Multi-station automatic embroidery device on a mattress production line and method thereof

Abstract

The present application relates to the field of textile machinery and automation equipment, in particular to a multi-station automatic embroidery device on a mattress production line, comprising a main frame, a front and rear pressure conveying belt column, a pressure holding unit, an embroidery execution head and a master-slave control system; the device uses front and rear conveying servo motors to drive synchronous belts to segmentally clamp and pull the fabric on both sides of the needle drop area; the core is to combine the pressure holding unit containing a damping cylinder and a pre-tightening spring to make the presser foot plate apply passive follow-up pressure holding force adapting to the fabric thickness fluctuation; the present application uses segmented pulling and continuous supporting to effectively suppress local rebound and keep the fabric in stable stress constraint, thereby improving the stability of the reference inheritance and the quality of the pattern matching, aiming at the problem that the position reference cannot be stably inherited due to the easy slippage of the fabric.

Description

Technical Field

[0001] This invention relates to the field of textile machinery and automation equipment, specifically to a multi-station automatic embroidery device and method for a mattress production line. Background Technology

[0002] In the current production process of mattress composite fabrics, multi-station automatic embroidery equipment typically relies on the uniform sliding of ordinary conveyor rollers to complete the continuous cross-station transfer of large-sized fabrics. To maintain multi-station collaborative processing, existing solutions generally adopt a rigid unified mechanical cycle architecture, that is, a single main shaft synchronously drives all conveyor components forward, supplemented by pure optical vision devices for seam anomaly detection. Although this solution has a certain processing capability in conventional processing scenarios, the probability of micro-slippage due to gravity, local thickness fluctuations, and uneven friction of large-sized soft fabrics is relatively high, resulting in the inability to stably inherit the position reference of the previous station in the next station. At the same time, this rigid synchronous control mechanism cannot cope with dynamic interference. Once a local anomaly occurs in a single embroidery execution head, the entire line needs to be shut down for manual handling. In addition, high concentrations of fiber dust can easily contaminate optical lenses, causing them to malfunction, resulting in deterioration of condition monitoring accuracy and frequent unplanned shutdowns, making it difficult to support high-quality pattern matching and automatic task rearrangement and seam filling under continuous production conditions.

[0003] Therefore, how to improve the baseline stability inheritance capability of soft fabric cross-workstation transmission and the continuous operation capability of the entire line under local abnormal conditions has become an urgent technical problem to be solved. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a multi-station automatic embroidery device and method for a mattress production line. Specifically, the technical solution of the present invention is as follows: On one hand, the present invention provides a multi-station automatic embroidery device for a mattress production line, comprising: The main frame has a station beam parallel to the conveying direction, on which a fabric support plate is fixed. A transition gap is formed between adjacent fabric support plates, and a front pressure conveyor belt and a rear pressure conveyor belt are set on both sides of the transition gap. The front press-feed belt column includes a front synchronous belt driven by a front conveyor servo motor; the rear press-feed belt column includes a rear synchronous belt driven by a rear conveyor servo motor; a needle drop area is left between the front and rear synchronous belts; A pressure beam is installed above the workstation beam, and pressure units are installed at intervals below it. The pressure unit includes a pressure foot plate, a guide rod, a damping cylinder and a pre-tightening spring. The pressure foot plate is slidably connected to the pressure beam via the guide rod. The pre-tightening spring is between the pressure beam and the pressure foot plate. The cylinder body of the damping cylinder is fixed to the pressure beam, and the piston rod is hinged to the pressure foot plate. An embroidery execution head containing a needle bar is fixed in the middle of the workstation beam, and the movement area of ​​the needle bar is above the needle drop area; the device includes a workstation controller and a main controller with communication connection, the workstation controller being electrically connected to the front conveyor servo motor, the rear conveyor servo motor and the embroidery execution head respectively; the main controller stores a workstation cycle table, a handover sequence table and a buffer occupancy table, and issues control commands accordingly.

[0005] As a further embodiment of the present invention, the outer surfaces of both the front and rear synchronous belts are fixed with micro-tooth elastic embossed layers; wherein, the micro-tooth elastic embossed layers are made of polyurethane, and the surface of the micro-tooth elastic embossed layers is processed with continuous shallow teeth along the conveying direction.

[0006] As a further embodiment of the present invention, the embroidery execution head further includes a thread tensioning lever, a lever detection plate, and a proximity switch; wherein, the first end of the thread tensioning lever is supported on the head base of the embroidery execution head, the lever detection plate is fixedly connected to the thread tensioning lever, the proximity switch is fixed to the head base and faces the lever detection plate, and the proximity switch is electrically connected to the workstation controller; the workstation controller receives the detection signal from the proximity switch, converts the detection signal into a sewing confidence level, and transmits the sewing confidence level to the main controller.

[0007] As a further embodiment of the present invention, a transition buffer platform is provided between the crossbeams of adjacent workstations; wherein, the transition buffer platform includes a fixed platform and a floating pressure strip, the end of the floating pressure strip is slidably engaged with the fixed platform through a short guide rod, and a buffer spring is sleeved on the short guide rod.

[0008] On the other hand, the present invention further proposes a control method for a multi-station automatic embroidery device on a mattress production line, comprising the following steps: S1. Execute the workstation baseline establishment step, obtain the fabric tail amount of each workstation, and write the fabric tail amount into the workstation cycle table corresponding to the workstation. S2. Execute the normal embroidery steps. The main controller sends the operation sequence to the work station controller according to the work station cycle table, controls the front pressure feeder, the rear pressure feeder and the embroidery execution head to work together, and obtains the sewing reliability of each work station. S3. Obtain a preset level threshold and determine the relationship between the seam formation reliability and the preset level threshold. S4. If the seam completion reliability is lower than the preset level threshold, the corresponding workstation is determined to be an abnormal workstation. The workstation transfer step is performed according to the buffer occupancy table and the transfer order table, and the adjacent workstations share the seam repair task of the abnormal workstation. If the seam completion reliability is greater than or equal to the preset level threshold, the normal embroidery step is maintained.

[0009] As a further aspect of the present invention, the step of obtaining the fabric trailing amount at each workstation in S1 includes: controlling the front conveying servo motor and the rear conveying servo motor to advance the fabric at a low speed, while controlling the embroidery execution head to perform empty needle rhythm movement; determining the fabric trailing amount based on the displacement stabilization time of the embroidery execution head and the displacement completion time of the front conveying servo motor and the rear conveying servo motor; and writing the difference in the fabric trailing amount between adjacent workstations into the buffer occupancy table.

[0010] As a further aspect of the present invention, the step of controlling the coordinated operation of the front pressure feeder, the rear pressure feeder, and the embroidery execution head in S2 includes: the front pressure feeder holding the fabric in place, the rear pressure feeder being unloaded, and the front section of the fabric being pulled into the needle drop area; when the fabric reaches the stitch start position, the front pressure feeder and the rear pressure feeder simultaneously enter a holding state, and the embroidery execution head completes the stitch cluster; after the stitch cluster is completed, the rear pressure feeder takes over the traction first, and the front pressure feeder releases after a delay, forming an overlapping force period.

[0011] As a further embodiment of the present invention, the step of performing workstation transfer according to the buffer occupancy table and the transfer sequence table in S4 includes: calculating the current fabric length margin that the transition buffer platform before and after the abnormal workstation can accommodate according to the buffer occupancy table, and comparing the length margin with a preset safety transport threshold; wherein, the safety transport threshold is a length critical value determined based on the physical capacity limit length of the transition buffer platform and the reserved safety buffer length. If the length margin is greater than or equal to the safe conveying threshold, it is determined that there is a length margin. Then, the embroidery execution head of the abnormal workstation is controlled to lift the needle and stop rotating, the front pressure conveyor belt of the abnormal workstation is controlled to enter the release state, and the rear pressure conveyor belt of the abnormal workstation is controlled to enter the low traction state. According to the transfer sequence table, the stitch area originally planned to be handled by the abnormal workstation is divided into the first half to be filled by the preceding workstation, the second half to be filled by the following workstation, or the stitching to be filled by the adjacent workstation on one side; if there is no length margin, the entire line is stopped and an alarm signal is issued.

