Dispensing valve adjusting method with self-adaptive pressure feedback

Abstract

The invention provides a self-adaptive pressure feedback glue dispensing valve adjusting method which comprises the following steps: in a glue drop spraying process, continuously shooting a plurality of first images, and shooting a second image after the glue drops drop. Obtaining the track of the glue drop according to the plurality of first images, and calculating a first included angle between the track of the glue drop and the vertical direction; and correcting the area of the glue drop in the second image through the first included angle so as to calculate the actual first volume of the glue drop. And finally, according to the first volume and the preset volume of the glue drops, adjusting the pressure when the dispensing valve sprays the glue drops. According to the scheme, the included angle between the track and the vertical direction in the glue drop spraying process can be automatically recognized, and then the calculation process of the glue drop volume is corrected; therefore, the pressure when the dispensing valve sprays the glue drops is adjusted, and the volume of the sprayed glue drops can be ensured to be consistent.

Description

Technical Field

[0001] This invention generally relates to the field of dispensing valve technology, and more specifically to an adaptive pressure feedback dispensing valve adjustment method. Background Technology

[0002] In the prior art, the dispensing pressure of the needle-type dispensing valve is usually set by an independent pressure controller and remains constant during the dispensing process or is adjusted in stages according to a preset program.

[0003] However, in actual production, the viscosity of the adhesive will dynamically change with factors such as ambient temperature, its own aging, and solvent evaporation. The nozzle may also experience slight wear or blockage due to residual adhesive. These factors will all cause an angle between the actual trajectory of the adhesive droplets and the preset trajectory when the droplets are sprayed.

[0004] Furthermore, existing systems lack real-time monitoring capabilities for spraying results, failing to detect the impact of defects such as uneven glue dot size, inconsistent glue line thickness, stringing, and oblique spraying on the volume of sprayed glue droplets. Operators often need to identify defective products through offline inspection after dispensing and then manually adjust parameters. This not only leads to material waste and low production efficiency but also makes it difficult to achieve truly fully automated precision production. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide an adaptive pressure feedback method for dispensing valve adjustment.

[0006] This invention provides an adaptive pressure feedback method for adjusting a dispensing valve, comprising: S1: Continuously capture multiple first images during the process of the dispensing valve spraying adhesive droplets; the shooting directions of the multiple first images include two mutually perpendicular horizontal directions; S2: Capture a second image of the dripping glue droplets; the second image is captured vertically. S3: Based on multiple images of the first image, calculate the first angle between the straight trajectory of the droplet and the vertical direction; S4: Calculate the first volume of the droplet based on the first included angle and the second image; S5: Adjust the pressure of the dispensing valve when spraying the glue droplets based on the first volume and the preset volume of the glue droplets.

[0007] According to the technical solution provided by the present invention, the step of calculating the first angle between the straight trajectory of the glue droplet and the vertical direction based on multiple first images includes: Multiple first images are superimposed to form a third image; the third image contains the positions of the droplets in the pixel coordinate system of all the first images; Edge detection is performed on the third image to obtain a set of contour pixels at multiple locations where the droplets are located; Calculate the centroid of each contour pixel set to obtain multiple centroid coordinates; Based on multiple centroid coordinates, the linear trajectory of the droplet during the spraying process is fitted; Obtain the vertical trajectory corresponding to the vertical direction; Calculate the angle between the vertical trajectory and the straight trajectory to obtain the first included angle.

[0008] According to the technical solution provided by the present invention, calculating the first volume of the droplet based on the first included angle and the second image includes: S4-1: Identify the total number of first pixels of the glue droplets in the second image; S4-2: Based on the first included angle, the total number of the first pixel is corrected to obtain the total number of the second pixel; S4-3: Calculate the volume of the glue droplet based on the total number of the second pixels to obtain the first volume.

[0009] According to the technical solution provided by the present invention, the identification of the total number of first pixels of glue droplets in the second image includes: The second image is binarized, and edge detection is performed on the location of the droplet to obtain multiple contour pixels; the multiple contour pixels form a closed shape. The total number of pixels within the closed shape formed by the outline pixels is counted and added to the total number of outline pixels to obtain the first total number of pixels.

