Handing over Objects to Human in a Friendly and Comfortable Manner

In this paper, a robotic motion planning scheme is proposed to generate hand-over motions in a friendly and comfortable manner. Two sub-problems are studied: The determination of the final target position (where the robot should hand over the object to) and the generation of human-like motion in the hand-over process (how the robot should hand over the object to the position). First, experiments of different subjects are conducted to explore the common characteristics in the optimal hand-over positions. The result shows that their joint angles are similar at the optimal hand-over position. Therefore, the optimal hand-over position can be determined by forward kinematics based on the measured average joint angles. Then, two methods are proposed to plan the human-like hand-over motions in an obstacle-free environment and in an obstacle-present environment, respectively. A series of experimental comparisons is conducted to prove the validity of the methods. A robotic arm is controlled to hand over a cube to humans in human-like way and nonhuman-like way. The subjects are asked to grade the hand-over motion of the robotic arm on a scale of 1 to 5. The results show that the hand-over motions planned by the methods proposed in this paper can make people feel safer and more comfortable.