Dry and wet film cooperative control method based on full-inspection surface density scanner

Abstract

The invention relates to the technical field of dry and wet film cooperative control, in particular to a dry and wet film cooperative control method based on a full-inspection surface density scanner. According to the method, a dry film detection point and a wet film detection point are detected by adopting a full-detection surface density scanner, online fitting is performed by matching the dry film surface density and the original surface density of a wet film, a dry and wet film parameter mapping model is established, cyclic verification is performed on the fitting model to check the Pearson's correlation coefficient and the consistency interval width, and the dry film surface density and the wet film original surface density are calculated. And if the Pearson's correlation coefficient and the consistency interval width both meet the wet film control standard, entering an artificial decision-making layer, and executing a wet film control algorithm after the artificial layer judges that wet film control can be started, otherwise, converting into dry film control. According to the method, a double closed-loop control system is established, and the reliability of fitting data is ensured by adopting a Pearson's correlation coefficient and consistency interval width dual verification mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of wet and dry film collaborative control, and particularly relates to a wet and dry film collaborative control method based on a full-inspection surface density scanner. Background Art

[0002] In the field of coating manufacturing, surface density uniformity is a core index affecting product performance. During the drying process after wet film coating, factors such as solvent evaporation and material shrinkage will cause the surface density distribution to shift. In traditional processes, the quality control of wet films (undried coatings) and dry films (finished products after drying) is usually carried out independently, lacking a dynamic collaborative mechanism.

[0003] The current industry generally adopts the following surface density control method: Detect the surface density value of the dry film through a mobile surface density scanner, and after feedback to the die head closed-loop control software, adjust the position of the die head T-block, thereby controlling the surface density value of the corresponding T-block partition. Since the dry film detection point is usually at the end of the process flow and is far from the actuator (die head), the delay is large and the control lags. To solve the problem of dry film control lag, a wet film surface density monitoring point is set at a position closer to the actuator (die head) in the process flow, and the wet film surface density data is used to assist in control. This method usually uses a scanning surface density meter to scan the wet film surface density value, and after feedback to the actuator (die head) closed-loop software, adjusts the T-block position. Although this method reduces the delay of the control system, the wet film surface density value is affected by factors such as oven temperature and heat uniformity, and usually differs greatly from the surface density value of the final dry film. Therefore, how to accurately fit the wet film and dry film surface densities and then coordinate the dry film control and wet film control is a technical problem to be solved. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a wet and dry film collaborative control method to ensure that while using wet film control to reduce the feedback delay of the coating closed-loop control, the reliability of wet film surface density fitting is improved.

[0005] In view of the deficiencies of the prior art, the technical solution adopted by the present invention to solve its technical problems is: A wet and dry film collaborative control method based on a full-inspection surface density scanner, including the following steps, Step 1: Select the starting coating mode. After the system is initialized, first select the starting coating mode, and the starting coating mode can be selected as wet film starting or dry film starting; Selecting dry film starting enters dry film control; Selecting wet film starting enters Step 2; Step 2: Determine whether the preset starting coating length is reached. If the preset starting coating length is not reached, enter dry film control; If the preset starting coating length is reached, enter Step 3; Step 3: Determine whether it is the first control or the previous control is dry film control. If not, enter dry film control; If so, enter Step 4; Step 4. Online fitting: Perform online fitting on the raw wet film surface density of the first N trips and the dry film surface density of the first N trips collected by the full-inspection surface density scanner. Step 5. Loop verification: Whether the Pearson correlation coefficient and the width of the consistency interval meet the wet film control standard; if both the Pearson correlation coefficient and the width of the consistency interval meet the wet film control standard, then enter Step 6; if any one of the Pearson correlation coefficient and the width of the consistency interval does not meet the wet film control standard, then enter the dry film control. Step 6. Interface selection: Select whether wet film control is required. If it is selected, then enter Step 7. Step 7. Wet film control.

[0006] Preferably, the online fitting process in Step 4 is as follows. a. Collection of raw wet film surface density: The full-inspection surface density scanner has continuously collected the set of raw wet film surface density of the first N trips. , , b. Collection of dry film surface density: The full-inspection surface density scanner has continuously collected the set D of dry film surface density of N trips matching the wet film. ; c. Establish the mapping relationship between the dry film surface density and the raw wet film surface density using a linear regression model: , where is the intercept, is the slope, is the dry film surface density of the i-th trip, is the raw wet film surface density of the i-th trip; d. Obtain the parameters , using the least squares method.

