Dynamics and Control of High Precision Magnetically Levitated Vibration Isolation Systems

In this paper, key issues associated with the dynamics and control of vibration isolation systems are addressed. We first focus on the selection of proper actuator and sensor locations leading to a controllable and observable system. The modal analysis method is used to develop a lumped-parameter model and to investigate the system´s controllability and observability including the coupling effects introduced by the magnetic bearing. This analysis results in necessary and sufficient conditions for proper selection of actuator and sensor locations. Furthermore, the instability effects caused by magnetic bearing dynamics are investigated. A favorable pole-zero plot of the open loop transfer functions is presented along with necessary and sufficient condition for reducing the controller complexity.