Active structural cloaking using equivalent feedback cancellation

A novel concept of active structural cloaking based on equivalent feedback cancellation is proposed for coupled vibratory systems. The cloaking strategy is demonstrated on the simplest case of a two degree-of-freedom (2DOF) lumped parameter system composed of a main (primary) structure and an attached (secondary) structure. The target output of the coupled system corresponds to the response of the primary mass in the absence of the attached structure. The equations of motion for the 2DOF system are presented, from which a velocity feedback control law for structural cloaking is identified. With feedback cancellation, the primary mass is effectively decoupled from the secondary mass. New resonances for each mass are observed. The active structural cloaking approach is shown to be stable.