[0010] According to the technical solution provided by the present invention, the step of correcting the total number of first pixels based on the first included angle to obtain the total number of second pixels includes: Obtain the correction formula; the correction formula is used to calculate the vertical projection area based on the tilted projection area and the tilt angle. Substitute the first total number of pixels and the first included angle into the correction formula to calculate the second total number of pixels.

[0011] According to the technical solution provided by the present invention, the step of calculating the volume of the adhesive droplet based on the total number of the second pixels to obtain the first volume includes: Obtain preset calibration coefficients; the preset calibration coefficients are used to characterize the conversion relationship between the area and volume of the droplets in the image; The first volume is calculated based on the preset calibration coefficient and the total number of second pixels.

[0012] According to the technical solution provided by the present invention, adjusting the pressure of the dispensing valve when spraying the adhesive droplet based on the first volume and the preset volume of the adhesive droplet includes: Calculate the difference between the preset volume and the first volume to obtain the volume deviation; Based on the volume deviation, calculate the pressure adjustment amount; Get the current dispensing valve pressure value; The corrected pressure value is calculated by adding the pressure adjustment amount to the current dispensing valve pressure value. Adjust the pressure of the dispensing valve to spray adhesive droplets to the corrected pressure value.

[0013] The beneficial effects of this invention are as follows: During the dispensing of adhesive droplets, multiple first images are continuously captured, and a second image is captured after the droplet falls. The trajectory of the droplet is obtained from the multiple first images, and the first angle between the droplet trajectory and the vertical direction is calculated. The area of ​​the droplet in the second image is corrected using this first angle, thereby calculating the actual first volume of the droplet. Finally, based on the first volume and the preset volume of the droplet, the pressure of the dispensing valve is adjusted when dispensing the droplet. Following this method, the angle between the trajectory of the droplet and the vertical direction during dispensing can be automatically identified, thus correcting the calculation process of the droplet volume; adjusting the pressure of the dispensing valve during dispensing ensures that the volume of the dispensed droplet remains consistent throughout. Attached Figure Description

[0014] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart illustrating an adaptive pressure feedback method for adjusting a dispensing valve. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] refer to Figure 1 This invention provides an adaptive pressure feedback method for adjusting a dispensing valve, comprising: S1: Continuously capture multiple first images during the process of the dispensing valve spraying adhesive droplets; the shooting directions of the multiple first images include two mutually perpendicular horizontal directions.

[0018] Specifically, under normal circumstances, the dispensing valve sprays in a vertical direction, and the trajectory of the dispensing droplet is also a vertical straight line. If the viscosity of the adhesive changes dynamically with factors such as ambient temperature, its own aging, and solvent evaporation, or if the nozzle experiences slight wear or blockage due to residual adhesive, the direction of the dispensing droplet may not be parallel to the vertical direction.

[0019] In order to capture the complete trajectory of the droplet movement, a high-speed camera was used, and multiple first images were taken in a horizontal direction.

[0020] S2: Capture the second image of the dripping glue droplets; In this embodiment, in order to calculate the volume of the glue droplet, it is necessary to first identify the area where the glue droplet falls. To identify the area more accurately, the shooting direction needs to be perpendicular to the plane where the glue droplet falls, that is, the shooting direction of the second image is vertical.

[0021] Specifically, if the direction of tilt during the ejection of the adhesive droplets is parallel to the shooting direction of the first image, a single high-speed camera cannot capture the tilt angle. That is, as long as the tilt direction is not perpendicular to the shooting direction, the tilt angle of the adhesive droplets captured by the high-speed camera will be smaller than the actual tilt angle.

[0022] For the reasons mentioned above, in this embodiment, two high-speed cameras are selected to capture multiple first images in a completely synchronized manner from two mutually perpendicular shooting directions (so that the droplets in the two corresponding first images are at the same position in three-dimensional space); the multiple first images are divided into two groups according to the cameras used for shooting. Both sets of first images are processed according to steps S3-1 to S3-3, and the centroid coordinates are calculated (at this time, they are only coordinates in the pixel coordinate system), resulting in two sets of centroid coordinates. The x-coordinate of the pixel coordinates of one set of first images is used as the depth information in the pixel coordinates of another set of first images, and finally the centroid coordinates in three-dimensional space are calculated.

