Fuzzy-logic-based Walking Context Analysis for Visually Impaired Navigation

Abstract

In this work, we present a walking context analysis for the electronic navigation of visually impaired persons. The walking context is defined as the safety level of the walking condition. An extensive literature review provided the framework for the model developed in this research. A hybrid fuzzy logic model is built to evaluate this safety level on the basis of several environmental and personal factors identified in the navigation. Range measurements related to the obstacles in the surrounding environment are acquired by sonar sensors, and personal information taken by the prototype is the input to the fuzzy logic model, which is used to evaluate the safety level of the current walking context of the visually impaired person. An audio feedback relevant to the walking context is provided, indicating the safety level and direction of motion. The obtained results proved the successful operation and effectiveness of the fuzzy control in reducing the navigation time and increasing safety because it clarifies the uncertainty in each situation as compared with the nonfuzzy approach. The current status of the work and future developments are presented in this paper.

A Systematic Review of Wearable Devices for Orientation and Mobility of Adults With Visual Impairment and Blindness

“…Silva and Wimalaratne [63], [64] developed a belt with ultrasonic sensors to assist indoor navigation. While in [63], Silva and Wimalaratne initially focused only on the obstacle's detection and the fuzzy logic model to assess the safety level of the environment, in [64], they added the object recognition model by fusing sonar and vision sensors.…”

“…Among sensor-based technologies, ultrasonic sensors were the most used in the included studies (n = 24). The use of ultrasonic sensors has demonstrated several benefits for mobility performance, including a decrease in navigation time [13], [36], [63], and detection of complex obstacles such as stairs [13], [36] and moving obstacles [7].…”

“…The user interface was provided as output either by warning the user through voice commands, as observed in Bai et al [28], Ling et al [1], Siddhartha et al [62], Takefuji et al [68], or as a smartphone application featured in Lee and Medioni [49], Silva and Wimalaratne [63], [64], and Vignesh et al [70]. In Lee and Medioni [49], the user could choose where to go from a list of registered places or translate the names of the places by speech recognition.…”

Context-Aware Assistive Indoor Navigation of Visually Impaired Persons

“…A detailed description of the approach to walking context analysis can be found in our previous publication. (22) Audio feedback: Feedback corresponding to the vision sensor is prompted via the audio feedback method. Haptic feedback: The detection of obstacles by sonar sensors is performed via tactile units.…”

Development of Walking Assistive Cane for Obstacle Detection and Location Recognition for Visually Impaired People

“…There have been many other studies on walking assistive devices for visually impaired people, but most of them had problems with the cost and recognizing the user's location. (9)(10)(11) Accordingly, it is necessary to develop a cost-effective device with various functions such as obstacle detection, location recognition, and the provision of safety in dark environments by considering usability regardless of age and country. (12)(13)(14) In this study, we developed a cost-effective walking assistive cane that can recognize the current location for visually impaired people.…”