Linear servo motor tension structure and control method thereof

Abstract

The application provides a linear servo motor tension structure and a control method thereof, and is applied to the technical field of winding machines. Through the use of high-precision magnetic suspension sliding rails and magnetic grating rulers, real-time and accurate detection of the displacement of the sliding block guide wheel is realized. Combined with the motor torque information of the linear servo motor, the tension control program running through the PLC controller can dynamically calculate and adjust the speed of the linear servo motor and the winding servo motor. This scheme effectively solves the problems of low tension accuracy, insufficient speed control, uneven or curved winding material, etc. caused by the inability of the rotary motor tension to meet the requirements and the lack of preset parameters or manual experience adjustment. It can ensure high-precision constant tension winding of the packaging belt under various working conditions, significantly improve production efficiency and product quality, and eliminate the dependence on manual experience, realizing intelligent and automatic tension control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of winding machines, in particular to a linear servo motor tension structure and a control method thereof. BACKGROUND

[0002] In modern industrial production, especially in scenarios that require precise winding of the strip, such as the production and packaging of packing tape, how to ensure that the tension of the strip is always stable during high-speed operation is the key to ensuring product quality and production efficiency. In order to achieve this goal, a precise linear servo motor tension winding mechanism is usually used. The core components of this mechanism include a linear servo motor, a guide rail module, and a slider guide wheel, which work together to ensure that the strip is wound smoothly and neatly.

[0003] The stable output of the strip tension mainly depends on the torque control mode of the linear servo motor. When the system sets a target tension value, the torque sensor inside the linear servo motor will monitor the actual output torque in real time and compare it with the target value. Through a proportional-integral-derivative (PID) regulator, the system can dynamically adjust the output of the motor to maintain the stability of the torque. However, in actual production, especially in scenarios such as packing tape winding that require high speed and material adaptability, the traditional control method, although it achieves rapid changeover through torque parameter presetting, still faces challenges. When the production line needs to frequently switch between different materials of packing tape and requires high tension stability at extreme high speed, relying solely on preset parameters or manual experience for fine-tuning often fails to achieve optimal results. This not only limits the further improvement of production efficiency, but also may lead to inaccurate tension control when facing new materials or complex working conditions, resulting in problems such as strip wrinkles or breakage. Therefore, how to break away from the dependence on manual experience and achieve fully intelligent and automatic adjustment of tension control parameters to adapt to various materials and extreme high-speed winding requirements has become a technical problem that needs to be solved.

[0004] In view of the above problems, the prior art needs to be improved. SUMMARY

[0005] In view of the above problems of the prior art, the present application provides a linear servo motor tension structure and a control method thereof, aiming to solve the problem that the traditional control method is difficult to maintain high tension stability under frequent switching between different materials and extreme high speed during the winding of packing tape, and the strong dependence on manual experience.

[0006] In a first aspect, a linear servo motor tension structure is provided, which is arranged on a winding machine and used to adjust the tension of packing tape during winding to enable constant tension winding of the packing tape, and at least comprises:

[0007] The linear servo motor at least comprises a stator, a mover and a linear motion module; the stator comprises a high-precision magnetic suspension slide rail, and a high-precision magnetic grating ruler is arranged on the high-precision magnetic suspension slide rail; the mover comprises a magnetic slider, the magnetic slider is movably installed on the high-precision magnetic suspension slide rail and reciprocally runs along the high-precision magnetic suspension slide rail; and the linear motion module at least comprises a driver, the driver drives the magnetic slider to run on the high-precision magnetic suspension slide rail.

[0008] A slider guide wheel is arranged on the magnetic slider, and the packing belt runs through the slider guide wheel along with the magnetic slider, so that the constant tension control is maintained.

[0009] A tension control electric control module at least comprises a PLC controller, the PLC controller runs a tension control program, the tension control program calculates the torque of the linear servo motor and the rotating speed of the winding servo motor according to the slider displacement information of the slider guide wheel detected by the high-precision magnetic grating ruler and the motor torque information of the linear servo motor, so as to control the tension balance of unwinding and winding.

[0010] By the technical scheme, the linear servo motor tension structure integrated with the high-precision magnetic suspension slide rail, the magnetic grating ruler and the PLC controller is provided, the slider displacement and the motor torque can be detected in real time and accurately, the running parameters of the winding machine are dynamically adjusted according to the slider displacement and the motor torque, the constant tension winding of the packing belt is realized, the problem of unstable tension control of the traditional method in the high-speed and multi-material switching scene is effectively solved, and the production efficiency and the product quality are significantly improved.

[0011] In a second aspect, a control method of a linear servo motor tension structure is applied to the linear servo motor tension structure, and the control method comprises the following steps:

[0012] S1: obtaining running data of the linear servo motor tension structure, the running data at least comprising motor torque information and slider displacement information;

[0013] S2: calculating a tension fluctuation amplitude and a tension response speed based on the motor torque information, calculating displacement stability of the slider guide wheel based on the slider displacement information, and identifying a small vibration frequency of the belt based on the motor torque information or the slider displacement information;

[0014] S3: evaluating tension control system performance and belt dynamic characteristics based on the tension fluctuation amplitude, the tension response speed, the displacement stability and the small vibration frequency of the belt, and obtaining an evaluation result;

[0015] S4: calculating torque control parameters of the linear servo motor and rotating speed correction parameters of the winding servo motor by using a PID algorithm according to the evaluation result;

[0016] S5: controlling the linear servo motor to operate according to the torque control parameter and controlling the winding servo motor to operate according to the rotating speed correction parameter.

[0017] By the technical solution, intelligent control of the linear servo motor tension structure can be realized, real-time data acquisition and multi-dimensional performance evaluation are performed, control parameters are dynamically adjusted, and the precision and stability of tension control are effectively improved, thereby eliminating the dependence on artificial experience.

[0018] Further, the step S2 comprises:

[0019] S21: acquiring the strip tension data according to the motor torque information, and calculating the standard deviation of the strip tension data as an index of the tension fluctuation amplitude;

[0020] S22: recording the time required from the tension control instruction being issued to the strip tension data reflected by the motor torque information reaching a preset percentage of the new target value as an index of the tension response speed;

[0021] S23: acquiring the slider guide displacement according to the slider displacement information, and calculating the root mean square error of the slider guide displacement as an index of the displacement stability;

[0022] S24: performing frequency spectrum analysis on the motor torque information or the slider displacement information, identifying the energy concentrated frequency components, and obtaining the strip slight vibration frequency.

[0023] By the technical solution, a specific method for quantitatively evaluating the tension fluctuation, the response speed, the displacement stability and the strip vibration frequency can be provided, and accurate data support for subsequent system performance evaluation and parameter adjustment can be provided.

[0024] Further, the step S3 comprises:

[0025] S31: defining multiple operating states, the operating states comprising a starting state, a stable state, a transition state and an abnormal state;

[0026] S32: setting evaluation thresholds for the operating states;

[0027] S33: judging the operating state currently taken by the winding machine according to the evaluation thresholds based on the tension fluctuation amplitude, the tension response speed, the displacement stability and the strip slight vibration frequency;

[0028] S34: evaluating the system performance level in the operating state currently taken by the winding machine;

[0029] S35: taking the operating state and the system performance level as the evaluation result.

[0030] Through the technical scheme, intelligent identification of the running state of the winding machine and quantitative evaluation of the system performance can be realized, a decision basis is provided for subsequent adaptive parameter adjustment, and the intelligent level of the control system is improved.

[0031] Further, the step S33 comprises:

[0032] S331: if the tension fluctuation amplitude exceeds the corresponding preset abnormal threshold, it is judged that the winding machine is currently in an abnormal state, otherwise it is not in an abnormal state;

[0033] S332: if it is not in an abnormal state, the winding speed of the winding machine is obtained, if the winding speed is lower than the preset start completion speed and the tension response speed is higher than the preset response threshold, it is judged that it is in a start state, otherwise it is not in a start state;

[0034] S333: if it is not in a start state, it is judged whether any of the tension fluctuation amplitude, displacement stability and strip slight vibration frequency exceeds the corresponding preset stability threshold, if it exceeds the corresponding preset stability threshold but does not reach the corresponding preset abnormal threshold, it is judged that the winding machine is currently in a transition state, if it does not exceed the corresponding preset stability threshold, it is judged that the winding machine is currently in a stable state.

