1305 Sensors and Materials, Vol. 31, No. 4 (2019) 1305–1324 MYU Tokyo S & M 1858 * Corresponding author: e-mail: chathurika@iat.cmb.ac.lk ** Corresponding author: e-mail: spw@ucsc.cmb.ac.lk https://doi.org/10.18494/SAM.2019.2232 ISSN 0914-4935 © MYU K.K. https://myukk.org/ Fuzzy-logic-based Walking Context Analysis for Visually Impaired Navigation Chathurika Sewwandi Silva 1* and Prasad Wimalaratne 2** 1 Faculty of Technology, University of Colombo, Kaduwela Rd, Sri Jayawardenepura Kotte, Sri Lanka 2 University of Colombo School of Computing, 35 Reid Ave, Colombo 7, Sri Lanka (Received December 12, 2018; accepted March 8, 2019) Keywords: context aware, fuzzy logic, assistive technology, wearable sensors, human–computer interaction 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. 1. Introduction A person’s mobility consists of several tasks such as path planning, navigation, obstacle avoidance, and environmental sensing. A visually impaired person may fail to accomplish the above tasks owing to the probability of high risk and failure associated with their impaired navigation. A guide dog and a white cane are the traditional navigation aids used by visually impaired persons. A guide dog is costly and has a limited lifetime, whereas a white cane can only aid visually impaired persons sense their immediate surroundings. Therefore, visually impaired persons’ navigation can be supported by electronic travel aids (ETAs), which consist of appropriate sensors. This sensory information available from the ETAs can be used to provide knowledge about the context of the current environment. Context-aware pervasive ETAs must be flexibly adaptable to changes in the current context and provide the information considered with the current context for navigators. Context