

[0146] During the deceleration or shutdown of the twisting equipment, the operating speeds of the twisting mechanism 1, the yarn feeding mechanism 2, and the winding mechanism 3 gradually decrease. Due to the different inertia, response speed, and control delay of the different mechanisms, the force state of the yarn 14 in the running path is prone to change, which in turn causes fluctuations in the second twist-related signal at the yarn forming end, the yarn guiding end, or the winding end.

[0147] In this scenario, the processor or controller 15 continuously acquires the first twist correlation signal and the second twist correlation signal, and determines the twist transmission status based on the correlation, phase difference, and tension fluctuation index of the two types of signals. When the tension fluctuation index is detected to exceed the preset fluctuation threshold, and the twist hysteresis amount shows abnormal changes, it can be determined that there is a risk of tension instability at the current twisting station.

[0148] At this time, the tension compensation control module 11 can determine the tension compensation amount based on the tension fluctuation index and the preset tension fluctuation compensation coefficient, and control the tension actuator 4 to smoothly adjust the tension of the yarn 14. Simultaneously, the control output module 12 can adjust the yarn feeding speed, winding speed, or spindle speed change slope based on the speed coordination compensation coefficient, ensuring good coordination among the mechanisms during deceleration or shutdown. Through the above control, the risks of yarn slack, sudden tension increases, or poor winding caused by speed mismatch during deceleration or shutdown can be reduced.

[0149] 5.3 Variety or Batch Change Stage

[0150] When the yarn type or batch changes, the linear density, elasticity, frictional properties, torsional stiffness, and surface condition of yarn 14 may change. Even if the twisting equipment uses the original process parameters, the twist transmission speed, attenuation degree, and tension response of different yarns may differ. Therefore, if the original empirical parameters are still relied upon for control after changing the yarn type or batch, problems such as untimely compensation or mismatched compensation magnitude are likely to occur.

[0151] In this scenario, during the initial operation phase after a change in product type or batch, the processor or controller 15 re-acquires the first twist correlation signal and the second twist correlation signal, and recalculates the twist hysteresis, twist attenuation coefficient, phase deviation, signal correlation coefficient, and tension fluctuation index. The closed-loop update module 13 updates at least one of the hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, and speed coordination compensation coefficient based on the closed-loop residual between the compensated actual tension fluctuation value and the target tension fluctuation value.

[0152] For example, when the twist attenuation coefficient of a new batch of yarn is lower than the target attenuation coefficient, the system can determine that the yarn has a tendency to increase twist attenuation under the current process conditions. The tension compensation control module 11 generates a compensation component based on the twist attenuation coefficient and the attenuation compensation coefficient, and the control output module 12 can further output a speed compensation amount to the yarn feeding mechanism 2 or the winding mechanism 3. In this way, the process stabilization time after changing varieties or batches can be shortened, and the need for repeated manual machine adjustments can be reduced.

[0153] 5.4 Precursor Stages of Decapitation

[0154] During the twisting process, if yarn 14 is subjected to excessive tension impact, airflow fluctuations, sudden changes in guide friction, or abnormal winding, there may be a risk of yarn breakage. Before the breakage occurs, the second twist correlation signal may show a sudden drop, a sudden rise, abnormal fluctuations, or a significant decrease in correlation with the first twist correlation signal.

[0155] In this scenario, when the processor or controller 15 detects that the twisting hysteresis exceeds the preset hysteresis threshold, the signal correlation coefficient is lower than the preset correlation threshold, and the second twisting associated signal suddenly drops or rises, the twisting transmission status determination module 10 can determine that the current twisting station is in a state of impending breakage.

[0156] At this time, the control output module 12 can perform pre-speed reduction control on the corresponding workstation, reducing the operating speed of the twisting mechanism 1, the yarn feeding mechanism 2, or the winding mechanism 3; simultaneously, it controls the tension actuator 4 to release or reduce tension to reduce the instantaneous tensile impact on the yarn 14. If the second twist-related signal returns to the normal range after pre-speed reduction and tension release, the system can update the compensation parameters according to the closed-loop residual and gradually restore normal operation. If the second twist-related signal remains abnormal, the control output module 12 can execute alarm or spindle stop control to avoid increased yarn breakage, increased waste yarn, or impact on the operation of other workstations.

[0157] 5.5 Multi-spindle localized abnormality stage

[0158] In multi-spindle twisting equipment, different stations may exhibit different twist transmission states due to differences in yarn guide paths, tension actuator response, winding conditions, or local yarn quality. For example, a certain station may experience increased twist lag, while other stations maintain normal transmission.

[0159] In this scenario, the processor or controller 15 independently analyzes the first and second twist-related signals of each station and determines the twist transmission status of each station. When a station experiences increased hysteresis, tension instability, or signs of impending spindle breakage, the control output module 12 only outputs tension compensation, speed compensation, pre-deceleration command, tension release command, or spindle stop command to that station. Other stations in normal transmission status continue to operate according to their original process parameters.

[0160] This method avoids the need for a unified speed reduction or shutdown of the entire machine due to an anomaly at a single workstation, reducing the impact of localized anomalies on overall production efficiency. Simultaneously, the compensation parameters for each workstation can be updated independently based on its own closed-loop residual, which helps improve tension consistency and yarn consistency across multiple spindles.

[0161] VI. Example 5: Storage Medium and Program Implementation Example

[0162] This embodiment describes the method of the present invention implemented by a computer program, based on the above embodiments. The twist tension adaptive compensation control method based on twist hysteresis identification provided by this embodiment can be implemented by a computer program, control program, embedded software, PLC control logic, or industrial control algorithm, and can be stored in a computer-readable storage medium. When the program is executed by the processor or controller 15, it can achieve… Figure 2 The control method flow is shown.

[0163] In one embodiment, the computer-readable storage medium stores a computer program including program instructions for performing the following steps: acquiring a first twist correlation signal at the twisting end; acquiring a second twist correlation signal at the yarn forming end, yarn guiding end, or winding end; performing synchronous preprocessing on the first twist correlation signal and the second twist correlation signal; performing time window matching on the two types of signals after synchronous preprocessing within a preset sliding time window to determine the twist lag; determining the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the two types of signals; determining the twist transmission state based on the twist lag and the twist attenuation state; generating a tension compensation amount based on the twist transmission state; and updating the tension compensation parameters for the next control cycle based on the compensated closed-loop residual.

