Nonlinear Estimator-Based Funnel Tracking Control for A Class of Perturbed Euler Lagrange Systems

Abstract In this paper, a nonlinear estimator-based perturbation rejection funnel control method is investigated for a class of Euler-Lagrange (EL) systems to deal with the trajectory tracking problem against perturbations. To reinforce the perturbation rejection ability, perturbation estimators with nonlinear dynamics are established by employing a filtering operation, which results in asymptotic error convergence. Besides, by devising funnel variables with an exponential decaying function, a funnel control strategy is constructed to ensure tracking errors converging into a prescribed region. The tracking errors of Euler-Lagrange systems are concluded to be ultimately uniformly bounded via Lyapunov stability theory, as well as the controlling deviations are ensured to be restricted into the funnel boundary. Finally, simulations validate the effectiveness of the developed control technology.