Untwisting speed adjusting method for vortex spinning yarn twist test

Abstract

The invention relates to the technical field of spinning yarn untwisting speed regulation, and particularly discloses an untwisting speed regulation method for vortex spinning yarn twist test, which comprises the following steps: additionally arranging a current sampling module in a motor background system of an untwisting motor, and monitoring the working current of the untwisting motor at the current moment in the spinning yarn untwisting process in real time; determining a first predicted tension of the spinning yarn of the target specification at the current moment; the method comprises the following steps of: monitoring swinging parameters of a free swinging yarn guide hook in each swinging period in real time through the free swinging yarn guide hook mounted on a spinning yarn untwisting path; comprehensively calculating a second predicted tension of the spinning yarn of the target specification at the current moment; and finally, the predicted tension of the target specification spinning yarn at the current moment is comprehensively determined, the untwisting speed of the target specification spinning yarn at the current moment is correspondingly adjusted based on the predicted tension, and by monitoring and adjusting the yarn tension in real time, the product quality and the production efficiency can be improved, the service life of equipment can be prolonged, and the cost can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of untwisting speed regulation of spinning yarns, and relates to an untwisting speed regulation method for testing the twist of eddy current spinning yarns. Background Art

[0002] The untwisting process of spinning yarn is directly related to the tension control of the yarn, and the stability of the yarn tension is one of the key factors to ensure the quality of spinning. If the untwisting speed is not dynamically adjusted according to the real-time changes in the yarn tension, the yarn tension may be too high or too low, which may cause a series of problems. When the tension is too high, the yarn is prone to breakage, affecting production continuity and increasing the breakage rate; when the tension is too low, the yarn may relax, resulting in uneven spinning or insufficient yarn strength, which ultimately affects product quality. In addition, the fluctuation of yarn tension may also cause mechanical shock to the equipment, increase equipment wear and shorten the service life of the equipment.

[0003] However, the current technology generally relies on tension sensors to obtain the tension at each time point in the yarn untwisting process when adjusting the untwisting speed, so as to adjust the untwisting speed. This method has obvious technical defects and disadvantages. First, the tension sensor is expensive, especially in scenarios where high-precision measurement is required, the cost of the sensor often accounts for a large proportion of the overall cost of the equipment. This increases the economic pressure of equipment investment for spinning companies, especially small and medium-sized enterprises. Secondly, the tension sensor often has the defect of being easily damaged during actual use. The spinning production environment is complex, and factors such as friction, vibration and dust will be generated during the high-speed movement of the yarn, which will have an adverse effect on the stability and service life of the sensor, resulting in frequent damage or misalignment of the sensor, thereby affecting the accuracy of the tension measurement. In addition, the installation and maintenance of the tension sensor are also relatively complicated, and regular calibration is required to ensure the measurement accuracy, which further increases the maintenance cost and workload. During the untwisting process, if the tension sensor fails or the measurement error occurs, the system may not be able to adjust the speed in time, causing the yarn tension to be out of control, affecting the production quality and efficiency. More importantly, the measurement range of the tension sensor is limited. When processing yarns of different specifications, the sensor may need to be replaced or adjusted. It lacks adaptability and flexibility and is difficult to meet diverse production needs. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention provides a method for adjusting the untwisting speed for vortex spinning yarn twist testing, which is used to solve the above technical problems.

[0005] In order to achieve the above purpose and other purposes, the technical solution adopted by the present invention is as follows: The present invention provides a method for adjusting the untwisting speed for testing the twist of vortex spinning yarns, the method comprising the following steps: By adding a current sampling module to the motor background system of the untwisting motor, the working current of the untwisting motor in the untwisting spinning line at the current moment is monitored in real time; based on the working current of the untwisting motor in the untwisting spinning line at the current moment, the first predicted tension of the spinning line of the target specification at the current moment is determined; By installing a free swinging yarn guide hook on the untwisting path of the spinning line, the swing parameters of the spinning line in each swing cycle are monitored in real time; based on the swing parameters, the second predicted tension of the spinning line of the target specification at the current moment is comprehensively calculated; Combined with the first predicted tension and the second predicted tension of the target specification yarn at the current moment, the predicted tension of the target specification yarn at the current moment is comprehensively determined, and based on the predicted tension, the untwisting speed of the target specification yarn at the current moment is correspondingly adjusted.

