Receptance based approach for control of floor vibrations

Abstract

Advances in design, materials and construction technologies, coupled with client and architectural requirements, are some of the drivers for light-weight and slender pedestrian structures, which are becoming increasingly susceptible to human induced vibrations. The use of active control techniques is progressively being viewed as a more feasible approach for suppressing such vibrations compared with traditional passive technologies. In this paper, the principles of the receptance based approach are exploited to design appropriate feedback gains that place the eigenvalues of selected vibration modes of an experimental footbridge structure at selected locations thereby enhancing its vibration performance. These studies are based on a single-input multiple-output (SIMO) controller structure comprising of a single control actuator and two sensors. It is seen that this has the potential to offer additional design freedoms beyond purely a direct velocity feedback (DVF) controller. A comparative study is carried out with a DVF controller implemented in a single-input single-output (SISO) scheme. This work presents the analytical determination of appropriate feedback gains from results of experimental modal analysis (EMA) on the structure and thereafter the experimental implementation of these feedback gains. Vibration mitigation performance is evaluated through both changes in measured transfer functions and reductions in response under single pedestrian excitation.