Using relative displacement and relative velocity to obtain absolute displacement with phase compensation

摘要

An absolute displacement sensor (1) is disclosed. The sensor includes a sensor housing (2) as a detection object; a mass body (3) which has a mass m and is movably supported by the sensor housing (2) with a spring coefficient k and an attenuation coefficient c; detection means (4) which electrically detects a relative velocity of the sensor housing (2) for the mass body (3); feedback control means (5). The feedback control means (5) feeds back a relative displacement using positive feedback and a relative acceleration obtained by primary differentiation of the relative velocity using negative feedback so as to control an absolute displacement of the mass body (3) caused by the absolute displacement of the sensor housing (2). Phase delay compensation means (6) performs phase delay compensation on the relative displacement.