Collision-tolerant end-effector position control for mobile manipulator

Robots are expected to be human-friendly and safe in human-robot collaboration environments. This paper presents a new mechanism mounted on a mobile platform with a trunk suspension system which can be safely used in collisions, together with a joint-based control scheme developed to control the position of the end-effector. Under unexpected collision with humans, at first, the trunk with the passive-viscous and elastic elements can deal with contact forces and the mobility of the platform is employed if the trunk is intolerant of the contact forces. Then, the new joint configuration of the manipulator is updated to keep performing a given task. Effectiveness of the proposed mechanism and control method is verified through experiments.