[0035] Further, the step S34 comprises:

[0036] S341: when the system is in a non-abnormal state, a set of ideal performance reference thresholds is preset for the running state in which the winding machine is currently located;

[0037] S342: the deviation degree of the tension fluctuation amplitude, the tension response speed, the displacement stability and the strip slight vibration frequency from the ideal performance reference threshold is calculated;

[0038] S343: according to the deviation degree, the system performance level is determined.

[0039] Further, the step S4 comprises:

[0040] S41: according to the running state and the system performance level, the proportional gain, the integral gain and the differential gain of the PID controller, and the torque feedforward amount and the speed feedforward amount of the linear servo motor are determined from the preset parameter mapping table;

[0041] S42: the proportional gain, the integral gain, the differential gain and the torque feedforward amount are collectively used as the torque control parameters of the linear servo motor, and the speed feedforward amount is used as the speed correction parameter of the winding servo motor.

[0042] Further, the step S41 comprises:

[0043] S411: continuously acquiring the running state and the system performance level during the operation of the winding machine;

[0044] S412: judging whether the system performance level is lower than a preset optimization target;

[0045] S413: if the system performance level is lower than the optimization target, adjusting the parameter set corresponding to the current running state in the parameter mapping table according to the deviation degree of the system performance level from the optimization target;

[0046] S414: updating the adjusted parameter set to the parameter mapping table, and determining the proportional gain, integral gain and differential gain of the PID controller, and the torque feedforward and speed feedforward of the linear servo motor from the updated parameter mapping table.

[0047] Further, step S413 comprises:

[0048] S4131: recording the running state, system performance level, deviation degree and historical parameter adjustment result, and constructing a historical adjustment database;

[0049] S4132: retrieving similar historical data from the historical adjustment database according to the current running state and system performance level;

[0050] S4133: adjusting the parameter set corresponding to the current running state in the parameter mapping table in combination with the current deviation degree and the retrieved similar historical data.

[0051] Further, step S414 comprises:

[0052] S4141: taking the running state and system performance level as indexes to search in the updated parameter mapping table to obtain parameter values;

[0053] S4142: performing interpolation calculation on the parameter values to obtain the proportional gain, integral gain and differential gain of the PID controller, and the torque feedforward and speed feedforward of the linear servo motor.

[0054] Beneficial effects: The linear servo motor tension structure and control method provided by the application effectively solves the problems of unstable tension control and strong dependence on manual experience in the existing technology during the winding process of the packaging belt. Specifically, the structure uses high-precision magnetic suspension rails and magnetic grating rulers to realize real-time and accurate detection of the displacement of the slider guide wheel, combines the motor torque information of the linear servo motor, and dynamically calculates and adjusts the speed of the linear servo motor and the winding servo motor through the tension control program running by the PLC controller. This closed-loop control mechanism enables the packaging belt to maintain constant tension during the winding process, even under complex working conditions such as high-speed operation or frequent switching of different material packaging belts, and ensures high stability of the tension. Compared with the traditional control method relying on preset parameters or manual experience, the technical solution of the application significantly improves the precision, response speed and self-adaptive ability of the tension control, thereby effectively avoiding problems such as belt wrinkles and breakage, improving product quality and production efficiency, and realizing the intelligentization and automation of tension control. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 An installation schematic diagram of the linear servo motor tension structure provided by the application.

[0056] Figure 2 A perspective view of the linear servo motor tension structure provided by the application.

[0057] Figure 3 A flowchart of the control method of the linear servo motor tension structure provided by the application.

[0058] Label explanation: 1, winding machine; 2, linear servo motor tension structure; 21, linear servo motor; 22, stator; 23, rotor; 11, vertical mounting plate; 221, high-precision magnetic suspension rail; 24, slider guide wheel; 232, magnetic slider; 25, cable drag chain. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. The components of the embodiments of the application described and indicated in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0060] It should be noted that similar reference numerals and letters refer to like items in the accompanying drawings, and once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings. Also, in the description of the present application, the terms "first", "second", and the like are used only to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

[0061] Please refer to Figure 1 , Figure 2 A linear servo motor tension structure 2 is arranged on a winding machine 1, and is used for adjusting the tension of a packing belt during winding, so that the packing belt is wound with constant tension, and at least comprises:

[0062] A linear servo motor 21 at least comprises a stator 22, a mover 23, and a linear motion module; the stator 22 comprises a high-precision magnetic suspension slide rail 221, and a high-precision magnetic grating scale is arranged on the high-precision magnetic suspension slide rail 221; the mover 23 comprises a magnetic slider 232, the magnetic slider 232 is movably installed on the high-precision magnetic suspension slide rail 221, and reciprocally moves along the high-precision magnetic suspension slide rail 221; the linear motion module at least comprises a driver, and the driver drives the magnetic slider 232 to move on the high-precision magnetic suspension slide rail 221;

[0063] A slider guide wheel 24 is arranged on the magnetic slider 232, and the packing belt moves along with the magnetic slider 232 through the slider guide wheel 24, so that the constant tension control is maintained;

[0064] A tension control electric control module at least comprises a PLC controller, the PLC controller runs a tension control program, the tension control program calculates the torque of the linear servo motor 21 and the rotating speed of the winding servo motor according to the slider displacement information of the slider guide wheel 24 detected by the high-precision magnetic grating scale and the motor torque information of the linear servo motor 21, so as to control the tension balance of unwinding and winding.

[0065] The linear servo motor tension structure 2 provided in the present application aims to provide a solution capable of realizing constant tension winding of a packing belt. The linear servo motor 21 is an actuator capable of converting electric energy into linear motion, and has the characteristics of high precision, high response speed and high torque output, and is used in the present application to provide the power required for tension adjustment.

[0066] The stator 22 is a fixed part of the linear servo motor 21.

[0067] The mover 23 is a movable part of the linear servo motor 21, and moves on the high-precision magnetic suspension slide rail 221.

[0068] The high-precision magnetic suspension slide rail 221 is a guide rail system that realizes non-contact suspension and movement by using magnetic force, and has the advantages of small friction, high precision, long service life, etc.

[0069] High-precision magnetic scale is a kind of sensor that uses magnetic field change to measure displacement, which can provide accurate displacement information.

[0070] Linear motion module is an auxiliary mechanism to realize the linear motion of magnetic slider 232, which at least includes a driver. The driver converts the input electrical energy into electric current, drives the magnetic slider 232 to generate a magnetic field, and thus makes the magnetic slider 232 interact with the magnetic field of the high-precision magnetic levitation rail 221 to directly generate linear thrust. The linear motion module also includes a cable and a cable drag chain 25 to protect the cable. The cable at least includes a power line connected to the magnetic slider 232 and a reading head line of the high-precision magnetic scale.

[0071] Slider guide wheel 24 is a component that directly contacts the packaging belt, and its displacement change directly reflects the tension state of the packaging belt.

[0072] Tension control electronic control module is the core control unit of the entire system. The PLC controller is an industrial automation control device responsible for running the tension control program. The program processes various sensor data to achieve coordinated control of the linear servo motor 21 and the winding servo motor, ultimately achieving constant tension winding.

[0073] Specifically, the linear servo motor 21 is the power core of the entire tension adjustment system. The linear servo motor 21 at least includes a stator 22, a mover 23, and a linear motion module. The stator 22 part can be implemented in various ways. For example, the stator 22 can be composed of one or more arrays of permanent magnets that are precisely fixed on a base to form a high-precision magnetic levitation rail 221. The high-precision magnetic levitation rail 221 is fixed on the vertical mounting plate 11 of the winding machine 1, and its main function is to provide an accurate linear motion track for the slider guide wheel 24. The positioning accuracy of the high-precision magnetic levitation rail 221 is within an error range of ±0.01 mm.

[0074] The high-precision magnetic levitation rail 221 is configured with a high-precision magnetic scale (with an accuracy of ±1 pm to ±5 pm). The high-precision magnetic scale can be implemented by embedding magnetic encoding strips on the side or inside of the rail, and detecting the change of the magnetic field through a reading head to obtain accurate displacement information.

[0075] The mover 23 part at least includes a magnetic slider 232. The magnetic slider 232 can be implemented as a slider with a permanent magnet that generates thrust by interacting with the magnetic field on the stator 22.

[0076] The linear motion module at least includes a driver and a cable drag chain 25. The cable drag chain 25 can be implemented as a flexible chain that internally accommodates cables and bends or stretches with the movement of the magnetic slider 232. The driver drives the magnetic slider 232 to run on the high-precision magnetic levitation rail 221. The driver can be a servo driver that receives instructions from a control system and accurately controls the current input to the magnetic slider 232, thereby achieving accurate control of the position and speed of the magnetic slider 232.