[0007] Preferably, the specific process of dry film control is as follows. Step 1. Obtain the current dry film surface density data. Step 2. Determine whether the average surface density of a single trip meets the standard; if it does not meet the standard, then enter the vertical adjustment logic in Step 3; if it meets the standard, then enter the horizontal adjustment logic in Step 4. Step 3. The vertical adjustment logic includes calculating the target pump speed adjustment amount based on the deviation between the target average surface density and the actual average surface density, and then adjusting the screw pump speed according to the target pump speed adjustment amount; then enter Step 5. Step 4. The horizontal adjustment logic includes traversing the surface density values of each partition, and dynamically adjusting the actuator parameters of the corresponding area in combination with a PID controller according to the surface density values of each partition; then enter Step 5. Step 5: Wait for the system to stabilize. After the pump speed of the screw pump or the adjustment of the actuator is in place, the system will enter the stable waiting stage; Step 6: Switch to wet film control after meeting the wet film control standard.

[0008] Preferably, the specific process of wet film control is as follows. Step 1: Obtain the single-pass fitting areal density data of the wet film; Step 2: Traverse all channels to obtain the real-time areal density measurement values; Step 3: Determine whether it exceeds the coarse adjustment threshold; if it exceeds the coarse adjustment threshold, enter Step 4 for longitudinal coarse adjustment; if it does not exceed the coarse adjustment threshold, enter Step 5 for transverse fine adjustment; Step 4: Longitudinal coarse adjustment. The error between the preset zonal areal density value and the target areal density value is used to generate a compensation signal by the PID controller to drive the corresponding zonal T-block to complete the rapid correction of the longitudinal coating amount; Step 5: Transverse fine adjustment. The coating width is divided into multiple independent control units according to the preset film zone division rule. The range of areal density of each zone is calculated to evaluate the transverse uniformity, and then the fine adjustment amount of each die head T-block is output respectively through the zonal PID controller to achieve precise compensation of the local thickness, thereby reducing the transverse standard deviation; Step 6: Issue the T-block adjustment amount. After completing the longitudinal coarse adjustment or transverse fine adjustment, the system will issue the T-block adjustment amount to the actuator for adjustment; Step 7: Wait for the system to stabilize, start the process stability monitoring module, and continuously detect the key parameters of coating speed and slurry viscosity; Step 8: Switch to dry film control. When the fluctuation ranges of the key parameters of coating speed and slurry viscosity converge within the allowable range, finally trigger the control mode switching instruction to smoothly switch the system from wet film control to dry film control mode, forming a complete process closed-loop.

[0009] Preferably, the calculation process of the Pearson correlation coefficient is as follows: , , where, is the original areal density of the wet film in the i-th pass, is the average value of the original areal densities of the wet film in N passes; is the dry film areal density after fitting the original areal density of the wet film in the i-th pass, is the average value of the dry film areal densities after fitting the original areal densities of the wet film in N passes; r is the Pearson correlation coefficient.

[0010] Preferably, the calculation process of the consistency interval width is as follows: ; ; ; ; Among them, is the width of the consistency interval, is the standard deviation of the difference between the measured dry film surface density and the fitted value of the wet film original surface density, is the average difference between the measured dry film surface density and the fitted value of the wet film original surface density, is the difference between the fitted value of the wet film original surface density in each zone and the measured dry film surface density, and t is the number of zones, is the set of dry film surface densities after fitting the wet film original surface density, , is the dry film surface density after fitting the wet film original surface density in the i-th pass.

[0011] Preferably, N is 20 in step four.

[0012] Preferably, the wet film control standard is that the Pearson correlation coefficient is greater than 0.6 and the width of the consistency interval is less than 3.5.

[0013] Preferably, 、 is calculated as follows, , , , , wherein is the average value of the wet film original surface density in the first N passes, is the average value of the dry film surface density in the first N passes matched with the wet film.

