21. Investigation on the Performance of a Velocity Feedback Control Unit for Structural Vibration Control: Theory and Experiments

A valuable solution for structural vibration control of lightly damped systems, subjected to random disturbance, is to provide active damping by generating a control force proportional to the local velocity of the structure. It has been shown in the literature that an optimal feedback gain exists, at which the kinetic energy of the structure is minimised. Furthermore, other studies have shown that the minimisation of the kinetic energy can be approximated with the maximisation of the power absorbed by the control unit, reducing the amount of information required for the estimation of the performance of the control system. In this paper the reduction of flexural vibration on a plate by means of a local velocity feedback control, with a collocated inertial actuator and sensor pair, is considered. The performance of the control unit is investigated both numerically and experimentally, in terms of the kinetic energy of the structure and the power absorbed by the control unit. The influence of the frequency range considered in the assessment of the performance is analysed. In particular, the equivalence between the minimisation of the kinetic energy and the maximisation of the power absorbed is investigated, as a crucial step into the design of a self-contained locally tunable control unit.