• Abstract
• Full-Text PDF [4214 KB]
• Full-Text XML
• Article Versions Notes

• Article Statistics
• PubMed/Medline
• Google Scholar
• Order Reprints

• Cite this article
• Export to BibTeX
• Export to EndNote

• [+] on DOAJ
• Rodríguez, A
• Yebes, J
• Alcantarilla, PF.
• Bergasa, LM.
• Almazán, J
• Cela, A
• [+] on Google Scholar
• Rodríguez, A
• Yebes, J
• Alcantarilla, PF.
• Bergasa, LM.
• Almazán, J
• Cela, A
• [+] on PubMed
• Rodríguez, A
• Yebes, J
• Alcantarilla, PF.
• Bergasa, LM.
• Almazán, J
• Cela, A

•  CiteULike
•  Facebook
•  Mendeley
•  Twitter

This article is

• freely available
• re-usable

Sensors 2012, 12(12), 17476-17496; doi:10.3390/s121217476

Article

Assisting the Visually Impaired: Obstacle Detection and Warning System by Acoustic Feedback

Alberto Rodríguez ¹ , J. Javier Yebes ^1,* , Pablo F. Alcantarilla ² , Luis M. Bergasa ¹ , Javier Almazán ¹  and Andrés Cela ³

¹ Department of Electronics, University of Alcalá, Alcalá de Henares, 28871 Madrid, Spain ² ISIT UMR 6284 CNRS, Université d'Auvergne, 63001 Clermont-Ferrand, France ³ 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

(This article belongs to the Special Issue New Trends towards Automatic Vehicle Control and Perception Systems)

Download PDF Full-Text [4214 KB, uploaded 17 December 2012 10:47 CET]

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

Article Statistics

Cite This Article