Polyester staple fiber tension detection control method and system

Abstract

The invention provides a polyester staple fiber tension detection control method and system, and relates to the technical field of polyester staple fiber production. The method comprises the following steps: setting a first preset speed and speed regulation coefficients of rollers in a front process and a subsequent process of a treatment process; determining the speeds of the rollers in each previous process and each subsequent process; determining the rotating speeds of the rollers in the treatment procedure, the front procedure and the subsequent procedure; the actually measured tension of the polyester staple fibers between the rollers is detected; determining whether the rotating speed needs to be adjusted; if adjustment is needed, a tension control equation is obtained; obtaining an updated speed adjustment coefficient; and determining the updated rotating speed. According to the invention, whether the rotating speed needs to be adjusted can be determined based on the speed adjustment coefficient of the rollers and the actually measured tension of the polyester staple fibers between the rollers, so that the updated speed adjustment coefficient is obtained, the rotating speed of the rollers is updated, and the accuracy of determining the updated rotating speed is improved; and the tension control efficiency and stability in the polyester staple fiber production process are improved.

Description

Technical Field

[0001] This invention relates to the field of polyester staple fiber production technology, and in particular to a method and system for detecting and controlling the tension of polyester staple fiber. Background Technology

[0002] In the production process of polyester staple fiber, the tension of the fibers directly affects the forming quality, uniformity, and mechanical properties of the fibers as they are transferred between multiple rollers. Timely adjustment of the tension between the polyester staple fibers is necessary to improve the production quality. According to relevant technologies, roller speed is typically adjusted using a fixed speed ratio or simple PID control. However, this approach suffers from inaccurate tension control and low production efficiency. It is difficult to adjust the roller speed based on the tension of the polyester staple fibers between different processes, thus hindering the control of fiber tension and resulting in poor production stability and overall poor quality.

[0003] The information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] This invention provides a method for detecting and controlling the tension of polyester staple fiber, which can solve the technical problem that it is difficult to adjust the speed of the roller according to the tension of polyester staple fiber between different processes, thereby controlling the tension of polyester staple fiber.

[0005] According to a first aspect of the present invention, a method for detecting and controlling the tension of polyester staple fibers is provided, comprising: In the production process of polyester staple fiber, the first preset speed of the first roller of the tension heat setter is set, and the speed adjustment coefficients of the rollers of the pre-process and subsequent processes of the tension heat setter are set. Based on the first preset speed and the speed adjustment coefficient, determine the speed of the rollers in each pre-process of the tension heat setting machine and the speed of the rollers in the subsequent process. Based on the first preset speed, the speed of the rollers, and the design parameters of the tension heat setter, the preceding process, and the following process, the processing steps of the tension heat setter, and the rotational speeds of the rollers in the preceding and following processes are determined. The actual tension of the polyester staple fiber between the rollers is detected by tension sensors installed between the rollers. Based on the measured tension and the set tension between each roller, determine whether the rotational speed of each roller needs to be adjusted; If adjustment is required, obtain the tension control equations between each roller; Based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation, the updated speed adjustment coefficient is obtained; Based on the updated speed, determine the update speed of the rollers for each process.

[0006] According to the present invention, the measured tension of polyester staple fibers in each process includes: A bundle of polyester staple fibers is placed on one side of the roller of the tension sensor, and a thrust is applied to the roller. The plane of the polyester staple fiber bundle is parallel to the radial section of the roller, and the direction of the thrust is parallel to the radial section of the roller. Determine the start and end positions of the contact section between the polyester staple fiber harness and the roller of the tension sensor; Determine the first angle between the direction of the line connecting any point on the portion of the polyester staple fiber bundle before the roller of the contact tension sensor and the starting position and the horizontal direction, and determine the second angle between the direction of the line connecting any point on the portion of the polyester staple fiber bundle after the roller of the contact tension sensor and the ending position and the horizontal direction. The force exerted by the roller on the pressure probe in the horizontal direction is obtained; The measured tension is determined based on the applied force, the first included angle, and the second included angle.

[0007] According to the present invention, determining the measured tension includes: According to the formula Determine the measured tension T, where, For the force described, The second included angle, This is the first included angle.

[0008] According to the present invention, the method further includes: According to the formula The equation to be fitted is obtained for the tension control equation between the i-th roller and the (i+1)-th roller, where, Let i be the speed of the (i+1)th roller. Let be the speed of the i-th roller. Let be the length of the polyester staple fiber bundle between the i-th roller and the (i+1)-th roller. Let k be the speed of the kth roller. The speed of the (k+1)th roller, , and Let be the coefficients to be fitted for the i-th roller. Let be the residual corresponding to the i-th roller, and if be a conditional function, k ≤ i-1, where k and i are both positive integers; Based on the speed and measured tension of each roller during multiple tests, the fitting coefficients of the tension control equation between the i-th roller and the (i+1)-th roller are solved to obtain the solution values ​​of the fitting coefficients. Based on the solved values ​​of the coefficients to be fitted and the equation to be fitted for the tension control equation between the i-th roller and the (i+1)-th roller, the tension control equation between the i-th roller and the (i+1)-th roller is obtained.

[0009] According to the present invention, determining whether the rotational speed of each roller needs to be adjusted includes: Determine the relative error between the measured tension and the set tension; If the relative error is greater than or equal to the preset error threshold, then the rotational speed of each roller needs to be adjusted.

[0010] According to the present invention, obtaining the updated speed adjustment coefficient includes: Based on the first preset speed, set tension, measured tension, speed adjustment coefficient, and tension control equation, determine the speed update constraint conditions; Based on the set tension, determine the velocity update objective function; Based on the speed update constraints and the speed update objective function, the updated speed adjustment coefficient is obtained.

[0011] According to the present invention, determining the velocity update constraint includes: According to the formula Obtain the velocity update constraints, where, The updated predicted tension between the i-th roller and the (i+1)-th roller. The measured tension between the i-th roller and the (i+1)-th roller. Set the tension between the i-th roller and the (i+1)-th roller. To preset the error threshold, This represents the speed adjustment amount for the (i+1)th roller. The speed adjustment amount for the i-th roller is... Let be the updated speed of the (k+1)th roller. Let be the updated speed of the k-th roller. Let k be the current speed of the k-th roller. Let be the current speed of the (k+1)th roller. This represents the speed adjustment amount for the (k+1)th roller. This represents the speed adjustment amount for the k-th roller. The speed adjustment amount for the first roller of the tension heat setter. Let be the current speed of the i-th roller. Let be the current speed of the (i+1)th roller. Let be the updated speed of the (i+1)th roller. Let be the updated speed adjustment coefficient for the i-th roller. Let be the updated speed adjustment coefficient for the k-th roller. Let be the updated speed of the i-th roller. This is the lower limit of the speed of the i-th roller. This represents the upper limit of the speed of the i-th roller. This is the lower limit of the speed of the (i+1)th roller. This represents the upper limit of the speed of the (i+1)th roller. This is the lower limit of the speed of the k-th roller. This represents the upper limit of the speed of the k-th roller. This is the lower limit of the speed of the (k+1)th roller. This represents the upper limit of the speed of the (k+1)th roller. for The solution value, for The solution value, for The solution value.

