In this paper, an inspection manipulator with a micro-camera at the end was designed for in-situ microscopic observation of samples on the material exposure platform. In order to achieve the positioning requirements, a novel position measurement method for the manipulator was proposed based on monocular microscope vision. First, a planar target was designed for feature detection. Next, the measurement task was performed in two steps respectively. On the image plane, a motion-based active calibration method was used to measure the translation. For the rotation around Z axis, the relationship between the image blur b and the rotation theta was fitted to estimate the rotation from images. In final, the proposed approach was tested in term of accuracy and robustness in ground experimental conditions. The focusing error of the piezoelectric motor was about 1 mu m and the obtained average alignment accuracies were less than 10 mu m in X,Y, and 0.002 degrees around Z, respectively, which satisfied the positioning requirements of the in-situ observation.
