A Dynamic Planner for Safe and Predictable Human-Robot Collaboration

The new face of modern industrial scenarios involves shared workspaces where humans and robots work closely together. To ensure safe human-robot collaboration (HRC), regulations have been updated introducing the ISO/TS15066. However, complying with these regulations often leads to inefficient behavior, such as unnecessarily reducing robot speed or unpredictably changing the robot path, which may negatively affect the operator perception of the robot. In this letter an optimal approach to address together these two issues is proposed. Starting from a desired final configuration, the framework plans a collision-free trajectory for the robot. Subsequently, predictability is taken into account and a set of virtual tubes into which the path of the robot can move is built. Lastly, an optimization problem is solved online to ensure that the robot stays within these tubes and the velocities are compliant with the ISO/TS 15066. The proposed approach has been experimentally validated in two different scenarios: one composed by a mobile manipulator, i.e. a UR10e mounted on a Neobotix MPO-500, and one composed by only a collaborative manipulator, i.e. a UR5e.