An integral SMC based approach to time-delay system tracking

Output tracking in SISO fully linearizable nonlinear systems with a time delay is considered using integral sliding mode control based technique. Using Padé approximations for the delay, the actual delayed output is replaced by its approximation, by which the problem is reduced to the tracking of a nonminimum phase control system. This system is transformed into a corresponding state tracking problem, where the state tracking profiles are generated by the equations of the stable system centre. The integral sliding mode control approach is developed and good output tracking results are obtained. Smith Predictor is used to compensate the difference between the actual delayed output and its approximation and sliding mode observer/first order exact sliding mode differentiator is used to deal with the perturbed system. A one-link robot arm example is used to show the effectiveness of this proposed method.