Rolling diameter calculation method for high-speed and wide battery pole piece equipment

Abstract

The invention relates to the technical field of automatic control, and discloses a roll diameter calculation method for high-speed and wide battery pole piece equipment, and a system comprises an unwinding unit, a metering roller unit, a winding unit, an unwinding encoder, a metering encoder, a winding encoder and a controller, and the unwinding encoder, the metering encoder and the winding encoder are respectively connected with an unwinding shaft, a metering roller and a winding shaft. The method comprises the following steps: synchronously obtaining the angle increment of each shaft and the length increment of a material; calculating a stable rolling diameter through a symmetric differential model based on the incremental data; generating a characterization variable for quantifying the stretching state of the material as process feedback; an adjustment signal is generated in a closed loop without a physical sensor and used to dynamically correct the drive command. High-precision rolling diameter calculation and self-adaptive tension closed-loop control are achieved through a pure algorithm, a physical tension sensor is replaced, the equipment cost and the maintenance difficulty are remarkably reduced, and the system operation stability and the final product quality are improved.

Description

Technical Field

[0001] This invention relates to the field of automation control technology, specifically to a method for calculating the roll diameter of high-speed and wide-width battery electrode equipment. Background Technology

[0002] In the high-speed winding production of roll materials such as battery electrodes, films, paper, and textiles, precise control of material tension is a key technical aspect to ensure product quality and production stability. Unstable tension can lead to material wrinkles, tensile deformation, or even breakage, directly affecting the final product's yield rate.

[0003] Traditional tension control systems typically rely on physical tension sensors, such as pressure sensors or tension gauges, installed on the production line to directly measure the real-time tension of the material and use this as a feedback signal for closed-loop control. However, these physical sensors are expensive, increasing the manufacturing cost of the equipment and the complexity of the system. Furthermore, they require high installation accuracy and are prone to measurement drift due to mechanical wear or fatigue during long-term operation, necessitating regular calibration and maintenance. In harsh environments such as battery electrode production, where dust and chemical corrosion are present, the reliability and lifespan of physical sensors face severe challenges, and their failure can directly lead to production interruptions.

[0004] To compensate for the limitations of physical sensors, the industry has also explored indirect tension control methods based on roll diameter. This method requires real-time acquisition of the diameter of the winding and unwinding roll. Existing roll diameter measurement technologies mainly rely on external non-contact sensors, such as ultrasonic sensors or laser displacement sensors, to detect the surface position of the roll and calculate the diameter. While this method avoids direct contact with the material, its measurement accuracy is highly susceptible to interference from uneven roll end faces, winding skew, and environmental factors such as dust and smoke, leading to jumps or inaccuracies in the roll diameter data, thus affecting the stability of tension control. In addition, some methods exist that estimate the diameter using internal parameters of the actuator, but their accuracy often falls short of the requirements for high-precision control.

[0005] Therefore, this invention proposes a method for calculating the roll diameter of high-speed and wide-width battery electrode equipment to address the shortcomings of existing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for calculating the roll diameter of high-speed and wide-width battery electrode equipment. This method solves the problem of achieving high-precision and high-reliability adaptive tension control of the roll material winding process without relying on expensive and easily damaged physical tension sensors or external roll diameter sensors that are susceptible to environmental interference.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for calculating the roll diameter of high-speed and wide-width battery electrode equipment, the method comprising the following steps:

[0008] S1. In each control cycle, the unwind encoder, the metering encoder and the winding encoder are used to synchronously acquire the angle increment of the unwinding shaft, the linear length increment of the material and the angle increment of the winding shaft.

[0009] S2. Based on the kinematic differential relationship between the linear length increment of the material and the angle increment of the unwinding and rewinding shafts, a symmetrical differential algorithm model is applied for real-time calculation to determine the stable unwinding diameter and stable rewinding diameter corresponding to the physical state of the winding equipment.

[0010] S3. Based on the determined stable unwinding diameter and stable winding diameter, establish a quantitative evaluation model for online diagnosis of material physical integrity, and convert the dynamic mismatch between the theoretical absorption arc length calculated based on the winding side geometric parameters and the theoretical unwinding arc length calculated based on the unwinding side geometric parameters into a tensile characterization variable that can quantitatively characterize the physical tensile state of the material.

[0011] S4. In a closed-loop control loop without a physical tension sensor, the tensile characterization variable is used as the only process feedback signal characterizing the actual material tension, and is compared in real time with the target set point of zero tension state to generate a tension adjustment signal for actively compensating for tension changes.

[0012] S5. The tension adjustment signal is used to dynamically correct the drive command of the unwinding or rewinding shaft, thereby forming an adaptive tension closed-loop control in the winding equipment that is not dependent on physical measurement hardware and is driven by an algorithm.

[0013] Preferably, in step S1, the step of simultaneously acquiring the angle increment of the unwinding shaft, the linear length increment of the material, and the angle increment of the rewinding shaft includes:

[0014] Based on the physical dimensions of the metering rollers installed on the metering encoders and the pulse resolution of each encoder, the conversion coefficients are pre-configured;

[0015] The conversion coefficients are used to convert the raw pulse counts collected by the unwind encoder, metering encoder, and winding encoder during the control cycle into the angle increment of the unwind shaft, the linear length increment of the material, and the angle increment of the winding shaft, respectively.

