Extended state observer augmented finite-time trajectory tracking control of uncertain mechanical systems

Abstract

The problem of finite-time trajectory tracking control is researched for uncertain nonlinear mechanical systems. The non-singular terminal sliding mode controller based on extended state observer is proposed to ensure the tracking errors converge to a small neighborhood of zero in a finite time. The extended state observer is employed to estimate the parametric uncertainties and external disturbances. The non-singular terminal sliding mode control scheme is adopted to avoid the singularity of traditional terminal sliding mode control. The boundary layer technique is adopted to attenuate the chattering phenomenon. Moreover, the finite-time convergence stability of closed-loop system is proved strictly in the Lyapunov framework. Numerical simulation results of robot manipulators and practical experimental results on KINOVA platform illustrate the effectiveness of the proposed controller.