Abstract
This paper proposes a new type of seism-type sensor for measuring both of absolute velocity and displacement signals. In order to constract the active vibration control systems with the state feedback, it is necessary to combine an absolute displacement and velocity sensor with this control system. The absolute sensor is realized by seismic type one. The measuring frequency at lower range is determined by the natural frequency of the sensor. In the paper, a servo control system is applied for reducing the natural frequency actively. It is demonstrated that the measuring range is expanded about ten time at low frequency using the control system.
