Stabilization of a parallel platform with unknown disturbances and uncertainties using sliding mode control with hardware validation

This paper presents the design, simulation, and partial hardware validation of a robust control strategy for stabilizing a three-degree-of-freedom (3-DOF) parallel robotic platform under the influence of unknown disturbances and system uncertainties. The targeted application lies within the maritime domain, where external perturbations such as wave motion, wind forces, and mechanical vibrations pose significant challenges to stabilization tasks. A Sliding Mode Control with Boundary-Layer Smoothing (SMC) framework is developed to ensure asymptotic convergence to equilibrium despite these uncertainties. The control scheme is synthesized using a nonlinear dynamic model of the 3-DOF platform and is validated through extensive numerical simulations, demonstrating strong performance in rejecting disturbances and achieving stabilization. To assess real-world applicability, the same SMC law is applied to a simplified two-degree-of-freedom (2-DOF) hardware prototype without structural modifications. The hardware experiments confirm smooth convergence and practical feasibility. The results underscore the effectiveness and adaptability of the proposed SMC design in maintaining stability across different platform configurations, making it a promising solution for maritime systems requiring high-precision pose regulation under uncertain and dynamic operating conditions.