[0014] The beneficial effects of the present invention are as follows: 1. The present invention adopts a full-inspection type surface density scanner The full-inspection type surface density scanner can achieve instantaneous global measurement, eliminate mechanical scanning positioning errors, ensure the spatio-temporal consistency of the dry / wet film original surface density, and improve the surface density matching accuracy; the full-inspection type surface density scanner covers 100% of the detection area in a single measurement, and the efficiency is 3-5 times higher than that of the scanning type; 2. Innovation in coordinated control of dry and wet films A double closed-loop control system (fast response of wet film + precise correction of dry film) is established, and a dynamic fitting model of the surface density in the first N passes is adopted to solve the non-linear mapping problem caused by the physical property differences between dry and wet films, and a double verification mechanism of Pearson correlation coefficient and consistency interval width is adopted to ensure the reliability of the fitted surface density. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1Schematic diagram of a scanning areal density scanner involved in the background art; Figure 2 Schematic diagram of a full-inspection areal density scanner involved in the method of the present invention; Figure 3 Schematic diagram of a dry-wet film collaborative control system involved in the present invention; Figure 4 Logic flowchart of dry-wet film collaborative control involved in the present invention; Figure 5 Logic flowchart of dry film control involved in the present invention; Figure 6 Logic flowchart of wet film control involved in the present invention; Figure 7 Schematic diagram of the correlation with a Pearson correlation coefficient of -0.32 involved in the present invention; Figure 8 Schematic diagram of the correlation with a Pearson correlation coefficient of 0.764 involved in the present invention; Figure 9 Schematic diagram of the fitting effect when the width of the consistency interval is 4.16 involved in the present invention; Figure 10 Schematic diagram of the fitting effect when the width of the consistency interval is 1.93 involved in the present invention; Explanation of reference numerals: 1. Integrated radiation source; 2. Linear constraint collimation hole; 3. Linear array semiconductor detector; 4. Oven; 5. Coating die head. Detailed description of the specific implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. The embodiments of the present invention are given for the purpose of illustration and description, and are not exhaustive or limited to the disclosed form. Many modifications and variations will be obvious to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and enable those of ordinary skill in the art to understand the present invention and thus design various embodiments with various modifications suitable for specific purposes.

