Different underwater robots have been trialed over the years, but many have struggled with performing near-seabed observations because they disturb the local seabed by destroying coral and disrupting the sediment. Researchers from Harbin Engineering University in China, have recently developed a maneuverable underwater vehicle that is better suited to seabed operations because it doesn’t disturb the local environment by floating above the seabed and possessing a specially engineering propeller system to maneuver. These robots could be used to better protect the seabed while studying it, and improve efforts to preserve marine biodiversity and explore for underwater resources such as minerals for EV batteries. Many underwater robots are wheeled or legged, but these robots face substantial challenges in rugged terrains where obstacles and slopes can impede their functionality but can also damage coral reefs.
Existing options disturb the sediment on the seabed because their thrusters create a downward current during ascension. The waves generated as the propeller’s wake directly hit the seafloor in most floating robots, which causes sediment to move in the immediate vicinity. In a similar way the particles moving through the water can obscure the view of the cameras on the robot and reduce the quality of the images it captures. After further investigation, researchers found that the robot’s shape influences the local water resistance, or drag, even at low speeds. This led to developing a robot with a flattened body and angling the thruster relative to the central axis. The researchers created a navigational system where the thrusters generate a combined force that slants downwards but still allows the robot to ascend, changing the wake distribution during ascent so that it doesn’t disturb the sediment on the seafloor.
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