Date of Award

12-1991

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Aeronautics and Astronautics

First Advisor

D. Brett Ridgely, PhD

Abstract

The problem of minimizing the 2-norm of one transfer function subject to an infinity-norm bound on another transfer function is examined for increased order controllers. In particular, the theoretical results of the full order case are extended to the higher order case, and SISO and MIMO numerical examples are given for increasingly higher order compensators. Some of the key proofs for higher order compensators include: the global minimum 2-norm is unachievable under output feedback for certain levels of gamma regardless of compensator order; the solution to the mixed H2/H infinity problem lies on the boundary of the infinity-norm constraint for this same range of gamma's; and the suboptimal mixed problem converges to the optimal in the limit for higher order controllers. Also, it is shown that the optimal compensator order for the mixed H2/H infinity problem is greater than the order of the plant under certain conditions, and a conjecture about the optimal order for the mixed problem is made.

AFIT Designator

AFIT-GAE-ENY-91D-14

DTIC Accession Number

ADA243874

Comments

The author's Vita page is omitted.

Plain-text title form: Investigation of the Effects of Increased Order Compensators in Mixed H2/H(Infinity) Optimization

Download

Share

COinS