The concept design of a mobile amphibious spherical robot for underwater operation

Abstract

The existing underwater robots is less steerable at low speeds and special devices are needed for the deployment and recovery of these robots. This makes it unsuitable for the tasks such as underwater inspection and manipulation, especially when cost is strictly restricted. For the design of underwater robots with high mobility and autonomy, in this paper an amphibious robot is proposed. This robot is spherical with two arms outside the spherical hull. The spherical design gives it the ability to roll on the ground. So the robot can autonomously head to the target water without human intervention. This will reduce the cost and enhance its autonomy. The robot employs screw propellers mounted on the two arms for underwater propulsion. With the rotation of the arms the direction of the thrust can be adjusted, so to realize thrust vectoring which can enhance its mobility to a large extent. The arms can also be used for underwater manipulation and for the realization of center of gravity adjustment. The latter will enhance its stability when used for underwater operation. The structure design and motion principle of the robot is given in detail. The dynamics of the robot is also established. The flow field of the robot is numerically simulated for the validation of the design concept.