Reduced-order H∞ controller synthesis using a real-coded genetic algorithm

It is difficult to design a less conservative reduced-order H_∞ controller presently. We propose a method of designing a less conservative reduced-order controller by using a genetic algorithm. Since it is difficult to search for a reduced-order controller directly, we search for the full-order controller whose reduced-order controller has the approximate performance of the H_∞ optimal full-order controller by adopting controller parameterizations. Then, it is reduced by a certain reduction technique. We propose a coding that is to search only a set of all optimal full-order controllers, since the desired full-order controller is expected to be one of numerous optimal full-order controllers. In order to show the effectiveness of the proposed method, the numerical example is given.