Stairs detection with odometry-aided traversal from a wearable RGB-D camera

Abstract

Stairs are one of the most common structures present in human-made scenarios, but also one of the most dangerous for those with vision problems. In this work we propose a complete method to detect, locate and parametrise stairs with a wearable RGB-D camera. Our algorithm uses the depth data to determine if the horizontal planes in the scene are valid steps of a staircase judging their dimensions and relative positions. As a result we obtain a scaled model of the staircase with the spatial location and orientation with respect to the subject. The visual odometry is also estimated to continuously recover the current position and orientation of the user while moving. This enhances the system giving the ability to come back to previously detected features and providing location awareness of the user during the climb. Simultaneously, the detection of the staircase during the traversal is used to correct the drift of the visual odometry. A comparison of results of the stair detection with other state-of-the-art algorithms was performed using public dataset. Additional experiments have also been carried out, recording our own natural scenes with a chest-mounted RGB-D camera in indoor scenarios. The algorithm is robust enough to work in real-time and even under partial occlusions of the stair.

Expanding the Detection of Traversable Area with RealSense for the Visually Impaired

“…Perez-Yus used the RANSAC algorithm to segment planes in human-made indoor scenarios pending dense 3D point clouds. The approach is able to extract not only the ground but also ascending or descending stairs, and to determine the position and orientation of the user with visual odometry [36]. Lee also incorporated visual odometry and feature-based metri-topological simultaneous localization and mapping (SLAM) [37] to perform traversability analysis [26,38].…”

Indoor Navigation Systems for Visually Impaired Persons: Mapping the Features of Existing Technologies to User Needs

“…An RGB-D camera [45][46][47][48][49][50][51][52] uses a color sensor that takes RGB values and an IR depth sensor that takes image depth data with high accuracy. IR light is used for depth data collection.…”

A Ground Plane Hazards Detection Tool for the Visually Impaired

“…Staircases are one of the most common artificial structures in daily environment to provide multilevel reaching possibilities [3]. However, staircases are also one of the most dangerous obstacles.…”