“…The most common approaches are adaptive schemes (Tao and Kokotovi¢, 1994;Wang et al, 2004;Zhou et al, 2006;Ibrir et al, 2007), fuzzy systems (Kim et al, 1994;Oh and Park, 1998;Lewis et al, 1999), neural networks (Šelmić and Lewis, 2000;Tsai and Chuang, 2004;Zhang and Ge, 2007) and variable structure methods (Corradini and Orlando, 2002;Shyu et al, 2005). Many of these works (Tao and Kokotović, 1994;Kim et al, 1994;Oh and Park, 1998;Šelmić and Lewis, 2000;Tsai and Chuang, 2004;Zhou et al, 2006) use an inverse dead-zone to compensate the negative effects of the deadzone nonlinearity, even though this approach leads to a discontinuous control law and requires instantaneous switching, which in practice cannot be accomplished with mechanical actuators.…”