PCB mainboard for loom without stopper detection

Abstract

This invention discloses a dedicated PCB motherboard for detecting warp breaks without stopping on a loom, comprising a substrate, a horizontally opposed infrared laser emitting / receiving unit, a photoelectric signal conditioning circuit, a loom spindle acquisition circuit, a main control circuit, and a power supply EMC protection circuit. The horizontally opposed infrared laser emitting / receiving unit uses a JAN9410-001 type 940nm laser diode with an optical path length of 10 / 15mm, supporting two selectable operating modes: a default 5.5 / 10mW constant continuous emission mode and an optional 2mW low-power + spindle synchronization gap emission mode. This invention breaks through industry technical biases, utilizing the advantage of a short optical path to achieve reliable low-power detection, extending the laser tube's lifespan from 1.14 years to 8-12 years, reducing the false detection rate by over 60%, and extending the motherboard's MTBF to 20,000 hours, perfectly adapting to the high humidity and high salt spray textile conditions of the Nantong coastal area.

Description

Technical Field

[0001] This invention relates to the field of textile machinery electronic technology, and in particular to a dedicated PCB motherboard for detecting warp breaks without stopping on a loom.

[0002] Same-day application related explanation This application is one of a series of invention patents filed by the applicant on the same day, titled "Woven Warp Detection System for Looms with No Stoppages." This series of patents shares the same core inventive concept: using non-contact laser technology to achieve end-to-end reliability assurance for the detection of undisturbed warp pieces on looms. This series of patents includes seven invention patents, each addressing one of the seven interrelated and indispensable technical aspects of the menopause detection system: 1. Dedicated PCB motherboard for detecting warp breaks without stopping on a loom (hardware basics) 2. Adaptive calibration control method, system, and storage medium (calibration algorithm) for the entire lifecycle of warp-stop detection on looms. 3. Multi-level anti-interference and error prevention control method, system, and storage medium (anti-interference technology) for the entire chain of warp-stopping segment detection on looms. 4. Hardware-level safety interlock state machine control system for detecting warp breaks on the loom (safety control) 5. LoRa Mesh cluster management method, system, and storage media for looms with non-stop warp beam warp breakage detection devices (cluster management) 6. A control system and method for main shaft synchronization time slot scheduling and dual-path hardware split control for warp breakage detection in a non-stop warp beam loom (underlying communication). 7. A non-contact intelligent warp breakage detection and end-to-end integrated production management system for all types of shuttleless looms (production integration) There is a clear technical dependency among the various patented technical solutions, which together solve the overall technical problems of the non-stop-flow segment detection system, namely "poor real-time performance, low reliability, and weak adaptability," and comply with the unity requirement stipulated in the Patent Law. Background Technology

[0004] In the field of water-jet looms, stop-warp clips suffer from problems such as cumbersome yarn threading, easy sticking and jamming, warp wear, and slow detection response. In the field of air-jet looms, stop-warp clip detection has a fundamental compatibility defect—air-jet looms are often used to produce high-value-added ultra-fine denier yarns such as 10D and 20D. The metal edge of the stop-warp clip can directly scratch and fuzz the ultra-fine denier warp yarn, causing warp fuzzing, frequent warp breaks, and a 20%-30% decrease in yield, becoming an industry pain point in the high-end fine denier yarn weaving field. In recent years, a few auxiliary technologies based on photoelectric detection have emerged in the industry, but none of them have broken away from the technical framework of warp breakage sheets. They can only indirectly detect the falling state of the warp breakage sheets, and there is no mature PCB motherboard solution that directly uses a photoelectric beam to perform non-contact warp breakage detection on the warp yarn itself. Existing experimental photoelectric detection PCB motherboards have the following core defects: Infrared / laser emitting tubes generally adopt a constant continuous emission mode of 5~10mW. Under the harsh working conditions of high temperature, high humidity and high salt spray in coastal textile workshops, the laser tube light decays very quickly, with an average service life of only 1.14 years. Frequent replacement is required, and the annual maintenance cost of a single loom is about 150-200 yuan. In the high-temperature and high-humidity environment of textile workshops, the background noise changes significantly over time, leading to a decrease in detection accuracy. The false detection rate of existing solutions is generally between 1.5% and 2%. Poor circuit design and electromagnetic compatibility performance can lead to signal distortion and affect detection stability due to strong electromagnetic interference generated by the loom frequency converter. Without synchronous detection of the loom spindle timing, it is impossible to accurately determine the time and location of warp breakage, which can easily lead to missed detection. The power supply protection is insufficient, the power grid in the textile workshop fluctuates frequently, and surge voltage can easily damage the motherboard. The mean time between failures (MTBF) of the existing motherboard is only about 8,000 hours. Summary of the Invention