[0023] S3: Based on multiple images of the first image, calculate the first angle between the straight trajectory of the droplet and the vertical direction, including: In this embodiment, Gaussian filtering is first applied to multiple first images to suppress noise. The filter kernel size is 3×3 pixels, and the standard deviation is 0.5. Subsequently, a histogram equalization algorithm is used to enhance image contrast and improve the distinction between the droplets and the background.

[0024] S3-1: Superimpose multiple first images to form a third image; the third image contains the positions of all the droplets in the first images in the pixel coordinate system; Because the high-speed camera captures multiple first images continuously while remaining stationary throughout the process, the origins of the pixel coordinate systems in all the first images correspond to the same point in space, and the horizontal and vertical axes of the pixel coordinate systems in all the first images are collinear. The only difference between the multiple first images is the position of the droplets in the pixel coordinate system.

[0025] Based on the above, the process of superimposing multiple first images is as follows: the origins of the pixel coordinate systems in multiple first images taken by the same high-speed camera are made to coincide, the horizontal axes are made to coincide, and the vertical axes are made to coincide.

[0026] In this embodiment, multiple first images are superimposed to form a third image, which enables multiple positions of the glue droplet during its movement in space after it is ejected to appear simultaneously in one image.

[0027] In the subsequent edge detection process, the edges of the droplets at multiple locations can be identified at once, eliminating the need to perform edge detection on multiple first images separately, thus reducing computational complexity.

[0028] In some implementations, to avoid overlapping of multiple locations of the droplets in the superimposed third image, the time interval between two adjacent first images needs to be greater than a first set duration.

[0029] To prevent droplets from overlapping, the first set time T must be greater than the ratio of the maximum droplet diameter D to the average droplet velocity V during spraying, i.e., satisfying the following:

[0030] Wherein, the maximum diameter D of the glue droplet is the diameter of the largest volume of glue droplet that the dispensing valve can spray when it is in a spherical state.

[0031] The average velocity V of the glue droplet during the spraying process is equal to the ratio of the distance from the nozzle of the dispensing valve to the droplet's landing position (measured experimentally) to the time taken for the glue droplet to travel from spraying to landing (measured experimentally).

[0032] Based on the above method, the distance traveled by a droplet moving at a speed of V for a time T must be greater than the droplet's maximum diameter D. Therefore, in the resulting third image after superposition, adjacent droplets will not overlap. Thus, by performing edge detection and calculating the centroid, the coordinates of the centroid can be obtained relatively accurately.

[0033] S3-2: Perform edge detection on the third image to obtain the set of contour pixels at multiple locations where the droplets are located; Specifically, the Canny edge detection operator is used to identify the contours of the glue droplets at multiple locations in the third image, resulting in multiple contour pixel sets. Each contour pixel set contains the pixel coordinates of all the glue droplet contours at a given location.

[0034] S3-3: Calculate the centroid of each contour pixel set to obtain multiple centroid coordinates; The process of calculating the centroid includes: The horizontal axis coordinates of the centroid are obtained by averaging the horizontal coordinates of all pixels in this contour pixel set. The centroid's ordinate is obtained by averaging the ordinates of all pixels in this contour pixel set along their vertical axes.

[0035] The horizontal axis coordinate of the centroid and the vertical axis coordinate of the centroid together form the centroid coordinate system.

[0036] S3-4: Fit the linear trajectory of the droplet during the jetting process based on multiple centroid coordinates (coordinates in three-dimensional space); At this step, with the coordinates of multiple centroids known, the trajectory of the droplet can be fitted using the least squares method to obtain a straight-line trajectory.

[0037] S3-5: Obtain the vertical trajectory corresponding to the vertical direction; In this embodiment, the high-speed camera is set horizontally so that its shooting direction is horizontal. This setting makes the horizontal axis of the pixel coordinate system perpendicular to its shooting direction, and the vertical axis of the pixel coordinate system vertical.

[0038] Based on the previous text, the actual spray trajectory of the droplets has been transformed into a straight line trajectory in a three-dimensional coordinate system. If we want to calculate the angle between the straight line trajectory and the vertical direction, we need to transform the vertical direction into a vertical trajectory in a three-dimensional coordinate system.

