Design and implementation of active dynamic vinration absorber for broadband control

Abstract

Dynamic Vibration Absorbers (DV A) are passive devices that attenuate vibration at a single resonance frequency. However, to use the DVA for the reduction of vibration in multi degrees of freedom (MDOF) systems which have more than one resonance frequency requires modification of the DV A. These modifications are accomplished by using active control strategy on the DV A. This transforms the DV A into an Active Dynamic Vibration Absorber (ADVA). Various actuator systems have been used for the transformations of DV A into ADV A. These include Proof Mass Actuators (PMA), Piezoelectric Absorbers and Smart spring Absorbers. Limitations in the ADVA design and their control strategy which always affect their performance include friction force, energy requirement and complexity of design. In this research, a less complex design of an Active Dynamic Vibration Absorber (ADV A) and its controller is proposed. The ADVA adaptively tunes to attenuate vibration of the broadband resonance frequencies of MDOF system with minimum limitations. This study includes the mathematical modeling and experimental verifications of the resonance frequencies of the three degrees of freedom (3DOF) system on which the ADV A was implemented. Based on the broadband resonance frequencies of the 3DOF system, a prototype ADV A has been developed. The ADV A uses a proportional-integral-derivative {PID) controller to change its stiftb.ess adaptively to reduce vibration. The optimal location of the ADV A on the MDOF system was also identified. Experimental results show that the ADVA was able to reduce the vibration of the MDOF system at all the modes. Due to the properties of the ADVA spring material used in this study, vibration attenuation at the first mode was limited to SdB. For further research, a spring material with a lower modulus of rigidity is suggested to improve the performance of the ADV A.