Development and Control of an Underwater Vehicle-Manipulator System Propelled by Flexible Flippers for Grasping Marine Organisms

Robots have the potential to assist and complement humans in the exploration of hostile environments. For example, underwater vehicle-manipulator systems (UVMSs) have been researched and applied in underwater operations. Motivated by the need for collecting marine organisms cultivated in shallow sea aquafarm, a lightweight and portable UVMS propelled by flexible flippers (named, F-UVMS), rather than typical propellers or jet-based propulsion systems, is investigated. To this end, integrative mechatronic design of F-UVMS is first presented, involving six flipper propulsors for generating thrust in a flapping way, a four-degree-of-freedom arm for grasping, and a certain amount of onboard sensors for environment perception. A thrust-power measurement platform is established to evaluate thrust-power relationship for different sizes and stiffness of flippers. Meanwhile, the locomotion modalities of F-UVMS are analyzed. A framework based on the nonlinear model-predictive control method is implemented to govern autonomous tracking marine organisms. The capabilities of F-UVMS are validated through a series of experiments in laboratory pool and field missions in real sea conditions.

Automated summary

Robots have the potential to assist and complement humans in hostile environments. Researchers have designed a lightweight and portable underwater robot, propelled by flexible flippers instead of traditional propellers or jet-based propulsion systems. The robot features six flipper propulsors, a four-degree-of-freedom arm, and onboard sensors for environment perception. The capabilities of the robot have been validated through experiments in laboratory and real sea conditions.