[0077] The slider guide wheel 24 is arranged on the magnetic slider 232, and the packing belt runs through the slider guide wheel 24 with the magnetic slider 232, thereby maintaining constant tension control. The slider guide wheel 24 can be implemented as a low-friction roller with a bearing design that ensures smooth rotation even at high speeds, reducing wear on the packing belt.

[0078] The tension control electronic control module at least includes a PLC controller. The PLC controller can be an industrial-grade programmable logic controller that internally runs a tension control program. The tension control program calculates the rotation speed of the linear servo motor 21 and the winding servo motor based on the slider displacement information of the slider guide wheel 24 detected by the high-precision magnetic scale and the motor torque information of the linear servo motor 21, thereby controlling the tension balance of unwinding and winding. Specifically, the tension control program first calculates a series of performance indicators such as tension fluctuation, response speed, and displacement stability based on real-time acquired motor torque information and slider displacement information. Then, according to the evaluation results of these indicators, the program calculates two sets of key parameters using the PID algorithm: one is the torque control parameter (such as PID gain and torque feedforward) for the linear servo motor 21, and the other is the rotation speed correction parameter (such as rotation speed feedforward) for the winding servo motor. In application, the linear servo motor 21 adjusts the thrust at high frequency and precision according to its torque parameter to directly maintain the constant tension of the packing belt (force control); at the same time, the winding servo motor adjusts its rotation speed according to its rotation speed correction parameter (mainly based on the system balance state reflected by the slider displacement information) to match the overall winding speed of the material (speed control). It is this "force" and "speed" cooperative control that ultimately achieves the tension balance of unwinding and winding.

[0079] The tension control program can be implemented as a control program based on the PID algorithm, which dynamically adjusts the output of the linear servo motor 21 and the winding servo motor by real-time monitoring of the slider displacement and motor torque to maintain the constant tension of the packing belt.

[0080] Compared with the traditional tension control scheme, the application greatly improves the accuracy and response speed of displacement detection by introducing a high-precision magnetic suspension slide rail 221 and a high-precision magnetic scale. The use of the high-precision magnetic suspension slide rail 221 eliminates mechanical friction, making the movement of the magnetic slider 232 smoother and more accurate, thereby enabling more sensitive reflection of the small tension changes of the packaging belt. The high-precision magnetic scale provides centimeter-level or even millimeter-level displacement feedback, providing more accurate real-time data for the tension control program.

[0081] In addition, the tension control program run by the PLC controller in the tension control electric control module can intelligently calculate and adjust according to the slider displacement information detected by the high-precision magnetic scale and the motor torque information of the linear servo motor 21. This dynamic control mechanism based on real-time data feedback enables the system to break away from the dependence on manual experience and realize automatic and intelligent adjustment of tension control parameters. Regardless of the material of the packaging belt or the speed limit of the winding speed, the system can ensure that the packaging belt is always in a constant tension state through accurate calculation and coordinated control of the rotational speed of the linear servo motor 21 and the winding servo motor.

[0082] Please refer to Figure 3 A control method of the linear servo motor tension structure 2 is applied to the linear servo motor tension structure 2 described above, and the control method comprises the steps of:

[0083] S1: obtaining the running data of the linear servo motor tension structure 2, the running data at least including motor torque information and slider displacement information;

[0084] S2: calculating the tension fluctuation amplitude and the tension response speed based on the motor torque information, calculating the displacement stability of the slider guide wheel 24 based on the slider displacement information, and identifying the small vibration frequency of the belt based on the motor torque information or the slider displacement information;

[0085] S3: based on the tension fluctuation amplitude, the tension response speed, the displacement stability, and the small vibration frequency of the belt, evaluating the performance of the tension control system and the dynamic characteristics of the belt to obtain an evaluation result;

[0086] S4: according to the evaluation result, calculating the torque control parameters of the linear servo motor 21 and the rotational speed correction parameters of the winding servo motor by using the PID algorithm;

[0087] S5: controlling the linear servo motor 21 to run according to the torque control parameters, and controlling the winding servo motor to run according to the rotational speed correction parameters.

[0088] Specifically, the above control method aims to ensure that the packaging belt maintains a constant tension during the winding process through real-time monitoring and dynamic adjustment.

[0089] In step S1, the running data of the linear servo motor tension structure 2 is acquired. The running data is a real-time reflection of the system running state, at least including the motor torque information of the linear servo motor 21 and the slider displacement information of the slider guide wheel 24. The motor torque information is directly related to the tension of the packaging belt, and the slider displacement information reflects the dynamic response and stability of the tension adjusting mechanism.

[0090] Further, in step S2, the calculation of key performance indicators is based on the acquired running data. Specifically, the tension fluctuation amplitude and the tension response speed are calculated based on the motor torque information, which respectively quantify the fluctuation degree of the tension around the target value and the response speed of the system to the change of the tension instruction. The displacement stability of the slider guide wheel 24 is calculated based on the slider displacement information, which measures the smoothness of the slider guide wheel 24 in the linear motion process. In addition, by performing frequency spectrum analysis on the motor torque information or the slider displacement information, the possible small vibration frequency of the strip during the winding process can be identified, which is crucial for diagnosing and suppressing resonance phenomenon.

[0091] Therefore, in step S3, based on the tension fluctuation amplitude, the tension response speed, the displacement stability and the small vibration frequency of the strip calculated above, the overall performance of the tension control system and the dynamic characteristics of the packaging belt are comprehensively evaluated, so as to obtain a comprehensive evaluation result. The evaluation result provides a decision basis for subsequent control parameter adjustment.

[0092] In this application, the dynamic characteristics of the strip are an important factor affecting the stability of the tension control system. In step S2 of the method, the motor torque or slider displacement information is analyzed by frequency spectrum analysis, and is quantified as the technical indicator of the small vibration frequency of the strip. Therefore, in step S3, the dynamic characteristics of the strip are evaluated, not as an independent evaluation parameter, but as an input for S3 evaluation together with the tension fluctuation amplitude, the tension response speed, the displacement stability and other indicators.

[0093] In addition, as defined in steps S31 to S35, the evaluation result defined in this application is a combined result, specifically including two parts of "running state" and "system performance level".

[0094] The dynamic characteristic index of the strip micro-vibration frequency is used in the following two aspects in the S3 evaluation process: first, to determine the running state: as described in step S333, the system determines whether the strip micro-vibration frequency index exceeds the preset stable threshold. If the index (or other indexes such as tension fluctuation, displacement stability) exceeds the stable threshold but does not reach the abnormal threshold, the system determines that the current is in a “transition state”. Second, to evaluate the system performance level: as described in step S34, after determining the running state, the system evaluates the system performance level in the state. The evaluation is based on the deviation of all key indexes such as the strip micro-vibration frequency from the ideal performance reference curve.

[0095] As a preferred embodiment, in step S4, according to the evaluation result obtained in step S3, the torque control parameters of the linear servo motor 21 and the speed correction parameters of the winding servo motor are calculated using the PID (Proportional-Integral-Derivative) algorithm. The PID algorithm is a feedback control algorithm widely used in industrial control field, which can adjust the control output according to the proportion, integral and differential items of system error to achieve accurate control. The torque control parameters are used to directly adjust the output torque of the linear servo motor 21, thereby accurately controlling the tension of the packaging belt. Specifically, the torque control parameters mainly include proportional gain (P), integral gain (I), differential gain (D) and torque feedforward. They work together to adjust the output torque of the linear servo motor, and the specific process is as follows:

[0096] The system will continuously compare the target tension value with the actual tension reflected by the motor torque information. When there is an error between the two, the PID regulator will calculate a correction torque according to the set proportional gain, integral gain and differential gain parameters. These parameters determine the strength and speed of the controller's response to the current error (P), cumulative error (I) and error change rate (D).

[0097] In order to improve the response speed and anti-interference ability of the system, the system also uses torque feedforward. This is a predictive parameter that, before a disturbance (such as a change in winding speed or start-up), applies a compensating torque in advance according to the known system model or experience. For example, an initial torque feedforward is applied at start-up to overcome inertia and friction, or the output torque is adjusted in advance according to the change in winding diameter.

