摘要 |
A rotary knife (10) incorporates the use of an electronically controlled, active damping system (16, 18) to control vibrations of knife cylinders. The system preferably uses pairs of electromagnetic actuators (106, 108) to provide opposing pulling forces on a ferromagnetic portion of a lever arm (90) that is mechanically coupled to the stationary support shaft (22) for the knife cylinder. Vibration sensors, preferably accelerometers (96, 98), are used to monitor vibrations of the respective knife cylinders. A digital signal processor (100) implementing a state space control system controls the electromagnetic actuators to actively cancel vibration energy in the knife cylinders. |