Established in 1933, NISSAN Motor Corporation is the second largest auto company and one of the three largest automobile manufacturers in Japan, the top 10 automobile company in the world, as well as the first manufacturer to produce small-sized Datsun sedan and auto parts and components. In addition to producing automobiles, the company, as a huge multinational group company also sets foot in machine tool, engineering machinery, shipbuilding and astronautical technology areas. The headquarters of NISSAN is now located in Tokyo of Japan, with a total number of approximately one hundred and thirty thousand employees. The auto products by NISSAN can be divided into practical sedan (i.e., truck, mini pickup and four-wheeled truck), luxurious limousine and ordinary sedan.
Nissan has always put strict requirements on product quality, and constantly strives to improve the production process in itself, aspiring to reach the goal of end product "zero defects", so that consumers, driving a Nissan car on the road, get absolute satisfaction. Automobile engine assembly line adopts vision system in error prevention and identification, making the automobile industry progress toward zero defect goals.
During installing piston at engine assembly line, two piston rings of different models are required for each engine piston. Insight5100C can distinguish and identify the piston rings at different locations and of different colors through visual tools.
The vision system needs to recognize and differentiate the missing, wrong type and reverse attachment of piston ring by color marked on the piston ring, and send the results to PLC via ProfiNet protocol.
Detect missing attachment of piston ring
Determine the grey value at O ring with histogram. Since the histogram value difference is significant with or without attachment, the issue can be detected by mean grey value at O ring.
Determine whether piston is at the tray by Pattern
Color of piston ring correct or not
To extract the color at O ring by using the most recent color extraction tool ExtractColor (supported by later version than In-Sight Explorer 4.3.0) of Cognex, and then to judge whether the color matches with the specified color;
Piston ring attachment reverse or not
First extract color at O ring with ExtracColor, then find color Blob with ExtractBlob based on the image output by ExtractColor function. Taking color Blob as positioning reference, determine average grey value with histogram and find gap at right of the color. Grey value at the gap and the ring
Ensure to provide zero missing judgment for the customer
Before that, the engine assembly line of customers are semi-automatic, and detection of piston rings has always been dependent on human eye for judgment, however, people will get distracted and fatigue, which results in incorrect, missing and reverse attachment and other quality accident. Color tool of IS5100C solves this problem excellently, improving quality and lowering labor costs.