Apparatus for measuring displacement and method of use thereof

摘要

A sensor system for measuring displacement includes a primary coil wound around a longitudinal axis and at least one secondary coil wound around the longitudinal axis. Each secondary coil has a winding density distribution that varies between the ends thereof. The winding direction of each secondary coil varies between a clockwise winding direction between the ends thereof. A coupler is positioned adjacent the primary coil between the ends thereof. The coupler includes a resonating circuit configured to resonate at a resonating frequency. The coupler or the coils are configured to move relative to the other of the coupler or the coils. A control system excites the primary coil with a first step of a signal and receives from each secondary coil in response thereto a time varying signal. Each time varying signal includes a ringing component superimposed on a time varying component temporally adjacent the first step of the signal. The control system acquires plural samples of each time varying signal after the ringing component thereof dissipates and determines therefrom a position of the coupler along the longitudinal axis.