A new concept spherical underwater robot propelled by thrust vector synthetic jet actuator

Synthetic jet is a new type of underwater propulsion method with the merit of small size, compact structure, light weight, high efficiency and minimal effect on the drag profile of the vehicle. In this paper, a new concept spherical underwater robot propelled by thrust vector synthetic jet actuator is proposed. The synthetic jet actuator has an adjustable flexible nozzle actuated by 3 ropes uniformly distributed around the axis of the nozzle with the spacing of 120°. By deflecting the angle of the nozzle, the direction of the thrust can be adjusted, so to realize the 6 DOF's motion of the robot. The design of the robot makes it very compact in structure and gives it the ability to maneuver in confined environments. All of which make it competent for the observation tasks such as underwater infrastructure inspection or marine creature monitoring. The structure design of the robot and the thrust vector synthetic jet actuator is given in detail. The dynamic model of the robot is given which can be used to control the 6 DOF motion of the robot. The flow field of the robot with different nozzle deflection angle is given through numerical simulation.