[0017] In the existing surface density control technology as described in the background art, both the dry film detection point and the wet film detection point use a scanning surface density meter. The scanning surface density meter may cause inaccurate matching of the surface density of the wet film and the dry film due to factors such as the repeated positioning accuracy of the motor, resulting in unreliable wet film control; the original surface density of the wet film is difficult to synchronize due to the scanning of the scanning surface density meter and is affected by factors such as the temperature of the drying oven, resulting in inaccurate fitting values of the surface density of the wet film and the dry film and being difficult to apply to surface density control. The traditional scanning surface density scanner is based on a single-point or linear array sensor, and drives the probe to scan line by line on the sample surface through a mechanical drive system (such as an X-ray or laser displacement probe), and its scanning path is zigzag or spiral, and it is necessary to collect the surface density point by point at different times, and the measurement time increases linearly with the sample area. The present invention proposes a method for collaborative control of dry and wet films based on a full-inspection surface density scanner. The full-inspection surface density scanner uses a wide-width array sensor or area array imaging technology, and can synchronously capture the surface density distribution of the entire detection area in a single measurement. The surface density is the weight per unit area, and the unit is mg / cm 2 . Its characteristic is to complete the global measurement instantaneously (such as CCD optical imaging or large-area β-ray penetration detection), without mechanical moving parts, and the typical application scenario is the on-line monitoring of continuous production. In the coating process, the repeated positioning accuracy of the mechanical drive system and the deformation from the wet film to the dry film (such as shrinkage caused by solvent volatilization and substrate tension change) will cause coordinate offset, which poses a challenge to data alignment. As Figure 2 shown is a schematic diagram of the full-inspection surface density scanner involved in the method of the present invention, including an integrated ray source 1, a line constraint collimation hole 2 and a linear array semiconductor detector 3. The full-inspection surface density scanner can achieve 100% coverage of the line scan spot and 100% full inspection of the surface density. Due to the instantaneous global measurement characteristics of the full-inspection surface density scanner, the surface density of the wet film and the dry film has natural spatio-temporal consistency. For example, in the coating of lithium battery electrode sheets, the surface density of the dry film at the outlet of the oven can be directly associated with the wet film after wet film detection, and the thickness abnormal area can be quickly located. Based on the above advantages and disadvantages, as Figure 3 shown is a schematic diagram of the system involved in the method of the present invention, including an oven 4 and dry film detection points C and wet film detection points B located on both sides of the oven 4. The length of the foil from the dry film detection point C to the wet film detection point B is m, and the front end of the wet film detection point B is a coating die head. The length of the foil from the coating die head 5 to the wet film detection point B is n. In the present invention, both the dry film detection point C and the wet film detection point B use a full-inspection surface density scanner for detection. By the length m of the foil from the dry film detection point C to the wet film detection point B, the length n of the foil from the coating die head 5 to the wet film detection point B, and the tape running speed v of the foil, calculate the time points when the action point of each control instruction of the coating die head 5 moves to the dry film and wet film scanners, and match the original surface density of the wet film and the surface density of the dry film through the time points, and substitute the matched dry film surface density and the original surface density of the wet film into the fitting model to calculate the dry film surface density fitted from the original surface density of the wet film. Figure 3Among them, S1 is the first dry film control, point A is the first dry film control point, and the state of the first dry film adjustment. At this time, the time is T1; S2 is that the first dry film control part reaches the wet film detection point. When the first dry film control point A adjusted by S1 reaches the wet film detection point B, the time at this time is T1 + n / v; S3 is the first wet film control, point D is the first wet film control point. Because the wet film control requires continuous six trips of data to judge the trend, the algorithm actually calculates based on the six trips of data after S2 and records the time of the sixth trip of data as T2; S4 is that the first wet film control part reaches the dry film detection point C. The first wet film adjustment part adjusted by S3 reaches the dry film detection point C. The travel is m + n, and the coating speed is v. At this time, (m + n) / v seconds have passed since S3; S5 is the second dry film control, point A1 is the second dry film control point. Because the dry film control requires continuous six trips of data to judge the trend, the algorithm actually calculates based on the six trips of data after S4 and records the time of the sixth trip of data as T3.

[0018] Figure 4 This is the dry-wet film collaborative control logic flow chart involved in the present invention, specifically including the following steps; Step 1: Select the starting coating mode. After the system is initialized, first select the starting coating mode. The starting coating mode can be selected as wet film starting coating or dry film starting coating; select dry film starting coating to enter dry film control; select wet film starting coating to enter Step 2; Step 2: Determine whether the preset starting coating length is reached. The starting coating length depends on the on-site process conditions. If the preset starting coating length is not reached, enter dry film control; if the preset starting coating length is reached, enter Step 3; Step 3: Determine whether it is the first control or the previous control is dry film control. If not (not means neither the first control nor the previous one is dry film control), enter dry film control; if so (yes means the first control or the previous one is dry film control), perform online fitting of the original surface density of the wet film; Step 4: Online fitting. Call the first N trips of original wet film surface density and the first N trips of dry film surface density collected by the full-inspection surface density scanner to perform online fitting. The value of N depends on the judgment of the process personnel on the effect of the wet film fitting surface density under actual conditions; The online fitting process in Step 4 is as follows: a. Collection of original wet film surface density: The full-inspection surface density scanner has continuously collected a set of the first N trips of original wet film surface density , ; b. Collection of dry film surface density: The full-inspection surface density scanner has continuously collected a set D of the first N trips of dry film surface density matching the wet film, ; c. Use a linear regression model to establish the mapping relationship between the dry film surface density and the original wet film surface density: , where is the intercept, is the slope, is the dry film surface density of the i-th pass, is the original wet film surface density of the i-th pass; d. Obtain the parameters and by the least squares method; and are calculated as follows: , , , , where is the original wet film surface density of the i-th pass, is the average value of the original wet film surface densities of the first N passes, is the dry film surface density of the i-th pass, is the average value of the dry film surface densities of the first N passes matched with the wet film.