[0016] Preferably, in step S2, the step of applying a symmetric differential algorithm model for real-time calculation based on the kinematic differential relationship between the linear length increment of the material and the angular increments of the unwinding and rewinding shafts includes:

[0017] Determine whether the absolute values ​​of the angle increments of the unwinding shaft and the winding shaft are greater than a preset threshold. If the determination result is yes, then use the linear length increment of the material, the angle increment of the unwinding shaft, and the angle increment of the winding shaft to calculate the instantaneous radius of the unwinding side and the instantaneous radius of the winding side using the following formula:

[0018]

[0019] In the formula, r A,inst r is the instantaneous radius on the unwinding side. C,inst ΔL is the instantaneous radius on the winding side; B Δθ represents the linear length increment of the material. A Δθ is the angle increment of the unwinding spool. C This is the angle increment of the rewind spool.

[0020] Preferably, in step S2, the symmetric differential algorithm model is applied for real-time solution, specifically including:

[0021] The instantaneous radii of the unwinding side and the instantaneous radii of the winding side, determined by the calculation formulas of the instantaneous radii of the unwinding side and the instantaneous radii of the winding side, are used as inputs and smoothed by an exponential moving average filter to obtain stable unwinding diameter and stable winding diameter.

[0022] Preferably, in step S3, the step of establishing a quantitative assessment model for online diagnosis of material physical integrity based on the determined stable unwinding diameter and stable winding diameter includes:

[0023] The quantitative evaluation model converts the dynamic mismatch into a stretching characterization variable using the following formula:

[0024]

[0025] In the formula, ε is the stretching characterization variable; For the theoretical absorption arc length; For the theoretical solution of the arc length; D A (k) is the stable unwinding diameter for the current control cycle; D C (k) is the stable winding diameter for the current control cycle; Δθ A Δθ is the angle increment of the unwinding spool. C This is the angle increment of the rewind spool.

[0026] Preferably, the quantitative evaluation model further includes determining the physical state of the stretching characterization variables:

[0027] When the value of the stretching characterization variable ε is positive, it is determined that the material has been overstretched;

[0028] When the value of the tensile characterization variable ε is negative, it is determined that the material has relaxed or slipped.

[0029] Preferably, in step S4, the step of using the tensile characterization variable as the sole process feedback signal characterizing the actual material tension in a closed-loop control loop without a physical tension sensor, and comparing it in real time with the target setpoint of zero tension state, includes:

[0030] In a PID controller, the stretching characterization variable is assigned to the process variable, and the target setpoint of the zero stretching state is assigned to the setpoint.

[0031] The PID controller generates the tension adjustment signal based on the deviation between the process variable and the set value using a PID algorithm.

[0032] Preferably, step S5, which involves dynamically correcting the drive command of the unwinding or rewinding shaft using the tension adjustment signal, includes:

[0033] The tension adjustment signal is used as a speed compensation value or torque compensation value to dynamically superimpose and correct the basic speed command or basic torque command of the unwinding shaft and the winding shaft respectively.

[0034] Preferably, the method further includes:

[0035] Based on the material cross-sectional area conservation relationship, and using the stable unwinding diameter and preset material thickness, the remaining length of the material is calculated.

[0036] The total length of the processed material is calculated by summing the linear length increments of the material measured in each control cycle.

[0037] The present invention also provides a roll diameter calculation system for high-speed and wide-width battery electrode equipment, the system comprising:

[0038] The acquisition unit includes an unwind encoder, a metering encoder, and a winding encoder. The acquisition unit is used to synchronously acquire the angle increment of the unwinding shaft, the linear length increment of the material, and the angle increment of the winding shaft in each control cycle.

[0039] The roll diameter calculation unit is used to perform real-time calculations based on the linear length increment of the material and the angle increments of the unwinding and rewinding shafts, using a symmetrical differential algorithm model, to determine a stable unwinding diameter and a stable rewinding diameter.

[0040] The diagnostic variable generation unit is used to convert the dynamic mismatch between the theoretical absorption arc length calculated based on the geometric parameters of the winding side and the theoretical unwinding arc length calculated based on the geometric parameters of the unwinding side into a stretching characterization variable through a quantitative evaluation model, based on the determined stable unwinding diameter and stable winding diameter.

[0041] The closed-loop adjustment signal generation unit is used to compare the tension characterization variable as a process feedback signal with the target set point of zero tension state in a closed-loop control loop without a physical tension sensor to generate a tension adjustment signal.

[0042] The drive command correction unit is used to dynamically correct the drive command of the unwinding or rewinding shaft using the tension adjustment signal, so as to form an algorithm-driven adaptive tension closed-loop control.

[0043] This invention provides a method for calculating the roll diameter of high-speed and wide-width battery electrode equipment. It offers the following advantages:

[0044] 1. This invention uses a symmetrical differential algorithm model to calculate the angle and length increments obtained synchronously by three encoders at the unwinding, metering, and rewinding points. This method is based on the inherent kinematic relationship of the material, rather than external physical detection. Compared with traditional methods that rely on ultrasonic or laser sensors, this invention fundamentally avoids measurement errors caused by physical disturbances such as uneven roll end faces, centrifugal shaking, or on-site dust, especially under high-speed and wide-width operating conditions, ensuring the stability and accuracy of the roll diameter calculation results.

[0045] 2. This invention establishes a quantitative evaluation model to convert the calculated stable roll diameter into a tensile characterization variable that can directly characterize the physical tensile state of the material, and uses this variable as the sole process feedback signal for closed-loop control. This design replaces the traditional solution that requires the installation of expensive and easily damaged physical tension sensors, not only reducing the hardware and maintenance costs of the equipment, but also simplifying the hardware structure of the control system and reducing potential failure points.

