Yarn tension feedforward control method, device, equipment and medium of embroidery machine

Abstract

This invention is primarily applicable to the field of embroidery machine technology. It discloses a method, device, equipment, and medium for feedforward control of yarn tension in an embroidery machine. The method involves acquiring data of the pattern to be embroidered within a look-ahead buffer; detecting the needle pattern switching point between the current and next needle steps; determining the theoretical thread consumption rate mutation value based on the needle step length and spindle speed; generating a compensation pulse command accordingly, the execution time parameter of which is synchronized with the spindle phase at the start of the next needle step; and controlling an electromagnetic direct-drive high-speed response actuator to perform active compensation within a preset window when the spindle reaches this phase, thus mitigating the transient impact of the thread consumption rate mutation on the yarn tension. This application achieves feedforward-feedback composite high-dynamic control of yarn tension during needle pattern switching transients, eliminating thread breakage and slippage, and ensuring stitch consistency in the transition area.

Description

Technical Field

[0001] This invention relates to the field of embroidery machine technology, specifically to a method, device, equipment, and medium for yarn tension feedforward control of an embroidery machine. Background Technology

[0002] During the high-speed operation of an embroidery machine, frequent changes in needlework can cause drastic changes in instantaneous thread consumption. This sudden change presents the yarn supply system with extreme dynamic tension challenges: at the moment of needlework switching, the thread demand may jump from zero to a peak value within milliseconds, or drop from high-speed supply to low-speed maintenance, causing drastic fluctuations in yarn tension.

[0003] Current tension control technologies for embroidery machines primarily rely on passive mechanical damping or closed-loop regulation based on encoder feedback. Passive damping solutions provide constant resistance through mechanical friction plates or spring mechanisms, but cannot respond to dynamic changes in thread loss rate, inevitably resulting in tension overshoot or undershoot when the thread loss rate changes abruptly. While encoder-based closed-loop solutions can monitor spool speed in real time, their control bandwidth is typically limited to tens of milliseconds due to mechanical transmission inertia, motor response delay, and signal processing lag, making them unsuitable for the high dynamic characteristics of needlework switching. More critically, existing solutions lack proactive awareness of disturbances such as sudden changes in thread loss rate, only compensating after tension deviations occur, resulting in control actions always lagging behind the disturbance and creating an inherent phase delay. Currently, there is an urgent need for an active tension control technology capable of proactively predicting sudden changes in thread loss rate and possessing high dynamic response capabilities to achieve lag-free and precise suppression of transient tension during needlework switching. Summary of the Invention

[0004] This invention provides a method, device, equipment, and medium for feedforward control of yarn tension in an embroidery machine, which can achieve high dynamic control of yarn tension through feedforward and feedback during the transient transition of needle techniques in the embroidery machine, effectively eliminating thread breakage and throwing phenomena and ensuring the consistency of stitches in the transition area.

[0005] This invention provides a yarn tension feedforward control method for an embroidery machine, the method comprising: Acquire the embroidery pattern data in the look-ahead buffer of the embroidery machine, wherein the embroidery pattern data includes at least the stitch length and the corresponding spindle speed; When a needle pattern switching point is detected between the current needle step and the next needle step of the embroidery machine, the sudden change value of the theoretical thread consumption rate between the current needle step and the next needle step is determined based on the needle step length and spindle speed of the current needle step and the next needle step. A compensation pulse instruction is generated based on the abrupt change value of the theoretical line consumption rate. The compensation pulse instruction includes at least an execution time parameter, which is set to be synchronized with the spindle phase angle at the start of the next needle step. When the spindle of the embroidery machine reaches the spindle phase angle at the start of the next stitch, the electromagnetic direct-drive high-speed response actuator is controlled by the compensation pulse command to perform active compensation action within a preset time window to counteract the transient impact on yarn tension caused by the sudden change in yarn consumption rate.

[0006] Optionally, the specific method for determining the theoretical line consumption rate is as follows: The theoretical line consumption rate is determined based on the ratio between the needle step length and the needle step time, wherein the needle step time is determined based on the spindle speed and the spindle rotation angle corresponding to the needle step.

