An Active Vibration Isolation System Using a Loop Shaping Control Technique

A four-mount active vibration isolation system (AVIS) is developed using voice coil actuators. The flexible body modes in the upper plate of the AVIS can cause an instability problem due to control signal whose frequency is close to the resonant frequency of the flexible modes. The loop shaping technique is applied to reduce the amplitude of the control signal. The performances of the active vibration isolation system proposed in the work are investigated by comparing with the passive isolation system using the atomic force microscope (AFM) images.