[0046] 3. In the production process of high-speed and wide-width battery electrodes, even minute fluctuations in material tension can be amplified. This invention, through algorithm-driven adaptive tension closed-loop control, can diagnose dynamic mismatch of materials in real time for each control cycle and dynamically correct the drive commands of the unwinding or rewinding shafts in an instant. This rapid response mechanism can proactively compensate for tension fluctuations caused by speed changes or uneven material properties, ensuring the dynamic stability of the entire winding process.

[0047] 4. Based on the aforementioned precise roll diameter calculation and stable tension control, this invention can effectively avoid quality defects such as electrode wrinkling and excessive stretching deformation caused by uneven or drastic tension fluctuations, ensuring coating consistency and the final product's pass rate. Simultaneously, precise roll diameter data provides a reliable basis for stable equipment speed control, while stable tension significantly reduces the risk of material breakage due to uncontrolled tension, thereby reducing unplanned downtime and material waste, and improving the overall operating efficiency of the equipment. Attached Figure Description

[0048] Figure 1 This is a hardware structure block diagram of the roll diameter calculation and control system of the present invention;

[0049] Figure 2 This is a flowchart illustrating the overall logic of the method of the present invention.

[0050] Figure 3 This is a schematic diagram illustrating the kinematic relationship between the unwinding shaft, the metering roller, and the take-up shaft of the present invention.

[0051] Figure 4 A schematic diagram illustrating the effect of filtering the instantaneous radius data according to the present invention;

[0052] Figure 5 This is a schematic diagram of the sensorless adaptive tension closed-loop control loop of the present invention.

[0053] The components include: 1. Unwinding unit; 11. Unwinding shaft; 12. Unwinding encoder; 2. Metering roller unit; 21. Metering roller; 22. Metering encoder; 3. Winding unit; 31. Winding shaft; 32. Winding encoder; 4. Material; 5. Controller; 6. Drive system; 51. Acquisition unit; 52. Roll diameter calculation unit; 53. Diagnostic variable generation unit; 54. Closed-loop adjustment signal generation unit; and 55. Drive command correction unit. Detailed Implementation

[0054] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] See attached document Figure 1 , Figure 1 This is a hardware structure block diagram of a roll diameter calculation and control system according to an embodiment of the present invention. The system is applied to the winding operation of high-speed and wide-width battery electrode equipment, and its physical structure includes an unwinding unit 1, a metering roller unit 2, a winding unit 3, a controller 5, and a drive system 6.

[0056] In one specific embodiment, the unwinding unit 1 is provided with an unwinding shaft 11 for carrying the rolled material 4 to be processed. The winding unit 3 is provided with a winding shaft 31 for winding up the processed material 4. The metering roller unit 2 is disposed between the unwinding unit 1 and the winding unit 3, and includes a metering roller 21. After the material 4 is unwound from the unwinding shaft 11, it passes through the metering roller 21 and is then wound up by the winding shaft 31.

[0057] An unwind encoder 12 is coaxially connected to the unwind shaft 11. A metering encoder 22 is coaxially connected to the metering roller 21. A take-up encoder 32 is coaxially connected to the take-up shaft 31. These three encoders are used to accurately measure the rotation angle of the unwind shaft 11, the rotation angle of the metering roller 21, and the rotation angle of the take-up shaft 31, respectively.

[0058] Controller 5, such as a programmable logic controller (PLC) or motion controller, is connected via signal cables to unwind encoder 12, metering encoder 22, and take-up encoder 32 to receive pulse signals output from these three encoders. Controller 5 is also connected to drive system 6, which drives the motors of unwind shaft 11 and take-up shaft 31 to rotate, respectively. Controller 5 controls the operating speed or output torque of unwind shaft 11 and take-up shaft 31 by sending drive commands to drive system 6.

[0059] See attached document Figure 2 , Figure 2 This is an overall logic flowchart of a roll diameter calculation method according to an embodiment of the present invention. The roll diameter calculation and control method provided by the present invention is executed by a controller 5, which integrates an acquisition unit 51, a roll diameter calculation unit 52, a diagnostic variable generation unit 53, a closed-loop adjustment signal generation unit 54, and a drive command correction unit 55.

[0060] The execution flow of this method is as follows:

[0061] In step S1, the acquisition unit 51 in the controller 5 synchronously acquires the angle increment of the unwinding shaft 11, the linear length increment of the material 4, and the angle increment of the winding shaft 31 through the unwinding encoder 12, the metering encoder 22, and the winding encoder 32 in each control cycle.

[0062] In step S2, the roll diameter calculation unit 52 receives the three incremental data obtained in step S1. Based on the inherent kinematic differential relationship between the linear length increment of material 4 and the angular increments of unwinding shaft 11 and winding shaft 31, a symmetric differential algorithm model is applied for real-time calculation to determine a stable unwinding diameter and a stable winding diameter corresponding to the current physical state of the roll.

[0063] In step S3, the diagnostic variable generation unit 53 receives the stable unwinding diameter and stable winding diameter determined in step S2. Based on these two diameter data, a quantitative evaluation model is used to calculate the dynamic mismatch between the material length theoretically unwound by the unwinding shaft 11 and the material length theoretically absorbed by the winding shaft 31, and this mismatch is converted into a tensile characterization variable that can quantitatively characterize the physical tensile state of the material 4.

