How to estimate the quality of a sheet roll

Abstract

To enable a plant operator to simultaneously view and analyze data that are derived from a plurality of sensors.SOLUTION: An apparatus for and a method of inferring quality of a sheet roll consecutively monitors new data including: (a) surface defects of the sheet roll from a vision defect tracking system, (b) measurement defects of the sheet roll from a vision measurement system, and (c) quality and defect data of the sheet roll from a quality control system, and simultaneously integrating the new data with old data in history. A data connect application programming interface can furnish historical, current and alarms data for analysis to an aggregator node for reporting and analysis.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention generally relates to quality control of continuous sheet materials, and more particularly, to obtaining defect measurement values for monitoring sheet materials such as electrodes used in lithium ion batteries using a plurality of sensors and displaying the results in an integrated and easily visualized manner. A high-performance defect map combining various measurement data enables an operator to view the defect map on one screen.

Background Art

[0002] Online measurement is used to detect the characteristics of sheet materials during manufacturing to enable the facilitated control of the sheet manufacturing process and thus ensure sheet quality while reducing the amount of out-of-specification sheet materials produced. For example, in the production of electrodes for lithium ion batteries, metal foils from metal rolls are continuously coated with a mixture of active materials. A cutting machine cuts the completed coated metal foil into electrode sheets that are assembled into cells and batteries. To achieve and maintain the quality of continuous roll-to-roll production of electrodes, constant online measurement of quality factors that are strongly linked to battery performance is necessary. If upstream defects are not detected and corrected or removed, defective batteries are produced. For example, there are a plurality of individual defect monitoring systems used in lithium ion battery production, including a vision system (camera) and a quality control system (QCS) scanning system.

[0003] One of the main problems in performing online measurement during sheet production is that the physical properties of the sheet material usually vary in the machine direction (MD) and the cross direction (CD). The machine direction refers to the direction of movement of the sheet material during manufacturing, and the term "cross direction" refers to the direction across the surface of the sheet perpendicular to the MD.

[0004] To detect variations in sheet material, a scanning sensor is used that periodically traverses the sheet manufacturing machine across the CD, detecting selected sheet characteristic values ​​such as basis weight or caliper along each scan. Typically, the sheet being produced is traversed from edge to edge during each scan.

[0005] In practice, the measurement information provided by the scanning sensor is typically assembled after each scan to provide a profile of the sheet characteristics detected by the CD. In other words, each profile consists of a series of sheet measurements at adjacent locations in the lateral direction. The purpose of the profile is to enable easy detection of lateral variations in sheet characteristics. Based on the detected lateral variations in the detected sheet characteristics, appropriate control adjustments can be made to the sheet manufacturing machine with the aim of reducing the variations in both the CD and MD profiles.

[0006] A scanning sensor that periodically traverses a sheet at a constant speed cannot measure selected sheet characteristics at locations precisely aligned perpendicular to the longitudinal edge of the sheet. Due to the sheet speed, the scanning sensor actually moves diagonally across the sheet surface, and as a result, the successive scanning paths have a zigzag pattern with respect to the direction perpendicular to the longitudinal edge of the sheet. As is obvious, the scanning sensor measures only small portions of the sheet along the diagonal zigzag pattern. In practice, it is typical to calculate the average of the profile measurements over each scan. Such an average is often called the "final" average because it is calculated after each scan is completed.

[0007] Most manufacturing plants use monitors that display real-time measurement data in the form of a color map showing the variability detected on a sheet. As shown in Figure 17, MD data from the sensor is shown in six vertical columns. The columns represent different strips on the coating. For example, in the case of a six-strip coating section, the visualization also shows six strips. Thus, all columns are acquired simultaneously. The leftmost column represents the most recent data, and the last column on the right represents the previous data. The top of the leftmost column is the real-time current data. The color legend on the left is a scale that correlates a specific hue (not shown) to a specific measured quantity. For each of the six columns or map, the column width corresponds to the CD of the sheet being monitored. The map monitors patterns of data variation that can indicate several underlying defects. Different values ​​are given specific colors and plotted on the map. As the values ​​change, the operator can observe the variability of the corresponding color, and by observing this, the operator can infer the variability from a threshold.

