Entanglements like vines and branches in natural settings or cords and pipes
in human spaces prevent mobile robots from accessing many environments. Legged
robots should be effective in these settings, and more so than wheeled or
tracked platforms, but naive controllers quickly become entangled and stuck. In
this paper we present a method for proprioception aimed specifically at the
task of sensing entanglements of a robot's legs as well as a reaction strategy
to disentangle legs during their swing phase as they advance to their next
foothold. We demonstrate our proprioception and reaction strategy enables
traversal of entanglements of many stiffnesses and geometries succeeding in 14
out of 16 trials in laboratory tests, as well as a natural outdoor environment.Comment: Submitted to 2023 IEEE/RSJ International Conference on Intelligent
Robots and System