Performance and stability analysis of an autonomous underwater vehicle guidance and control

The main focus of this paper is taken on the direct solution to the nonlinear autonomous underwater vehicle (AUV) dynamics including the performance and stability of a proposed controller without any restricting assumptions on the AUV´s angles during the diving process. Because assumptions may cause severe result in practical applications, Six Degree of Freedom (6DOF) dynamic modeling has been taken into consideration. In fact, performance and stability of AUV has become the most important issue related to nonlinear control problems. In this paper a simulation for modeling and control of motion of an underwater vehicle in 6DOF is presented. Two main controllers are designed to control the depth and the heading of the underwater vehicle. Also, a pitch, yaw and roll attitude controllers are designed to keep the vehicle at a constant depth. Combining the useful properties of each one to improve the performance and stability of the overall controller. The resulting nonlinear control design is formally shown and it yields global asymptotic convergence of the AUV to the path. Phase plane analysis is used to study the stability. Simulation results are presented to demonstrate performance of the proposed method.