Robust Optimal Control Design Using Sensitivity Dynamics and Youla Parameterization

A new methodology for parametric sensitivity based robust optimal control sysnthesys (PS-ROCS), is presented for robust optimal control synthesis using augmented plant dynamics with sensitivity co-system. Robustness of the control system to parametric uncertainties is ensured by minimizing the energy in the states where state vector incorporates states of the sensitivity co-system. The sensitivity dynamics is developed for the first-order parametric sensitivities from the system dynamics. This paper uses the Youla parameterization approach for controller synthesis. The robust optimal design methodology is demonstrated using a linearized model of double slider mechanism. For comparative study, two control designs obtained using the proposed methodology is compared with the H _∞-based design. It was observed that the new methodology presents a viable alternative for robust optimal control design. The attractiveness of the proposed approach lies in the fact that no uncertainty estimates are needed as parametric sensitivities are directly minimized.