[0008] Color maps are difficult to interpret because operators need to keep in mind what each color and pattern change means. Operators can only assume that a pattern change is a defect, but there may not be a clear indication that a defect is present. In lithium-ion batteries, there are various types of defects that can affect the surface, such as decarburization, bubbling, bubbles, holes, craters, and dark spots. It is impossible to identify which type of defect has been detected using color mapping.

[0009] Furthermore, in a scanning sensor that moves across the sheet width to acquire deviations along a zigzag pattern, the scanning path is a diagonal line across the sheet. The position is represented as a single CD position on the color map. The diagonal is represented by a single horizontal line on the color column or map. This distorts the operator's view and does not indicate defects that fall in areas not within the scanning path.

[0010] The plant also displays measurement data in a profile view to monitor variability and defects on the sheets. The plot above in Figure 18 shows the (measured) basis weight (g / m²) of the sheets. 2 Figure 18 shows the basis weight versus bin. Intersection with either of the two (dashed) threshold lines means that there is a defect in that area of ​​the sheet with respect to basis weight. The plot below Figure 18 shows scanner speed (mm / sec) versus bin. The operator can monitor a view of the basis weight versus bin profile for threshold line violations.

[0011] In current manufacturing technology, both scanning and fixed monitoring systems are positioned at different strategic locations along the MD. Some monitoring systems are placed early in the process, while others are placed further downstream. In this way, different upstream stages of the manufacturing process are monitored, and the data is available to the plant operator. Therefore, any particular point (or section) along the MD of a sheet of processed material can, for example, be subjected to different protocols at different times. However, defect detection and monitoring systems are independent, making it difficult for plant operators and engineers to monitor and analyze data from various systems. In particular, operators / engineers must manually correlate the analysis of multiple systems on the same section of the material sheet in order to make critical decisions regarding quality manufacturing. Constrained by these less-than-user-friendly systems, operators are unable to perform effective analysis and decision-making in real time. As a result, the percentage of defective batteries that must be discarded increases. [Overview of the project]

[0012] This invention relates to an integrated quality monitoring technology that enables plant operators to simultaneously view and analyze data obtained from multiple sensors. In the case of lithium-ion battery manufacturing, operators can identify upstream quality issues, such as defects from the anode or cathode section within the calendar processing section. Operators can perform effective real-time analysis of sheet coatings from multiple sensor and camera systems. Once defects are detected within a continuous material sheet, and the location and source of the defects are identified, operators can quickly initiate appropriate corrective actions to resolve the problem.

[0013] Various embodiments of the present invention include apparatus and methods for estimating the quality of a sheet roll, which include continuously monitoring new data, including surface defects of the sheet roll from a visual defect tracking system, measurement defects of the sheet roll from a visual measurement system, and quality and defect data of the sheet roll from a quality control system, and simultaneously integrating the new data with older historical data.

[0014] In one embodiment, the present invention relates to a method for monitoring the formation of a continuous material sheet moving in the mechanical direction (MD), comprising (a) measuring the sheet properties of the continuous material sheet, and (b) displaying sheet information corresponding to the measured sheet properties on a display device, wherein the sheet information includes an image representing the continuous material sheet and identifying the MD position of the selected sheet measurement properties.

[0015] In another embodiment, the present invention relates to a system for monitoring the manufacturing of a continuous sheet moving in the machine direction (MD), comprising: a computer device configured to receive sheet information signals from a plurality of sensors measuring one or more characteristics of the sheet; and a display device configured to generate an integrated image on a display screen in response to sheet information from two or more of the plurality of sensors.

[0016] The integrated quality measurement view of the present invention is exemplified by monitoring views, analysis views, and reporting views. Monitoring views can be used to view a combined view of all defects aggregated from the different systems described above, or to view the unintegrated views of each system individually. These can also be used by the operator to manually flag areas if the operator wishes to disable or complement algorithmic automatic flagging. Analysis views can be used to delve into the data and analyze defect patterns, defect counts based on type, instances of defect occurrence, trend analysis, and perform several other quantitative and qualitative analyses. The operator can choose either an aggregated view for analysis or a decomposed view of defect data for analysis. Reporting views are used to report defect information in various details, which can be selected using different filters supported within the system. Users can view reports from each system individually.

