COMPLETE PROCESS VISION IMPROVES PRODUCT QUALITY AND PROCESS EFFICIENCY WITH RAPID ROI

COMPLETE PROCESS VISION IMPROVES PRODUCT QUALITY AND PROCESS EFFICIENCY WITH RAPID ROI

Goal: maximize product quality and yield, and reduce production costs.

not only improves operator safety, it also frees employees from tedious tasks.

Today’s leading aluminum suppliers strive to continuously improve their rolling processes to maximise product quality and yield, and to minimise production costs. For example, in the extremely competitive aluminum can business, producers seek to obtain the highest level of quality at the lowest price. For this reason, any technology that enables a supplier to produce the desired product with greater efficiency and yield—in other words at a lower cost would be highly desirable. With lower production costs, suppliers can achieve greater flexibility by balancing their sales price and sales volume to stay competitive.

Even incremental improvements in process efficiency and yield can markedly impact profitability.

Detecting and identifying defects prior to value-added downstream processes is one important way to reduce cost and ensure product quality. Ideally, the line supervisor would like to quickly identify where a defect originated within the process, or determine if the defect was actually created in a prior process. When production line problems are solved rapidly, downtime and scrap are minimised, and yield is maximised.

In many situations, new worker safety requirements and machine guarding prevent operators from manually inspecting the strip while the line is in operation. As such, another way to reduce cost is to address the inspection challenges created when employees are physically isolated from machines.

Enhancing manual inspection processes with vision technologies

Aluminum manufacturers also seek new aluminum applications.

One such opportunity is the substitution of steel with specialized or premium quality aluminum to enable manufacture of lighter weight vehicles. For this application, end users require a more optically uniform, defect-free strip. To produce such a strip often requires next-generation inspection techniques.

Though surface inspection systems are commonly used to examine metal strip, there is a critical need for advanced vision technologies that can pinpoint the exact location of an upstream process problem with greater speed and accuracy. Of course, any new vision technology chosen to address these trends is expected to produce a rapid return on investment (ROI).

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SURFACE INSPECTION

Current approach To achieve these goals, many aluminum suppliers have adopted surface inspection systems. These vision systems routinely and reliably detect surface defects and irregularities using various camera and lighting configurations including collimated, diffuse, or side lighting depending on the application. With collimated light, two sets of cameras capture the material surface from different angles thus enhancing defect detection. In real time, experienced operators can use the resulting images to aid in troubleshooting line problems.

Engineering and quality departments aggregate and analyze the defect information in support of their longer term-process improvement

recommendations and decisionmaking. Customer service and order fulfillment departments often use the information to grade, allocate and price the product to the appropriate use and end-user.

Advanced systems, such as SmartView® Metals with patented SmartLearn® Multi-Step Classifier, automatically classify defects and irregularities to give the operator more insight about the overall quality of the coil. However, even when using advanced systems, confirming the “why and where” of the problem can be a timeconsuming and imprecise task.

When small defects occur in a very large strip, finding the source of the problem can be as difficult as “finding a needle in a haystack.”

As a result, these defects can shut down a production process for hours. Though millions of miles of metal strip have been successfully examined by surface inspection systems, there remains a need to automatically, and thus more rapidly, pinpoint the exact location of an upstream process problem.

A better solution: complete process monitoring speeds problem resolution The solution to the problem lies in the integration of high-resolution surface inspection at the line exit, with video cameras that are synchronized and strategicallyplaced throughout the line. To create this solution, software (SmartSync) is used to link highresolution surface inspection (SmartView) and web-based monitoring (SmartAdvisor™).

The combination of capabilities produces a comprehensive view of the entire rolling process in which the visual synthesis of upstream and downstream events captured on video enable the

Fig. The integrated combination of surface inspection and process monitoring platforms provides a comprehensive view of the complete process. operator to rapidly determine the root cause of defects and take immediate corrective action. With the combined solution, process problems are resolved more rapidly enabling the supplier to minimize if not eliminate defects, and to increase yield and efficiency.

Though this combined solution is new to the metals industry, it is based on proven technology leveraged from other continuousstrip applications where hundreds of similar systems are installed worldwide. The technology has been specifically adapted to metals, using early-adopter feedback from the world’s largest aluminum manufacturers.

The SmartAdvisor process monitoring system uses a series of cameras to monitor multiple user specified points along a production line simultaneously.

Patented line-synchronization technology integrates all the images together into one fullyvisualized process flow. Because the cameras are automatically synchronized to continuous metal processing, it tracks and pinpoints

where a defect or problem in the process occurred, from root cause to failure, more accurately and efficiently than single-point surface inspection. Operators are also able to determine if the defect originated in the current process or if the defect was already present in the raw material. Its cameras can be configured to focus very closely on the strip, or further away to capture the overall work environment.

The flexible front-end of the design ensures that the complete rolling process from entry to exit can be scaled up to provide synchronized vision and process control across the entire production line. Critical defects and process upsets automatically trigger a video of the defect on the strip as it passes each camera’s vantage point. The SmartSync software combines video and defect classification information into an integrated composite quality map.

Its database allows reporting of all visual anomalies.

The SmartAdvisor system can also function as a standalone inspection and diagnostic tool.

Aluminum suppliers currently use its video and defect detection information to inspect the bottomside of their slabs. Because it is portable, the solution can be used to troubleshoot almost any process including slitters and cut-to-length lines. Repeating defect detection algorithms have been specifically designed to find defects such as roll marks.

Results obtained Using this technology, aluminum processors are already increasing their quality and yield, and reducing unscheduled downtime.

Time is no longer wasted troubleshooting or performing maintenance on the wrong machine or the wrong process.

By eliminating manual inspection and other costs such as material handling and unnecessarily scrapping good material, they are also realizing substantial cost savings.

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For one of the industry’s largest aluminum suppliers, the cost savings realized surpassed the cost of their system --$100,000 US-- in less than one month. This rapid ROI was achieved due to a marked improvement in the supplier’s ability to:

Real-time and historic video from each process monitoring camera

• Track down the root-cause or origin of defects by “rewinding” images from each location on the line.

• Determine whether a defect originated from an upstream line, for example the hot strip mill or occurred on the current line, the cold mill.

• Immediately identify and confirm welding defects before they became much larger, more costly problems downstream.

Though these results are quite remarkable, with the cost savings achieved, users can expect a typical system to pay for itself in nine months or less.

Jason Zyglis, Strategic Marketing Manager, COGNEX Corporation

A repeating defect classified at the rolling mill exit was also seen as it entered the rolling mill.

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SURFACE INSPECTION