[0019] Assume that the dry film surface densities of 20 passes and their corresponding original wet film surface densities are used for online fitting. When N = 20, the online fitting process is as follows: Collection of original wet film surface density: The full inspection type surface density scanner has continuously collected the set of original wet film surface densities of the first 20 passes , denoted as: , Collection of dry film surface density: The full inspection type surface density scanner has continuously collected the set D of dry film surface densities of 20 passes matched with the original wet film surface density, denoted as: , For and , establish the mapping relationship between the dry film surface density and the original wet film surface density using a linear regression model: , where is the intercept, is the slope.

[0020] Obtain the parameters and by the least squares method: , , , , wherein the average value of the original surface density of the wet film for the first 20 passes, and the average value of the surface density of the dry film for 20 passes matching the wet film.

[0021] Step Five: Cyclic verification. Whether the Pearson correlation coefficient and the width of the consistency interval meet the wet film control standard. The wet film control standard is that the Pearson correlation coefficient > 0.6 and the width of the consistency interval < 3.5; if either the Pearson correlation coefficient or the width of the consistency interval does not meet the wet film control standard, enter the dry film control; if both the Pearson correlation coefficient and the width of the consistency interval meet the wet film control standard, enter Step Six; Step Six: Select whether wet film control is required at the interface. If it is selected, enter Step Seven; Step Seven: Wet film control.

[0022] After system initialization, first select the starting coating mode. The starting coating mode can be selected as wet film starting coating or dry film starting coating; if wet film starting coating is selected, determine whether the preset starting coating length is reached? The preset starting coating length is related to the fitting accuracy of the original surface density of the wet film, and an appropriate length can be selected according to different processes. If the preset wet film starting coating length is reached, enter the wet film control process; if the preset wet film starting coating length is not reached, enter the dry film control process.

[0023] After executing the wet film control strategy, determine whether it is the first control or the previous control was dry film control. If one of the conditions is met, activate the surface density collaborative fitting process, call the full-inspection surface density scanner to collect the original surface density of the first 20 passes of the wet film and the surface density of the first 20 passes of the dry film to perform online fitting, and establish a mapping model of wet and dry film parameters.

[0024] Perform cyclic verification on the fitting model, focusing on verifying the Pearson correlation coefficient r (the Pearson correlation coefficient measures the linear correlation of the surface density) and the width of the consistency interval (the width of the consistency interval represents the tolerance range of the prediction deviation). If the Pearson correlation coefficient r and the width of the consistency interval meet the wet film control standard, enter the artificial decision-making layer, and manually judge whether the current process meets the wet film control standard. After the manual layer judges that wet film control can be enabled, execute wet film control; otherwise, switch to dry film control.

[0025] Figure 7 The medium orange line S1, Figure 8 the medium orange line S 11 is the dry film surface density curve (the dry film surface density curve comes from the surface density data sent by the surface density scanner at the dry film detection point), Figure 7 the medium blue line S2, Figure 8 the medium blue line S22 is the fitting curve of the wet film surface density data (the wet film surface density data is sent by the surface density scanner at the wet film detection point), where Figure 7 the Pearson correlation coefficient r is -0.32, Figure 8 the Pearson correlation coefficient r of Figure 8 is 0.764. It can be seen that the trend correlation between the dry film curve fitted from the wet film in Figure 7 is relatively strong, while the correlation in

[0026] is relatively weak. Generally speaking, the closer the Pearson correlation coefficient r is to 1, the stronger the positive correlation. Therefore, in wet film control, the Pearson correlation coefficient r of the latest time will be detected to judge whether the fitting effect of the original surface density of the current wet film segment is suitable for wet film control. The calculation process of the Pearson correlation coefficient r is as follows: where is the original surface density of the wet film for the i-th pass, is the mean value of the original surface density of the wet film for N passes; is the dry film surface density after fitting the original surface density of the wet film for the i-th pass, is the mean value of the dry film surface density after fitting the original surface density of the wet film for N passes; the closer r is to 1, the stronger the linear positive correlation between the dry film surface density after fitting according to the original surface density of the wet film and the actually detected dry film surface density. The set of dry film surface densities after fitting the wet film is is the dry film surface density after fitting the original surface density of the i-th pass wet film, and the set of actually detected dry film surface densities is D.

