Self-tuning velocity feedback control for a time varying structure using a voltage driven electrodynamic inertial mass actuator

This paper presents research work on self-tuning velocity feedback control units with voltage driven electrodynamic inertial mass actuators (IMAs). Due to the IMAs dynamics such feedback loops are only conditionally stable. Feedback compensators can improve the feedback loop stability. In the literature often ideal current driven IMAs are assumed, while most practical power amplifiers are actually voltage sources. In this paper a feedback compensator for voltage driven IMAs is derived and experimentally validated. The primary structure considered is a base excited single degree of freedom system with variable stiffness. For each stiffness setting there is a specific feedback gain setting that provides optimal control performance. Therefore a self-tuning algorithm is developed that tunes the feedback gain to minimize the kinetic energy of the primary structure, while also considering the stroke and current limits of the IMA. The self-tuning algorithm is experimentally validated for different natural frequency settings.