Investigation of a New Hovering Autonomous Underwater Vehicle for Underwater Missions

Abstract

It is impossible to implement very tasks by diver, because of complexity of underwater environment and high pressure in the deep sea. These tasks can just be done by a vehicle that includes all special requirements such as: high maneuverability, precise controllability, and especially hovering capability. Underwater robots are integral parts of the industry and marine science. The application of the underwater vehicles has increased with the development of the activities in deep sea. This paper presents a special Hovering type Autonomous Underwater Vehicle (HAUV) for underwater missions. To provide the most suitable and efficient formation of vehicle thrusters for reduction of complexity of control strategies and control of the most degrees of freedom, in this paper, a new thrusters' configuration is investigated, in terms of number of the thrusters, position and the thrust direction of the thrusters. The state feedback controller is designed according to the linear dynamic model and then applied to the non-linear model to validate the controller performance. Designed controller consists of three controllers: horizontal plane controller, vertical plane controller and surge controller. The last controller is developed to control the forward speed. For examination of the system behavior in presence of environmental disturbance and hydrodynamic coefficients uncertainty, the robustness of controller is also investigated.