[0098] Finally, the PLC controller combines the correction torque calculated by the PID with the torque feedforward to generate a final torque control command. The command is sent to the driver of the linear servo motor, which accurately controls the current and magnetic field of the motor, thereby producing an accurate output torque consistent with the command to maintain a constant tension of the packaging belt.

[0099] The speed correction parameter is used to fine-tune the speed of the winding servo motor, so as to maintain the constant tension winding together with the linear servo motor 21. Specifically, the PLC controller monitors the displacement information of the slider detected by the high-precision magnetic scale in real time. This displacement information directly reflects whether the speed between the unwinding and winding links matches.

[0100] If the speed of the winding servo motor is slower than the material supply speed, the packaging belt will tend to be loose, and the position of the slider guide wheel (mover) will deviate to one side. Conversely, if the speed is faster than the supply speed, the packaging belt will be too tight, and the slider guide wheel will deviate to the other side.

[0101] The tension control program in the PLC processes this slider displacement information. It takes the speed correction parameter (such as the speed feedforward amount) as the reference, and according to the deviation degree and direction of the slider displacement, calculates an accurate speed adjustment instruction. The instruction is sent to the driver of the winding servo motor to fine-tune its speed (increase or decrease).

[0102] In this way, the system can ensure that the speed of the winding motor is perfectly coordinated with the tension system adjusted by the linear servo motor, so that the slider guide wheel always maintains a dynamic balance at the center position, thereby realizing long-term constant tension winding.

[0103] Finally, in step S5, according to the torque control parameter and the speed correction parameter calculated in step S4, the linear servo motor 21 and the winding servo motor are respectively controlled accurately, so that they operate according to the preset tension target, thereby realizing constant tension winding of the packaging belt.

[0104] The scheme of the present application effectively solves the problem that the traditional linear servo motor tension structure 2 is difficult to maintain accurate constant tension under dynamic working conditions by constructing a "displacement detection-signal feedback-speed regulation" closed-loop feedback control system. Specifically, in some preferred embodiments, it is assumed that on a certain winding machine 1, a PET packaging belt with a width of 50 mm needs to be wound with constant tension.

[0105] First, in step S1, the motor torque information is collected in real time by the high-precision torque sensor installed on the linear servo motor 21, and the slider displacement information of the slider guide wheel 24 is obtained in real time by the high-precision magnetic scale installed on the high-precision magnetic levitation guide rail 221. These data are acquired by the control system at a frequency of once per millisecond.

[0106] Then, in step S2, the control system processes the acquired data. For example, the tension fluctuation amplitude is obtained by calculating the standard deviation of the motor torque in the past 1 second; the tension response speed is measured by recording the time required for the actual tension to reach 90% of the new set value from the change of the tension set value; the displacement stability is evaluated by calculating the root mean square error of the displacement amount of the magnetic slider 232 in a period of time; at the same time, the motor torque information is subjected to fast Fourier transform (FFT) to identify the possible micro-vibration frequency of the packaging belt, such as 20Hz periodic vibration.

[0107] Subsequently, in step S3, the control system evaluates the performance level of the current tension control system and the dynamic characteristics of the packaging belt according to the calculated tension fluctuation amplitude, tension response speed, displacement stability and belt micro-vibration frequency, combined with the pre-set performance threshold. For example, if the evaluation shows that:

[0108] The system performance level index is poor (such as: the tension fluctuation amplitude exceeds 0.5N, the tension response speed is slower than 200ms, and the displacement stability root mean square error is greater than 0.1mm); the dynamic characteristics of the belt are evaluated as "there is obvious 20Hz vibration" through spectrum analysis, the evaluation result may indicate that the system is in "transition state" or "stable state".

[0109] Based on this evaluation result, in step S4, the control system dynamically adjusts the proportional gain, integral gain and differential gain of the PID controller, as well as the torque feedforward of the linear servo motor 21 and the speed feedforward of the winding servo motor, according to the current system state and target performance requirements, using the PID algorithm. For example, if the system response speed is slow, the proportional gain and integral gain may be appropriately increased; if there is vibration, the differential gain may be adjusted or a notch filter may be introduced.

[0110] Finally, in step S5, these calculated and adjusted torque control parameters and speed correction parameters are sent in real time to the drivers of the linear servo motor 21 and the winding servo motor, so as to accurately control the operation of the linear servo motor 21, so that the torque output by the linear servo motor 21 can accurately offset the tension fluctuation, and work cooperatively with the winding servo motor, to ensure that the packaging belt always maintains the pre-set constant tension, such as 100N, during the entire winding process. Through this dynamic and adaptive control method, even in the case of changing winding speed or uneven packaging belt material, the tension can be effectively maintained stable.

[0111] Further, step S2 includes:

[0112] S21: According to the motor torque information, the belt tension data is acquired, and the standard deviation of the belt tension data is calculated as an index of the tension fluctuation amplitude;

[0113] S22: Record the time required for the strip tension data reflected by the motor torque information to reach the preset percentage of the new target value from the tension control instruction as an indicator of tension response speed;

[0114] S23: According to the slider displacement information, the displacement of the slider guide wheel 24 is obtained, and the root mean square error of the displacement of the slider guide wheel 24 is calculated as an indicator of displacement stability;

[0115] S24: Perform frequency spectrum analysis on the motor torque information or the slider displacement information, identify the energy concentrated frequency components, and obtain the strip micro-vibration frequency.

[0116] In step S21, the motor torque information can be understood as the real-time torque data generated by the linear servo motor 21 during operation, which can be directly obtained through the motor controller. The strip tension data can be calculated based on the motor torque information, and the specific calculation formula is strip tension = motor torque / slider guide wheel radius. In practical application, the specific radius of the slider guide wheel 24 needs to be matched according to the width of the packaging belt. For example, when the guide wheel radius is 30 mm, if the motor outputs 0.6 N·m torque, it can be converted to 20 N strip tension. The standard deviation of the strip tension data is calculated, which aims to quantify the degree of dispersion of the tension data around its mean value. The larger the standard deviation, the more intense the tension fluctuation, thereby providing an objective and quantitative tension fluctuation amplitude indicator.

[0117] In step S22, the tension control instruction refers to the target tension value set by the system by manual. The preset percentage of the new target value, for example, can be set to 90% or 95%, which aims to provide an actually acceptable stable range before the tension reaches complete stability, in order to more truly reflect the response speed of the system. The time required for the tension data to first enter and remain within the preset percentage range from the issuance of the instruction can directly measure the response ability of the tension control system to changes in the tension set value.

[0118] In step S23, the slider displacement information is usually collected by the built-in high-precision magnetic grating ruler in the linear servo motor 21. The displacement of the slider guide wheel 24 can be directly extracted from the slider displacement information or obtained through filtering. The root mean square error of the displacement of the slider guide wheel 24 is calculated, which aims to evaluate the smoothness of the slider guide wheel 24 during linear motion. The root mean square error can effectively reflect the degree of displacement jitter or deviation, thereby serving as a quantitative indicator of displacement stability.

[0119] In step S24, the motor torque information or the slider displacement information is subjected to a spectral analysis, for example using a Fast Fourier Transform (FFT) or other signal processing techniques. The purpose is to convert the time domain signal into a frequency domain signal, thereby identifying the frequency components where the energy is concentrated. These frequency components where the energy is concentrated usually correspond to the small vibration frequencies that can exist during the winding process, for example caused by mechanical resonance, imbalance or inherent frequencies of the control system. Identifying these frequencies helps to diagnose and locate the source of the vibrations.

[0120] By the above technical solutions, the calculation processes of the tension fluctuation amplitude, the tension response speed, the displacement stability and the small vibration frequency of the strip are standardized and quantified, which significantly improves the accuracy and reliability of the evaluation of these key performance indicators. This enables the system to more accurately grasp the tension state and the dynamic behavior of the strip during the winding process, providing a more solid data foundation for subsequent PID algorithm parameter calculation, thereby helping to achieve more fine and stable constant tension winding control and effectively avoiding control deviation or system instability caused by inaccurate evaluation.

[0121] Further, step S3 includes:

[0122] S31: defining a plurality of operating states, the operating states including a start-up state, a stable state, a transition state and an abnormal state;

[0123] S32: setting evaluation thresholds for the operating states;

[0124] S33: judging the current operating state of the winding machine 1 based on the tension fluctuation amplitude, the tension response speed, the displacement stability and the small vibration frequency of the strip according to the evaluation thresholds;

[0125] S34: evaluating the system performance level in the current operating state of the winding machine 1;

[0126] S35: taking the operating state and the system performance level as the evaluation results.

