Adaptive Sliding Mode Tracking Control for Uncertain Euler-Lagrange System

• Published in: IEEE access 2019, Vol.7, p.56817-56825
• Main Authors: Song, Zhankui, Sun, Kaibiao
• Format: Article
• Language: English
• Subjects: Actuators; Adaptive algorithms; Adaptive compensation; Adaptive control; Adaptive systems; Closed loops; Control theory; Fault tolerance; Fault tolerant systems; Feedback control; Fuzzy logic; fuzzy logic system; Mode tracking; Nonlinear systems; Saturation; Sliding mode control; Stability analysis; Tracking control; Tracking errors; uncertain Euler-Lagrange system
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2019.2914024

This paper proposes an adaptive feedback control strategy-based sliding mode control technique for the EL system with actuator faults and system uncertainties. In order to obtain magnitude limited control input signal, an approximate saturation function is employed to approximate the real saturation with arbitrarily prescribed precision, and then, an auxiliary variable consists of virtual control law and adaptive control law equipped with the fuzzy logic system is introduced to compensate the adverse influence caused by uncertain nonlinear term. Specifically, on-line adaptive algorithm is derived in the sense of Lyapunov stability analysis in the closed loop design. The rigorous theoretical analysis demonstrates that the proposed control law can guarantee all the closed-loop signals, which are semi-globally uniformly ultimately bounded, and the tracking error converges to a small neighborhood of origin.