Real-time monitoring system for electrospinning equipment

Abstract

This invention provides a real-time monitoring system for an electrospinning device. The electrospinning device includes: N spinning units, N≥2; each spinning unit extends multiple spinning needles; the real-time monitoring system includes: an image acquisition device, which acquires images of the jets from the multiple spinning needles of one of the spinning units to obtain jet images, wherein the jets generated by the spinning needles include: straight jets and Taylor cone jets; and a control device, which is signal-connected to the image acquisition device and executes the following control instructions: Step C, for each of the M spinning needles extending from the spinning unit, the length of its straight jet is obtained from the jet image, and it is determined whether it is blocked based on its straight jet length, M≥2. This invention introduces computer software to judge the blockage of the spinning needles, replacing manual labor and reducing the time-consuming manual inspection of spinning needles required by current technology, thus preventing misjudgments by workers that could affect the quality of nanofiber membranes due to a lack of real-time monitoring.

Description

Technical Field

[0001] This invention relates to intelligent processing equipment in the high-end equipment manufacturing industry, and new chemical fibers and functional textile materials in the new materials industry, and particularly to a real-time monitoring system for electrospinning equipment. Background Technology

[0002] The preparation of nanofiber materials through electrospinning has been one of the most important academic and technological activities in the field of materials science and technology worldwide in the past decade. Electrospinning, with its advantages of simple manufacturing equipment, low spinning cost, wide variety of spinnable materials, and controllable process, has become one of the main methods for effectively preparing nanofiber materials.

[0003] With the rapid development of electrospinning technology research, the research on electrospinning equipment has entered the stage of industrialization equipment research. Increasing the number of spinning needles is an important way to increase the yield of electrospinned nanofiber membranes. However, in actual production, due to uncontrollable factors such as temperature, humidity, electric field, and small diameter of spinning needles, a large number of spinning needles will inevitably become clogged, which will greatly reduce production efficiency and affect the uniformity of nanofiber membranes.

[0004] Currently, the inspection and judgment of the condition of electrospinning needles still relies on manual labor, which has the following drawbacks:

[0005] (1) The human resource investment is too high, requiring staff to spend a lot of time and resources to frequently carry out supervision.

[0006] (2) The efficiency is too low. The electrospinning equipment used in industrial production has tens of thousands of spinning needles. A round of inspection requires a lot of time.

[0007] (3) It is not real-time. Staff cannot check the blockage of thousands of spinning needles at the same time. There will be situations where the spinning needles that are checked first are not blocked and the Taylor cone is normal, but blockage occurs after a round of checks and is not detected.

[0008] (4) Unstable product quality: Different standards for judging the blockage of spinning needles by human judgment and untimely replacement of spinning needles can lead to an unstable number of spinning needles in normal use, which in turn affects product quality. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] The present invention aims to at least partially solve one of the above-mentioned technical problems.

[0011] (II) Technical Solution

[0012] This invention provides a real-time monitoring system for an electrospinning device. The electrospinning device includes: N spinning units, where N≥2; each spinning unit extends multiple spinning needles; the real-time monitoring system includes;

[0013] The image acquisition device acquires images of the jets from multiple spinning needles in one of the spinning units to obtain jet images. The jets generated by the spinning needles include: straight jets and Taylor cone jets.

[0014] The control device, connected to the image acquisition device, executes the following control commands:

[0015] Step C: For each of the M spinning needles extending from the spinning unit, obtain its straight jet length from the jet image, and determine whether it is blocked based on its straight jet length, M≥2.

[0016] In some embodiments of the present invention, in step C of the control command executed by the control device, for the m-th spinning needle among the M spinning needles, it is determined whether it is blocked based on the similarity T between the current jet length and the pre-stored jet length:

[0017]

[0018] Among them, S n,m,p S is the length of the straight jet obtained from the jet image of the m-th spinning needle of the n-th spinning unit. n,m,0 To store the length of the direct jet;

[0019] Where, if T > T th To determine if the spinning needle is normal; if T < T th or S n,m,p =0, indicating spinneret blockage, Tth is the similarity threshold; where n = 1, 2, ..., N; m = 1, 2, ..., M.

[0020] In some embodiments of the present invention, the pre-stored direct jet length S n,m,0 For: the length of the direct jet obtained from the first jet photograph; or, a preset specific value.

[0021] In some embodiments of the present invention, step C of the control instruction executed by the control device includes:

[0022] Sub-step C1: Convert the jet image to grayscale;

[0023] Sub-step C2 involves thresholding the grayscale jet image.

[0024] Sub-step C3: Use grayscale histogram to calculate the contour and filter by area condition to identify the jet contour corresponding to M spinning needles in the jet image.

[0025] Sub-step C4: Count and identify the number of spinning needles, and number each jet profile.