[0012] According to the present invention, determining the velocity update objective function includes: According to the formula Determine the speed update objective function, where N is the total number of rollers in multiple processes. This is the function to be minimized.

[0013] According to a second aspect of the present invention, a polyester staple fiber tension detection and control system is provided, comprising: The setting module sets the first preset speed of the first roller of the tension heat setter during the production process of polyester staple fiber, and sets the speed adjustment coefficients of the rollers of the pre-process and subsequent processes of the tension heat setter. The speed determination module determines the speed of the rollers in each pre-process of the tension heat setting machine and the speed of the rollers in the subsequent process based on the first preset speed and the speed adjustment coefficient. The rotation speed determination module determines the rotation speed of the processing steps of the tension heat setting machine, the rotation speed of the rollers in the pre-process and the subsequent process based on the first preset speed, the speed of the rollers, and the design parameters of the tension heat setting machine, the pre-process and the subsequent process. The actual tension measurement module uses tension sensors installed between each roller to detect the actual tension of the polyester staple fiber between each roller. The judgment module determines whether the rotational speed of each roller needs to be adjusted based on the measured tension and the set tension between each roller. The tension control equation module obtains the tension control equations between each roller if adjustment is required. The speed adjustment coefficient update module obtains the updated speed adjustment coefficient based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation. Update the speed module and determine the update speed of the rollers in each process based on the updated speed.

[0014] By adopting the above technical solution, the present invention can achieve the following technical effects: According to the present invention, in the production process of polyester staple fiber, a first preset speed and speed adjustment coefficients for the rollers of the preceding and subsequent processing steps can be set to determine the rotational speed of each roller. Based on tension sensors, the measured tension of the polyester staple fiber between each roller can be detected to determine whether the rotational speed needs adjustment, obtain the tension control equation, and then obtain the updated speed adjustment coefficient to determine the updated rotational speed of the roller. The roller speed can be adjusted according to the tension of the polyester staple fiber in different processes, thereby controlling the tension of the polyester staple fiber, improving the accuracy of the rotational speed, enhancing the accuracy, efficiency, and stability of tension control during the polyester staple fiber production process, and improving the quality of the polyester staple fiber. Furthermore, the speed ratio between adjacent rollers can be determined through the speed adjustment coefficient, thereby determining the elongation ratio of the polyester staple fiber between the two rollers and stabilizing the elongation ratio, facilitating the control of the tension and properties of the polyester staple fiber, and contributing to the improvement of the quality of the polyester staple fiber. The system can also set a first preset speed, as well as speed adjustment coefficients for the rollers in the pre-processing and post-processing stages of the tension heat setting machine, thereby determining the rotational speed of each roller and providing basic data for determining whether the rotational speed of each roller needs adjustment. When determining the tension control equation, the system can determine the fitting equation for the tension control equation between each roller based on the speed and measured tension of each roller during multiple tests, thus determining the tension control equation between each roller. It considers the degree of elongation of the polyester staple fiber bundles in the processes preceding each roller, the length of the polyester staple fiber bundles between rollers, and the deformation of the polyester staple fiber bundles between rollers, and the relationship with the tension between rollers, improving the accuracy, objectivity, and comprehensiveness of the tension control equation determination. When determining the speed update constraints and update objective function, the system can determine whether the rotational speed of each roller needs adjustment based on the measured tension and the set tension between each roller, and if adjustment is required, determine the speed update constraints and update objective function. Considering the inherent errors in the tension control equation, the fact that adjusting the tension between one roller updates the tension between all rollers, and the risk of polyester staple fiber breakage due to large speed adjustments, multiple speed update constraints and objective functions are set to improve the accuracy, objectivity, and comprehensiveness of determining these constraints and objective functions. Furthermore, based on the speed update constraints and objective functions, the updated speed adjustment coefficient can be obtained, thereby determining the updated speed, resulting in the updated rotational speed. This updates the roller speeds for each process, controlling the tension of the polyester staple fiber between rollers. This improves the accuracy of the updated rotational speed determination and enhances the efficiency and stability of tension control during polyester staple fiber production.

[0015] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Other features and aspects of the invention will become clearer from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort. Figure 1 A schematic flowchart of a polyester staple fiber tension detection and control method according to an embodiment of the present invention is shown as an example; Figure 2 A flowchart illustrating the measured tension of polyester staple fibers between individual rollers according to an embodiment of the present invention is provided. Figure 3 An exemplary schematic diagram of the measured tension of polyester staple fiber according to an embodiment of the present invention is shown; Figure 4 A block diagram of a polyester staple fiber tension detection and control system according to an embodiment of the present invention is shown as an example. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0019] Figure 1 An exemplary flowchart of a polyester staple fiber tension detection and control method according to an embodiment of the present invention is shown, the method comprising: Step S1: In the production process of polyester staple fiber, set the first preset speed of the first roller of the tension heat setting machine, and set the speed adjustment coefficient of the rollers of the pre-process and subsequent processes of the tension heat setting machine. Step S2: Determine the speed of the rollers in each pre-process of the tension heat setting machine and the speed of the rollers in the subsequent process according to the first preset speed and speed adjustment coefficient. Step S3: Based on the first preset speed, the speed of the rollers, and the design parameters of the tension heat setting machine, the preceding process, and the following process, determine the processing steps of the tension heat setting machine, and the rotational speeds of the rollers in the preceding and following processes. Step S4: The actual tension of the polyester staple fiber between each roller is detected by tension sensors installed between each roller. Step S5: Based on the measured tension and the set tension between each roller, determine whether the rotational speed of each roller needs to be adjusted. Step S6: If adjustment is required, obtain the tension control equations between each roller. Step S7: Based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation, obtain the updated speed adjustment coefficient; Step S8: Determine the update speed of the rollers for each process based on the updated speed.

