A robust predefined-time stable tracking control for uncertain robot manipulators

In this paper, a novel robust predefined-time approach is proposed for global predefined-time tracking control of uncertain robot manipulators. With the sufficient consideration of the effects of uncertainties and external disturbances (UED) on the trajectory tracking performance of robot manipulators, a singularity-free robust control with an auxiliary nonlinear vector is constructed for the predefined-time tracking. The global predefined-time stable tracking by using Lyapunov stability theory has been accomplished for ensuring that both the position and velocity tracking errors arrive at the origin within a predefined time. The proposed approach has the following advantages: (i) the proposed approach with a simple structure is easy to implement with the global robust predefined-time tracking control; (ii) the convergence time of the proposed approach independently of the initial states can be given as an exact controller parameter in advance; (iii) the proposed approach is easy to apply into uncertain robot manipulators with time-constraints tracking control. Extensive simulation and experimental results have been accomplished to show the effectiveness and improved performances of the proposed approach.