A multi-channel $$\varvec{H}_\infty $$ preview control approach to load alleviation design for flexible aircraft

Abstract

Gust load alleviation functions are mainly designed for two objectives: first, alleviating the structural loads resulting from turbulence or gust encounter, and hence reducing the structural fatigue and/or weight; and second, enhancing the ride qualities, and hence the passengers’ comfort. Whilst load alleviation functions can improve both aspects, the designer will still need to make design trade-offs between these two objectives and also between various types and locations of the structural loads. The possible emergence of affordable and reliable remote wind sensor techniques (e.g., Doppler LIDAR) in the future leads to considering new types of load alleviation functions as these sensors would permit anticipating the near future gusts and other types of turbulence. In this paper, we propose a preview control design methodology for the design of a load alleviation function with such anticipation capabilities, based on recent advancements on discrete-time reduced-order multi-channel $$H_\infty $$ H ∞ techniques. The methodology is illustrated on the DLR Discus-2c flexible sailplane model.

Robust Direct Current Control of Single-Phase PWM Rectifiers Based on a Mixed H2/H∞ Controller

“…Robust controllers have been discussed for a variety of applications, including aircraft (Khalil & Fezans, 2021;Azar et al, 2019) and traction systems (Rigatos et al, 2015). These controllers suffer from some limitations namely, their performance is sacrificed in order to gain robustness.…”

Aeronautics Application of Direct-Detection Doppler Wind Lidar: An Adapted Design Based on a Fringe-Imaging Michelson Interferometer as Spectral Analyzer

“…This allows the derivation of mechanical loads based on turbulence input [25], where the latter may be discrete gusts or continuous turbulence as defined in the regulatory framework documents [12]. Another block within the simulation ensemble is the feedforward gust load alleviation (GLA) controller itself, with the controller design based on a new multi-channel structured discrete time H ∞ formulation [28]. Within the iterative simulation, it may be compared to the load control performance of a basic (feedback) controller.…”