[0164] The computer-readable storage medium may include a read-only memory, random access memory, flash memory, hard disk, solid-state drive, memory card, storage unit of a programmable logic controller, storage unit of an industrial computer, storage unit of an edge controller, or other media capable of storing program instructions. This embodiment does not limit the specific type of storage medium, as long as it can store program instructions that can be read and executed by the processor or controller 15.

[0165] In one embodiment, the processor or controller 15 can be a PLC, an embedded controller, an industrial computer, an edge computing controller, a host computer, or a control system composed of multiple control units. When the processor or controller 15 executes the computer program, it can call the data collected by the first detection unit 5 and the second detection unit 6, and control the tension actuator 4, the yarn feeding mechanism 2, the winding mechanism 3, or the twisting mechanism 1 to perform corresponding compensation actions.

[0166] Specifically, when executing the program, the processor or controller 15 can first establish data buffers for the first and second twist-correlation signals, and sample the two types of signals according to the control cycle. For each control cycle, the program can perform timestamp synchronization, outlier removal, filtering, and amplitude normalization on the two types of signals, so that the two types of signals are at a unified time reference and comparable amplitude scale.

[0167] Subsequently, the program sets multiple candidate offset times within a preset sliding time window and calculates the correlation between the first and second twist-related signals at each candidate offset time. The program determines the candidate offset time corresponding to the maximum correlation as the twist hysteresis of the current control cycle. When the maximum correlation is lower than a preset confidence threshold, the program can extend the sliding time window or use the twist hysteresis of the previous control cycle as the initial constraint value for the current control cycle to reduce the impact of instantaneous noise or abnormal sampling on the judgment result.

[0168] The program can also calculate the twist attenuation coefficient, phase deviation, signal correlation coefficient, and tension fluctuation index based on the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first twist-related signal and the second twist-related signal, thereby forming a twist transmission state vector. Based on this state vector, the program can determine whether the current twisting position is in a normal transmission state, a state of increased hysteresis, a state of increased twist attenuation, a state of phase mismatch, a state of tension instability, or a state of impending breakage.

[0169] After determining the twist transmission state, the program can calculate the adjustment direction and amplitude of the tension compensation amount based on the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, the deviation of the twist attenuation coefficient relative to the target attenuation coefficient, and the tension fluctuation index. The processor or controller 15 generates a control command based on the tension compensation amount and outputs the control command to the tension actuator 4 through the control output module 12, so that the tension actuator 4 compensates and adjusts the running tension of the yarn 14.

[0170] When the twist transmission state is in a phase mismatch state, a twist attenuation increase state, or a tension instability state, the program can also generate a speed compensation amount or a speed change slope compensation amount based on the speed coordination compensation coefficient, and output it to the yarn feeding mechanism 2, the winding mechanism 3, or the twisting mechanism 1. In this way, the tension compensation can be coordinated with the adjustment of the yarn feeding speed, winding speed, or spindle speed, reducing the twist transmission mismatch caused by asynchronous responses of various mechanisms.

[0171] After completing the compensation control, the program can read the second twist correlation signal collected by the second detection unit 6 again and calculate the closed-loop residual between the compensated actual tension fluctuation value and the target tension fluctuation value. When the closed-loop residual is less than the preset residual threshold, the program maintains the current tension compensation parameters; when the closed-loop residual is greater than or equal to the preset residual threshold, the program updates at least one of the hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, and speed coordination compensation coefficient according to the closed-loop residual for use in the next control cycle.

[0172] In multi-spindle twisting equipment, the program can establish independent data buffers, status judgment variables, and compensation parameter groups for different twisting stations. For each twisting station, the program calculates its twist hysteresis, twist attenuation state, and twist transmission state, and outputs the corresponding tension compensation or speed compensation. When a station shows signs of impending spindle breakage, the program can only perform pre-speed reduction, tension release, alarm, or spindle stop control on that station without affecting the continued operation of other normal stations.

[0173] Through the above-described implementation method, the control method of the present invention can be deployed in the local controller of the twisting equipment, industrial computer, PLC, edge controller, or host computer, or it can be executed collaboratively by multiple control units. This implementation method facilitates the integration of twist hysteresis identification, twist attenuation analysis, tension compensation control, and closed-loop parameter updates into the existing control system of the twisting equipment, thereby improving the adaptive capability and operational stability of the equipment's tension control.

[0174] VII. Description of the Effects of the Example

[0175] As can be seen from the above embodiments, the twist tension adaptive compensation control method, system, and computer-readable storage medium based on twist hysteresis identification provided by the present invention can simultaneously acquire the first twist correlation signal at the twisting end and the second twist correlation signal at the yarn forming end, yarn guiding end, or winding end during the twisting process. Through time window matching and correlation analysis between the two types of signals, the twist transmission relationship between the input state at the twisting end and the response state of the subsequent yarn segment can be identified. Compared to methods that rely solely on single-point tension signals or fixed process parameters for control, the present invention can more accurately reflect the actual transmission process of twist in the yarn 14.

[0176] This invention determines the response delay between the first twist-related signal and the second twist-related signal through the twist hysteresis identification module 8, and uses this response delay as the twist hysteresis amount. This allows the processor or controller 15 to know the time required for the input change at the twisting end to be transmitted to the yarn forming end, yarn guiding end, or winding end. Therefore, when generating the tension compensation amount, not only is the current tension considered to deviate from the target value, but also the impact of the twist transmission hysteresis on subsequent tension and twist changes, thereby improving the timeliness of tension compensation.

[0177] This invention uses a twist attenuation analysis module 9 to determine the twist attenuation state based on at least two parameters among amplitude ratio, energy ratio, phase difference, and correlation coefficient. This allows the system to determine whether amplitude attenuation, energy attenuation, phase deviation, or reduced correlation occurs during the transmission of the input twist at the twisting end. This method avoids misjudgments caused by judging the equipment status solely based on a single tension value, enabling the system to more precisely distinguish between different states such as increased twist attenuation, phase mismatch, and tension instability.