[0005] The technical problem to be solved by this invention is that existing looms have problems such as short lifespan of laser tube on PCB motherboard for detecting warp-stop segments, poor background noise suppression, serious electromagnetic interference, low detection accuracy, insufficient power supply protection, and limited working modes. Technical solution

[0006] To solve the above-mentioned technical problems, the present invention provides a dedicated PCB motherboard for detecting warp fragments without stopping in a loom, including a substrate, a horizontally opposed infrared laser emitting / receiving unit integrated on the substrate, a photoelectric signal conditioning circuit, a loom spindle acquisition circuit, a main control circuit, and a power supply EMC protection circuit.

[0007] The horizontally opposed infrared laser transmitting / receiving unit uses a 940nm infrared laser emitting tube and supports three selectable working modes: default 2mW spindle synchronous multi-level intermittent transmission mode, selectable 5.5~10mW constant continuous transmission mode, and selectable 2mW low-power single-rotation intermittent transmission mode.

[0008] The photoelectric signal conditioning circuit includes a gain-adjustable amplifier that can automatically adjust the amplification factor according to the laser emission power to ensure the signal-to-noise ratio in low-power mode.

[0009] The main control circuit adopts a structure combining a hardware comparator, a timing synchronization trigger, and a background noise register to achieve periodic background noise cancellation. At the same time, the timing synchronization trigger can control the emission timing of the laser tube, realizing synchronous multi-level gap emission of the spindle. Beneficial effects

[0010] Compared with the prior art, the present invention has the following outstanding and substantial beneficial effects: The lifespan of the laser tube has been greatly improved: by adopting a 2mW low-power emission mode with a synchronous gap of 5 spindle revolutions, the laser tube's lifespan in industrial applications can conservatively reach 7-9 years, which is close to the design life of the loom. This significantly reduces the maintenance frequency and reduces the maintenance cost of a single loom by more than 85% over its entire life cycle. Strong background noise suppression capability: By adopting a hardware comparator combined with timing synchronization periodic background noise cancellation technology, the false detection rate can be reduced to below 0.5% after 1000 hours of continuous operation in a high temperature and high humidity environment of 85℃ / 85% RH. Electromagnetic interference is significantly reduced: Low power + gap emission reduces the overall power consumption of the motherboard by 60%, reduces electromagnetic interference generated by the infrared emission circuit by 70%-80%, and reduces signal crosstalk by 45%; Strong power protection capability: Adopting a multi-level EMC protection structure, the motherboard's mean time between failures (MTBF) can be extended to 18,000-20,000 hours, and the service life is increased to more than twice the original. Flexible working modes: Supports three working modes, which can be adapted to various looms of high speed, medium speed and low speed, taking into account both detection response speed and service life; Flexible communication interfaces: Supports multiple communication interfaces such as RS485, CAN, UART, and LoRa, and can be directly connected to various loom main control systems and cluster management systems, with extremely strong adaptability; Outstanding innovation: It breaks the industry's technical prejudice that "the higher the power, the more reliable the detection," and utilizes the unique advantage of a horizontally opposed short optical path to achieve reliable detection at low power. There is no inspiration for this approach in existing technologies. Attached Figure Description

[0011] Figure 1 This is an overall structural block diagram of the hardware device described in an embodiment of the present invention; In the diagram: 1. Main control module, 2. Power supply EMC protection module, 3. Beam emission drive module, 4. Photoelectric signal conditioning module, 5. Loom spindle acquisition module, 6. Safety interlock stop module, 7. Hardware watchdog module, 8. LoRa wireless communication module.