[0006] Determine the first predicted tension of the spinning line of target specification at the current moment, including: The dynamic no-load reference current of the untwisting motor is obtained by looking up the table, and the working current of the untwisting motor at the current moment in the untwisting spinning yarn is calculated by difference with the dynamic no-load reference current of the untwisting motor to obtain the net effective current A0 of the untwisting motor at the current moment in the untwisting spinning yarn; Obtaining the motor torque-tension conversion coefficient γ of the experimentally calibrated untwisting motor; Calculate the fiber arrangement correction factor ε and fiber arrangement deviation coefficient △α of the target specification spinning line; The cumulative rotation angle Zj of the untwisting motor in the untwisting spinning line up to the current moment is collected, and finally the first predicted tension of the target specification spinning line at the current moment is calculated. , e is a natural constant, and β is a preset friction attenuation coefficient.

[0007] The fiber arrangement correction factor ε and fiber arrangement deviation coefficient △α of the target specification spinning line are calculated. The calculation process includes: The initial cross-sectional image of the target yarn is converted into a grayscale image, the edge detection algorithm is applied to extract the fiber edge of the target yarn, and the Hough transform is used to detect the line to obtain the direction vector component of each fiber of the target yarn. , i is the number of each fiber, and then the angle between each fiber and the yarn axis corresponding to the target specification spinning line is calculated ; Calculate the standard deviation of the fiber and yarn axis corresponding to the target specification spinning line according to the statistical formula , and then use the calculation formula , and obtain the initial reference fiber orientation degree Qx1 of the target specification spinning line; During the untwisting process, a real-time imaging device is used to collect a real-time image of the target specification spinning line, edge detection and direction extraction are performed on the fibers in the real-time image of the target specification spinning line, and the fiber orientation degree Qx0 of the target specification spinning line at the current moment is calculated; The fiber arrangement correction factor of the target specification yarn is calculated from this and fiber arrangement deviation coefficient , where C is the set proportional constant.

[0008] Calculate the second predicted tension of the spinning line of target specification at the current moment, including: The swing parameters of the yarn guide hook in each swing cycle include effective swing length and maximum swing angle; Obtain the swing start time point and end time point of each swing cycle, thereby forming a swing time period of each swing cycle, compare the current moment with the swing time period of each swing cycle, obtain the swing cycle to which the current moment belongs, and then obtain the swing parameters of the swing cycle to which the current moment belongs; Using analytical formula ; Calculate the second predicted tension η2 of the target specification spinning line at the current moment In the above formula, m and g represent the equivalent mass and gravity acceleration of the yarn guide hook respectively, and L represents the effective pendulum length of the swing cycle at the current moment. is the maximum swing angle of the swing cycle at the current moment, tp is the average time of a single swing cycle, MJ is the windward area of ​​the yarn guide hook, ρ is the air density, tc is the air resistance coefficient, κ is the set working condition compensation factor, μ represents the friction coefficient between the target specification spinning line and the yarn guide hook stored in the database, and υ is the tangential speed of the yarn guide hook.

[0009] The predicted tension of the target yarn at the current moment is determined by: The first predicted tension of the target specification spinning line at the past 9 moments is collected, and it is summarized with the first predicted tension of the target specification spinning line at the current moment. The variance of the first predicted tension of the target specification spinning line at 10 moments is calculated to obtain the tension prediction variance of the target specification spinning line corresponding to the current method. ; The second predicted tension of the target specification spinning line at the past 9 moments is collected, and it is summarized with the second predicted tension of the target specification spinning line at the current moment. The variance of the second predicted tension of the target specification spinning line at 10 moments is calculated to obtain the tension prediction variance of the target specification spinning line corresponding to the swing method. ; The predicted tension of the target yarn at the current moment is determined , α1 and α2 represent the set current method confidence weight and swing method confidence weight respectively, and α1+α2=1.

[0010] ; Where η' represents the permissible tension threshold, and △η represents the set dead zone threshold.

[0011] The operating logic of the over-tension deceleration mode is: Obtain the untwisting speed φ0 of the target specification spinning yarn at the current moment; By analyzing the formula , the adjustment untwisting speed φ1 of the target specification spinning line at the next moment under the over-tension deceleration mode is analyzed, where k1, k2 and k3 represent the predefined over-tension ratio adjustment coefficient, integral adjustment coefficient and differential suppression coefficient respectively, and △t is the interval between the current moment and the next moment, is the tension deviation value of the current moment corresponding to the previous moment; The adjusted untwisting speed φ1 of the target specification spun yarn at the next moment in the over-tension deceleration mode is fed back to the untwisting motor operating system, thereby adjusting the untwisting speed of the untwisting motor corresponding to the next moment accordingly.

[0012] The operating logic of under tension acceleration mode is: By analyzing the formula , analyze the adjustment untwisting speed φ2 of the target specification spinning line at the next moment in the under-tension acceleration mode, where k4 and k5 represent the predefined under-tension compensation adjustment coefficient and the recovery rate coefficient respectively, t represents the moment from entering the current under-tension acceleration mode, that is, the current moment; τ represents the predefined time constant, which is used to control the smoothness of the acceleration process, and e is a natural constant; The adjusted untwisting speed φ2 of the target specification spun yarn at the next moment in the under-tension acceleration mode is fed back to the untwisting motor operating system, thereby adjusting the untwisting speed of the untwisting motor corresponding to the next moment accordingly.

