ALGEBRAIC INTEGRAL BARRIER LYAPUNOV-BASED EVENT-TRIGGERED NONSMOOTH CONTROL FOR N-DOF ROBOTIC MANIPULATORS UNDER NON-LIPSCHITZ UNCERTAINTIES

Abstract

This study aims to develop a robust control framework for robotic manipulators operating under non-Lipschitz uncertainties and strict state constraints. A novel Algebraic Integral Barrier Lyapunov-Based Event-Triggered Nonsmooth Control (AIBET-NSC) strategy is proposed to achieve fixed-time convergence while minimizing control effort. The method integrates four key components: (i) an algebraic integral observer for noise-resilient state estimation, (ii) a barrier Lyapunov function to strictly enforce joint constraints, (iii) a nonsmooth sliding-mode-based term for fixed-time stability, and (iv) an event-triggered mechanism to reduce control updates. Theoretical analysis proves global fixed-time stability and Zeno-free triggering. Simulation results on a 2-DOF robotic manipulator demonstrate that, compared with conventional sliding mode control, the proposed AIBET-NSC achieves 35-40% lower control torque oscillation, 28% faster settling time, and over 50% fewer control updates, while maintaining accurate trajectory tracking. These results verify the controller’s strong robustness, chattering suppression, and practical feasibility. The proposed framework provides both theoretical and practical contributions toward efficient and constraint-safe control of robotic manipulators under complex uncertain environments.