[0026] Sub-step C5: For each of the M spinning needles, calculate the similarity T between the current straight jet length and the pre-stored straight jet length.

[0027] In sub-step C6, if T > Tth, the spinning needle is considered normal; if T < Tth, the spinning needle is considered normal. th or S n,m,p =0, indicating that the spinning needle is blocked;

[0028] Where Tth is the similarity threshold, satisfying: 60% ≤ T th <100%.

[0029] In some embodiments of the present invention, the device further includes: a motion device that carries the image acquisition device and drives the image acquisition device to move along a path perpendicular to the direction of the spinning unit; the motion device is an electric linear slide or a robotic arm that provides a motion path perpendicular to the direction of the spinning unit; and a control device that is signal-connected to the motion device, wherein the control command executed by the control device includes, before step C:

[0030] Step A: Move the motion device to the nth camera position corresponding to the nth spinning unit;

[0031] Step B: The image acquisition device acquires images of the jet generated by the M spinning needles extending from the nth spinning unit, and obtains jet images of the M spinning needles.

[0032] Where n = 1, 2, ..., N.

[0033] In some embodiments of the present invention, the optical axis of the image acquisition device is horizontal, and its height is between the spinning needle outlet and the bottom of the jet; the angle between it and the spinning unit being photographed is between 15° and 25°.

[0034] In some embodiments of the present invention, the optical axis of the image acquisition device is: its height is flush with the exit of the spinning needle; and the angle between it and the spinning unit being photographed is 20°.

[0035] In some embodiments of the present invention, the distance between adjacent spinning units is d; the initial position of the image acquisition device is located at a distance d in front of the first spinning unit; within one cycle, the motion device drives the image acquisition device to make uniform linear motion at a speed of v; the exposure time of the image acquisition device is set to d / v; the total stroke of the image acquisition device is d×(2N-1).

[0036] In some embodiments of the present invention, the number of spinning needles extending from the spinning unit is between 80 and 100.

[0037] In some embodiments of the present invention, the spacing between adjacent spinning units is between 25 and 45 cm.

[0038] In some embodiments of the present invention, the image acquisition device is a high-speed camera or an industrial camera.

[0039] In some embodiments of the present invention, the control instructions executed by the control device further include, after step C: step D, recording and displaying the state of the m-th spinning needle of the n-th spinning unit in the electrospinning equipment, where n = 1, 2, ..., N; m = 1, 2, ..., M; wherein different states are displayed in mutually distinct ways.

[0040] In some embodiments of the present invention, the control instructions executed by the control device further include, after step C: step E1, for the nth spinning unit, calculating the proportion of blocked spinning needles to the total number of spinning needles, and triggering a first alarm signal when the proportion exceeds a first blocking threshold.

[0041] In some embodiments of the present invention, the control instructions executed by the control device further include, after step C: step E2, for all N spinning units, calculating the proportion of blocked spinning needles to the total number of spinning needles, and triggering a second alarm signal when the proportion exceeds a second blocking threshold.

[0042] In some embodiments of the present invention, the control command executed by the control device further includes, after step C: step F, receiving an instruction to change the state of a certain spindle or a group of spindle needles, and changing the state of the corresponding spindle needle, including:

[0043] A command to change the state of a certain spinning needle will reset the state of that spinning needle; or

[0044] The reset command after replacing a spinning unit resets the state of the corresponding spinning needle in that spinning unit; or,

[0045] The reset command after replacing N spinning units resets the state of the corresponding spinning needles of the N spinning units.

[0046] (III) Beneficial Effects

[0047] As can be seen from the above technical solution, the present invention has at least one of the following beneficial effects compared to the prior art:

[0048] (1) The process of recording, comparing and analyzing images introduces computer software to judge the clogging of spinning needles. While replacing manual labor, the computer software judgment has better accuracy and timeliness, reducing the time-consuming manual inspection of spinning needles required by current technology, and preventing workers from making misjudgments that affect the quality of nanofiber membranes due to non-real-time issues.

[0049] (2) Experiments have shown that the present invention uses the length of the direct jet to determine whether the spinning needle is blocked. Compared with the Taylor cone area to reflect the electrospinning state, the accuracy of the identification is higher, the algorithm is simpler, and it can better meet the needs of real-time monitoring.

[0050] (3) In actual scenarios, due to the nature of the spinning needles themselves, the length of the straight jet produced by different spinning needles will also vary.

[0051] In this invention, the similarity T between the current direct jet length and the pre-stored direct jet length is used to determine whether it is blocked, which is more suitable for the needs of actual scenarios. Experiments have shown that the recognition accuracy is higher.

