Robust backstepping non‐smooth practical tracking for nonlinear systems with mismatched uncertainties

• Published in: International journal of robust and nonlinear control 2022-04, Vol.32 (6), p.3674-3695
• Main Authors: Yang, Wenlong, Shi, Zongying, Zhong, Yisheng
• Format: Article
• Language: English
• Subjects: Compensators; Controllers; finite‐time convergence; Nonlinear systems; robust backstepping tracking control; Robust control; signal compensation theory; Tracking control; uncertain nonlinear system; Uncertainty
• ISSN: 1049-8923; 1099-1239
• DOI: 10.1002/rnc.5976

This article investigates the robust finite‐time output tracking control problem for a class of uncertain nonlinear systems subject to mismatched uncertainties and external disturbances. The nonlinear systems with nonstrict‐feedback form are considered, which possess unknown control coefficients and uncertainties bounded by nonnegative convex functions. Based on signal compensation theory and backstepping methodology, a new robust finite‐time controller is proposed, which incorporates a non‐smooth time‐invariant controller to achieve finite‐time convergence property and a robust compensator introduced to restrain the influences of uncertainties. With the help of finite‐time Lyapunov theorem, the robust finite‐time tracking performance of the closed‐loop system is proved. Finally, two simulation examples are given to validate the effectiveness of the proposed control approach.