Discrete Sliding Mode Controller on Autonomous Underwater Vehicle in Steering Motion

The purpose of this study is to implement sliding mode control in discrete time domain for Autonomous Underwater Vehicle (AUV). Six Degree of Freedom (DOF) was established for Naval Postgraduate School (NPS) AUV II model, followed by linearizing surge and sway nonlinear Equation of Motion (EoM) in horizontal plane to simplify the control system design. Discrete sliding mode controller was designed based on Gao’s reaching law. Discrete Proportional Integral Derivative (PID) controllers were used for performance comparative analysis and brief discussion on existence of chattering phenomena in the controller input. As a result, computer simulations on NPS AUV II showed that the proposed controller has zero overshoot and faster settling time than the discrete PID controller.