[0178] This invention classifies the current twisting station's operating state into various types, including normal transmission state, increased hysteresis state, increased twist attenuation state, phase mismatch state, tension instability state, and pre-breakage state, through the twist transmission state determination module 10. For each different state, the tension compensation control module 11 can determine different compensation components and strategies, making tension compensation more targeted and reducing overcompensation, undercompensation, or incorrect compensation direction.

[0179] This invention uses a tension compensation control module 11 to determine the tension compensation amount based on the twist transmission state, hysteresis deviation, and tension fluctuation index, and outputs the compensation amount to the tension actuator 4 via a control output module 12. This enables adaptive adjustment of the running tension of the yarn 14. When twist hysteresis increases, compensation can be made based on the hysteresis deviation; when twist attenuation increases, adjustment can be made in conjunction with the attenuation compensation coefficient; and when tension becomes unstable, the compensation amplitude can be corrected in conjunction with the tension fluctuation index. This helps reduce tension fluctuation and improve twist uniformity.

[0180] This invention can also output speed compensation or speed change slope compensation to the yarn feeding mechanism 2, winding mechanism 3, or twisting mechanism 1 according to the twist transmission state, so that tension compensation and yarn feeding speed, winding speed, or spindle speed control can be coordinated. Under operating conditions such as speed increase, speed decrease, start-up and shutdown, change of yarn type, or change of batch, this coordinated adjustment method can reduce the twist transmission mismatch caused by inconsistent responses of various mechanisms, thereby improving the stability of the yarn 14 during operation.

[0181] This invention uses a closed-loop update module 13 to reacquire the second twist correlation signal after tension compensation, and updates the tension compensation parameters for the next control cycle based on the closed-loop residual between the compensated actual tension fluctuation value and the target tension fluctuation value. Since the hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, and speed coordination compensation coefficient can be adjusted according to the actual compensation effect, the system can adapt to changes in yarn type, yarn batch, equipment speed, environmental conditions, and mechanism status, reducing reliance on manual experience adjustments.

[0182] When this invention is applied to multi-spindle twisting equipment, each twisting station can perform twist hysteresis identification, twist attenuation analysis, and tension compensation control independently. For stations in normal operation, the original process parameters can be maintained; for stations exhibiting increased hysteresis, tension instability, or signs of impending spindle breakage, tension compensation, speed compensation, pre-deceleration, tension release, alarm, or spindle stop control can be implemented individually. This method avoids the impact of a single station's abnormality on the operation of other normal stations, thus improving the overall machine production efficiency.

[0183] In summary, the embodiments of the present invention can achieve at least the following effects: First, by analyzing the dual-point twist correlation signal, the lag in twist transmission between the twisting end and the yarn forming end, the yarn guiding end, or the winding end can be identified; second, by analyzing twist attenuation, it can be determined whether there is an increase in attenuation, phase mismatch, or decreased correlation during the twist transmission process; third, by using tension adaptive compensation, tension fluctuations and twist deviations can be reduced; fourth, by using closed-loop updating compensation parameters, the adaptability to different yarn varieties, batches, and operating conditions can be improved; and fifth, by using multi-spindle independent compensation, the tension consistency and yarn forming consistency among multiple spindles can be improved, and the risk of yarn breakage can be reduced.

[0184] VIII. Specific Application Examples and Comparative Examples

[0185] Application Examples

[0186] This application example uses a multi-spindle twisting device as the application object to illustrate the specific application process of the present invention. The multi-spindle twisting device includes a twisting mechanism 1, a yarn feeding mechanism 2, a winding mechanism 3, a tension execution mechanism 4, a first detection unit 5, a second detection unit 6, and a processor or controller 15. The mechanisms cooperate sequentially according to the running path of the yarn 14 to complete the feeding, twisting, tension adjustment, and winding of the yarn 14.

[0187] In this application embodiment, the yarn 14 to be processed can be polyester filament, cotton yarn, blended yarn, or other yarns that require twisting. The twisting equipment operates according to preset process parameters, which may include spindle speed, yarn feeding speed, winding speed, target tension value, target twist range, and control cycle. The first detection unit 5 is located at the twisting end and is used to collect spindle speed pulse signals, twisting disc rotation speed signals, or yarn rotation photoelectric pulse signals at the twisting end, and uses them as the first twist-related signal. The second detection unit 6 is located at the yarn guiding end or winding end and is used to collect winding end tension signals, yarn guiding end tension signals, yarn vibration signals, or loop radius change signals, and uses them as the second twist-related signal.

[0188] During equipment operation, the processor or controller 15 acquires the first twist-related signal and the second twist-related signal in each control cycle. The signal synchronization processing module 7 performs timestamp synchronization, outlier removal, filtering, and amplitude normalization on the two types of signals to reduce the impact of acquisition time base deviation, mechanical vibration interference, sensor noise, and signal amplitude differences between different detection positions on the subsequent judgment results.

[0189] After completing the synchronization preprocessing, the twist hysteresis identification module 8 sets multiple candidate offset times within a preset sliding time window and calculates the correlation between the first twist correlation signal and the second twist correlation signal at different candidate offset times. The candidate offset time corresponding to the maximum correlation is determined as the twist hysteresis amount of the current control cycle. When the maximum correlation is lower than a preset confidence threshold, the processor or controller 15 can extend the sliding time window or call the twist hysteresis amount of the previous control cycle as the initial constraint value of the current control cycle.

[0190] Subsequently, the twist attenuation analysis module 9 determines the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first and second twist-related signals. For example, the amplitude attenuation degree can be determined based on the amplitude change ratio of the second twist-related signal relative to the first twist-related signal, the energy attenuation degree can be determined based on the energy change ratio of the two types of signals within the sliding time window, the phase deviation can be determined based on the phase difference between the two types of signals, and the correlation coefficient can be used to determine the degree of correlation between the twisting end input state and the subsequent yarn segment response state.