[0052] (4) By combining motion devices and image acquisition devices, and combining image processing and logic judgment of control devices, the blockage of spinning needles in electrospinning equipment can be monitored in a timely manner, and workers can react in a timely manner. This greatly reduces the loss of nanofiber membranes caused by spinning needle blockage, reduces equipment failure rate, reduces the number of downtimes, improves the quality and output of electrospinning, and enhances the production efficiency of enterprises.

[0053] (5) By moving the image acquisition device back and forth through the motion device to take pictures, it is possible to monitor the working status of all spinning needles, with comprehensive coverage and no blind spots, greatly improving the comprehensiveness of monitoring.

[0054] (6) Experiments have shown that the optical axis of the image acquisition device is horizontal, and its height is between the front end of the spinning needle and the bottom end of the jet; the angle between it and the spinning unit being photographed is between 15° and 25°, which can obtain a clearer and more accurate shooting effect, reduce the difficulty of image processing of the subsequent control device, and improve the recognition accuracy.

[0055] (7) The distance between adjacent spinning units is d; the motion device drives the image acquisition device to make uniform linear motion at a speed of v; the exposure time of the image acquisition device is set to d / v. By determining the motion path, speed of the motion device and the exposure time of the image acquisition device, the monitoring efficiency can be greatly improved, and real-time monitoring can be achieved.

[0056] (8) The image acquisition and control device realizes a semi-automated management process for the clogging of spinning needles in the industrial production of electrospinning, which involves "taking pictures, recording and comparing, counting and statistics, and control and feedback". In current solutions, these tasks need to be completed manually one by one. It can be seen that the present invention significantly reduces the working time of workers and saves human resources.

[0057] (9) A display page is provided to provide workers with real-time information on spinning needle blockage, down to each individual spinning needle. When a blockage occurs, workers can find the blocked spinning needle in time by its number and check it. Compared with the existing technology that requires checking each needle one by one, this invention is more accurate and convenient.

[0058] (10) It provides two blocking alarm modes and the function of changing the status of spinning needles, making it easier for operators to monitor the status and replace the spinning unit. Attached Figure Description

[0059] Figure 1 and Figure 2 These are, respectively, a perspective view and a top view of the real-time monitoring system for electrospinning equipment according to an embodiment of the present invention.

[0060] Figure 3 This is a schematic diagram of the spinning unit and spinning needle of the electrospinning equipment in an embodiment of the present invention.

[0061] Figure 4 This is a flowchart illustrating the operation of the electrospinning equipment according to an embodiment of the present invention.

[0062] Figure 5 This is a flowchart of the steps performed by the control device in the real-time monitoring system of the electrospinning equipment according to an embodiment of the present invention.

[0063] Figure 6 This is a schematic diagram of the jet ejected from the spinning needle in an embodiment of the present invention.

[0064] Figure 7 This is a screenshot of the control device display page in the real-time monitoring system of the electrospinning equipment according to an embodiment of the present invention. Detailed Implementation

[0065] This invention utilizes a combination of motion devices and image acquisition devices, along with image processing and logical judgment from a control device, to monitor the blockage of spinning needles in electrospinning equipment. This allows for timely detection of spinning needle blockages, enabling workers to react promptly and reducing losses of nanofiber membranes caused by spinning needle blockages, thereby improving enterprise production efficiency.

[0066] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0067] In one exemplary embodiment of the present invention, a real-time monitoring system for an electrospinning device is provided. Figure 1 and Figure 2 These are, respectively, a perspective view and a top view of the real-time monitoring system for electrospinning equipment according to an embodiment of the present invention.

[0068] Please refer to Figure 1 and Figure 2The electrospinning equipment includes: a liquid supply pipe 91, and N spinning units 92 connected to the liquid supply pipe, where N ≥ 2; each spinning unit extends multiple spinning needles 93. The spinning solution in the liquid supply pipe 91 flows into the spinning unit 92. The spinning unit 92 is used to supply the spinning solution to the spinning needles 93.

[0069] Please refer to Figure 1 and Figure 2 The real-time monitoring system for electrospinning equipment in this embodiment includes:

[0070] Motion device 10 provides a motion path perpendicular to the direction of the spinning unit;

[0071] The image acquisition device 20 can move along a path perpendicular to the direction of the spinning unit under the drive of the motion device;

[0072] Each spinning unit corresponds to a camera position. The image acquisition device is driven to the camera position by the motion device to acquire images of the jet from the multiple spinning needles of the spinning unit and obtain jet images.

[0073] The control device, with signals connected to the motion device and the image acquisition device, is used to determine the blockage status of multiple spinning needles in the spinning unit based on the jet image.

[0074] It should be noted that this invention has two independent innovative aspects. Specifically:

[0075] First, dynamic camera

[0076] The motion device drives the image acquisition device to move back and forth to perform dynamic video recording, thereby monitoring the working status of all spinning needles, providing comprehensive coverage without blind spots, and greatly improving the overall monitoring capabilities.

