Robust adaptive uniform exact tracking control for uncertain Euler–Lagrange system

ABSTRACT

This paper offers a solution to the robust adaptive uniform exact tracking control for uncertain nonlinear Euler–Lagrange (EL) system. An adaptive finite-time tracking control algorithm is designed by proposing a novel nonsingular integral terminal sliding-mode surface. Moreover, a new adaptive parameter tuning law is also developed by making good use of the system tracking errors and the adaptive parameter estimation errors. Thus, both the trajectory tracking and the parameter estimation can be achieved in a guaranteed time adjusted arbitrarily based on practical demands, simultaneously. Additionally, the control result for the EL system proposed in this paper can be extended to high-order nonlinear systems easily. Finally, a test-bed 2-DOF robot arm is set-up to demonstrate the performance of the new control algorithm.

KEYWORDS:

• Euler–Lagrange system
• uniform exact control
• fixed-time stability
• parameter estimation
• integral terminal sliding-mode

Acknowledgment

This work was supported by Program for the Outstanding Young Innovative Talent, Nature Science Foundation of Hebei Province (F2016203467), the Postdoctoral innovative talents support program, the National Natural Science Foundation of China (61273222, 61290322, 61322303, 61473248, 61573301, 61603330, 61673335).

Disclosure statement

No potential conflict of interest was reported by the authors.