A Self Navigation Aid for Visually Impaired Persons: An Assistive Technology Based Approach

Abstract

Mobility of the visually impaired people is a growing problem, especially in outdoor spaces. Travelling independently in today’s busy road systems is not easy for them. Even the popular navigation aids such as white canes and guide dogs do not make them totally independent at all times or they might not be available at affordable prices. Even though there are several travel aids developed, a shortfall of a navigation guide with a bearable cost is still remaining. Human navigation is a broad domain, and getting from one place to another in a range of a walking distance is a small portion out of it. This research is focused on guiding an individual to walk to a destination from a starting point in an outdoor environment. A prototype system is developed to address this problem as an assistive technology based approach. This self-navigation aid consists of a smart mobile device, a wearable tactile belt and an earphone. It was designed and implemented to get the type of place as voice input, find a desired place nearby as the destination through Wikitude, the augmented reality browser and guide to reach the destination with the help of voice and tactile feedbacks. Location based technologies and the inertial sensors of smart mobile devices such as the accelerometer and the magnetometer were used to guide to the destination. Experiments were conducted module-wise to measure the accuracy and user friendliness of the prototype. Results indicate that the voice input module is 76% accurate and 77% user friendly, guiding module is 64.28% accurate and 71.35% user friendly and the voice feedback with tactile feedback module is 81.5% understandable. Compared to the existing navigation aids, this system is an effective and highly usable system in a bearable cost because, the smart mobile device includes the sensors itself and the electronic equipments used on tactile belt are in achievable cost. Conclusions are made that augmented reality can also be used in systems for visually impaired. A tactile belt is an effective output mode to give feedbacks in navigation aids when combining with voice outputs. Although the guiding with orientation is not more secured in public roads if improved with a secured mechanism this system can be a useful achievement to the visionless world for travelling independently.