Combining human guidance and structured task execution during physical human–robot collaboration

In this work, we consider a scenario in which a human operator physically interacts with a collaborative robot (CoBot) to perform shared and structured tasks. We assume that collaborative operations are formulated as hierarchical task networks to be interactively executed exploiting the human physical guidance. In this scenario, the human interventions are continuously interpreted by the robotic system in order to infer whether the human guidance is aligned or not with respect to the planned activities. The interpreted human interventions are also exploited by the robotic system to on-line adapt its cooperative behavior during the execution of the shared plan. Depending on the estimated operator intentions, the robotic system can adjust tasks or motions, while regulating the robot compliance with respect to the co-worker physical guidance. We describe the overall framework illustrating the architecture and its components. The proposed approach is demonstrated in a testing scenario consisting of a human operator that interacts with the Kuka LBR iiwa manipulator in order to perform a collaborative task. The collected results show the effectiveness of the proposed approach.