Voice coil motor sensor and controller

摘要

A voice coil motor displacement sensor and a voice coil motor controller that uses said sensor. The sensor configured to apply an alternating measurement signal at a predetermined frequency to a voice coil motor, the sensor configured to use a measure of a voltage across and a current through the voice coil motor to determine its impedance at the predetermined frequency and determine an estimated displacement of said voice coil motor using said impedance and a predetermined displacement-impedance function.