[0017] Integrated quality monitoring allows plant operators to view (1) defects by category, severity, and density from QCS and visual systems, (2) the exact size and location of defects, and (3) the real-time location of defects. Periodic defect display identifies deviations in machine parameters. Operators can flag areas that need to be analyzed later, and the system can automatically flag areas with problems requiring immediate attention. Operators can apply a flag filter to view all areas automatically flagged by the system. This feature helps in the rapid identification of defective areas in future analysis. Furthermore, based on manual flagging patterns, the system can begin predicting potential critical areas.

[0018] The system uses multiple cameras and scanners, which allows for correlation between defects from various processes. For example, a hole defect originating from the coating process can be seen as closed after the drying process. Defect lifetimes can be easily monitored using flexible multi-selection views. Operators can also select views by process (drying, coating, etc.) or asset (camera 1, scanner 1, etc.). By comparing the defect map with a color map, operators can see how certain deviations are formed before actual defects appear.

[0019] Although the present invention is exemplified as being implemented in lithium-ion battery production, it is understood that the present invention is applicable to other continuous sheet manufacturing processes, such as in the manufacture of paper, rubber sheets, plastic films, and metal foils. [Brief explanation of the drawing]

[0020] [Figure 1A] This figure shows a roll-to-roll sheet production system for continuously coating a metal substrate with an anode material or cathode material. [Figure 1B] This is a diagram showing the calendar processing process. [Figure 2A] This is a plan view showing a system for applying reference marks to a continuously moving sheet. [Figure 2B] This is a plan view illustrating electrode fabrication using a reference marker to establish measurement traceability by reading a reference mark on a continuously moving sheet and adjusting the measurement using the mark. [Figure 2C] This diagram shows the flow of data and logic. [Figure 3] This is a schematic diagram of the monitoring and control system. [Figure 4] This defect map combines various measurement data and exhibits three main features: defect monitoring, analysis, and diagnosis / reporting of defects in sheet rolls. [Figure 5]A defect map that displays the basic details of the roll. [Figure 6] A defect map that displays various filter options. [Figure 7] A defect map that displays various filter options. [Figure 8] A defect map that displays the details of specific individual defects. [Figure 9] A defect map that displays the details of defects with a selected area. [Figure 10] A defect map that displays the color map of the selected area. [Figure 11] A defect map that displays WIS surface defects. [Figure 12] A defect map that displays WIS measurement defects. [Figure 13] A defect map that displays QCS defects. [Figure 14] A defect map that displays data analysis. [Figure 15] A defect map that displays data analysis. [Figure 16] A defect map that displays a report. [Figure 17] A prior art map that displays the variation of sheet characteristics. [Figure 18] A prior art profile view that displays the variation of sheet characteristics and defects.

Mode for Carrying Out the Invention

[0021] Figure 1A shows a process for coating a metal web or sheet used in the fabrication of electrodes for lithium-ion electrochemical cells and batteries. To fabricate the anode, the electrode coating contains an anode active material such as graphite, and to fabricate the cathode, the electrode coating contains a cathode active material such as lithium metal oxide. The electrode comprises a current collector metal foil coated on both sides of the foil with an electrode slurry which may also contain carbon black, a binder, and a solvent. After applying the electrode slurry to the sides of the foil, the wet-coated foil is heated in a dryer to extract the solvent, leaving a solid layer of electrode material adhering to the metal foil. Copper foil is a preferred anode current collector material, and aluminum foil is a preferred cathode current collector material.

[0022] As shown in Figure 1A, roll 2 is unwound by a winding machine and supplies a continuous metal web or sheet 30 whose upper surface is coated with a layer of electrode slurry by coater 6. The basis weight, thickness, and other characteristics of the metal web or sheet 30 from roll 2 are generally known. Scanning beta gauges 4 and 8 are used, respectively, to measure the basis weight and / or thickness before and after the electrode slurry is applied by coater 6.

[0023] The coater 6, such as a tape casting coater, includes an actuator that controls a slot die / doctor blade to adjust the amount of slurry extruded onto the sheet 30. The dryer 10 removes excess solvent and cures the slurry on the moving coated sheet 32 ​​to form an electrode layer on the sheet. Imaging devices 58 and 78 acquire surface images of the coated sheet 32 ​​before and after the dryer 10. Each imaging device typically includes a camera and a light source that illuminates the surface of the coated sheet 32. The imaging devices may be fixed or scanning. In the case of a fixed device, the camera captures a digital image of the surface of the coated sheet 32 ​​across its entire width. The camera generates a series of images that can be superimposed to form a continuous image of the entire coated sheet 32.