[0007] Optionally, the specific method for generating the compensation pulse command based on the abrupt change value of the theoretical line consumption rate is as follows: Based on the abrupt change in the theoretical yarn consumption rate, the yarn physical property parameters, and the mechanical transmission characteristic parameters, the thrust amplitude and pulse duration required for this compensation are calculated, and a compensation pulse command containing the thrust amplitude and duration is generated.

[0008] Optionally, before the step of generating the compensation pulse command, the method further includes: Based on the abrupt change value of the theoretical yarn loss rate, yarn physical property parameters, and mechanical transmission characteristic parameters, a dynamic relationship model between the abrupt change in yarn loss rate and the peak value of tension impact is established. Based on the dynamic relationship model, the peak tension impact that will be generated at the needle technique mode switching point is determined. When the peak value of the tension impact exceeds the preset wire breakage threshold, the step of generating a compensation pulse command based on the abrupt change value of the theoretical wire consumption rate is executed.

[0009] Optionally, the calculation method for the peak tension impact includes: Obtain the elastic modulus parameter of the yarn and the length of the time window during which the yarn consumption rate changes abruptly; Based on the abrupt change in the theoretical line loss rate, the elastic modulus parameter, and the time window length, the predicted tension impact peak value is calculated according to a preset tension impact model, wherein the tension impact model indicates that the predicted tension impact peak value is proportional to the product of the abrupt change in the theoretical line loss rate, the elastic modulus parameter, and the time window length.

[0010] Optionally, the method for identifying the spindle phase angle of the embroidery machine at the start of the next stitch step includes: Obtain the spindle phase angle and detect the response delay time between receiving the command and generating mechanical action of the electromagnetic direct drive high-speed response actuator; Based on the current spindle speed and the response delay time, calculate the advance trigger angle, wherein the advance trigger angle is equal to the product of the current spindle speed and the response delay time; When the spindle phase angle is detected to be equal to the spindle phase angle at the start of the next stitch minus the advance trigger angle, it is determined that the spindle of the embroidery machine has reached the target phase angle, and the compensation pulse command is issued to control the electromagnetic direct drive high-speed response actuator to perform the active compensation action.

[0011] Optionally, the yarn tension feedforward control method of the embroidery machine further includes: The data of the pattern to be embroidered is analyzed to identify multiple different types of disturbance events, including needle pattern switching, color changing mechanism action and long-distance skipped stitches. The priority of each disturbance event is determined based on the expected impact of the disturbance event on the yarn tension. Calculate the time interval or the corresponding principal axis angle interval between the two disturbance events; When the time interval or the spindle angle interval is less than the preset fusion threshold, it is determined that there is a risk of compensation conflict, and a composite compensation pulse command is generated according to the priority of the target disturbance event and the expected impact amplitude. The composite compensation pulse command is executed within a single continuous time window to simultaneously deal with multiple disturbance events and allocate the tension compensation amplitude corresponding to each disturbance event according to the priority.

[0012] The present invention also provides a yarn tension feedforward control device for an embroidery machine, the device comprising: The acquisition module is used to acquire the embroidery pattern data in the look-ahead buffer of the embroidery machine. The embroidery pattern data includes at least the stitch length and the corresponding spindle speed. The calculation module is used to determine the abrupt change value of the theoretical thread consumption rate between the current needle step and the next needle step when a needle mode switching point is detected between the current needle step and the next needle step of the embroidery machine, based on the needle step length and spindle speed of the current needle step and the next needle step. The generation module is used to generate a compensation pulse instruction based on the abrupt change value of the theoretical line consumption rate. The compensation pulse instruction includes at least an execution time parameter, which is set to be synchronized with the spindle phase angle at the start of the next needle step. The control module is used to control the electromagnetic direct-drive high-speed response actuator to perform active compensation action within a preset time window when the main shaft of the embroidery machine runs to the main shaft phase angle at the start of the next stitch step, using the compensation pulse command, so as to counteract the transient impact on yarn tension caused by the sudden change in yarn consumption rate.

[0013] The present invention also provides an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the yarn tension feedforward control method for the embroidery machine as described in any of the preceding claims.

[0014] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the yarn tension feedforward control method for an embroidery machine as described in any of the preceding claims.