[0191] The twist transmission status determination module 10 determines the twist transmission status of the current twisting station based on the twist hysteresis, twist attenuation status, phase deviation, signal correlation coefficient, and tension fluctuation index. When the twist hysteresis is within the target hysteresis range, the twist attenuation coefficient is within the target attenuation range, and the tension fluctuation index does not exceed the preset fluctuation threshold, the station is determined to be in a normal transmission state. When the twist hysteresis increases for multiple consecutive control cycles, or when the twist hysteresis exceeds the preset hysteresis threshold, the station is determined to be in a hysteresis increase state. When the twist attenuation coefficient is lower than the preset attenuation threshold, or the signal correlation coefficient decreases, the station is determined to be in a twist attenuation increase state or a phase mismatch state.

[0192] When a twisting station is in a state of increasing lag, the tension compensation control module 11 determines a first compensation component based on the lag deviation of the twist lag amount relative to the target lag amount and a preset lag compensation coefficient. When a twisting station is in a state of increasing twist attenuation, the tension compensation control module 11 determines a second compensation component based on the twist attenuation coefficient and a preset attenuation compensation coefficient. When a twisting station is in a state of tension instability, the tension compensation control module 11 determines a third compensation component based on the tension fluctuation index and a preset tension fluctuation compensation coefficient. The tension compensation control module 11 determines the adjustment direction and adjustment range of the tension compensation amount based on at least one of the above compensation components.

[0193] In one specific implementation, the tension compensation amount can be determined jointly based on the twist hysteresis deviation, twist attenuation deviation, and tension fluctuation deviation. To eliminate the dimensional differences between different parameters and improve the stability and comparability of the compensation calculation, each deviation parameter can first be normalized.

[0194] Specifically, let τ be the hysteresis of the current control cycle and τ0 be the target hysteresis. Then the normalized hysteresis deviation eτ can be expressed as: eτ=(τ-τ0) / τ0.

[0195] Let α be the twist attenuation coefficient of the current control cycle and α0 be the target attenuation coefficient. Then the normalized attenuation deviation eα can be expressed as: eα=(α0-α) / α0.

[0196] Let β be the tension fluctuation index of the current control cycle and β0 be the target tension fluctuation index. Then the normalized tension fluctuation deviation eβ can be expressed as: eβ=(β-β0) / β0.

[0197] Among them, eτ, eα and eβ are dimensionless parameters, which are used to characterize the degree of deviation of the current twist hysteresis state, twist decay state and tension fluctuation state from the target state, respectively.

[0198] The tension compensation control module 11 determines the first compensation component, the second compensation component, and the third compensation component based on the normalized hysteresis deviation eτ, the normalized attenuation deviation eα, and the normalized tension fluctuation deviation eβ, respectively. The first compensation component can be expressed as k1·eτ, the second compensation component as k2·eα, and the third compensation component as k3·eβ; k1 is the hysteresis compensation weight coefficient, k2 is the attenuation compensation weight coefficient, and k3 is the tension fluctuation compensation weight coefficient. Preferably, k1, k2, and k3 are all dimensionless parameters.

[0199] In one implementation, the tension compensation amount ΔF can be determined according to the following relationship: ΔF=Lim[F0·(k1·eτ+k2·eα+k3·eβ)].

[0200] Wherein, F0 is the reference tension value, preferably the target tension value or the rated operating tension value; Lim represents the limiting processing function, which is used to limit the tension compensation amount ΔF within the preset allowable compensation range, so as to avoid the yarn 14 being subjected to excessive instantaneous impact due to the sudden change in the output of the tension actuator 4.

[0201] As can be seen from the above relationship, each compensation component within the parentheses is a dimensionless quantity. After being scaled by the reference tension value F0, the tension compensation quantity ΔF with the tension dimension is obtained, thus ensuring the consistency of dimensions in the compensation calculation process.

[0202] The positive and negative directions of the tension compensation amount ΔF can be determined by comprehensively considering the deviation of the tension signal relative to the target tension value, the sign of the normalized hysteresis deviation eτ, and the magnitude of the normalized attenuation deviation eα. When ΔF is positive, it indicates an increase in tension compensation; when ΔF is negative, it indicates a decrease in tension compensation.

[0203] In another embodiment, the tension compensation control module 11 can also select one or more compensation components to participate in the calculation based on the current twist transmission state. For example, when the current twisting position is in a state of increasing lag, the tension compensation amount can be mainly determined based on the first compensation component k1·eτ; when the current twisting position is in a state of increasing twist attenuation, the tension compensation amount can be jointly determined based on the first compensation component k1·eτ and the second compensation component k2·eα; when the current twisting position is in a state of tension instability, the tension compensation amount can be jointly determined based on the first compensation component k1·eτ, the second compensation component k2·eα, and the third compensation component k3·eβ. Thus, the tension compensation amount can be matched with the specific twist transmission state, improving the targeting and stability of the compensation control.

[0204] Furthermore, the closed-loop update module 13 can also adaptively adjust k1, k2, and k3 based on the compensated closed-loop residual. When the closed-loop residual continues to increase, the corresponding weight coefficient is increased; when the closed-loop residual continues to decrease, the corresponding weight coefficient is decreased, so as to improve the adaptability of the control system to different yarn types, operating speeds, and process conditions.

[0205] It should be noted that the above calculation method is only an exemplary implementation. In practical applications, the tension compensation amount can also be determined by weighted summation, piecewise function control, lookup table control, fuzzy control, adaptive control, or model predictive control. As long as the adjustment direction and adjustment range of the tension compensation amount can be determined based on the twist hysteresis state, twist attenuation state, and tension fluctuation state, they all fall within the protection scope of this invention.

[0206] The control output module 12 outputs the tension compensation amount to the tension actuator 4 at the corresponding workstation, so that the tension actuator 4 adjusts the running tension of the yarn 14. If the twist transmission state is a state of increased twist attenuation or phase mismatch, the control output module 12 can also output the speed compensation amount or speed change slope compensation amount to the yarn feeding mechanism 2, the winding mechanism 3 or the twisting mechanism 1, so that the tension compensation is coordinated with the adjustment of the yarn feeding speed, winding speed or spindle speed.

