This paper examines the use of quantitative crossfeed design followed by diagonal feedback design to decouple, stabilise and improve the handling qualities of the UH-60 Black Hawk helicopter near -hover. The flight configurations used were classified according to the likelihood of their occurrence in practice and this allowed the performance for usual cases to be improved by a trade off with reduced but still quantitative performance for less usual operating conditions. The design wa based on a set of linear models obtained from a non-linear model with six-degree-freedom rigid fuselage with rigid rotor blades, each with a flap and lag degree-of-freedom. The Perron root of the interaction matrix is used as a measure of the level of interaction of uncertain multivariable plants and the crossfeed design seeks to reduce the interaction index before quantitative design of a diagonal controller matrix is attempted. lf the interaction index can be made less than unity by the design, stability of the diagonal loop designs guarantees the stability of the closed loop multivariable system. The performances are evaluated against some of the requirements of the Aeronautical Design Standard, ADS33D, for near-hover flight.
All articles published by Studies in Informatics and Control (SIC) are published in accordance with the terms and conditions of the Creative Commons Attribution License (CC BY-NC-SA 4.0).