[0020] According to an embodiment of the present invention, the polyester staple fiber tension detection and control method can set a first preset speed and speed adjustment coefficients for the rollers of the preceding and subsequent processing steps during the polyester staple fiber production process, thereby determining the rotational speed of each roller. Based on a tension sensor, the measured tension of the polyester staple fiber between each roller can be detected to determine whether the rotational speed needs adjustment, obtain the tension control equation, obtain the updated speed adjustment coefficient, and determine the updated rotational speed of the roller. The roller speed can be adjusted according to the tension of the polyester staple fiber in different processes, thereby controlling the tension of the polyester staple fiber, improving the accuracy of the rotational speed, enhancing the accuracy, efficiency, and stability of tension control during the polyester staple fiber production process, and improving the quality of the polyester staple fiber.

[0021] According to an embodiment of the present invention, in step S1, during the production process of polyester staple fiber, a first preset speed of the first roller of the tension heat setting machine is set, and speed adjustment coefficients of the rollers of the pre-process and subsequent processes of the tension heat setting machine are set. During the production process of polyester staple fiber, the tension heat setting machine processes include multiple (e.g., three) tension heat setting machines, arranged in a sequential order. The roller corresponding to the first tension heat setting machine is the first roller. The drawing roller linear speed of the first roller, i.e., the first preset speed (or it can be set by the rotational speed of the first roller), can be set on the host computer and the field HMI (Human Machine Interface). The first preset speed remains constant. Furthermore, on the host computer and the field HMI, the speed adjustment coefficients of the rollers for the pre-processing steps (i.e., processes before the processing steps of the tension heat setter, such as drawing machines, yarn guides, etc.) and subsequent processes (i.e., processes after the processing steps of the tension heat setter, such as drawing machines, three-roll traction machines, and crimping machines, etc.) of the tension heat setter are set. Based on the aforementioned first preset speed and speed adjustment coefficients, the speed (linear speed) of the rollers for each pre-processing step and subsequent process of the tension heat setter can be determined. The setting of the first preset speed and the roller speed adjustment coefficients in this invention is not limited.

[0022] According to an embodiment of the present invention, in step S2, the speeds of the rollers in each preceding process of the tension heat setting machine and the speeds of the rollers in subsequent processes are determined based on a first preset speed and a speed adjustment coefficient. Each preceding process may include one or more rollers. The speed adjustment coefficient is the speed adjustment coefficient of each roller in the preceding process. In order from first to last, the product of the speed adjustment coefficient of the first roller and the speed of the first roller is equal to the speed of the second roller. The product of the speed adjustment coefficient of the second roller and the speed of the second roller is equal to the speed of the third roller, and so on. The speed of the next roller is obtained by multiplying the speed adjustment coefficient of each roller in the preceding process by the speed of the roller. In the example, if the first roller is the Xth roller in the sequence, then the speed of the (X-1)th roller multiplied by its speed adjustment coefficient equals the first preset speed. Based on this setting, the speeds of each roller in the preceding process can be calculated backwards from the first preset speed. That is, the speed of the (X-1)th roller is obtained by dividing the first preset speed by the speed adjustment coefficient of the (X-1)th roller, and so on, until the speed of the first roller is obtained by dividing the speed of the second roller by its speed adjustment coefficient. Similarly, the speed adjustment coefficient of each roller in subsequent processes is multiplied by the roller's speed to obtain the speed of the next roller. Therefore, the speed of the first roller multiplied by the speed adjustment coefficient of the Xth roller equals the speed of the (X+1)th roller in subsequent processes, and so on, until the speed of the (N-1)th roller multiplied by its speed adjustment coefficient equals the speed of the Nth roller, where N is the total number of rollers in the multiple processes.

[0023] In this way, the speed ratio between adjacent rollers can be determined by the speed adjustment coefficient, thereby determining the stretching ratio of polyester staple fiber between the two rollers and stabilizing the stretching ratio. This facilitates the control of the tension and properties of polyester staple fiber, which helps to improve the quality of polyester staple fiber.

[0024] According to an embodiment of the present invention, in step S3, the rotational speeds of the rollers in the tension heat setting machine, the preceding process, and the subsequent process are determined based on the first preset speed, the roller speed, and the design parameters of the tension heat setting machine, the preceding process, and the subsequent process. The diameters of the drafting rollers and the reduction ratios of the reducers in the tension heat setting machine, the preceding process, and the subsequent process are the design parameters. Further, the first preset speed, the roller speed, and the design parameters can be substituted into formula V. i =πD i n i / p i By performing conversions, the rotational speeds of the rollers in the tension heat setting machine's processing steps, the preceding steps, and the subsequent steps can be determined, where V i D represents the speed (m / min) of the i-th roller.i n is the diameter of the roller (m); i p is the rotational speed (r / min) of the i-th roller; i Let be the reduction ratio of the reducer for the i-th roller.

[0025] In this way, a first preset speed and the speed adjustment coefficients of the rollers in the pre-process and post-process of the tension heat setting machine can be set, thereby determining the rotational speed of each roller and providing basic data for determining whether the rotational speed of each roller needs to be adjusted.

[0026] Figure 2 A flowchart illustrating the measured tension of polyester staple fibers between individual rollers according to an embodiment of the present invention is provided.

[0027] According to an embodiment of the present invention, in step S4, the measured tension of polyester staple fiber in each process is detected by a tension sensor arranged between each process, including: step S41, placing a polyester staple fiber bundle on one side of the roller of the tension sensor and applying a pushing force to the roller, wherein the plane of the polyester staple fiber bundle is parallel to the radial section of the roller, and the direction of the pushing force is parallel to the radial section of the roller; step S42, determining the start position and end position of the contact section between the polyester staple fiber bundle and the roller of the tension sensor; step S43, determining the first angle between the direction of the line connecting any point on the portion of the polyester staple fiber bundle before contacting the roller of the tension sensor and the start position and the horizontal direction, and determining the second angle between the direction of the line connecting any point on the portion of the polyester staple fiber bundle after contacting the roller of the tension sensor and the end position and the horizontal direction; step S44, obtaining the force applied by the roller to the pressure probe in the horizontal direction; step S45, determining the measured tension based on the force, the first angle, and the second angle.

[0028] Figure 3 A schematic diagram illustrating the measured tension of polyester staple fiber according to an embodiment of the present invention is shown.