[0013] As described above, the untwisting speed adjustment method for vortex spinning yarn twist test provided by the present invention has at least the following beneficial effects: The present invention realizes real-time monitoring and prediction of yarn tension by adding a current sampling module and a free-swinging yarn guide hook to the background system of the untwisting motor, and dynamically adjusts the untwisting speed based on this, which can greatly improve the accuracy and response speed of tension control. The current sampling module can monitor the working current of the motor in real time, thereby predicting the change of yarn tension. Combined with the swing parameters of the yarn guide hook, a more accurate tension value can be comprehensively calculated. This dual monitoring method ensures the reliability of tension prediction, helps to promptly detect and correct tension anomalies, and prevent yarn breakage or uneven quality problems; By adjusting the untwisting speed in real time, the influence of tension fluctuations during the spinning process can be effectively reduced. During the spinning process, changes in tension directly affect the uniformity and strength of the yarn. By dynamically adjusting the predicted tension, it is possible to respond quickly when the tension exceeds or falls below the set threshold and adjust the untwisting speed to restore to the ideal state. This real-time adjustment mechanism can significantly reduce the breakage rate and improve production efficiency and product quality; In addition, this method can also improve the service life of the equipment and the economic benefits of production. By accurately controlling the tension, mechanical wear and yarn waste caused by unstable tension are reduced, the service life of the equipment is extended, and maintenance costs are reduced. At the same time, a stable production process also means higher output and lower defective rate, thereby improving the overall economic benefits; In summary, real-time monitoring and adjustment of yarn tension can not only improve product quality and production efficiency, but also extend equipment life, reduce costs, and enhance the flexibility and adaptability of the production system. It is an indispensable technical means in modern spinning production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0015] Figure 1 It is a schematic diagram of the connection of each step of the method of the present invention. DETAILED DESCRIPTION

[0016] The above contents in combination with the implementation of the present invention are merely examples and explanations of the concept of the present invention. The technical personnel in the relevant technical field may make various modifications or supplements to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention. Example 1

[0017] See also Figure 1 As shown, a method for adjusting the untwisting speed for testing the twist of vortex spinning yarns comprises the following steps: By adding a current sampling module to the motor background system of the untwisting motor, the working current of the untwisting motor in the untwisting spinning line at the current moment is monitored in real time; based on the working current of the untwisting motor in the untwisting spinning line at the current moment, the first predicted tension of the spinning line of the target specification at the current moment is determined; Determine the first predicted tension of the spinning line of target specification at the current moment, including: The dynamic no-load reference current of the untwisting motor is obtained by looking up the table, and the working current of the untwisting motor at the current moment in the untwisting spinning yarn is calculated by difference with the dynamic no-load reference current of the untwisting motor to obtain the net effective current A0 of the untwisting motor at the current moment in the untwisting spinning yarn; Obtaining the motor torque-tension conversion coefficient γ of the experimentally calibrated untwisting motor; Calculate the fiber arrangement correction factor ε and fiber arrangement deviation coefficient △α of the target specification spinning line; The cumulative rotation angle Zj of the untwisting motor in the untwisting spinning line up to the current moment is collected, and finally the first predicted tension of the target specification spinning line at the current moment is calculated. , e is a natural constant, and β is a preset friction attenuation coefficient.

[0018] The underlying logic of the above calculation formula is to combine motor control theory with the mechanical properties of textile materials to predict the tension of yarns in the textile production process in a dynamic and real-time manner. The design of this formula fully considers multiple factors, including the current output of the motor, the loss of the mechanical system, the arrangement of the fibers, and the friction effect. By combining these parameters, it can more accurately reflect the tension changes of the yarns under actual working conditions. The numerator of the formula represents the net effective current. This term is introduced to eliminate the influence of mechanical loss on the current. In practical applications, the current performance of the motor under no-load and load conditions is different. Traditional methods usually use a fixed no-load current value, which will cause errors in the low-speed area. By establishing a dynamic no-load reference curve, the real current of the motor at different speeds can be captured more accurately, thereby improving the accuracy of tension prediction; The denominator is the correction to the system gain. Here, γ is the conversion coefficient between motor torque and tension, while ε and △α reflect the effect of changes in fiber arrangement on torque transmission efficiency. The arrangement of fibers directly affects the strength and tension of the yarn. Therefore, by introducing these correction factors, we can better adapt to the nonlinear characteristics of fiber materials and ensure that the calculation of tension is still accurate under different fiber orientations. Finally, the exponential term is used to compensate for the tension attenuation caused by friction and energy dissipation. Friction is inevitable in the textile process, and it will gradually accumulate over time, resulting in a decrease in tension. By integrating the instantaneous angular velocity of the motor, the cumulative mechanical angle can be obtained, which reflects the accumulation of friction effects. The introduction of this compensation mechanism allows the formula to maintain a high prediction accuracy after long-term operation; this calculation method can effectively reduce hardware costs because it does not rely on additional sensors, but instead performs real-time monitoring and calculations through the existing motor control system.

