SEPTEMBER 2023 IEEE ROBOTICS & AUTOMATION MAGAZINE 119 0.05 -0.05 0.2 Section 1 Section 2 0.4 0.6 X (m) (a) 0.5 16 s 2 s 4 s (1) 0.4 0.2 2 s 16 s 1 s t = 0 s 4 s (3) 0.4 0.2 8 s Z (m) Z (m) 0.5 1 s t = 0 s 8 s X (m) 1 0.4 0.2 -0.2 -0.4 -0.2 -0.4 X (m) 1 0.4 0.2 -0.2 -0.4 (b) 50 40 30 20 10 -10 3 2 1 -0.2 -0.4 05 10 Time (s) -1 -2 -3 Cable 1 Cable 2 Cable 3 Cable 4 Cable 5 Cable 6 Cable 1 Cable 2 Cable 3 Cable 4 Cable 5 Cable 6 0.4 0.2 05 10 15 Time (s) t = 10 s (1) 05 10 Time (s) 0.4 0.2 05 10 15 Time (s) -0.5 t = 25 s (4) 15 (3) -0.5 0.5 Z (m) (c) FIGURE 11. The control of a soft manipulator. (a) The definition of the manipulator with six actuators. (b) The circular trajectory control. (c) The fixed position and orientation control under gravity. Here, (1) and (2) are the outputs of the closed-loop proportional derivative controller, while (3) and (4) are those of an open-loop input. -1 (2) 15 -0.5 0.5 -0.5 Z (m) X (m) 0.5 1 t = 0 s 0 50 40 30 20 10 (4) -10 05 10 15 Time (s) -10 -0.5 X (m) 0.5 1 t = 0 s 0 -0.5 -1 0.8 10 Y (m) 50 40 30 20 10 1 0.5 05 10 Time (s) (2) Cable 1 Cable 2 Cable 3 Cable 4 Cable 5 Cable 6 02 46 810 Time (s) 20 10 01020 Time (s) Cable 1 Cable 2 Cable 3 Cable 4 Cable 5 Cable 6 20 25 Y (m) Y (m) Actuator Strength in N Cable Tension in N Z (m) Error