[0029] According to an embodiment of the present invention, in step S41, a bundle of polyester staple fibers is placed on one side of the roller of the tension sensor, and a thrust is applied to the roller. The plane containing the polyester staple fiber bundle is parallel to the radial cross-section of the roller, and the direction of the thrust is parallel to the radial cross-section of the roller. Placing the polyester staple fiber bundle on one side of the roller of the tension sensor (e.g., a pulley-type tension sensor) allows the polyester staple fiber to apply a thrust to the roller. The plane containing the bundle is parallel to the radial cross-section of the roller, i.e., the plane containing the bundle and the radial cross-section of the roller are on the same two-dimensional plane. Similarly, the direction of the thrust is parallel to the radial cross-section of the roller, i.e., the direction of the thrust and the radial cross-section of the roller are on the same two-dimensional plane. Therefore, the direction of the thrust is on the plane containing the polyester staple fiber bundle. By arranging the polyester staple fiber bundle and the tension sensor in this manner, the force applied by the roller to the pressure probe in the horizontal direction is on a two-dimensional plane, facilitating the calculation of the tension generated by the polyester staple fiber bundle.

[0030] According to an embodiment of the present invention, in step S42, the start and end positions of the contact section between the polyester staple fiber bundle and the roller of the tension sensor are determined. A portion of the polyester staple fiber bundle will contact the roller of the tension sensor to determine the force applied by the roller to the pressure probe in the horizontal direction. The contact portion between the polyester staple fiber bundle and the roller of the tension sensor is the contact section. The position where the polyester staple fiber bundle begins to contact the roller of the tension sensor (i.e., the inlet end) is the start position, and the position where the polyester staple fiber bundle leaves the roller of the tension sensor (i.e., the outlet end) is the end position.

[0031] According to an embodiment of the present invention, in step S43, a first angle is determined between the direction of the line connecting any point on the portion of the polyester staple fiber bundle before the roller of the contact tension sensor and the starting position, and the horizontal direction; and a second angle is determined between the direction of the line connecting any point on the portion of the polyester staple fiber bundle after the roller of the contact tension sensor and the ending position, and the horizontal direction. The angle between the direction of the line connecting the portion of the polyester staple fiber bundle before the roller of the contact tension sensor and the starting position, and the horizontal direction (i.e., the angle between the wire entry direction and the horizontal direction), is the first angle. The angle between the direction of the line connecting the portion of the polyester staple fiber bundle after the roller of the contact tension sensor and the ending position, and the horizontal direction (i.e., the angle between the wire exit direction and the horizontal direction), is the second angle.

[0032] According to an embodiment of the present invention, in step S44, the force exerted by the roller on the pressure probe in the horizontal direction is obtained. This force can be detected by a pressure sensor. The pressure probe of the pressure sensor can be mounted on the bearing of the roller, positioned horizontally, to detect the horizontal pressure.

[0033] According to an embodiment of the present invention, in step S45, determining the measured tension based on the applied force, the first included angle, and the second included angle includes: determining the measured tension T according to formula (1). (1) in, For the force described, The second included angle, This is the first included angle.

[0034] According to an embodiment of the present invention, in formula (1), The product of the measured tension and the first included angle can be considered as the horizontal component of the measured tension. This represents the product of the measured tension and the second included angle, and can also be considered as the horizontal component of the measured tension. Since these two components are in opposite directions, therefore... It can be considered as the magnitude of the resultant force of the two component forces mentioned above, that is, the force exerted by the roller on the pressure probe in the horizontal direction. Therefore, the relationship between the applied force and the measured tension can be obtained, that is, By performing an equation transformation on the above relationship, the measured tension can be determined. This measurement method converts the tension inside the wire harness into a horizontal force, facilitating measurement and improving accuracy.

[0035] According to an embodiment of the present invention, in step S5, determining whether the rotational speed of each roller needs to be adjusted based on the measured tension and the set tension between each roller includes: determining the relative error between the measured tension and the set tension; if the relative error is greater than or equal to a preset error threshold, then it is determined that the rotational speed of each roller needs to be adjusted. The tension between each roller preset by the production personnel is the set tension. Under the set tension, the production of polyester staple fiber can be more stable, and higher quality polyester staple fiber can be produced. For example, the set tension is set to 30% of the breaking strength of polyester staple fiber. The ratio of the absolute value of the difference between the measured tension and the set tension to the set tension is the relative error. Using the same method, the relative error corresponding to the measured tension between each roller can be determined. When any one of the above relative errors is greater than a preset error threshold, it can be considered that the error between the measured tension and the set tension is large, and the roller speed needs to be adjusted to control the tension between each roller. Conversely, when all relative errors are less than or equal to the preset error threshold, it can be considered that the error between the measured tension and the set tension is small, and stable production of polyester staple fiber is possible, so there is no need to adjust the roller speed. The preset error threshold is determined by the production specifications of the polyester staple fiber. For example, when producing high-strength polyester staple fiber, a smaller preset error threshold (e.g., 3%) can be set, and when producing ordinary-strength polyester staple fiber, a larger preset error threshold (e.g., 10%) can be set. This invention does not limit the set tension and the preset error threshold.

[0036] According to an embodiment of the present invention, in step S6, if adjustment is required, the tension control equations between the rollers are obtained. If the rotational speed of each roller needs to be adjusted, the tension control equations between the rollers can be retrieved from the database, wherein the tension control equations can be predetermined and stored in the database. The specific steps for determining the tension control equations are as follows.

[0037] According to an embodiment of the present invention, the method further includes: obtaining the equation to be fitted for the tension control equation between the i-th roller and the (i+1)-th roller according to formula (2). (2) in, Let i be the speed of the (i+1)th roller. Let be the speed of the i-th roller. Let be the length of the polyester staple fiber bundle between the i-th roller and the (i+1)-th roller. Let k be the speed of the kth roller. The speed of the (k+1)th roller, , and Let be the coefficients to be fitted for the i-th roller. Let be the residual corresponding to the i-th roller, and if be the conditional function, k ≤ i-1, where k and i are both positive integers. Based on the speed and measured tension of each roller during multiple tests, the coefficients to be fitted for the tension control equation between the i-th roller and the (i+1)-th roller are solved to obtain the solution values ​​of the coefficients to be fitted. Based on the solution values ​​of the coefficients to be fitted and the equation to be fitted for the tension control equation between the i-th roller and the (i+1)-th roller, the tension control equation between the i-th roller and the (i+1)-th roller is obtained.