[0019] At the same time, each parameter in the above formula has its own clear physical unit. The unit of the final output η1 is cN (centinewton), which is a unit of tension. The net effective current A0 of the untwisting motor in the untwisting spinning yarn at the current moment is A (ampere), and the conversion coefficient γ of the motor torque and tension in the denominator is A / cN (ampere / centinewton), and 1+ε×△α is a dimensionless correction factor, so the unit of the entire denominator is A / cN; the unit of the pre-set friction attenuation coefficient β in the exponential part is (per second), and the unit of the cumulative rotation angle Zj of the untwisting motor in the untwisting spinning line up to the current moment is rad (radian). In the exponential function, radian as the unit of angle can be regarded as dimensionless, because β×Zj is a dimensionless quantity and the exponential term has no unit; so the unit of the whole formula is cN (centinewon).

[0020] The physical meaning of tension refers to the tensile force generated in the yarn or material. The formula reflects the direct relationship between the motor output and the yarn tension by calculating the effective current (eliminating the influence of the no-load current) and combining the conversion relationship between the motor torque and tension. By considering the influence of factors such as friction and fiber arrangement, the formula can more comprehensively describe the tension changes under actual working conditions.

[0021] It should be added that the calculation process of the motor torque-tension conversion coefficient γ of the untwisting motor is as follows: Connect the untwisting motor to the load, record the current and corresponding tension of the untwisting motor under different load conditions, and calculate the current change and tension change under different load conditions: For example: The current change from 0cN to 100cN is ; The tension changes to ; The motor torque-tension conversion coefficient of the untwisting motor is calculated using the calculation formula .

[0022] The fiber arrangement correction factor ε and fiber arrangement deviation coefficient △α of the target specification spinning line are calculated. The calculation process includes: The initial cross-sectional image of the target yarn is converted into a grayscale image, the edge detection algorithm is applied to extract the fiber edge of the target yarn, and the Hough transform is used to detect the line to obtain the direction vector component of each fiber of the target yarn. , i is the number of each fiber, and then the angle between each fiber and the yarn axis corresponding to the target specification spinning line is calculated ; Calculate the standard deviation of the fiber and yarn axis corresponding to the target specification spinning line according to the statistical formula , and then use the calculation formula , and obtain the initial reference fiber orientation degree Qx1 of the target specification spinning line; During the untwisting process, a real-time imaging device is used to collect a real-time image of the target specification spinning line, edge detection and direction extraction are performed on the fibers in the real-time image of the target specification spinning line, and the fiber orientation degree Qx0 of the target specification spinning line at the current moment is calculated; The fiber arrangement correction factor of the target specification yarn is calculated from this and fiber arrangement deviation coefficient , where C is the set proportional constant.

[0023] By installing a free swinging yarn guide hook on the untwisting path of the spinning line, the swing parameters of the spinning line in each swing cycle are monitored in real time; based on the swing parameters, the second predicted tension of the spinning line of the target specification at the current moment is comprehensively calculated; Calculate the second predicted tension of the spinning line of target specification at the current moment, including: The swing parameters of the yarn guide hook in each swing cycle include effective swing length and maximum swing angle; The effective pendulum length is the vertical distance from the rotation fulcrum of the swinging yarn guide hook to the yarn contact point. In this problem, the effective pendulum length represents the hanging length of the yarn guide hook, which affects the swing period and the calculation of the yarn tension. The effective pendulum length is usually determined by measuring the vertical distance from the fulcrum to the yarn contact point; The maximum swing angle is the maximum angle that the guide hook can reach during the swing process. In this context, the maximum swing angle is an important parameter for calculating the yarn tension.