[0077] Second, blockage is determined by the similarity of the direct jet stream.

[0078] By using the length of the direct jet, preferably the similarity between the current direct jet length and the pre-stored direct jet length, it is possible to determine whether the spinning needle is blocked. Compared with identifying the Taylor cone area to reflect the electrospinning state, the identification accuracy is higher, the algorithm is simpler, and it can better meet the needs of real-time monitoring.

[0079] The two innovations mentioned above are independent and can be implemented and applied independently. The technical features for realizing these two innovations are also different. Those skilled in the art should be able to determine the technical features required for independently implementing and applying a particular innovation based on the following description and their own professional knowledge. These will be explained together in this document.

[0080] The following is a detailed description of each component of the real-time monitoring system for the electrospinning equipment in this embodiment.

[0081] In this invention, there is no limitation on the number of spinning units included in the electrospinning equipment, or the number of spinning needles in each spinning unit. In other words, this invention is applicable to any electrospinning equipment that includes two or more spinning units, each of which includes two or more spinning needles.

[0082] Figure 3 This is a schematic diagram of the spinning unit and spinning needles of the electrospinning equipment in an embodiment of the present invention. Figure 1 and Figure 3 As shown, the spacing between adjacent spinning units is 30cm. The leftmost spinning unit is numbered Spinning Unit 1, and so on to the right. Spinning needle 93 is a linear spinning needle, oriented vertically downwards, with a needle length of 3cm, a needle spacing of 1cm, and 80-100 spinning needles per spinning unit, with a needle hole diameter of 0.6mm. The innermost spinning needle is numbered Spinning Needle 1, and so on outwards.

[0083] The motion device 10, specifically an electric linear slide, is used to move the image acquisition device 20. The electric linear slide is 300cm long and its height is the same as the height of the spinning needle. During movement, the slide carries the image acquisition device and causes it to move periodically at a speed of 30cm / s, with the direction of movement perpendicular to the direction of the spinning unit, and the cycle time is 15s / T. Of course, the movement speed, cycle time, and other parameters of the slide are related to the spacing of the spinning units and the acquisition frequency of the image acquisition device, which will be explained in detail below.

[0084] Those skilled in the art should understand that an electric linear slide can also be replaced by a robotic arm, as long as it can support the image acquisition device and make it move along a predetermined trajectory and speed.

[0085] The image acquisition device, specifically a high-speed camera, is used to capture the Taylor cone shape beneath the spinning needle, particularly the straight-flow portion. For example... Figure 2 As shown, the high-speed camera is fixed on the electric linear slide, with its initial position 30cm to the left of spinning unit 1, and the distance between the lens and the spinning unit is 20cm.

[0086] Those skilled in the art should understand that high-speed cameras can also be replaced by industrial cameras, as long as they can be fixed on the motion mechanism and take pictures of the spinning needles below the spinning unit at a preset frequency and resolution.

[0087] Regarding the motion device and image acquisition device, the following three points need special explanation:

[0088] 1. Optical axis of the image acquisition device

[0089] Unlike existing technologies that observe Taylor cone jets, this invention observes the direct jet and uses this observation to determine the blockage status of the spinning needle. Therefore, in this invention, the optical axis of the image acquisition device should be aligned as closely as possible with the position of the direct jet. Specifically, the optical axis of the image acquisition device is horizontal, and its height is between the spinning needle outlet and the bottom of the jet. Preferably, the height of the optical axis of the image acquisition device is flush with the spinning needle outlet.

[0090] 2. Tilting angle of the image acquisition device

[0091] Because the spinning needles on the spinning unit are arranged in rows and are very densely packed, the image acquisition device must be tilted to capture a clear, unobstructed image of the spinning needles. It is important to note that the tilt angle will affect the horizontal distance between the camera and spinning unit number 1.

[0092] After numerous simulation experiments, the tilt angle α between the optical axis of the image acquisition device and the extension direction of the spinning unit can realize the present invention in the range of 15°-25°, with a tilt angle of 20° being the optimal value.

[0093] 3. Movement speed of the image acquisition device

[0094] In this invention, the image acquisition device acquires images of the jet flow from multiple spinning needles on the spinning unit, which can be achieved through the following two methods:

[0095] (1) Pause-style photography

[0096] The motion device moves the image acquisition device to a preset position, stops, and takes a picture of the jet flow of the corresponding spinning needle in the spinning unit; then it continues to move to the next preset position, stops, and takes a picture of the jet flow of the next spinning needle in the next spinning unit.

[0097] This method can achieve the present invention. Its advantage is that it has low hardware requirements for motion devices and image acquisition devices and good image quality, but its disadvantage is that it wastes time and has poor real-time monitoring effect.