[0038] According to an embodiment of the present invention, since the longer the polyester staple fiber bundle has been stretched, the finer the polyester staple fiber with a constant total volume, the more dispersed its internal structure, and the smaller the tension of the polyester staple fiber, the longer the polyester staple fiber bundle has been stretched before the i-th roller, the tension between the i-th roller and the (i+1)-th roller is negatively correlated. That is, the more the polyester staple fiber bundle has been stretched before the i-th roller, the smaller the tension between the i-th roller and the (i+1)-th roller. In formula (2), Represents a conditional function, when When the speed of the (k+1)th roller is greater than the speed of the kth roller, the polyester staple fiber bundle will be stretched between the kth roller and the (k+1)th roller, and the value of the conditional function is... Ideally, this value equals the speed adjustment coefficient of the k-th roller. However, in practice, errors may exist. For example, the motor driving the roller may have errors, or the reducer may have errors. Therefore, the ratio of the measured speeds should be used. To reduce the error of the tension control equation, this ratio can also be considered as the proportion of the polyester staple fiber bundle that is stretched between the k-th roller and the (k+1)-th roller. Conversely, when When the speed of the (k+1)th roller is less than or equal to the speed of the kth roller, the length of the polyester staple fiber bundle between the kth roller and the (k+1)th roller remains unchanged, and the value of the conditional function is 1. This can also be considered as the polyester staple fiber bundle not being stretched between the kth roller and the (k+1)th roller. Furthermore, This represents the product of the proportions by which the polyester staple fiber bundles are stretched between each roller before the i-th roller (i.e., from the 1st roller to the (i-1th roller). It can be considered as the proportion by which the polyester staple fiber bundle has been stretched relative to its original length when it reaches the i-th roller. The larger this proportion is, the longer the polyester staple fiber bundle has been stretched relative to its original length when it reaches the i-th roller, and the smaller the tension between the i-th roller and the (i+1th roller).

[0039] According to an embodiment of the present invention, based on Hooke's law, it can be obtained that within the elastic limit, the deformation of an object is proportional to the external force causing the deformation. Therefore, the tension between the i-th roller and the (i+1)-th roller is proportional to the deformation of the polyester staple fiber bundle between the i-th roller and the (i+1)-th roller. In formula (2), This represents the speed difference between the (i+1)th roller and the ith roller. Since the larger the speed difference, the easier it is for the polyester staple fiber to be stretched, the speed difference can be used as a value describing the deformation of the polyester staple fiber bundle between the ith roller and the (i+1)th roller. The larger this value, the greater the deformation of the polyester staple fiber bundle between the ith roller and the (i+1)th roller, and the greater the tension between the ith roller and the (i+1)th roller. Let be the length of the polyester staple fiber bundle between the i-th roller and the (i+1)-th roller. Since the shorter the polyester staple fiber bundle, the less prone it is to deformation, therefore... The elastic modulus of the polyester staple fiber used between the i-th roller and the (i+1)-th roller is a factor. A larger value indicates a longer polyester staple fiber bundle, a smaller elastic modulus, and lower tension between the i-th roller and the (i+1)-th roller (i.e., the length of the polyester staple fiber bundle between the i-th roller and the (i+1)-th roller is negatively correlated with the tension between them). Further, settings regarding... , as well as The equation to be fitted This can be used as the equation to be fitted for the tension control equation between the i-th roller and the (i+1)-th roller.

[0040] According to an embodiment of the present invention, based on the speed and measured tension of each roller during multiple tests, the fitting coefficients of the tension control equation between the i-th roller and the (i+1)-th roller are solved to obtain the solution values ​​of the fitting coefficients. In formula (2), , and Let be the coefficients to be fitted for the i-th roller, where and Dimensionless The unit is N·s (i.e., Newton-second), which allows for The result is expressed in units of N (Newtons), thus unifying the dimensions of the unfitted equation for the tension control equation between the i-th and (i+1)-th rollers. Furthermore, by using a fitting method, based on the speed and measured tension of each roller during multiple tests, the unfitted coefficients corresponding to the i-th roller can be determined. , and By performing the solution, the solution value can be obtained. Since multiple solution values ​​for the coefficients to be fitted can be obtained based on the speed and measured tension of each roller during multiple tests when solving for the coefficients to be fitted for the i-th roller, that is, solving for the residual obtained after substituting the roller speed and measured tension multiple times. The coefficients to be fitted when the sum of squares (in Newtons) is minimized are used as the solution values ​​of the coefficients to be fitted for the i-th roller.

[0041] According to an embodiment of the present invention, the tension control equation between the i-th roller and the (i+1)-th roller is obtained based on the solved values ​​of the coefficients to be fitted and the equation to be fitted for the tension control equation between the i-th roller and the (i+1)-th roller. Based on the same processing method, the tension control equation between each roller can be obtained.

[0042] In this way, based on the speed and measured tension of each roller during multiple tests, the equation to be fitted for the tension control equation between each roller can be determined, thereby establishing the tension control equation between each roller. This approach considers the degree of elongation of the polyester staple fiber bundles in the processes preceding each roller, the length of the polyester staple fiber bundles between rollers, the deformation of the polyester staple fiber bundles between rollers, and the relationship between these factors and the tension between rollers, thus improving the accuracy, objectivity, and comprehensiveness of the tension control equation determination.

[0043] According to an embodiment of the present invention, in step S7, obtaining the updated speed adjustment coefficient based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation includes: determining speed update constraints based on the first preset speed, set tension, measured tension, speed adjustment coefficient, and tension control equation; determining the speed update objective function based on the set tension; and obtaining the updated speed adjustment coefficient based on the speed update constraints and the speed update objective function.

[0044] According to an embodiment of the present invention, the speed update constraint is determined based on a first preset speed, a set tension, a measured tension, a speed adjustment coefficient, and a tension control equation, including: obtaining the speed update constraint according to formulas (3), (4), (5), (6), (7), and (8). (3) (4) (5) (6) (7) (8) in, The updated predicted tension between the i-th roller and the (i+1)-th roller. The measured tension between the i-th roller and the (i+1)-th roller. Set the tension between the i-th roller and the (i+1)-th roller. To preset the error threshold, This represents the speed adjustment amount for the (i+1)th roller. The speed adjustment amount for the i-th roller is... Let be the updated speed of the (k+1)th roller. Let be the updated speed of the k-th roller. Let k be the current speed of the k-th roller. Let be the current speed of the (k+1)th roller. This represents the speed adjustment amount for the (k+1)th roller. This represents the speed adjustment amount for the k-th roller. The speed adjustment amount for the first roller of the tension heat setter. Let be the current speed of the i-th roller. Let be the current speed of the (i+1)th roller. Let be the updated speed of the (i+1)th roller. Let be the updated speed adjustment coefficient for the i-th roller. Let be the updated speed adjustment coefficient for the k-th roller. Let be the updated speed of the i-th roller. This is the lower limit of the speed of the i-th roller. This represents the upper limit of the speed of the i-th roller. This is the lower limit of the speed of the (i+1)th roller. This represents the upper limit of the speed of the (i+1)th roller. This is the lower limit of the speed of the k-th roller. This represents the upper limit of the speed of the k-th roller. This is the lower limit of the speed of the (k+1)th roller. This represents the upper limit of the speed of the (k+1)th roller. for The solution value, for The solution value, for The solution value.

