The following article describes a method developed to control the ultrasonic fuel rail welding. It is done monitoring some physical phenomena during the process, like vibration amplitude, welding energy and its duration.
Based on statistical analysis, durability and aging tests on a great population of manufactured parts, it was possible to classify those parameters and build a real time filter capable to segregate bad parts in less than one second, just after process is done. This way, it is possible to purge the bad parts before spending more time and resources in a nonconforming segment.