Events Calendar

PhD Defense - Tung Sing Leung

Date: Thursday April 9th, 9.30am
Location: SAL 213
Title: Outdoor Visual Navigation Aid For The Blind In Dynamic Environments
PhD Candidate: Tung-Sing Leung

Committee:
Prof. Gerard G Medioni (Chair)
Prof. Laurent Itti
Prof. James D. Weiland (outside member)

Abstract:
This thesis proposes a visual navigation aid for the blind. Our goal is to develop a wearable system to help the visually impaired navigate in highly dynamic outdoor environments. The proposed solution uses both visual sensing and existing map available online. Our work focus on two parts : visual odometry (VO) and localization. We propose different methods to compute the visual odometry even in clutter environments using either wearable stereo camera or smartphone. For the case of stereo camera, instead of computing egomotion from 3D point correspondences in consecutive frames, we propose to find the ground plane, then decompose the 6-DoF egomotion into a motion of the ground plane, and a planar motion on the ground plane. The ground plane is estimated at each frame either by analysis of the disparity array or approximated from the Inertial measurement unit (IMU) reading. We have extended our visual odometry to monocular system so that the proposed framework is applicable to smartphone which is more accessible than the stereo camera. To further improve the accuracy of the visual odometry and correct the drift caused by dead reckoning during long navigation, we combine visual odometry with the semantic information available in map to estimate the global coordinates of the walking user. The motion estimation results are fed into a Monte Carlo Localization framework which localizes the user by matching the local motion trajectory with the shape of the street network found in the map. We validated our system on real scenario of hours of walking around in both open terrain and urban environment. Experimental results show that our method not only corrects the cumulative drifting error but also manages to recover from temporary loss.

Location: Henry Salvatori Computer Science Center (SAL) - 213

Audiences: Everyone Is Invited

Contact: Lizsl De Leon