Abstract
This paper proposes a new type of absolute displacement and velocity sensor based on the principle of servomechanism. Because measuring range is over natural frequency, it is difficult to measure a low frequency vibration using conventional seismic type sensor. In order to expand measuring frequency range, sensor with the low natural frequency is realized by using feedback control techniques. It is shown that the sensor with small size and lightweight have a low frequency measuring range. This sensor is used for controlling vibration using active dynamic vibration absorber.
