Abstract: Based on photogrammetry technology, a novel localization method of micro-polishing robot, which is restricted within certain working space, is presented in this paper. On the basis of pinhole camera model, a new mathematical model of vision localization of automated polishing robot is established. The vision localization is based on the distance-constraints of feature points. The method to solve the mathematical model is discussed. According to the characteristics of gray image, an adaptive method of automatic threshold selection based on connected components is presented. The center coordinate of the feature image point is resolved by bilinear interpolation gray square weighted algorithm. Finally, the mathematical model of testing system is verified by global localization test. The experimental results show that the vision localization system in working space has high precision.

Key words: vision localization, micro-polishing robot, threshold segmentation, distance constraint