A review of assistive spatial orientation and navigation technologies for the visually impaired

Abstract

Purpose-The overall objective of this work is to review the assistive technologies that have been proposed by researchers in recent years to address the limitations in user mobility posed by visual impairment. Method-This work presents an "umbrella review". Results-Visually impaired people often want more than just information about their location and often need to relate their current location to the features existing in the surrounding environment. Extensive research has been dedicated into building assistive systems. Assistive systems for human navigation, in general, aim to allow their users to safely and efficiently navigate in unfamiliar environments by dynamically planning the path based on the user's location, respecting the constraints posed by their special needs. Conclusions-Modern mobile assistive technologies are becoming more discrete and include a wide range of mobile computerized devices, including ubiquitous technologies like mobile phones. Technology can be used to determine the user's location, his relation to the surroundings (context), generate navigation instructions and deliver all this information to the blind user.

An ARCore Based User Centric Assistive Navigation System for Visually Impaired People

“…Most indoor positioning and tracking technologies were borrowed from autonomous robotics and computer vision. Methods using direct sensing and dead reckoning [7] are no longer qualified options. Yang [8] proposed a Bluetooth RSSI-based sensing framework to localize users in large public venues.…”

“…However, due to the restriction of turn-by-turn path planning, the haptic interaction is unlikely to be used in a continuous path-following interface in assistive systems. Fernandes [7] used perceptual 3D audio as a solution; however, the learning was not easy and the accuracy in real complex scenes needs to be improved. Ahmetovic [15] conducted a data-driven analysis, which pointed out that turn-by-turn audio instructions have considerable drawbacks due to latency in interaction and limited information per instruction.…”

Object Identification and Safe Route Recommendation Based on Human Flow for the Visually Impaired

“…Most of the positioning methods improve their accuracy by measuring the position roughly by radio, such as with the global positioning system (GPS) [7], Bluetooth Low Energy (BLE) [8], Ultra Wide Band (UWB) [9], or RFID [3][4][5], and then correcting the position by dead reckoning or SLAM. SLAM is often used for obstacle detection.…”

“…However, when BLE is used in high-traffic passages, the signal is absorbed and reflected by people, so BLE significantly decreases in accuracy. RFID measures the position with an error of about 10 cm [3][4][5]. The user charges for installing RFID tags on the floor.…”

“…In addition to these auxiliary devices, a navigation system that combines positioning and obstacle detection has been actively researched and developed [2]. The radiofrequency identifier (RFID) can be positioned with an error of about 10 mm [3][4][5]. The user charges for installing RFID tags on the floor.…”