Fig. 6: Examples of underwater grasping of different objects.

a, The arm accomplishes a search task using the rotary joint at the base to explore the environment horizontally. When contact with the external object (a glass bottle) is detected, the search task stops, the PNS computes the object pose and the grasp is triggered. b, The arm, in a vertical orientation, contacts a cylindrical object and properly triggers ventral bending. c, The distal suction cup is contacted with an empty cup, and only local suction is triggered with dorsal bending. d, The arm, positioned horizontally with its ventral side facing downwards, explores the environment through ventral bending. When detecting a contact (an artificial seastar is used in the example), local suction is activated, and the PNS opportunely computes dorsal bending to retrieve the object.