RGB-D camera Based Navigation for the Visually Impaired

We present a wearable RGB-D camera based navigation system for the visually impaired. The navigation system is expected to enable the visually impaired to extend the range of their activities compared to that provided by conventional aid devices, such as white cane. Since this design is a successor version of a previous stereo camera based system to overcome a limitation of stereo vision based systems, algorithmic structure of the system is maintained. In order to extract orientational information of the blind users, we incorporate visual odometry and feature based metric-topological (Simultaneous Localization And Mapping) SLAM into our system. We build a vicinity map based on dense 3D data obtained from RGB-D camera, and perform path planning to provide the visually impaired with 3D traversability on the map. The 3D traversability analysis helps subjects steer away from obstacles in the path. A vest-type interface consisting of four microvibration motors delivers queues for real-time navigation with obstacle avoidance. Our system operates at 12− 15Hz, and helps the visually impaired improve the mobility performance in a cluttered environment. The results show that navigation performance in indoor environments with the proposed lightweight and affordable RGB-D camera improves compared to a stereo-vision based system.