Sliding Mode Control Method Based on a Fuzzy Logic System for ROVs with Predefined-Time Convergence and Stability

This paper presents a predefined-time control approach to address slow convergence and instability in the orbit control of remotely operated vehicles (ROVs). The proposed method introduces tunable predefined-time stability (PTS), allowing precise adjustment of the system’s stability time through configurable parameters, thereby enhancing controller adaptability. A control input system ensures PTS is developed, while a fuzzy logic system (FLS) is employed to estimate unstructured uncertainties and disturbances. This integration improves robustness, reduces chattering, and eliminates singularities, making the approach well suited for systems with incomplete or unknown model data. Comprehensive simulations validate the effectiveness of the proposed method, demonstrating superior performance compared to existing control strategies and highlighting its potential for advanced ROV applications.