The adaptive feedforward control technology, which is implemented in the stretch reducing process of seamless pipe wall thickness at Baosteel Tubing Plant, is introduced.

As the adaptive feedforward control method used for active control of periodic vibration has many shortcomings, an adaptive feedback control method was proposed based on on-line frequency estimation.

The research shows that the active noise controls adopted feedforward technology or feedback technology is correspond to adaptive control with measurable noise or immeasurable noise.