Design and optimization of a deep-sea multimode crawling–swimming hexapod robot with leg-propeller

Abstract

This paper presents the design, optimization and simulation experimental evaluation of a novel crawling–swimming hexapod robot mobile mechanism for coral forest scientific research in the South China Sea. The robot has two modes of seafloor crawling and deep-sea cruising, and it also has two-sided crawling capability. In this paper, a leg structure size optimization model is established in detail, and the single leg can meet the obstacle crossing index after optimizing the size with the help of genetic algorithm. A single-leg dynamics model of legged robot including foot–terrain interaction mechanics and hydrodynamics is proposed in this paper, and an underwater dynamics simulation platform based on Vortex is built on this basis. The experimental results of seafloor crawling simulation show that the robot can steadily crawl up a 20°slope under the condition of 0.15 m/s frontal impact of subsea current velocity. In addition, the simulation results of subsea walking stability show that the stability of tripod, tetrapod and wave gaits gradually increases, but the walking speed gradually decreases. This study provides an important support for the prototype development and underwater gait selection of crawling–swimming hexapod robot.