Constraint-based Whole-Body-Control of Mobile Manipulators in Human-Centered Environments

Abstract

In this work, we describe a ROS-based method for whole-body control (WBC) of mobile manipulators in the context of safe human-robot interaction. Our method is based on cyclic quadratic programming (QP) with a set of simultaneously active tasks that define constraints. The importance of different tasks is captured through priorities and weights. Robot behavior can be changed at run-time by re-configuring the active tasks through ROS interfaces. We evaluate the suitability of our method for safe human-robot collaboration in a Gazebo simulation. We show that our method lets the mobile manipulator perform evasive motions while staying consistent with other tasks if possible. At the same time, self-collisions and static obstacles are avoided. If a given safety threshold is crossed, the robot comes to a safe stop. Operation continues once the distance is high enough again.