Aerial obstacle detection with 3D mobile devices

In this paper, we present a novel approach for aerial obstacle detection (e.g. branches or awnings) using a 3D smartphone in the context of the visually impaired (VI) people assistance. This kind of obstacles are especially challenging because they cannot be detected by the walking stick or the guide dog. The algorithm captures the 3D data of the scene through stereo vision. To our knowledge, this is the first work that presents a technology able to obtain real 3D measures with smartphones in real time. The orientation sensors of the device (magnetometer and accelerometer) are used to approximate the walking direction of the user, in order to look for the obstacles only in such direction. The obtained 3D data are compressed and then linearized for detecting the potential obstacles. Potential obstacles are tracked in order to accumulate enough evidence to alert the user only when a real obstacle is found. In the experimental section, we show the results of the algorithm in several situations using real data and helped by VI users.J.M. Sáez and M.A. Lozano are supported by the University of Alicante research grant GRE10-21. F. Escolano is supported by the project TIN2012-32839 of the Spanish Government