A discrete-time terminal sliding mode control for autonomous underwater vehicle

• Main Authors: Sarif, Nira Mawangi, Ngadengon, Rafidah, Jalili, Mohd Hafiz A., Hamdan, Rohaiza
• Format: Conference Proceeding
• Language: English
• Subjects: Autonomous underwater vehicles; Convergence; Dynamic response; Dynamical systems; Motion control; Nonlinear dynamics; Sliding mode control; Underwater robots
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0124665

Autonomous Underwater Vehicle (AUV) are underwater robotic devices intended to explore hostiles territories in underwater domain. Due to highly nonlinear dynamics, uncertain parametric, and unmeasurable ocean behavior, designing of AUV motion control become a challenging task. In this study, a Discrete-Time Terminal Sliding Mode Control (DTSMC) with Reaching Law (RL) scheme is proposed to improve the dynamic response of Naval Postgraduate School (NPS) AUV II in such a way to improve error state convergence performance and reduce chattering effect at the same time. This is accomplished by implementing Nonlinear Sliding Surface (NSS) design in which transformation of the sliding dynamic property take place. The fractional power component provides nonlinear property of the system dynamic in which the error state convergence accelerated to a finite time in the vicinity of the equilibrium point. Additionally, fractional power component guarantees steeper slope of the sliding surface hence the approaching angle of state trajectory is small. Consequently, the chattering magnitude is small. The effectiveness of DTSMC is compared with DSMC and MPC through simulations.