Finite-time trajectory tracking control for under-actuated unmanned surface vessels with saturation constraint

• Published in: Ocean engineering Vol. 249; p. 110745
• Main Authors: Zhang, Lei, Zheng, Yuxin, Huang, Bing, Su, Yumin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2022
• Subjects: Input saturation constraints; Neural networks; Output redefinition; Under-actuated unmanned surface vessels; Under-actuated unmanned surface vessels; Input saturation constraints; Output redefinition; Neural networks
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2022.110745

This article investigates the robust finite-time trajectory tracking control problem of under-actuated unmanned surface vessels (USVs) subject to model uncertainties, saturation constraints, and external disturbances. Firstly, the kinematic and dynamic models of under-actuated USVs are transformed into an equivalent tracking error dynamic by resorting to a novel output redefinition-based dynamic transformation (ORDT). Secondly, a smooth dead-zone operator-based model (DOBM) is introduced to deal with the control input saturation constraints problem. On basis of these, a sliding mode-based controller (SMC) is developed, which possesses the properties of chattering-free and finite-time convergence. Later, Lyapunov stability proved that the proposed control strategy is capable of guaranteeing the boundedness of all closed-loop signals, in spite of the parametric uncertainties, external disturbance, and input saturation constraints. Finally, numerical simulations illustrate the effectiveness of the proposed control approach. •A low computation burden control scheme is developed to enhance the real-time performance in identifying uncertain dynamics.•A novel output redefinition-based dynamic transformation method is proposed to achieve a relative degree of underactuated actuator dynamics.•A dead-zone operator-based model with adaptive scheme is proposed to overcomes the nonlinearities induced by unknown input saturation constraints.