Backstepping Super-Twisting for Robotic Manipulators with Matched and Unmatched Uncertainties

This work investigates the problem of controlling robot manipulators with matched and mismatched uncertainties. To this end, a robust backstepping combined with super-twisting controller is developed to guarantee the convergence of the joint position states to their desired references. The proposed control technique allows the rejection of the uncertainties while eliminating the sliding mode's famous drawback that is the chattering. Based on recursive Lyapunov function, sufficient condition is set to ensure the closed-loop system stability. Finally, simulation and experimental works were carried out respectively on a two degrees-of-freedom robot model and on the seven degrees-of-freedom ANAT modular robot to verify the performance and the robustness of the developed control strategy.