I have an application where I do unrolling of a bobbin.
It is a central unwinder (axis of the bobbin is driven).
We have no diameter measurement.
The starting diameter of the bobbin can be very small to very big.
There is a balancer after the unwinder.
We setup a linespeed that the unwinder has to follow.
When starting, there is a rather long acceleration time, allowing all getting sychronised well (balancers must stay approximately in the middle).
For now the unwinder gets a speed setpoint proportional to the line speed.
There is also an addition of a PI controller concerning the balancer of the unwinder. The integral factor shall make up for the variation in diameter.
During acceleration a rather big integral factor is used, when at speed the integral factor is reduced.
But we keep having troubles unwinding the large bobins.
Now I was thinking of when accelerating from start, first go to low speed, then waiting until the balancer is stable, and then calculate myself the diameter of the roll based on the actual unwinderspeed and the actual linespeed.
Is this also a procedure that some of you would follow if no actual diameter measurement can be placed?
It is a central unwinder (axis of the bobbin is driven).
We have no diameter measurement.
The starting diameter of the bobbin can be very small to very big.
There is a balancer after the unwinder.
We setup a linespeed that the unwinder has to follow.
When starting, there is a rather long acceleration time, allowing all getting sychronised well (balancers must stay approximately in the middle).
For now the unwinder gets a speed setpoint proportional to the line speed.
There is also an addition of a PI controller concerning the balancer of the unwinder. The integral factor shall make up for the variation in diameter.
During acceleration a rather big integral factor is used, when at speed the integral factor is reduced.
But we keep having troubles unwinding the large bobins.
Now I was thinking of when accelerating from start, first go to low speed, then waiting until the balancer is stable, and then calculate myself the diameter of the roll based on the actual unwinderspeed and the actual linespeed.
Is this also a procedure that some of you would follow if no actual diameter measurement can be placed?