Accession Number : ADA273831

Title :   Flight Controller Design Using Mixed H2/H Infinity Optimization with a singular H Infinity Constraint.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Luke, James P.

Report Date : DEC 1993

Pagination or Media Count : 135

Abstract : This thesis explores the effectiveness of mixed H2/H Infinity optimal control design applied to a realistic flight control problem. The application used by this thesis is a single input single output problem dealing with a normal acceleration command following model of the AFTI F-16. The mixed H2/H Infinity control problem is broken into its component H2 and H Infinity parts; the H2 part is formulated as an LQG problem, and a weight is applied to system sensitivity in the H Infinity problem to obtain tracking performance. The sensitivity weight in the underlying H Infinity part results in a singular constraint on the mixed problem. A newly-developed numerical technique is applied and solutions are obtained for controllers of order equal to, first, the order of the underlying H2 problem and, second, the order of the underlying H Infinity problem. Performance characteristics of these controllers are compared to controllers designed using the more-conventional LQG/LTR design method. The results indicate the potential for controllers obtained through mixed H2/H Infinity optimization to provide excellent performance and robustness characteristics at orders less than those obtained through LQG/LTR. Since this conclusion grows in significance when applied to multiple input multiple output (MIMO) problems, a three input, five output example is introduced and the underlying H2 and H Infinity problems for two solution approaches are formulated. Mixed H2/H Infinity Optimization, H2 Optimization, H Infinity Optimization

Descriptors :   *OPTIMIZATION, *SYSTEMS APPROACH, *FLIGHT CONTROL SYSTEMS, ACCELERATION, OUTPUT, SENSITIVITY, THESES, TRACKING, WEIGHT, AIRCRAFT NOISE, AIRCRAFT MODELS, INPUT.

Subject Categories : Flight Control and Instrumentation

Distribution Statement : APPROVED FOR PUBLIC RELEASE