RoboPhysics inspired experiments to understand how canines move over regular obstacle arrays

Animals move with economy and dexterity that far exceed their robotic counterparts, although robots appear to be catching up. Combined Robophysical and animal experiments have the potential to reveal general principles of legged locomotion. Recent robot experiments have shown that changes in gait can have large effects on locomotor behavior when moving over regular obstacle arrays. For example, changing gait between trot and bound alters the stable heading of travel over the obstacles. Inspired by this, we hypothesized that canines would strongly adapt their gait when confronted with similar obstacles. Surprisingly, they did not exhibit large changes in gait. Therefore, in this study we step back to characterize changes in basic stride parameters and spatial aspects of locomotion. These include stride length, heading relative to the obstacles, and comparisons to movement over flat ground. We report results from 9 dogs moving over domed obstacles with spacing that brackets their natural trotting stride length (80, 100, and 120 percent). These studies may reveal how legged systems can utilize their interaction with complex environments for steering, course planning, and/or more stable and energetically efficient movement.