[0015] The present invention has at least the following beneficial effects: First, by utilizing a look-ahead buffer to acquire the data to be embroidered, the sudden change in the theoretical thread consumption rate is predicted at the needle pattern switching point, transforming the traditional reactive response into proactive intervention. Second, by synchronizing the execution time of the compensation pulse with the phase angle of the spindle in the next needle step, the electromagnetic direct-drive high-speed response actuator completes its pre-action before the mechanical system reaches a critical state, achieving precise alignment in the time dimension. Finally, the electromagnetic direct-drive high-speed response actuator performs active compensation within a preset window, using the high-frequency response characteristics of electromagnetic direct drive to quickly offset tension impacts. The feedforward path eliminates the main disturbances, and the feedback loop corrects residual deviations, forming a composite control structure. This effectively suppresses tension oscillations during needle pattern switching, preventing yarn breakage due to instantaneous overload or thread ejection due to under-tension, while ensuring uniform stitch density in the transition area. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0017] Figure 1 This is a flowchart illustrating the steps of a yarn tension feedforward control method for an embroidery machine. Figure 2 This is a schematic diagram of a yarn tension feedforward control method for an embroidery machine; Figure 3 This is a schematic diagram illustrating the effect of maintaining smooth and stable yarn tension during the actual switching process; Figure 4 This is a flowchart illustrating the steps involved in evaluating the peak tension impact in a yarn tension feedforward control method for an embroidery machine. Figure 5 This is a flowchart illustrating the steps involved in identifying the target spindle phase angle in a yarn tension feedforward control method for an embroidery machine. Figure 6 This is a flowchart illustrating the steps of handling various disturbance events in a yarn tension feedforward control method for an embroidery machine. Figure 7This is a schematic diagram of the structure of a yarn tension feedforward control device for an embroidery machine. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] In the field of embroidery machine technology, when an embroidery machine switches between different stitch patterns (such as switching from low-speed satin embroidery to high-speed line stitch), the instantaneous rate of yarn consumption changes drastically due to the simultaneous abrupt change in needle length and spindle speed. However, the researchers in this application found that traditional passive (spring) or low-dynamic electronic tensioners have mechanical lag and cannot keep up with this millisecond-level abrupt change in yarn consumption rate. This results in a sudden increase or decrease in tension at the moment of switching, causing the yarn to break or fall, creating a loop (thread ejection). Furthermore, the stitch tightness of several stitches before and after the switching point is inconsistent, affecting the smoothness of the embroidered surface.

[0020] To address the aforementioned technical problems, this technical solution proposes a method, device, equipment, and medium for feedforward control of yarn tension in an embroidery machine. This method enables high-dynamic control of yarn tension through a combination of feedforward and feedback during needle technique switching, effectively eliminating thread breakage and slippage while ensuring stitch consistency in transition areas. The following are various embodiments of this technical solution.

[0021] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating the steps of a yarn tension feedforward control method for an embroidery machine.

[0022] This embodiment provides a yarn tension feedforward control method for an embroidery machine, including: S101. Obtain the embroidery pattern data in the look-ahead buffer of the embroidery machine. The embroidery pattern data includes at least the stitch length and the corresponding spindle speed.

[0023] S102. When a needle pattern switching point is detected between the current needle step and the next needle step of the embroidery machine, the sudden change value of the theoretical thread consumption rate between the current needle step and the next needle step is determined based on the needle step length and spindle speed of the current needle step and the next needle step.

[0024] S103. Generate a compensation pulse instruction based on the sudden change value of the theoretical line consumption rate. The compensation pulse instruction includes at least an execution time parameter, which is set to be synchronized with the spindle phase angle at the start of the next needle step.

[0025] S104. When the spindle of the embroidery machine reaches the spindle phase angle at the start of the next stitch, the electromagnetic direct drive high-speed response actuator is controlled by the compensation pulse command to perform active compensation action within the preset time window to counteract the transient impact on yarn tension caused by the sudden change in yarn consumption rate.

[0026] Please refer to Figure 2 , Figure 2 This is a schematic diagram of a yarn tension feedforward control method for an embroidery machine.