[0012] As a further aspect of the present invention, the step of patching the first half of the area by the preceding workstation, patching the second half of the area by the following workstation, or patching the seam by a single adjacent workstation includes: reading the end point position of the most recently completed stitch at the abnormal workstation, the release time of the preceding workstation, and the waiting time of the preceding stitch cluster at the following workstation. Based on the sequential relationship between the stitch end position, the release time, and the waiting time, determine whether the current fabric is dominated by the front traction or the rear traction in the middle of the abnormal workstation. If the preceding stage is the dominant force, the seam repair task will be preferentially assigned to the subsequent workstation. If the subsequent stage is the dominant force, the seam repair task will be preferentially assigned to the preceding workstation.

[0013] As a further aspect of the present invention, before step S1, a pre-adjustment step is included: controlling the holding beam to descend to a reference height, controlling the damping cylinder to maintain a uniform low pressure; advancing the fabric of the test length at a low speed; and adjusting the airflow throttling degree of the damping cylinder corresponding to the workstation according to the fabric trailing amount formed at each workstation in the test length.

[0014] The present invention has the following beneficial effects: 1. This invention addresses the problem of unstable positional reference inheritance caused by fabric slippage. By setting up front and rear pressure conveyor belts on both sides of the needle drop area, and driving the front and rear synchronous belts with front and rear conveyor servo motors respectively, the fabric is segmented and clamped. With the guide rod, pre-tension spring and damping cylinder of the pressing unit, the presser foot plate applies a passive follow-up pressing force to adapt to thickness fluctuations and suppress local rebound. Combined with the continuous support of the fabric support plate, the fabric maintains stable force constraint between each workstation, effectively improving the stability of reference inheritance and pattern matching quality.

[0015] 2. This invention addresses the problem of entire production line shutdown caused by localized anomalies at a single workstation. It issues control commands by calling the workstation cycle time table, buffer occupancy table, and transfer sequence table through the main controller. During normal embroidery steps, the stitch completion reliability is obtained; when it falls below a preset level, the workstation is determined to be an abnormal workstation. In this case, the system does not need to shut down the entire line; instead, it executes a workstation transfer step based on the table data, allowing adjacent workstations to share the stitching task of the abnormal workstation. This control method enables automatic task rearrangement in soft fabric processing under localized abnormal conditions, optimizing the continuous operation capability of the entire production line. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the overall external structure of the device; Figure 2 This is a bottom view of the main frame structure; Figure 3 This is a schematic diagram of the holding unit; Figure 4 This is a structural diagram of the embroidery execution head and the transition buffer platform; Figure 5 This is a flowchart of the method according to an embodiment of the present invention.

[0017] In the diagram: 1. Main frame; 2. Workstation crossbeam; 3. Fabric support platform; 4. Transition gap; 5. Front pressure conveyor belt; 6. Rear pressure conveyor belt; 7. Front conveyor servo motor; 8. Front synchronous belt; 9. Rear conveyor servo motor; 10. Rear synchronous belt; 11. Needle drop area; 12. Pressing crossbeam; 13. Pressing unit; 14. Presser foot plate; 15. Guide rod; 16. Damping cylinder; 17. Pre-tension spring; 18. Embroidery actuator head; 19. Needle bar; 20. Thread tensioning swing arm; 21. Swing arm detection plate; 22. Proximity switch; 23. Head base; 24. Transition buffer platform; 25. Fixed platform; 26. Floating pressure bar; 27. Short guide rod; 28. Buffer spring. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0019] Example 1:

[0020] like Figure 1 and Figure 2 As shown, a multi-station automatic embroidery device for a mattress production line includes: Main frame 1, with station crossbeam 2 parallel to the conveying direction, on which fabric support plate 3 is fixed, and a transition gap 4 is formed between adjacent fabric support plates 3. A front pressure conveyor belt 5 and a rear pressure conveyor belt 6 are respectively set on both sides of the transition gap 4. The front press feeder belt 5 includes a front synchronous belt 8 driven by a front conveyor servo motor 7; the rear press feeder belt 6 includes a rear synchronous belt 10 driven by a rear conveyor servo motor 9; and a needle drop area 11 is left between the front synchronous belt 8 and the rear synchronous belt 10. Please see Figure 3 Above the workstation beam 2, a holding beam 12 is provided, and holding units 13 are provided at intervals below. The holding unit 13 includes a pressure foot plate 14, a guide rod 15, a damping cylinder 16, and a preload spring 17. The pressure foot plate 14 is slidably connected to the holding beam 12 via the guide rod 15. The preload spring 17 is located between the holding beam 12 and the pressure foot plate 14. The cylinder body of the damping cylinder 16 is fixed to the holding beam 12, and the piston rod is hinged to the pressure foot plate 14. Please see Figure 1 and Figure 4The embroidery execution head 18, which includes a needle bar 19, is fixed in the middle of the crossbeam 2 of the workstation. The movement area of ​​the needle bar 19 is above the needle drop area 11. The device includes a workstation controller and a main controller with communication connection. The workstation controller is electrically connected to the front conveyor servo motor 7, the rear conveyor servo motor 9, and the embroidery execution head 18, respectively. The main controller stores the workstation cycle table, the handover sequence table, and the buffer occupancy table, and issues control commands accordingly.

[0021] Large-format soft composite fabrics slide forward between workstations using ordinary conveyor rollers. The fabric is prone to micro-slippage due to gravity, localized rebound, and uneven friction, causing the positional reference established at the previous workstation to be unstable and not inherited at the next workstation. At the same time, traditional multi-workstation structures use a uniform mechanical rhythm for rigid synchronization. When a local malfunction occurs in a certain embroidery execution head 18, the entire line needs to be stopped for processing, resulting in unplanned shutdowns of the entire line. This embodiment proposes a device that coordinates segmented tension conveying with independent driving at workstations; the main frame 1 serves as a basic support, and the workstation beams 2 are arranged parallel to the material conveying direction; the fabric support plate 3 is used to carry the fabric, and the transition gap 4 between them is arranged on both sides with a front pressure conveying belt 5 and a rear pressure conveying belt 6; the front conveying servo motor 7 drives the front synchronous belt 8, and the rear conveying servo motor 9 drives the rear synchronous belt 10. The two are independently controlled, forming a segmented traction foundation on both sides of the needle drop area 11; The pressing unit 13 below the pressing beam 12 is used to generate a passive following pressing force to adapt to the fluctuation of fabric thickness. When the local thickness of the fabric increases, the presser foot 14 moves upward along the guide rod 15 and compresses the pre-tension spring 17. At this time, the piston rod of the damping cylinder 16 moves synchronously, and the gas flow resistance inside it suppresses the rapid rebound of the presser foot 14. When the local thickness of the fabric decreases, the presser foot 14 moves downward under the elastic force of the pre-tension spring 17 to follow the fabric surface. The main controller stores a station cycle table to record the action sequence of each station, a handover sequence table to record the task reordering logic when an anomaly occurs, and a buffer occupancy table to record the fabric length status between each station. The main controller issues control commands to the station controllers based on the above tables, and the station controllers drive the front conveyor servo motor 7, the rear conveyor servo motor 9, and the embroidery execution head 18 to move. This structure enables the large soft composite fabric to maintain a stable stress state between each station, and maintains the continuous operation of the other stations when a local anomaly occurs, thereby improving the consistency of pattern matching under continuous production conditions. Maintaining a stable stress state is achieved by at least the following structures: the front timing belt 8 and the rear timing belt 10 are located on the front and rear sides of the needle drop area 11, respectively, forming segmented clamping and traction of the fabric; the pressing unit 13 is arranged at intervals along the width of the fabric, applying distributed downward pressure to the upper surface of the fabric; and the fabric support plate 3 provides continuous support to the lower surface of the fabric. Therefore, the fabric has a clear force constraint path in three stages: before entering the needle drop area 11, within the needle drop area 11, and after leaving the needle drop area 11. Among them, the front pressure feed belt 5 mainly inhibits the front end slippage of the fabric in the forward feeding stage, the rear pressure feed belt 6 mainly inhibits the back slippage after the needle exits, and the pressure holding unit 13 mainly inhibits the local curling and instantaneous rebound of the fabric caused by thickness fluctuations. Therefore, the effect of stable inheritance of position reference does not come from a single component, but from the continuous constraint relationship formed by front and rear segmented traction, upper damping pressure holding, and lower support. The effect of maintaining the continuous operation of other workstations when a local anomaly occurs directly corresponds to the hierarchical control structure of the main controller and the workstation controllers, as well as the joint calling method of the workstation cycle table, the handover sequence table, and the buffer occupancy table. The main controller does not output a single total stop command to the entire line, but instead issues delivery, hold, stop needle, or handover commands to the corresponding workstation controllers according to the workstation number. When a certain workstation malfunctions, the malfunctioning workstation switches to a needle-lifting stop or low-traction passage state, while the non-malfunctioning workstations continue to execute the current cycle or receive the reordered sewing tasks according to their respective workstation cycle tables; thus, the technical effect of maintaining the continuous operation of the remaining workstations in this embodiment has a clear data basis and control path. This embodiment achieves stable force and position reference inheritance during fabric processing by using segmented traction of the front and rear pressure conveyor belts, combined with the upper damping pressure of the pressure holding unit and the lower support of the fabric support plate.