[0024] A scanning beta gauge 12 measures the basis weight and / or thickness of the moving coated sheet 32 ​​as it exits the dryer 10 after the calendar 54. The rolling supports 34, 36 then reverse the orientation of the moving sheet 38 so that the uncoated side is facing upwards, and then the coater 14 applies a layer of electrode slurry to the uncoated upper surface of the moving sheet 38. The basis weight and / or thickness of the double-sided coated sheet 40 is measured by the scanning beta gauge 16 before it enters the dryer 18. Imaging devices 70 and 72 acquire images of the upper and lower surfaces of the sheet before it enters the dryer 18, and imaging devices 74 and 76 acquire images of the upper and lower surfaces of the sheet after it exits the dryer 18.

[0025] Further downstream, a beta gauge housed with an infrared temperature sensor in the scanning device 24 measures the basis weight and / or thickness and temperature of the double-sided coated sheet 42 as the scanning device 24 moves back and forth across the sheet 42. The winding machine takes the double-sided coated sheet 42 into a roll 44. Surface defects on the top and bottom coatings are monitored by imaging devices 26 and 28.

[0026] Figure 1B shows the calendering process in which the double-sided coated electrode layer from the roll 62 passes through the calender 54 for finishing and smoothing. Next, the basis weight and / or thickness of the double-sided coated sheet is measured with a scanning beta gauge 56, and imaging devices 22 and 20 acquire images of the top and bottom surfaces before they are collected on the roll 80. The scanner and camera are part of the quality control system (QCS).

[0027] In order to monitor the double-sided coated sheet 42 in this invention, thermographic image data of the coated sheet 42 is correlated and corrected with online basis weight and / or thickness measurements of the coated sheet 42 to generate a more accurate basis weight and / or thickness calculation across the coated current collector along its entire transverse (CD) direction.

[0028] During manufacturing as shown in Figures 1A and 1B, a continuous sheet 30 may be marked to identify its position along the MD. For example, a reference mark or marking and associated tracking code (collectively referred to as “reference markers”) serves as a reference point along the MD. Figure 2A shows a system for applying a series of reference markers, including reference marks or markings and associated tracking codes, onto a moving material sheet 80. A stationary marker device 82 is positioned above the sheet to provide a series of reference markers 86 along one edge of the moving sheet, and a stationary marker device 84 is positioned above the sheet to provide another series of reference markers 88 along the opposite edge of the moving sheet. Each series of reference markers is aligned along the MD. If the sheet is cut along the MD, each of the series of reference markers may be used separately. The reference mark or marking consists of a horizontal line perpendicular to the MD and a vertical line parallel to the MD. Preferred configurations of the reference mark are a cross or a plus “+” sign. Consecutive horizontal elements or components of a reference mark may be separated by a distance D. Vertical elements or components of a reference mark may be formed at a specific known distance from adjacent sheet edges. A tracking code uniquely identifies each associated reference mark 82, 84. The sheet 80 is supported and transported by rollers 94, and its speed is monitored by an encoder 98. The marker device may be any suitable device that produces sufficiently permanent marks on metal substrates and / or coatings. For example, marking may be done using a laser on metal, or using an inkjet printer on paper, plastic, and cloth.

[0029] During operation, computer 100 adjusts motor 96 to control MD speed. A computer including a processor and storage (memory), such as a laptop computer, may be used. Markers 82 and 84 each periodically mark uncoated or coated areas of the sheet using a reference marker, which is tracked to time or roll encoder measurement generated by encoder 98. The code from encoder 98 may be, for example, an encoder count, millisecond time, or a number or computer-readable code associated with such quantity. The code is stored in database 102. The code is unique and cannot be duplicated. As further described herein, readers 90, 92, such as optical character recognition detectors, scan the reference markers 82, 84. It is understood that the reference markers 82, 84 may be applied to any portion of the moving sheet 80 including uncoated and / or coated areas.

