Kataeb
Member
Hy sirs, we have the following special application:
A web is passing through a dancer which is mounted on two linear bearings.
One unwind motor is used to control the position of the dancer (keep it in the middle) by changing the web unwinding speed.
Also a servomotor, which is mechanically linked to the dancer, should provide a constant force on the dancer (constant tension on the web) by moving the dancer forward or backward, the actual force is measured by a load cell.
The web is subject to fluctuations (tension variation) from the main machine and for other reasons. After checking the linear bearings characteristic, we found that it has a variable friction coefficient which depends on many things (status of the parts, greasing, aging,…).
So this made our task very difficult. Any ideas on how the servomotor should react to compensate the frictions and provide a constant force on the dancer?
Appreciate your help.
Thank you
A web is passing through a dancer which is mounted on two linear bearings.
One unwind motor is used to control the position of the dancer (keep it in the middle) by changing the web unwinding speed.
Also a servomotor, which is mechanically linked to the dancer, should provide a constant force on the dancer (constant tension on the web) by moving the dancer forward or backward, the actual force is measured by a load cell.
The web is subject to fluctuations (tension variation) from the main machine and for other reasons. After checking the linear bearings characteristic, we found that it has a variable friction coefficient which depends on many things (status of the parts, greasing, aging,…).
So this made our task very difficult. Any ideas on how the servomotor should react to compensate the frictions and provide a constant force on the dancer?
Appreciate your help.
Thank you