5 10 20 -5 0 30 0 10 20 -5 0 30 20 0 -20 -40 -60 -80 0 Yaw (°) 0 0 10 20 Joint2 (°) 50 0 0 10 20 Time (s) 30 Roll (°) 20 Y (m) 10 20 0 10 20 20 0 10 20 Time (s) 0 10 20 10 20 30 30 10 20 30 0 0 10 20 Time (s) 0 20 0 -20 -40 -60 -80 0 50 -50 30 30 -5 0 0 0.5 30 20 30 1.5 10 10 5 0 30 0 -5 0 30 -2 50 -50 0 10 2 0 30 1.5 Z (m) 0 Z (m) -2 Joint1 (°) 30 Joint1 (°) Pitch (°) Y (m) 0 -50 20 5 2 0.5 -2 10 Pitch (°) 0 0 Yaw (°) -2 0 Joint2 (°) 0 5 2 X (m) Roll (°) X (m) 2 30 (a) 50 0 -50 0 10 20 Time (s) 30 (b) Figure 10. The time histories of the aerial manipulators' state variables for the first scenario. The position, attitude, and joint angles of (a) the left aerial manipulator and (b) the right aerial manipulator. The desired trajectories are shown with dashed lines, and the actual trajectories are indicated by solid lines. 5 20 40 -2 0 20 40 0 20 40 60 50 0 0 20 40 Time (s) 60 40 Roll (°) 0 Z (m) 40 20 40 0 20 40 Time (s) (a) 60 60 0 20 40 20 40 60 60 0 -100 -200 -300 -400 0 20 40 60 0 0 20 40 Time (s) 0 -5 0 50 -50 40 60 0 0.5 60 20 5 1.5 20 0 -5 0 60 0 60 50 -50 0 40 -2 20 Joint1 (°) 0 20 2 Yaw (°) 0 -100 -200 -300 -400 0 Joint2 (°) Z (m) Joint1 (°) 0 60 0 -5 0 60 1.5 -50 40 Y (m) Pitch (°) 0 0.5 -2 20 5 2 Y (m) -5 0 60 Pitch (°) 0 0 Yaw (°) -2 0 Joint2 (°) 0 5 2 X (m) Roll (°) X (m) 2 60 50 0 -50 0 20 40 Time (s) 60 (b) Figure 11. The time histories of the aerial manipulators' state variables for the second scenario. The position, attitude, and joint angles of (a) the left aerial manipulator and (b) the right aerial manipulator. The desired trajectories are shown with dashed lines, and the actual trajectories are indicated by solid lines. 84 * IEEE ROBOTICS & AUTOMATION MAGAZINE * december 2018