[0030] Figure 2B shows the use of reference markers 82, 84 when tracking different measurements of the electrode layer on a moving sheet. The electrode layer 110 is coated onto a moving metal substrate that is supported by rollers 112 operated by a motor 114 and transported to the MD. An encoder 116 monitors the speed of the rollers 112. A reader 118 recognizes reference marker features 126 on the uncoated side of the moving sheet. A frame 120 supports a scanning device 122 which includes gauges for measuring the basis weight and / or thickness of the coated sheet. The scanning device periodically traverses the coated sheet 110 at a generally constant speed. Gauges for measuring spots or areas 124 of the coated sheet 110 are shown. Due to the sheet speed, the scanning device moves diagonally across the surface of the coated sheet, and as a result, the continuous scanning path has a zigzag pattern with respect to the direction perpendicular to the longitudinal edge of the coated sheet 110. An example of such a zigzag pattern is the scan path 128 tracked by the gauge as the scanning device 122 traverses the surface of the sheet during a series of forward and backward scans. The angle of the scan path relative to the true CD depends on the transverse (CD) speed of the scanning device and the known mechanical (MD) speed of the coated sheet 110. The zigzag pattern of the survey spot covers a relatively small portion of the surface of the coated sheet 110.

[0031] The computer 130 adjusts the measurements by the scanning device 122 so that the locations of the survey spots within the pattern 128 are recorded in the database 132 along with their corresponding reference markers. In this way, the measurements performed at each electrode become known.

[0032] Another feature is that a reference marker may be used to synchronize subsequent measurements with previous measurements. For example, the coated sheet 110 in Figure 2B, after being measured by sensor 122, can be moved to another line for further processing such as drying or calendering. The coated sheet 140, thus processed, is then formed and subjected to a second measurement. The sheet is supported on rollers 142, and a frame 150 holds the second scanner device 152 in place. Computer 130 controls motor 144, encoder 146, and scanner device 152 to synchronize the second measurement by scanner device 152 with the first measurement performed downstream by scanner device 122. Reader 148 detects reference marker 156, and scanning device 152 can be reset to begin measuring at survey spot 154 so that the survey spot in pattern 158 matches the survey spot in zigzag pattern 128.

[0033] If scanners 122 and 152 are well aligned so that when scanner 122 is in a first scanner position along the CD and detects a specific reference marker, the edge of the coated sheet is measured in the same scanner bin on both scanners, then when scanner 152 detects the same specific reference marker, scanner 152 should also be in the same first scanner position along the CD. However, in practice, even if the scanners are well aligned, the moving coated sheet may wobble from side to side on the CD, and therefore the operation must be adjusted to account for this movement by using edge detection. The edge of the moving sheet can be specified as being detected at a specific reference marker xxx + encoder count. In particular, the computer will receive a signal when one of the reference markers is read. However, these may be far apart so that encoder signals can be used to monitor the sheet between consecutive reference markers. In particular, since encoders transmit pulses at a much higher rate, the computer can use the pulses to interpolate the position between reference markers. The same applies to the next scanner in the process.

[0034] When a second measurement is performed by the scanning device 152, the location of the survey spot within the pattern 158 is recorded in the database 132 along with the corresponding reference marker. Thus, the database contains a library of the first and second measurements performed on essentially the same survey spot.

[0035] This invention enables real-time monitoring of the sheet manufacturing process. The display may run on a PC, laptop computer, tablet computer, smartphone, or other portable, mobile, or handheld device.

[0036] Figure 2C shows a system for generating process quality data from online measurements in a continuous electrode manufacturing plant. The system includes various scanners 624 and cameras 618, a QCS server 614, a surface defect detection system and a visual measurement system 600, an aggregator node 610, and an encoded pulse generator and a network time protocol synchronization service 620.

[0037] A laser etcher / marker is used to mark identifiers on the edges of the electrode substrate surface at pre-configured fixed length intervals so that the identifiers are present in all frames captured by the camera system. These identifiers can be used to identify the length of the substrate / material currently being inspected. The identifiers can be barcodes, QR codes, or any other numeric / alphanumeric ID(622) understood by various systems within the solution.

[0038] All data generated from various systems (camera systems, surface defect detection systems, visual measurement systems, and QCS servers) is tagged with encoder pulses and timestamps (620) for synchronization at a data aggregator node, where data from various sources is combined to calculate product quality actions at the unit level (cathode, anode, etc.).

