In the world of Roll forming, length control discussions usually come down to, “Do we run an open loop or a closed loop system?” In some cases, both types of length control might be used on the same production line. Above, you can see two animated versions of the concepts depicted in examples of a flying die application, but both types are also available for feed-to-stop applications, as well.
Open or Closed?
For the most part, when someone talks about Open or Closed Loop, they are specifically denoting the presence of a servo system. The servo system is looking for a command to tell it what speed, direction, and position go to on a millisecond-by-millisecond basis. In this context, the controller tells the servo go here and the servo responds with feedback I’m there. Continue reading “Closed Loop vs Open Loop”