Estimation of robot execution time for close proximity human-robot collaboration

Task time is essential information for the optimal planning and scheduling of industrial scenarios, such as assembly cells. In Human-Robot Collaboration (HRC), the robot execution time, i.e., the robot task time, depends on the task the human is executing simultaneously to the robot and on the human movements. Indeed, the robot may be requested to modify its speed along a predefined path (i.e., to slow down or to stop its motion) in order to avoid possible collisions with the human. This paper presents an approach for the estimation of the robot execution time, when the robot path and the human task are assigned. Specifically, a workspace segmentation is performed considering the volume occupied by the human and the robot during their motion. Then, this segmentation is exploited for the definition of a set of Markov chains modeling human-robot interaction and allowing the estimation of the robot execution time. Simulated and real test beds are presented and discussed.