[0027] like Figure 2 As shown, the pattern data in the look-ahead buffer is first analyzed, and the theoretical changes in thread length and time before and after the mode switching point are calculated. In this way, a transient thread rate mutation model is established to predict the upcoming tension impact peak.

[0028] In some embodiments, the electromagnetic direct-drive high-speed response actuator abandons the traditional stepper motor and adopts a voice coil motor (VCM) with a kHz-level response bandwidth to directly drive the yarn clamping plates, enabling it to instantly release or tighten the yarn.

[0029] Based on the transient yarn loss rate mutation model, a "reverse compensation force / displacement pulse" with the opposite direction and precisely matched amplitude to the interference impact is generated. This pulse is strictly anchored to the main shaft phase and drives the VCM to actively move within the microsecond time window when the mode switch occurs, perfectly offsetting the transient impact at the mechanical end and keeping the actual yarn tension smooth and stable during the switching process.

[0030] Please refer to Figure 3 , Figure 3 This is a schematic diagram illustrating the effect of maintaining smooth and stable yarn tension during the actual switching process.

[0031] Understandably, in this embodiment, firstly, the data to be embroidered is acquired using a look-ahead buffer, and the sudden change in the theoretical thread consumption rate is predicted at the needle pattern switching point, transforming the traditional reactive response into proactive intervention. Secondly, by synchronizing the execution time of the compensation pulse with the phase angle of the spindle in the next stitch step, the voice coil motor is ensured to complete its pre-action before the mechanical system reaches a critical state, achieving precise alignment in the time dimension. Finally, the voice coil motor performs active compensation within a preset window, using the high-frequency response characteristics of electromagnetic direct drive to quickly offset tension impacts. The feedforward path eliminates the main disturbances, and the feedback loop corrects residual deviations, forming a composite control structure. This effectively suppresses tension oscillations during needle pattern switching, preventing yarn breakage due to instantaneous overload or thread ejection due to insufficient tension, while ensuring uniform stitch density in the transition area.

[0032] In some embodiments, the specific method for determining the theoretical line loss rate is as follows: The theoretical line consumption rate is determined based on the ratio between the needle step length and the needle step time, wherein the needle step time is determined based on the spindle speed and the spindle rotation angle corresponding to the needle step.

[0033] In some embodiments, the specific method for generating compensation pulse commands based on the abrupt change in the theoretical line consumption rate is as follows: Based on the abrupt change in the theoretical yarn consumption rate, yarn physical property parameters, and mechanical transmission characteristic parameters, the thrust amplitude and pulse duration required for this compensation are calculated, forming a compensation pulse command that includes the thrust amplitude and duration.

[0034] Please refer to Figure 4 , Figure 4 This is a flowchart illustrating the steps involved in evaluating the peak tension impact in a yarn tension feedforward control method for an embroidery machine.

[0035] In some embodiments, prior to the step of generating compensation pulse instructions, a yarn tension feedforward control method for an embroidery machine further includes: S201. Based on the abrupt change value of the theoretical yarn loss rate, yarn physical property parameters, and mechanical transmission characteristic parameters, a dynamic relationship model between the abrupt change in yarn loss rate and the peak value of tension impact is established.

[0036] S202. Based on the dynamic relationship model, determine the peak tension impact that will be generated at the needle pattern switching point.

[0037] S203. When the peak value of the tension impact exceeds the preset wire breakage threshold, execute the step of generating a compensation pulse command based on the sudden change value of the theoretical wire consumption rate.

[0038] Understandably, this embodiment establishes a dynamic relationship model between sudden changes in yarn loss rate and peak tension impact to achieve quantitative prediction of tension impact at needle technique switching points. Only when the predicted impact exceeds the yarn breakage threshold is a compensation pulse command generated, forming an intelligent control closed loop from prediction to decision-making to execution. This embodiment adds a model-driven pre-judgment mechanism, making compensation actions more targeted and avoiding ineffective intervention; simultaneously, parameterized modeling of yarn physical properties and mechanical transmission characteristics improves compensation accuracy. Ultimately, it achieves adaptive high-dynamic control of yarn tension during needle technique switching transients, reducing system energy consumption while eliminating yarn breakage and slippage, and ensuring stitch consistency in the transition area.

