.Yet,theexact estimation of h in (5) is not realizable, and the performance of the sliding phase is degraded resulting in a compromise among chattering, tracking accuracy, and robustness, which are not consistent with the claim “The concept of integral sliding mode can also be extended to construct a new type of perturbation estimator that solves the chattering problem without loss of robustness and control accuracy.” in [14, Sec. 7].