Design, Analysis and Experiments of a High-Speed Water Hovering Amphibious Robot: AmphiSTAR

The development, modeling, and performance of AmphiSTAR, a novel high-speed amphibious robot, are detailed in this paper. The robot is palm-sized and fitted with propellers at its bottom, enabling it to crawl on the ground and hover on the water at high speeds. The design of the AmphiSTAR is inspired by two members of the animal kingdom - the cockroach's sprawling mechanism and the Basilisk lizard's ability to hover on the water at high speeds. We developed a relatively simple physical model of the lift force as a function of the size of the propeller, its submersion level, and rotational speed. We built an experimental setup to validate the results, and the experimental results are consistent with the analytical model. The robot can crawl at 3.6 m/s (13.6 bodylengths/s) and hover continuously on water surfaces at 1.5 m/s (5.6 bodylengths/s) speeds, making it the fastest amphibious robot. Its elevation on the water surface reduces friction, and its high-speed motors provide forward thrust, enabling it to move at high speeds. Additionally, it can swim by rotating its propellers while floating at low speeds and transition from swimming to crawling (see video).