[0045] According to an embodiment of the present invention, in formula (3), similar to formula (2), This represents the change in tension between the i-th roller and the (i+1)-th roller after adjusting the speed, based on the tension control equation between the i-th roller and the (i+1)-th roller. Therefore, The change in tension between the i-th roller and the (i+1)-th roller, summed with the measured tension between the i-th roller and the (i+1)-th roller before adjustment, can be considered as the tension between the i-th roller and the (i+1)-th roller after speed adjustment, i.e., the updated predicted tension. Since the tension control equation contains errors, the change in tension between the rollers after adjustment can be determined based on the measured tension between the i-th and (i+1)-th rollers before adjustment, and then the updated predicted tension can be determined. This reduces the error in the updated predicted tension caused by the error in the tension control equation, allowing for a more accurate determination of the updated predicted tension. This facilitates the assessment of the tension adjustment effect between the rollers and improves the efficiency of the adjustment.

[0046] According to an embodiment of the present invention, formula (4) is a conditional function, when At this time, the relative error between the measured tension between the i-th roller and the (i+1)-th roller and the corresponding set tension is greater than or equal to a preset error threshold. That is, the tension error between the i-th roller and the (i+1)-th roller is relatively large. The goal of this speed adjustment is to adjust the tension between the i-th roller and the (i+1)-th roller. Therefore, the relative error between the updated predicted tension between the i-th roller and the (i+1)-th roller and the corresponding set tension should be less than the preset error threshold. In other words, the constraint condition is... This is done to adjust the tension between the i-th roller and the (i+1)-th roller.

[0047] According to an embodiment of the present invention, in formula (4), This represents the absolute value of the difference between the set tension between the i-th roller and the (i+1)-th roller and the updated predicted tension. It can be considered as the error between the updated tension between the i-th roller and the (i+1)-th roller and the set tension. Similarly, This can represent the error between the tension of the i-th roller and the (i+1)-th roller before the update and the set tension. When When the measured tension between the i-th roller and the (i+1)-th roller has a relative error of less than the preset error threshold with respect to the corresponding set tension, that is, the tension error between the i-th roller and the (i+1)-th roller is small, and the production stability of the polyester staple fiber between the corresponding rollers meets the requirements. The goal of this speed adjustment is not to adjust the tension between the i-th roller and the (i+1)-th roller, but to adjust the tension between the other rollers. Since the speed of each roller is determined based on a first preset speed and a speed adjustment coefficient, adjusting the tension between one roller will update the tension between all rollers. Therefore, the error between the predicted tension and the set tension between the i-th roller and the (i+1)-th roller after adjustment should be less than the error between the measured tension and the set tension between the same rollers before adjustment. In other words, during the adjustment of the tension between other rollers, the error between the tension and the set tension between the i-th roller and the (i+1)-th roller should remain unchanged or decrease. This is to avoid increasing the error between the tension and the set tension between the i-th roller and the (i+1)-th roller due to adjusting the tension between other rollers, thus affecting production stability. Therefore, the constraint condition is... .

[0048] According to an embodiment of the present invention, in formula (5), This indicates that the change in the first preset speed is 0, meaning the first preset speed remains constant. By updating the speed adjustment coefficient, the speed of each roller is adjusted, thereby adjusting the tension between the rollers. Therefore, the constraint condition is... .

[0049] According to an embodiment of the present invention, in formula (6), since the speed of each roller is determined based on a first preset speed and a speed adjustment coefficient, and the first preset speed is the reference speed when determining the speed of each roller, the updated speed of each roller is solved based on the first preset speed, the updated speed adjustment coefficient of the i-th roller, and in a manner similar to that described above for solving the speed of multiple rollers. That is, the constraint condition is... as well as .

[0050] According to an embodiment of the present invention, since the sum of the current speed of the i-th roller and the speed adjustment amount of the i-th roller should be equal to the updated speed of the i-th roller, the constraint condition can be determined. Similarly, other constraints in formula (7) can be determined, i.e. .

[0051] According to an embodiment of the present invention, since the updated speed of the i-th roller should be greater than or equal to the lower speed limit of the i-th roller (e.g., 150 m / min) and less than or equal to the upper speed limit of the i-th roller (e.g., 200 m / min), the i-th roller operates normally within the speed limit, reducing the probability of polyester staple fiber wear due to excessive roller speed or polyester staple fiber accumulation between rollers due to excessive roller speed. Therefore, the constraint conditions can be determined. Similarly, other constraints in formula (8) can be determined, i.e. .

[0052] According to an embodiment of the present invention, determining the velocity update objective function based on a set tension includes: determining the velocity update objective function according to formula (9). (9) Where N is the total number of rollers in multiple processes, This is the function to be minimized.

[0053] According to an embodiment of the present invention, in formula (9), This represents the speed adjustment amount of the i-th roller. Therefore, This represents the sum of the speed adjustments of each roller in multiple processes. Since large speed adjustments can cause rapid changes in tension between the rollers, posing a significant risk of polyester staple fiber breakage, a function that minimizes the sum of the speed adjustments of each roller in multiple processes can be used. As the speed update objective function, the tension between each roller is adjusted with the minimum speed adjustment, thereby reducing the risk of polyester staple fiber breakage during the adjustment process and maintaining the stability of polyester staple fiber production.

[0054] In this way, based on the measured tension and the set tension between each roller, it can be determined whether the rotational speed of each roller needs to be adjusted. If adjustment is required, the speed update constraints and update objective function are determined. Considering the errors inherent in the tension control equation itself, the fact that adjusting the tension between one roller will update the tension between all rollers, and the risk of polyester staple fiber breakage due to large speed adjustments, multiple speed update constraints and update objective functions are set, improving the accuracy, objectivity, and comprehensiveness of determining the speed update constraints and update objective functions.

