Complement to ‘Second-order terminal sliding mode controller for a class of chaotic systems with unmatched uncertainties’ [Commun Nonlinear Sci Numer Simulat 15 (2010) 3241–3247]

Owing to the singularity problem having not been considered in control design process, we present some points to improve the results of paper [Wei Xiang, Yugao Huangpu, second-order terminal sliding mode controller for a class of chaotic systems with unmatched uncertainties, Commun Nonlinear Sci Numer Simulat 15 (2010) 3241–3247].