무지향성 수중 로봇을 위한 고정밀 선수각 제어

Abstract

Abstract—Since an autonomous underwater robot can be used as various missions, fast and accurate motion becomes a key issue. In particular, it is definitely needed for missions related to high quality optic and sonar images of specific point such as underwater structure inspection, underwater mapping, underwater surveillance, etc. For those missions, an underwater robot is usually designed to be able to generate omni-directional motion. As one can guess, omni-directional structure brings lots of advantages in fast and accurate motion not only for increasing data quality but also for minimizing energy assumption during overall missions. But, controlling of an omni-directional underwater robot is not easy because the robot is mostly in a transient state with coupled nonlinear and lightly damped yaw dynamics including thruster nonlinearity with dead-zone. This paper proposes a highly accurate heading control scheme for an omni-directional underwater robot consisting of a modelbased robust control with a simple thruster linearization method to achieve fast response time and minimum regulation error. This control scheme is implemented with a hybrid null motion control method that was developed to avoid thruster dead-zone and thruster saturation [1]. The performance is evaluated by the numerical simulation using Matlab.