Development of a Robust DIFTSTSMC Controller for Underwater Gliders: Modeling and Performance Optimizations

Abstract

This thesis presents a first-principle based dynamic model for underwater gliders, capturing key forces like hydrodynamic drag, buoyancy, added mass, and nonlinear couplings. Designing a robust controller for underwater gliders is challenging due to their nonlinear and under-actuated dynamics. This thesis proposes a Double Integral Finite- Time Super-Twisting Sliding Mode Controller (DIFTST-SMC) to achieve precise trajectory tracking and disturbance rejection in the presence of external forces. The study focuses on the longitudinal and vertical-plane dynamics of the glider. The control strategy combines integral sliding mode and super-twisting algorithms to ensure finite-time convergence and minimize chattering. To enhance performance, Red Fox Optimization (RFO) is applied to optimize the controller gains. The proposed approach is validated using simulation data. Results demonstrate improved tracking accuracy and robustness compared to conventional sliding mode control methods, highlighting the effectiveness of the combined control and optimization framework.