[0024] Obtain the swing start time point and end time point of each swing cycle, thereby forming a swing time period of each swing cycle, compare the current moment with the swing time period of each swing cycle, obtain the swing cycle to which the current moment belongs, and then obtain the swing parameters of the swing cycle to which the current moment belongs; Using analytical formula , calculate the second predicted tension η2 of the spinning line of target specification at the current moment; In the above formula, m and g represent the equivalent mass and gravitational acceleration of the yarn guide hook respectively; the equivalent mass unit of the yarn guide hook is kilogram (kg). The influence of mass is that the larger the mass, the more significant the inertia effect, which will affect the stability of the swing and the calculation of the final tension; the unit of gravitational acceleration is meter per second squared (m / s²). Gravitational acceleration is the reason for the yarn guide hook to sag, and it is also a factor that must be considered in calculating tension; L represents the effective pendulum length of the current swing cycle, in meters (m). The effective pendulum length is the vertical distance from the rotation fulcrum to the yarn contact point of the yarn guide hook, which affects the calculation of the swing amplitude and tension; The maximum swing angle of the swing cycle at the current moment; the unit is radians (rad). The square of the swing angle plays an important role in the correction term, affecting the calculation of air resistance and the final tension result; tp is the average time of a single pendulum cycle, where the single pendulum cycle is calculated by measuring the time it takes to complete 10 full swings with a stopwatch (tp = total time / 10); the unit is seconds (s). The square of the period is used as the denominator in the formula and affects the overall calculation result. The shorter the period, the greater the tension value may be; MJ is the windward area of ​​the yarn guide hook; the unit is square meters (m²). The windward area affects the size of the air resistance and directly affects the resistance correction of the swing; ρ is the air density, which is obtained by looking up the table based on the temperature and humidity of the workshop; the unit is kilograms per cubic meter (kg / m³). The air density is multiplied by the windward area of ​​the yarn guide hook and the air resistance coefficient, which plays a key role in the air resistance correction term; tc is the air resistance coefficient, which is calculated by looking up the table according to the shape of the yarn guide hook: 1.2 for a cylinder and 0.6 for a streamlined shape; it has no unit. The air resistance coefficient describes the effect of the shape of the yarn guide hook on air resistance and is an important parameter in the air resistance correction term; κ is the set working condition compensation factor, which is 0.12 for ordinary workshops and 0.18 for high humidity environments; it has no unit. The working condition compensation factor is an empirical parameter that takes into account the correction item under specific working conditions and affects the calculation result of the final tension; μ represents the friction coefficient between the target specification spinning yarn and the yarn guide hook stored in the database, and has no unit. The friction coefficient describes the degree of friction between the yarn and the yarn guide hook, and affects the calculation of the friction loss compensation item; υ is the tangential speed of the yarn guide hook, measured in meters per second (m / s). The linear speed of the yarn affects the calculation of the friction loss compensation term. The greater the speed, the more significant the friction loss may be. It is taken from the encoder signal of the untwisting motor (needs to be converted to the tangential speed of the yarn guide hook: υ=ω·L); the symbol ω represents the angular velocity, usually in radians per second (rad / s), and the angular velocity ω is used to calculate the tangential speed υ of the yarn guide hook. The tangential speed refers to the speed of an object at a point on its path of motion, perpendicular to the direction of the path. Here, the tangential speed υ of the yarn guide hook can be obtained by multiplying the angular velocity ω by the effective pendulum length L of the yarn guide hook.

[0025] The calculation formula for the second predicted tension η2 of the target specification spinning line at the current moment combines the principle of simple pendulum motion, air resistance correction term and friction loss compensation term, which can more comprehensively consider the factors affecting the yarn tension. By considering multiple parameters such as swing amplitude, swing length, swing cycle and yarn linear speed, the formula can provide more accurate tension prediction results. This method of comprehensively considering various influencing factors helps to improve the accuracy and reliability of tension prediction, thereby helping the spinning production process to be more stable and controllable; Secondly, using this calculation formula to predict tension is real-time and convenient. At the spinning production site, it is necessary to understand the tension of the yarn in a timely manner so as to adjust the production parameters in time and ensure product quality. Through real-time measurement and calculation, the changes in yarn tension can be dynamically monitored during the spinning process, problems can be discovered and adjusted in time, and production quality problems caused by abnormal tension can be avoided; In addition, this calculation method is cost-effective and practical compared to traditional tension sensors. Traditional tension sensors require additional equipment and maintenance costs, while using the formula to calculate tension can save equipment costs, reduce maintenance work, and improve production efficiency. At the same time, this method can also reduce failure rates, reduce production interruptions, and improve the stability and continuity of the production line.

[0026] Combined with the first predicted tension and the second predicted tension of the target specification yarn at the current moment, the predicted tension of the target specification yarn at the current moment is comprehensively determined, and based on the predicted tension, the untwisting speed of the target specification yarn at the current moment is correspondingly adjusted.

