Adaptive Sliding Mode Tracking Control for Uncertain Euler-Lagrange System

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.