[0039] Images of the coated substrate / material are streamed from the camera system 618 to the surface defect detection system and critical measurement and analysis system 600. The surface defect detection system is configured to analyze the image data to detect surface defects, including but not limited to edge voids, coating spots, and coating voids. Furthermore, it classifies the defects into predetermined categories and tags the data with metadata for further processing. Based on the configuration, exceptions (data containing only problems) / complete image data are stored in a designated network location (616).

[0040] The critical measurement analysis system (visual measurement system) is configured to analyze image data to detect critical measurement issues such as, but not limited to, the coating from edge to edge of the substrate, as well as the width of the coated and uncoated areas. Furthermore, it subscribes to settings, limits, and other metadata from the QCS server (614) to effectively execute the algorithm against settings, process limits, etc., from the currently selected product recipe. Based on the configuration, exceptions (data containing only problems) / complete image data are stored in a designated network location.

[0041] The aggregator node (610) is configured to sequence data based on time and encoder pulses, and to transform the data as needed. It combines data from the surface defect detection system / visual measurement system (600) and the QCS server (614). It also combines the data to detect data patterns, identify scenarios such as periodic defects and defect clusters, and flag them so that operators can easily mark / tag / comment on defective materials to take appropriate action in downstream operations. Depending on the configuration, exceptional (data with only problems) / complete data can be histated using signals to the historian server (612). Furthermore, the aggregator node 610 supplies data in a carefully designed user-friendly view for monitoring, analysis, and reporting for operator effectiveness, and calculates overall product quality actions based on the analysis of the aggregated and synchronized data. The Application Programming Interface (API) exposes the aggregated defect data and / or quality results to connected clients (602, 604, 606, 608) using an open protocol.

[0042] Figure 3 shows one embodiment of a display monitoring device 250, which includes an imaging device 252 equipped with a lens 272, a display device 254, a processor 256, and a memory 258. When monitoring the manufacturing of lithium-ion batteries, metal substrate and electrode quality measurement information is stored in the memory 258.

[0043] A suitable imaging device 252 includes digital cameras and video cameras that acquire video frame by frame. The apparatus 250 may include a ranging device 260 configured to determine the distance from the ranging device 260 to the sheet and other surfaces, and a Global Positioning System (GPS) receiver 262 configured to determine the position of the system 250. The apparatus 250 may include a sensor 264 for recognizing actions taken by the operator and a microphone 266 for acquiring voice commands or input from the operator. The processor 256 may be configured for voice recognition and gesture detection so that hand or finger gestures by the operator are identified as user commands for operating the apparatus 250.

[0044] Finally, the device 250 may include a receiver 268 for receiving data from the quality control system of the manufacturing plant and a transmitter 270 for transmitting data to the quality control system. For example, various scanners are used to measure the quality of paper during battery manufacturing. The measurements may be transmitted to the device 250 and stored in memory 258. The device 250 may also be a portable device equipped with a camera, such as a tablet or smartphone, which can be modified and programmed.

[0045] An exemplary defect map displaying the integrated quality monitoring view of the present invention is shown in the following figure. The defect map is based on the electrode manufacturing process, and the coated electrode has 250 points or bins across its width. Each bin represents a distance of approximately 5 mm.

[0046] Figure 4 shows a monitor screen 502 displaying the defect map 308 of the present invention. The program's main navigation has three functions: (1) monitoring 302, which is performed in real time and allows the operator to continuously monitor the sheet coating in progress; (2) analysis 304, which allows the operator to confirm defect insights; and (3) diagnosis / report 306. In this example, the screen shows the monitoring 302 function. The operator can switch between various monitoring systems for the defect map 308, namely (1) all defects, where the defect map view shows all defect data superimposed; (2) Web Inspection System (WIS) surface defects; (3) WIS measurement defects; and (4) Quality Control System (QCS) defects. In this example, all defects were selected. As shown in area 310 of the screen, the topcoat of the manufactured electrode was monitored for three characteristics: (1) WIS surface, (2) WIS measurement, and (3) QCS defects. Furthermore, a fourth symbol indicates overlapping defects. The legend in the defect type icon diagram indicates that each defect is represented by a specific symbol or icon. This allows operators to easily identify the types of defects appearing in the defect map.

