A Miniature Water Jumping Robot Based on Accurate Interaction Force Analysis

Water jumping motion extends the robot's movement space and flexibility. However, the jumping performance is influenced by multiple factors such as driving force, rowing trajectory, and robot structure. The interaction force between the robot and water surface is complicated due to water deformation, and the difficulty of the water jumping increases with the robot's scale. This article designs a miniature water jumping robot with rowing driving legs. The hydrodynamic model between driving legs and water is established based on the modified Wagner theory with consideration of water surface deformation. Particularly, the dynamic model of the robot for the whole jumping process is also developed related to multiple factors. Then, the jumping performance is improved by optimizing the energy storage modality, rowing trajectory, and supporting leg shapes through the theoretical analysis and experiments. The fabricated robot weights 91 g, and its length, width, and height are 220, 410, and 95 mm, respectively. The maximum water jumping height and distance are 241 and 965 mm.