Assembly In Action: Machine Vision Ensures Quality
July 23, 2008
Keiper GmbH & Co. (Kaiserslautern, Germany) manufactures metal seating components for the automotive industry. Its customers include Volkswagen, KIA, Lear, Land Rover and Ford, just to name a few.
Historically, the company used a complex mechanical control system equipped with a number of touch controls to perform part presence and variant inspections of the components making up its seat adjustors. However, this system left much to be desired in terms of flexibility and reliability.
To remedy the situation, the company recently implemented a vision inspection cell employing an In-Sight 5403 vision sensor from Cognex Corp. (Natick, MA). The system is now used to identify approximately 20 different parts-some of them with very subtle differences in shape and features. Because of its increased reliability and ease of use, the system paid for itself in less than a year.
In inspecting and differentiating the many parts that pass by, the In-Sight 5403 not only inspects each part for defects, but checks to see that each part is correctly positioned in its fixture. In doing so, the camera needs to accommodate the fact that the parts will sometimes vary in color depending on the supplier. It also needs to contend with the fact that the parts sometimes have an oily film on their surface, and some of the parts are pitch-black while others have a metallic sheen.
In operation, the sensor employs PatMax identification software to pinpoint important characteristics such as edges, dimensions, angles, arcs and shaded areas. This, in turn, allows the system to detect those instances when a wrong part is going into an assembly.
For example, in many cases the differences between the parts going onto the left or right side of a seat are so small as to be easily missed by the operator loading them onto a fixture. However, the vision inspection system now immediately recognizes whenever that happens and notifies the operator that the part needs to be changed. This allows the error to be corrected without interfering with overall production flow and before it results in a defective assembly.
After installing a first inspection station, Keiper went on to install a second station about a year later. According to Keiper engineer Markus Roder, the two systems fit easily into the company’s overall production line and have been easy to both program and maintain. “Employing a reliable international vision supplier like Cognex offers benefits which have a long-term impact on the entire group and its international production network,” Roder says.
For more on machine vision and inspection, call 508-650-3000 or visit www.cognex.com.