[0012] Figure 2 This is a circuit structure block diagram of the power supply EMC protection module according to an embodiment of the present invention; In the diagram: 1. External industrial power input, 2. Reverse connection protection circuit, 3. Surge suppression circuit, 4. Common mode filter circuit, 5. Differential mode filter circuit, 6. Linear voltage regulator circuit, 7. System regulated output.

[0013] Figure 3 This is a circuit structure block diagram of the photoelectric signal conditioning module described in an embodiment of the present invention; In the figure: 1. Original photoelectric detection signal waveform, 2. Standard signal waveform after double outlier removal.

[0014] Figure 4 This is a structural block diagram of the PCB motherboard main controller docking circuit according to an embodiment of the present invention; In the diagram: 1. PCB motherboard carrier, 2. Industrial-grade embedded microcontroller, 3. Signal amplification and conditioning circuit, 4. Non-volatile memory circuit, 5. Reset and hardware watchdog circuit, 6. Darlington transistor drive circuit, 7. Normally closed spindle angle detection component, 8. Loom main control system. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is based on the actual working conditions of a water jet loom in a textile factory in Nantong, Jiangsu Province, and the entire process was tested and verified. Those skilled in the art can repeat this embodiment.

[0016] In this embodiment, a JAN9410-001 type 940nm infrared laser emitting tube is preferably used, and the main control circuit is preferably an STM32F407VET6 or STM32F103ZET6 type 32-bit ARM microcontroller. Those skilled in the art will understand that other devices with the same performance parameters can also implement the technical solution of this invention.

[0017] The basis for accurate calculation of laser tube lifespan: Basic lifespan: 5.5mW. In continuous emission mode, the nominal lifespan of the JAN9410-001 laser tube is 10,000 hours. Power-to-lifetime conversion: Based on conventional empirical models in this field, in the low power range of 2~10mW, the lifespan of the laser tube is approximately inversely proportional to the output power. Therefore, the theoretical lifespan in the 2mW continuous emission mode is (5.5 / 2)×10000=27500 hours≈3.14 years. Intermittent emission duty cycle: The loom spindle rotates 360° in one revolution, of which the stable warp yarn shedding range is 80°~270°, totaling 190°, accounting for approximately 52.78% of a single revolution cycle; when using the intermittent mode of emitting once every 5 revolutions, the actual working duty cycle of the laser tube is approximately 10.56% (52.78% / 5). Final theoretical lifespan: 27,500 hours / 0.1056 ≈ 260,400 hours ≈ 29.7 years; considering the impact of harsh environmental factors such as high temperature, high humidity and dust in textile workshops on the lifespan of laser tubes, a conservative value of 7-9 years for industrial applications is taken.

[0018] This embodiment represents the system's default operating mode, suitable for most medium- and low-speed looms (speed < 800 rpm), balancing detection accuracy and laser tube lifespan.

[0019] The laser diode 8 in the horizontally opposed infrared laser emitting / receiving unit 1 has its operating power adjusted to 2mW and operating current to 4.5mA. The timing synchronization trigger 10 controls the laser diode 8 to emit once every 5 weaving cycles. The duration of each emission corresponds exactly to the stable warp opening range 11 of the main shaft from 80° to 270°. At a speed of 600rpm, each emission lasts for 0.0528 seconds. During non-detection intervals, the laser diode 8 is completely turned off, and the duty cycle is 1 / 5.

[0020] The gain-adjustable amplifier in the photoelectric signal conditioning circuit 3 automatically adjusts the amplification factor to 180 times to compensate for the signal attenuation caused by low power, ensuring that the signal-to-noise ratio is comparable to that of the 5.5mW constant-on mode.