[0127] Specifically, in step S31, a plurality of operating states of the winding machine 1 are defined, including a start-up state, a stable state, a transition state and an abnormal state. These states are intended to comprehensively cover various working conditions that the winding machine 1 can encounter in actual operation, so as to take different evaluation strategies and control measures for different working conditions. For example, the start-up state usually refers to the stage from the winding machine 1 being stationary to reaching the preset running speed; the stable state refers to the stage of the winding machine 1 running stably at the preset speed for a long time; the transition state can refer to the dynamic adjustment stage when the winding speed or the tension value changes; and the abnormal state refers to the situation where the system has a fault or the performance deviates seriously from the expectation.

[0128] In step S32, an evaluation threshold is set for each of the above-defined operating states. These evaluation thresholds are determined based on historical operation data, theoretical models or actual test results, and are used to quantitatively determine whether the system is in a certain state and whether the system performance meets the requirements in that state. Preferably, statistical analysis based on historical operation data is used to calculate the mean and standard deviation of each performance indicator, and then the mean plus or minus twice or three times the standard deviation is used as the threshold. For the tension fluctuation amplitude, a maximum allowed standard deviation can be set, for example 0.5 N. For the tension response speed, a maximum allowed time can be set, for example 200 ms. For the displacement stability of the slider guide wheel 24, a maximum allowed root mean square error can be set, for example 0.1 mm. For the small vibration frequency of the strip, an energy concentration threshold can be set, for example when the energy proportion in a certain frequency range exceeds 15%, it is considered that there is significant vibration. These thresholds can be stored in the memory of the control system, or managed through a configuration file, so as to be dynamically loaded and updated during system operation.

[0129] In step S33, the tension fluctuation amplitude, tension response speed, displacement stability and small vibration frequency of the strip calculated in step S2 are compared with the pre-set evaluation thresholds to determine the specific operating state of the winding machine 1. This determination process is dynamic and can reflect the working condition changes of the winding machine 1 in real time.

[0130] In step S34, after determining the operating state of the winding machine 1, the system performance level in that operating state is evaluated. This evaluation can be based on the deviation of each indicator in the current state from the ideal performance indicator, or compared with the pre-set performance standard in that state.

[0131] Step S35 outputs the operating state determined in step S33 and the system performance level evaluated in step S34 as the final evaluation result, providing accurate and comprehensive basis for the calculation of torque control parameters and speed correction parameters in the subsequent steps.

[0132] In some preferred embodiments, it is assumed that the winding machine 1 is in the process of starting up first. At this time, the system monitors the tension fluctuation amplitude, tension response speed, displacement stability of the slider guide wheel 24, and the small vibration frequency of the strip. For example, at the beginning of the start-up, the tension response speed can be high, and the tension fluctuation amplitude can also be large, but as long as these indicators are within the evaluation threshold range preset in the starting state, the system judges it as a normal starting process. Once the winding speed reaches the preset value, and the tension indicators tend to be stable, the system will judge it to enter the stable state according to the evaluation threshold. In the stable state, the requirements for tension fluctuation amplitude, displacement stability and other indicators will be more stringent, and any fluctuation exceeding the stable threshold value can be identified as a transition state or an abnormal state. For example, if the small vibration frequency of the strip suddenly rises and exceeds the stable threshold value, but does not reach the abnormal threshold value, the system will judge it as a transition state and evaluate its performance level to adjust the control parameters in time. If the tension fluctuation amplitude suddenly exceeds the abnormal threshold value by a large margin, the system will immediately judge it as an abnormal state and trigger the corresponding alarm or protection mechanism. Through this state-division and threshold-division evaluation mechanism, the system can accurately grasp the running condition of the winding machine 1 in real time, and provide accurate input for subsequent adaptive control.

[0133] Further, step S33 comprises:

[0134] S331: If the tension fluctuation amplitude exceeds the corresponding preset abnormal threshold value, it is judged that the winding machine 1 is currently in an abnormal state, otherwise it is not in an abnormal state;

[0135] S332: If it is not in an abnormal state, the winding speed of the winding machine 1 is obtained, and if the winding speed is lower than the preset start-up completion speed and the tension response speed is higher than the preset response threshold value, it is judged as a starting state, otherwise it is not in a starting state;

[0136] S333: If it is not in a starting state, it is judged whether any one of the tension fluctuation amplitude, displacement stability and small vibration frequency of the strip exceeds the corresponding preset stable threshold value, if it exceeds the corresponding preset stable threshold value but does not reach the corresponding preset abnormal threshold value, it is judged that the winding machine 1 is currently in a transition state; if it does not exceed the corresponding preset stable threshold value, it is judged that the winding machine 1 is currently in a stable state.

[0137] Specifically, the preset abnormal threshold, the preset start-up completion speed, the preset response threshold, and the preset stable threshold can be preset according to actual application scenarios and experience. For example, the preset abnormal threshold can be set to trigger when the tension fluctuation amplitude exceeds a certain percentage of the normal operating range, indicating a potential failure or serious deviation. The preset start-up completion speed can be defined as a certain percentage, such as 80% or 90%, of the winding machine 1 reaching its rated operating speed. The preset response threshold can be set as an upper limit of the tension response speed, and if it exceeds this value, the system response is considered too slow. The preset stable threshold is used to define the system's performance within the normal fluctuation range, for example, when any of the tension fluctuation amplitude, displacement stability, or strip micro-vibration frequency exceeds this threshold but does not reach the respective preset abnormal threshold, indicating that the system may be in a non-ideal but controllable transition state.

[0138] The scheme of the present application solves the ambiguity problem that may exist in the state judgment of the traditional method by introducing a layered and prioritized judgment logic. First, the system prioritizes the judgment of whether the winding machine 1 is in an abnormal state, because the abnormal state usually needs immediate attention and processing, and its judgment is based on the key indicator of tension fluctuation amplitude, which can quickly identify serious deviations in system operation. Secondly, after excluding the abnormal state, the system judges whether it is in a start-up state, which combines winding speed and tension response speed, and can accurately capture the transition phase characteristics of the winding machine 1 from static to normal operation. Finally, in the non- abnormal and non-start-up state, the system further distinguishes between the transition state and the stable state by checking whether the tension fluctuation amplitude, displacement stability, and strip micro-vibration frequency exceed the respective preset stable thresholds, which can finely identify subtle changes in system performance. This progressive judgment mechanism ensures that the running state of the winding machine 1 can be accurately and unambiguously classified at any time.

[0139] By the above technical solution, the running state of the winding machine 1 can be more accurately and reliably identified. This refined state judgment avoids misjudgment or delayed response due to ambiguous state, so that the subsequent control parameter adjustment can be more targeted. Specifically, when the system is in an abnormal state, emergency shutdown or alarm can be triggered; when in the starting state, a specific starting control strategy can be adopted, for example: when the winding machine 1 starts from a stationary state, the control system first identifies that it is currently in the starting state. At this time, the control system activates a set of pre-set starting control strategy. At the moment of motor starting, the linear servo motor 21 driver applies a pre-set initial torque feed to quickly overcome the system inertia and friction, avoiding the relaxation of the packaging belt at the initial stage of starting. The torque feed can be estimated according to the width, thickness and roll diameter of the packaging belt and other parameters. Specifically, when the system starts or accelerates, the inertia of the entire motion system (including the packaging belt and the winding reel) must be overcome. The width and thickness of the packaging belt (combined with the material density) determine the mass per unit length of the belt. The greater the mass, the greater the force (tension) required during acceleration. The roll diameter determines the moment of inertia of the winding reel. A large roll diameter reel close to full winding has much greater moment of inertia than a small roll diameter reel close to empty core.

[0140] When estimating the torque feed, the estimation model will calculate the total inertia of the current system in real time according to these parameters, and estimate an acceleration torque as part of the feed.

[0141] In constant tension winding, the motor needs to apply torque, while the tension is the force acting on the surface of the reel. The relationship between the two is: torque = tension x reel radius.

[0142] As the roll diameter increases during winding, the motor output torque must also increase proportionally to maintain constant tension. The estimation model will continuously monitor the roll diameter and calculate the base torque required to maintain the target tension at the current roll diameter, which is also part of the feed.

[0143] Therefore, the tension control program in the PLC will integrate the above model to estimate a "torque feed" in advance according to the input parameters such as the width, thickness, material density of the packaging belt and the real-time monitored roll diameter. This torque feed is directly applied to the linear servo motor to quickly approach (even reach) the actual required value before the PID feedback controller starts to correct the error, thereby minimizing the relaxation or tension impact of the packaging belt at the initial stage of starting.

