Motion planning for hand-over between human and robot

In the future, robots may perform cooperative tasks with humans in daily life. In this paper, the authors focus on a hand-over motion as an example of cooperative work between a human and a robot, and propose an algorithm which enables a robot to perform a human-like motion. First the authors analyze trajectories and velocity patterns of a hand-over motion performed by two humans. The experimental results show that a receiver's motion during hand-over has some typical characteristics. The authors then confirm that a human-like motion can be generated using these characteristics. Finally, the authors plan the robot's motion considering these results. Initially, two kinds of potential fields are used to generate a motion command which leads the robot along a trajectory similar to that followed by the human. In addition, more precise motion is considered at the end of the hand-over operation to guarantee accurate positioning and to soften the shock of contact. Simulation results show the validity of the proposed method.