[0027] Figure 9 the orange line in Figure 10 is the actually detected dry film surface density curve S3, 33 Figure 9 the blue line S4 in Figure 10 the blue line S in 44 is the curve fitted from the wet film surface density data, where Figure 9 the consistency interval of S3 and S4 in Figure 10 is [-1.15, 3.01], and the width of the consistency interval is 4.16, indicating that compared with the dry film surface density, the difference fluctuation of the wet film fitting surface density is large, the standard deviation of the difference is large, and the fitting effect is not good. 33 S in 44The consistency interval is [-1.17, 0.76], the width of the consistency interval is 1.93, the difference range is narrower, and the standard deviation of the difference value is smaller, indicating that the wet film fitting value is more accurate. Therefore, the width of the latest consistency interval will be detected during wet film control. , and this is used to determine whether the fitting effect of the original surface density of the wet film in the current section is suitable for wet film control.

[0028] Width of the consistency interval The calculation process is as follows: The set of dry film surface densities after wet film fitting is , , The set of actually detected dry film surface densities is D, , the number of partitions is t, and the difference between the wet film surface density fitting value and the detected dry film surface density in each partition is calculated : , Then the average difference value between the detected dry film surface density and the wet film surface density fitting value is: , The standard deviation of the difference between the detected dry film surface density and the wet film surface density fitting value is: , Then the width of the consistency interval is: .

[0029] Figure 5 This is the dry film control logic flowchart involved in the present invention, which specifically includes the following steps. Step 1: Obtain the current dry film surface density data (sent by the full-inspection surface density scanner at the dry film detection point); Step 2: Determine whether the average surface density of a single trip meets the standard; if not, enter the longitudinal adjustment logic in Step 3; if it meets the standard, enter the transverse adjustment logic in Step 4; Step 3: The longitudinal adjustment logic includes calculating the target pump speed adjustment amount according to the deviation between the target surface density average value and the actual surface density average value, and then adjusting the screw pump speed according to the target pump speed adjustment amount; then enter Step 5; Step 4: The transverse adjustment logic includes traversing the surface density values of each partition, and combining with the PID controller according to the surface density values of each partition. The PID controller dynamically adjusts the parameters of the actuator in the corresponding area; then enter Step 5; Step 5: Wait for the system to stabilize. After the screw pump speed or the actuator adjustment is in place, the system will enter the stable waiting stage; Step 6: Switch to wet film control after meeting the wet film control standard.

[0030] The above dry film control logic process starts with obtaining the current dry film surface density data, and then judges whether the average surface density of a single pass meets the standard: if the average surface density of a single pass meets the preset threshold range, it enters the transverse adjustment logic. By traversing the measured surface density values of each partition of the coating width, the PID controller is combined to dynamically adjust the parameters of the actuator corresponding to the area; if the average surface density of a single pass does not meet the standard, it turns to the longitudinal adjustment logic. First, calculate the target pump speed adjustment amount of the screw pump according to the deviation between the target surface density average value and the actual surface density average value, and then drive the pump speed adjustment mechanism to complete the correction of the overall longitudinal coating amount. After completing the transverse or longitudinal adjustment operation, the system will enter the stable waiting stage, and switch to wet film control after meeting the wet film control standard.

[0031] Figure 6 The wet film control logic flow chart involved in the present invention specifically includes the following processes: Step 1. According to Figure 3 After the system obtains the original wet film surface density and the corresponding dry film surface density, through fitting calculation of the original wet film surface density and the corresponding dry film surface density, the single-pass fitting surface density of the wet film is obtained; Step 2. Traverse the wet film fitting surface density of all channels to obtain the real-time wet film fitting value; Step 3. Judge whether it exceeds the coarse adjustment threshold; if it exceeds the coarse adjustment threshold, enter Step 4 for longitudinal coarse adjustment; if it does not exceed the coarse adjustment threshold, enter Step 5 for transverse fine adjustment; Step 4. Longitudinal coarse adjustment. The error between the preset partition surface density value and the target surface density value is generated by the PID controller to generate a compensation signal to drive the corresponding partition T block to complete the rapid correction of the longitudinal coating amount; Step 5. Transverse fine adjustment. The coating width is divided into multiple independent control units according to the preset film area division rules, and the range of surface density of each partition is calculated to evaluate the transverse uniformity. Then, the fine adjustment amount of each T block is output by the partition PID controller respectively to achieve precise compensation of the local thickness, thereby reducing the transverse standard deviation; Step 6. Issue the T block adjustment amount. After completing the longitudinal coarse adjustment or transverse fine adjustment, the system will issue the T block adjustment amount to the actuator for adjustment; Step 7. Wait for the system to stabilize, start the process stability monitoring module, and continuously detect key parameters such as coating speed and slurry viscosity; Step 8. Switch to dry film control. When the fluctuation ranges of key parameters such as coating speed and slurry viscosity converge within the allowable range, finally trigger the control mode switching instruction, and smoothly switch the system from wet film control to dry film control mode to form a complete process closed loop.