[0144] In addition, during the startup process, the tension value will not immediately reach the set value, but will gradually increase using a smooth ramp function. For example, within the first 2 seconds after startup, the tension value is linearly increased from 0 N to the target tension value (e.g., 100 N) to avoid sudden tension changes that could impact the packaging belt. During the startup phase, the proportional gain (Kp) and integral gain (Ki) of the PID controller can be set to relatively high values to improve the system's response speed and eliminate steady-state errors during the initial startup. For example, Kp can be set to 0.8 and Ki to 0.15, while the derivative gain (Kd) can be kept low or temporarily disabled to avoid excessive sensitivity to noise during the startup process. The speed correction parameters of the winding servo motor are also adjusted in coordination with the torque control parameters of the linear servo motor 21. This coordinated adjustment means that during the startup state, the parameters of the linear motor are set to force control priority, actively establishing tension, while the parameters of the winding motor are set to speed control following, passively adjusting the speed according to the displacement of the slider resulting from the operation of the linear motor. One is responsible for applying force, the other is responsible for matching speed, both are closely coordinated through the link of slider displacement information to complete a smooth startup process.

[0145] During the initial startup, the winding servo motor can start at a low initial speed and gradually accelerate based on the displacement feedback of the linear servo motor 21, ensuring that the tension of the packaging belt is within a controllable range.

[0146] When in the transition state, flexible adjustments can be made to avoid entering an abnormal state, for example: if the tension fluctuation amplitude slightly exceeds the stable threshold but does not reach the abnormal threshold, the system can start the flexible adjustment strategy. This strategy can include: first, reducing the proportional gain of the PID controller by 5% to reduce the system's reaction to tension errors and prevent excessive oscillation; second, increasing the integral gain by 2% to slowly eliminate steady-state errors and ensure that the tension eventually returns to the target value; at the same time, the speed correction parameters of the winding servo motor can be fine-tuned, for example, if the tension is too high, the winding speed can be slightly reduced by 0.1 meters / minute to reduce tension. These adjustments are gradual, and during the adjustment process, indicators such as tension fluctuation amplitude and displacement stability are continuously monitored. If the indicators continue to deteriorate and approach the abnormal threshold, higher-level intervention measures will be triggered.

[0147] When in the stable state, the optimal control parameters can be maintained. Thus, the overall performance, stability and reliability of the tension control system are significantly improved, effectively reducing the risk of excessive tension fluctuations, response delays or minor vibrations during the winding process of the belt material, thereby ensuring the constant tension winding quality of the packaging belt.

[0148] Traditional tension control systems often rely solely on preset thresholds for qualitative judgment when assessing the system performance level of the winding machine 1 under its current operating state. However, this qualitative assessment method struggles to accurately quantify the quality of system performance, especially under non-abnormal conditions. It fails to meticulously reflect the gap between system performance and the ideal state, potentially leading to an insufficient understanding of system performance and affecting the precise adjustment of subsequent torque control parameters and speed correction parameters. Therefore, further, step S34 includes:

[0149] S341: When the system is in a non-abnormal state, a set of ideal performance reference thresholds is preset for the current operating state of the winding machine 1;

[0150] S342: Calculate the tension fluctuation amplitude, tension response speed, displacement stability, and the degree of deviation of the strip's micro-vibration frequency from the ideal performance reference threshold;

[0151] S343: Determine the system performance level based on the degree of deviation.

[0152] Specifically, when the system is in a non-abnormal state, it means that the winding machine 1 is not judged to be in an abnormal state, i.e., the tension fluctuation amplitude does not exceed the preset abnormal threshold. For the current operating state of the winding machine 1, such as the start-up state, stable state, or transition state, a set of ideal performance reference thresholds needs to be preset. The ideal performance reference thresholds can be understood as the trend of the optimal or expected values ​​of key performance indicators such as tension fluctuation amplitude, tension response speed, displacement stability, and strip micro-vibration frequency changing with time or winding speed under a specific operating state. These curves can be obtained through historical data analysis. For example, after the winding machine 1 has undergone multiple adjustments and reached a good operating state, data such as tension fluctuation amplitude, tension response speed, displacement stability, and strip micro-vibration frequency under that state can be collected and stored. By performing statistical analysis on these historical data, such as calculating the average value and standard deviation, and combining it with time series analysis, ideal performance reference thresholds representing the "stable state" or "transition state" can be constructed. The purpose is to provide a benchmark for system performance evaluation.

[0153] The deviation degree refers to the difference between the actual measured tension fluctuation amplitude, tension response speed, displacement stability, and strip micro-vibration frequency and the ideal performance reference threshold under the corresponding running state. The deviation degree can be calculated by various mathematical methods, such as mean square error, absolute error, and percentage deviation, etc., the purpose of which is to quantify the gap between actual performance and ideal performance. For example, in a stable running state, the ideal tension fluctuation amplitude is 0.5N. If the actual measured tension fluctuation amplitude is 0.8N, the deviation degree can be calculated by the absolute error method: deviation degree = |0.8N-0.5N| = 0.3N. Or, by the percentage deviation method: deviation degree = ((0.8N-0.5N) / 0.5N)*100% = 60%. For multiple indicators, the deviation degree of each indicator can be calculated, and then a comprehensive deviation degree can be obtained by weighted average or maximum deviation, etc. For example, if the tension fluctuation amplitude deviates by 60%, the tension response speed deviates by 50%, the displacement stability deviates by 50%, and the strip micro-vibration frequency deviates by 40%, a comprehensive system performance deviation score can be calculated according to these deviation degrees, combined with the pre-set weights.

[0154] In practical application, the system performance level is determined according to the deviation degree, the smaller the deviation degree, the higher the system performance level, and vice versa. The system performance level can be divided into different levels, such as "excellent", "good", "general", and "poor", or represented by a continuous numerical value.

[0155] In some preferred embodiments, it is assumed that the winding machine 1 is currently in a stable state, and the ideal performance reference threshold in this stable state has been preset. The ideal performance reference threshold can be defined as: the tension fluctuation amplitude should be less than 0.5N, the tension response speed should be less than 0.2 seconds, the displacement stability (root mean square error) should be less than 0.1mm, and the strip micro-vibration frequency should be below 5Hz and the energy concentration should be less than 10%. In actual operation, the system obtains the current running data, and calculates that the tension fluctuation amplitude is 0.8N, the tension response speed is 0.3 seconds, the displacement stability is 0.15mm, the strip micro-vibration frequency is 7Hz, and the energy concentration is 15%. Next, the deviation degree is calculated. For example, the percentage deviation of each index from the ideal value can be calculated: the tension fluctuation amplitude deviation is 60%, the tension response speed deviation is 50%, the displacement stability deviation is 50%, and the strip micro-vibration frequency deviation is 40% (assuming that the energy concentration also deviates proportionally). According to these deviation degrees, the system performance level can be determined. For example, a comprehensive deviation index can be set, or each index can be rated according to its deviation degree. If the comprehensive deviation exceeds a certain threshold, the system performance level is determined to be “general” or “poor”; if the deviation is small, it is determined to be “good” or “excellent”. In this example, since each index deviates significantly, the system performance level may be determined to be “general”, indicating that there is some room for optimization. Through this quantitative evaluation, it can be clearly identified which performance indicators need to be adjusted and optimized first, thereby guiding the subsequent parameter adjustment strategy.

[0156] Further, step S4 comprises:

[0157] S41: According to the running state and the system performance level, the proportional gain, the integral gain and the differential gain of the PID controller, and the torque feedforward and the speed feedforward of the linear servo motor 21 are determined from the preset parameter mapping table;

[0158] S42: The proportional gain, the integral gain, the differential gain and the torque feedforward are collectively used as the torque control parameters of the linear servo motor 21, and the speed feedforward is used as the speed correction parameter of the winding servo motor.

[0159] Specifically, the running state and the system performance level refer to a comprehensive result obtained by evaluating the tension fluctuation amplitude, the tension response speed, the displacement stability, and the strip micro-vibration frequency, so as to represent the current working condition and the control effect of the coiler 1. The preset parameter mapping table can be understood as a data structure storing a plurality of sets of control parameters, wherein each set of parameters corresponds to a specific running state and system performance level. The mapping table can be a two-dimensional array, a hash table, or a database, the index of which can be a combination of the running state and the system performance level, and the corresponding value can be the proportional gain, the integral gain, and the differential gain of the PID controller, and the torque feedforward and the speed feedforward of the linear servo motor 21.

