Design of a novel water jet thruster for amphibious jumping robot

摘要

Conventional jumping robot can only perform jumping motion on land while the amphibious jumping robot under development is capable of jumping and overcoming obstacles in both terrestrial and aquatic environment. This robot‘s outstanding jumping ability are due to its core component–the water jet thruster. In this paper, we introduce a novel water jet thruster powered by liquid nitrogen, including its inner structure, working process and prototype manufacture. Next, a mathematical model for the water jet thruster is built to analyse its parameter variations during working process. The relationship between the volume fraction of water inside the thruster and the jumping height of the thruster is also studied, and the result shows that there usually exists an optimum volume fraction of water for a given set pressure. Especially, the optimum volume fraction of water will rise with the growing of the set pressure. Finally the outdoor aquatic experiment is carried out to validate the reasonability of the theoretical analysis and the practicability of the water jet thruster.