2005 Volume 18 Issue 7 Pages 261-267
In this paper, we consider a vibration isolation control problem in case that narrow-band fre-quency disturbances are applied to a system. The frequency shaping method byH∞control is suitable for the problem. But we can't locate closed-loop poles in preferable region even if we use the robust stability-degree assignment method, because poles of weighting functions of the generalized system become undetectable modes. In order to overcome this problem, we use extendedH∞control combined with the robust stability-degree assignment method. By the method, we can design a controller that provides desirable frequency shaping and preferable closed-loop poles location at the same time. The performance of the designed controller is conformed by experiments.