High-order robust control design and experiment for a class of uncertain serial manipulators

Abstract

This paper presents a novel robust control algorithm to improve the trajectory tracking accuracy for a class of serial manipulators with unknown uncertainties. Firstly, the manipulators’ dynamics is established based on the Lagrangian method, and the intrinsic properties in the dynamical model of uncertain serial manipulators are investigated, resulting in a better match between the dynamical model and the physical systems. Then, based on the upper bound of the uncertainties, a nonlinear robust controller is designed. Here, a higher-order term is invoked in the controller design to further suppress the influence of the uncertainties. As supported by rigorous proofs, the uniform boundness and uniform ultimate boundness of the controlled manipulator under the designed controller are obtained with the Lyapunov–Minimax method. Finally, a numerical simulation and an experiment of the designed controller are implemented on a two-degree-of-freedom manipulator.