[0098] (2) Continuous photography

[0099] Within one cycle, the motion device drives the image acquisition device to move continuously, taking pictures during the movement. Within one cycle, the image acquisition device moves from spinning unit 1 to spinning unit N, and then returns. In this case, the speed of the motion device and the exposure speed of the image acquisition device need to be designed in conjunction with the spacing between the spinning units.

[0100] like Figure 2As shown, in this embodiment, the length of the spinning unit is 160cm-180cm, the diameter D is 3-5cm, the spacing d1 between adjacent spinning units is 30cm, the horizontal distance d2 between the center of the high-speed camera lens and the spinning unit is 30cm, the horizontal distance d3 between the spinning unit and the slide table is 20cm, and the camera focus position is approximately 100cm from the camera's vertical distance d4, close to the center of the spinning unit being photographed.

[0101] Please continue to refer to Figure 2 The distance between adjacent spinning units is d = d1 + D; the motion device drives the image acquisition device to move in uniform linear motion at a speed of v; the exposure time of the image acquisition device is set to d / v; the initial position of the image acquisition device is located at a distance d in front of the first spinning unit; the total stroke of the image acquisition device in one cycle is d × (2N-1).

[0102] Specifically, in this embodiment, the spacing between the spinning units is 30cm, and the camera movement speed is 30cm / s. Therefore, the camera exposure speed is set to 1 time / s. So the initial position is preferably 30cm to the left of the No. 1 spinning unit. The total stroke of the image acquisition device is d×(2N-1). With the above settings, it is convenient to form a regular periodic motion.

[0103] In this invention, a control device signal is connected to the motion device and the image acquisition device to determine the blockage status of multiple spinning needles in the spinning unit based on the jet image. Specifically, the jet length is obtained from the jet image, and the similarity between the current jet length and the pre-stored jet length is analyzed to determine whether each spinning needle is blocked.

[0104] In real-world scenarios, the control device achieves the functions of storing, comparing, and analyzing images, displaying the status of spinning needle blockage, and issuing alarms through the following steps.

[0105] Figure 4 This is a flowchart illustrating the operation of the electrospinning equipment according to an embodiment of the present invention. Figure 5 This is a flowchart illustrating the steps performed by the control device in the real-time monitoring system of the electrospinning equipment according to an embodiment of the present invention. Please refer to... Figure 4 and Figure 5 In this embodiment, the steps performed by the control device include:

[0106] Initialization: Data format normalization

[0107] The control device pre-standardizes the data format of the spinning needle, jet image, and spinning needle status: (ab) p-c, where a is the spinning unit number, b is the spinning needle number, p is the image number, and c is the status number. The status number c can be either 0 or 1: 0 indicates the spinning needle is not blocked; 1 indicates the spinning needle is blocked. (ab) p -c refers to the image obtained from the pth photograph of needle b in spinning unit a, and the state of the spinning needle at this time.

[0108] Step A: Move the motion device to the nth camera position corresponding to the nth spinning unit;

[0109] In this embodiment, the electric linear slide moves at a preset speed under the control of the control device. It stops at a preset position and returns to start the next cycle.

[0110] Step B: The image acquisition device takes pictures of the jet generated by the M spinning needles extending from the nth spinning unit to obtain the jet image of the M spinning needles, where M≥2.

[0111] In this embodiment, the high-speed camera can take pictures of the jet of M spinning needles during the movement and transmit the jet image to the control device.

[0112] Step C: For the m-th spinning needle among the M spinning needles, determine whether it is blocked according to its jetting condition, where m = 1, 2, ..., M;

[0113] Step C further includes:

[0114] Sub-step C1: Convert the jet image to grayscale;

[0115] Sub-step C2 involves thresholding the grayscale jet image.

[0116] Sub-step C3: Image feature description and target analysis;

[0117] The contours were calculated using grayscale histograms and filtered by area criteria to identify the jet contours corresponding to M spinning needles in the jet image.

[0118] Sub-step C4: Count and identify the number of spinning needles, and number each jet profile;

[0119] Sub-step C5: For each of the M spinning needles, calculate the similarity T between the length of the current straight jet and the first (or pre-stored) straight jet.

[0120] Figure 6 This is a schematic diagram of the jet ejected from the spinning needle in an embodiment of the present invention. As shown in the figure, in a real-world scenario, the spinning solution 94 in the spinning needle 93 forms nanofibers downwards under the influence of an electrostatic field, and its jet can be divided into two parts: a direct jet JF. D and Taylor cone jet JFT .

[0121] Through experiments, the inventors discovered that since the blocked spinning needles do not produce Taylor cones or straight jets during electrospinning, the electrospinning state can be reflected by comparing the changes in the length of the straight jets (similarity) between two photos taken before and after the process.