[0207] After tension compensation is completed, the second detection unit 6 acquires the second twist correlation signal again. The closed-loop update module 13 calculates the closed-loop residual between the compensated actual tension fluctuation value and the target tension fluctuation value based on the compensated second twist correlation signal. When the closed-loop residual is less than a preset residual threshold, the current tension compensation parameters are maintained; when the closed-loop residual is greater than or equal to the preset residual threshold, at least one of the hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, and speed coordination compensation coefficient is updated based on the closed-loop residual for use in the next control cycle.

[0208] In a specific operation, if the twisting lag at station N continuously increases during the acceleration phase, and the tension fluctuation index exceeds a preset fluctuation threshold, the processor or controller 15 determines that station N is in a tension instability state. At this time, the tension compensation control module 11 generates a tension compensation amount based on the lag deviation and tension fluctuation index of station N. The control output module 12 outputs this tension compensation amount to the tension actuator 4 at station N, and can selectively reduce the winding speed change slope or spindle speed change slope at station N. Other stations in normal operation continue to run according to the original set process parameters.

[0209] In another specific operation, if the twisting hysteresis of a certain station exceeds a preset hysteresis threshold, the signal correlation coefficient is lower than a preset correlation threshold, and the second twisting-related signal experiences a sudden drop or rise, the processor or controller 15 determines that the station is in a state of impending spindle breakage. The control output module 12 performs pre-deceleration control on the station and controls the tension actuator 4 to release or reduce tension; if the second twisting-related signal returns to normal in subsequent control cycles, the closed-loop update module 13 updates the compensation parameters according to the closed-loop residual; if the second twisting-related signal remains abnormal, the control output module 12 performs alarm or spindle stop control on the station.

[0210] Through the above application process, this invention can identify the twist transmission lag and twist attenuation state between the twisting end and the yarn guide end or winding end during the operation of the twisting equipment, and perform coordinated compensation of tension and speed according to different twist transmission states. This method helps to reduce tension fluctuations, improve twist uniformity, reduce the risk of yarn breakage, and improve the yarn consistency between different stations in multi-spindle twisting equipment.

[0211] Comparative Example 1

[0212] Comparative Example 1 uses a conventional fixed tension control method for yarn twisting. Specifically, the twisting equipment includes a twisting mechanism, a yarn feeding mechanism, a winding mechanism, and a tension actuator. The equipment operates according to preset spindle speed, yarn feeding speed, winding speed, and target tension value. The tension actuator outputs fixed tension parameters to maintain constant or approximately constant tension during yarn operation.

[0213] Under this control mode, after the equipment starts, the twisting mechanism applies twist to the yarn at a preset spindle speed, the yarn feeding mechanism feeds the yarn to the twisting area at a preset yarn feeding speed, and the winding mechanism winds the twisted yarn at a preset winding speed. The tension actuator maintains a fixed output according to the preset tension parameters, and does not detect the twist transmission status between the twisting end and the yarn guiding end, the yarn forming end, or the winding end, nor does it calculate the twist hysteresis, twist attenuation status, phase deviation, or signal correlation coefficient.

[0214] In Comparative Example 1, if the yarn type, yarn batch, operating speed, or external environment changes, the yarn's elasticity, frictional properties, and torsional transmission characteristics may change accordingly. In this case, the twist generated at the twisting end may experience response delay, attenuation, or phase mismatch during its transmission to subsequent yarn segments. However, because this method relies solely on fixed process parameters and fixed tension output, it cannot identify the dynamic changes between the input state at the twisting end and the response states at the yarn forming end, yarn guiding end, or winding end.

[0215] For example, during the acceleration phase, the input cycle of the twisting mechanism changes, while the yarn's twist response may lag behind the input change at the twisting end. Comparative Example 1 cannot compensate the tension actuator based on the twist lag, nor can it adjust the feed speed, winding speed, or spindle speed change slope based on the twist decay state. Therefore, when the twist transmission lag increases or tension fluctuations intensify, problems such as untimely compensation, expanded tension fluctuations, unstable winding conditions, or uneven twist can easily occur.

[0216] For example, when changing yarn varieties or batches, the elasticity and frictional properties of the yarn itself change, and the original fixed tension parameters may no longer be suitable for the new yarn condition. If the original tension parameters are continued to be used, the tension may be too high or too low. When the tension is too high, the yarn is prone to excessive elongation, wear, or even breakage; when the tension is too low, the yarn's running stability decreases, and it is prone to air pocket fluctuations, poor winding, or twist fluctuations.

[0217] It is evident that although the control method of Comparative Example 1 is simple, it does not identify the twist correlation between the twisting end and the subsequent yarn segment, nor does it adaptively compensate for the lag and attenuation of twist transmission. Therefore, during speed increase or decrease, batch change, variety change, or multi-spindle operation, it is difficult to adapt to changes in yarn condition and equipment operating condition in a timely manner, which can easily lead to tension fluctuations, uneven twist, increased risk of yarn breakage, and decreased consistency of multi-spindle yarn production.

[0218] Comparative Example 2

[0219] Comparative Example 2 employs a single-point tension closed-loop control method for yarn twisting. Specifically, the yarn twisting equipment includes a twisting mechanism, a yarn feeding mechanism, a winding mechanism, a tension actuator, and a tension sensor located at the yarn guide end or the winding end. During equipment operation, the tension sensor collects the yarn tension signal at a single detection location, and the controller adjusts the output of the tension actuator based on the deviation between this tension signal and the target tension value.

[0220] Under this control method, when the detected yarn tension is higher than the target tension value, the controller controls the tension actuator to reduce the tension output; when the detected yarn tension is lower than the target tension value, the controller controls the tension actuator to increase the tension output. Therefore, Comparative Example 2 can correct local tension deviations to a certain extent, reducing tension fluctuations compared to the fixed tension control method.

[0221] However, Comparative Example 2 only uses a single-point tension signal from the yarn guide end or winding end for closed-loop control. It does not acquire the first twist correlation signal from the twisting end to characterize the twist input state, nor does it match the input state of the twisting end with the response states of the yarn forming end, yarn guide end, or winding end within a time window. Therefore, this control method cannot determine the response delay between the twisting end and the subsequent yarn segment, nor can it obtain the twist hysteresis.

