Mothership - A Serpentine Tread/Limb Hybrid Marsupial Robot For Usar

In this paper we present a novel serpentine marsupial robot that consists of three articulated modules of 10 treads each, ringing the circumference. The treads of each cylindrical tread module move in two dimensions, resulting in holonomic behavior. The differentially-driven planetary gears permit both transverse and longitudinal tread motion while both motors remain stationary in the module frame of reference. Active articulated joints between the modules enable the navigation of obstacles and climbing steep gradients and steps larger than the diameter of the modules. As a marsupial robot team, the larger MOTHERSHIP carries small, rubble-penetrating CRAWLER robots to assist a search, either via teleoperation or, eventually, via autonomous teaming.