3D printing technology-based an amphibious spherical robot

It has long been recognized that the employment of underwater robots have important practical significance, which includes pipe survey, oceanic search, under-ice exploration, mine reconnaissance, dam inspection, ocean survey and so on. Owing to the limitation of underwater environment, some regular sized robots are not suitable for limited spaces. Thus some micro-robots appeared, while sacrificed important abilities such as locomotion velocity and enduring time to achieve compact sizes. Then a mother-son robot system was proposed in our previous researches, which included several micro-robots as sons and an amphibious spherical robot as the mother. The mother robot was adopted to make up for the shortages of microrobots. This paper mainly focused on the structure and mechanism of the mother robot. The mother robot was designed with a spherical structure, which was composed of a fixed hemisphere hull and two operable quarter spherical hulls. It was actuated by four water-jet propellers and ten servomotors, capable of moving on land and in underwater environment. We developed a prototype and evaluated its walking and swimming motions in our previous experiments. Due to some problems in the process of assembly, the motion stability and reliability performed not so well. So, in this paper, we improved the structure and mechanism of the robot based on 3D Printing, which could eliminate some manufacture difficulties, shorten the production cycle, improve water-tightness, and enhance the robot's overall stability, compactness and aesthetics.