Acoustic beamforming analysis for wearable blind aid applications

Abstract

The World Health Organisation estimates 36 million are blind worldwide; in addition, 217 million have severe or moderate visual impairment. Over the past decades, there has been substantial research in alleviating blindness and visual impairment. However, the blind community has yet to widely accept a single electronic travel aid (ETA) solution; the low cost white cane still remains the most popular device for orientation and mobility. One major limitation of current ETAs is their poor cost-benefit ratio. However, semiconductor advances may have reached a point where previous limitations are now surmountable as miniaturisation, flexible, low-cost and low-power circuits have been key enablers of wearable technology. Sonar has consistently been the preferred modality for single-sensor ETAs. The thesis aims to study performance characteristics of various beamforming aspects in their relation to developing a wearable-sonar system for blind aid applications. The scope of analysis covers 1) Classical Beamfomers 2) Beamforming Augmentation (Geometry, Shading, Adaptive Algorithms) 3) Spherical (3D) Beamsteering and Conformal Arrays