[0039] In some embodiments, the peak tension impact is calculated as follows: Obtain the elastic modulus parameter of the yarn and the time window length during which the yarn consumption rate changes abruptly; based on the abrupt change value of the theoretical yarn consumption rate, the elastic modulus parameter, and the time window length, calculate and predict the peak tension impact according to the preset tension impact model, wherein the tension impact model is expressed as the predicted peak tension impact being proportional to the product of the abrupt change value of the theoretical yarn consumption rate, the elastic modulus parameter, and the time window length.

[0040] Please refer to Figure 5 , Figure 5 This is a flowchart illustrating the steps involved in identifying the target spindle phase angle in a yarn tension feedforward control method for an embroidery machine.

[0041] In some embodiments, the method of identifying the spindle phase angle of the embroidery machine at the start of the next stitch step includes: S301. Obtain the spindle phase angle and detect the response delay time between receiving the command and generating mechanical action of the electromagnetic direct drive high-speed response actuator.

[0042] S302. Calculate the advance trigger angle based on the current spindle speed and response delay time, where the advance trigger angle is equal to the product of the current spindle speed and the response delay time.

[0043] S303. When the spindle phase angle is detected to be equal to the spindle phase angle at the start of the next stitch minus the advance trigger angle, it is determined that the spindle of the embroidery machine has reached the target phase angle, and a compensation pulse command is issued to control the electromagnetic direct drive high-speed response actuator to perform active compensation action.

[0044] Understandably, this embodiment establishes a compensation mechanism for the advance trigger angle by real-time detection of the response delay of the electromagnetic direct-drive high-speed response actuator, achieving precise alignment between command transmission and mechanical action. Based on the dynamic product calculation of the current spindle speed and the delay time, the command is pre-issued before the spindle reaches the target phase, eliminating the compensation timing deviation caused by motor response lag. This embodiment adds an adaptive phase correction stage, enabling zero-error synchronization between the active compensation action and the needle switching critical point, significantly improving the phase accuracy of the feedforward control. Ultimately, it achieves highly dynamic and precise control of yarn tension during needle switching transients, effectively suppressing residual tension fluctuations caused by timing misalignment, further eliminating the risk of yarn breakage and slippage, and improving stitch consistency in the transition area.

[0045] Please refer to Figure 6 , Figure 6 This is a flowchart illustrating the steps of handling various disturbance events in a yarn tension feedforward control method for an embroidery machine.

[0046] In some embodiments, a yarn tension feedforward control method for an embroidery machine further includes: S401. Analyze the embroidery pattern data to identify multiple different types of disturbance events, including needle pattern switching, color changing mechanism action, and long-distance skipped stitches.

[0047] S402. Determine the priority of each disturbance event based on the expected impact of the disturbance event on the yarn tension.

[0048] S403. Calculate the time interval or the corresponding principal axis angle interval between two disturbance events.

[0049] S404. When the time interval or spindle angle interval is less than the preset fusion threshold, it is determined that there is a risk of compensation conflict. Based on the priority of the target disturbance event and the expected impact amplitude, a composite compensation pulse command is generated. The composite compensation pulse command is executed within a single continuous time window to deal with multiple disturbance events simultaneously and to allocate the tension compensation amplitude corresponding to each disturbance event according to the priority.

[0050] Understandably, this embodiment establishes a composite compensation mechanism through intelligent identification and priority ranking of multiple types of disturbance events (such as needlework switching, color changing, and long-distance skipped stitches). When the interval between adjacent disturbance events is less than the fusion threshold, a composite compensation pulse with a single continuous time window is generated, and the tension compensation amplitude corresponding to each event is allocated according to priority to avoid execution disorder caused by multiple instruction conflicts. This embodiment adds multi-disturbance collaborative processing capability, breaking through the limitations of single-event compensation and realizing spatiotemporal optimization of tension control in complex embroidery scenarios. Ultimately, it achieves high dynamic adaptive control of multi-disturbance coupled transients, effectively eliminating thread breakage and slippage under complex working conditions such as dense needlework switching and frequent color changing, ensuring the consistency of stitches across the entire surface.

