Bio-Inspired Rough Terrain Contact Patch Perception

We present a new bio-inspired system for automatically finding foot-scale curved surface patches in rough rocky terrain. These patches are intended to provide a reasonable set of choices for higher-level footfall selection algorithms, and are pre-filtered for several attributes-including location, curvature, and normal-that we observed humans to prefer. Input is from a 640 x 480 depth camera augmented with a 9-DoF inertial measurement unit to sense the direction of gravity. The system is capable of finding approximately 700 patches/second on commodity hardware, though the intention is not to find as many patches as possible but to reasonably sample upcoming terrain with quality patches. Sixty recordings of human subjects traversing rocky trails were analyzed to give a baseline for target patch properties. While the presented system is not designed to select a single foothold, it does find a set of patches for possible footholds which are statistically similar to the patches humans select.