A passive and semiactive vibration absorption scheme for a mechanical system subject to harmonic excitations is developed in this study. The passive attenuation of the main system is obtained using a flexible inverted pendulum vibration absorber (FIPVA) which is designed to attenuate the vibrations affecting a certain vibration mode exactly or close to some specific resonance frequency. In order to improve the overall system performance against possible variations on the excitation frequency or parameter uncertainty, a PZT patch actuator is cemented to the base of the FIPVA and, therefore, the vibration absorber proposed can be automatically tuned, by means of the application of a suitable control law employing feedforward information from the excitation force as well as position feedback of the secondary system. Numerical simulations and experimental results, using a Stewart platform as exciter, are included to show the dynamic behavior of the complete system, resulting in good attenuation properties.
