Design of fixed order optimal robust controller using simulated annealing

Mathematical models of the plant, in general, are not accurate. The errors in model give rise to model uncertainty. The robust design techniques take care of this. H infin- theory facilitates design of controller using H infin- norm which provides robustness properties. Then a cost function or performance index is selected that represents the quality of the system performance. After a controller structure, a cost function and some constraints have been specified, the problem is posed as nonlinear optimization problem which is solved using the simulated annealing algorithm due to Corona et. al. M-files using MATLAB programming are written for the design and analysis for the design example.