The state-dependent set-point regulation and tracking control of horizontal motion of AUV

This work presents a nonlinear suboptimal semi-coupled steering control of autonomous underwater vehicles (AUVs). Steering control of AUVs most of the times include velocities of the coordinates as state variables. In this work the positions of them are added too. The state-dependent Riccati equation (SDRE) controller is employed to provide suboptimal control law for regulation and tracking problem of the system. Considering this particular type of AUV, REMUS, in steering motion control results control nonlinearities in the state-space equation of the model. These non-affine properties of model promote it to a higher level of complexity with perfection which this work is paid attention to it. Actuator limits are imposed on the system to make the simulations more real. For both set-point regulation and tracking control, simulation results were supported the capability of the SDRE method.