“…The sliding mode approach was originally proposed for controller design (Emelyanov, 1967;Gao et al, 1995;Hung et al, 1993;Levant, 1993;Mnasri and Gasmi, 2011;Sira-Ramirez, 1993;Tomera, 2010;Utkin, 1977;Utkin and Shi, 1996). However, sliding mode techniques can also be used in state observers (Edwards and Spurgeon, 1994;Edwards et al, 2012;Floquet et al, 2007;Fridman et al, 2007;Haskara et al, 1998;Veluvolu and Soh, 2009).…”