[0064] In step S4, the closed-loop adjustment signal generation unit 54 operates in a closed-loop control loop without a physical tension sensor. This unit uses the tensile characterization variable generated in step S3 as the sole process feedback signal characterizing the actual material tension, and compares it in real time with a preset target setpoint of zero tension. Based on the deviation of the comparison, it generates a tension adjustment signal for actively compensating for tension changes.

[0065] In step S5, the drive command correction unit 55 receives the tension adjustment signal generated in step S4. This unit uses this signal to dynamically correct the drive commands sent to the drive system 6 for the unwinding shaft 11 or the take-up shaft 31. Thus, an adaptive tension closed-loop control, entirely algorithm-driven and independent of physical measurement hardware, is formed throughout the winding equipment.

[0066] See attached document Figure 1 and attached Figure 3 , Figure 1 This is a system hardware structure block diagram according to an embodiment of the present invention. Figure 3 This diagram illustrates the kinematic relationships between the axes. The first step of the method is explained in detail below.

[0067] The goal of this step is to accurately and synchronously acquire the angular increments of the unwinding shaft 11 and the rewinding shaft 31, as well as the linear length increment of the material 4, within each control cycle. This function is implemented by the acquisition unit 51 within the controller 5.

[0068] To ensure strict consistency of data acquisition in terms of time reference, controller 5 utilizes its internal high-speed hardware counter channels and a unified system clock. In one specific implementation, controller 5 is configured with a periodic interrupt, the period of which is the system control cycle T. At the start of each interrupt service routine, controller 5 generates an internal synchronization latch signal, which is simultaneously sent to the three high-speed counter channels connecting the unwind encoder 12, the metering encoder 22, and the take-up encoder 32, to lock and read the pulse count values ​​of each channel at the same instant. By calculating the difference between the current latch value and the latch value of the previous cycle, the original pulse increment output by each of the three encoders within that control cycle can be obtained.

[0069] The obtained raw pulse increments do not have direct physical meaning and need to be converted into engineering units through a pre-set conversion factor. This conversion factor is configured during system initialization based on the physical resolution of the encoder and the precise geometric dimensions of the metering roller 21 and is stored in the memory of the controller 5.

[0070] Within one control cycle, the acquisition unit 51 converts the acquired raw pulse count into a physical increment using the following relationship:

[0071]

[0072] In the formula, Δθ A The angular increment of the unwinding shaft 11 within the control cycle, expressed in radians (rad); N A P represents the number of raw pulses acquired by the unwind encoder 12 during this control cycle. A Δθ is the total number of pulses output by the unwind encoder 12 per revolution. C N represents the angular increment of the take-up shaft 31 within the control cycle, in radians (rad); C P represents the number of raw pulses acquired by the take-up encoder 32 during this control cycle. C ΔL is the total number of pulses output by the take-up encoder 32 per revolution; B N represents the linear length increment of material 4 within the control period, in meters (m); B D represents the number of raw pulses collected by the metering encoder 22 during this control cycle. B P is the physical diameter of the metering roller 21, which needs to be precisely measured to ensure accuracy; the unit is meters (m). B This is the total number of pulses output by the encoder 22 for each revolution.

[0073] See attached document Figure 3 , Figure 3 This is a schematic diagram illustrating the kinematic relationship between the unwinding shaft 11, the metering roller 21, and the take-up shaft 31, as per the present invention. The synchronous unwinding shaft angle increment Δθ is obtained. A Increment of take-up axis angle Δθ C and the linear length increment ΔL of the material B Then, the roll diameter calculation unit 52 in the controller 5 begins to perform the calculation for this step.

[0074] The calculation in this step is based on a fundamental kinematic principle: Under ideal conditions, i.e., when material 4 has no slippage and no physical stretching or shrinkage, within one control cycle, the arc length of the material unwound from the surface of the unwound roll and the arc length absorbed by the surface of the rewound roll should both be equal to the linear length increment ΔL of material 4 measured by the metering roller 21 during the same period. BBased on this relationship, the instantaneous radii of the unwinding side and the winding side can be calculated separately.

[0075] The formulas for calculating the instantaneous radius on the unwinding side and the instantaneous radius on the winding side are as follows:

[0076]

[0077] In the formula, r A,inst r is the instantaneous radius calculated on the unwinding side within one control cycle, in meters (m); C,inst ΔL is the instantaneous radius calculated on the take-up side within one control cycle, in meters (m); B Δθ represents the linear length increment of the material, in meters (m); A Δθ represents the angular increment of the unwinding spool, in radians (rad); C This represents the angular increment of the rewind spool, in radians (rad).

[0078] Before applying the above formula for calculation, the roll diameter calculation unit 52 also includes a step to determine the validity of the denominator. Specifically, it determines the angle increment Δθ of the unwinding axis. A The angle increment Δθ of the take-up axis C Is the absolute value greater than a preset minimum threshold (e.g., 1×10)? -6 (rad). The instantaneous radius is calculated only when the absolute value of the angle increment is greater than this threshold. If the angle increment is less than or equal to this threshold, the calculation is abandoned for this control cycle, and the stable diameter value D from the previous cycle is used. stable (k-1) is the stable diameter value D for the current period. stable (k). This step can effectively avoid system errors caused by the denominator being zero due to the equipment being stationary or crawling at extremely low speed.

