3-D mapping in real time, without the drift

Computer scientists at MIT and the National University of Ireland (NUI) at Maynooth have developed a mapping algorithm that creates dense, highly detailed 3-D maps of indoor and outdoor environments in real time. The researchers tested their algorithm on videos taken with a low-cost Kinect camera, including one that explores the serpentine halls and stairways of MIT's Stata Center. Applying their mapping technique to these videos, the researchers created rich, three-dimensional maps as the camera explored its surroundings. As the camera circled back to its starting point, the researchers found that after returning to a location recognized as familiar, the algorithm was able to quickly stitch images together to effectively "close the loop," creating a continuous, realistic 3-D map in real time. The technique solves a major problem in the robotic mapping community that's known as either "loop closure" or "drift": As a camera pans across a room or travels down a corridor, it invariably introduces slight errors in the estimated path taken.