[0051] This technical solution also provides a specific embodiment where the embroidery machine control system adopts a two-tier architecture. The upper prediction layer is run by the main controller STM32F407, equipped with 1MB Flash and 192KB SRAM, responsible for pattern data parsing and compensation parameter pre-calculation. The lower execution layer uses an FPGA chip with an operating frequency of 28MHz, achieving microsecond-level interrupt response. The spindle encoder has a resolution of 3600 lines / revolution, and together with the hardware capture unit, achieves a phase detection accuracy of ±0.5 microseconds. The voice coil motor is a linear motor with a peak thrust of 5N and a bandwidth greater than 1kHz, directly connected to the FPGA through an H-bridge driver chip.

[0052] First, the data to be embroidered is read from the embroidery pattern file, and a look-ahead buffer containing the next 20 stitches is established. For each stitch, the following information is parsed: stitch length L, spindle speed N, and stitch type identifier. Taking a typical scenario of switching from satin embroidery to line stitch as an example, the current stitch parameters are: stitch length 0.5mm, spindle speed 500rpm; the next stitch parameters abruptly change to: stitch length 2.0mm, spindle speed 1200rpm.

[0053] Next, the parameters of two adjacent needles are compared to calculate the abrupt change in the thread consumption rate. The formula for calculating the thread consumption rate R is R = L × N × k, where k is the unit conversion factor. The current thread consumption rate R1 = 1600 mm / min, and the next needle's thread consumption rate R2 = 6000 mm / min, resulting in a sudden change ΔR = 4400 mm / min, equivalent to 73.3 mm / s. This sudden change exceeds a preset threshold, indicating a needle pattern switching point.

[0054] Next, the expected tensile impact is calculated based on the dynamic relationship model. The model formula is ΔTension = 0.5×ΔR×E, where E is the combined coefficient of yarn elastic modulus and transmission damping, which is taken as 0.1 in this embodiment. Substituting, we get ΔTension≈0.5×73.3×0.1=3.67N. Considering the mechanical transmission amplification effect, the actual peak impact is estimated to be 22N, exceeding the breakage threshold of 15N, triggering the compensation command generation process.

[0055] Next, the voice coil motor compensation pulse parameters were determined. A Gaussian waveform pulse was used, with a peak thrust set to 3.5N (70% of the motor's maximum thrust), a pulse width σ = 1ms, and a pulse energy of approximately 8.75mJ. The execution time parameters were calculated: at a spindle speed of 1200rpm, the voice coil motor response delay was approximately 0.5ms, corresponding to an advance trigger angle θ_advance = 1200 ÷ 60 × 360 × 0.001 × 6 = 3.6 degrees. The compensation pulse was bound to the next pin's starting spindle phase angle of 123.5 degrees, and the actual trigger angle was set to 119.9 degrees.

[0056] Furthermore, the FPGA operates a position comparison interrupt at a frequency of 28MHz. When the spindle encoder feedback angle reaches 119.9 degrees, the hardware capture unit triggers an interrupt with an accuracy of ±0.5 microseconds, and the FPGA immediately sends a PWM command to the voice coil motor driver. The voice coil motor builds up thrust within 0.5ms, reaching its peak when the spindle reaches the 123.5-degree switching point, actively releasing the yarn to counteract the pulling impact caused by the surge in yarn consumption.

[0057] Additionally, when dense disturbances exist in the pattern data, a fusion strategy is executed. For example, if a color-changing mechanism is detected within 30ms after a needle pattern switch, the time interval is determined to be less than the 50ms fusion threshold. The priorities of the two are compared: needle pattern switching has a priority of level one, and color-changing action has a priority of level two. A composite compensation pulse is generated: within a single 2.5ms continuous window, a 3.5N thrust pulse is executed in the first 1.5ms to handle the mode switch, and a 1.2N pull pulse is executed in the last 1.0ms to pre-compensate for color-changing relaxation. The amplitudes of the two pulses are weighted according to their priorities.

[0058] Finally, the system of this embodiment was used to conduct a high-speed embroidery test on polyester filament with a linear density of 75D and a preset tension of 200g. A comparison was made between traditional PID feedback control and the feedforward composite control of this scheme: Tension fluctuation was reduced from ±12N to ±2N, and transient impact cancellation rate reached 92%. Thread breakage rate decreased from 15%-20% to below 1%. The number of stitches in the transition area between stitch patterns was shortened from 15-20 stitches to less than 3 stitches, and the difference in stitch tightness was less than 5%. In complex patterns involving frequent switching between high-speed 1200rpm sewing and low-speed 500rpm satin embroidery, the surface smoothness of the embroidery met export standards, with no visible transition marks.

