Method for reducing the effects of parent roll variations during unwinding

A method for reducing the effects of variations in unwinding a convolutely wound roll of web material, said unwinding being modifiable by an actuator, the method comprising:

• a) providing an out-of-round convolutely wound roll of web material and selecting a reference objective relating to a downstream operation;
• b) choosing at least one feedback device correlated to said reference objective;
• c) collecting process data from said at least one feedback device at different positions within a time-varying operation cycle for at least one operation cycle comprising one revolution of said convolutely wound roll of web material to detect at least one periodic disturbance beginning at a first position within said time-varying operation cycle selected from the group consisting of feed-rate variability, web velocity variability, tension variability, and combinations thereof in the convolutely wound roll at a learning speed;
• d) calculating an error as the difference between said collected process data from step (c) and a reference signal related to said selected reference objective;
• e) generating a correction signal based upon said calculated error from step (d);
• and,
• f) applying said correction signal to said actuator beginning at said first position during a succeeding time-varying operation cycle.