[0160] The proportional gain, the integral gain, and the differential gain of the PID controller are core parameters in the classical PID control algorithm, which are respectively used to adjust the response speed of the controller, eliminate the steady-state error, and suppress the overshoot. The torque feedforward and the speed feedforward of the linear servo motor 21 are important components in the feedforward control, which are used to apply a compensation control quantity in advance according to the known system model or experience before the system is disturbed, so as to improve the response speed and the anti-interference ability of the system. For example, the torque feedforward can adjust the output torque of the linear servo motor 21 according to the change of the winding speed and the winding diameter, and the speed feedforward can adjust the speed of the coiling servo motor according to the change of the winding speed.

[0161] The scheme of the present application solves the problem of insufficient adaptability of the traditional fixed parameters or simple calculation method under complex working conditions by introducing a preset parameter mapping table and dynamically selecting or determining the control parameters according to the real-time evaluated running state and system performance level.

[0162] Further, the step S41 comprises:

[0163] S411: continuously obtaining the running state and the system performance level during the operation of the coiler 1;

[0164] S412: judging whether the system performance level is lower than the preset optimization target;

[0165] S413: if the system performance level is lower than the optimization target, adjusting the parameter set corresponding to the current running state in the parameter mapping table according to the deviation degree of the system performance level from the optimization target;

[0166] S414: updating the adjusted parameter set to the parameter mapping table, and determining the proportional gain, the integral gain, and the differential gain of the PID controller, and the torque feedforward and the speed feedforward of the linear servo motor 21 from the updated parameter mapping table.

[0167] Specifically, in step S411, the running state and system performance level are continuously obtained according to the evaluation results of the above S3 step. This means that the system will monitor the running state of the winding machine 1 in real time, including the starting state, stable state, transition state and abnormal state, and evaluate its performance level. In step S412, the preset optimization target can be a specific performance indicator, such as a tension fluctuation amplitude less than a certain threshold, a tension response speed faster than a certain time, a displacement stability root mean square error less than a certain value, etc. When the system performance level is lower than the optimization target, it indicates that the current control parameters may no longer be the optimal choice and need to be adjusted. In step S413, the parameter mapping table is a lookup table that stores the corresponding PID parameters (proportional gain, integral gain, differential gain) and feedforward quantities (torque feedforward quantity, speed feedforward quantity) under different running states and system performance levels. When the system performance level is lower than the optimization target, the adjustment amount of the parameter set under the current running state will be calculated according to the deviation of the performance level from the optimization target, such as the deviation amplitude, duration, etc. This adjustment can be incremental or based on some optimization algorithm (such as gradient descent, genetic algorithm, etc.). In step S414, the adjusted parameter set is written or overwritten into the parameter mapping table, thereby realizing the dynamic updating of the parameter mapping table. Subsequently, the system will re-search and determine the parameters for controlling the linear servo motor 21 and the winding servo motor from the updated parameter mapping table according to the current running state and system performance level.

[0168] As a specific implementation, assume that the winding machine 1 is in a stable running state, and its tension fluctuation amplitude continuously exceeds the preset optimization target, for example, the target fluctuation amplitude is ±0.5N, but the actual fluctuation amplitude is ±0.8N. The system continuously obtains that the current is in the "stable state" and the "system performance level" is lower than the optimization target through step S411. In step S412, it is judged that the performance is indeed lower than the optimization target. Subsequently, in step S413, the system will fine-tune the PID proportional gain, integral gain, differential gain and torque feedforward quantity and speed feedforward quantity corresponding to the "stable state" in the parameter mapping table according to the deviation of 0.3N. For example, the proportional gain may be slightly increased to improve the response speed, and the integral gain is adjusted to eliminate the steady-state error. These adjusted parameter sets will be updated to the parameter mapping table in step S414. In the next control period, the system will obtain new parameters from the updated parameter mapping table to control the linear servo motor 21, so as to reduce the tension fluctuation amplitude to the optimization target range. This process can be continuously performed, so that the parameter mapping table can continuously learn and optimize over time and under varying working conditions, ensuring that the tension control system is always in a high-performance running state.

[0169] Further, step S413 comprises:

[0170] S4131: record the running state, system performance level, deviation degree, and historical parameter adjustment result, and construct a historical adjustment database;

[0171] S4132: according to the current running state and system performance level, retrieve similar historical data from the historical adjustment database;

[0172] S4133: combine the current deviation degree and the retrieved similar historical data, and adjust the parameter set corresponding to the current running state in the parameter mapping table.

[0173] Specifically, in step S4131, during the operation of the winding machine 1, the system continuously records key operating parameters, including the current operating state (such as start-up state, stable state, transition state, or abnormal state), the real-time evaluated system performance level, the deviation degree between the system performance level and the optimization target, and the specific adjustment result obtained after each parameter adjustment. These data are structured and stored to construct a historical adjustment database. The database can be implemented as a relational database, a non-relational database, or a file system, and its purpose is to accumulate rich historical experience data to provide a basis for subsequent intelligent adjustment.

[0174] In step S4132, when parameter adjustment is needed, the system retrieves from the constructed historical adjustment database according to the current running state of the winding machine 1 and the real-time evaluated system performance level as query conditions. The goal of the retrieval is to find the most similar historical data record to the current working condition. Similarity judgment can be based on various algorithms, such as Euclidean distance or cosine similarity, to ensure that the retrieved historical data can truly reflect the system behavior and adjustment effect similar to the current situation.

[0175] In actual application, in step S4133, after retrieving similar historical data, the system analyzes the current deviation degree with the deviation degrees and corresponding adjustment results recorded in these similar historical data. For example, weighted average, machine learning prediction, or expert system rules can be used to combine historical experience with current actual situation, thereby generating a more accurate and effective parameter adjustment strategy. Specifically, if a weighted average method is used, the system can assign different weights to the historical data according to the significance of the adjustment effect, the recency of the adjustment time, and other factors (wherein the recency refers to the time of recording the historical adjustment data. A data with high recency means it occurred very recently (e.g. a few minutes or hours ago); while a data with low recency may have been recorded a few days or months ago.), and then weightedly average these historical adjustment results to obtain a preliminary parameter adjustment suggestion.

[0176] Specifically, this weighted average process is an intelligent decision-making mechanism that aims to leverage historical experience comprehensively while prioritizing those that are most effective and relevant. It works as follows:

[0177] First, when a parameter adjustment is needed, the system retrieves a set of historical data with similar working conditions from the historical adjustment database based on the current operating state and performance level.

[0178] The system calculates a comprehensive weight value for each piece of retrieved historical data. This weight value is dynamically generated based on at least two factors, such as:

[0179] Compared to adjustments that only bring about minor improvements, historical adjustments that result in significant performance improvements (e.g., a 50% reduction in tension fluctuations) will receive higher weights.

[0180] Compared to adjustment data from last month, adjustments made yesterday will receive higher weights.

[0181] The system then performs a weighted average calculation. It multiplies the parameter adjustment result (e.g., "increase proportional gain by 5%") in each piece of historical data by its corresponding weight value. Then, it adds up all these weighted adjustment results and divides by the sum of all weight values.

[0182] The final result of this calculation is a preliminary parameter adjustment suggestion. This suggested value (e.g., "increase proportional gain by 4.8%") will be more inclined towards historical adjustment schemes that have been proven effective in recent times, thus avoiding being misled by outdated or ineffective historical data.

[0183] If a machine learning prediction approach is used, a regression model can be pre-trained with inputs such as operating state, system performance level, and deviation degree, and outputs as PID parameters and adjustment amounts for feedforward. When an adjustment is needed, the current working condition data is input into the model, which will predict the specific parameter adjustment value. For example, the model predicts that the proportional gain should be increased by 5.5% and the integral gain should be decreased by 2.1% under the current working condition.

[0184] If an expert system rule approach is used, a series of rules can be pre-set, such as "if in transition state and tension fluctuation amplitude deviation exceeds 20%, increase proportional gain by 5% and decrease integral gain." The system matches the corresponding rules based on the current working condition and performs the parameter adjustment operations defined in the rules.

[0185] This combination aims to avoid blind adjustment, but based on past successful experience and failure lessons, the parameter set corresponding to the current operating state in the parameter mapping table is optimized and adjusted. The parameter set usually includes the proportional gain, integral gain and differential gain of the PID controller, and the torque feedforward and speed feedforward of the linear servo motor 21.

