Robust Path Following Control of Autonomous Underwater Vehicle Using Combined Time Delay Estimation and Backstepping Method

Abstract

AbstractThe present work addresses the nonlinear control problem for the path following of an autonomous underwater vehicle (AUV) by using the combined backstepping method and time delay estimation (TDE). The proposed controller guides the AUV along a predefined geometric path whilst handling the modelling uncertainties and external disturbances. The control system is developed at two stages: kinematic and dynamic level. At a kinematic level, path following errors are formulated using the path frame, and the desired reference velocities are derived to reduce these errors. At the dynamic level, the actual control force and the moment are obtained to track the desired AUV velocities. The dynamic controller incorporates the time delay estimation method to estimate the unmodelled dynamics and external disturbances. Using Lyapunov stability analysis, the proposed control architecture is proven to be stable, and all the control loop signals are shown to be uniformly ultimately bounded. Finally, numerical simulations are presented to exhibit the controller performance in the face of disturbances and model inconsistencies. The proposed controller performance is compared with the traditional feedback linearisation (FL) control design which lacks robustness property.KeywordsAutonomous underwater vehicleTime delay estimationPath following