No.1（2006）9.A Distributed Voting Technique for Walking Support Systems for Visually Impaired People

Mamoru Ohara, Hiroshi Okano, Hiroshi Kawamura

Development of information technologies and networks enables us to support independent outdoor walking of visually impaired people by voice navigation using personal digital assistances (PDA) and wireless high-speed networks connected to the Internet. Many researchers are studying technologies for introducing into the walking-support systems features, which protect blind people from traffic hazards using dynamic information read from sensors. However, few reports about the dependability and safety of such technologies have been presented. In this paper, we propose a distributed voting technique for walking-support systems for visually impaired people. The proposed technique uses three identical sensor nodes, which monitor the same area, and votes between the outputs of the sensors in order to mask errors of one of the sensors. Past voting systems were typically constructed with tightly-coupled special devices, and thus, are difficult to use outdoors. In contrast, we construct the proposed system with COTS embedded computers and network devices. We connect the embedded computers with a common wired LAN and present information to the user via wireless networks. We implemented an experimental system and measured overheads for distributed voting. We found that the experimental system had high dependability and sufficient responsiveness for supporting pedestrians.

Keywords

walking-support system for visually impaired people, dependable systems, distributed voting redundancy

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