ESTIMATION METHOD OF DISTANCE BETWEEN TRACKING TYPE LASER INTERFEROMETER AND TARGET, AND TRACKING TYPE LASER INTERFEROMETER

摘要

PROBLEM TO BE SOLVED: To estimate an accurate absolute distance during measurement, even when a sensor for detecting deviation of an optical axis is small, and its detection range is small.;SOLUTION: In this tracking type laser interferometer having: a laser interferometer 101; an optical axis deviation detection sensor 102 for detecting the deviation of an optical axis of the laser interferometer; a two-axis turning mechanism 104 for turning the laser interferometer to any optional direction; an angle sensor 105 for detecting a turning angle of the two-axis turning mechanism; a retroreflector 107 for reflecting reflected light to a direction parallel to incident light; and a controller 108 for driving the two-axis turning mechanism so as to track the retroreflector based on signals of the optical axis deviation detection sensor and the angle sensor, stop of the retroreflector is detected, and, during stop of detection, a distance is calculated based on the total sum of the deviation of the optical axis during movement, which is obtained by the optical axis deviation detection sensor, and a turning angle during movement, which is obtained by the angle sensor.;COPYRIGHT: (C)2010,JPO&INPIT