[0059] Please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of a yarn tension feedforward control device for an embroidery machine.

[0060] This embodiment provides a yarn tension feedforward control device for an embroidery machine, comprising: The acquisition module 501 is used to acquire the embroidery pattern data in the look-ahead buffer of the embroidery machine. The embroidery pattern data includes at least the stitch length and the corresponding spindle speed.

[0061] The calculation module 502 is used to determine the sudden change value of the theoretical thread consumption rate between the current needle step and the next needle step when a needle mode switching point is detected between the current needle step and the next needle step of the embroidery machine, based on the needle step length and spindle speed of the current needle step and the next needle step.

[0062] The generation module 503 is used to generate a compensation pulse instruction based on the abrupt change value of the theoretical line consumption rate. The compensation pulse instruction includes at least an execution time parameter, which is set to be synchronized with the spindle phase angle at the start of the next needle step.

[0063] The control module 504 is used to control the electromagnetic direct-drive high-speed response actuator to perform active compensation action within a preset time window when the main shaft of the embroidery machine reaches the main shaft phase angle at the start of the next stitch step, so as to counteract the transient impact on yarn tension caused by the sudden change in yarn consumption rate.

[0064] It will be understood by those skilled in the art that all or some of the steps and apparatuses in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. As is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0065] It is understood that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0066] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the yarn tension feedforward control method of any of the above embroidery machines.

[0067] It is understood that the content of the above method embodiments is applicable to the embodiments of this electronic device. The specific functions implemented by the embodiments of this electronic device are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0068] This application also provides a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to implement the yarn tension feedforward control method for an embroidery machine as described in any of the above specific embodiments.

[0069] This application also discloses a computer program product, including a computer program or computer instructions, which are stored in a computer-readable storage medium. The processor of the computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform the yarn tension feedforward control method for an embroidery machine as described in any of the preceding embodiments.

[0070] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0071] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices. It should be understood that in this application, “at least one” means one or more, and “more than one” means two or more.

[0072] In the several embodiments provided in this application, it should be understood that the disclosed apparatus, devices, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0073] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0074] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0075] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0076] Although the description of this application has been quite detailed and particularly focused on several of the described embodiments, it is not intended to limit itself to any of these details or embodiments or any particular embodiment. Rather, it should be considered as effectively covering the intended scope of this application by referring to the appended claims and taking into account the prior art, which provides for a broad possible interpretation of these claims. Furthermore, the foregoing description of this application with respect to embodiments foreseeable by the inventors is intended to provide a useful description, and non-substantial modifications to this application that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A method for feedforward control of yarn tension in an embroidery machine, characterized in that, The method includes: Acquire the embroidery pattern data in the look-ahead buffer of the embroidery machine, wherein the embroidery pattern data includes at least the stitch length and the corresponding spindle speed; When a needle pattern switching point is detected between the current needle step and the next needle step of the embroidery machine, the sudden change value of the theoretical thread consumption rate between the current needle step and the next needle step is determined based on the needle step length and spindle speed of the current needle step and the next needle step. A compensation pulse instruction is generated based on the abrupt change value of the theoretical line consumption rate. The compensation pulse instruction includes at least an execution time parameter, which is set to be synchronized with the spindle phase angle at the start of the next needle step. When the spindle of the embroidery machine reaches the spindle phase angle at the start of the next stitch, the electromagnetic direct-drive high-speed response actuator is controlled by the compensation pulse command to perform active compensation action within a preset time window to counteract the transient impact on yarn tension caused by the sudden change in yarn consumption rate.

2. The method according to claim 1, characterized in that, The specific method for determining the theoretical line loss rate is as follows: The theoretical line consumption rate is determined based on the ratio between the needle step length and the needle step time, wherein the needle step time is determined based on the spindle speed and the spindle rotation angle corresponding to the needle step.

