Bidirectional Human-Robot Bimanual Handover of Big Planar Object With Vertical Posture

Object handover is one of the basic abilities for the robot to interact with the human. Most of the previous works only focus on the limited handover scenarios where the robot uses one hand to give small objects to the human. In this article, we design a bidirectional bimanual handover system that enables the robot to both give and receive the big planar object with vertical grasp posture. In addition to the basic object handover function, the designed handover system also integrates a position adjustment mechanism to improve the human experience. According to different task states, the system is divided into four modes. In each mode, the robot performs a subtask and switches to the next mode at an appropriate time. We propose a two-finger grip force controller and a dual-arm admittance NN controller to control the robot to generate actual motions. By applying specific locating, trajectory planning, and signal identifying methods, we implement the designed handover system on a Baxter robot. The system is tested on two wooden plates with different widths, thicknesses, and weights. The results show that the robot can perform the handover task safely and effectively with the designed handover system.