[0021] The loom spindle acquisition circuit 4 acquires the sine wave signal output by the loom spindle encoder, converts it into a standard square wave timing pulse signal after photoelectric isolation and pulse shaping, and inputs it to the timing synchronization trigger 10 of the main control circuit 5.

[0022] In each emission cycle, the timing synchronization trigger 10 of the main control circuit 5 triggers a hardware comparator to perform a difference calculation between the light intensity signal of the current cycle and the background noise signal of the previous cycle within the stable warp opening range 11 of the main axis from 80° to 270°. If the difference exceeds a preset threshold, it is determined to be a warp breakage, triggering the warp breakage alarm output circuit 6 to control the loom to stop and issue an audible and visual alarm.

[0023] In this mode, the laser tube has a conservative lifespan of 7-9 years for industrial applications, the overall power consumption of the mainboard is reduced by 60%, the response time for warp breakage detection is ≤50ms, and the detection accuracy is 99.97%, which fully meets the detection needs of medium and low speed looms.

[0024] This embodiment is an optional high-speed mode, suitable for high-speed water jet looms with a rotation speed of ≥800rpm, and has the fastest detection response speed.

[0025] The horizontally opposed infrared laser emitting / receiving unit 1 uses a JAN9410-001 type 940nm laser diode 8, with a working power of 5.5mW, a working current of 12mA, and constant continuous emission. Each set of laser emitting diodes 8 and infrared receiving diodes 9 are respectively mounted on the upper and lower sides of the substrate, with their central axes coinciding and an optical path length of 12mm.

[0026] The gain-adjustable amplifier in the photoelectric signal conditioning circuit 3 is set to 100 times to amplify, filter and rectify the weak photoelectric signal output by the infrared receiver tube 9, and output a full-time domain light intensity analog signal to the main control circuit 5.

[0027] In this mode, the laser tube has a lifespan of approximately 3 years, a breakage detection response time of ≤10ms, and a detection accuracy of 99.98%.

[0028] This embodiment is an optional ultra-long life mode, suitable for low-speed rapier looms with a speed of ≤400rpm and remote factories with extremely low maintenance requirements.

[0029] The timing synchronization trigger 10 controls the laser tube 8 to emit once every 10 weaving cycles, reducing the duty cycle to 1 / 10. The laser tube's lifespan for industrial applications can conservatively reach 12-14 years or more.

[0030] The gain-adjustable amplifier in the photoelectric signal conditioning circuit 3 automatically adjusts the amplification factor to 200 times to ensure the signal-to-noise ratio.

[0031] In this mode, the response time for broken vein detection is ≤100ms, the detection accuracy is 99.95%, and long-term maintenance-free operation is achieved.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dedicated PCB motherboard for detecting warp breaks without stopping on a loom, characterized in that, include: substrate; A horizontally opposed infrared laser emitting / receiving unit integrated on the substrate is used to obtain photoelectric signals by detecting the horizontal displacement of warp yarns caused by warp breakage and winding. The photoelectric signal conditioning circuit, electrically connected to the horizontally opposed infrared laser transmitting / receiving unit, includes a preamplifier circuit, a gain-adjustable amplifier, a bandpass filter circuit, and a full-wave rectifier circuit connected in sequence, for amplifying, filtering, and rectifying the photoelectric signal to output a full-time-domain light intensity analog signal; The loom spindle acquisition circuit is electrically connected to the loom spindle encoder and is used to acquire the rotation angle signal of the loom spindle and convert it into a timing pulse signal. The main control circuit is electrically connected to the photoelectric signal conditioning circuit and the loom spindle acquisition circuit. It includes a hardware comparator, a timing synchronization trigger and a background noise register. The timing synchronization trigger triggers the hardware comparator according to the timing pulse signal to perform a difference operation between the current period's full-time domain light intensity analog signal and the previous period's background noise signal stored in the background noise register, thereby achieving periodic background noise elimination. The power supply EMC protection circuit is electrically connected to each of the above circuits to provide a stable DC power supply and suppress electromagnetic interference. The horizontally opposed infrared laser transmitting / receiving unit uses a 940nm infrared laser emitting tube and supports three selectable working modes: default 2mW spindle synchronous multi-level intermittent transmission mode, selectable 5.5~10mW constant continuous transmission mode, and selectable 2mW low-power single-rotation intermittent transmission mode.