[0122] In this invention, a high-speed camera captures images of the spinning needle and its direct jet, uploading the images to a control device. The control device distinguishes between the direct jet and the Taylor cone jet in the images, thereby obtaining the length of the direct jet. If the similarity T between the current direct jet length and the pre-stored direct jet length is greater than T... th If the electrospinning state is normal, it is considered that the electrospinning needle is not blocked and the spinning is normal; otherwise, it is considered that the electrospinning state has changed significantly and the spinning needle is blocked.

[0123] Specifically, for each of the M spinning needles, its blockage is determined based on the similarity T between the current jet length and the pre-stored jet length:

[0124]

[0125] Among them, S n,m,p For the m-th spinning needle of the n-th spinning unit, based on the jet pattern of this (p-th) jet, i.e. (ab) p The obtained direct jet length is S. n,m,0 The first jet image taken after the new spinning needles were installed, i.e. (ab)1, shows the length of the straight jet.

[0126] It should be noted that, in this embodiment, S n,m,0 The jet image taken after the new spinning needle is installed is (ab)1, which is the length of the straight jet. However, in other embodiments of the present invention, a specific value can be preset by those skilled in the art based on experience, instead of taking a separate picture and calculating for a certain spinning needle, which can greatly improve the calculation speed.

[0127] Sub-step C6, if T > T th To determine if the spinning needle is normal; if T < T th or S n,m,p =0, indicating that the spinning needle is blocked;

[0128] Among them, T th This is the similarity threshold. In this embodiment, T is... th =80%. In other embodiments of the invention, T th Values ​​greater than 60% and less than 100% are acceptable.

[0129] In this embodiment, all Taylor cone morphology photographs of spinning needles are compared in the manner described above, and the similarity is calculated. If the similarity between two photographs is ≥80%, the spinning needle is considered not to be blocked, and the spinning needle is marked as (ab). p -1, if the similarity between the two photos is <80% or S n,m,p When the value is 0, the spinning needle is considered blocked, and the spinning needle is marked as (ab). p -0.

[0130] In this embodiment, determining the clogging status of the spinning needle based on the similarity of the direct jet has the following advantages:

[0131] (1) Using the similarity of the length of the direct jet is more accurate.

[0132] Taylor cones may become unstable due to various reasons during production, leading to misjudgments when calculating area similarity.

[0133] Compared to Taylor cone jet JF T Direct jet JF D The change in the length of the direct jet before and after the spinning needle is blocked is very obvious, making it easier to identify and measure, thus making the similarity calculation more accurate and the judgment of the blockage more precise.

[0134] (2) The design is simpler when using the direct jet similarity algorithm.

[0135] Calculating the area of ​​a Taylor cone jet requires multiple geometric parameters. Extracting these parameters is time-consuming, and calculating the area itself is even more time-consuming, failing to meet the needs of real-time monitoring. However, the method of this invention for calculating the direct jet length is simpler and more efficient than calculating the Taylor cone area. Experiments have shown that the accuracy of this invention can reach or even exceed that of methods for calculating blockages using the Taylor cone jet area.

[0136] Subsequently, steps A through C are repeated to obtain the blockage status of all spinning needles in all spinning units.

[0137] Step D: Record and display the state of the m-th spinning needle in the n-th spinning unit of the electrospinning equipment, where n = 1, 2, ..., N; m = 1, 2, ..., M; and different states are displayed in a way that distinguishes them from each other.

[0138] Figure 7 This is a screenshot of the control device display page in the real-time monitoring system of the electrospinning equipment according to an embodiment of the present invention. The screenshot visually displays the status of each spinning needle in each spinning unit. (In standard data format (ab)) pIn the -c option, c represents the status number. The status number c can be either 0 or 1: 0 indicates that the spinning needle is not clogged, and it is displayed in green on the screen (or gray in a grayscale image); 1 indicates that the spinning needle is clogged, and it is displayed in red on the screen (or black in a grayscale image).

[0139] In this embodiment, the control device provides a display page that can provide workers with real-time information on spinning needle blockage, down to each individual needle. When a blockage occurs, workers can quickly locate and inspect the blocked spinning needle based on its number. Compared to the existing technology that requires inspecting each needle individually, this method is simpler and more effective, significantly improving work efficiency and saving workload and labor costs.

[0140] Step E, Blocking Alarm

[0141] In this embodiment, two types of alarms are provided: the first is an alarm indicating a large amount of spinning needle blockage in a certain spinning unit; the second is an alarm indicating a large amount of spinning needle blockage in all spinning units. In practical scenarios, those skilled in the art can choose one or both.

