Structural vibration control using an active resonator absorber: modeling and controlimplementation

Abstract

A new dynamic vibration absorber referred to as an active resonator absorber (ARA) isproposed; we explore its practical implementation using piezoelectric ceramic (PZT)inertial actuators. The ARA is a passive absorber with an additional dynamic feedbackcompensator within the PZT actuator. Without any controller, it becomes a passivevibration absorber due to internal damping and elasticity properties of the piezoelectricmaterials; hence, it is inherently fail-safe. For active operation, the compensatorparameters are designed such that a resonance condition is intentionally createdwithin the absorber subsection to mimic the vibratory energy from the system ofconcern to which it is attached. The resonance condition can be created through theappropriate design of the compensator and implemented through adjusting theexternal electrical voltage applied to the PZT actuator. Although PZT materialsinherently possess nonlinear characteristics (e.g., hysteresis), an equivalent linearizedmodel is developed for the actuator subsystem. An experimental set-up is thenconstructed to validate the proposed linearized model and estimate the actuatorparameters using a nonlinear least squares algorithm. Because the parameters of thePZT actuators (i.e. stiffness, damping, and effective mass) are approximate, thecompensator designs based on these parameters would result in partial vibrationsuppression when utilized in real applications. An auto-tuning method is used toeffectively tune the compensator parameters to improve the vibration suppressionquality. The effectiveness and stability of the proposed auto-tuning scheme whenimplemented on a single-degree-of-freedom primary system are demonstrated.