[0079] In real industrial environments, the high-speed operation of equipment generates mechanical vibrations. Additionally, the encoder signal itself exhibits minute electrical jitter, and the digital control system inherently contains discretization errors. Therefore, the instantaneous radius value r calculated directly using the above formula becomes problematic. A,inst and r C,inst It will contain high-frequency noise, the value of which will fluctuate around the true value. If this noisy data is used directly for subsequent control, it will lead to instability in the control output.

[0080] See attached document Figure 4 , Figure 4This diagram illustrates the effect of filtering instantaneous radius data. In the diagram, the dashed line represents the instantaneous diameter value calculated from the instantaneous radius, which contains noise and exhibits irregular fluctuations. To eliminate this noise interference and obtain a stable diameter that accurately reflects the physical dimensions of the roll, the roll diameter calculation unit 52 filters the calculated instantaneous diameter (twice the instantaneous radius). The solid line in the diagram represents the stable diameter value output after filtering, whose trend is smooth and accurately tracks the continuous change in the roll diameter.

[0081] In one specific implementation, an exponential moving average (EMA) filter is used to smooth the instantaneous diameter data. This filter is chosen because of its low computational cost and small storage space requirement, making it suitable for control systems with real-time requirements. The filtering algorithm performs separate calculations for the instantaneous diameters on the unwinding and rewinding sides, and the formula is as follows:

[0082] D stable (k)=α·(2·r inst (k))+(1-α)·D stable (k-1);

[0083] In the formula, D stable (k) is the stable diameter (D on the unwinding side) calculated in the current k-th control cycle. A (k) or D on the winding side C (k)), the unit is meters (m); r inst (k) is the instantaneous radius calculated in the current k-th control cycle (r on the unwinding side). A,inst or the r on the winding side C,inst ), the unit is meters (m); D stable (k-1) is the stable diameter determined in the previous control cycle (k-1th cycle). A preset core diameter can be used as the initial value during the first calculation. α is the filtering coefficient, a preset constant between 0 and 1 (e.g., 0.1). This coefficient determines the weighting relationship between the current measurement value and the historical average. A smaller α value produces a smoother output but a slower response to actual diameter changes; a larger α value results in a faster response but a weaker smoothing effect.

[0084] The exponential moving average filter is a preferred implementation. In other embodiments, other digital filters with data smoothing capabilities, such as the simple-moving-average (SMA) filter or the weighted-moving-average (WMA) filter, can also be used to smooth noisy instantaneous diameter data to obtain a stable diameter output.

[0085] With a stable unwinding diameter D at the output A (k) and stable winding diameter D C (k) After that, the diagnostic variable generation unit 53 in the controller 5 executes this step. The purpose of this step is to convert the calculation results of the geometric dimensions into quantitative indicators that can directly characterize the physical tensile state of material 4.

[0086] The underlying principle is as follows: based on the stable roll diameter and angle increment of the current control cycle, the theoretical material unwinding length and the theoretical material absorption length are calculated respectively. The theoretical unwinding length refers to the arc length of material that should be released from the surface of the unwinding shaft 11 according to the geometric parameters of the unwinding side. The theoretical absorption length refers to the arc length of material that should be wound onto the surface of the take-up shaft 31 according to the geometric parameters of the take-up side.

[0087] In an ideal transmission process where the physical properties of material 4 remain constant, these two theoretical length values ​​should be equal. However, in actual operation, due to tension variations causing elastic deformation of the material, a dynamic difference will arise between the two theoretically calculated lengths; this difference is called dynamic mismatch. The magnitude and sign of this dynamic mismatch directly and quantitatively reflect the physical tension or relaxation state of the material in the region between the unwinding shaft 11 and the rewinding shaft 31. This dynamic mismatch is defined as a tension characterization variable.

[0088] Among them, the product term This represents the theoretical absorption arc length calculated based on the geometric parameters of the winding side, while the product term... This represents the theoretical unwinding arc length calculated based on the unwinding side geometry. The stretching characterization variable is the difference between these two theoretical arc lengths.

[0089] The tensile characterization variable is calculated using the following formula:

[0090]

[0091] In the formula, ε(k) is the stretching characterization variable calculated in the current k-th control cycle, and its unit is meters (m), representing a length difference; D A (k) represents the stable unwinding diameter for the current control cycle, in meters (m); D C (k) is the stable winding diameter for the current control cycle, in meters (m); Δθ A (k) represents the unwinding axis angle increment for the current control cycle, in radians (rad); Δθ C (k) represents the rewind axis angle increment for the current control cycle, in radians (rad).

[0092] The calculated result of the tensile characterization variable ε(k) has a clear physical meaning and is used to determine the state of the material:

[0093] When ε(k) is positive, it indicates that the theoretical absorption length is greater than the theoretical unwinding length. This indicates that the material is stretched between unwinding and rewinding, and the system determines that material 4 has been overstretched.

[0094] When ε(k) is negative, it indicates that the theoretical absorption length is less than the theoretical unwinding length. This suggests that a margin has been created between unwinding and rewinding, and the system determines that material 4 has become slack or slipped on a certain drive roller.

[0095] When the value of ε(k) is within a very small threshold range near zero, it indicates that the theoretical unwinding length and the theoretical absorption length are basically in balance, and the system determines that material 4 is in an ideal zero tensile transfer state.

[0096] See attached document Figure 5 , Figure 5 This is a schematic diagram of the sensorless adaptive tension closed-loop control loop constructed in this invention. After the diagnostic variable generation unit 53 calculates the tension characterization variable ε(k), the closed-loop adjustment signal generation unit 54 in the controller 5 performs the calculation in this step, the purpose of which is to generate a tension adjustment signal for actively compensating for tension changes.