[0022] The outer surfaces of the front synchronous belt 8 and the rear synchronous belt 10 are both fixed with micro-tooth elastic embossed layers; wherein, the micro-tooth elastic embossed layers are made of polyurethane, and the surface of the micro-tooth elastic embossed layers is processed with continuous shallow teeth along the conveying direction.

[0023] To address the issues of high surface hardness of ordinary synchronous belts, which can easily damage composite fabrics, and uneven friction distribution on smooth surfaces, this embodiment fixes a micro-tooth elastic embossed layer on the outer surface of the front synchronous belt 8 and the rear synchronous belt 10. The micro-tooth elastic embossed layer is made of wear-resistant polyurethane material, which constructs a contact interface between rigid support and flexible buffer. The continuous shallow teeth on the surface of the micro-tooth elastic embossed layer are equidistantly arranged along the material conveying direction. When the fabric is subjected to downward pressing force from the pressing unit 13, the micro-toothed elastic embossed layer forms a surface contact friction with the bottom surface of the fabric, and the shallow toothed part is embedded in the fiber gaps of the bottom layer of the fabric. This contact method avoids material damage caused by direct puncture of hard teeth, increases the adhesion friction to the bottom surface of the fabric, and reduces the slippage rate of the fabric during the traction process.

[0024] The embroidery execution head 18 also includes a thread tensioning lever 20, a lever detection plate 21, and a proximity switch 22. The first end of the thread tensioning lever 20 is supported on the head base 23 of the embroidery execution head 18. The lever detection plate 21 is fixedly connected to the thread tensioning lever 20. The proximity switch 22 is fixed to the head base 23 and faces the lever detection plate 21. The proximity switch 22 is electrically connected to the workstation controller. The workstation controller receives the detection signal from the proximity switch 22, converts the detection signal into a sewing confidence level, and transmits the sewing confidence level to the main controller.

[0025] The mattress production workshop contains fiber dust exceeding the preset concentration. Traditional optical vision detection devices are easily contaminated by dust and fail, making it difficult to maintain long-term calibration. In this embodiment, mechanical motion state monitoring is used to replace pure optical recognition. The first end of the tensioning swing rod 20 is supported on the side wall of the head seat 23 by a pin. Under normal sewing conditions, the tensioning swing rod 20 follows the reciprocating motion of the needle bar 19 and swings periodically around the equilibrium position. The pendulum detection plate 21 moves synchronously with the tensioning pendulum 20, periodically entering and leaving the sensing range of the proximity switch 22; the proximity switch 22 converts the sensed physical displacement into a detection signal with alternating high and low levels and sends it to the station controller; the station controller records the edge triggering time and level duration of the detection signal within multiple consecutive stitch beats, and calculates the swing frequency and extreme position dwell time variables of the tensioning pendulum 20. The workstation controller compares the above variables with the preset normal operation benchmark model, calculates the comprehensive deviation rate, and defines the difference between 1 and the comprehensive deviation rate as the sewing reliability and transmits it to the main controller. The purpose of the normal operation benchmark model is to use the movement rhythm of the tensioning lever 20 to characterize whether the yarn tension transmission is continuous without directly observing the appearance of the stitches, thereby distinguishing between normal sewing state and broken, stuck or severely loose state. The normal operation benchmark model logically includes a benchmark data unit, a real-time statistics unit, a deviation evaluation unit, and a confidence output unit. The benchmark data unit stores the benchmark swing frequency range and benchmark dwell time range obtained through debugging and calibration. The real-time statistics unit receives the detection signal of the proximity switch 22 within the current statistical period and extracts the swing frequency and dwell time. The deviation evaluation unit compares the measured values ​​with the corresponding benchmark values ​​item by item to generate a comprehensive deviation rate. The confidence output unit then outputs the seam formation confidence based on the comprehensive deviation rate. The data flow relationship is as follows: the timing signal output by the proximity switch 22 first enters the real-time statistics unit to form motion feature quantity, and then together with the reference feature quantity in the reference data unit, it is sent to the deviation evaluation unit, and the reliability output unit generates the seam reliability for the main controller to call. This model represents the causal relationship of the yarn being pulled by the needle bar 19, the tension being transmitted through the tensioning mechanism, and then being fed back as the change of the swing bar rhythm. When the yarn force transmission is continuous, the swing bar swing frequency and dwell time remain within a stable range. When the yarn breaks, is blocked, or the tension changes suddenly, the swing bar movement rhythm deviates from the normal reference. Therefore, this mechanical motion deviation can be used as an indirect characterization of the stitch forming state. The processing flow of the calculation logic is as follows: The input source is the swing frequency and dwell time within the current statistical period, as well as the reference swing frequency and reference dwell time pre-calibrated in the normal operation reference model; In the high-speed sewing environment, the high-frequency reciprocating impact of the embroidery execution head 18 will cause the tension swing arm 20 to generate periodic mechanical resonance and micro-jumps. This dynamic interference will destroy the physical assumption of ideal smooth swing, causing high-frequency burrs to be mixed into the dwell time signal collected by the proximity switch 22; To eliminate the interference of mechanical resonance, the real-time statistics unit introduces a sliding window midpoint filtering algorithm before extracting the dwell time to filter out extreme values ​​of time abrupt changes caused by mechanical resonance, ensuring that the feature quantity reflects the real yarn tension change rather than the inherent vibration of the mechanical structure. The workstation controller generates a comprehensive deviation rate by weighting and summing the deviation ratios of the oscillation frequency and the reference oscillation frequency, as well as the deviation ratios of the dwell time and the reference dwell time, and then derives the seam formation reliability based on this. The preset weights are calibrated and allocated according to the degree of influence of the equipment debugging stage on the deterioration of the seam formation quality. To avoid misjudgment due to a single shake or occasional dust adhesion, the real-time statistics unit preferably forms a sliding statistics cycle by multiple consecutive stitch beats, and only when the comprehensive deviation rate exceeds the allowable range for multiple consecutive statistics cycles will the seam completion reliability be judged as low reliability. The stitch formation reliability is a dynamic and quantitative state index used to characterize the degree of conformity between the current stitch formation quality and the normal state. It is the key logical judgment basis for the control system to determine whether a break or blockage has occurred. This design does not rely on easily contaminated optical detection devices, but directly binds the yarn force transmission state with the stitch rhythm process, thereby improving the stability of anomaly identification. In this embodiment, the input quantity of the model is limited to a single-channel timing quantity that directly corresponds to the mechanical structure of the device, and its mapping relationship corresponds one-to-one with the physical configuration of the present invention: the proximity switch 22 is installed on the side of the head seat 23 of the embroidery execution head 18 and only detects the in-and-out sensing action of the swing arm detection plate 21 within the predetermined swing angle range. Therefore, the rising edge of the detection signal corresponds to the tension swing arm 20 entering the tension peak range, and the falling edge of the detection signal corresponds to the tension swing arm 20 leaving the range. The duration of the level holding corresponds to the dwell time of the swing arm near the limit position. The oscillation frequency reflects whether the yarn tension transmission is continuous within one or more working cycles of the needle bar 19, and the dwell time reflects whether the swing bar is stuck in an abnormal position due to loose thread, broken thread or jamming. Both of them come directly from the specific combination of the head seat 23, the tensioning swing bar 20, the swing bar detection plate 21 and the proximity switch 22 of this device, rather than from generalizable and replaceable general image features or neural network features. The establishment of the normal operation benchmark model is limited to the equipment factory commissioning or line replacement maintenance stage. The benchmark data is collected using the corresponding model of the embroidery execution head 18, the target mattress composite fabric, and the rated process speed. Preferably, at each workstation, no less than 3 rolls of qualified fabric are continuously collected, and at least 100 stitch cluster cycles of proximity switch 22 timing signals are continuously collected for each roll. The sample confirmed by manual review to have no broken threads, no skipped stitches, and no obvious loose threads is used as the benchmark sample. For the period when broken threads, jamming, or serious loose threads occur, they are kept separately as abnormal control samples to determine the allowable deviation boundary. The reference data unit preferably stores the average reference oscillation frequency, the allowable frequency fluctuation range, the average reference dwell time, and the allowable dwell time fluctuation range separately for each workstation, so as to avoid different workstations sharing the same threshold due to transmission clearance, assembly differences, or fabric rebound differences. When the real-time statistics unit is deployed on site, it first performs installation calibration: under the condition of needle bar 19 running at low speed under no-load, the installation gap between proximity switch 22 and swing bar detection plate 21 is adjusted so that the edge change of one entry sensing and one exit sensing can be stably generated within one standard swing cycle; then, under normal sewing conditions, a short-time calibration sequence is collected, and the swing frequency and dwell time of the current station are compared with the calibration value in the corresponding reference data unit in the first round. Only when both fall within the allowable fluctuation range is the station determined to be able to enter the normal detection state. Therefore, the calculation basis, data source, manual judgment standard, and on-site calibration steps of the seam reliability are all tied to the specific mechanical components of this device and the mattress production environment, thereby avoiding the formation of a general technical description that is detached from the industrial site and lacks specific data mapping relationships. To enable those skilled in the art to complete the program without excessive experimentation, the processing of seam reliability by the workstation controller can be performed according to a fixed cyclic process: in each sampling cycle, the current level of proximity switch 22 is read and written into the timing buffer queue; when the length of the buffer queue reaches the preset statistical window, the rising edge timestamp, falling edge timestamp, and period between adjacent rising edges within the window are extracted. Median filtering is applied to each cycle value and the duration of high-level holding to obtain the swing frequency and dwell time of the current statistical window; then the reference swing frequency, reference dwell time and allowable fluctuation boundary of the corresponding workstation are read to generate the deviation evaluation result; the seam completion confidence is output and uploaded to the main controller through a data message composed of workstation number, timestamp and confidence value; Preferably, the data message includes at least the workstation address field, statistical period field, oscillation frequency field, dwell time field, seam completion reliability field, and anomaly flag field, so that the main controller can perform time-series association and anomaly scheduling by workstation; The conversion rule from the proximity switch 22 detection signal to the seam completion confidence level can adopt a deterministic threshold judgment method rather than an open learning inference method. Specifically, when both the oscillation frequency and the dwell time fall within the corresponding baseline allowable fluctuation range, the workstation controller records the statistical period as a normal period; when either of them exceeds the allowable fluctuation range, it is recorded as a suspected abnormal period; only when multiple consecutive statistical periods are recorded as suspected abnormal periods will the abnormal flag field be set to valid and the corresponding seam completion confidence level be reduced to a range below the preset level. Therefore, the main controller triggers anomaly transfer based on state results with continuous conditions, rather than instantaneous fluctuation results of a single sampling point, thereby forming a stronger causal relationship between the effect of improving the stability of anomaly identification and specific technical means such as sliding statistics, filtering and continuous period determination. To facilitate verification of the applicability of the above detection method to mattress dust conditions compared to the pure optical detection method, the following evaluation method can be adopted: Under the same process speed and the same fabric batch conditions, record the effective signal acquisition rate, manual verification consistency rate and number of false alarms of the proximity switch 22 scheme and the optical detection scheme after continuous operation for a certain processing time; the above evaluation criteria at least provide a comparison method and judgment standard that can be reproduced on site.

