A Sliding Mode Control For Systems With Mis-matched Uncertainties

Conventional sliding mode control can only deal with system uncertainties that satisfy a structural condition called the matching condition. This thesis proposes a new sliding mode control for systems with arbitrarily structured mis-matched uncertainties. The unique feature of the new control is a robust observer for estimation of the external state of the system. The robust observer uses both the loop transfer recovery (LTR) design and variable structure
system (VSS) design to ensure asymptotic estimation. The new control is capable of achieving asymptotic output tracking in the face of large matched or mis-match uncertainties.