Development of a simulation environment for ground control laws design

Thiago Degaspare¹; Pedro Paglione¹; Cleverson Marinho²

¹ Instituto Tecnológico de Aeronáutica; ² Embraer

doi:10.20906/CPS/COB-2015-0499

Resumo

Flight controls systems based on fly-by-wire technology are a common practice in the modern aeronautical industry. Their advantages are associated with pilot load work reduction, handling qualities improvements, structural loads optimization and envelope protection, during different flight phases. A common use of on-ground control law is tail-strike protection, in which pitch attitude is limited in order to avoid a tail strike during takeoff rotation. However, few studies in the literature are dedicated to the influence of on-ground dynamics on the aircraft behavior and control law design. This work aims to explore this gap by the development and study of an aircraft model contemplating not only aerodynamic aspects but also on-ground dynamics, achieving a better understanding of its influence on the aircraft behavior and driving requirements that serve as inputs for control laws design. The model is based on a low wing twin jet engine high performance aircraft. A study is proposed, in which the nonlinear model is used for trimming the aircraft in different phases during takeoff and linear models are derived for aircraft rotation. These are used to understand the influence of on-ground dynamics in terms of stability and control of the aircraft. This practice allows to address characteristics introduced by the highly non-linear on-ground dynamics that otherwise would be neglected, thus improving results on control law design.

Palavras-chave: simulation; on-ground dynamics; aircraft trim; fly-by-wire; stability and control