2Utkin V I. Sliding mode control design principles and application to electric drives[ J]. IEEE Transaction on Industrial Electronics, 1993, (40) : 23 - 36.
3QI M, SUN L, WANG X, et al. High Gn Shock-cushioningand Energy-absorption-performance Analysis onAluminum Foam-polyurethane Composite[J].Metallurgical & Mining Industry, 2015, 7(3): 303—310.