[0026] A transition buffer platform 24 is provided between the crossbeams 2 of adjacent workstations; wherein, the transition buffer platform 24 includes a fixed platform 25 and a floating pressure strip 26, the end of the floating pressure strip 26 is slidably engaged with the fixed platform 25 through a short guide rod 27, and a buffer spring 28 is sleeved on the short guide rod 27.

[0027] When the fabric flows between different workstations, the release action of the previous workstation can easily cause the fabric to lose tension locally and arch upwards, affecting the traction accuracy of the next workstation. In this embodiment, a transition buffer platform 24 is arranged between the crossbeams 2 of adjacent workstations. The transition buffer platform 24 also includes a bracket. The fixed platform 25 is fixed to the main frame 1 by the bracket. Multiple floating pressure strips 26 are arranged in parallel along the width direction of the fabric. The lower end face of the floating pressure strip 26 is close to the upper surface of the fabric, and the short guide rod 27 slides vertically in the sliding sleeve of the fixed platform 25. The buffer spring 28 applies a downward preload, causing the floating pressure strip 26 to apply a first preset pressure to the fabric. When the fabric is released from the previous station into the transition gap 4, the floating pressure strip 26 floats up and down with the slight fluctuations of the fabric, absorbing the local relaxation energy of the fabric through the deformation of the buffer spring 28. This structure reduces the local arching phenomenon generated when the fabric is handed over, and introduces a continuous physical damping effect for the position transfer process of the fabric.

[0028] Example 2: like Figure 5 As shown, a control method for a multi-station automatic embroidery device on a mattress production line includes the following steps: S1. Execute the workstation baseline establishment steps, obtain the fabric tail amount of each workstation, and write the fabric tail amount into the workstation cycle table of the corresponding workstation. S2. Execute the normal embroidery steps. The main controller sends the work sequence to the work station controller according to the work station cycle table, controls the front pressure feeder 5, the rear pressure feeder 6 and the embroidery execution head 18 to work together, and obtains the sewing reliability of each work station. S3. Obtain the preset level threshold and determine the relationship between the seam completion confidence and the preset level threshold. S4. If the seam completion reliability is lower than the preset level threshold, the corresponding workstation is determined to be an abnormal workstation. The workstation transfer steps are executed according to the buffer occupancy table and the transfer sequence table, and the adjacent workstations share the seam repair task of the abnormal workstation. If the seam completion reliability is greater than or equal to the preset level threshold, the normal embroidery steps are maintained.

[0029] The control method of this embodiment transforms the physical force basis of the mechanical structure into schedulable system logic. During the system initialization phase, the main controller executes the station benchmark establishment step to obtain the fabric holding trailing amount that characterizes the inherent delayed rebound characteristics of the fabric. This variable is written into the station beat table as the basis for beat compensation, so that each station allocates push duration and waiting duration according to the rebound characteristics of its respective fabric area. In the normal embroidery process, the main controller uniformly issues the work sequence according to the work station cycle table. The front pressure feeder 5, the rear pressure feeder 6 and the embroidery execution head 18 complete the fabric traction and stitch formation under the drive of the work station controller. The work station controller uploads the sewing reliability calculated based on the motion state of the tension swing rod 20 in real time. The main controller continuously performs logical condition judgments, comparing the current seam reliability variable with the preset level threshold set in the memory; whereby the preset level threshold is a quantified safety boundary parameter used to distinguish whether the workstation is experiencing occasional physical fluctuations or a continuous wire breakage fault. This threshold is set by statistically analyzing the lower limit of the sewing reliability under normal, unbroken thread conditions during the equipment debugging phase, while maintaining a certain safety margin. In the control process, the preset level threshold is used as a trigger condition. When the sewing reliability is greater than or equal to the preset level threshold, the current workstation is determined to be in a stable sewing state, and the established operation sequence is maintained. If the sewing reliability is lower than the preset level threshold, it indicates that the yarn path has broken or is severely blocked, and the main controller determines that the workstation is an abnormal workstation. At this time, the system does not trigger an emergency stop command for the entire line. Instead, it calls the buffer occupancy table to obtain the fabric length status between adjacent workstations, and calls the transfer sequence table to obtain the rearrangement logic. It then initiates the workstation transfer step, reassigning the unfinished stitch area of ​​the abnormal workstation to the adjacent workstation. This method transforms fabric springback and local faults into process variables that can be processed by the system, reducing the number of times the entire line stops.

