Improvement of Vibration Isolation Characteristics using Acceleration Feedback Based on Kalman Filter Estimation

A horizontal vibration isolation system utilizing displacement cancellation technique is studied both analytically and experimentally. The isolation and middle tables of the investigated vibration isolation system, involving displacement cancellation technique, are controlled by an infinite stiffness control and positive stiffness control, respectively. In this study, the dynamic characteristics of the vibration isolation system are improved by adding acceleration feedback to the original controllers. MEMS (Micro Electrical Mechanical System) accelerometers are used to measure acceleration for the feedback. Since the acceleration measured by a MEMS accelerometer usually contains undesired noise, the estimated acceleration by Kalman Filter (KF) is used instead of the measured value in the acceleration feedback. The dynamic responses of the system are investigated with the acceleration feedback based on the KF estimation and the measured signal individually. The experimental results show that the KF-estimated acceleration feedback improves the vibration isolation characteristics significantly.