[0032] The wet film control logic process starts with obtaining the single-pass fitted areal density of the wet film. The system first traverses the real-time areal density measurement values of all channels, and then enters the adjustment threshold judgment stage: it determines whether the current areal density distribution exceeds the preset coarse adjustment threshold range through a diamond decision box. If it exceeds the threshold (Y branch), the longitudinal coarse adjustment mechanism is activated, and the error between the prefabricated partition areal density value and the target value generates a compensation signal through a PID controller to drive the corresponding partition T block to complete the rapid correction of the longitudinal coating amount. If it does not exceed the threshold (N branch), it enters the transverse fine adjustment stage. The coating width is divided into multiple independent control units according to the preset film area division rules, the areal density range of each partition is calculated to evaluate the transverse uniformity, and then the fine adjustment amount of each T block is output respectively through the partition PID controller to achieve precise compensation of the local thickness, thereby reducing the transverse standard deviation. After completing the longitudinal or transverse adjustment, the system issues the T block adjustment amount to the actuator, and simultaneously activates the process stability monitoring module, continuously detecting key parameters such as coating speed and slurry viscosity until their fluctuation ranges converge within the allowable range, and finally triggering a control mode switching instruction to smoothly transition the system from the wet film dynamic adjustment state to the dry film steady-state control mode, forming a complete process closed-loop.

Claims

1. A dry-wet film collaborative control method based on a full-inspection type surface density scanner, characterized in that: It includes the following steps: Step 1: Select the starting coating mode. After the system initialization, first select the starting coating mode. The starting coating mode can be selected as wet film starting coating or dry film starting coating. Selecting dry film starting coating enters the dry film control. Selecting wet film starting coating enters Step 2. Step 2: Determine whether the preset starting coating length is reached. If the preset starting coating length is not reached, enter the dry film control. If the preset starting coating length is reached, enter Step 3. Step 3: Determine whether it is the first control or the previous control is dry film control. If not, enter the dry film control. If so, enter Step 4. Step 4: Online fitting. Call the first N trips of wet film original surface density and the first N trips of dry film surface density collected by the full inspection type surface density scanner to perform online fitting. Step 5: Loop verification. Whether the Pearson correlation coefficient and the width of the consistency interval meet the wet film control standard. If both the Pearson correlation coefficient and the width of the consistency interval meet the wet film control standard, enter Step 6. If any one of the Pearson correlation coefficient and the width of the consistency interval does not meet the wet film control standard, enter the dry film control. Step 6: Interface selection. Select whether wet film control is required. If it is selected, enter Step 7. Step 7: Wet film control.

2. The wet and dry film collaborative control method based on the full-inspection surface density scanner according to claim 1, wherein: The process of online fitting in Step 4 is as follows: a. Wet film original areal density acquisition: The full-inspection areal density scanner has continuously acquired the set of the original areal densities of the wet films in the first N runs , ， b. Dry film areal density acquisition: The full-inspection areal density scanner has continuously acquired N sets of dry film areal density collections D that match the wet film, ; c. Use a linear regression model to establish the mapping relationship between the dry film surface density and the wet film original surface density: ， wherein is the intercept, is the slope, is the dry film surface density of the i-th pass, is the original wet film surface density of the i-th pass; d. Obtain the parameters by the least squares method and .