[0222] Meanwhile, Comparative Example 2 only adjusts based on tension deviation and cannot determine the twist attenuation state based on the amplitude ratio, energy ratio, phase difference, or correlation coefficient between the first and second twist correlation signals. When amplitude attenuation, energy attenuation, phase deviation, or reduced correlation occur during the twist transmission process, the single-point tension signal may only reflect local force changes, making it difficult to accurately determine whether the change is caused by twist transmission lag, twist attenuation, phase mismatch, or changes in winding traction.

[0223] For example, during the speed increase process, the spindle speed change at the twisting end has already occurred, but the tension response at the yarn guide end or winding end may be delayed. Comparative Example 2 only begins adjusting the tension actuator after a significant deviation in the single-point tension signal, resulting in a certain lag in the compensation action. If attenuation or phase mismatch exists simultaneously in the twist transmission at this time, simply increasing or decreasing the output of the tension actuator may not restore the match between the input state at the twisting end and the response state of the subsequent yarn segment, and may even lead to overcompensation or reverse compensation.

[0224] For example, after changing the yarn variety or batch, the elasticity, frictional properties, and torsional transmission characteristics of the yarn change. Although Comparative Example 2 can detect tension deviations, it cannot identify the changes in twist transmission status behind these deviations, nor can it update compensation parameters based on twist hysteresis, twist attenuation coefficient, or phase deviation. Therefore, under new yarn conditions, the system may still experience problems such as unstable tension regulation, large twist fluctuations, or long process stabilization times.

[0225] Furthermore, in the pre-breakage stage, the second twist correlation signal may experience sudden drops, sudden increases, or a decrease in correlation with the input state at the twisting end. Comparative Example 2, lacking correlation analysis between the twisting end and subsequent yarn segments, makes it difficult to promptly determine whether the anomaly is a pre-breakage sign, and also makes it difficult to implement pre-speed reduction, tension release, or single-spindle stop control in advance. Therefore, even when the anomaly develops rapidly, the problem of untimely breakage identification may still occur.

[0226] Therefore, it is evident that Comparative Example 2 represents a certain improvement over the fixed tension control method. However, its control basis remains limited to tension deviation at a single detection location. It cannot identify the lag, attenuation, or phase mismatch in twist transmission between the twisting end and the yarn forming end, yarn guiding end, or winding end. Nor can it adaptively update the tension compensation amount, speed compensation amount, or compensation parameters based on the twist transmission status. Consequently, under conditions such as speed increases / decreases, product changes, batch changes, multi-spindle operation, or identification of yarn breakage precursors, problems such as untimely tension compensation, inaccurate compensation direction, mismatched compensation amplitude, and insufficient yarn consistency still exist.

[0227] Effect Comparison

[0228] To illustrate the technical effects of the embodiments of the present invention, twisting tests were conducted under the same yarn type, environmental conditions, spindle speed range, and test time, using the fixed tension control method of Comparative Example 1, the single-point tension closed-loop control method of Comparative Example 2, and the twist tension adaptive compensation control method based on twist hysteresis identification of the embodiments of the present invention. During the tests, the tension fluctuation amplitude, twist variation coefficient, number of yarn breaks per unit time, process stabilization time after speed increase, and tension consistency deviation of multiple spindles were recorded under each control method.

[0229] Among them, tension fluctuation amplitude is used to characterize the degree of tension fluctuation relative to the target tension value during yarn operation; twist variation coefficient is used to characterize the uniformity of yarn twist; number of yarn breaks per unit time is used to characterize the stability of yarn operation; process stabilization time after speed increase is used to characterize the time required for the equipment to recover stable operation after speed change; multi-spindle tension consistency deviation is used to characterize the tension consistency between different stations in multi-spindle twisting equipment.

[0230] In one example test, the test results are shown in the table below:

[0231] It should be noted that the above test results were obtained under exemplary test conditions and are used to illustrate the technical effects that the embodiments of the present invention can achieve compared with the fixed tension control method and the single-point tension closed-loop control method. They are not intended to limit the scope of protection of the present invention. Different yarn types, equipment models, spindle speed ranges, environmental conditions, sampling cycles, control parameters, and test times may lead to differences in specific test values. Those skilled in the art can adjust the test parameters and evaluation indicators according to actual production conditions. As long as the dual-point twist correlation signal analysis, twist hysteresis identification, twist attenuation analysis, and tension adaptive compensation control described in the embodiments of the present invention are used, tension fluctuations, twist uniformity, breakage risk, or multi-spindle consistency can be improved to varying degrees.

[0232] The test results above show that, compared with Comparative Example 1, the embodiment of the present invention can significantly reduce the tension fluctuation amplitude, twist variation coefficient, number of yarn breaks per unit time, and tension consistency deviation of multiple spindles, and can shorten the process stabilization time after speed increase. This is because Comparative Example 1 only operates according to fixed tension parameters and cannot identify the twist transmission lag and attenuation changes between the twisting end and the yarn forming end, yarn guiding end, or winding end; while the embodiment of the present invention, through time window matching and attenuation analysis of the first twist correlation signal and the second twist correlation signal, can obtain the twist lag and twist attenuation state, and accordingly perform adaptive compensation for the tension actuator 4.

[0233] Compared to Comparative Example 2, the embodiments of the present invention also exhibit better tension control and yarn stability. While Comparative Example 2 can perform closed-loop adjustment of the tension actuator based on the deviation between a single-point tension signal and the target tension value, this method cannot identify response delays, amplitude attenuation, phase deviations, or correlation changes between the input state at the twisting end and the response state of subsequent yarn segments. Therefore, during speed increases, batch changes, variety changes, or multi-spindle operation, Comparative Example 2 may still suffer from problems such as compensation lag, inaccurate compensation direction, or mismatched compensation amplitude.

[0234] This invention, through the construction of a twist transmission state vector including twist hysteresis, twist attenuation coefficient, phase deviation, signal correlation coefficient, and tension fluctuation index, can distinguish between normal transmission state, increased hysteresis state, increased twist attenuation state, phase mismatch state, tension instability state, and pre-breakage state. For different states, the system can generate tension compensation, speed compensation, or speed change slope compensation, enabling coordinated control of tension adjustment with yarn feeding, winding, or twisting processes.