[0030] The steps in S1 for obtaining the fabric trailing amount at each workstation include: controlling the front conveyor servo motor 7 and the rear conveyor servo motor 9 to advance the fabric at a low speed, while controlling the embroidery execution head 18 to perform empty needle rhythmic motion; determining the fabric trailing amount based on the stable displacement time of the fabric in the needle drop area 11 and the displacement completion time of the front conveyor servo motor 7 and the rear conveyor servo motor 9; and writing the difference in fabric trailing amount between adjacent workstations into the buffer occupancy table.

[0031] The fabric trailing amount reflects the delayed rebound performance of the soft composite material after pressure release; the main controller sends a test command to the workstation controller, and the workstation controller drives the front conveyor servo motor 7 and the rear conveyor servo motor 9 to advance the fabric a predetermined distance at a set low speed, while simultaneously driving the needle bar 19 drive motor of the embroidery execution head 18 to perform empty needle reciprocating motion without thread. The workstation controller records the times when the front conveyor servo motor 7 and the rear conveyor servo motor 9 reach the target pulse position as displacement completion time variables. A sensor is installed on the workstation beam 2 at the position corresponding to the needle drop area 11, and the sensor is electrically connected to the workstation controller. At the same time, the sensor monitors the time when the fabric completely stops moving within the needle drop area 11 as the displacement stabilization time variable. The main controller receives the above two time variables and calculates the difference between the displacement stabilization time variable and the displacement completion time variable. Considering that the elastic recovery process of the fabric after the servo motor stops is not uniform but a nonlinear decay process affected by internal friction and structural damping, if the time difference is directly multiplied by the current test speed, it violates the laws of material dynamics, and its ideal constant speed assumption will be destroyed by dynamic decay. Therefore, the main controller has a built-in elastic recovery attenuation coefficient. By multiplying the time difference by the current test speed and the elastic recovery attenuation coefficient, the length compensation value that the fabric continues to release due to the compression and recovery of the composite layer is obtained, which is the fabric trailing amount. The attenuation coefficient is obtained by integrating the fabric rebound displacement curve during the commissioning phase. It represents the equivalent proportional relationship between the average release rate and the conveyor line speed when the fabric transitions from dynamic propulsion to static equilibrium. To make the correspondence between this parameter and the subsequent scheduling logic clearer, the purpose of calculating the fabric tail is to quantify the additional length released by the fabric at each workstation when it transitions from a pressurized conveying state to a natural stable state. This is used to characterize the difference in rebound hysteresis in different workstation areas and serves as a common input for workstation cycle time compensation and buffer margin evaluation. The calculation logic for the fabric trailing amount consists of a time acquisition unit, a speed conversion unit, and a difference writing unit. The time acquisition unit outputs the displacement completion time variable and the displacement stabilization time variable, respectively. The speed conversion unit receives the time difference between the two and combines it with the current test speed and elastic recovery attenuation coefficient to generate the fabric trailing amount for the corresponding station. The difference writing unit then reads the fabric trailing amount of the adjacent station and generates a relative change value, which is written to the buffer occupancy table. The data flow relationship is as follows: first, the station controller collects time data, then the main controller performs length conversion, writes the absolute compensation amount of a single station into the station cycle table, and writes the difference between adjacent stations into the buffer occupancy table. This parameter characterizes the physical relationship between the internal compression layer, elastic layer and surface layer of the fabric after the external propulsion is released, and there is a recovery lag. The more obvious the recovery lag, the more the fabric will continue to release within the preset deformation range after the displacement is completed. Therefore, subsequent workstations need to reserve more sufficient cycle time compensation and buffer length. To avoid amplifying the trailing amount due to test noise, the displacement stabilization moment is preferably defined as the moment when the fabric displacement signal within the needle drop area 11 continuously remains within a preset small fluctuation threshold, rather than the moment of instantaneous stillness. Correspondingly, the difference in trailing amount between adjacent workstations is used to reflect the relative expansion and contraction trend of the fabric at the junction of adjacent workstations. The larger the difference, the more the buffer occupancy margin needs to be calculated in the junction area during transfer or continuous conveying. This step transforms the complex material mechanical deformation into time and length compensation parameters that the control system can directly call. The sensor used to monitor the fabric displacement within the needle drop area 11 is preferably located on the side of the fabric support plate 3 at the corresponding workstation or near the needle drop area 11. Its detection direction is consistent with the material conveying direction, and it is only used to collect the residual displacement of the fabric edge in the conveying direction. In order to avoid the random shaking of the fiber burrs or loose threads at the edge of the soft composite fabric causing the sensor signal-to-noise ratio to be too low and conflicting with the algorithm accuracy, the sensor is specifically a non-contact line laser displacement sensor. The sensor emits a linear light spot with a certain width to cover multiple fibers at the edge of the fabric. The displacement data processing unit has built-in spatial contour smoothing logic to extract the energy centroid of the reflected signal of the linear light spot as the effective position coordinates of the fabric edge, and sends the time when the effective position coordinates reach the standard to the time acquisition unit to filter out high-frequency jumps caused by local fiber deformation. Therefore, the displacement stabilization time is not an abstract statistical parameter, but is bound to the specific arrangement relationship of the front pressure feeding belt 5, the rear pressure feeding belt 6, the fabric support plate 3 and the needle drop area 11 in this invention. Preferably, the later moment when both the conveying servo motor 7 and the rear conveying servo motor 9 reach the target pulse and the speed feedback drops to the zero speed threshold before the displacement is completed is recorded, and the moment when the displacement is stable is recorded when the fabric edge displacement signal remains within the preset small fluctuation threshold for no less than 3 consecutive sampling cycles, thereby filtering out false triggering caused by a single jitter. The process of obtaining the fabric tail amount is preferably performed before each batch of fabric is put into production. The test conditions are limited to the low-speed conveying process under the conditions of the device station, the pre-tightening state of the pressing unit 13, and the corresponding batch of mattress composite fabric. Preferably, each station is tested more than 3 times, and the median or average value of the multiple test results is taken as the fabric tail amount of the station and written into the station cycle table. If the result of a single test deviates from the other results by more than the preset tolerance, it is determined that the test is affected by local wrinkles, temporary slippage, or sensor noise and is discarded. The difference in trailing amount between adjacent workstations is calculated based on data obtained under the same batch, same test speed and same holding settings, so as to ensure that the buffer occupancy table reflects the real relative rebound difference of the workstation handover area, rather than the result of splicing incomparable data under different working conditions. To enable this step to have a directly programmable processing sequence, the station controller and the main controller can interact as follows: The station controller first receives the test speed, test length, sampling period and zero speed threshold parameters issued by the main controller; within this station, it synchronously starts the front conveyor servo motor 7, the rear conveyor servo motor 9, the empty needle cycle drive and the displacement sensor sampling. When both conveyor servo motors reach the target pulse position and the speed feedback drops below the zero speed threshold, the station controller latches the displacement completion time and continues to maintain the displacement sensor sampling; when the fabric edge displacement signal falls within the preset small fluctuation threshold for multiple consecutive sampling cycles, the station controller latches the displacement stabilization time; then, the station number, displacement completion time, displacement stabilization time, current test speed, and valid test flag are packaged and uploaded to the main controller. Based on this, the main controller completes time difference calculation, length conversion, repeated test result filtering, and table entry writing; thus, the data source, processing node, and writing destination are all clearly defined, avoiding the substitution of specific implementation paths with general descriptions such as automatic acquisition or automatic writing. The elastic recovery attenuation coefficient can be obtained by on-site calibration without relying on complex theoretical modeling. Specifically, during the equipment commissioning phase, a target mattress composite fabric is selected, and the fabric is fed at a fixed low speed and then stopped. The residual displacement curve of the fabric edge from the moment of stopping to the moment of stabilization is continuously recorded. The total residual displacement is then converted into the ratio of the displacement that should theoretically have been traveled according to the conveying linear speed in the same period before stopping, and the elastic recovery attenuation coefficient corresponding to this batch of fabric is obtained. Preferably, the coefficients are stored in the parameter table of the main controller according to the fabric type or batch, and the corresponding parameters are called when subsequent batches are online; this calibration method provides clear data collection objects, conversion basis and parameter sources, making the calculation rules for obtaining the fabric trailing amount verifiable; To facilitate verification that the fabric trailing amount can indeed support subsequent cycle time compensation and buffer assessment, the following assessment method can be adopted: Under the same batch of fabric, run multiple consecutive workstation cycles with and without trailing amount compensation, compare the fabric edge offset at the junction of adjacent workstations, the fluctuation range of compression amount of the transition buffer table 24, and the remaining buffer margin during abnormal transfers to determine the consistency of the transfer; the above comparison indicators correspond to the cycle time compensation effect, buffer stability, and transfer judgment accuracy, respectively, thereby establishing a verifiable field evaluation standard for the effect of reducing the number of downtimes and improving transfer stability as stated in the manual.