[0047] The defect map 312 includes 12 columns or strips representing different parts of the electrode sheet being monitored. The first column on the left represents the most recently manufactured coated sheet, with the vertical length corresponding to the machine direction (MD) of the sheet and the width corresponding to the transverse direction (CD). Defects are mapped across the columns. In this example, column 2 shows a significant number of defects of all three types. The location of each defect can be identified by its MD and CD positions. As is evident, many of the defects appear at the edges of the sheet. Column 4 shows several overlapping defects.

[0048] When the operator hovers the cursor over a specific icon, the program provides information 314 consisting of the MD and CD locations of the defect, the specific defect type, and the scanner or camera that detected the defect. In this example, area 316 of the monitor screen shows the status of six cameras and six scanners. In this case, camera 3 and scanner 3 are inactive. The program of the present invention features various on-screen actions, including: (1) a pause button 318 that allows the operator to stop production and take immediate action in the event of a major problem; (2) a zoom function 320 that enlarges the view of the area; (3) a history detail display function 322; (4) a detail display function 324; and (5) a filter display function 326.

[0049] Figure 5 shows the monitor screen 504 when the detailed display 324 option is selected. The side panel is open, containing basic details of the roll, namely (1) total number of defects, (2) number of defects on the coating side, (3) roll details, and (4) threshold.

[0050] Figure 6 shows the monitor screen 506 when the filter 326 option is selected. The side panel, which includes basic and more advanced filter options, is open. The operator can select multiple scanners and / or cameras, as shown in Figure 7. In the defect category, the operator can filter defects by frequency of occurrence, whether periodic or aperiodic, and can also flag defects. The operator can manually flag areas, or the system can automatically flag areas based on defect density. The defect map in Figure 6 shows only the result when only the upper scanner and upper camera are selected in the panel.

[0051] Figure 7 shows the monitor screen 508 when the filter 326 option is selected. The operator selects multiple views by selecting cameras and scanners at different angles, including scanners and cameras facing the bottom coat on the electrodes. As a result, bottom coat defects are added when the operator selects scanners and cameras facing the bottom coat. The legend shows icons related to the bottom coat. As shown in the defect map, this includes bottom coat defects superimposed on the same electrodes as the top coat electrodes.

[0052] Figure 8 shows the monitor screen 510 when an operator attempts to review details about a particular defect. The program allows the operator to click on a defect or area of ​​defects to view details about the defect / cluster of defects. In this example, the operator clicked on an individual defect 330 located at strip number 7. A side panel opens containing first-level details about the selected defect. This panel is divided into three sections: (1) defect image, (2) color map, and (3) flag details. As shown in Figure 9, activating the first tab, defect image, generates the exact location, size, outliers, and other details of the defect. It also displays an actual image of the defect. The second tab is for accessing the QCS color map (which is further explained in Figure 11), allowing the operator to compare the defect map with the color map to obtain information about how the variability occurred. The third tab activates the defect flagging option, which allows the operator to quickly flag individual defects or areas of interest for later review during the analysis phase. Automatic and manual alarms or flagging can be implemented in this invention. If a critical defect exists on the sheet, the system can be configured to automatically identify the problem and flag the area.

[0053] Figure 9 shows the monitor screen 512 when an operator reviews a region of defects on a strip. In this example, region 340 within strip 7 is selected. Similar details are shown for clusters of defects with minor changes. Instead of individual defect details, the operator can view a list of defects with their location and image / video links. QCS colormap and flagging options are also available. When flagged defect features are selected, identifiers are displayed on the y-axis, allowing for easy access to these regions. Furthermore, the operator can select a filter for flagged defect modes to view all regions that have been flagged manually by the operator or automatically by the system.

[0054] Figure 10 shows the monitor screen 514 when the operator attempts to investigate details about a particular defect within region 360 on strip 7. In this example, the color map option is selected, and the operator can see a + / - 10 scan of the color map on the monitor screen, which shows the trend of variation.

[0055] Figure 11 shows the monitor screen 516 when the operator is focused on monitoring surface defects. The WIS surface defect option is selected. The type of surface defect depends on the sheet material being manufactured. Examples of surface defects include holes, craters, and bubbles. As shown in the legend area 370 of the screen, for electrode manufacturing, surface defects in the electrode top coat and bottom coat include coating voids, coating spots, edge voids, and thin spots. For both the top coat and bottom coat, an icon is shown for each of these defects. In addition, another icon identifies overlapping defects. Surface defects are plotted and shown on the defect map.