[0039] In this embodiment, the dispensing valve is assumed to spray adhesive droplets in a vertical direction. Therefore, the vertical trajectory is pre-set manually and can be directly called during the actual calculation process.

[0040] S3-6: Calculate the angle between the vertical trajectory and the straight trajectory to obtain the first included angle.

[0041] Two angles are obtained by calculating the angle between the two straight lines. One is an acute angle, and the other is an obtuse angle. In reality, the direction of the sprayed adhesive droplets may only deviate slightly; therefore, the calculated acute angle is taken as the first angle.

[0042] Step S3 yields the true angle between the adhesive droplet and the vertical direction during spraying, ultimately making the adjustment of the dispensing valve pressure more accurate.

[0043] S4: Based on the first included angle and the second image, calculate the first volume of the droplet, including: S4-1: The total number of first pixels identifying the glue droplets in the second image includes: The second image is binarized, and edge detection is performed on the location of the droplet to obtain multiple contour pixels; the multiple contour pixels form a closed shape. The total number of pixels within the closed shape formed by the outline pixels is counted and added to the total number of outline pixels to obtain the first total number of pixels.

[0044] The binarization process involves dividing the grayscale value of all pixels in the image into two colors: black and white, based on the difference between the grayscale value and a set grayscale value.

[0045] It should be noted that noise is inevitable in actual captured images. Taking the conversion of glue droplets to black as an example, after binarization, noise in the second image may also be converted to black, in addition to glue droplets. If the total number of black pixels is directly counted, the noise will be included, leading to increased error.

[0046] For the reasons mentioned above, this embodiment first uses edge detection to identify the closed shape formed by the edge of the glue droplet, and then counts the total number of pixels within the closed shape. Finally, the total number of pixels is added to the total number of pixels at the edge of the glue droplet to obtain the first total number of pixels, which can more accurately reflect the area of ​​the glue droplet.

[0047] After the above calculation process, the total number of first pixels is the area of ​​the obliquely sprayed droplets. When the droplets are sprayed at an oblique angle, due to the small amount of horizontal kinetic energy in the droplets, the droplets as a whole extend slightly in the oblique direction. This will cause the area of ​​the droplets to be larger than expected. If the volume is calculated based on the area obtained from vertical spraying, the volume estimate will be too large, which will lead to inaccurate pressure control of the dispensing valve.

[0048] For the reasons mentioned above, this embodiment corrects the identified area and then calculates the volume of the droplet based on the corrected area.

[0049] S4-2: Based on the first included angle, the total number of first pixels is corrected to obtain the total number of second pixels, including: Obtain the correction formula; the correction formula is used to calculate the vertical projection area based on the tilted projection area and the tilt angle; specifically:

[0050] in, Indicates the total number of the second pixel. Indicates the total number of the first pixel. θ Indicates the first angle. α This represents the empirical correction coefficient, in this embodiment... α =0.15.

[0051] Substitute the first total number of pixels and the first included angle into the correction formula to calculate the second total number of pixels.

[0052] For example: if the total number of the first pixel is 15230 pixels 2 Assuming the first angle is 5.2°, the final calculated total number of the second pixels is approximately 15138 pixels. 2 It can be seen that the total number of the second pixel is slightly less than the total number of the first pixel, thus completing the area correction.

[0053] In some cases, if the direction of the adhesive droplet spray is tilted, that is, sprayed vertically, the total number of the first pixel and the total number of the second pixel will be equal after substituting into the correction formula.

[0054] S4-3: Calculate the volume of the glue droplet based on the total number of the second pixels to obtain the first volume, including: Obtain preset calibration coefficients; the preset calibration coefficients are used to characterize the conversion relationship between the area and volume of the droplets in the image; In this embodiment, the calibration coefficient is preset. =5.2×10 -5 mm 3 / pixel 3 .

[0055] The preset calibration coefficient is a constant obtained through experimental calibration. Its value depends on the camera, lens, shooting distance, the entire vision system, and the actual shape of the droplet.

[0056] The methods for obtaining the preset calibration coefficients include: 1. Spray a jet with a standard volume V std (e.g., V) std Droplets of adhesive (0.03 mm³) were generated using a precision micro-syringe and are of known quantity. 2. Along a completely perpendicular direction (the first included angle is...) After the water sprays and drips, an image of it is taken vertically. 3. Using image processing methods, obtain the total number of corrected pixels of this standard glue droplet in the image. (For example, 832,000 pixels²).