[0235] Regarding the process stabilization time after speed increase, the embodiments of the present invention can adjust the tension compensation amount in a timely manner according to the twist hysteresis and phase deviation, and can selectively reduce the slope of spindle speed change, yarn feed speed change, or winding speed change, so that the input state at the twisting end and the response state of the subsequent yarn segment gradually recover their match. Therefore, compared with the fixed tension control method and the single-point tension closed-loop control method, the embodiments of the present invention can enter the stable operating state more quickly.

[0236] Regarding multi-spindle tension consistency, embodiments of the present invention can separately identify twist lag and perform tension compensation control at different twisting stations. When a station experiences increased lag, tension instability, or signs of impending yarn breakage, the system can perform compensation or protection control only on that station, while other normal stations continue to operate according to their original process parameters. This independent compensation method for each spindle can reduce the impact of abnormalities at a single station on the overall machine operation and improve tension consistency and yarn consistency among multiple spindles.

[0237] In summary, the embodiments of the present invention can effectively solve the problems of existing twist tension control methods, such as difficulty in timely identification of twist transmission lag and attenuation, inaccurate tension compensation, and insufficient twist uniformity. It has the technical effects of reducing tension fluctuations, improving twist uniformity, reducing yarn breakage, shortening process stabilization time, and improving the consistency of multi-spindle yarn production.

[0238] In summary, this embodiment of the invention acquires a first twist-related signal at the twisting end and a second twist-related signal at the yarn forming end, yarn guiding end, or winding end. It then performs synchronous processing, time window matching, and attenuation analysis on these two types of signals to determine the twist lag, twist attenuation state, and twist transmission state. Based on this, it generates tension compensation or speed compensation, achieving adaptive compensation control of the twisted yarn tension. This scheme can reflect the dynamic changes in twist transmission from the twisting end to subsequent yarn segments, improving upon existing control methods that suffer from untimely compensation, inaccurate compensation direction, and mismatched compensation amplitude. This helps reduce tension fluctuations, improve twist uniformity, reduce the risk of yarn breakage, and enhance the yarn consistency of multi-spindle twisting equipment.

[0239] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the substance of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0240] Where there is no conflict, the technical features in the various embodiments of the present invention can be combined with each other, and the resulting technical solutions should all fall within the protection scope of the present invention. The specific structures, control flows, parameter settings, judgment thresholds, and application scenarios described in this specification are merely illustrative examples provided to facilitate understanding of the present invention and do not constitute a limitation on the specific implementation of the present invention.

[0241] It should be understood that the structural relationships and process steps shown in the accompanying drawings are merely illustrative and do not limit the actual installation positions, connection methods, module divisions, or execution sequences of the components. For those skilled in the art, without departing from the concept of this invention, the setting method of the detection unit, the signal processing method, the compensation parameter update method, and the control output method can be adaptively adjusted according to the actual equipment structure, process requirements, control system type, or yarn type.

[0242] Therefore, any modifications, equivalent substitutions, improvements, combinations, or variations made within the spirit and principles of this invention should be included within the scope of protection of this invention. The scope of protection of this invention shall be determined by the scope defined in the claims.

Claims

1. A twist tension adaptive compensation control method based on twist hysteresis identification, applied to a twisting device having a twisting mechanism, a tension execution mechanism, a yarn feeding mechanism, and a winding mechanism, characterized in that, Includes the following steps: Acquire the first twist correlation signal at the twisting end. The first twist correlation signal is used to characterize the input rhythm, input intensity, or input fluctuation state of the twisting mechanism applying twist to the yarn. Acquire a second twist correlation signal at the yarn forming end, yarn guiding end, or winding end. The second twist correlation signal is used to characterize the response rhythm, response intensity, or response fluctuation state after the twisted warp yarn is transmitted. The first twist-related signal and the second twist-related signal, which are within the same control cycle, are synchronously preprocessed. Within a preset sliding time window, time window matching is performed on the first twist-related signal and the second twist-related signal after synchronous preprocessing to determine the response delay between them, and the response delay is used as the twist hysteresis. The twist attenuation state is determined based on at least two of the following parameters: amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first twist correlation signal and the second twist correlation signal; The twist transmission status of the current twisting station is determined based on the twist hysteresis and the twist attenuation status. Based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index, the adjustment direction and adjustment range of the tension compensation amount are determined, and the tension compensation amount is output to the tension actuator. After tension compensation, the second twist correlation signal is acquired again, the closed-loop residual between the actual tension fluctuation value after compensation and the target tension fluctuation value is calculated, and the tension compensation parameters for the next control cycle are updated according to the closed-loop residual.

2. The adaptive compensation control method for twist tension based on twist hysteresis identification according to claim 1, characterized in that, The first twisting-related signal includes at least one of the following: spindle speed pulse signal, twisting disc rotation speed signal, yarn rotation photoelectric pulse signal at the twisting end, and tension signal at the twisting end; The second twist-related signal includes at least one of the following: winding end tension signal, yarn guide end tension signal, yarn vibration signal, air ring radius change signal, winding speed signal, and yarn twist detection signal.

3. The adaptive compensation control method for twist tension based on twist hysteresis identification according to claim 1, characterized in that, The synchronization preprocessing includes timestamp synchronization, outlier removal, filtering, and amplitude normalization. The timestamp synchronization is used to eliminate the data acquisition time base deviation between the detection position at the twisting end and the detection positions at the yarn forming end, yarn guiding end, or winding end. The amplitude normalization process is used to bring the first twist-correlated signal and the second twist-correlated signal to the same signal comparison scale.

4. The adaptive compensation control method for twist tension based on twist hysteresis identification according to claim 1, characterized in that, The twist hysteresis is determined as follows: Multiple candidate offset times are set within the preset sliding time window; Calculate the correlation between the first twist correlation signal and the second twist correlation signal at each candidate offset time; The candidate offset time corresponding to the maximum correlation is determined as the twist hysteresis of the current control cycle; When the maximum correlation is lower than the preset confidence threshold, the preset sliding time window is extended, or the twist hysteresis of the previous control cycle is used as the initial constraint value for the current control cycle.