[0142] 1. Single spinning unit

[0143] In sub-step E1, for the nth spinning unit, the proportion of blocked spinning needles to the total number of spinning needles is calculated. When the proportion exceeds a first blocking threshold, a first alarm signal is triggered. Generally, this first blocking threshold is set to a value between 5% and 40%.

[0144] 2. All spinning units

[0145] In sub-step E2, for all N spinning units, the proportion of blocked spinning needles to the total number of spinning needles is calculated. When this proportion exceeds a second blocking threshold, an alarm signal is triggered. Typically, this second blocking threshold is set between 5% and 40%.

[0146] Step F, Changes and adjustments to the blocking state

[0147] Receive instructions to change the state of one or more spinning needles, and change the state of the corresponding spinning needles. The instruction to change a group of spinning needles is as follows:

[0148] ① A command to change the state of a certain spinning needle. At this time, the state of the spinning needle is reset.

[0149] ② Reset command after replacing a certain spinning unit. At this time, the state of the corresponding spinning needle of the spinning unit is reset.

[0150] ③ Reset command after replacing N spinning units. At this time, the state of the corresponding spinning needles of the N spinning units is reset.

[0151] Specifically, workers can manually turn off the horn sound on the control device page to indicate that an alarm signal has been received. For spinning needles that are blocked but do not need to be replaced, workers can reset the status number "c" from 1 to 0 on the control device page, and the corresponding spinning needle color will change from red to green. The change in the number will then be reported back to the alarm circuit.

[0152] Whenever a spinning needle's number is changed, the system calculates the ratio of the spinning needle numbered 1 to the total number of spinning needles. When this ratio is greater than 30%, an alarm is triggered, alerting the worker to come and check. If the machine is stopped to replace the needle, the alarm system is reset, and the status number of all spinning needles is renumbered to 0. If the machine is not stopped to replace the needle, the alarm system will receive feedback from the worker regarding the number change and change the status number 'c' of the blocked but not changed spinning needle to 0.

[0153] Repeat steps E and F until no more alarms are triggered.

[0154] As can be seen, the present invention provides two blocking alarm modes and the function of changing the state of the spinning needle, making it more convenient for operators to monitor the state and replace the spinning unit.

[0155] In summary, this invention provides a semi-automated management process for managing spinning needle blockage during industrial electrospinning production, involving "taking photos, recording and comparing data, counting and statistics, and control and feedback." Current solutions require workers to complete these tasks step-by-step; this invention significantly reduces worker time and saves human resources.

[0156] Furthermore, in this invention, the process of recording, comparing, and analyzing jet images incorporates computer software to determine the clogging status of the spinning needles. This replaces manual labor, and the computer-based judgment offers better accuracy and timeliness, reducing the time-consuming manual inspection of spinning needles required by current technology and preventing misjudgments by workers that could affect the quality of the nanofiber membrane.

[0157] This concludes the description of the various embodiments of the present invention. Based on the above description, those skilled in the art should have a clear understanding of the present invention.

[0158] It should be noted that, unless explicitly stated otherwise, the numerical parameters in the specification and claims of this invention may be approximate values ​​and can be changed according to the content of this invention. Specifically, all figures in the specification and claims indicating the content of composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases, which means that they include a specific quantity varying by ±10% in some embodiments.

[0159] Furthermore, unless otherwise specified or required to occur in sequence, the order of the above steps is not limited to those listed above and may be varied or rearranged as needed for the design.

[0160] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," "right," "inner," and "outer," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of the present invention. Throughout the accompanying drawings, the same elements are represented by the same or similar reference numerals. Furthermore, the shapes and dimensions of the components in the drawings do not reflect their actual size and proportions, but are only intended to illustrate the content of the embodiments of the present invention.

[0161] Those skilled in the art will understand that in the claims and specification of this invention, the word "comprising" does not exclude the presence of elements (or steps) not listed in the claims. The word "a" or "an" preceding an element (or step) does not exclude the presence of a plurality of such elements (or steps).

[0162] For certain implementations, if they are not key aspects of the present invention and are well-known to those skilled in the art, they have not been described in detail in the accompanying drawings or text due to space limitations. In such cases, reference can be made to relevant prior art for understanding. Furthermore, the purpose of providing the above embodiments is merely to ensure that the present invention meets legal requirements. The present invention can be implemented in many different forms and should not be construed as limited to the embodiments described herein. Moreover, the above definitions of elements and methods are not limited to the various specific structures, shapes, or methods mentioned in the embodiments, and those skilled in the art can make simple modifications or substitutions.

[0163] Similarly, it should be understood that, for the sake of brevity, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of invention should not be construed as reflecting an intention that the claimed invention requires more features than expressly recited in each claim. Rather, as reflected in the claims, the various inventive aspects consist of fewer than all the features of the preceding single embodiment. Furthermore, embodiments may be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.

