Sliding Mode Control with exponential and finite-time reaching laws in heading control for autonomous sailboats

This paper presents a model-based nonlinear control approach using Sliding Mode Control (SMC) and a data fitting approach to enhance the practical implementation of heading control for autonomous sailboats. Two controllers are proposed based on the exponential reaching law and the finite-time reaching law, ensuring Lyapunov stability with distinct convergence characteristics. To approximate the lift and drag coefficients in the sailboat dynamic model, a least squares fitting approach is utilized to reduce the number of tuning parameters. In addition, robustness validation considers the case in which only partial lift and drag coefficient data are available. These key contributions enable practical implementation without full system identification. The effectiveness of the proposed controllers is evaluated through simulations, focusing on tacking and jibing maneuver scenarios under external disturbances and model uncertainties. Simulation results confirm the robustness of the proposed controllers and demonstrate that they successfully stabilize the heading error, achieve a trade-off between settling time and overshoot, and outperform a baseline controller during the jibing maneuver scenario.