Collision Detection with Monocular Vision for Assisting in Mobility of Visually Impaired People

This paper proposes a method for detecting possible collisions using a monocular camera. Robust collision detection from a monocular video stream is a challenging problem with applications ranging from robotics, human navigation and automation. Our target application is an assistive system for aiding visually impaired people to avoid collision to obstacles while walking. The proposed method is based on a new algorithm to estimate the time to collision (TTC) (from an obstacle to the camera plane) using: i) optical flow to estimate motion, ii) the pinhole camera model to get a TTC analytical equation for each pixel and iii) image processing techniques to reduce possible errors. We evaluate the method in three different experiments reflecting different scenarios, allowing a analysis of its performance.