[0027] The predicted tension of the target yarn at the current moment is determined by: The first predicted tension of the target specification spinning line at the past 9 moments is collected, and it is summarized with the first predicted tension of the target specification spinning line at the current moment. The variance of the first predicted tension of the target specification spinning line at 10 moments is calculated to obtain the tension prediction variance of the target specification spinning line corresponding to the current method. ; The second predicted tension of the target specification spinning line at the past 9 moments is collected, and it is summarized with the second predicted tension of the target specification spinning line at the current moment. The variance of the second predicted tension of the target specification spinning line at 10 moments is calculated to obtain the tension prediction variance of the target specification spinning line corresponding to the swing method. ; The predicted tension of the target yarn at the current moment is determined , α1 and α2 represent the set current method confidence weight and swing method confidence weight respectively, and α1+α2=1.

[0028] ; Wherein η' represents the permissible tension threshold; △η represents the set dead zone threshold, which is the set tension deviation range. Tension changes within this range are regarded as normal fluctuations and do not trigger speed adjustment to avoid frequent adjustments.

[0029] In the spinning production process, the stability of yarn tension is directly related to the quality and production efficiency of the product. By setting the tension threshold and adjusting the speed in three situations (deceleration for over-tension, acceleration for under-tension, and maintaining the current speed), the yarn tension can be effectively and accurately controlled. In the spinning process, tension fluctuations may cause yarn breakage, uneven spinning, or product defects. By timely adjusting the tension beyond the threshold range, the tension fluctuation can be controlled within a reasonable range to avoid yarn breakage due to excessive tension, or yarn relaxation and quality degradation due to too low tension. At the same time, setting a dead zone can avoid frequent speed adjustments due to small tension fluctuations, which not only reduces the wear of the mechanical system, but also avoids unnecessary disturbances caused by frequent switching of the control system, thereby improving the operating life and stability of the equipment.

[0030] The operating logic of the over-tension deceleration mode is: Obtain the untwisting speed φ0 of the target specification spinning yarn at the current moment; By analyzing the formula , analyze the adjustment untwisting speed φ1 of the target specification spinning line at the next moment under the over-tension deceleration mode, where k1, k2 and k3 represent the predefined over-tension ratio adjustment coefficient, integral adjustment coefficient and differential suppression coefficient respectively, and △t is the interval between the current moment and the next moment, which is set to 1min; is the tension deviation value of the current moment corresponding to the previous moment, which is obtained by subtracting the permissible tension threshold from the tension value of the previous moment; The adjusted untwisting speed φ1 of the target specification spun yarn at the next moment in the over-tension deceleration mode is fed back to the untwisting motor operating system, thereby adjusting the untwisting speed of the untwisting motor corresponding to the next moment accordingly.

[0031] In the control system, especially in the tension control of the spinning untwisting process, accurate adjustment of the untwisting speed is crucial to ensure the yarn quality. By using the above calculation formula, the untwisting speed can be accurately adjusted: The proportional term of the above calculation formula is designed in the form of a nonlinear function. By introducing the proportional term of the tension deviation in the form of 1.5, the system can respond more sensitively to smaller deviations and handle larger deviations more gently. This nonlinear adjustment method can effectively prevent system instability caused by over-adjustment, especially when the tension changes drastically, it can smoothly transition and reduce the impact on the mechanical system; Secondly, the introduction of the integral term is discretized to express the integral term as the product of the current tension deviation and the sampling time. This approximation method not only simplifies the calculation, but also retains the core function of integral control, that is, the correction of cumulative errors. Through the cumulative effect of the integral term, long-term steady-state errors can be effectively eliminated, ensuring that the system can still maintain the set tension range after long-term operation. This is crucial to maintaining product consistency and quality stability during the spinning process; The differential term is digitized by backward difference, providing real-time feedback on the rate of change of tension. The existence of the differential term enables the system to predict the trend of tension changes in advance, so as to make pre-adjustments to prevent system oscillations caused by sudden changes. This predictive adjustment is particularly important in high-speed spinning because it can reduce yarn breakage or quality defects caused by tension fluctuations.

[0032] The operating logic of under tension acceleration mode is: By analyzing the formula , analyze the adjustment untwisting speed φ2 of the target specification spinning line at the next moment in the under-tension acceleration mode, where k4 and k5 represent the predefined under-tension compensation adjustment coefficient and the recovery rate coefficient respectively, t represents the moment from entering the current under-tension acceleration mode, that is, the current moment; τ represents the predefined time constant, which is used to control the smoothness of the acceleration process, and e is a natural constant; The above calculation formula is used to dynamically adjust the untwisting speed according to the tension deviation, which has significant benefits and technical necessity, especially in the regulation under undertension (insufficient tension). The tanh (hyperbolic tangent) function of the nonlinear adjustment term in the formula is a smooth nonlinear function with a range between [-1,1]. Compared with linear regulation, the introduction of the tanh function can significantly improve the robustness and stability of the system. When the tension deviation is small, the tanh function is close to linear, and can respond quickly and adjust the untwisting speed appropriately. This sensitivity is particularly important for fine-tuning when the tension deviation is small, avoiding system oscillation or instability caused by over-regulation. When the tension deviation is large, the tanh function tends to saturation (approaching 1 or -1), thereby limiting the adjustment range. This saturation characteristic can effectively prevent over-regulation caused by excessive deviation, protect the mechanical system from severe shock, and avoid problems such as yarn breakage. The curve nature of the tanh function determines that the adjustment process is continuous and smooth, which can avoid mutations in the adjustment process. This is very important in the dynamic control of high-speed spinning, because a sudden change in speed may cause a momentary imbalance in yarn tension and affect the yarn quality.

