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Assisting the Visually Impaired: Obstacle Detection and Warning System by Acoustic Feedback
Department of Electronics, University of Alcalá, Alcalá de Henares, 28871 Madrid, Spain
ISIT UMR 6284 CNRS, Université d'Auvergne, 63001 Clermont-Ferrand, France
Department of Automation and Industrial Control, National Polytechnic, EC170135 Quito, Ecuador
* Author to whom correspondence should be addressed.
Received: 12 October 2012; in revised form: 23 November 2012 / Accepted: 10 December 2012 / Published: 17 December 2012
Abstract: The aim of this article is focused on the design of an obstacle detection system for assisting visually impaired people. A dense disparity map is computed from the images of a stereo camera carried by the user. By using the dense disparity map, potential obstacles can be detected in 3D in indoor and outdoor scenarios. A ground plane estimation algorithm based on RANSAC plus filtering techniques allows the robust detection of the ground in every frame. A polar grid representation is proposed to account for the potential obstacles in the scene. The design is completed with acoustic feedback to assist visually impaired users while approaching obstacles. Beep sounds with different frequencies and repetitions inform the user about the presence of obstacles. Audio bone conducting technology is employed to play these sounds without interrupting the visually impaired user from hearing other important sounds from its local environment. A user study participated by four visually impaired volunteers supports the proposed system.
Keywords: visually impaired; obstacle detection; stereo camera; ground plane estimation; audio warning
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Rodríguez, A.; Yebes, J.J.; Alcantarilla, P.F.; Bergasa, L.M.; Almazán, J.; Cela, A. Assisting the Visually Impaired: Obstacle Detection and Warning System by Acoustic Feedback. Sensors 2012, 12, 17476-17496.
Rodríguez A, Yebes JJ, Alcantarilla PF, Bergasa LM, Almazán J, Cela A. Assisting the Visually Impaired: Obstacle Detection and Warning System by Acoustic Feedback. Sensors. 2012; 12(12):17476-17496.
Rodríguez, Alberto; Yebes, J. Javier; Alcantarilla, Pablo F.; Bergasa, Luis M.; Almazán, Javier; Cela, Andrés. 2012. "Assisting the Visually Impaired: Obstacle Detection and Warning System by Acoustic Feedback." Sensors 12, no. 12: 17476-17496.