Active torsional vibration damper

A method of damping resonance torsional vibrations in a system having a member capable of transmitting a torque, the method comprising the steps of:

• detecting a resonance torsional vibration in the member;
• periodically estimating a time period when the resonance torsional vibration is between peak angular amplitudes at a damping location:
• periodically imparting torsional impulses to the member at said damping location over a portion of said time period in a direction opposite to a twisting motion from the resonance torsional vibration;
• wherein said torsional impulses have sufficient energy to damp the resonance torsional vibration such that said peak angular amplitudes are maintained less than a threshold amplitude:
• wherein said detecting step includes the steps of:
• measuring a magnitude of the resonance torsional vibration for at least one location along the member;
• determining whether said magnitude exceeds a minimum threshold value;
• wherein said estimating step includes the steps of:
• identifying what operating conditions of the system excite resonance torsional vibrations;
• measuring a frequency of the resonance torsional vibration at each of said operating conditions;
• storing a frequency measurement for each of said operating conditions;
• and
• sensing an operating condition of the system when the resonance torsional vibration is detected.

A method of damping resonance torsional vibrations in a system having a member capable of transmitting a torque, the method comprising the steps of:

• detecting a resonance torsional vibration in the member;
• periodically estimating a time period when the resonance torsional vibration is between peak angular amplitudes at a damping location:
• periodically imparting torsional impulses to the member at said damping location over a portion of said time period in a direction opposite to a twisting motion from the resonance torsional vibration;
• wherein said torsional impulses have sufficient energy to damp the resonance torsional vibration such that said peak angular amplitudes are maintained less than a threshold amplitude;
• and
• wherein said imparting step is performed at a frequency about equal to the frequency of the detected resonance torsional vibration.