@article{ref1,
title="Viability, task switching, and fall avoidance of the simplest dynamic walker",
journal="Scientific reports",
year="2022",
author="Patil, Navendu S. and Dingwell, Jonathan B. and Cusumano, Joseph P.",
volume="12",
number="1",
pages="e8993-e8993",
abstract="Walking humans display great versatility when achieving task goals, like avoiding obstacles or walking alongside others, but the relevance of this to fall avoidance remains unknown. We recently demonstrated a functional connection between the motor regulation needed to achieve task goals (e.g., maintaining walking speed) and a simple walker's ability to reject large disturbances. Here, for the same model, we identify the viability kernel-the largest state-space region where the walker can step forever via at least one sequence of push-off inputs per state. We further find that only a few basins of attraction of the speed-regulated walker's steady-state gaits can fully cover the viability kernel. This highlights a potentially important role of task-level motor regulation in fall avoidance. Therefore, we posit an adaptive hierarchical control/regulation strategy that switches between different task-level regulators to avoid falls. Our task switching controller only requires a target value of the regulated observable-a &quot;task switch&quot;-at every walking step, each chosen from a small, predetermined collection. Because humans have typically already learned to perform such goal-directed tasks during nominal walking conditions, this suggests that the &quot;information cost&quot; of biologically implementing such controllers for the nervous system, including cognitive demands in humans, could be quite low.<p /> <p>Language: en</p>",
language="en",
issn="2045-2322",
doi="10.1038/s41598-022-11966-3",
url="http://dx.doi.org/10.1038/s41598-022-11966-3"
}