A new fast inchworm type actuator with the robust I/Q heterodyne interferometer feedback

The precision stage is an essential device for micromachine assembly systems, and semiconductor equipments. A new fast piezoelectric inchworm type actuator is proposed to implement an actuator-integrated long stroke linear servo stage. An in-and-quadrature phase (I/Q) heterodyne interferometer is devised as a feedback sensor in the servo system, and a synchronized counting method is proposed to measure the position of the stage accurately. Proposed measurement system can measure the precise position of fast moving object with robustness to the vibration of inchworm actuator.