Approximability properties for second-order sliding mode control systems

New definitions of approximability are presented for nonlinear second-order sliding mode control systems. Such robustness properties are compared with those already known for first-order methods. Sufficient conditions are obtained for second-order regularization, a sliding error estimate is derived, and some relevant examples are discussed. Index Terms--Approximability, nonlinear uncertain control systems, regularization, second-order sliding mode control.