Computer Science Colloquium

Date: August 18, 2006
Time: 3:00p.m
Place: Room 800,
Center for Visualization and Virtual Environments,
1 Quality St. Lexington KY 40507
Visual Localization within a World composed of Planes

Friedrich Fraundorfer
University of Kentucky
ABSTRACT
Visual map building and localization for mobile robots is a wide spread field of research. Research done so far has already produced a vast variety of different approaches, yet key questions are still open. In this work we present novel approaches focussing on visual map building and global localization. First we propose a piece-wise planar world representation which uses small planar patches as landmarks. The new world representation is designed to ease the landmark correspondence problem. The map is augmented with the original appearances of the landmarks and invariant descriptors combining geometry and appearance based features in a local approach. For the building of the piece-wise planar map we make use of the recent advances in wide-baseline stereo matching by using local detectors. The current state-of-the-art of local detectors is revised in this work and a new method to evaluate the performance of the different methods is proposed. Based on the evaluation results new methods for wide-baseline region matching and piece-wise planar scene reconstruction are presented. A map building algorithm is presented, which creates a piece-wise planar world map where the world map consists of a set of linked metric sub-maps. Second a novel algorithm for global localization from a single small landmark match is presented. The method produces an accurate 6DOF pose estimate, gaining benefits from the piece-wise planar world representation. Accurate pose estimation from a single small landmark makes the localization very robust even against large occlusions. Map building and localization are experimentally evaluated on two indoor scenarios. Map building and localization prove to be competitive to other state-of-the-art approaches. In fact, the localization accuracy is competitive to recent approaches, but gets computed from a single landmark match only. The experimental results successfully demonstrate the benefits and strengths of our novel approach.




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