Probabilistic Approach to Aircraft Performance Enhancement in Atmospheric Turbulence

The aircraft response to atmospheric turbulence and the related ride quality problem are revisited through a probabilistic approach. The aircraft performance is characterized by means of the probability of exceeding an acceleration value belonging to a Ž xed range of interest. This formulation constitutes an important improvement with respect to a classical approach where only mean information is employed, such as the root mean square acceleration value in one or more fuselage stations. Key features of the proposed algorithm are 1) the possibility of modeling some parameters (like the aircraft derivatives) as random variables with given probability density functions, 2) the possibility of Ž nding the best (in a probabilistic sense) ride quality controller in a candidate set, 3) the availabilityof information about the most important parameter that must be controlled to improve the design, and 4) the possibility of obtaining more rational information about the controller robustness with respect to a standard approach. A detailed example demonstrates the effectiveness of the proposed methodology.