Mixed Norm Control of a Helicopter

Presented is the design and analysis of robust full authority e ight controllers to improve the handling qualities of a e y-by-wire Bell 205 helicopter. The emphasis is to meet stringent U.S. Army handling qualities specie cations against the constraint of robust stability. The designer goal is to reproduce specie cations constituting an ideal target model in the actual Bell 205, which does not naturally exhibit good handling qualities. A solution to robust e ight controllers is a mixed-norm control design methodology that incorporates both optimal nominal modelfollowingperformanceandrobuststabilityobjectives.Mixed-norm optimizationaddressesanoutstandingproblem inhelicoptere ightcontrol, which hasbeen theunrealisticmapping ofmultipledesign objectivesinto a single norm. Errordynamicsbetweentheresponseofthemodelandtheactualhelicopterareexplicitlydee nedfromexperimental data to reducetheperformancevsrobustnesstradeoff. Themixed-norm control problem addresses genuinesystem requirements without compromise. Analysis and simulation results show an effective robust controller designed for the Bell 205.