Improving Mobility of Pedestrian Visually-Impaired Users

Objective In the present paper the study, design and prototyping of a mobility aid system for visually impaired persons in outdoor scenarios is presented. The application scenario is autonomous mobility in urban context, and, in particular, the living of outdoor public places of tourist/cultural interest and urban routes. Main Content The basic idea behind the project is to realize a safe path that can be followed by the user thanks to a tactile vibration provided by a modified white cane (Smart Cane), potentially usable also as a traditional one; a smartphone provides the user with additional information about the route. The basic guidance function on a safe path is suitable also in an indoor scenario, e.g. in exhibitions, museums, public buildings. Final users were involved in the definition of mobility requirements and during system tests. The safe path is composed by tracks, branch points and points of interest, and is implemented by means of an electrical circuit generating a magnetic field detected by a receiver on the white cane tip. The Smart Cane is equipped with an electronic device (Smart Cane Controller) managing cane functions. The path electrical circuit may be buried in several kinds of ground or placed on ground surface. The user follows the path sweeping the white cane in front of him/her and perceiving a tactile vibration when the Smart Cane tip is in the range of a few tens centimeters from the track centre. The smartphone brought by the user is wirelessly connected to the Smart Cane Controller and to a small portable GPS receiver. The user queries the mobile phone by means of a switchbased user interface on the cane; thanks to GPS positioning information (strict positioning accuracy not needed), the mobile phone provides vocal information about possible destinations, directions and about points of interest. Results The system electronics and the firmware and software applications were completely developed and tested both in lab and in real operating conditions. For the test and Demonstration phase, a bastion on the Walls of Lucca city, Italy, was selected, and the system was tested also with final users. A second run of trials with other users is foreseen in late Spring and Summer 2011. Conclusion The proposed mobility aid system was completely designed, developed and partially tested. A Demonstration phase will allow final users to further test and validate the system, providing hints and feedbacks for a possible engineered future version.