Feed forward thickness control compensates for any as the thickness deviations in the entering strip. 

Therefore, the strip thickness is measured at the entry side of the mill using a thickness gauge. 

The measurement is stored in a buffer and tracked according to the strip speed to the roll gap. 

Then the roll gap is opened or closed in order to com-pensate for the strip entry thickness error. The time the measurements remains in the buffer depends on the strip en-try speed, the response time of the thickness gauge and the response time of the hydraulic roll gap adjustment. 

The strip entry thickness error is measured before forming of the material takes place. Therefore the feed forward thickness control (due to its structure) can compensate for any entering thickness errors with a very high dynamic.

 For feed forward thickness control a proportional (P) controller is applied. The feed forward thickness control calculates offsets to the position control taking the strip width dependent mill modulus and the material modulus into account.