[0057] 4. Since the volume V of the droplet is proportional to its projected area of The power (explained below) is... Therefore, the preset calibration coefficients can be derived. :

[0058] As long as the position of the dispensing valve spray point, the position of the high-speed camera, and the shooting direction remain unchanged, the preset calibration coefficient will remain constant. It is a fixed constant used to convert pixel area into volume in all subsequent spraying processes.

[0059] The first volume is calculated based on the preset calibration coefficients and the total number of second pixels. V .

[0060] As can be seen from the preceding text... The actual number is the total number of pixels, and cannot be directly substituted into the area calculation.

[0061] Imagine a drop of glue falling onto a flat surface; its shape is approximately that of a spherical cap (part of a sphere).

[0062] Formula for the volume of a spherical crown:

[0063] in, It is the radius of the base. It refers to the height of the ball's crown.

[0064] Projected area of ​​the spherical crown:

[0065] For small-volume droplets, their spreading is limited, and their shape is more similar to a hemisphere or a spherical cap with a height in fixed proportion to its radius. Under these conditions, the volume can be derived. With projected area of The power is directly proportional to the power.

[0066] Simplified understanding: For a hemisphere, , The derivation yields: .

[0067] Substitute into the volume formula: .

[0068] Therefore, in monocular vision systems where the droplet height cannot be accurately measured, the following method is used: It is an empirical model that achieves a good balance between accuracy and computational simplicity.

[0069] In summary, in this embodiment, the total number of pixels corresponding to the area where the glue droplets fall and their volume satisfy the following relationship:

[0070] Through the above calculation process, the area can be corrected so that the final volume is closer to the actual volume of the glue droplet, thus making the subsequent adjustment of the dispensing valve pressure more accurate.

[0071]

[0072] To verify the effect, the system records and compares the volume before and after correction: The volume of the droplet calculated before correction was approximately 0.0312 mm. 3 ; The volume of the droplet calculated after correction is approximately 0.0300 mm. 3 ; Therefore, the absolute measurement error caused by tilting is 0.0012 mm. 3 The relative error is approximately 4%. Without correction, the system will be based on 0.0312mm. 3 Such erroneous values, when used for pressure adjustment, can lead to incorrect adjustment direction, under-adjustment, or over-adjustment.

[0073] Assuming the preset volume = 0.0320 mm 3 If the uncorrected volume is too small compared to the preset volume, it will lead to under-adjustment in the future.

[0074] After this calibration step, the dispensing valve system can obtain a droplet volume closer to the required volume each time it sprays glue, ensuring the accuracy of subsequent pressure adjustment calculations, thereby guaranteeing the effectiveness and reliability of the entire visual feedback closed-loop control system.

[0075] S5: Based on the first volume and the preset volume of the adhesive droplet, adjust the pressure of the dispensing valve when spraying the adhesive droplet, including: S5-1: Calculate the difference between the preset volume and the first volume to obtain the volume deviation. e ( t ); For example, the preset volume is 0.0320 mm. 3 The corrected droplet volume is calculated to be 0.0300 mm. 3 Then the volume deviation e ( t The value is 0.0020mm. 3 .

[0076] S5-2: Calculate the pressure adjustment amount based on the volume deviation; In this embodiment, the pressure adjustment amount is calculated according to the PID formula. :

[0077] Among them, K p K represents the proportional gain coefficient. i K represents the integral gain coefficient. d represents the differential gain coefficient, and t represents the time variable.

[0078] For example, K p =62500Pa / mm 3 K i =1000Pa / (mm 3 ·s), K d =50 Pa·s / mm 3 The final calculation yielded... =125Pa.

[0079] When applied to different dispensing valve systems, K p K i K d There will be different values, and the final value will depend on the volume deviation. e ( t The pressure adjustment value corresponding to the dispensing valve system is calculated.

[0080] S5-3: Obtain the current dispensing valve pressure value; S5-4: Add the pressure adjustment amount to the current dispensing valve pressure value to calculate the corrected pressure value; S5-5: Adjust the pressure of the dispensing valve to spray the adhesive droplets to the corrected pressure value.

