Sea-U-Dragon: A Lightweight Unmanned Underwater Vehicle for Robot-Environment Interaction

Although unmanned underwater vehicles (UUVs) exhibit significant advantages in coastal water applications (e.g. underwater grasping), dynamic and disturbed environments, along with the uncertainties in underwater positioning and navigation pose challenges to dynamic interaction with underwater environments. To deal with these challenges, this paper explores the underwater robot-environment-interaction (REI) task by introducing a lightweight UUV named Sea-U-Dragon. Sea-U-Dragon employs an active-passive com-pliant control strategy, featuring a flexible end effector designed to passively adapt to underwater dynamic changes, along with an uncertainty disturbance estimator (UDE)-based dynamic motion/force controller to compensate for underwater uncertainties. Finally, the trajectory following experiments and dynamic force tracking demonstrations justify the maneuverability of Sea-U-Dragon and its ability to perform dynamic interaction tasks.