Dilmi smain1, Bouzouia Brahim2

1 Saad Dahleb University, Department of Aeronautic, Aeronautical Science Laboratory, B.P 270 Soumâa Blida, Algeria.

2 Centre de Développement des Téchnologies Avancées, Cité 20 aout 1956 Baba Hassen, Alger, Algérie.

Abstract
An LQG and weighted H2 / H controller design is presented to establish a nominal performance baseline for the vertical acceleration control of a B-52 aircraft model with flexibility. The aircraft is assumed to be subjected to severe wind gusts causing undesirable vertical motion. We use the Dryden gust power spectral density model to guide the performance specifications and control designs, as well as for time-domain simulations. Motivation for the use of  nominal performance baseline specification is given in terms of a new interpretation of the Dryden model. The H2/H optimal controller is shown to reduce dramatically the effect of wind gust on the aircraft vertical acceleration.

Keywords: flexible aircraft, gust, robust control, flight dynamic, longitudinal aircraft model