[0032] The steps in S2 for controlling the coordinated operation of the front pressure feeder 5, the rear pressure feeder 6, and the embroidery execution head 18 include: the front pressure feeder 5 holds the fabric in place, the rear pressure feeder 6 is unloaded, and the front section of the fabric is pulled into the needle drop area 11; when the fabric reaches the starting position of the stitch, the front pressure feeder 5 and the rear pressure feeder 6 simultaneously enter the holding state, and the embroidery execution head 18 completes the stitch cluster; after the stitch cluster is completed, the rear pressure feeder 6 takes over the traction first, and the front pressure feeder 5 releases after a delay, forming an overlapping force period.

[0033] Within a single stitch processing cycle, the main controller achieves a smooth transfer of fabric by adjusting the torque output mode of the front and rear servo motors; the station controller controls the front conveyor servo motor 7 to output rated torque so that the front pressure conveyor belt 5 keeps clamping and pushing the fabric, while controlling the rear conveyor servo motor 9 to reduce the output torque so that the rear pressure conveyor belt 6 is in a slack-following state, smoothly pulling the front section of the fabric into the stitch drop area 11. Both the front conveyor servo motor 7 and the rear conveyor servo motor 9 are equipped with servo encoders, and the servo encoders are connected to the corresponding workstation controllers. When the displacement data fed back by the servo encoders indicates that the fabric has reached the stitch start position, the workstation controller instructs the front conveyor servo motor 7 and the rear conveyor servo motor 9 to enter the position holding mode synchronously. During this period, the embroidery execution head 18 completes the sewing action of a group of stitches. After the stitch cluster sewing is completed, the control logic enters the handover stage; the station controller instructs the conveyor servo motor 9 to restore the rated torque, so that the rear press conveyor belt 6 takes over the traction control of the fabric. At this time, the front conveyor servo motor 7 maintains the rated torque output for a set delay period before entering the release state. The delay period during which the front pressure feeder 5 and the rear pressure feeder 6 simultaneously output traction force constitutes an overlapping force period. This overlapping force period, in conjunction with the damping and falling action of the holding unit 13, maintains the synchronous binding of the fabric surface and bottom layer before the needle leaves the needle drop area 11, reduces the probability of relative movement between the upper and lower layers of the fabric caused by the sudden transfer of a single contact surface, and ensures that the position reference formed in the previous station is stably transferred to the next station.

[0034] The step of performing workstation transfer according to the buffer occupancy table and the transfer sequence table in S4 includes: calculating the current fabric length margin that the transition buffer table 24 before and after the abnormal workstation can accommodate according to the buffer occupancy table, and comparing the length margin with the preset safe conveying threshold; wherein, the safe conveying threshold is a length critical value determined based on the physical capacity limit length of the transition buffer table and the reserved safe buffer length. If the length margin is greater than or equal to the safe conveying threshold, it is determined that there is a length margin. Then, the embroidery execution head 18 of the abnormal station is controlled to lift the needle and stop rotating, the front pressure conveyor belt 5 of the abnormal station is controlled to enter the release state, and the rear pressure conveyor belt 6 of the abnormal station is controlled to enter the low traction state. According to the transfer order table, the stitch area originally planned to be handled by the abnormal workstation is divided into the first half to be filled by the preceding workstation, the second half to be filled by the following workstation, or the stitching to be filled by the adjacent workstation on one side; if there is no length margin, the entire line is stopped and an alarm signal is issued.

[0035] When a workstation is determined to be an abnormal workstation, the main controller reads the relative change value recorded in the buffer occupancy table, and calculates the fabric length margin that the transition buffer table 24 can currently accommodate before and after the abnormal workstation by combining it with the physical travel parameters of the transition buffer table 24. The main controller then compares the length margin with the preset safe conveying threshold. If the length margin variable is less than the safe conveying threshold, it indicates that the buffer space has been exhausted. Continuing to convey will cause the fabric to tear or pile up. The main controller broadcasts a stop command to all workstation controllers and triggers an audible and visual alarm signal. If the length margin variable is greater than or equal to the safe conveying threshold, the main controller issues a transfer command to the workstation controller corresponding to the abnormal workstation. The embroidery execution head 18 also includes a needle bar 19 drive motor, which is electrically connected to the workstation controller and is used to drive the needle bar 19 to reciprocate. In an abnormal workstation, the needle bar 19 drive motor drives the needle bar 19 to move to the upper extreme position and brakes to stop rotation. The front conveyor servo motor 7 cuts off the torque output to release the fabric from the front pressure conveyor belt 5. The rear conveyor servo motor 9 switches to a low-speed, low-torque mode to maintain the basic passing tension of the fabric, thereby turning the workstation from a processing node into a passing passage. The main controller reads the preset rules in the transfer sequence table, splits the data packets of the unfinished processing tasks of the abnormal workstations, generates a new target coordinate set, and assigns it to the preceding workstation to perform the first half of the seam repair, or assigns it to the following workstation to perform the second half of the seam repair, or instructs a single adjacent workstation to perform the step seam repair; this step enables the equipment to continue operating under partial failure conditions through logical scheduling.