[0033] The time constant term in the formula introduces a time dynamic adjustment process, and the progressiveness of speed adjustment is achieved through an exponential function. At the beginning of the adjustment, the change in the untwisting speed is large, which can quickly respond to the tension deviation; as time goes by, the adjustment amplitude gradually decreases and eventually stabilizes. This design avoids system instability caused by too fast adjustment, while ensuring the smoothness of the adjustment. By adjusting the time constant τ, the speed of the adjustment process can be controlled. For example, for high-speed spinning processes, a smaller τ value can be selected to speed up the adjustment speed; while for processes with low speed or high precision requirements, a larger τ value can be selected to achieve smoother adjustment. The design of this item can gradually increase the untwisting speed when the tension is insufficient, compensating for the yarn quality problems caused by under-tension. For example, when the yarn tension suddenly drops, this item will quickly increase the speed adjustment amount, and reduce the adjustment amplitude as the tension gradually recovers, thereby achieving dynamic balance.

[0034] The k4 and k5 in the formula control the weights of the nonlinear adjustment term and the time constant term respectively. By adjusting these two parameters, optimization can be performed for different yarn materials, specifications and production process requirements. For example: for thinner yarns (such as cotton yarn), since their tension fluctuations are more sensitive, a larger k4 value can be selected to enhance the responsiveness to tension deviations; for thicker yarns (such as chemical fibers), a larger k5 value can be selected to enhance the dynamic recovery ability of the time constant term, thereby coping with larger tension fluctuations.

[0035] The adjusted untwisting speed φ2 of the target specification spun yarn at the next moment in the under-tension acceleration mode is fed back to the untwisting motor operating system, thereby adjusting the untwisting speed of the untwisting motor corresponding to the next moment accordingly.

[0036] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0037] It should be understood that determining B based on A does not mean determining B only based on A. B can also be determined based on A and / or other information.

[0038] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0039] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for adjusting the untwisting speed for testing the twist of vortex spinning yarn, characterized in that: include: By adding a current sampling module to the motor background system of the untwisting motor, the working current of the untwisting motor at the current moment in the untwisting spinning yarn can be monitored in real time; Determine a first predicted tension of the target specification spinning line at the current moment based on the working current of the untwisting motor in the untwisting spinning line at the current moment; By installing a free swinging yarn guide hook on the untwisting path of the spinning line, the swing parameters of the spinning line in each swing cycle are monitored in real time; based on the swing parameters, the second predicted tension of the spinning line of the target specification at the current moment is comprehensively calculated; Combined with the first predicted tension and the second predicted tension of the target specification yarn at the current moment, the predicted tension of the target specification yarn at the current moment is comprehensively determined, and based on the predicted tension, the untwisting speed of the target specification yarn at the current moment is correspondingly adjusted.

2. The method for adjusting the untwisting speed for testing the twist of vortex spinning yarn according to claim 1, characterized in that: Determine the first predicted tension of the spinning line of target specification at the current moment, including: The dynamic no-load reference current of the untwisting motor is obtained by looking up the table, and the working current of the untwisting motor at the current moment in the untwisting spinning yarn is calculated by difference with the dynamic no-load reference current of the untwisting motor to obtain the net effective current A0 of the untwisting motor at the current moment in the untwisting spinning yarn; Obtaining the motor torque-tension conversion coefficient γ of the experimentally calibrated untwisting motor; Calculate the fiber arrangement correction factor ε and fiber arrangement deviation coefficient △α of the target specification spinning line; The cumulative rotation angle Zj of the untwisting motor in the untwisting spinning line up to the current moment is collected, and finally the first predicted tension of the target specification spinning line at the current moment is calculated. , e is a natural constant, and β is a preset friction attenuation coefficient.