[0056] Figure 12 shows the monitor screen 518 when the operator wants to focus on measurement and monitoring edge defects. The WIS measurement defect option is selected. The program provides a detailed view of measurement defects or edge defects that measure the variation on the edge of the sheet. As shown in the legend area 380 of the screen, for electrode manufacturing, measurement and edge defects of the electrode top coat and bottom coat include starting point deviation, coating spots, edge voids and thin spots. For both the top coat and bottom coat, an icon is shown for each of these defects. In addition, another icon identifies overlapping defects. Surface defects are plotted and shown on the defect map.

[0057] Figure 13 shows the monitor screen 520 when the operator focuses on QCS defects and the QCS defect option is selected. The type of QCS defect depends on the sheet material being manufactured. Surface defects include, for example, basis weight and thickness deviations. As shown in the legend area 390 of the screen, for electrode manufacturing, the monitored QCS defects of the electrode top coat and bottom coat include basis weight deviations classified as high-high, high, low-low, and low. For both the top coat and bottom coat, an icon is shown for each of these defects. In addition, another icon identifies overlapping defects. Basis weight defects are plotted and shown on the defect map.

[0058] Figure 14 shows the monitor screen 522 when the program is running with an analysis function covering all 400 defects. The operator can view the historical data on the sheet. The analysis screen features the same navigation options described above to allow the user to easily select items. In addition, there is a strip-level filter that provides a higher-order view of the health of each strip. As shown in area 400, the strip-level filter shows each strip number 1-12 and the number of defects within each strip. In this example, a total of 45 defects are shown across all 12 strips. There is a zoom function 412 to enlarge the graph. The bar graph shows the number of defects in each bin. The operator can use the selection list 414 to select a bin for additional detail. In this example, the operator selected bin 81. As shown in area 410, a total of 65 defects are shown within bin 81. The detailed bin view on the right shows the defect size distribution over the length of the electrode in bin 81. The size of the defects is taken up on the x-axis. Note that while the total number of defects in strips 1-12 is 45, the total number of defects across all bins is much larger. The reason is that the historical data covers not only strips 1-12, but also other older bins.

[0059] Figure 15 shows the monitor screen 524 when the program is running with an analysis function that covers all defects. The operator has chosen to receive information on the effect of a certain variable on the number of defects. Graph 420 shows the number of defects versus coating rate. Graph 422 shows the number of defects versus ambient temperature. Graph 424 shows the number of defects versus oven temperature 1, and graph 426 shows the number of defects versus oven temperature 2.

[0060] Figure 16 shows the monitor screen 526 when the program is running with a reporting function that covers all defects. It shows the breakdown of the number of defects versus six different types of defects in strips 1-12, for top coat vs. bottom coat. It shows the breakdown of periodic defects versus aperiodic defects. It shows the breakdown of clustered defects versus non-clustered defects. It shows the defect density by number of defects versus length in strips 1-12, for top coat vs. bottom coat.

[0061] The above has described the principles, preferred embodiments, and operating modes of the present invention. However, the present invention should not be construed as being limited to the specific embodiments considered. Therefore, the embodiments described above should be considered illustrative rather than restrictive, and it should be understood that those skilled in the art can modify those embodiments without departing from the scope of the present invention as defined by the following claims.

Claims

1. A method for estimating the quality of a sheet roll, A visual defect tracking system comprising at least one imaging device configured to image the surface of the sheet roll is used to monitor surface defects in the sheet roll, Monitoring for measurement defects in the sheet roll using a visual measurement system comprising at least one scanner configured to measure the basis weight and thickness of the sheet roll, The quality defects of the sheet roll are monitored using a quality control system configured to analyze data received from the at least one imaging device and the at least one scanner. The marker device provides at least one reference marker to the sheet roll at predetermined length intervals along the machine direction, wherein the at least one reference marker synchronizes defect measurement across the visual defect tracking system, the visual measurement system, and the quality control system. The processor generates a defect map that visually represents and correlates the surface defect, measurement defect, and quality defect data obtained from the at least one imaging device, the at least one scanner, and the quality control system. A method that includes this.

2. The method according to claim 1, wherein monitoring of the surface defects, measurement defects, and quality defects is continuous.

3. The method according to claim 1, wherein the monitoring of the surface defects, measurement defects, and quality defects is in real time.

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