Adaptive sliding mode backstepping output tracking controllers for feedforward uncertain systems

Methods for control design for nonlinear feedforward uncertain systems are considered in this paper. These systems are not usually transformable to the parametric semi-strict feedback form, and it may include unmatched uncertainties consisting of disturbances and unmodelled dynamics. The design methods are based upon (i) the backstepping approach, and (ii) a combination of sliding mode and backstepping. A comparison method of the dynamic and static backstepping methods is presented by applying two methods on a gravity-flow/pipeline system.