Compliant Explicit Reference Governor for Contact Friendly Robotic Manipulators

-- This paper introduces the Compliant Explicit Reference Governor (C-ERG), an extension of the Explicit Reference Governor that allows the robot to operate safely while in contact with the environment. The C-ERG is an intermediate layer that can be placed between a high-level planner and a low-level controller: its role is to enforce operational constraints and to enable the smooth transition between free-motion and contact operations. The C-ERG ensures safety by limiting the total energy available to the robotic arm at the time of contact. In the absence of contact, however, the C-ERG does not penalize the system performance. The emerging trend in the modern industry is to prioritize flexibility [1]. Until recently, robotics has been dominated by sampling-based motion planning which places an emphasis on "collision-free" paths to avoid harming itself or anything in its path [2].