In-Sight enhances phone-battery inspection at BYD

BYD has used Cognex In-Sight 1403 vision systems to improve quality-control during production of mobile-phone batteries.

Possible defects that can occur during the assembly and handling of the battery belts include surface tearing, scratches and tab breaks, all of which decrease the battery capacity and cause leakage.

The surfaces should therefore be inspected before further production and, to avoid damaging the surface, there should be no direct contact with the battery belt during inspection.

Vision technology was therefore the only solution.

Due to the high speed of the production lines, each line needed four cameras, auxiliary light sources and assembly parts to test the surface quality of both sides of the positive and negative poles of the battery belt.

The application required small cameras that could handle high speeds - so BYD turned to Cognex.

Cognex's In-Sight 1403 is as small as an egg but has powerful capabilities.

There are currently 16 production lines and 64 cameras in operation in the company and the accuracy of testing has reached 99 per cent.

High in resolution and speed, Cognex software features a powerful blob-analysis tool and easy and flexible software setup.

The solid and durable camera housing provides a high level of protection.

Cognex also offers quick solutions and superior technical support.

In this application, the vision system operates continuously, with a vision field up to 10*8cm and processing ability of two frames per second, none of them identical.

From image three to image six, each shows the number of photos and the type of test to be processed by the cameras.

As it appears in the field of view, each camera judges between two and four types of image.

Because of the different nature of the photos, the corresponding test methods and parameters are different.

This means four cameras will run approximately 12 sets of programs to inspect the product's parameters, looking for flaws, scratches, loss of material, turn ups, length of the tab, position of the tab, holes in the aluminium foil, position of the rubberised fabric, extra length on both sides and so on.

Mistakes can be easily made when only judging the size and brightness of the parts.

The software also adds enhanced analysis of the contrast of the defect, the proportion of bright to dark pixels and the total number of pixels.

This provides for greater focus and improves the accuracy of the inspection by fourfold.

For each battery belt, the integrated processing results of multiple photos are sent to the motion-control system to reject the products that fall below the predetermined thresholds.

This system is integrated into the operation equipment, providing instant 100 per cent inspection without the possibility of missing a defect.

And the speed of detection meets production requirements.

When the system detects any issues with quality, it sends a signal to the motion system, which picks out and rejects the defective products.

The images related to all the errors can be stored and viewed for further analysis.

The system allows the setup of man-machine interaction parameters and the authority to modify them through a convenient user interface.

The system also has a self-learning function that provides a simple training process.

BYD's own development team integrated the Cognex products into the production lines after a small amount of initial technical instruction.

Only BYD knew its machinery well enough to develop the application in-house.

By using the high-performance In-Sight 1403 to inspect all products, BYD can eliminate product defects and improve the quality, which decreases the rejection ratio in the follow-up processes and helps to recover the investment in just one year.

Inspired by the success from the In-Sight 1403, the engineers of BYD will continuously use its products in other production fields or production lines.

Cognex provides software, hardware and after-sales services.

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