Active Vibration Control: Two Different Experimental Approaches

This paper proposes two methods for active suppression of mechanical vibrations in thin-walled structures using Positive Position Feedback (PPF) and Particle Swarm Optimization (PSO) algorithms. The proposed method involves the estimation of participation matrices using experimental measurements only, eliminating the need for an electromechanical model. A bidimensional composite plate with free edges and eight vibration modes was used to test the proposed method. Four sensors and four non-collocated actuators were used to suppress vibrations, resulting in a reduction of several decibels in the amplitude of all eight modes, with negligible spillover. On the second methos proposed, the PSO algorithm was employed to tune the MIMO PPF controller to minimize the time necessary for free vibrations to decay to zero or to minimize the area under the resonance peaks of the frequency response. The parameters determined by the PSO algorithm were verified through simulations based on a reduced-order model and laboratory experiments. The vibration reductions achieved experimentally were up to 90% of the uncontrolled amplitude for the first eight modes, with no spillover observed in simulations and experiments. The proposed method simplifies the design of PPF controls and opens up new opportunities for a more widespread use of Active Vibration Control (AVC) techniques.