U-parameter design example: robust flight control for wind-shear protection

U-parameter design theory is applied to the design a fixed controller which simultaneously stabilizes a landing flight control system in wind-shear conditions (unstable dynamics) and non-wind-shear conditions (stable dynamics). Data from the Eastern airlines flight 66 which crashed at Kennedy International Airport, June 25, 1975, are used. The resulting compensator requires only flight path angle measurements. The free strongly-bounded-real function which constitutes the U-parameter in this case is used to optimize, in a mean-squared sense, the no-wind-shear flight dynamics. An advantage of the U-parameter theory is that relatively simple controllers can be explored without loss of stability