[0164] The above specific embodiments have provided a detailed description of the purpose, technical means, and beneficial effects of the present invention. It should be understood that the purpose of the detailed description is to enable those skilled in the art to better understand the present invention, and it is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A real-time monitoring system for electrospinning equipment, characterized in that, The electrospinning equipment includes: N spinning units, where N≥2; each spinning unit extends multiple spinning needles; The real-time monitoring system includes: The image acquisition device acquires images of the jets from multiple spinning needles in one of the spinning units to obtain jet images. The jets generated by the spinning needles include: straight jets and Taylor cone jets. A motion device that carries the image acquisition device and drives the image acquisition device to move along a path perpendicular to the direction of the spinning unit; wherein the motion device is an electric linear slide or a robotic arm that provides a motion path perpendicular to the direction of the spinning unit. The control device, connected to the image acquisition device and the motion device, executes the following control commands: Step A: The motion device moves the image acquisition device to the nth camera position corresponding to the nth spinning unit; the distance between adjacent spinning units is d; the initial position of the image acquisition device is located at a distance d in front of the first spinning unit; within one cycle, the motion device moves the image acquisition device in uniform linear motion at a speed of v; the exposure time of the image acquisition device is set to d / v; the total stroke of the image acquisition device is d×(2N-1). Step B: The image acquisition device acquires images of the jet generated by the M spinning needles extending from the nth spinning unit, and obtains jet images of the M spinning needles; where n = 1, 2, ..., N. Step C: For each of the M spinning needles extending from the spinning unit, obtain its straight jet length from the jet image, and determine whether it is blocked according to its straight jet length, M≥2; In step C of the control command executed by the control device, for the m-th spinning needle among the M spinning needles, it is determined whether it is blocked based on the similarity T between the current jet length and the pre-stored jet length: in, The length of the straight jet obtained from the jet image of the m-th spinning needle in the n-th spinning unit. To store the length of the direct jet; Where, if T > T th To determine if the spinning needle is normal; if T < T th or S n,m,p =0, indicating spinneret blockage, T th The similarity threshold; Where n = 1, 2, ..., N; m = 1, 2, ..., M; The pre-stored direct jet length The length of the direct jet obtained from the first jet image is: or, a preset specific value; Step C of the control command executed by the control device includes: Sub-step C1, performing grayscale processing on the jet image; Sub-step C2, performing threshold segmentation on the grayscale processed jet image; Sub-step C3, calculating the contour using a grayscale histogram and filtering by area condition to identify the jet contour corresponding to M spinning needles in the jet image; Sub-step C4, counting and identifying the number of spinning needles and numbering each jet contour; Sub-step C5, for each of the M spinning needles, calculating the similarity T between the current direct jet length and the pre-stored direct jet length; Sub-step C6, if T > T th To determine if the spinning needle is normal; if T < T th or S n,m,p =0, indicating spinneret blockage; where, T th The similarity threshold satisfies: 60% ≤ T th <100%.

2. The real-time monitoring system according to claim 1, characterized in that, The optical axis of the image acquisition device is horizontal, and its height is between the spinning needle outlet and the bottom of the jet; the angle between it and the spinning unit being photographed is between 15° and 25°.

3. The real-time monitoring system according to claim 2, characterized in that, The optical axis of the image acquisition device is at the same height as the exit of the spinning needle, and the angle between it and the spinning unit being photographed is 20°.

4. The real-time monitoring system according to claim 1, characterized in that: The number of spinning needles extending from the spinning unit is between 80 and 100; and / or The spacing between adjacent spinning units is between 25 and 45 cm; and / or The image acquisition device is a high-speed camera or an industrial camera.

5. The real-time monitoring system according to any one of claims 1 to 4, characterized in that, The control commands executed by the control device further include, after step C: Step D: Record and display the state of the m-th spinning needle in the n-th spinning unit of the electrospinning equipment, where n = 1, 2, ..., N; m = 1, 2, ..., M; and different states are displayed using distinct display methods; and / or Step E1: For the nth spinning unit, calculate the proportion of blocked spinning needles to the total number of spinning needles. When the proportion exceeds the first blocking threshold, trigger the first alarm signal; and / or Step E2: For all N spinning units, calculate the proportion of blocked spinning needles to the total number of spinning needles. When this proportion exceeds the second blocking threshold, trigger the second alarm signal; and / or Step F: Receive an instruction to change the state of a single spinning needle or a group of spinning needles, and change the state of the corresponding spinning needle, including: A command to change the state of a certain spinning needle will reset the state of that spinning needle; or The reset command after replacing a spinning unit resets the state of the corresponding spinning needle in that spinning unit; or, The reset command after replacing N spinning units resets the state of the corresponding spinning needles of the N spinning units.

Images