[0036] The steps for patching the front half of the fabric from the preceding workstation, patching the back half from the following workstation, or patching the fabric across adjacent workstations on one side include: reading the end position of the most recently completed stitch at the abnormal workstation, the release time of the preceding workstation, and the waiting time of the preceding stitch cluster at the following workstation; determining whether the fabric is currently dominated by the front or the rear traction in the middle of the abnormal workstation based on the order of the stitch end position, release time, and waiting time; if dominated by the front traction, prioritizing the patching task to the following workstation; if dominated by the rear traction, prioritizing the patching task to the preceding workstation. To ensure precise overlap between the patching area and the existing stitch area when an anomaly occurs, the main controller executes boundary inheritance judgment logic. The main controller extracts the coordinate data of the successful stitching of the abnormal station before the anomaly is judged from memory as the stitch end position variable, extracts the timestamp of the previous station's front pressing conveyor belt 5 exiting the overlapping force period as the release time variable, and extracts the duration of the subsequent station in the position holding mode within the current processing cycle as the waiting time variable. The main controller compares the time logic order of the above three variables to infer the stress distribution state of the fabric in the abnormal work station area. Among them, the judgment logic introduces a threshold parameter of reference period, which is a time threshold used to evaluate the stress transmission state of the fabric. Its value comes from the standard consumption of a single normal embroidery stitch beat and reflects the lower limit of the time for the traction force to solidify in the subsequent work station. In order to make the judgment process have clear processing logic and judgment conditions, the purpose of the boundary inheritance judgment logic is to identify which side of the workstation still plays a major role in constraining the position of the fabric in the middle of the abnormal workstation at the moment the anomaly occurs, so as to prioritize the allocation of the sewing task to the side of the workstation that is easier to inherit the existing position reference. The boundary inheritance determination logic structurally includes a status reading unit, a timing comparison unit, a traction dominance determination unit, and a task allocation unit. The status reading unit is responsible for extracting the stitch end position, release time, and waiting time. The timing comparison unit is responsible for comparing the above variables with the reference cycle. The traction dominance determination unit outputs the determination result of whether the previous traction dominance or the subsequent traction dominance is determined based on the comparison result. The task allocation unit then selects whether the previous or subsequent workstation is responsible for the main stitch repair based on the determination result. The data flow relationship is as follows: first, read the processing status data before and after the anomaly occurs, then form the traction direction determination result, and convert the determination result into the assignment instruction of the repair task; this logic represents the causal relationship that when the fabric is subjected to double-sided traction constraint in the area between the front and rear workstations, the clamping and holding state of which side has a stronger inheritance of the central position reference; if one side is still in an effective traction or position holding state, the fabric position in the middle of the abnormal workstation is closer to the reference direction established on that side, and it is easier to maintain the stitch continuity when the repair is undertaken by the adjacent workstation on that side. If the timestamp corresponding to the stitch end position variable is earlier than the release time variable, and the waiting time variable is lower than the baseline period, it means that the subsequent workstation has not yet entered a long-term position locking state, and the position of the front part of the fabric has not been stably locked. In the operation of multiple workstations, due to the difference in the elastic modulus of the fabric and the dynamic floating of the transition buffer platform 24, the internal tension transmission of the fabric is delayed. The ideal rigid body assumption based solely on the timestamp will contradict the complex physical environment of the flexible fabric. Therefore, in the above boundary inheritance judgment logic, before determining the traction dominance, the main controller compensates for the dynamic tension hysteresis of the fabric based on the difference in fabric tail amount in the buffer occupancy table; the preset difference threshold is calibrated by statistically analyzing the upper limit of the difference in tail amount between adjacent workstations under normal traction during the equipment debugging phase; when the difference in fabric tail amount is greater than the preset difference threshold, it indicates that the elastic deformation of the fabric exceeds the preset range, and the main controller dynamically extends the reference period proportionally to absorb the tension fluctuation interference of the fabric at the junction of the front and rear workstations. The timing comparison unit executes the following structured decomposition rules: the standard sewing time during normal system operation is set as the base reference cycle; the absolute value of the difference in fabric trailing amount between the current workstation and its adjacent workstation is extracted; this value is divided by the maximum allowable trailing difference calibrated during the equipment debugging phase to calculate a dimensionless hysteresis coefficient between 0 and 1; this hysteresis coefficient is multiplied by the maximum compensation time preset by the system; and the resulting product is added to the base reference cycle as the target compensation cycle after dynamic update; and subsequent timing relationship comparisons are performed based on this target compensation cycle. The rule clearly defines the calculation boundary for converting physical hysteresis of the fabric into time compensation. By coupling the timing determination of mechanical actions with the physical deformation characteristics of the fabric, the main controller can more accurately determine that the current fabric is dominated by the traction of the previous section and the fabric position mainly inherits the benchmark established by the previous station. At this time, the main controller packages the main part of the seam repair task and sends it to the subsequent station for execution. The previous station is only responsible for sending the overlap boundary into the transition buffer table 24. If the judgment logic results in the opposite sequence, the main controller determines that the current fabric is dominated by the traction of the rear section. The main controller packages the main part of the seam repair task and sends it to the preceding workstation for execution. The following workstation then performs the action of releasing the overlap space. When the timing comparison result is in the fuzzy range near the reference cycle, the task allocation unit preferably uses the distance between the end point of the most recently completed stitch at the abnormal workstation and the center of the area to be repaired as an auxiliary judgment. If the end point of the stitch is closer to the second half of the area, it is assigned to the subsequent workstation first; if it is closer to the first half of the area, it is assigned to the previous workstation first, so as to reduce the length of cross-area repair and reduce the overlap deviation. This judgment logic finds the stable reference direction of the fabric based on the traction dominance relationship in the existing workstation timing, avoiding the problem of inconsistent residual rebound caused by directly crossing with a large step. The boundary inheritance judgment logic is a deterministic timing judgment rule that directly corresponds to the conveying and handover structure of this invention; the needle end position comes from the coordinate cache of the most recent successful needle drop of the embroidery execution head 18 in the abnormal station; the release time comes from the release timestamp of the end of the overlapping force period of the front pressing conveyor belt 5 of the previous station; the waiting time comes from the duration record of the previous needle cluster in the position holding mode of the subsequent station. The above three input quantities correspond to the abnormal workstation stitch boundary, the front traction release node, and the rear traction solidification degree, respectively. They are all directly mapped to the action states of the front pressure feeding belt 5, the rear pressure feeding belt 6, the embroidery execution head 18, and the transition buffer table 24. Therefore, this judgment rule does not have independent universality after leaving the workstation structure and timing control relationship of the present invention. The baseline cycle is preferably obtained by collecting data during the equipment debugging phase under normal embroidery conditions. The data collection objects are multiple stitch cluster cycles continuously completed by each workstation under rated process parameters, and the statistical value of the cycle without broken thread, abnormal transfer, or obvious rebound instability is used as the standard time benchmark. Preferably, the main controller records the distribution range of the release timestamp of the previous workstation and the position holding time of the subsequent workstation within at least dozens of normal cycles, and sets the reference cycle and fuzzy interval boundary accordingly, so that the traction-dominant judgment when an anomaly occurs has a clear on-site calibration source; thus, the priority allocation of the patching task is neither an abstract rule selection nor an algorithm module that can be arbitrarily reused without operating conditions, but an industrially reproducible decision logic based on the actual workstation cycle time, actual traction handover events and on-site debugging data of this device.

[0037] Before step S1, there is also a pressure pre-adjustment step: control the pressure beam 12 to descend to the reference height, control the damping cylinder 16 to maintain a uniform low pressure; advance the fabric of the test length at a low speed; adjust the air throttling degree of the damping cylinder 16 of the corresponding station according to the amount of fabric tail formed in the test length at each station. Different batches of composite fabrics have differences in thickness distribution and elastic coefficient, requiring adaptive adjustment of the mechanical pressing components; before each batch of fabric is formally processed, the two ends of the pressing beam 12 are lifted and set on the main frame 1 by guide columns. The device is also equipped with a lifting drive mechanism that communicates with the control system and is used to drive the guide columns to rise and fall. In addition, the device also includes a pneumatic proportional valve controlled by the main controller, and an electromagnetic throttle valve installed on the exhaust circuit of the damping cylinder 16; the main controller controls the guide column to drive the pressure beam 12 to descend to the preset reference height coordinate, and controls the pneumatic proportional valve to output a uniform low-pressure airflow to each damping cylinder 16, so that the damping cylinder 16 maintains the initial light-load damping state. The main controller instructs the conveying system to advance a section of fabric of a set test length in low-speed mode, so that the fabric passes through the front pressure conveyor belt 5 and the rear pressure conveyor belt 6 of each station in sequence; the main controller collects the amount of fabric tailing calculated by each station during this test. The main controller maps the amount of fabric tail to a damping adjustment command: for a workstation where the amount of fabric tail is greater than the first preset length threshold, it indicates that the fabric rebound release rate in that area is lower than the preset rate. The main controller outputs a control signal to reduce the opening of the electromagnetic throttle valve on the exhaust circuit of the corresponding damping cylinder 16, thereby increasing the cylinder damping and extending the time that the presser foot plate 14 is in contact with the fabric surface. For workstations where the fabric tail length is less than the second preset length threshold, the main controller outputs a control signal to increase the opening of the electromagnetic throttle valve, reduce the cylinder damping, and reduce the drag resistance of the presser foot plate 14 on the fabric surface. This step directly matches dynamic parameters based on the physical response of the fabric during the conveying action, so as to achieve synergy between the mechanical structure characteristics and the control algorithm parameters.