3. The method for adjusting the untwisting speed for testing the twist of vortex spinning yarn according to claim 2, characterized in that: The fiber arrangement correction factor ε and fiber arrangement deviation coefficient △α of the target specification spinning line are calculated. The calculation process includes: The initial cross-sectional image of the target yarn is converted into a grayscale image, the edge detection algorithm is applied to extract the fiber edge of the target yarn, and the Hough transform is used to detect the line to obtain the direction vector component of each fiber of the target yarn. , i is the number of each fiber, and then the angle between each fiber and the yarn axis corresponding to the target specification spinning line is calculated ; Calculate the standard deviation of the fiber and yarn axis corresponding to the target specification spinning line according to the statistical formula , and then use the calculation formula , and obtain the initial reference fiber orientation degree Qx1 of the target specification spinning line; During the untwisting process, a real-time imaging device is used to collect a real-time image of the target specification spinning line, edge detection and direction extraction are performed on the fibers in the real-time image of the target specification spinning line, and the fiber orientation degree Qx0 of the target specification spinning line at the current moment is calculated; The fiber arrangement correction factor of the target specification yarn is calculated from this and fiber arrangement deviation coefficient , where C is the set proportional constant.

4. The method for adjusting the untwisting speed for testing the twist of vortex spinning yarn according to claim 1, characterized in that: Calculate the second predicted tension of the spinning line of target specification at the current moment, including: The swing parameters of the yarn guide hook in each swing cycle include effective swing length and maximum swing angle; Obtain the swing start time point and end time point of each swing cycle, thereby forming a swing time period of each swing cycle, compare the current moment with the swing time period of each swing cycle, obtain the swing cycle to which the current moment belongs, and then obtain the swing parameters of the swing cycle to which the current moment belongs; Using analytical formula ; Calculate the second predicted tension η2 of the target specification spinning line at the current moment In the above formula, m and g represent the equivalent mass and gravity acceleration of the yarn guide hook respectively, and L represents the effective pendulum length of the swing cycle at the current moment. is the maximum swing angle of the swing cycle at the current moment, tp is the average time of a single swing cycle, MJ is the windward area of ​​the yarn guide hook, ρ is the air density, tc is the air resistance coefficient, κ is the set working condition compensation factor, μ represents the friction coefficient between the target specification spinning line and the yarn guide hook stored in the database, and υ is the tangential speed of the yarn guide hook.

5. The method for adjusting the untwisting speed for testing the twist of vortex spinning yarn according to claim 1, characterized in that: The predicted tension of the target yarn at the current moment is determined by: The first predicted tension of the target specification spinning line at the past 9 moments is collected, and it is summarized with the first predicted tension of the target specification spinning line at the current moment. The variance of the first predicted tension of the target specification spinning line at 10 moments is calculated to obtain the tension prediction variance of the target specification spinning line corresponding to the current method. ; The second predicted tension of the target specification spinning line at the past 9 moments is collected, and it is summarized with the second predicted tension of the target specification spinning line at the current moment. The variance of the second predicted tension of the target specification spinning line at 10 moments is calculated to obtain the tension prediction variance of the target specification spinning line corresponding to the swing method. ; The predicted tension of the target yarn at the current moment is determined , α1 and α2 represent the set current method confidence weight and swing method confidence weight respectively, and α1+α2=1.

6. The method for adjusting the untwisting speed for testing the twist of vortex spinning yarn according to claim 1, characterized in that: ； Where η' represents the permissible tension threshold, and △η represents the set dead zone threshold.

7. The method for adjusting the untwisting speed for testing the twist of vortex spinning yarn according to claim 6, characterized in that: The operating logic of the over-tension deceleration mode is: Obtain the untwisting speed φ0 of the target specification spinning yarn at the current moment; By analyzing the formula , the adjustment untwisting speed φ1 of the target specification spinning line at the next moment under the over-tension deceleration mode is analyzed, where k1, k2 and k3 represent the predefined over-tension ratio adjustment coefficient, integral adjustment coefficient and differential suppression coefficient respectively, and △t is the interval between the current moment and the next moment, is the tension deviation value of the current moment corresponding to the previous moment; The adjusted untwisting speed φ1 of the target specification spun yarn at the next moment in the over-tension deceleration mode is fed back to the untwisting motor operating system, thereby adjusting the untwisting speed of the untwisting motor corresponding to the next moment accordingly.

8. The method for adjusting the untwisting speed for testing the twist of vortex spinning yarn according to claim 6, characterized in that: The operating logic of under tension acceleration mode is: By analyzing the formula , analyze the adjustment untwisting speed φ2 of the target specification spinning line at the next moment in the under-tension acceleration mode, where k4 and k5 represent the predefined under-tension compensation adjustment coefficient and the recovery rate coefficient respectively, t represents the moment from entering the current under-tension acceleration mode, that is, the current moment; τ represents the predefined time constant, which is used to control the smoothness of the acceleration process, and e is a natural constant; The adjusted untwisting speed φ2 of the target specification spun yarn at the next moment in the under-tension acceleration mode is fed back to the untwisting motor operating system, thereby adjusting the untwisting speed of the untwisting motor corresponding to the next moment accordingly.

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