[0097] like Figure 5 As shown, this step constructs a closed-loop control loop. Unlike traditional tension control systems, this loop does not rely on any physical tension measurement hardware. The tensile characterization variable ε(k), calculated in step S3 and capable of quantifying the material's physical tensile state, is used as the process variable (PV) of this closed-loop control loop. The goal of this loop is to maintain the material in an ideal zero tensile transfer state; therefore, a constant zero value is used as the target setpoint (SP) of the loop.

[0098] In one specific implementation, the closed-loop controller employs a PID algorithm. In other embodiments, depending on the different requirements for control accuracy and response speed, a proportional-integral (PI) controller can also be used. The PI controller generates a tension adjustment signal based on the proportional and integral terms of the deviation; its structure is simpler, and it can achieve stable control performance under many operating conditions.

[0099] In each control cycle, the closed-loop control signal generation unit 54 first calculates the deviation between the process variable and the target setpoint. Then, a PID (Proportional-Integral-Derivative) controller generates a control output based on this deviation value through its internal algorithm. This output is the tension adjustment signal.

[0100] In one specific implementation, to avoid integral saturation and ensure smooth control output changes, an incremental discrete PID algorithm is used. This algorithm calculates not the absolute value of the control quantity, but the increment value for each cycle.

[0101] First, calculate the control deviation for the current control cycle:

[0102] e(k)=SP-PV(k)=0-ε(k)=-ε(k);

[0103] Based on this deviation value, the PID controller calculates the increment Δu(k) of the tension adjustment signal for the current cycle, using the following formula:

[0104] Δu(k)=K p ·(e(k)-e(k-1))+K i ·e(k)+K d ·(e(k)-2e(k-1)+e(k-2));

[0105] After obtaining the increment, update the final tension adjustment signal u(k):

[0106] u(k) = u(k-1) + Δu(k);

[0107] In the formula, u(k) is the tension adjustment signal finally generated in the current k-th control cycle; Δu(k) is the increment of the tension adjustment signal calculated in the current k-th control cycle; u(k-1) is the tension adjustment signal generated in the previous control cycle (k-1-th cycle); e(k) is the control deviation in the current k-th cycle, with a value of -ε(k); e(k-1) is the control deviation in the previous cycle; e(k-2) is the control deviation in the cycle before that; K p K is the proportional gain coefficient of the PID controller. i K is the integral gain coefficient of the PID controller. d This represents the differential gain coefficient of the PID controller.

[0108] These three gain coefficients are preset parameters, and their values ​​are adjusted according to the dynamic response characteristics of the specific device.

[0109] After generating the tension adjustment signal u(k), the drive command correction unit 55 within the controller 5 executes this step. The purpose of this step is to apply the tension adjustment signal to the drive system 6 to dynamically correct the drive commands of the unwinding shaft 11 or the take-up shaft 31 in real time, thereby forming a complete, algorithm-driven adaptive tension closed-loop control.

[0110] Dynamic correction can be applied to the drive commands of the take-up spool 31, the unwind spool 11, or both simultaneously with a certain allocation relationship. The following explanation uses the correction of the drive commands of the take-up spool 31 as an example.

[0111] The tension adjustment signal u(k) is a dynamic, quantified compensation value, and its specific application depends on the control mode of the drive system 6. Two specific modification implementation methods are described below.

[0112] First implementation method (based on speed difference command modification):

[0113] In scenarios where the winding system employs a master-slave speed control mode, the speed command of the driven shaft (usually the take-up shaft 31) can be dynamically superimposed and corrected using the tension adjustment signal u(k). First, the system adjusts the speed based on the set master linear speed V. set Based on the calculated stable roll diameter, the base angular velocity commands for the unwinding shaft 11 and the take-up shaft 31 are calculated. Subsequently, the tension adjustment signal u(k) is superimposed on the speed command of the take-up shaft 31 as a speed compensation amount.

[0114] The final angular velocity command sent to the take-up shaft driver is calculated using the following formula:

[0115] ω C,cmd (k)=ω C,base (k)+u(k);

[0116] in,

[0117]

[0118] In the formula, ω C,cmd (k) represents the angular velocity command finally issued to the take-up shaft drive system in the current k-th control cycle, in radians per second (rad / s); ω C,base (k) is the basic angular velocity command of the take-up shaft calculated based on the main unit's linear velocity; u(k) is the tension adjustment signal, and in this mode, its unit is calibrated as speed compensation (rad / s); V set The host linear velocity set for the system, in meters per second (m / s); D C (k) is the stable winding diameter for the current control cycle, in meters (m).

[0119] In this way, when the material is overstretched (ε(k) is positive, and u(k) eventually becomes negative after PID adjustment), ω C,cmd ω(k) will decrease, and the winding shaft will slow down to reduce tension; as the material relaxes (ε(k) becomes negative, and eventually u(k) becomes positive), ω C,cmd (k) will increase, and the winding shaft will accelerate to tension the material.

[0120] The second implementation method (based on the correction of torque difference command):

[0121] In scenarios where the winding system employs torque control mode, the torque commands of the take-up and unwinding shafts can be dynamically superimposed and corrected using the tension adjustment signal u(k). The system first calculates a base torque command, which overcomes the system's frictional resistance and provides a basic winding tension. Subsequently, the tension adjustment signal u(k) is added as a torque compensation to the torque command of the take-up shaft 31, or subtracted from the braking torque command of the unwinding shaft 11.