3. The method according to claim 1, characterized in that, The specific method for generating compensation pulse commands based on the abrupt change in the theoretical line consumption rate is as follows: Based on the abrupt change in the theoretical yarn consumption rate, the yarn physical property parameters, and the mechanical transmission characteristic parameters, the thrust amplitude and pulse duration required for this compensation are calculated, and a compensation pulse command containing the thrust amplitude and duration is generated.

4. The method according to claim 1, characterized in that, Prior to the step of generating the compensation pulse command, the method further includes: Based on the abrupt change value of the theoretical yarn loss rate, yarn physical property parameters, and mechanical transmission characteristic parameters, a dynamic relationship model between the abrupt change in yarn loss rate and the peak value of tension impact is established. Based on the dynamic relationship model, the peak tension impact that will be generated at the needle technique mode switching point is determined. When the peak value of the tension impact exceeds the preset wire breakage threshold, the step of generating a compensation pulse command based on the abrupt change value of the theoretical wire consumption rate is executed.

5. The method according to claim 4, characterized in that, The calculation method for the peak tension impact includes: Obtain the elastic modulus parameter of the yarn and the length of the time window during which the yarn consumption rate changes abruptly; Based on the abrupt change in the theoretical line loss rate, the elastic modulus parameter, and the time window length, the predicted tension impact peak value is calculated according to a preset tension impact model, wherein the tension impact model indicates that the predicted tension impact peak value is proportional to the product of the abrupt change in the theoretical line loss rate, the elastic modulus parameter, and the time window length.

6. The method according to claim 1, characterized in that, The methods for identifying the spindle phase angle of the embroidery machine at the start of the next stitch step include: Obtain the spindle phase angle and detect the response delay time between receiving the command and generating mechanical action of the electromagnetic direct drive high-speed response actuator; Based on the current spindle speed and the response delay time, calculate the advance trigger angle, wherein the advance trigger angle is equal to the product of the current spindle speed and the response delay time; When the spindle phase angle is detected to be equal to the spindle phase angle at the start of the next stitch minus the advance trigger angle, it is determined that the spindle of the embroidery machine has reached the target phase angle, and the compensation pulse command is issued to control the electromagnetic direct drive high-speed response actuator to perform the active compensation action.

7. The method according to claim 1, characterized in that, The method further includes: The data of the pattern to be embroidered is analyzed to identify multiple different types of disturbance events, including needle pattern switching, color changing mechanism action and long-distance skipped stitches. The priority of each disturbance event is determined based on the expected impact of the disturbance event on the yarn tension. Calculate the time interval or the corresponding principal axis angle interval between the two disturbance events; When the time interval or the spindle angle interval is less than the preset fusion threshold, it is determined that there is a risk of compensation conflict, and a composite compensation pulse command is generated according to the priority of the target disturbance event and the expected impact amplitude. The composite compensation pulse command is executed within a single continuous time window to simultaneously deal with multiple disturbance events and allocate the tension compensation amplitude corresponding to each disturbance event according to the priority.

8. A yarn tension feedforward control device for an embroidery machine, characterized in that, The device includes: The acquisition module is used to acquire the embroidery pattern data in the look-ahead buffer of the embroidery machine. The embroidery pattern data includes at least the stitch length and the corresponding spindle speed. The calculation module is used to determine the abrupt change value of the theoretical thread consumption rate between the current needle step and the next needle step when a needle mode switching point is detected between the current needle step and the next needle step of the embroidery machine, based on the needle step length and spindle speed of the current needle step and the next needle step. The generation module is used to generate a compensation pulse instruction based on the abrupt change value of the theoretical line consumption rate. The compensation pulse instruction includes at least an execution time parameter, which is set to be synchronized with the spindle phase angle at the start of the next needle step. The control module is used to control the electromagnetic direct-drive high-speed response actuator to perform active compensation action within a preset time window when the main shaft of the embroidery machine runs to the main shaft phase angle at the start of the next stitch step, using the compensation pulse command, so as to counteract the transient impact on yarn tension caused by the sudden change in yarn consumption rate.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the yarn tension feedforward control method for the embroidery machine according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the yarn tension feedforward control method for the embroidery machine according to any one of claims 1 to 7.

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