[0038] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A multi-station automatic embroidery device for a mattress production line, comprising: The main frame (1) has a work station crossbeam (2) parallel to the conveying direction, on which a cloth support plate (3) is fixed, and a transition gap (4) is formed between adjacent cloth support plates (3). The feature is that a front pressure conveyor belt column (5) and a rear pressure conveyor belt column (6) are respectively arranged on both sides of the transition gap (4). The front press conveyor belt (5) includes a front synchronous belt (8) driven by a front conveyor servo motor (7); the rear press conveyor belt (6) includes a rear synchronous belt (10) driven by a rear conveyor servo motor (9); and a needle drop area (11) is left between the front synchronous belt (8) and the rear synchronous belt (10). A pressing beam (12) is provided above the workstation beam (2), and a pressing unit (13) is provided at intervals on the lower side; the pressing unit (13) includes a pressing foot plate (14), a guide rod (15), a damping cylinder (16) and a preload spring (17). The pressing foot plate (14) is slidably connected to the pressing beam (12) via the guide rod (15). The preload spring (17) is between the pressing beam (12) and the pressing foot plate (14). The cylinder body of the damping cylinder (16) is fixed to the pressing beam (12), and the piston rod is hinged to the pressing foot plate (14). The workstation beam (2) has a fixed embroidery execution head (18) with a needle bar (19) in the middle. The movement area of ​​the needle bar (19) is above the needle drop area (11). The device includes a workstation controller and a main controller with communication connection. The workstation controller is electrically connected to the front conveying servo motor (7), the rear conveying servo motor (9) and the embroidery execution head (18) respectively. The main controller stores the workstation cycle table, the handover sequence table and the buffer occupancy table, and issues control commands accordingly.

2. The multi-station automatic embroidery device on a mattress production line according to claim 1, characterized in that, The outer surfaces of the front synchronous belt (8) and the rear synchronous belt (10) are both fixed with micro-tooth elastic embossing layers; wherein, the micro-tooth elastic embossing layer is made of polyurethane, and the surface of the micro-tooth elastic embossing layer is processed with continuous shallow teeth along the conveying direction.

3. The multi-station automatic embroidery device on a mattress production line according to claim 1, characterized in that, The embroidery execution head (18) also includes a thread tensioning lever (20), a lever detection plate (21), and a proximity switch (22); wherein, the first end of the thread tensioning lever (20) is supported on the head base (23) of the embroidery execution head (18), the lever detection plate (21) is fixedly connected to the thread tensioning lever (20), the proximity switch (22) is fixed to the head base (23) and faces the lever detection plate (21), and the proximity switch (22) is electrically connected to the workstation controller; the workstation controller receives the detection signal from the proximity switch (22), converts the detection signal into a sewing confidence level, and transmits the sewing confidence level to the main controller.

4. The multi-station automatic embroidery device for a mattress production line according to claim 1, characterized in that, A transition buffer platform (24) is provided between the adjacent workstation beams (2); wherein the transition buffer platform (24) includes a fixed platform (25) and a floating pressure strip (26), the end of the floating pressure strip (26) is slidably engaged with the fixed platform (25) through a short guide rod (27), and a buffer spring (28) is sleeved on the short guide rod (27).

5. A control method for a multi-station automatic embroidery device on a mattress production line, characterized in that, A control method for a multi-station automatic embroidery device applied to a mattress production line according to any one of claims 1 to 4, comprising the following steps: S1. Execute the workstation baseline establishment step, obtain the fabric tail amount of each workstation, and write the fabric tail amount into the workstation cycle table corresponding to the workstation. S2. Perform normal embroidery steps. The main controller sends the work sequence to the work station controller according to the work station cycle table, controls the front pressing conveyor belt (5), the rear pressing conveyor belt (6) and the embroidery execution head (18) to work together, and obtains the sewing reliability of each work station. S3. Obtain a preset level threshold and determine the relationship between the seam formation reliability and the preset level threshold. S4. If the seam completion reliability is lower than the preset level threshold, the corresponding workstation is determined to be an abnormal workstation. The workstation transfer step is performed according to the buffer occupancy table and the transfer order table, and the adjacent workstations share the seam repair task of the abnormal workstation. If the seam completion reliability is greater than or equal to the preset level threshold, the normal embroidery step is maintained.

6. The control method for the multi-station automatic embroidery device on a mattress production line according to claim 5, characterized in that, The step of obtaining the fabric trailing amount of each workstation in S1 includes: controlling the front conveying servo motor (7) and the rear conveying servo motor (9) to advance the fabric at a low speed, while controlling the embroidery execution head (18) to perform empty needle rhythm movement; determining the fabric trailing amount based on the displacement stabilization time of the embroidery execution head (18) and the displacement completion time of the front conveying servo motor (7) and the rear conveying servo motor (9); and writing the difference in the fabric trailing amount between adjacent workstations into the buffer occupancy table.

7. The control method for the multi-station automatic embroidery device on a mattress production line according to claim 5, characterized in that, The steps in S2 for controlling the coordinated operation of the front pressure feeder (5), the rear pressure feeder (6), and the embroidery execution head (18) include: the front pressure feeder (5) holds the fabric in place, the rear pressure feeder (6) is unloaded, and the front section of the fabric is pulled into the needle drop area (11); when the fabric reaches the starting position of the stitch, the front pressure feeder (5) and the rear pressure feeder (6) simultaneously enter the holding state, and the embroidery execution head (18) completes the stitch cluster; after the stitch cluster is completed, the rear pressure feeder (6) takes over the traction first, and the front pressure feeder (5) releases after a delay, forming an overlapping force period.

8. The control method for the multi-station automatic embroidery device on a mattress production line according to claim 5, characterized in that, The multi-station automatic embroidery device is the device described in claim 4. The step of performing station transfer according to the buffer occupancy table and the transfer sequence table in step S4 includes: calculating the current fabric length margin that the transition buffer platform (24) before and after the abnormal station can accommodate according to the buffer occupancy table, and comparing the length margin with a preset safety transport threshold; wherein, the safety transport threshold is a length critical value determined based on the physical capacity limit length of the transition buffer platform and the reserved safety buffer length; If the length margin is greater than or equal to the safe conveying threshold, it is determined that there is a length margin. Then, the embroidery execution head (18) of the abnormal station is controlled to lift the needle and stop rotating, the front pressure conveyor belt (5) of the abnormal station is controlled to enter the release state, and the rear pressure conveyor belt (6) of the abnormal station is controlled to enter the low traction state. According to the transfer sequence table, the stitch area originally planned to be handled by the abnormal workstation is divided into the first half to be filled by the preceding workstation, the second half to be filled by the following workstation, or the stitching to be filled by the adjacent workstation on one side; if there is no length margin, the entire line is stopped and an alarm signal is issued.

9. The control method for the multi-station automatic embroidery device on a mattress production line according to claim 8, characterized in that, The steps of patching the first half of the seam by the preceding workstation, patching the second half of the seam by the following workstation, or patching the seam by a single adjacent workstation include: reading the end point position of the most recently completed stitch at the abnormal workstation, the release time of the preceding workstation, and the waiting time of the preceding stitch cluster at the following workstation. Based on the sequence of the stitch end point position, the release time, and the waiting time, determine whether the current fabric is dominated by the front traction or the rear traction in the middle of the abnormal work station; if it is dominated by the front traction, the repair task is preferentially assigned to the subsequent work station; if it is dominated by the rear traction, the repair task is preferentially assigned to the previous work station.

10. The control method for the multi-station automatic embroidery device on a mattress production line according to claim 5, characterized in that, Before step S1, a pre-adjustment step is also included: controlling the pressing beam (12) to descend to the reference height, controlling the damping cylinder (16) to maintain a uniform low pressure; advancing the fabric of the test length at a low speed; adjusting the air throttling degree of the damping cylinder (16) corresponding to the work station according to the amount of fabric trailing formed in the test length at each work station.

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