Stable Backstepping Control of Marine Vehicles with Actuator Rate Limits and Saturation

A six degree of freedom nonlinear control law for the trajectory tracking of marine vehicles that operate in the presence of unknown time-varying disturbances, input saturation and actuator rate limits is developed using a disturbance observer and nonlinear backstepping. The disturbance observer provides estimates of the unknown time-varying disturbances and a continuously differentiable function is employed to model input saturation. The uniform ultimate boundedness of all signals in the closed-loop control system is proved. Trajectory tracking simulations of an autonomous underwater vehicle demonstrate the performance of the proposed controller. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.