[0186] Further, step S414 includes:

[0187] S4141: Taking the operating state and system performance level as the index, searching in the updated parameter mapping table to obtain the parameter value;

[0188] S4142: Interpolating the parameter value to obtain the proportional gain, integral gain and differential gain of the PID controller, and the torque feedforward and speed feedforward of the linear servo motor 21.

[0189] Specifically, in step S4141, the operating state and system performance level are used as the index of the parameter mapping table. The parameter mapping table can be constructed as a multi-dimensional lookup table, where one dimension corresponds to different operating states (such as start-up state, stable state, transition state, abnormal state), and the other dimension or multiple dimensions correspond to different intervals or specific values of system performance level. By inputting the current operating state and system performance level into the mapping table, one or more preset parameter sets closest to the current working condition can be quickly located, thereby obtaining the preliminary parameter value.

[0190] In step S4142, the parameter value obtained by searching is interpolated. Interpolation is a mathematical method for estimating the value of unknown data points between known data points. For example, when the system performance level is between two adjacent preset performance levels in the parameter mapping table, the more accurate proportional gain, integral gain and differential gain of the PID controller, and the torque feedforward and speed feedforward of the linear servo motor 21 under the current system performance level can be calculated by linear interpolation, polynomial interpolation or spline interpolation, etc. according to the parameter values corresponding to the two preset performance levels. The purpose is to realize continuous and refined adjustment of control parameters on the basis of discrete parameter mapping table, so as to better adapt to the continuously changing working conditions in actual operation.

[0191] The scheme of the present application solves the problem of inaccurate parameters caused by traditional discrete parameter lookup by introducing a lookup mechanism with operating state and system performance level as the index, and combining interpolation calculation. The above is only an embodiment of the present application and does not limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A tension structure for a linear servo motor, characterized in that, A linear servo motor tensioning structure is installed on the winding machine to adjust the tension of the strapping during the winding process, ensuring constant tension during winding. This structure includes at least the following: A linear servo motor includes at least a stator, a mover, and a linear motion module; the stator includes a high-precision magnetic levitation slide rail, on which a high-precision magnetic scale is configured; the mover includes a magnetic slider, which is movably mounted on the high-precision magnetic levitation slide rail and reciprocates along the high-precision magnetic levitation slide rail; the linear motion module includes at least a driver, which drives the magnetic slider to run on the high-precision magnetic levitation slide rail. A slider guide wheel is mounted on the magnetic slider. The packing strap moves with the magnetic slider through the slider guide wheel, thereby maintaining constant tension control. Tension control electrical control module: including at least a PLC controller, the PLC controller running a tension control program, the tension control program calculating the torque of the linear servo motor and the speed of the winding servo motor based on the slider displacement information of the slider guide wheel detected by the high-precision magnetic scale and the motor torque information of the linear servo motor, thereby controlling the tension balance of unwinding and winding.

2. A control method for a tension structure of a linear servo motor, characterized in that, The control method, applied to the linear servo motor tension structure as described in claim 1, includes the following steps: S1: Obtain the operating data of the linear servo motor tension structure, the operating data including at least motor torque information and slider displacement information; S2: Calculate the tension fluctuation amplitude and tension response speed based on the motor torque information; calculate the displacement stability of the slider guide wheel based on the slider displacement information; and identify the micro vibration frequency of the strip based on the motor torque information or the slider displacement information. S3: Based on the tension fluctuation amplitude, the tension response speed, the displacement stability, and the micro-vibration frequency of the strip, evaluate the performance of the tension control system and the dynamic characteristics of the strip, and obtain the evaluation results; S4: Based on the evaluation results, the torque control parameters of the linear servo motor and the speed correction parameters of the winding servo motor are calculated using the PID algorithm; S5: Control the linear servo motor to run according to the torque control parameters, and control the winding servo motor to run according to the speed correction parameters.

3. The control method for a linear servo motor tension structure according to claim 2, characterized in that, Step S2 includes: S21: Based on the motor torque information, obtain the strip tension data and calculate the standard deviation of the strip tension data as an indicator of the tension fluctuation amplitude; S22: Record the time required from the issuance of the tension control command to the time when the strip tension data reflected by the motor torque information reaches the preset percentage of the new target value, as an indicator of the tension response speed; S23: Based on the slider displacement information, obtain the slider guide wheel displacement and calculate the root mean square error of the slider guide wheel displacement as an indicator of displacement stability. S24: Perform spectrum analysis on the motor torque information or the slider displacement information to identify the frequency components with concentrated energy and obtain the micro vibration frequency of the strip.

4. The control method for a linear servo motor tension structure according to claim 2, characterized in that, Step S3 includes: S31: Define multiple operating states, including startup state, stable state, transition state and abnormal state; S32: Set an evaluation threshold for the operating state; S33: Based on the tension fluctuation amplitude, the tension response speed, the displacement stability, and the micro-vibration frequency of the strip, determine the current operating status of the winding machine according to the evaluation threshold; S34: Assess the system performance level of the winding machine under its current operating condition; S35: The operating status and the system performance level are used as the evaluation results.

5. The control method for a linear servo motor tension structure according to claim 4, characterized in that, Step S33 includes: S331: If the tension fluctuation exceeds its corresponding preset abnormal threshold, the winding machine is determined to be in an abnormal state; otherwise, it is not in an abnormal state. S332: If not in an abnormal state, obtain the winding speed of the winding machine. If the winding speed is lower than the preset start-up completion speed and the tension response speed is higher than the preset response threshold, it is determined to be in the start state; otherwise, it is not in the start state. S333: If not in the start-up state, determine whether any of the following indicators exceeds the corresponding preset stability threshold: tension fluctuation amplitude, displacement stability, and strip micro-vibration frequency. If it exceeds the corresponding preset stability threshold but does not reach the corresponding preset abnormal threshold, determine that the winding machine is currently in a transition state; if it does not exceed the corresponding preset stability threshold, determine that the winding machine is currently in a stable state.

6. The control method for a linear servo motor tension structure according to claim 5, characterized in that, Step S34 includes: S341: When the system is in a non-abnormal state, a set of ideal performance reference thresholds is preset for the current operating state of the winding machine; S342: Calculate the tension fluctuation amplitude, the tension response speed, the displacement stability, and the deviation of the micro-vibration frequency of the strip from the ideal performance reference threshold; S343: Determine the system performance level based on the degree of deviation.

7. The control method for a linear servo motor tension structure according to claim 4, characterized in that, Step S4 includes: S41: Based on the operating status and the system performance level, determine the proportional gain, integral gain, and derivative gain of the PID controller, as well as the torque feedforward and speed feedforward of the linear servo motor from the preset parameter mapping table; S42: The proportional gain, the integral gain, the differential gain, and the torque feedforward are used together as the torque control parameters of the linear servo motor, and the speed feedforward is used as the speed correction parameter of the winding servo motor.

8. The control method for a linear servo motor tension structure according to claim 7, characterized in that, Step S41 includes: S411: During the operation of the winding machine, the operating status and the system performance level are continuously acquired; S412: Determine whether the system performance level is lower than the preset optimization target; S413: If the system performance level is lower than the optimization target, then the parameter set corresponding to the current operating state in the parameter mapping table is adjusted according to the degree of deviation between the system performance level and the optimization target; S414: Update the adjusted parameter set to the parameter mapping table, and determine the proportional gain, integral gain, and derivative gain of the PID controller, as well as the torque feedforward and speed feedforward of the linear servo motor from the updated parameter mapping table.

9. The control method for a linear servo motor tension structure according to claim 8, characterized in that, Step S413 includes: S4131: Record the operating status, system performance level, degree of deviation, and historical parameter adjustment results to build a historical adjustment database; S4132: Based on the current operating status and the system performance level, retrieve similar historical data from the historical adjustment database; S4133: Based on the current degree of deviation and the retrieved similar historical data, adjust the parameter set corresponding to the current running state in the parameter mapping table.

10. The control method for a linear servo motor tension structure according to claim 8, characterized in that, Step S414 includes: S4141: Using the operating status and the system performance level as indexes, search in the updated parameter mapping table to obtain the parameter value; S4142: Interpolate the parameter values ​​to obtain the proportional gain, integral gain, and derivative gain of the PID controller, as well as the torque feedforward and speed feedforward of the linear servo motor.

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