5. The adaptive compensation control method for twist tension based on twist hysteresis identification according to claim 1, characterized in that, The twist attenuation state is determined by constructing a twist transmission state vector, which includes twist hysteresis, twist attenuation coefficient, phase deviation, signal correlation coefficient, and tension fluctuation index. The twist attenuation coefficient is determined based on the ratio of the change in amplitude of the second twist-related signal relative to the amplitude of the first twist-related signal, and / or based on the ratio of the change in energy of the second twist-related signal relative to the energy of the first twist-related signal. The phase deviation is determined based on the phase difference between the first twist-related signal and the second twist-related signal within the preset sliding time window; The signal correlation coefficient is determined based on the correlation between the first twist-correlation signal and the second twist-correlation signal within the preset sliding time window; The tension fluctuation index is determined based on the standard deviation, peak-to-peak value, or coefficient of variation of the tension signal within a preset time window. When the twist attenuation coefficient is lower than a preset attenuation threshold, and / or the phase deviation exceeds a preset phase threshold, and / or the signal correlation coefficient is lower than a preset correlation threshold, it is determined that there is a trend of increased twist attenuation or phase mismatch in the current control cycle.

6. The adaptive compensation control method for twist tension based on twist hysteresis identification according to claim 5, characterized in that, The twist transmission state includes at least one of the following: normal transmission state, hysteresis increase state, twist attenuation increase state, phase mismatch state, tension instability state, and pre-breakage state. When the twisting hysteresis increases for several consecutive control cycles and the tension fluctuation index exceeds the preset fluctuation threshold, it is determined that the current twisting station is in a state of tension instability. When the twisting hysteresis exceeds a preset hysteresis threshold, the signal correlation coefficient is lower than a preset correlation threshold, and the second twisting correlation signal shows a sudden drop or rise, it is determined that the current twisting station is in a state of impending thread breakage.

7. The adaptive compensation control method for twist tension based on twist hysteresis identification according to claim 1, characterized in that, The step of determining the adjustment direction and adjustment range of the tension compensation amount based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index includes: When the twist transmission state is in a state of increased hysteresis, the first compensation component is determined based on the product of the hysteresis deviation and the preset hysteresis compensation coefficient. When the twist transmission state is a state of increased twist attenuation, the second compensation component is determined based on the product of the twist attenuation coefficient and the preset attenuation compensation coefficient. When the twist transmission state is a tension instability state, the third compensation component is determined according to the product of the tension fluctuation index and the preset tension fluctuation compensation coefficient. The adjustment range of the tension compensation amount is determined based on at least one of the first compensation component, the second compensation component, and the third compensation component; The adjustment direction of the tension compensation amount is determined based on the sign of the hysteresis deviation, the deviation of the twist attenuation coefficient from the target attenuation coefficient, and the deviation of the tension signal from the target tension value.

8. The adaptive compensation control method for twist tension based on twist hysteresis identification according to claim 1, characterized in that, The tension compensation parameters include hysteresis compensation coefficient, attenuation compensation coefficient, tension fluctuation compensation coefficient, and velocity coordination compensation coefficient; The step of updating the tension compensation parameters for the next control cycle based on the closed-loop residual includes: When the closed-loop residual is less than the preset residual threshold, the current tension compensation parameters are maintained; When the closed-loop residual is greater than or equal to the preset residual threshold, at least one of the hysteresis compensation coefficient, the attenuation compensation coefficient, the tension fluctuation compensation coefficient, and the speed coordination compensation coefficient is updated based on the closed-loop residual. The speed coordination compensation coefficient is used to determine the speed compensation amount or speed change slope compensation amount of the yarn feeding mechanism, winding mechanism or twisting mechanism when the twist transmission state is in a phase mismatch state or a twist attenuation increase state.

9. A twist tension adaptive compensation control system based on twist hysteresis identification, applied to twisting equipment, characterized in that, include: Twisting mechanism, used to apply twist to yarn; A yarn feeding mechanism is used to feed yarn to the twisting mechanism; A winding mechanism is used to wind twisted yarn; Tension actuators are used to adjust the tension of yarn during its operation. The first detection unit is located at the twisting end and is used to acquire the first twist correlation signal. The first twist correlation signal is used to characterize the input rhythm, input intensity or input fluctuation state of the twisting mechanism applying twist to the yarn. The second detection unit is located at the yarn forming end, yarn guiding end, or winding end, and is used to acquire the second twist correlation signal. The second twist correlation signal is used to characterize the response rhythm, response intensity, or response fluctuation state after the twisted warp yarn is transmitted. The processor or controller is communicatively connected to the first detection unit, the second detection unit, the tension actuator, the yarn feeding mechanism, the winding mechanism, and the twisting mechanism, respectively. The processor or controller includes: The signal synchronization processing module is used to perform timestamp synchronization, outlier removal, filtering, and amplitude normalization on the first twist-correlation signal and the second twist-correlation signal. The twist hysteresis identification module is used to perform time window matching on the first twist association signal and the second twist association signal after synchronous preprocessing within a preset sliding time window, determine the response delay between the two, and use the response delay as the twist hysteresis amount; The twist attenuation analysis module is used to determine the twist attenuation state based on at least two parameters among the amplitude ratio, energy ratio, phase difference, and correlation coefficient between the first twist correlation signal and the second twist correlation signal. The twisting transmission status determination module is used to determine the twisting transmission status of the current twisting station based on the twisting hysteresis and the twisting attenuation status. The tension compensation control module is used to determine the adjustment direction and adjustment range of the tension compensation amount based on the twist transmission state, the hysteresis deviation of the twist hysteresis amount relative to the target hysteresis amount, and the tension fluctuation index. The control output module is used to output the tension compensation amount to the tension actuator, and output the speed compensation amount or speed change slope compensation amount to the yarn feeding mechanism, the winding mechanism or the twisting mechanism according to the twist transmission state. The closed-loop update module is used to update the tension compensation parameters for the next control cycle based on the closed-loop residual between the actual tension fluctuation value after compensation and the target tension fluctuation value.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor or controller, it implements the twist tension adaptive compensation control method based on twist hysteresis identification as described in any one of claims 1 to 8.

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