부산대학교 도서관

This paper proposes a novel UDE-based nonlinear path-following (PF) control scheme for the underactuated autonomous underwater vehicle (AUV) with multiple uncertainties and input saturation. Firstly, to overcomethe drawback of dependence on the accurate mathematical model, the unknown time-varying sideslip angular speedin the error dynamic model is treated as kinematic uncertainty, and the linear superposition of parameter uncertainties, environmental perturbations, and other unmodeled dynamics is regarded as lumped dynamic uncertainty. Bothkinematic and dynamic uncertainties are estimated and compensated by the designed uncertainty and disturbanceestimators (UDEs). Secondly, a novel augmented backstepping controller based on the estimates generated by UDEsis proposed to achieve PF control of the underactuated AUV. The nonlinear tracking differentiator (NTD) is adoptedto prevent the “explosion of complexity” inherent in the traditional back-stepping method, and the auxiliary dynamical system is utilized to solve the issue of input saturation. Lastly, the stability analysis of the entire enclosed-loopframework is presented. Simulations and comparative analyses are presented to demonstrate the effectiveness androbustness of the presented strategy