Non‐Singular Fast Terminal Sliding Mode Control With Adaptive Reaching Law

ABSTRACT This paper designs an Adaptive Non‐singular Fast Terminal Sliding Mode Control (Adaptive NFTSMC) law for nonlinear dynamic systems. A new variant of Non‐singular Fast Terminal Sliding surface is proposed with a newly designed Adaptive reaching law for quicker convergence and lower control effort. The proposed sliding surface incorporates a new non‐singular fast terminal structure capable of faster finite‐time convergence than its predecessors. The gains of the proposed reaching law are adapted as a function of sliding surface which lowers the control effort while securing improved performance. Asymptotic stability of the designed control law is analytically verified by Lyapunov's method. The proposed control law is validated for load frequency control and trajectory tracking of quadrotors, respectively. Superiority of Adaptive NFTSMC over the competing control methods is demonstrated in simulation in the presence of external disturbance and parametric uncertainty.