Dynamically synthesized variable structure controller with integral modes

A variable structure strategy for achieving asymptotic output tracking under step reference changes with smooth control actions is presented. The robust controller is designed using an integral part and a dynamical sliding mode component. Thus, the controller features zero steady state error, insensitivity to plant parameters uncertainty and external disturbances, with reduced chattering in the control signal. These characteristics make the approach specially suitable for real process applications. A simulation example and experimental results in a pressurized tank are provided to show the feasibility of the proposed controller.