2. The PCB motherboard according to claim 1, characterized in that, The optical path length of the horizontally opposed infrared laser emitting / receiving unit is 10~15mm, and it includes multiple sets of infrared laser emitting tubes and infrared receiving tubes. Each set of infrared laser emitting tubes and infrared receiving tubes is installed on the upper and lower sides of the substrate respectively and their central axes coincide, forming a horizontally opposed optical path structure.

3. The PCB motherboard according to claim 1, characterized in that, The nominal output power of the 940nm infrared laser emitter is 2~10mW.

4. The PCB motherboard according to claim 1, characterized in that, The multi-level intermittent emission mode supports configurable frequency-division synchronous emission based on the rotation of the loom spindle. The duration of each emission is strictly limited within the stable warp yarn opening range of 80° to 270° of the spindle, and the laser diode is completely turned off outside the detection range.

5. The PCB motherboard according to claim 1, characterized in that, The gain-adjustable amplifier is used to automatically adjust the signal amplification factor according to different warp yarn materials and laser emission power; when using the 2mW low power mode, the gain-adjustable amplifier automatically adjusts the amplification factor to 150~200 times to ensure that the signal-to-noise ratio is not lower than 5.5mW constant light mode.

6. The PCB motherboard according to claim 1, characterized in that, The loom spindle acquisition circuit includes an opto-isolator and a pulse shaping circuit. The opto-isolator is used to isolate strong electrical interference from the loom, and the pulse shaping circuit is used to convert the acquired sine wave signal into a standard square wave timing pulse signal.

7. The PCB motherboard according to claim 1, characterized in that, The main control circuit uses a 32-bit ARM microcontroller, the hardware comparator uses a high-speed analog comparator built into the microcontroller, and the background noise register uses an SRAM storage unit built into the microcontroller.

8. The PCB motherboard according to claim 1, characterized in that, It also includes a menstrual break alarm output circuit, which is electrically connected to the main control circuit and is used to output a relay control signal and an audible and visual alarm signal when a menstrual break signal is detected.

9. The PCB motherboard according to claim 1, characterized in that, It also includes a communication interface circuit, which is electrically connected to the main control circuit. The communication interface circuit includes at least one of RS485 interface, CAN bus interface, UART interface, and LoRa interface, and is used for data communication with the loom main control system, host computer, and cluster management system.

10. The PCB motherboard according to claim 1, characterized in that, The substrate adopts an FR-4 four-layer board structure, including a top signal layer, a ground layer, a power layer, and a bottom signal layer. The signal lines of the horizontally opposed infrared laser emitting / receiving unit are arranged on the top signal layer and the bottom signal layer, using a differential routing method.

11. The PCB motherboard according to claim 1, characterized in that, The power supply EMC protection circuit includes a fuse, a varistor, a common-mode inductor, and a differential-mode capacitor connected in sequence to suppress surge voltage and electromagnetic interference on the power line.

12. A device for detecting warp breaks without stopping on a loom, characterized in that, Includes the PCB motherboard as described in any one of claims 1-11, and a mounting bracket mounted on the warp beam of a loom, wherein the PCB motherboard is fixed on the mounting bracket.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium is a non-volatile computer-readable storage medium selected from at least one of Flash chips, hard disks, SD cards, and eMMC; the storage medium is configured to be used in conjunction with the dedicated PCB motherboard for detecting non-stop warp segments of a loom as described in claim 1, and stores computer-executable instructions, which, when executed by a processor, implement the control logic of the PCB motherboard.

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