[0081] After the above steps, the corrected pressure value will be 125 Pa higher than the current dispensing valve pressure value.

[0082] In some cases, if the calculation yields If the pressure is -100Pa, the corrected pressure value will be 100Pa lower than the current dispensing valve pressure value.

[0083] Based on the above steps, the impact of tilted injection on volume estimation can be eliminated as much as possible, thereby ensuring the accuracy of pressure regulation and reducing the occurrence of incorrect regulation direction, under-adjustment, or over-adjustment.

[0084] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A method for adjusting a dispensing valve with adaptive pressure feedback, characterized in that, include: S1: Continuously capture multiple first images during the process of the dispensing valve spraying adhesive droplets; the shooting directions of the multiple first images include two mutually perpendicular horizontal directions; S2: Capture a second image of the dripping glue droplets; the second image is captured vertically. S3: Based on multiple images of the first image, calculate the first angle between the straight trajectory of the droplet and the vertical direction; S4: Calculate the first volume of the droplet based on the first included angle and the second image; S5: Adjust the pressure of the dispensing valve when spraying the glue droplets based on the first volume and the preset volume of the glue droplets.

2. The adaptive pressure feedback dispensing valve adjustment method according to claim 1, characterized in that, The step of calculating the first angle between the straight trajectory of the droplet and the vertical direction based on multiple first images includes: Multiple first images are superimposed to form a third image; the third image contains the positions of the droplets in the pixel coordinate system of all the first images; Edge detection is performed on the third image to obtain a set of contour pixels at multiple locations where the droplets are located; Calculate the centroid of each contour pixel set to obtain multiple centroid coordinates; Based on multiple centroid coordinates, the linear trajectory of the droplet during the spraying process is fitted; Obtain the vertical trajectory corresponding to the vertical direction; Calculate the angle between the vertical trajectory and the straight trajectory to obtain the first included angle.

3. The adaptive pressure feedback dispensing valve adjustment method according to claim 1, characterized in that, The calculation of the first volume of the droplet based on the first included angle and the second image includes: S4-1: Identify the total number of first pixels of the glue droplets in the second image; S4-2: Based on the first included angle, the total number of the first pixel is corrected to obtain the total number of the second pixel; S4-3: Calculate the volume of the glue droplet based on the total number of the second pixels to obtain the first volume.

4. The adaptive pressure feedback dispensing valve adjustment method according to claim 3, characterized in that, The total number of first pixels in the second image for identifying glue droplets includes: The second image is binarized, and edge detection is performed on the location of the droplet to obtain multiple contour pixels; the multiple contour pixels form a closed shape. The total number of pixels within the closed shape formed by the outline pixels is counted and added to the total number of outline pixels to obtain the first total number of pixels.

5. The adaptive pressure feedback dispensing valve adjustment method according to claim 3, characterized in that, The step of correcting the total number of first pixels based on the first included angle to obtain the total number of second pixels includes: Obtain the correction formula; the correction formula is used to calculate the vertical projection area based on the tilted projection area and the tilt angle. Substitute the first total number of pixels and the first included angle into the correction formula to calculate the second total number of pixels.

6. The adaptive pressure feedback dispensing valve adjustment method according to claim 4, characterized in that, The step of calculating the volume of the droplet based on the total number of the second pixels to obtain the first volume includes: Obtain preset calibration coefficients; the preset calibration coefficients are used to characterize the conversion relationship between the area and volume of the droplets in the image; The first volume is calculated based on the preset calibration coefficient and the total number of second pixels.

7. The adaptive pressure feedback dispensing valve adjustment method according to claim 1, characterized in that, The step of adjusting the pressure of the dispensing valve when spraying adhesive droplets based on the first volume and the preset volume of the adhesive droplets includes: Calculate the difference between the preset volume and the first volume to obtain the volume deviation; Based on the volume deviation, calculate the pressure adjustment amount; Get the current dispensing valve pressure value; The corrected pressure value is calculated by adding the pressure adjustment amount to the current dispensing valve pressure value. Adjust the pressure of the dispensing valve to spray adhesive droplets to the corrected pressure value.

Images