[0055] According to an embodiment of the present invention, the updated speed adjustment coefficient is obtained based on the speed update constraints and the speed update objective function. Based on the speed update constraints and the speed update objective function, a constrained optimization problem is constructed, and an optimal solution for the speed adjustment of the i-th roller that satisfies the speed update constraints is found using an optimization algorithm (e.g., genetic algorithm, interior point method, etc.). (That is, the solution that maximizes the achievement of the objective function under the constraints.) , (Optimal solution for constant speed change), and further, using the above optimal solution, the solution value of the speed adjustment coefficient corresponding to each roller can be calculated, which is the updated speed adjustment coefficient.

[0056] According to an embodiment of the present invention, in step S8, the updated rotational speed of the rollers in each process is determined based on the updated speed. Based on the updated speed adjustment coefficient, the speed adjustment coefficients of the rollers in the preceding and subsequent processes of the tension heat setting machine can be reset. Similar to determining the speeds of the rollers in each preceding and subsequent process, the updated speeds of the rollers in each process can be determined based on the updated speed adjustment coefficient and the first preset speed; this is the updated speed. Similarly to determining the rotational speeds of the rollers in the processing, preceding, and subsequent processes of the tension heat setting machine, the updated rotational speeds of the rollers in each process can be obtained by conversion using the updated roller speeds; this is the updated rotational speed. Furthermore, the rotational speeds of the rollers in each process can be updated based on the updated rotational speed to control the tension of the polyester staple fiber between the rollers. After updating the rotational speeds of the rollers in each process, it can be determined whether the rotational speeds of the rollers need adjustment based on the same processing method. If adjustment is needed, the next round of updates is performed until the tension between the adjusted rollers approaches or reaches the set tension, thus completing the adjustment.

[0057] In this way, based on the speed update constraints and the speed update objective function, the updated speed adjustment coefficient can be obtained, thereby determining the updated speed, resulting in the updated rotational speed. This allows for the updating of the roller speeds in each process step, controlling the tension of the polyester staple fiber between the rollers. This improves the accuracy of the updated rotational speed determination and enhances the efficiency and stability of tension control during polyester staple fiber production.

[0058] According to an embodiment of the present invention, the polyester staple fiber tension detection and control method can set a first preset speed and speed adjustment coefficients for the rollers of the preceding and subsequent processing steps during the polyester staple fiber production process, thereby determining the rotational speed of each roller. Based on a tension sensor, the measured tension of the polyester staple fiber between each roller can be detected to determine whether the rotational speed needs adjustment, obtain the tension control equation, and then obtain the updated speed adjustment coefficient to determine the updated rotational speed of the roller. The roller speed can be adjusted according to the tension of the polyester staple fiber in different processes, thereby controlling the tension of the polyester staple fiber, improving the accuracy of the rotational speed, enhancing the accuracy, efficiency, and stability of tension control during the polyester staple fiber production process, and improving the quality of the polyester staple fiber. Furthermore, the speed ratio between adjacent rollers can be determined through the speed adjustment coefficient, thereby determining the elongation ratio of the polyester staple fiber between the two rollers and stabilizing the elongation ratio, facilitating the control of the tension and performance of the polyester staple fiber, and contributing to the improvement of the quality of the polyester staple fiber. The system can also set a first preset speed, as well as speed adjustment coefficients for the rollers in the pre-processing and post-processing stages of the tension heat setting machine, thereby determining the rotational speed of each roller and providing basic data for determining whether the rotational speed of each roller needs adjustment. When determining the tension control equation, the system can determine the fitting equation for the tension control equation between each roller based on the speed and measured tension of each roller during multiple tests, thus determining the tension control equation between each roller. It considers the degree of elongation of the polyester staple fiber bundles in the processes preceding each roller, the length of the polyester staple fiber bundles between rollers, and the deformation of the polyester staple fiber bundles between rollers, and the relationship with the tension between rollers, improving the accuracy, objectivity, and comprehensiveness of the tension control equation determination. When determining the speed update constraints and update objective function, the system can determine whether the rotational speed of each roller needs adjustment based on the measured tension and the set tension between each roller, and if adjustment is required, determine the speed update constraints and update objective function. Considering the inherent errors in the tension control equation, the fact that adjusting the tension between one roller updates the tension between all rollers, and the risk of polyester staple fiber breakage due to large speed adjustments, multiple speed update constraints and objective functions are set to improve the accuracy, objectivity, and comprehensiveness of determining these constraints and objective functions. Furthermore, based on the speed update constraints and objective functions, the updated speed adjustment coefficient can be obtained, thereby determining the updated speed, resulting in the updated rotational speed. This updates the roller speeds for each process, controlling the tension of the polyester staple fiber between rollers. This improves the accuracy of the updated rotational speed determination and enhances the efficiency and stability of tension control during polyester staple fiber production.

[0059] Figure 4 A block diagram of a polyester staple fiber tension detection and control system according to an embodiment of the present invention is shown, the system comprising: The setting module sets the first preset speed of the first roller of the tension heat setter during the production process of polyester staple fiber, and sets the speed adjustment coefficients of the rollers of the pre-process and subsequent processes of the tension heat setter. The speed determination module determines the speed of the rollers in each pre-process of the tension heat setting machine and the speed of the rollers in the subsequent process based on the first preset speed and the speed adjustment coefficient. The rotation speed determination module determines the rotation speed of the processing steps of the tension heat setting machine, the rotation speed of the rollers in the pre-process and the subsequent process based on the first preset speed, the speed of the rollers, and the design parameters of the tension heat setting machine, the pre-process and the subsequent process. The actual tension measurement module uses tension sensors installed between each roller to detect the actual tension of the polyester staple fiber between each roller. The judgment module determines whether the rotational speed of each roller needs to be adjusted based on the measured tension and the set tension between each roller. The tension control equation module obtains the tension control equations between each roller if adjustment is required. The speed adjustment coefficient update module obtains the updated speed adjustment coefficient based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation. Update the speed module and determine the update speed of the rollers in each process based on the updated speed.

[0060] This invention can be a method, apparatus, system, and / or computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for performing various aspects of the invention.

[0061] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting and controlling the tension of polyester staple fiber, characterized in that, include: In the production process of polyester staple fiber, the first preset speed of the first roller of the tension heat setter is set, and the speed adjustment coefficients of the rollers of the pre-process and subsequent processes of the tension heat setter are set. Based on the first preset speed and the speed adjustment coefficient, determine the speed of the rollers in each pre-process of the tension heat setting machine and the speed of the rollers in the subsequent process. Based on the first preset speed, the speed of the rollers, and the design parameters of the tension heat setter, the preceding process, and the following process, the processing steps of the tension heat setter, and the rotational speeds of the rollers in the preceding and following processes are determined. The actual tension of the polyester staple fiber between the rollers is detected by tension sensors installed between the rollers. Based on the measured tension and the set tension between each roller, determine whether the rotational speed of each roller needs to be adjusted; If adjustment is required, obtain the tension control equations between each roller; Based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation, the updated speed adjustment coefficient is obtained; Based on the updated speed, determine the update speed of the rollers for each process.

