The virtual white cane is a range sensing device based on active triangulation, that can measure distances at a rate of 15 measurements/second. A blind person can use this device for sensing the environment, pointing it as if it was a flashlight. Beside measuring distances, this device can detect surface discontinuities, such as the foot of a wall, a step, or a drop-off. This is obtained by analyzing the range data collected as the user swings the device around, tracking planar patches and finding discontinuities. In this paper we briefly describe the range sensing device, and present an online surface tracking algorithm, based on a Jump-Markov model. We show experimental results proving the robustness of the tracking system in real-world conditions.
D. Yuan, Roberto Manduchi