Method and control system for tuning flatness control in a mill

A method for tuning flatness control for rolling a strip in a mill including rolls controllable by means of a plurality of actuators, which mill is modeled by means of a mill matrix. The method includes: a) obtaining an equivalent movement range for each actuator, b) determining a scaled mill matrix by scaling the mill matrix based on the equivalent movement ranges, and c) obtaining a singular value decomposition of the scaled mill matrix for providing flatness control of the strip by means of the actuators. A computer program and a control system for carrying out the above method are also presented herein.