2. The polyester staple fiber tension detection and control method according to claim 1, characterized in that, Tension sensors are installed between each process step to detect the measured tension of polyester staple fibers in each process step, including: A bundle of polyester staple fibers is placed on one side of the roller of the tension sensor, and a thrust is applied to the roller. The plane of the polyester staple fiber bundle is parallel to the radial section of the roller, and the direction of the thrust is parallel to the radial section of the roller. Determine the start and end positions of the contact section between the polyester staple fiber harness and the roller of the tension sensor; Determine the first angle between the direction of the line connecting any point on the portion of the polyester staple fiber bundle before the roller of the contact tension sensor and the starting position and the horizontal direction, and determine the second angle between the direction of the line connecting any point on the portion of the polyester staple fiber bundle after the roller of the contact tension sensor and the ending position and the horizontal direction. The force exerted by the roller on the pressure probe in the horizontal direction is obtained; The measured tension is determined based on the applied force, the first included angle, and the second included angle.

3. The polyester staple fiber tension detection and control method according to claim 2, characterized in that, The measured tension is determined based on the applied force, the first included angle, and the second included angle, including: According to the formula Determine the measured tension T, where, For the force described, The second included angle, This is the first included angle.

4. The polyester staple fiber tension detection and control method according to claim 1, characterized in that, The method further includes: According to the formula The equation to be fitted is obtained for the tension control equation between the i-th roller and the (i+1)-th roller, where, Let i be the speed of the (i+1)th roller. Let be the speed of the i-th roller. Let be the length of the polyester staple fiber bundle between the i-th roller and the (i+1)-th roller. Let k be the speed of the kth roller. The speed of the (k+1)th roller, , and Let be the coefficients to be fitted for the i-th roller. Let be the residual corresponding to the i-th roller, and if be a conditional function, k ≤ i-1, where k and i are both positive integers; Based on the speed and measured tension of each roller during multiple tests, the fitting coefficients of the tension control equation between the i-th roller and the (i+1)-th roller are solved to obtain the solution values ​​of the fitting coefficients. Based on the solved values ​​of the coefficients to be fitted and the equation to be fitted for the tension control equation between the i-th roller and the (i+1)-th roller, the tension control equation between the i-th roller and the (i+1)-th roller is obtained.

5. The polyester staple fiber tension detection and control method according to claim 1, characterized in that, Based on the measured tension and the set tension between each roller, determine whether the rotational speed of each roller needs to be adjusted, including: Determine the relative error between the measured tension and the set tension; If the relative error is greater than or equal to the preset error threshold, then the rotational speed of each roller needs to be adjusted.

6. The polyester staple fiber tension detection and control method according to claim 4, characterized in that, Based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation, the updated speed adjustment coefficient is obtained, including: Based on the first preset speed, set tension, measured tension, speed adjustment coefficient, and tension control equation, determine the speed update constraint conditions; Based on the set tension, determine the velocity update objective function; Based on the speed update constraints and the speed update objective function, the updated speed adjustment coefficient is obtained.

7. The polyester staple fiber tension detection and control method according to claim 6, characterized in that, Based on the first preset speed, set tension, measured tension, speed adjustment coefficient, and tension control equation, determine the speed update constraints, including: According to the formula Obtain the velocity update constraints, where, The updated predicted tension between the i-th roller and the (i+1)-th roller. The measured tension between the i-th roller and the (i+1)-th roller. Set the tension between the i-th roller and the (i+1)-th roller. To preset the error threshold, This represents the speed adjustment amount for the (i+1)th roller. The speed adjustment amount for the i-th roller is... Let be the updated speed of the (k+1)th roller. Let be the updated speed of the k-th roller. Let k be the current speed of the k-th roller. Let be the current speed of the (k+1)th roller. This represents the speed adjustment amount for the (k+1)th roller. This represents the speed adjustment amount for the k-th roller. The speed adjustment amount for the first roller of the tension heat setter. Let be the current speed of the i-th roller. Let be the current speed of the (i+1)th roller. Let be the updated speed of the (i+1)th roller. Let be the updated speed adjustment coefficient for the i-th roller. Let be the updated speed adjustment coefficient for the k-th roller. Let be the updated speed of the i-th roller. This is the lower limit of the speed of the i-th roller. This represents the upper limit of the speed of the i-th roller. This is the lower limit of the speed of the (i+1)th roller. This represents the upper limit of the speed of the (i+1)th roller. This is the lower limit of the speed of the k-th roller. This represents the upper limit of the speed of the k-th roller. This is the lower limit of the speed of the (k+1)th roller. This represents the upper limit of the speed of the (k+1)th roller. for The solution value, for The solution value, for The solution value.

8. The polyester staple fiber tension detection and control method according to claim 7, characterized in that, Based on the set tension, determine the velocity update objective function, including: According to the formula Determine the speed update objective function, where N is the total number of rollers in multiple processes. This is the function to be minimized.

9. A polyester staple fiber tension detection and control system, characterized in that, include: The setting module sets the first preset speed of the first roller of the tension heat setter during the production process of polyester staple fiber, and sets the speed adjustment coefficients of the rollers of the pre-process and subsequent processes of the tension heat setter. The speed determination module determines the speed of the rollers in each pre-process of the tension heat setting machine and the speed of the rollers in the subsequent process based on the first preset speed and the speed adjustment coefficient. The rotation speed determination module determines the rotation speed of the processing steps of the tension heat setting machine, the rotation speed of the rollers in the pre-process and the subsequent process based on the first preset speed, the speed of the rollers, and the design parameters of the tension heat setting machine, the pre-process and the subsequent process. The actual tension measurement module uses tension sensors installed between each roller to detect the actual tension of the polyester staple fiber between each roller. The judgment module determines whether the rotational speed of each roller needs to be adjusted based on the measured tension and the set tension between each roller. The tension control equation module obtains the tension control equations between each roller if adjustment is required. The speed adjustment coefficient update module obtains the updated speed adjustment coefficient based on the first preset speed, measured tension, set tension, speed adjustment coefficient, and tension control equation. Update the speed module and determine the update speed of the rollers in each process based on the updated speed.

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