3. The wet and dry film collaborative control method based on the full-inspection surface density scanner according to claim 1, wherein: The specific process of dry film control is as follows: Step 1: Obtain the current dry film surface density data. Step 2: Determine whether the average surface density of a single trip meets the standard. If it does not meet the standard, enter the vertical adjustment logic in Step 3. If it meets the standard, enter the horizontal adjustment logic in Step 4. Step 3: The vertical adjustment logic includes calculating the target pump speed adjustment amount according to the deviation between the target surface density average value and the actual surface density average value, and then adjusting the screw pump speed according to the target pump speed adjustment amount. Then enter Step 5. Step 4: The horizontal adjustment logic includes traversing the surface density values of each partition, and combining with the PID controller according to the surface density values of each partition. The PID controller dynamically adjusts the actuator parameters of the corresponding area. Then enter Step 5. Step 5: Wait for the system to stabilize. After the screw pump speed or the actuator adjustment is in place, the system will enter the stable waiting stage. Step 6: Switch to wet film control after meeting the wet film control standard.

4. The wet and dry film collaborative control method based on a full-inspection type surface density scanner according to claim 1, wherein: The specific process of wet film control is as follows: Step 1: Obtain the single-trip fitting data of the wet film surface density. Step 2: Traverse all channels to obtain the real-time surface density measurement values. Step 3: Determine whether it exceeds the coarse adjustment threshold. If it exceeds the coarse adjustment threshold, enter the vertical coarse adjustment in Step 4. If it does not exceed the coarse adjustment threshold, enter the horizontal fine adjustment in Step 5. Step 4: Vertical coarse adjustment. The error between the preset partition surface density value and the target surface density value that exceeds is generated by the PID controller to generate a compensation signal to drive the corresponding partition T block to complete the rapid correction of the longitudinal coating amount. Step 5: Horizontal fine adjustment. Divide the coating width into multiple independent control units according to the preset film area division rule, calculate the surface density range of each partition to evaluate the horizontal uniformity, and then output the fine adjustment amount of each die head T block through the partition PID controller respectively to achieve precise compensation of the local thickness, thereby reducing the horizontal standard deviation. Step 6: Issue the T-block adjustment amount. After completing the longitudinal coarse adjustment or the lateral fine adjustment, the system will issue the T-block adjustment amount to the actuator for adjustment; Step 7: Wait for the system to stabilize. Start the process stability monitoring module and continuously detect key parameters such as coating speed and slurry viscosity; Step 8: Switch to dry film control. When the fluctuation ranges of the key parameters of coating speed and slurry viscosity converge within the allowable range, finally trigger the control mode switching instruction to smoothly switch the system from wet film control to dry film control mode, forming a complete process closed-loop.

5. The wet and dry film collaborative control method based on the full-inspection type surface density scanner according to claim 2, characterized in that: The calculation process of the Pearson correlation coefficient is as follows: ， ， wherein, is the original surface density of the wet film in the i-th pass, is the average value of the original surface density of the wet film in N passes; is the surface density of the dry film after fitting the original surface density of the wet film in the i-th pass, is the average value of the surface density of the dry film after fitting the original surface density of the wet film in N passes; r is the Pearson correlation coefficient.

6. The wet and dry film collaborative control method based on the full-inspection type surface density scanner according to claim 5, wherein: The calculation process of the width of the consistency interval is as follows: ； ； ； ； Among them, is the consistency interval width, is the standard deviation of the difference between the measured dry film surface density and the fitted value of the wet film original surface density, is the average difference between the measured dry film surface density and the fitted value of the wet film original surface density, is the difference between the fitted value of the wet film original surface density in each partition and the measured dry film surface density, where t is the number of partitions, is the set of dry film surface densities after fitting the wet film original surface density, , is the dry film surface density after fitting the wet film original surface density in the i-th pass.

7. The wet and dry film collaborative control method based on the full-inspection type surface density scanner according to claim 1, wherein: In Step 4, N is 20.

8. The wet and dry film collaborative control method based on the full inspection type surface density scanner according to claim 6, wherein: The wet film control standard is that the Pearson correlation coefficient is greater than 0.6 and the width of the consistency interval is less than 3.

5.

9. The wet and dry film collaborative control method based on the full-inspection type surface density scanner according to claim 2, wherein: , The calculation method is as follows: ， ， , , Among them is the average value of the original surface density of the wet film for the first N passes, is the average value of the surface density of the dry film for the first N passes that matches the wet film.

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