Human Sensing Using Visible Light Communication
Dartmouth College computer science researchers present LiSense, a first-of-its-kind system that enables data communication and real-time human skeleton reconstruction using Visible Light Communication (VLC). LiSense uses shadows created by the human body from blocked light and reconstructs 3D human skeleton postures in real time. The researchers overcame two key challenges to realize shadow-based human sensing. First, multiple lights on the ceiling lead to diminished and complex shadow patterns on the floor. The team designed light beacons enabled by VLC to separate light rays from different light sources and recover the shadow pattern cast by each individual light. Second, they designed an efficient inference algorithm to reconstruct user postures using 2D shadow information with a limited resolution collected by photodiodes embedded in the floor. They built a 3 m x 3 m LiSense testbed using off-the-shelf LEDs and photodiodes. Experiments show that LiSense reconstructs the 3D user skeleton at 60 Hz in real time with 10° mean angular error for five body joints.
Transcript
00:00:01 [Music] here's a bright idea what if we could use a light around us for more than just illumination research at dnets lab is decoding the information generated by visible light using visible light communication to turn everyday lighting into sensors that can recognize and respond to what we do light rays from multiple sources are
00:00:21 simultaneously picked up by photo diodes in the floor by flashing each light at a different high frequency we can recover the unique shadow cast by each light source we can then use these shadow maps to reconstruct a user skeleton in three-dimensional space tracking Motion in real time and allowing users to interact with their environment using
00:00:40 just the light around them we're making light smart just by waving a hand we can freely control the objects around us play games and track Behavior without cameras or on body devices one day light may even be able to respond to our moods and feelings the possibilities are Unlimited