Sliding Mode Control

This approach forces the closed-loop system trajectories to evolve along a surface in the state-space by means of discontinuous control strategy. The closed-loop system performance is specified by appropriate surface selection, and robustness is ensured via a control law which forces the states to remain on the surface. Theoretically, sliding mode controllers are able to completely reject the effect of a class of uncertainties known as 'matched uncertainties'. This robustness has stimulated research in this area for over two decades. Historically, the theoretical development of sliding mode control ideas took place under the assumption that all the states of the system were available for use in the control law. From an engineering perspective, however, this assumption is untenable and the development of sliding mode theory for the situation where only measurement information is available has been an underpinning theme of our research work for the last decade.