Adaptive twisting sliding mode control for the output tracking of time-delay system

This paper investigates the output tracking problem for the single-input singleoutput (SISO) non-linear system with an output time delay using the twisting sliding mode (SM) control with adaptive gains. Under an appropriate transformation, the SISO non-linear system with relative degree n can be transformed to a relative degree-two system. Padé approximation is involved when considering the output delay problem and this generates a non-minimum phase system, which is considered by the stable system centre approach. Twisting SM control with adaptive gain is used to obtain good output tracking results. A numerical non-linear example is studied to show the effectiveness of this methodology.