4 iXi . 2 012345 1 -1 -2 -3 1 xo yo 0.5 zo xro yro zro 012345 t (s) (a) 1 0.8 0.6 0.4 0.2 0.5 Xo Xoinitial Xorelease Xolanding XEEleft XEEright xo . yo . zo . xDo . yDo . zDo . 012345 iXcmdi . Y (m) 0.8 0.6 -0.5 0.4 0.2 (b) Figure 7. (a) The motion of the object during the fast grabbing and tossing task. Top: the norm of the linear velocity. Middle: the linear velocity. Bottom: position. The grabbing and lifting phases start at the contact indicated by a cyan vertical line, whereas the release instant is indicated by the magenta vertical line. (b) The 3D trajectories of the overall dual-arm-and-object system during the fast grabbing and tossing task. The red continuous and dotted lines are for the left and right end effector, respectively, while the blue line is for the object. The object at its initial and final location is depicted by the light green and blue box, respectively. The magenta arrows indicate the direction of the impact velocity when the contact is established. 134 * IEEE ROBOTICS & AUTOMATION MAGAZINE * SEPTEMBER 2022 X (m) 1 X (m) vo (m/s) vo (m/s) Z (m) Contact Toss Contact Toss Contact Toss