Web tension control of a start-up process using observer techniques with friction and inertia compensation

System friction or rotational roll inertia can cause a problem in estimation of web tension if the process speed and/or its variation are high. Very few literatures have considered both problems in a single article. This paper presents observer-based feedback controllers with friction and inertia compensation to control web tension during system start up. Observer techniques play a dominant role to assure precise estimation of web tension. The proposed observers have a feedback configuration that is also robust against system parameter variations. Simulation and experiment have shown that the proposed controllers without a tension measurement perform well against the friction and inertia disturbances. Observer-based tension feedback control can perform equivalently as well as classical feedback control does using a load-cell transducer.