Active Stabilization of a Hybrid Vibration Absorber Subjected to Velocity Feedback Control

A method of actively stabilizing a hybrid vibration absorber driven by a force proportional to the velocity detected at the attachment position of the absorber is investigated. This method can be applied to improve model-independence of robust performance while allowing for multimode controllability for the case where a hybrid vibration absorber is desired as an actuator. Robustness not only against variations in a primary structure to be controlled but also against parameter identification errors in a vibration absorber system is discussed. It is illustrated that although this method transforms the hybrid absorber equation with a spring term into the full active absorber equation, the important advantage of a hybrid absorber over a full active absorber, that is, the power-saving effect near the first resonant frequency of a primary structure can be retained. Application examples are presented also for the vibration isolation and active noise control problems.