A Comprehensive Survey of Navigation Systems for the Visual Impaired

Sight is essential for humans to navigate their surrounding environment independently. Tasks that are simple for the sighted are often close to impossible for the visually impaired. Throughout the years, many researchers dedicated their time and efforts to design and implement technologies and devices that can help the visually impaired to navigate in unknown areas independently. A navigation assistive system for the visually impaired is built on multiple components of which localization, navigation, obstacle avoidance, and human-machine interaction form the essential components. Individual components have been explored extensively in the literature and it is a daunting task to review it in its entirety. In this paper, a compact but comprehensive collection of available methods to build each component has been provided. The discussed methods may not have been implemented for a navigation assistive technology for visually impaired directly but they can be employed to build an individual building block. Given that every approach has its own challenges, methods to combat those challenges have been presented. The purpose of this paper is to provide researchers with a shortcut to review most of the available methods to build each component, provide them with the essential knowledge to understand the nuances in each component and give them a baseline to start with.