A selective negative derivative feedback algorithm to improve stability for inertial actuators

Inertial actuators are widely used in active vibration control, since they don't need to react off the base structure. Then, unlike reactive actuators, they can be used as modules that can be directly installed on a vibrating structure. In many cases, inertial actuators are used to develop some stand-alone active dampers. Such devices are embedded with sensors and a microcontroller, in order to independently perform the vibration control task. This kind of control unit is commonly adopted to implement decentralized architectures. In this work, the main goal was to limit instability phenomena related to the dynamics of inertial actuators. The proposed solution also aims to improve the performance of a decentralized control strategy through a partial sharing of data between devices, without the use of cables. First, the formulation of the modified Negative Derivative Feedback resonant controller is derived; then, the steps of the control strategy are explained, which are based on a preliminary modal identification of the structure and the assignment of a compensator for each resonance frequency to be controlled. Finally, the proposed method is validated with experimental results from a clamped-clamped beam.