BYD is the largest manufacturer of mobile phone batteries in the world. During production, a series of defects could occur during the assembly and the handling of the battery belts, such as 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 this continuous inspection process. It is clear that vision technology was the only choice to solve this problem.
Powerful capabilities and technical support
Due to the high speed and integration 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 extremely small smart cameras that could handle high speeds and had powerful inspection tools. For these reasons, Cognex products were the right choice.
Cognex is machine vision expert. The In-Sight® micro is the smallest smart camera in the world but features the most powerful capabilities. Currently, there are 16 production lines and 64 cameras in operation in the company. The accuracy of testing has reached 99%, but that wasn’t good enough to meet quality targets.
High in resolution and fast in speed, Cognex In-Sight Explorer 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. 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. 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, providing instant 100% inspection without the possibility of missing a defect. When the system detects any issues with quality, it will send a signal to the motion system, which will pick out and reject the defective products. The images related to all the errors can be stored and viewed for further analysis.
BYD’s own development team was able to integrate the products from Cognex into the production lines after a small amount of initial technical instruction.
Customer satisfaction for future deployments
By using the high performance of the In-Sight Micro to inspect all products, BYD can eliminate product defects and improve the quality, while recovering the investment in just one year.
The senior engineer Huang of BYD said, "The products from Cognex are powerful and stable. According to the conservative estimates, there now have 300 sets of Cognex products in operation. After years of application and exploration, Cognex products guarantee an improvement in the quality of our own products. Furthermore, when we introduced our equipment to Nokia and Motorola and other VIP clients, they are always interested to see that we use Cognex vision products and thus are more confident about our equipment, which is then backed up by the actual product quality.”