In this paper, a new H∞ performance preserving frequency-weighted controller order reduction with exact solution for low-order weights is
proposed. Given a stabilizing controller that must be stable and satisfy an H∞ performance bound on the closed-loop systems, we derive a sufficient condition for reduced-order controllers to be stabilizing and satisfy the same performance bound, i.e approximation of high-order controllers without degrading the achieved closed-loop performance. The sufficient condition is expressed as a norm bound on frequency-weighted error between the full-order controllers and the reduce-order controllers. The resulting reduced-order controllers may be obtained in the based on a parameterized closed-form solution. The order of the corresponding weights is considerably lower than those of the other previously proposed methods
