Contact-Driven Posture Behavior for Safe and Interactive Robot Operation

Abstract

When performing tasks in uncertain environments and around humans, robots are likely to collide unexpectedly with people or objects. In order to ensure safety, most approaches rely on collision avoidance and try to prevent any contact from happening, which may result in unnecessary interruption of a task that would be feasible in spite of the obstacle. On the one hand, when an unexpected contact occurs, a safe robot behavior is required. On the other hand, it might be interesting to exploit the contact instead of moving away from it. In this paper, we present a contact-driven approach for safe and interactive robot operation to react to unforeseen contact events. This approach offers the possibility to control the contact while minimizing its effects on the robot tasks. It relies exclusively on the robot model and proprioceptive sensors. It is tested in simulation and hardware experiments on a 7 degrees of freedom robot arm and shows a safe contact behavior that does not interfere with the task, and as little as possible with the robot posture requirements.