[0122] Taking the correction of the take-up shaft torque as an example, the final torque command sent to the take-up shaft driver is calculated using the following formula:

[0123] T C,cmd (k)=T C,base (k)+u(k);

[0124] In the formula, T C,cmd (k) represents the torque command finally issued to the take-up shaft drive system in the current k-th control cycle, in Newton-meters (N·m); T C,base (k) is the system's basic torque command, which can be calculated from an open-loop taper tension curve; u(k) is the tension adjustment signal, and in this mode, its unit is calibrated as torque compensation (N·m).

[0125] In this way, when the material is overstretched, the compensation torque u(k) output by the PID controller will reduce the final winding torque T. C,cmd (k) decreases, thus reducing tension. Conversely, when the material is relaxed, the winding torque increases.

[0126] Through any of the above methods, the present invention can achieve dynamic correction of the driving command, thereby stabilizing the physical tensile state of the material at the target set point of zero tensile stress and completing the entire closed-loop control process.

[0127] The following describes the overall workflow provided by this invention in a series of complete application scenarios.

[0128] See attached document Figure 1 When the equipment is started, the operator sets the host linear velocity V on the human-machine interface of controller 5. set Basic process parameters, etc. During controller 5 initialization, it reads and stores parameters such as the preset thickness of material 4, the diameter of the unwinding and rewinding cores, and the conversion coefficients of each encoder. After the equipment starts running, the functional units within controller 5 begin to execute a closed-loop control method periodically.

[0129] In each control cycle, the acquisition unit 51 first synchronously acquires incremental data from the unwinding shaft 11, the metering roller 21, and the take-up shaft 31. Then, the roll diameter calculation unit 52 receives this data and, through a symmetrical differential algorithm model and exponential moving average filtering, calculates a precise and stable unwinding diameter D. A (k) and winding diameter D C (k). Subsequently, the diagnostic variable generation unit 53 uses this set of stable diameters to calculate the tensile characterization variable ε(k), which can quantify the tensile state of the material. This variable ε(k) is passed to the closed-loop adjustment signal generation unit 54, where the PID controller compares it with the zero target value to generate a tension adjustment signal u(k). Finally, the drive command correction unit 55 uses this signal u(k) as a compensation quantity, superimposed on the basic drive command to the take-up shaft 31 (or unwind shaft 11), and executes it through the drive system 6, thereby adjusting the shaft's operating state in real time to counteract tension fluctuations.

[0130] This process repeats itself in each control cycle, forming a continuous and adaptive closed-loop control that ensures that material 4 remains in the preset ideal tension state throughout the entire high-speed, wide-width winding process.

[0131] Real-time calculation of remaining material length:

[0132] By utilizing the stable roll diameter calculated in real time, this invention can also accurately calculate the remaining length or processed length of material 4 on the roll, providing data support for production management.

[0133] The first implementation method (based on the thickness method for calculating the remaining length):

[0134] This method uses geometric relationships to calculate the length of the remaining material on the unwound coil based on the current stable unwinding diameter.

[0135] First, calculate the cross-sectional area of ​​the material portion on the current roll. Based on this area and the preset thickness of a single layer of material, the total length of the material can be calculated. The calculation formula is as follows:

[0136]

[0137] In the formula, L rem (k) represents the remaining material length on the unwinding coil calculated in the current k-th control cycle, in meters (m); D A (k) represents the stable unwinding diameter for the current control cycle, in meters (m); D core,A Th is the core diameter of the unwinding spool 11, which is a preset known constant in meters (m); Th is the single-layer thickness of material 4, which is a preset known constant in meters (m).

[0138] The second implementation method (based on the calculation of processed length using the integration method):

[0139] This method calculates the total length of material processed since the start of operation by accumulating the linear length increments of the material measured by the metering roller 21 within each control cycle. This method is unaffected by the accuracy of the material thickness parameters. The calculation formula is as follows:

[0140] L proc (k)=L proc (k-1)+ΔL B (k);

[0141] In the formula, L proc (k) represents the total length of processed material up to the current k-th control cycle, in meters (m); L proc (k-1) represents the total length of material processed in the previous control cycle, with an initial value of 0; ΔL B (k) represents the linear length increment of the material in the current control cycle, in meters (m).

[0142] Through any of the above methods, the system can provide real-time data on material consumption and remaining usage to the user interface or the upper-level Manufacturing Execution System (MES).

[0143] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for calculating the roll diameter of high-speed and wide-width battery electrode equipment, characterized in that, The method includes the following steps: S1. In each control cycle, the unwind encoder, the metering encoder and the winding encoder are used to synchronously acquire the angle increment of the unwinding shaft, the linear length increment of the material and the angle increment of the winding shaft. S2. Based on the kinematic differential relationship between the linear length increment of the material and the angle increment of the unwinding and rewinding shafts, a symmetrical differential algorithm model is applied for real-time calculation to determine the stable unwinding diameter and stable rewinding diameter corresponding to the physical state of the winding equipment. S3. Based on the determined stable unwinding diameter and stable winding diameter, establish a quantitative evaluation model for online diagnosis of material physical integrity, and convert the dynamic mismatch between the theoretical absorption arc length calculated based on the winding side geometric parameters and the theoretical unwinding arc length calculated based on the unwinding side geometric parameters into a tensile characterization variable that can quantitatively characterize the physical tensile state of the material. S4. In a closed-loop control loop without a physical tension sensor, the tensile characterization variable is used as the only process feedback signal characterizing the actual material tension, and is compared in real time with the target set point of zero tension state to generate a tension adjustment signal for actively compensating for tension changes. S5. The tension adjustment signal is used to dynamically correct the drive command of the unwinding or rewinding shaft, thereby forming an adaptive tension closed-loop control in the winding equipment that is not dependent on physical measurement hardware and is driven by an algorithm.

2. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 1, characterized in that, Step S1, which involves simultaneously acquiring the angle increment of the unwinding shaft, the linear length increment of the material, and the angle increment of the rewinding shaft, includes: Based on the physical dimensions of the metering rollers installed on the metering encoders and the pulse resolution of each encoder, the conversion coefficients are pre-configured; The conversion coefficients are used to convert the raw pulse counts collected by the unwind encoder, metering encoder, and winding encoder during the control cycle into the angle increment of the unwind shaft, the linear length increment of the material, and the angle increment of the winding shaft, respectively.

3. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 1, characterized in that, In step S2, the steps for real-time calculation using a symmetric differential algorithm model, based on the kinematic differential relationship between the linear length increment of the material and the angular increments of the unwinding and rewinding shafts, include: Determine whether the absolute values ​​of the angle increments of the unwinding shaft and the winding shaft are greater than a preset threshold. If the determination result is yes, then use the linear length increment of the material, the angle increment of the unwinding shaft, and the angle increment of the winding shaft to calculate the instantaneous radius of the unwinding side and the instantaneous radius of the winding side using the following formula: In the formula, r A,inst r is the instantaneous radius on the unwinding side. C,inst ΔL is the instantaneous radius on the winding side; B Δθ represents the linear length increment of the material. A Δθ represents the angle increment of the unwinding spool. C This is the angle increment of the rewind spool.

4. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 3, characterized in that, In step S2, the symmetric differential algorithm model is applied for real-time solution, specifically including: The instantaneous radii of the unwinding side and the instantaneous radii of the winding side, determined by the calculation formulas of the instantaneous radii of the unwinding side and the instantaneous radii of the winding side, are used as inputs and smoothed by an exponential moving average filter to obtain stable unwinding diameter and stable winding diameter.

5. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 1, characterized in that, Step S3, based on the determined stable unwinding diameter and stable winding diameter, includes the following steps for establishing a quantitative assessment model for online diagnosis of material physical integrity: The quantitative evaluation model converts the dynamic mismatch into a stretching characterization variable using the following formula: In the formula, ε is the stretching characterization variable; For the theoretical absorption arc length; For the theoretical solution of the arc length; D A (k) is the stable unwinding diameter for the current control cycle; D C (k) is the stable winding diameter for the current control cycle; Δθ A Δθ represents the angle increment of the unwinding spool. C This is the angle increment of the rewind spool.

6. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 5, characterized in that, The quantitative evaluation model also includes the determination of the physical state of the stretching characterization variables: When the value of the stretching characterization variable ε is positive, it is determined that the material has been overstretched; When the value of the tensile characterization variable ε is negative, it is determined that the material has relaxed or slipped.

7. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 1, characterized in that, In step S4, the step of using the tensile characterization variable as the sole process feedback signal characterizing the actual material tension in a closed-loop control loop without a physical tension sensor, and comparing it in real time with the target setpoint of zero tension state, includes: In a PID controller, the stretching characterization variable is assigned to the process variable, and the target setpoint of the zero stretching state is assigned to the setpoint. The PID controller generates the tension adjustment signal based on the deviation between the process variable and the set value using a PID algorithm.

8. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 1, characterized in that, Step S5, which involves dynamically correcting the drive command of the unwinding or rewinding shaft using the tension adjustment signal, includes: The tension adjustment signal is used as a speed compensation value or torque compensation value to dynamically superimpose and correct the basic speed command or basic torque command of the unwinding shaft and the winding shaft respectively.

9. The method for calculating the roll diameter of a high-speed and wide-width battery electrode device according to claim 1, characterized in that, The method further includes: Based on the material cross-sectional area conservation relationship, and using the stable unwinding diameter and preset material thickness, the remaining length of the material is calculated. The total length of the processed material is calculated by summing the linear length increments of the material measured in each control cycle.

10. A roll diameter calculation system for high-speed and wide-width battery electrode equipment, applied to the method described in any one of claims 1-9, characterized in that, The system includes: The acquisition unit includes an unwind encoder, a metering encoder, and a take-up encoder. The acquisition unit is used to synchronously acquire the angle increment of the unwinding shaft, the linear length increment of the material, and the angle increment of the take-up shaft in each control cycle. The roll diameter calculation unit is used to perform real-time calculations based on the linear length increment of the material and the angle increments of the unwinding and rewinding shafts, using a symmetrical differential algorithm model, to determine a stable unwinding diameter and a stable rewinding diameter. The diagnostic variable generation unit is used to convert the dynamic mismatch between the theoretical absorption arc length calculated based on the geometric parameters of the winding side and the theoretical unwinding arc length calculated based on the geometric parameters of the unwinding side into a stretching characterization variable through a quantitative evaluation model based on the determined stable unwinding diameter and stable winding diameter. The closed-loop adjustment signal generation unit is used to compare the tension characterization variable as a process feedback signal with the target set point of zero tension state in a closed-loop control loop without a physical tension sensor to generate a tension adjustment signal. The drive command correction unit is used to dynamically correct the drive command of the unwinding or rewinding shaft using the tension adjustment signal, so as to form an algorithm-driven adaptive tension closed-loop control.

Images